Abstract: The present invention is intended to provide a technology preventing decrease in an electroconductivity or an throwing power of a cationic electrodeposition coating composition having a lower solid content and/or a lower ash content. Therefore, the present invention relates to: an electroconductivity-controlling agent used for a low solid content type cationic electrodeposition coating composition having 0.5 to 9.0 wt % of solid content of the coating composition, which agent includes an amino group-containing compound having 500 to 20000 of molecular weight and 200 to 500 mmol/100 g of amine value, to adjust an electroconductivity of the composition to 900 to 2000 ?S/cm; a method for adjusting an electroconductivity of a cationic electrodeposition coating composition, which includes steps of: adding an electroconductivity-controlling agent to a low solid content type cationic electrodeposition coating composition having 0.5 to 9.

Abstract: A cationic electrodeposition coating composition having superior defoaming property and being capable of effectively preventing the generation of unevennes of drying is provided.

Abstract: The present invention provides a method of forming a multilayer coating film comprising the step (I) of coating an article to be coated with an electrodeposition coating containing two resin components incompatible with each other followed by curing by heating to form an electrodeposited coating film, the step (II) of applying a water-borne intermediate coating onto the electrodeposited coating film to form an uncured intermediate coating film, the step (III) of applying a water-borne base coating onto the intermediate coating film to form an uncured base coating film, the step (IV) of applying a clear coating onto the base coating film to form an uncured clear coating film and the step (V) of curing the intermediate coating film, the base coating film and the clear coating film simultaneously by heating to thereby obtain a multilayer coating film.

Abstract: This invention relates to a method for boring a large-section tunnel safely and quickly by reinforcing and improving in advance the ground over the full length of the tunnel section, which includes; boring a top drift (2) through the full length of the tunnel (1) section, drilling curved holes inclined in forward or backward directions at an angle of about 45 degrees at preset intervals from the top drift (2) along the peripheral edges of the sections of the tunnel (1) by using ordinary small bore rock drills and curved steel pipes (3), pulling off the steel pipes (3) after inserting injection pipes into the drilled holes, injecting grout into the ground surrounding the tunnel through the injection pipes to develop artificial ground arches (4), excavating the tunnel (1), advancing suspension forms (6) and placing concrete for secondary lining.

Abstract: It is an object of the present invention to provide a method of forming a multilayer coating film by which the multilayer coating film comparable in shock resistance, in particular chipping resistance, to the conventional three-coat films and resistant to yellowing and having a good appearance can be formed in the three-wet coating system which is intended for coating process curtailment, cost reduction and environmental impact reduction.

Abstract: Disclosed is a coating method of intermediate-coating-less, which sufficiently keeps excellent appearance, weather resistance and corrosion resistance equal to a three layer coating in conventional technology. The method of the present invention comprises: electrocoating an aqueous paint composition comprising at least two sort of resins which are insoluble with each other, a curing agent and a pigment, on an electrically conductive substrate, heating it to form a layer separation, and then curing to form a plural layered cured coating having at least two layers, wherein a concentration of the pigment is distributed such that a pigment concentration (a) in the resin layer directly contacting air is relatively higher than a pigment concentration (b) in the resin layer directly contacting the electrically conductive substrate.