Fig. １  Relationship between surface resistivity and content

 (water-borne coatings with 0.43μm thickness)

 * Haze values are shown in parentheses

Surface resistivity represents the ability of surface electric current. However, the surface resistivity actually measured  tends to decrease as the coating thickness increases due to the influence of the inner electric current.  Fig.2 shows the relationship between surface resistivity and coating thickness.  

The electroconductivity and haze are affected by pigment concentration, dispersion time and coating thickness.  Fig. 3 to 5 show the relationships between two parameters. 

　　Fig.3 Relationship between

 　　pigment concentration and haze

　　Fig.4. Relationship between

　　　　　　　 dispersion time and haze

　　Fig.5 Relationship between

　　　　　　coating thickness and haze

From the results, lower haze can be obtained by lower pigment concentration, stronger dispersion and thinner coating. However, taking the conductivity into account, total quality of the coating film will be improved by making the content higher and the thickness lower.

Fig.6 shows ζ potential of SN-100P.  From neutral to alkaline pH, SN-100P has significantly negative ζ potential. This property is rarely seen in other oxides.  Accordingly, SN-100D, which is water dispersion product of SN-100P, shows superior dispersion stability due to the strong electric repulsion. SN-100D shows excellent stability without adding dispersing agents.