Electroconductive particles
An electroconductive particle having a core particle and a tin oxide-containing coating layer on the core particle. The tin oxide of the coating layer has a crystallite size of 70 to 200 Å. The electroconductive particle preferably has a ratio of R 3 to R 1 of 1 to 250, wherein R 1 and R 3 are respective surface resistivities of electroconductive films formed of a coating composition containing the electroconductive particle and prepared by 1-hour dispersing and 3-hour dispersing, respectively. The coating layer preferably comprises dopant element-free, electroconductive tin oxide.
1. An electroconductive particle, comprising:
a core particle comprising titanium oxide, barium sulfate, alumina, or silica; and
a dopant element-free tin oxide-containing coating layer located on the core particle, the tin oxide of the coating layer having a crystallite size of 70 to 200 Å.
2. The electroconductive particle according to claim 1 , wherein the core particle is titanium oxide, and the electroconductive particle shows an apparent density change represented by formula [(A−B)/A×100] of 0% to 20%, wherein A is an apparent density (g/cm 3 ) measured under a pressure of 0.20 N/m 2 , and B is an apparent density (g/cm 3 ) measured under a pressure of 0.02 N/m 2 .
3. The electroconductive particle according to claim 1 , wherein the core particle is barium sulfate, and the electroconductive particle shows an apparent density change represented by formula [(A−B)/A×100] of 0% to 26%, wherein A is an apparent density (g/cm 3 ) measured under a pressure of 0.20 N/m 2 , and B is an apparent density (g/cm 3 ) measured under a pressure of 0.02 N/m 2 .
4. An electroconductive composition comprising the electroconductive particle according to claim 1 .
5. The electroconductive particle according to claim 1 , wherein the core particle has an average particle size of 30 to 500 nm.
6. The electroconductive particle according to claim 1 , having a tin oxide content of 15 mass % or more.
7. The electroconductive particle according to claim 1 , having a tin oxide content of 20 to 60 mass %.
8. The electroconductive particle according to claim 1 , wherein the crystallite size is 72 to 200 Å.
9. The electroconductive particle according to claim 1 , wherein an oxygen deficiency of the tin oxide is defined in terms of tint in CIE L*a*b* color space where L* has a value of 80 to 95, a* has a value of −2.0 to 2.0 and b* has a value of −2.0 to 10.0.
10. The electroconductive particle according to claim 1 , wherein an oxygen deficiency of the tin oxide is defined in terms of tint in CIE L*a*b* color space where L* has a value of 83 to 93, a* has a value of −0.5 to 0.5 and b* has a value of −1.0 to 9.0.
11. The electro conductive particle according to claim 1 , having a ratio of R 3 to R 1 of 1 to 250, wherein R 1 is a surface resistivity of an electroconductive film formed of a coating composition containing the electroconductive particle and prepared by 1-hour dispersing, and R 3 is a surface resistivity of an electroconductive film formed of a coating composition containing the electroconductive particle and prepared by 3-hour dispersing.
12. An electroconductive particle, comprising:
a core particle comprising titanium oxide, barium sulfate, alumina, or silica; and
a dopant element-free tin oxide-containing coating layer located on the core particle, the tin oxide of the coating layer having a crystallite size of 75 to 200 Å.
13. The electroconductive particle according to claim 12 , wherein the core particle is titanium oxide, and the electroconductive particle shows an apparent density change represented by formula [(A−B)/A×100] of 0% to 20%, wherein A is an apparent density (g/cm 3 ) measured under a pressure of 0.20 N/m 2 , and B is an apparent density (g/cm 3 ) measured under a pressure of 0.02 N/m 2 .
14. The electroconductive particle according to claim 12 , wherein the core particle is barium sulfate, and the electroconductive particle shows an apparent density change represented by formula [(A−B)/A×100] of 0% to 26%, wherein A is an apparent density (g/cm 3 ) measured under a pressure of 0.20 N/m 2 , and B is an apparent density (g/cm 3 ) measured under a pressure of 0.02 N/m 2 .
15. The electroconductive particle according to claim 12 , wherein an oxygen deficiency of the tin oxide is defined in terms of tint in CIE L*a*b* color space where L* has a value of 80 to 95, a* has a value of −2.0 to 2.0 and b* has a value of −2.0 to 10.0.
16. The electroconductive particle according to claim 15 , having a ratio of R 3 to R 1 of 1 to 250, wherein R 1 is a surface resistivity of an electroconductive film formed of a coating composition containing the electroconductive particle and prepared by 1-hour dispersing, and R 3 is a surface resistivity of an electroconductive film formed of a coating composition containing the electroconductive particle and prepared by 3-hour dispersing.