PHOTOLYTICALLY INDUCED DEGRADATION--EFFECTS OF PIGMENTS

This article focuses on the use of some pigments to protect coating films against ultraviolet (UV) attack. The role other pigments play in the degradation of coatings by UV is also discussed. Pigment is, in fact, often the primary defense against the UV degradation of coating films. Not all pigments are good UV absorbers. In fact, the extenders as a group are quite transparent to UV. Therefore, they can afford little UV protection in this regard. Pigmentary titanium dioxide (TiO2), especially the rutile form, is an excellent UV absorber; it is also photocatalytic. The oxidative destruction of the binder around the TiO2 particles loosens the particle itself as the binder is reduced to oxidized residues of low molecular weight. Anatase TiO2 is actually a poorer hiding pigment than rutile. Much progress has been made in the design of TiO2 pigments for optimum chalking resistance. Caution is also necessary to avoid other undesirable color changes resulting from combinations of TiO2 and other coating ingredients.

  • Availability:
  • Supplemental Notes:
    • Page Range: pp 54, 56-60, 62-64
  • Corporate Authors:

    Technology Publishing Company

    2100 Wharton Street, Suite 310
    Pittsburgh, PA  United States  15203
  • Authors:
    • Hare, C H
  • Publication Date: 2000-4

Language

  • English

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 9 p.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00792405
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 22 2000 12:00AM