Crowd Control Ways to Reduce Dependence on TiO 2 without Sacrificing Key Performance Properties Dave Fasano Linda Adamson Dow Coating Materials American Coatings Show May 7, 2012 Crowding of TiO 2 Well known effect 1,2 Increases with TiO 2 use level TiO 2 Particles are not well separated Decrease in Scattering Efficiency 1.F. Steig; J. of Coatings Tech.; 53; 680; pp 75-79; S. Fitzwater and J. Hook; J. of Coatings Tech.; 57; 721; pp 39-47; 1985 May 7, 2012 Crowding of TiO 2 Decrease in Scattering Efficiency 1.F. Steig; J. of Coatings Tech.; 53; 680; pp 75-79; S. Fitzwater and J. Hook; J. of Coatings Tech.; 57; 721; pp 39-47; 1985 Well known effect 1,2 Increases with TiO 2 use level TiO 2 Particles are not well separated May 7, 2012 Crowding of TiO 2 Decrease in Scattering Efficiency Increasing PVC 1.F. Steig; J. of Coatings Tech.; 53; 680; pp 75-79; S. Fitzwater and J. Hook; J. of Coatings Tech.; 57; 721; pp 39-47; 1985 Well known effect 1,2 Increases with TiO 2 use level TiO 2 Particles are not well separated May 7, 2012 1.F. Steig; J. of Coatings Tech.; 53; 680; pp 75-79; S. Fitzwater and J. Hook; J. of Coatings Tech.; 57; 721; pp 39-47; 1985 Crowding of TiO 2 Decrease in Scattering Efficiency Increasing PVC Well known effect 1,2 Increases with TiO 2 use level TiO 2 Particles are not well separated May 7, 2012 TiO 2 Crowds at High Use Levels May 7, 2012 TiO 2 Crowds at High Use Levels May 7, 2012 How Do Extenders Affect the Crowding of TiO 2 ? Do small particle size extenders space TiO 2 ? Do Latex Binder Particles Affect Crowding of TiO 2 ? Effects studied in below CPVC Paints Above CPVC paints Extenders, especially small particle, contribute to hiding via porosity, but decrease resistance properties Crowding Effect of Extenders and Latex Binders May 7, 2012 Crowding Effect of Extenders Start With an all TiO 2 Paint; 190 pounds; 16 PVC TiO 2 use level remains constant in all paints Commercial Extender and Opaque Polymer; 15 PVC Particle Size: 0.4 to 12 um Calcium Carbonate: natural and precipitated Various Clay/Silicate: kaolin, calcined, delaminated, zeolite Maintain 36% Volume Solids; Adjust Binder Level Total PVC increases: 16 and 31 PVC All paint are below CPVC May 7, 2012 Crowding Effect of Extenders May 7, 2012 Crowding Effect of Extenders May 7, 2012 A Random TiO 2 Distribution May 7, 2012 Becomes Less Random May 7, 2012 Becomes Less Random May 7, 2012 To Make Room for Extenders May 7, 2012 To Make Room for Extenders May 7, 2012 Crowding Effect of Extenders May 7, 2012 A Random TiO 2 Distribution May 7, 2012 Becomes Less Random May 7, 2012 Becomes Less Random May 7, 2012 To Make Room for Extenders May 7, 2012 Crowding Effect of Extenders May 7, 2012 Crowding Effect of Extenders May 7, 2012 Crowding Effect of Extenders Opaque Polymer is a Light Scattering Pigment May 7, 2012 Opaque Polymer A Light Scattering Pigment Difference in refractive index Optimum Scattering Size; about 0.3 um Refraction (Difference in Refractive Index) 2 TiO 2 > Air > Extender MaterialRefractive Index Difference in Refractive Index Latex Polymer TiO Air Mineral Extenders1.5 1.6