An experiment to facilitate the analysis of pigment effects on the mechanical properties of paint films is described. The samples studied were based on unsaturated polyester resin films filled with surface treated glass flakes (I), untreated glass flakes (II) and glass beads (III). Stress-strain properties, dynamic viscoelasticity and degree of swelling for the films of various pigment volume concentration, observation of the fracture surface of the films by scanning electron microscope (SEM) and the adsorption of the vehicle on the pigment surface with gel permeation chromatography (GPC) were investigated. The effects of morphology of pigment particles were also studied. 1) The interaction between the vehicle and I was larger than that between the vehicle and II, and this agrees with the experimental results obtained by GPC, Tg, degree of water absorption, SEM, etc. 2) The tensile strength and the elongation at break for I films were larger than those for II films, while there was little difference in the increasing ratio of the modulus. 3) The reinforcing effect for I or II films was more pronounced than that for III films. These experimental results were examined with the pigment reinforcement theories
In order to investigate the properties of metal chelates of the Group IV elements with ligands of azo dyes and their applications to a pigment or coloring material, titanium and zirconium chelates were synthesized. The reaction of the metal alkoxides (M (OR) 4, M=Ti, Zr, R= (isopropyl) with 2, 2'-dihydroxy and 2-hydroxy-2'-carboxy azo compounds gave the 1 : 2 metal chelates with no charge which were insoluble in water. The titanium chelates were sparingly soluble in organic solvents, but the zirconium chelates had an appreciable solubility in organic solvents. The colors of titanium and zirconium chelates were black and mahogany brown, respectively. The results of measurements of the. lightfastness and thermal stability indicated that the properties were much dependent on the structures of the ligands and the central metals ; the properties of titanium chelates were more superior than those of zirconium ones with ligands of 2, 2'-dihydroxy azo compounds, but some of the titanium. chelates with 2-hydroxy-2'-carboxy azo compounds had a comparable stability.