Progress in Color, Colorants and Coatings
Volume:7 Issue: 3, Summer 2014

anionic polyurethane dispersants (APUDs) were used as dispersing agents in formulation of waterborne paints. The APUDs were synthesized by three steps. In the first step, macromonomer diisocyanate having carboxylic acid was prepared by isophorone diisocyanate (IPDI), dimethylol propionic acid (DMPA) in the presence of acetone as solvent and dibutyltin dilaurate (DBTDL) as catalyst. Then, carboxylic polyurethane was prepared by reaction macromonomer diisocyanate having carboxylic acid groups with alcohols. In this work, alcohols were 1,4-butanediol and 1,6- hexanediol as difunctional alcohols, trimethylol propane as trifunctional alcohol and pentaerythritol as tetrafunctional alcohol. The final step involved neutralization and dispersion in water, where acidic polyurethane was neutralized by the addition of triethylamine (TEA). The polymers have been characterized with 1H-NMR and FT-IR. The dispersion of APUDs depends on their molecular weights and chemical structures. Dispersion of titanium dioxide in typical waterborne acrylic resin has been investigated.

two novel alkali clearable disperse dyes were synthesized. 4- fluorosulfonyl aniline and 2-nitro-4-fluorosulfonyl aniline were utilized as the diazo components and 2- naphthol as the coupling component. The DSC, FT-IR, 1H-NMR and UV-Vis analyses were used to characterize the synthesized intermediates and dyes. The synthesized dyes were utilized to dye polyester fibers and their dyeing properties were studied. In addition, hydrolysis kinetics of the synthesized dyes in alkaline media was investigated. The results showed that the synthesized dyes had good properties on polyester fabrics. As a result of the synthesized dyes hydrolysis in alkaline media, the reduction clearing process is supposedly replaced by alkali-clearing process. The elimination of sodium hydrosulfite leads to the reduction of environmental pollution. One of the main advantages of replacing reduction-clearing method by alkali-clearing is preventing toxic and carcinogenic aromatic amines to be produced.

in commercial point of view, it is of great interest to find colors with high color constancy level. Color constancy as a relatively property of object’s appearance could be affected by different factors. In this article, the color inconstancy index (CMCCON02) and the color coordinates were calculated for 1269 samples of Munsell at CIEL*c*hº color system to study any correlations. The corresponding color was determined under four illuminants A, TL84, and a white LED as well as an equal energy spectrum. The results showed that the variation of hue angle and chroma makes more sensible effect on the color inconstancy index CMCCON02 than the lightness. In addition, a specific proportional change in spectral reflectance curve between low and high wavelength limits makes the color to be more inconstant. Besides, the results showed that color inconstancy is depended primarily on the type of color and used illuminant pair.

photo-oxidative stability of a series of most common red acrylic paints has been investigated. The paints in question were carmine, quinacridone scarlet, alizarin crimson, brilliant red, vermilion and cadmium red hue. Structural changes, discoloration and weight loss of paints film subjected to UV irradiation in an accelerated ageing chamber were measured using FT-IR spectroscopy, colorimetry and gravimetric analysis before and after 400, 800 and 1200 hours of irradiation. The results of FT-IR spectroscopy showed that cadmium, quinacridone scarlet, primary magenta and vermilion involved most structural changes, where the reduction of transmission peak at 2900 cm-1 (symmetric stretching of C-H bond) was noteworthy. Colorimetric measurements indicated the reduction in the absorption of visible light due to photodegradation of the pigment structure. Furthermore, alizarin crimson and brilliant red have undergone more weight loss compared to the others, which was a result of rapid formation of VOCs.

aprotective coating was applied onto the phosphated panels using cathodic electrocoating in two different dry film thickness 8μm and 20μm. The corrosion resistance of cathodic electrocoatings was studied using AC/DC/AC method. Twelve cycles of AC/DC/AC tests were carried out for each sample; 6 cycles DC voltage of -4 V Vs. Ag/AgCl for 20 minutes and the other 6 cycles with -4 V Vs Ag/AgCl for 2 hours. During DC potential application, transient electrical current density through the coated substrates was monitored. After each cycle of AC/DC/AC test, bode plotes of samples were investigated. The results showed that by decreasing the thickness of electrocoating, the barrier properties of the film were declined drastically. On the other hand, applying DC potential for a longer time (2 hours) prepared harsh condition for degradation of the coating. The sample with normal thickness (20μm) failed after 6 cycles while the sample with lower thickness (8μm) failed only after 3 cycles.

ultra optical glasses are proposed for attaining noble glazes of high reflection and shine. In addition، these glasses can be used as semimirrors and optical instruments. In this research، attempts were devoted mainly to introduce a glass system with the highest possible refractive index in which the highest reflection is desirable. Thus، different amounts of heavy metal oxides modifiers، such as PbO and Bi2O3 were compounded with Ga2O3 as a glass former، and were melted to determine the stable glass regions in the corresponding three oxide glass systems. Results suggested that the most stable glasses were located in the eutectic region of the above oxides three phase diagram، where the melting point was as low as 900OC. DTA measurements presented glass stability values as the differences between the glass crystallinity and transition temperatures، Tc-Tg. The “Minimum angle of deviation of light in a prism” was employed to measure refractive indices greater than 1. 8، in which the highest results were above the diamond refractive index، i. e. 2. 417. Dispersion property، as Abbe Number، was as low as 10 for the lowest content Ga2O3. Noble glazes or coats can be tailored and fabricated based on these ultra optical glass systems، which possess high reflection and optical non-linearity.

water based inorganic alkali silicate binder of zinc rich primer was modified by adding acrylic resin derivatives. Several series of primer coatings were formulated by adding 5, 10 and 15 wt% of acrylic and acrylic/styrene copolymer to potassium silicate binder and used as binder in zinc rich coatings. The formulated primers were applied on low carbon steel plates and the corrosion protection properties of these primers were evaluated by electrochemical impedance spectroscopy (EIS), corrosion potential measurements, salt fog test and scanning electron microscope (SEM). The results indicated that the addition of 5% acrylic/styrene copolymer and/or 10% acrylic resin into the inorganic silicate binder led to improvement of corrosion protection performance of formulated primers.