An Experimental Study for the Improvement of the Stain Resistance for Exterior Wall Paints in a Western City in China

In recent years, with the rapid development of the building industry in western cities during the period of “Western Development” in China, the paints industry has developed rapidly and become more mature. In addition, waterborne inorganic exterior wall paints have been a great choice in the building industry because of their reduced volatile organic compounds (VOCs) and less toxicity and odor. However, the problem of stain resistance for exterior wall paints in western cities has not been solved, which has become a major obstacle to the application and promotion of exterior wall paints in western cities in China. Therefore, effective measures should eventually be carried out for improving the stain resistance of exterior wall paints in western cities in China. In this paper, an experimental study on improving stain resistance for exterior wall paints in a typical western city in China, Chongqing, is reported. In the three defined designs, the effects of the paint structure type, the pigment volume concentration (PVC), thickeners, cosolvents and wetting and dispersing agents on the stain resistance of exterior wall paints in a typical western city in China, Chongqing, were examined. The experimental results suggest that the stain resistance of silicone–acrylic paint was the most suitable among the three kinds of tested paints (silicone–acrylic paint, styrene–acrylic paint and pure acrylic paint). In addition, the PVC had a great influence on the stain resistance of the exterior wall paints. The compactness, water absorption and stain resistance of the paint’s film were the most suitable when the PVCs of the paints reached 45%. Furthermore, the tested wetting and dispersing agents made the same contributions to the paints’ stain resistance, as their decline rates for reflectivity were similar. The reflectivity of the film significantly decreased when the ratio of associating thickener to non-associating thickener reached 4:1, and also significantly declined when the content of propylene glycol reached 5%.

Influence of the PVC of Glass Fiber Powder on the Properties of a Thermochromic Waterborne Coating for Chinese Fir Boards

A thermochromic waterborne coating with thermal insulation efficacy was prepared by adding thermochromic microcapsules and glass fiber powder. The influence of the pigment volume concentration (PVC) of a glass fiber powder on the performance of the thermochromic coating for Chinese fir boards was investigated. It was found that a coating with a PVC of glass fiber powder of 0–22.0% had better discoloration properties. When the PVC of the glass fiber powder was more than 4.0%, with the increase of the PVC, the gloss of the coating decreased gradually, while, the adhesion, impact resistance, and liquid resistance were not affected. When the PVC of the glass fiber powder was 10.0%–30.0%, it showed thermal insulation efficacy and high hardness. The coating with a PVC of 16.0% glass fiber powder had better wear resistance. The discoloration property of the coating with thermal insulation efficacy was not affected by time. These results exhibit great potential for the application of a wood surface thermochromic and thermal insulation coating.

Estimation of Rheological Properties of Ash Silicate Paints

Information provided on the color of paint coatings on the mortar substrate, depending on the type of pigment in accordance with the RAL color file. It is shown that presence of glycerin in the composition of the sol of silicate paint promotes an increase in the cohesive strength of coatings, an improvement in the filling of paint, and an improvement in the quality of the appearance of coatings. Information is given on the rheological properties of a silicate paint sol with the addition of glycerin depending on the pigment content. It has been established, that the introduction of glycerin into the paint formulation leads to an increase in the values of the critical volume concentration of the pigment (filler). A model for changing the viscosity of paint from a pigment volume concentration (filler) is proposed.

Electrochemical Impedance Spectroscopy Study of Waterborne Epoxy Coating Film Formation

The film formation process in waterborne (WB) epoxy coatings is studied using electrochemical impedance spectroscopy (EIS) measurements and dynamic mechanical analysis (DMA). Ten epoxy coatings with different pigment volume concentration were prepared on standard steel substrates and carefully monitored over four weeks (30 days). It is shown that impedance spectroscopy can serve as a very sensitive tool for accurate experimental detection of the critical pigment volume concentration. We also show that the optimal film formation process and corrosion stability of coatings are greatly affected by the coating pigment volume concentration (PVC) value. As a whole, the study confirms that the optimization of coating protection ability needs to take into account both maximization of the barrier effect as well as maximization of the degree of epoxy-amino cross-linking.

Development and Regression Modeling of Dirt Resistive Latex Façade Paint

A highly dirt-resistant paint for building façades without chemicals harmful to nature and the environment would resolve the unattractive disfigurement of building walls caused by dirt. The current ranking of Pakistan in terms of air pollution is 139th. A set of dirt-resistant paint formulae was constructed with the aid of computer programming. From this set, the best dirt-resistant paint formula was explored and identified. The final determination of the optimum formulation was based on statistically planned experiments conducted in the laboratory and in a natural environment. In order to achieve high-quality results, the best available laboratory equipment were used. The results obtained were analyzed and conclusions were drawn using appropriate statistical techniques. The procedure started with the selection of appropriate raw materials and generation of a target population of 543,143 paint formulations by adopting Basic Language computer programming. The average pigment volume concentration (PVC) percentage was computed using theory and found to be 54.98% for the target population paint formulations, verifying the literature results. Experimentation and statistical analysis were performed to compare the classical conventional agitator with the latest lab equipment such as a nano mill, and it was concluded that the nano mill performs better on average than the conventional agitator in the preparation of paint formulations. Hence, the sample of paint formulations was prepared on a nano mill and tested in the laboratory using advanced available technology for the analysis and comparison of paint properties to determine the best paint formulation. The results were analyzed using the Analysis of Variance (ANOVA) technique, and it was concluded that the newly developed paint has the highest dirt resistance on average. The final selected formula, No. 50 (the newly developed paint), was compared with the three best conventional paints available in the Pakistan market in a natural environment for a period of almost one year. A regression model was also constructed to study the effect of environmental factors like time, temperature, and humidity on the dirt resistance of paints. It was found that the newly developed paint formulation is the most environmentally friendly. It performs equally well as one conventional paint and has higher dirt resistance than two other conventional paint formulations containing harmful chemicals. The regression model of dirt resistance involving variables including time, temperature, and humidity shows that these factors significantly affect the dirt resistance of a given paint at a 5% level of significance. For a given paint, 95.34% of the variation in the dirt resistance is due to and explained by the given factors. The regression model is useful for predicting the average dirt resistance of a given paint with a certain level of confidence. The project exemplifies the work of applied research from conceptualization to successful commercialization in the paint industry.

Evaluation of the Characteristics and Coating Film Structure of Polymer/Ceramic Pressure-Sensitive Paint

Polymer/ceramic pressure-sensitive paint (PC-PSP), which incorporates a high percentage of particles in the binder layer, is proposed in order to improve the characteristics of PSP. The procedure for embedding particles into the binder layer was modified. In the conventional procedure, dye is adsorbed onto a polymer/ceramic coating film (denoted herein as a dye-adsorbed (D-adsorbed) PSP). In the new procedure, the mixture of a dye and particles is adsorbed onto a polymer coating film (denoted herein as the particle/dye-adsorbed (PD-adsorbed) PSP). The effect of particle mass content on PSP characteristics was investigated. In addition, the effect of solvent on PSP characteristics and film structure were evaluated for the PD-adsorbed PSP. As a result, the difference in the PSP characteristics between the two types of PSP was clarified. Although surface roughness and time response increase with increased mass content of particles for both D- and PD-adsorbed PSPs, the critical pigment volume concentration (CPVC) for the PD-adsorbed PSP is smaller than that of the D-adsorbed PSP (88 wt% and 93 wt%, respectively). The PD-adsorbed PSP has a higher frequency response comparing with the D-adsorbed PSP while maintaining the same surface roughness. Observation by scanning electron microscope showed that the CPVC of the PC-PSP is governed primarily by surface structure. The coating film structure can be roughly classified into two states depending on the particle mass content. One is a state in which the coating film consisted of two layers: a lower particle-rich layer and an upper polymer-rich layer. This type of structure was observed in the PD-adsorbed PSP as well as in the D-adsorbed PSP. In the other state, polymer and particles are homogeneously distributed in the film, and pores are formed. This difference in the coating structure results in a change in the time response.

Thermal insulation coating based on water-based polymer dispersion

For Russia, due to its long winter period, improvement of thermal insulation properties of envelope structures by applying thermal insulation paint and varnish coating to its inner surface is considered perspective. Thermal insulation properties of such coatings are provided by adding aluminosilicate microspheres and aluminum pigment to their composition. This study was focused on defining the effect of hollow aluminosilicate microspheres and aluminum pigment on the paint thermal insulation coating based on water-based polymer dispersion and on its optimum filling ratio. The optimum filling ratio was determined using the method of critical pigment volume concentration (CPVC). The optimum filling ratio was found equal to 55%.