Colorful paint is widely used in decoration engineering because of its rich colors, convenient construction, strong three-dimensional decorative effect, low price, and convenient renovation and renewal after one spraying. Colorful paints are different from traditional architectural paints, such as acrylic paints, styrene-acrylic paints, etc. These paints are single-phase, single-color uniform paint products, and the product quality is relatively stable, while colorful paints are multi-color, multi-phase particles mixed Coexistence, the stability of product quality may have many problems.
1. The floating layer of colorful paint. The floating layer of the colorful paint means that some particles of the colorful paint float on the surface of the protective glue liquid in the finished product barrel, covering the entire liquid surface in the barrel and having a certain thickness. These particles float on the surface of the protective glue solution and are directly in contact with the air, so that a layer of protective glue film wrapped on the surface of the particles gradually becomes thinner due to evaporation, until it is damaged and lost, which seriously affects the uniformity, construction and decoration of the coating. sex. Multi-color paint is a stable suspension composed of various colors of enamel and protective glue aqueous solution, which requires the two phases to be as close to or even equal in gravity as possible. If the specific gravity of the enamel particles is less than that of the protective glue, the enamel particles float up to form a floating layer, causing the particles to fuse with each other and form a skin; or the specific gravity of the enamel particles is greater than that of the protective glue. After a period of time, the enamel particles settle at the bottom of the container and accumulate densely due to gravity. Gather and fuse, destroying the shape of the desired particle. Therefore, the specific gravity of enamel, protective glue and the difference between them are the main factors affecting the floating layer phenomenon.
2. Bleeding of colorful paint and turbidity of dispersion medium. The dispersion medium of colorful paint obviously shows the same color as the color particles, or the dispersion medium becomes a milky turbid liquid, and in serious cases, many fine flakes appear in the turbid liquid. The main reason for this phenomenon is that the gel protective film on the surface of the colored particles is not strong enough and too fragile. The pigments, fillers, and additives inside the colored particles continue to penetrate through the fragile protective film, making the dispersion medium gradually colored. The color of the grains, resulting in turbidity. The main reason for the insufficient strength and fragility of the protective film is that the concentration of the insolvent in the dispersion medium is insufficient.
3. The dispersing medium flocculates into lumps and clusters, forming a cotton-like colloid that is not easy to disperse, and wraps all the color particles in it. And the longer the storage time, the more serious the problem. The main reason for this phenomenon is that the pH of the dispersed phase and the dispersion medium is not suitable, especially the high alkalinity of the dispersion medium, which causes the polymer compounds in the dispersion medium to gradually condense into large and small particles. Small clumps, some in the form of cotton flocs, and some in the form of net-like agglomerates.
4. The color particles are dull and lustrous. Most cellulose-based thickeners, defoamers, and some types of pigments have a matting effect. Often, white color particles have better luster, while other colors of color particles have poorer luster. The reason is that white color particles generally use neutral High-quality titanium dioxide is used as a pigment and filler. The performance of titanium dioxide is stable, so the gloss is better, and some types of pigments are strongly alkaline or acidic, which can easily cause the color particles to lose their luster.
