Types and selection of paint color paste

Types and selection of paint color paste

Traditional pigments are usually supplied in the state of fine powder. The advantages are strong versatility, good stability, and convenient transportation. There is a lot of dust during use, which pollutes the environment and makes color matching inconvenient.

Paint color paste is a kind of colorant used for color mixing of paint, and it is a kind of pigment preparation. Powder pigment, solvent (water or organic solvent), resin, pigment dispersant and various functional stabilizers are processed through strong mechanical compounding, which has good dispersion and stability, flowability and good compatibility with paint wait.

Coating color paste is divided into water-based color paste, solvent-based color paste and water-oil dual-purpose color paste. Water-based color paste is a pigment concentrate with water as the dispersion medium. It uses dispersants, wetting agents, stabilizers and other functional agents to fully wet and disperse the pigments, so as to optimize the application performance of the pigments and stabilize the system. Due to the good dispersion performance of water-based color paste, it is more convenient to use than powder pigments, and will not cause dust pollution. Oil-based color paste will release a large amount of toxic solvents, which reduces environmental pollution. The use of water-based color paste, that is, color paste can Effectively solve the pollution of dust and sewage, easy to use, convenient for color matching, and can improve work efficiency, improve the application performance of pigments, such as improving color development, effectively preventing floating and blooming, etc. Therefore, it is widely used in various industries such as architectural coatings and toys.

Solvent-based color paste is a pigment paste with organic solvent and resin as the dispersion medium, and the color strength and rheology are strictly controlled. It is composed of pigments, oleoresins, pigment dispersants, stabilizers, cosolvents and functional additives. The key to choosing a solvent-based colorant is not only the compatibility between the colorant and the paint, but more importantly, the degree of negative impact on the performance of the paint after adding the colorant, especially for high-end industrial paints. There are many differences between the solvent and water used in solvent-based colorants, such as volatility, flammability, and different toxicity of different solvents, which are dangerous goods. Therefore, the production, sales, and transportation of solvent-based colorants require corresponding regulations. qualifications.

Water-oil dual-purpose color paste refers to the color paste that can be used for both water-based paint coloring and paint (solvent-based paint) coloring. Technically, it is not only necessary to solve the compatibility and dispersibility of colorants with water-based paints and solvent-based paints, but also to solve the dilution of colorants in water and other organic solvents. The development of this kind of color paste is more difficult. Therefore, the water-oil dual-purpose color paste refers to the pigment paste used for neutralizing some water-soluble paints and coloring some weakly polar oil-based paints in principle.

Before purchasing paint color paste, you should understand the relevant indicators and shelf life of paint color paste. Light resistance, weather resistance, color paste fineness, and storage stability are all ways to judge the quality of color paste. The color paste produced by the first-class technology can still maintain very good fluidity even after the warranty period, without sedimentation and delamination. Some inferior products have become very thick and have no fluidity for a long time before the product expires, so the shelf life of such color paste is very short. In addition, different color paste products have different shelf life. Due to the coating of fluorescent resin, the shelf life of fluorescent color paste will be shorter than that of general water-based color paste. For some special color pastes, the stability will be shortened due to technical difficulties. Open the paint color paste packaging barrel before use, and carefully check whether the color paste is agglomerated, or whether there is precipitation at the bottom. When you see that the color paste is delaminated and has no fluidity, you should contact the color paste manufacturer or distributor in time, and do not use it at will to avoid loss.

Taking paints for interior and exterior walls as an example, the exterior walls of buildings are exposed to the sun, rain, and strong ultraviolet light all year round, and some pigments will fade, turn yellow, and powder. When selecting color paste for exterior wall paint, it is necessary to choose paint color paste with better weather resistance and light resistance. General exterior wall paint colorants usually use phthalocyanine series and inorganic iron oxide colorants. The color paste of iron oxide series is dark in color and not bright enough, but it has good weather resistance and is very cheap. It is widely used in exterior wall coatings.It is widely used. Some organic pigment pastes with better performance can also be used in exterior wall coatings, the colors are bright and bright, and the weather resistance and light resistance performance can also meet the use requirements. But the price of these color pastes is relatively high. The interior wall water-based paint is basically not affected by the external climate. In terms of fastness, the color paste of the interior wall paint is not as strict as the color paste of the exterior wall paint, but the requirements for color safety and environmental protection of the paint are much higher than those of the exterior wall paint. many. The interior wall paint colorant should not only keep the color of the wall from fading and not yellowing when living in the indoor environment, but also ensure the safety of the human body. The color paste must be selected as harmless, non-toxic and zero VOC. When choosing a suitable water-based color paste, the architectural coatings for interior and exterior walls are simply: more color pastes for interior wall coatings require a variety of colors, high environmental protection and safety, and can meet individual needs; exterior wall coatings require weather resistance The sun is good, the price is cheap and affordable, and some of them meet the special performance requirements.