Pigments and fillers are important components of paints. According to the requirements of paints, the types and quantities of pigments and fillers are different. There are single pigments and fillers, and two or more kinds of composites. Dozens of percent, sometimes as high as 60%. These pigments and fillers can not only ensure good hiding power and rich colors of the paint, but also give various special functions to the coating film and construction. As pigments and fillers for coatings, performance indicators such as dispersibility, whiteness, color specified . illustrate.
1. Pigments and fillers
Pigment is a kind of colored fine granular substance, which is insoluble in the dispersion medium, and is a kind of inorganic or organic substance that shows its color with "particles" . The particle size range of pigments is usually between 30nm - l00µm. The color, hiding power, tinting power and other characteristics of the pigment are greatly related to its dispersion state in the medium (existing state of the pigment particles in the medium) . There are many similarities and differences between organic pigments and dyes in pigments. For example, both have coloring ability, and some varieties have the same color structure. The most fundamental difference is that "dye" can be dissolved in an appropriate solvent when used.
Filler is a kind of fine granular substance with the main purpose of " filling " in the medium , which is insoluble in the dispersion medium, and is also called extender pigment. The appearance of the filler is mostly white or light gray, and its hiding power and decolorizing power are very low in the medium. Adding fillers to the medium can effectively change the non-color physical and chemical properties in the medium.
2. The role of pigments and fillers
1. The role of pigments
Pigments are colorants in the production of paints and paints. In addition to providing color decoration for paint films, pigments can also improve the physical and chemical properties of paints, such as hiding, light resistance, weather resistance, temperature resistance, chemical resistance, Gloss and mechanical strength etc. Functional pigments can impart special properties to coatings, such as special decorative effects (metallic texture, pearl luster, luminous, fluorescent, etc.), anti-corrosion, fire prevention, conductivity, anti-static, temperature display, etc.
2. The role of fillers
Fillers have two main functions in coatings, one is to " fill " and reduce costs; the other is to change . Modern paint technology pays more attention to the second role of fillers. For example, by choosing different types and numbers of fillers, the storage performance and construction performance of the paint can be effectively improved, and the mechanical strength, abrasion resistance, and water resistance of the paint film can be improved. , anti-ultraviolet, heat insulation and anti-cracking properties. Compared with pigments, most fillers have the advantages of low cost, low oil absorption and easy dispersion.
See below for a detailed comparison:
coloring pigment
1. Give the paint and paint film many colors, improve the decorative and protective properties of the paint film; (color matching)
2. The hiding power and vividness of the paint
3. Color resistance (light resistance, weather resistance, acid resistance, alkali resistance, solvent resistance, temperature resistance, etc.)
4. Provide safety color (safety sign)
Antirust Pigment
Prevent chemical or electrochemical corrosion on the metal surface (with physical anti-rust and chemical anti-rust), such as inactive aluminum powder, graphite, iron oxide red; active
Non-toxic zinc oxide, zinc powder, basic lead chromate, red lead, zinc chromate yellow, etc.
Special Function Pigments
Give the coating special functional effects, such as pearlescent pigments to make the paint film have a gorgeous pearl luster effect; metallic pigments to make the paint film have a metallic glitter effect; nano-pigments to make the paint film anti-ultraviolet, mildew-proof, water-resistant and super weather-resistant and temperature-resistant. ; There are also temperature indicating pigments, luminous pigments, fluorescent pigments,
Color-changing pigments, etc. can make the paint film obtain the corresponding effect
filler
1. Improve the mechanical strength of paint and paint film
2. Increase the solid content, reduce the use of resin and solvent, and reduce the cost
3. Endow the paint with good fluidity, can-opening effect and construction performance, and increase the thickness of the paint film
4. Participate in film formation, provide partial coverage, wear resistance, anti-ultraviolet light, and prolong the service life of the paint film
5. Special functions, such as UV shielding, heat resistance, and minimal grouping
6. Improve other properties, such as thickeners, rheological agents, antistatic agents, UV stabilizers, etc.
