Coating knowledge: how to choose fillers to make better emulsion paint

The key points are as follows: choosing the type and specification of Fillers Reasonably in latex paint can improve the quality of paint greatly, if not, it will bring unnecessary trouble 1 Select different varieties according to the application scope of coating Emulsion paint is divided into interior wall paint and exterior wall paint Generally, fillers with good weather resistance and not easy to be powdered are selected in the exterior wall paint Sericite, barium sulfate, wollastonite, calcined kaolin, etc are recommended, and light calcium is not generally used; products with high whiteness such as heavy calcium, light calcium, talcum powder, kaolin, etc are recommended in the exterior wall paint, and ultra-fine powder is used at the same time Table 1 shows the product properties of several conventional fillers Shenyang steel structure fireproof coating construction expert punde Building Fire Engineering Co., Ltd Recommended introduction: since its establishment, Shenyang punde Construction Fire Engineering Co., Ltd has cultivated a group of professional construction teams with excellent equipment, rich experience and serious responsibility with advanced and scientific management methods and strict engineering quality assurance and after-sales service system It has undertaken a number of fire system installation projects, which has been praised by customers Every idea and special requirement of you will be fully considered by us and fully realized in the construction technology, which will become the cornerstone of our successful long-term development We are looking forward to your invitation, to provide you with quality services and high-quality technical support! All construction coatings have passed ISO9001 Paint Home News: in latex paint in a reasonable choice of filler varieties and specifications can greatly improve the quality of paint, if the choice is not appropriate, it will bring unnecessary trouble 1 According to the application scope of the coating, different types of emulsion paint are divided into interior wall coating and exterior wall coating Generally, the filler with good weather resistance and not easy to be powdered is selected in the exterior wall coating Sericite, barium sulfate, wollastonite, calcined kaolin, etc are recommended, and light calcium is not generally used The products with high whiteness such as heavy calcium, light calcium, talcum powder, kaolin are recommended in the exterior wall coating, At the same time, ultrafine powder is used Table 1 shows the product performance comparison of several conventional fillers 2 According to the variety of fillers used, fillers with different fineness, such as heavy calcium, barium sulfate, talcum powder, calcined kaolin, etc., are selected for use in the coating On the one hand, they play the role of physical filling, on the other hand, they have certain dry covering power It is generally recommended to use ultra-fine products, because fillers have synergistic effect on the covering power of titanium dioxide, when the particle size of the powder reaches the microminiaturization level, Basically, when the particle size of the titanium dioxide pigment is close to that of the matched titanium dioxide pigment, the covering effect of titanium dioxide can be improved, and the strength and water resistance of the paint film can be improved at the same time Wollastonite and sericite are used to improve the strength, weatherability and water resistance of the paint film It is generally recommended to use products of 800 mesh or so For example, when considering the effect of the paint film, products of 1250 mesh or so can be used Products of more than 2000 mesh are generally not recommended 3 According to CPVC concentration requirements, choose different critical pigment volume concentration (CPVC) of fillers, which refers to the pigment volume concentration when the base material just covers the surface of pigment particles and fills the accumulation space of pigment particles The higher the fineness of fillers, the larger the specific surface area and the higher the oil absorption value, the smaller CPVC will be Generally, the PVC of latex paint formula is not more than CPVC, otherwise it will affect many physical properties of paint film With the increasingly fierce market competition of latex paint, in order to reduce costs and enhance competitive advantage, the development of high PVC latex paint has become an important research topic for latex paint manufacturers The CPVC value of two latex paint formulations with the same PVC value is not the same due to different raw materials and proportions Therefore, in order to make latex paint have high PVC value and its quality meet the national standard, the key is to make latex paint have high CPVC, so as to minimize the gap between PVC and CPVC value In the design of paint formulation, ultra-fine fillers are used for high-performance latex paint, while fillers with relatively coarse particle size and low oil absorption value, such as heavy calcium and barite, are selected for low-grade latex paint 4 The index control of fillers there are many kinds and specifications of fillers, which are quite confusing Only by selecting high-quality and stable products can the quality of latex coating be guaranteed The indexes to be considered in the use of fillers for emulsion paint are: product purity, whiteness, particle size, 325 mesh screen residue, pH value and oil absorption Purity is one of the most important indexes of products, and functional filler is particularly important High quality talcum powder can improve the construction performance and leveling of emulsion paint; high-purity wollastonite can greatly improve the strength of the paint film; sericite flakes are stacked in the film layer by layer to improve the strength and water resistance of the paint film, with unique UV shielding function and improve the weather resistance of the paint, etc For talcum powder and wollastonite filler, the SiO2 index is used to determine, and the higher the SiO2 content, the purer the product; for sericite, kaolin and other aluminum silicate filler, the SiO2 and Al2O3 indexes are used to control; for calcium carbonate, the CaCO3 content is used to determine Whiteness is one of the basis for customers to choose fillers, especially for fillers such as heavy calcium, light calcium, kaolin, etc which use dry covering power; at the same time, the color phase of fillers should be considered, and the cyan phase is the best In the market, the grain size is generally determined by the number of mesh This method is not very scientific At the same time, some manufacturers fill the high mesh products with the low mesh number Generally, it is recommended that customers require to provide the grain size distribution map when selecting the raw material products, and it is more valuable to determine the median grain size For the selection of functional filler, we must also know the production process of the product For example, the performance of kaolin products produced by coal burning and electric burning processes is very different, and the performance of Sericite products produced by dry and wet processes is also very different When selecting fillers, the customer must strengthen the understanding of index control to the manufacturer, control the batch stability of raw materials, and at the same time, it is recommended not to change the product specifications and manufacturers at will 5 The functionalization of fillers for latex paint with the continuous improvement of the R & D level of latex paint, consumers have higher requirements for product functions The high-performance and multi-functional of latex paint has become the development trend of the paint industry For example, the interior wall latex paint is environmentally friendly, non-toxic, anti-bacterial and anti mildew; the exterior wall paint is aging resistant and self-cleaning The traditional fillers play a role of skeleton structure in the coating, but have little effect on improving the function of the coating In recent years, some latex paint manufacturers at home and abroad have begun to study some functional fillers to improve or endow the paint with new functions, and have made some achievements Due to the difference of chemical composition and crystal structure, the processing technology and application technology of functional fillers are different Through the improvement of processing technology, the characteristics of fillers can be improved or new functions can be given to latex paint It mainly represents the contribution of the flake sericite powder to the weatherability of the coating; the improvement of the storage stability of the coating by the adsorption filler; the improvement of the antibacterial and weatherability of the coating by the nano filler and the wide application of some new functional fillers The flake sericite powder has the crystal polarization effect and the light interference effect of crystal water between layers, which has a strong absorption and shielding effect on ultraviolet rays In the latex paint, the product can not only improve the mechanical properties of the coating, but also improve the anti-aging and anti UV properties of the coating, prevent cracking and delay the pulverization, and at the same time, it can maintain the color of the coating for a long time Nano filler is generally prepared by synthetic processing, or non-metallic powder processing with nano structure, such as nano calcium carbonate, nano ZnO, etc., is applied in the coating system, which can make the coating have the function of anti-bacterial and anti mildew, improve the weather resistance of the coating film, and greatly improve the comprehensive quality of the coating material 6 Conclusion: latex paint products develop rapidly, but the competition is increasingly fierce How to be invincible in the market? Quality and cost is an eternal theme The cost and quality of coatings are closely related to the choice of raw materials They should not only focus on emulsion, titanium dioxide and auxiliaries, but also strengthen the selection and control of fillers Fillers account for 20% ～ 40% of the composition of latex paint High quality and stable fillers are the guarantee for the production of high-quality products With the further study of coating technology, more and more new functional materials will be applied in the coating system Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,