Preparation of epoxy-colored sand floor coatings

China Coatings Online News
Li Shunxi 1, Ma Xiaofang 2 (1. Northwest Normal University School of Chemical and Chemical Sciences, Lanzhou 730070; 2. Northwest Yongxin Group Co., Ltd., Lanzhou 730046)
Abstract: Introduction to the preparation of epoxy sand flooring coatings, epoxy resin, epoxy reactive thinners, additives, color quartz sand and solidification agent selection discussed. Epoxy sand decorative floor with colorful patterns, decorative effect image vivid, wear-resistant, pressure-resistant, chemical corrosion-resistant, temperature-resistant change performance, but also with anti-slip, fire, waterproof and other characteristics.
key words: colored sand flooring; high-speed mixing; solvent-free; epoxy
in the classification number: TQ630.7 Document identification code: A article number: 1006-2556 (201) 4) 11-0073-04
0. Foreword
epoxy resin is widely used in the decoration of building floors, thanks to the rapid development of solvent-free liquid epoxy resin, as well as construction technology and complete construction equipment. Up to now, epoxy flooring products are complete, solvent-based epoxy wear-resistant flooring coatings, water-based epoxy flooring coatings, outdoor weather-resistant flooring coatings, epoxy self-leveling flooring coatings and anti-static epoxy flooring coatings, etc., to meet the requirements of various industries for clean, hygienic, dust-proof, wear-resistant, pressure-resistant, chemical corrosion-resistant, water-resistant, waterproof, anti-static and other functions. In recent years, epoxy decorative flooring in Europe and the United States and other developed countries are very popular, known as "color sand seamless hard carpet", epoxy sand decorative flooring is a color quartz sand and special epoxy resin composed of seamless integration of a new composite decorative floor, through one or more different colors of color quartz sand free matching, forming a colorful decorative pattern. Colored sand used in epoxy-colored sand flooring is generally natural colored sand, natural colored sand is the use of natural colored marble, granite and other sand grains, natural color, never change color, good resistance to pressure, construction close to the effect of natural stone. Epoxy-colored sand decorative flooring has the advantages of elegant decorative texture, wear resistance, pressure resistance, chemical corrosion resistance, temperature difference resistance, anti-slip, fire prevention, waterproofing and so on. Epoxy sand decorative flooring performance is stable and reliable, decorative effect is beautiful, a wide range of use, can be used in offices, shopping malls, medicine, subway, electronics, home furnishings and other places ping construction. The construction process of epoxy-colored sand flooring is mainly through scraping colored mortar, for large areas of construction is mainly taken by polishing machine flat, and then properly polished, and finally coated with transparent varnish.
1. Test part
1.1 Raw materials
epoxy E-51: industrial grade, Blue Star chemical new materials factory Wuxi resin plant;
1.2 Paint formula (see Table 1)
Note: m (preparation paint for color mortar): m (curing agent): m (colored sand) : 2:1: (4 to 6).
1.3 Production process
in the clean ingredient basin to add the formula amount of epoxy resin, in turn under stirring to add the formula amount of epoxy reactive thinner, dispersant, deboist and leveling agent, stirring well, sampling inspection of this product, qualified after filtration packaging, this production process is high-speed mixing method, simple operation, easy to clean.
1.4 Test results (see Table 2)
2. Results and discussion of
2.1 resin selection
Epoxy sand floor coating after coating in order to make the color of color sand can be fully displayed, increase texture and beauty, to ensure the excellent performance of the floor and environmental requirements, so should be used transparent solvent-free, low-viscosity epoxy resin. When mixing colored quartz sand, low-viscosity epoxy resin and colored sand are easier to mix evenly, so that the resin mortar does not bond to each other and is easy to coat, so epoxy resin must be low-viscosity. Low viscosity epoxy resin in the coating film process can make color sand more easily precipitated to the lower layer of the coating film, and defocusing and leveling effect is better, so according to these characteristics finally selected E-51. E-51 resin is a liquid epoxy resin type BPA, the resin molecule has a high polarity and not easy to hydrolysate the fat family hydroxyl bonds and ether bonds, so in a humid state on the concrete substrate has a high adhesion, and high chemical resistance. Bisphenol A epoxy resin has a rigid benzene core and flexible hydrocarbon chain alternate arrangement structure, so that the coating film has a better physical and mechanical properties. Therefore, the choice of BPA epoxy resin E-51 veritable, the resulting coating film has a high mucous relay, strong mechanical strength, chemical corrosion resistance and good electrical insulation.
2.2 Choice of Active Thinners
The use of active thinners is a very effective way to reduce viscosity, the active thinner is a colorless transparent liquid with low viscosity , which can reduce the viscosity of the coating and can play a dilution effect. The composition of the active thinner contains the official energy group of epoxy, which can react with the amine curing agent to become a component of the coating film, so that the appropriate amount of epoxy reactive diluent is added to the paint, which can not only reduce the viscosity of the coating, but also does not increase the volatile organic matter (VOC) content of the coating. Foreign epoxy reactive thinners generally use C12 to C14 shrinking glyceline ether, acrylic shrinkage glyceline ether, can provide better mirror effect. At present, most domestic manufacturers use BGE and other shrinking glycelycee ether, so the test is selected is 501A butyl shrinkage glycether. The viscosity of 501A butyl shrinkage glycelor ether is low, and the dilution effect and solubility of E-51 epoxy resin are good.
2.3 additive selection
epoxy-colored sand floor for the coating of the requirements are very high, colored sand floor is mainly thick coating-based, the requirements of the coating film has a good leveling performance, while requiring the rapid discharge of bubbles in the coating film and the coating surface does not leave pits, shrink holes or pinholes and other defects, so the choice and dosage of additives is a critical factor.
2.3.1 Wetting Dispersant
In order for the colored sand floor coating to be wetting the substrate, an excellent wetting dispersant with excellent epoxy system compatible is required. If the dispersant is not selected properly or the dispersant is used too little, the dispersion system is unstable. When there are too many dispersants in epoxy floor coating, the excess dispersant causes the surface pressure of the coating to drop seriously, and makes the dispersion system unstable, resulting in the surface effect of the floor coating film is not good, the gloss is low, and the mechanical performance of the floor is reduced. When there are too few dispersants in epoxy floor coating, the wetting properties of the substrate are not available, and after testing, the final selection is to add the polymer-type wetting dispersant BYK-142, which is 0.3% to 1.0% (mass fraction).
2.3.2 de-foaming agent
epoxy-colored sand floor in the construction process to add a certain ratio of color quartz sand, after stirring, dispersion will often bring in a certain amount of air, because epoxy-colored sand flooring paint is thick coating type, bubbles are not easy to escape, so it is necessary to add a certain amount of anti-foaming agent in the coating to eliminate the air caused by the air. After the test selected Bick's desobbist BYK-066N, after adding a very good de-foaming effect, after the construction of the appearance of good results, smooth surface.
2.3.3 leveling agent
epoxy sand floor coating if the leveling of the coating is not good, then the coating surface is uneven, there are obvious scratches, drying process is also prone to shrink holes, pinholes and other ills, damage its protection and aesthetic performance. Therefore, the leveling of coatings is a very important performance indicator. Improved leveling usually improves the leveling performance of coatings by improving the surface pressure between the coating and the substrate, giving the coating and substrate better wetting and forming a single molecular layer on the surface of the coating film, providing a flat surface pressure. There are three commonly used leveling agents: polymer leveling agents, silicone and fluorocarbon leveling agents. The silicone leveling agent BYK-320 was selected, the addition amount was 0.3% to 1.0% (mass fraction), and the use of leveling agent made the formation of the coating film surface flat, smooth and uniform.
2.4 Colored Sand Selection
Colored sand in epoxy-colored sand floor paint refers to colored quartz sand, which can give the floor a colorful pattern. Epoxy-colored sand flooring paint used to be a seamless, integrated decorative flooring made of artificially dyed colored sand and epoxy resin. Because of the color sand tone dull, very easy to change color, poor heat and sun resistance, and sometimes pressure will also appear internal color change, and the place without pressure has a clear demarcation, put color sand exposed to the sun, can be clearly seen with the uncolored sand there is a color difference; Stained color sand in a large area of sand construction in serious marks, the construction speed is required, can not stop work rest, dyed color sand because the package of a layer of resin is more brittle, poor pressure resistance, so epoxy sand floor paint no longer use dyed color sand but with natural color sand. Natural color sand is the use of natural marble, granite and other sand grains, natural color, never change color, good pressure resistance, construction close to the effect of natural stone, and the cost of sand is lower than dyed color sand. High-quality color natural quartz sand, its color, particle roundness, particle size ratio and chemical resistance is good, stable and reliable quality. Round or spherical particle-like quartz sand, in the construction process between particles free to slide, so that the sand particles can be as "the closest accumulation", so that the epoxy sand layer is fully dense, can save the amount of resin on the surface, reduce costs, and ensure excellent pressure resistance and wear resistance of the floor. Therefore, a round or spherical colored quartz sand with a particle size range of 0.3 to 3 mm is used.
2.5 Curing agent selection
curing agent should be the choice of containing anti-water spots and anti-whitening ingredients, generally choose two or more curing agents for compounding, in order to make the appearance of the coating film to achieve the desired mirror effect, generally the choice of curing speed is relatively fast and slower curing agent compounding, in order to achieve a moderate curing speed. The polyether amine-modified curing agent and the lipoline-modified curing agent were selected for testing. Polyether amine modified curing agent, low temperature curing speed is relatively slow, polyetheramine easy to absorb moisture, water resistance is not good, especially to do the ground is relatively humid, after moisture absorption on the performance of the coating film has an impact. Polyetheramine is relatively soft and elastic, but the floor coating has higher requirements for wear resistance and flexibility. So in the end, the modified lipid cyclamine curing agent was chosen.
3. Colored sand flooring coating effect
the effect of colored sand flooring paint prepared by the test is shown in Figure 1.
4 conclusion
test preparation of epoxy-colored sand floor coating is a high solid, solvent-free environment-friendly, at the same time has high decorative properties of a new type of floor coating. The active diluent 501A used because the molecule contains ether bonds and epoxy base, can be infinitely mixed with epoxy resin, dilution epoxy resin effect is good, curing when participating in the curing reaction, the formation of an average system, so it will not cause pollution to the environment, and the active thinner 501A itself very low viscosity, so it is the most commonly used epoxy resin active thinner. Since the thinner can react with the curing agent, the amount of curing agent needs to be increased accordingly when used. Production is using high-speed mixing method, this method is convenient to produce, the production speed is fast, save the station.
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