Coating technology: raw material selection mechanism of antibacterial, deodorizing and antistatic waterborne epoxy floor coating

Core tips: 1 Resin selection The waterborne epoxy floor coating is mainly composed of two components: hydrophobic epoxy resin and hydrophilic amine curing agent Waterborne epoxy floor coatings can be divided into two types: the system consisting of a relatively low molecular weight liquid epoxy resin or its emulsion and waterborne amine curing agent is called I type, and the system consisting of solid epoxy emulsion with relatively high molecular weight and waterborne amine curing agent is called II type The waterborne epoxy floor coating prepared in this study belongs to type I, and the liquid bisphenol-A epoxy resin is selected as the epoxy resin The epoxy value of epoxy resin E51 is moderate, and the cured products are Paint knowledge how about Akzo Nobel Powder Coating Recommended introduction: powder coating is a kind of coating with different form from general coating, which is in powder form It is a new type of coating, because of its own advantages and more and more known by people Let's introduce Akzo Nobel Powder coating Akzo Nobel Powder coating is a cost-effective coating solution, which can be applied to different kinds of products After the treatment of static electricity and fire baking, a tough and durable coating surface will be formed, with the least impact on the environment Since the introduction of this technology, powder coating has been able to continue to maintain the Coating home news: 1 Selection of resin water-based epoxy floor coating mainly consists of two components, namely hydrophobic epoxy resin and hydrophilic amine curing agent Waterborne epoxy floor coatings can be divided into two types: the system consisting of a relatively low molecular weight liquid epoxy resin or its emulsion and waterborne amine curing agent is called I type, and the system consisting of solid epoxy emulsion with relatively high molecular weight and waterborne amine curing agent is called II type The waterborne epoxy floor coating prepared in this study belongs to type I, and the liquid bisphenol-A epoxy resin is selected as the epoxy resin The epoxy value of epoxy resin E51 is moderate, and the cured product has high crosslinking density, good compactness and strong corrosion resistance E51 epoxy resin has low functionality (n = 0 ~ 1), low hydroxyl content and good water resistance 2 The selection of diluent the active diluent used for bisphenol A epoxy resin is usually aliphatic glycidyl ether epoxy resin, which can react with curing agent to form epoxy curing compound In order to reduce the viscosity of liquid epoxy resin E51, improve its solubility with water-based amine curing agent, enhance the emulsifying effect of water-based curing agent on the resin, and at the same time do not reduce the comprehensive performance of the cured epoxy resin, appropriate diluent should be added The requirements for diluent are: ① low viscosity; ② high epoxy value; ③ good compatibility with epoxy resin; ④ good hydrophilicity 1,4-butanediol diglycidyl ether has the lowest viscosity, so it is selected The viscosity of E51 can be reduced from 1500 MPa · s to about 600 MPa · s when the dosage is 10% ~ 15% of E51 In order to improve the compatibility of epoxy resin E51 with water-based amine curing agent and reduce the difference of solubility parameters between the two components, a small amount of latent cosolvent should be added to component A Because when the two components of a and B are mixed and solidified, the hydrophilic curing agent enters the surface of the epoxy resin from the water phase to the dispersed phase, making the concentration of the curing agent of the epoxy resin surface higher and quickly solidified into a hard shell, which will prevent the particles from forming a film, make the resin in the paint film cure unevenly, thus reducing the performance of the film Under the joint action of diluent and cosolvent, the viscosity and glass transition temperature of the resin can be effectively reduced, the compatibility and compatibility of the resin and the curing agent can be improved, and the wettability, permeability and diffusion of the curing agent to the resin can be improved, the resin can be cured uniformly, and the film performance can be improved The results show that TPMS from Dow Chemical Company is better, and the amount of TPMS is about 3% of epoxy resin 3 Selection of curing agent the curing agent used in waterborne epoxy floor coating is water-soluble amine or amine water dispersion At present, water-soluble amine is widely used For the selection of water-soluble amine curing agent, not only its reaction activity, but also its compatibility, dispersing emulsification and toxicity with epoxy resin should be considered, especially the small molecule amine compound should be used with caution because it is volatile and toxic Therefore, polyamide or amine adduct is often made as curing agent in order to improve the quality of amine and reduce toxicity The miscibility of polyamide and epoxy resin is not good and there is induction period, which can be solved by polyamide adduct Water soluble polyamide adduct curing agent is a kind of water-soluble system which has the function of curing agent and emulsifier by introducing the surface active molecular segments into the curing agent The curing process of waterborne epoxy coating is a reaction and diffusion control process, including water evaporation, particle coalescence, curing agent diffusion and curing crosslinking reaction The curing rate of water-soluble polyamide adduct to epoxy resin E51 is slow, which can make the curing material uniform; its reaction activity is moderate, which can make the comprehensive performance of epoxy resin cured product excellent; its compatibility with epoxy resin system is good, which is conducive to the diffusion of curing agent molecules to the inside of epoxy resin particles and complete curing; its glass transition temperature is low, which can weaken or avoid the shape of epoxy resin It has good wettability and can be cured by draining water, so that it can be cured to form film on wet base surface Its system is stable without consideration of high-speed dispersion, grinding and demulsification Therefore, water soluble polyamide adduct was selected as curing agent in this study 4 The selection of pigments and fillers is an indispensable component in waterborne epoxy floor coatings The selection principles of pigments are: low oil absorption value, low water absorption, high hardness, fine particle size, strong internal stress, good acid and alkali resistance, excellent weather resistance In general, the content of pigments and fillers in waterborne epoxy coating is 30% ~ 38%, while that of waterborne floor coating must ensure that the coating has appropriate air permeability, so it is necessary to increase the content of pigments and fillers properly on the premise of keeping the film-forming substance unchanged In order not to reduce the water resistance and corrosion resistance of the coating obviously, it is an effective method to select the ultra-fine pigments and fillers with good chemical resistance and add the adhesion promoter 5 Functional additive (1) antistatic agent Most polymer materials are easy to generate static charge accumulation One of the effective solutions is to use conductive coating to give the surface conductivity of the coating At present, all the antistatic coatings are additive conductive coatings The additives are conductive fillers and surfactants In this waterborne epoxy floor coating, polyaniline doped conductive polymer is selected as antistatic filler Polyaniline doped by dodecyl sulfonate has excellent conductivity and corrosion resistance It is dispersed in the cured epoxy resin as a substitute of inorganic conductive filler When the doping amount of polyaniline reaches 5%, the resistivity of the coating can reach 107 Ω· cm, which can fully meet the requirements of the standard of antistatic coating, and the effect is long, at the same time, it can improve the chemical corrosion resistance of the coating (2) Anions - antimicrobial additives Anionic antibacterial additive is a functional material combining anionic generation material and inorganic antibacterial material Anionic generation material is the only naturally charged high-quality polar material in nature Under the excitation of no light source, it naturally forms a permanent micro electric field Through the weak electrolysis of its electrode on air and water, hydroxyl anion is produced Through electric neutralization, chemical reaction and physical adsorption, hydroxyl anion can decompose and remove formaldehyde, benzene, ammonia and other harmful gases in the air, at the same time, it can inhibit the survival of mould, remove peculiar smell, and clean the air 6 The selection of additives for waterborne epoxy floor coating requires the use of various additives to adjust the viscosity or surface tension of the coating, especially the selection of wetting and dispersing agents In order to improve the wettability and dispersibility of pigments and fillers, improve the stability and suspension of pigments and fillers through the mutual repulsion of negative charges, reduce the precipitation and agglomeration, weaken the cohesion between pigment particles, avoid floating color and blooming, self emulsifying acetylene glycol non-ionic surfactant SURFYNOL is selected Stable dispersion system can be obtained by combining se-f with fa182 dispersant of shengwo company In order to adjust the viscosity of water-based epoxy floor coating, organic modified clay thickener was selected to adjust the viscosity The effect of vt-819 thickener was ideal The defoamer should be long-term and high-efficiency non silicon defoamer, such as SURFYNOL df-75 defoamer 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,