Development and research progress of the hottest e

2022-08-13
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Development and research progress of environment-friendly water-based glazing oil (I)

Abstract: This paper introduces the characteristics of water-based glazing oil and the selection and function of main components in the development process, summarizes the research progress and existing problems of water-based glazing oil from two aspects of system type and curing mechanism, puts forward the best formula and main technical indicators, and discusses some applications of water-based glazing oil

key words: aqueous polish; Environmental performance; development; Research progress; Application

nowadays, environmental protection has been paid more and more attention by governments all over the world in daily life. Environmental protection has been listed in an important position in the field of packaging, publishing and printing, because now the pollution of printed matter is a very serious problem faced by the packaging industry, and most of the glazing oils used are solvent based products. Some carcinogens (solvents) remain after printing, which pose a long-term threat to human health. People strongly demand that organic solvents be gradually reduced or even eliminated. Therefore, in order to find alternative products, we must develop high-quality non organic solvent glazing oil. Water is a cheap and pollution-free residual solvent. Therefore, the development of environmental friendly water-based glazing oil has attracted great attention at home and abroad, and has a bright future

1 characteristics of water-based glazing oil

glazing oil is also called dispersion coating, which can be roughly divided into solvent type, water-based type and active dilution type. Solvent based varnish contains a large amount of organic volatile compounds (VOC), which cause serious harm to human health and environmental protection, and there are also certain fire hazards. The active diluting varnish has fast curing speed, good film-forming performance and excellent gloss, but it is difficult to control the film-forming process by adding more low molecular weight diluents in the construction, which also has certain pollution problems to the environment and constructors, and the prices of some raw materials are also high. Water based glazing oil is a water dispersive glazing paint developed on the basis of solvent based glazing oil. With water as solvent, its best advantage is that it is odorless, non-toxic and free of environmental pollution. It can fundamentally improve the production environment and promote environmental protection and labor protection. Water based glazing oil has the characteristics of good film-forming performance, high gloss, abrasion resistance, folding resistance, water resistance, heat resistance, aging resistance, economy and sanitation

2 composition of aqueous Polish

aqueous polish is mainly composed of main agent, solvent and functional additives

1) main agent. The main agent of water-based glazing oil is film-forming resin, which is the film-forming material of glazing agent. It is usually synthetic resin, which affects and dominates various physical functions in the deep layer and the glazing products of the film layer, such as some heavy-duty gear oils, such as gloss, adhesion, dryness, etc

2) solvent. The main function of solvent is to dissolve, decompose or dilute composite resins and various functional additives. Used to adjust the viscosity and dryness of glazing oil. The solvent of environment-friendly waterborne polish is water. The volatility of water is zero, its leveling performance is good, and its sources are wide. It is colorless, non-toxic, and uses the possible causes and dangers of heterotopic ossification. The transparency is better than the "green material" of pvc/eva and TPO, which cannot be compared with other solvents

3) functional additives. The function of functional additives is to improve the physical and chemical properties and processing characteristics of water-based glazing oil. There are many kinds of additives, which are generally added appropriately according to the use method of glazing oil. Use defoamer to control the bubbles of glazing oil and solve the quality defects such as fish eyes and pinholes in the use of glazing oil; Use surfactants to reduce the surface tension of aqueous solvents and improve the leveling property; Use dispersant to improve the dispersion performance of the resin, prevent dirt and improve wear resistance; Film intensifier is used to improve the adhesion between film-forming material and substrate; Use plasticizer to improve the folding resistance after glazing; Use a brightener to make the Polish glossy and transparent

3 research progress of water-based Polish

the current research status, from the system type, mainly includes water lotion dispersion type and water-soluble type; In terms of curing mechanism, there are mainly three types: volatile drying type, heat curing type and light curing type

3.1 aqueous lotion dispersed Polish

3.1.1 volatile dry aqueous lotion Polish

from the type of film-forming material, there are mainly acrylate and styrene butadiene latex

1) acrylic water lotion glazing oil

traditional acrylate aqueous lotion is prepared by single-phase polymerization. The introduction of St can improve the gloss of acrylic glazing oil and reduce the cost. Diethylaminomethacrylate MMA st terpolymer styrene acrylic lotion (tg95 ℃) developed by ooshita and yanajida is coated for 10 μ, The polishing layer is dried at 80 ℃, with wear resistance and adhesion resistance, gloss of 68%, and high adhesion (tape stripping test). With the introduction of St, the utilization rate of St in new energy vehicles reaches 30%, which reduces the weather resistance and aging resistance of the coating film on the products to a certain extent. A-ms has high gloss and weather resistance because its molecular structure does not contain oxidizable-h group, but its cost is increased. Fujiwara et al. Polymerized st80, a-msl0, mmal0, MAA latex to produce latex with particle size of 75mm and solid content of 39%, especially 75 ° reflective gloss of 70.2% after coating. Mma-a-ms-st lotion developed by Kano et al. Is calendered at 92 ℃, with a 75 ° reflection gloss of 88.6%

in order to improve the mechanical and thermal properties of thermoplastic acrylate dispersion, people use multi-step polymerization and design of polymer mi crospheres to prepare core/shell acrylate lotion. Li Liangxun, Lu Shanzhen developed core/shell St/BA waterproof latex by self seed semi continuous method. After adding coating additives, the film forming temperature is O ~ 5 ℃. Youbo et al. Developed St/BA lotion under the initiation of ammonium persulfate ferrous salt and reducing agent s, and compared the properties of lotion under thermal initiation and redox initiation. The results showed that the core/shell lotion copolymer prepared by redox initiation had a tensile strength of 5.0mpa, an elongation at break of 36%, a viscosity of 60 (coated - 4 cups, s), good leveling, transparent, bright and ductile film formation, while the lotion prepared by thermal initiation had a tensile strength of only 3.6mpa, an elongation at break of 29%, and a viscosity of 27 (coated - 4 cups, s), and a phenomenon of sagging, with opaque, yellowing and poor toughness film formation. The core/shell styrene acrylic lotion developed by Hahn and heaps can be used for product polishing

2) styrene butadiene latex polish

styrene butadiene latex for paper has the advantages of low viscosity, good adhesion, soft and moderate glazing film, smooth and bright, low cost, and was used in many countries in the early stage. However, due to the existence of unsaturated bonds in styrene butadiene latex, it is prone to yellowing and aging under the action of light and heat, and its outdoor durability is poor, which limits its further development. In practical application, carboxyl monomers and/or nitrile monomers are often copolymerized and modified for paper polishing process. This kind of polish is mainly divided into 4 kinds: styrene butadiene latex, carboxyl styrene butadiene latex, nitrile butadiene latex and carboxyl nitrile latex

thickeners are often added to the varnish on styrene butadiene latex, including ethyl hydroxyethyl cellulose, starch, rosin, rosin derivatives, etc. EA MMA polyethylene glycol (2-propenyl-4-nonyl) phenyl ether can also be used as thickeners; Stripping agents are generally fatty acid metal salts, such as aluminum phosphate; Paraffin acts as a smoothing agent and wear-resisting agent in the glazing of products; Nishikawa first coated the paper with kaolin, CaCO3, oxidized starch, SBR, epoxy resin, etc., calendering gloss 65%, and then acid salt 2.0% Al2 (SO4) 3? 18H2O coating, gloss 94.1%. The introduction of carboxyl group can increase the water retention performance, shear stability, not easy to cause scratches and stripes, and has high bonding strength and good water resistance. Yan Jinhua and Chen Kefu used nitrogen driven high-pressure capillary viscometer to study the flow law of varnish on paper based on oxidized starch and carboxyl styrene butadiene latex at high shear rate. The properties of nitrile butadiene latex and carboxyl nitrile latex are similar to those of carboxyl styrene butadiene latex, and the film strength is better

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