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CN-117380904-B - Water-based quick-drying coating for casting and preparation method thereof

CN117380904BCN 117380904 BCN117380904 BCN 117380904BCN-117380904-B

Abstract

The invention relates to a water-based quick-drying coating for casting and a preparation method thereof, wherein the water-based quick-drying coating is prepared from the following raw materials, by weight, 60-80% of refractory aggregate, 3-10% of binder, 0.5-5% of suspending agent solution, 0.2-1.0% of quick-drying auxiliary agent, 0.2-1.0% of dispersing agent, 0.1-1.0% of defoaming agent, 0.2-1.0% of water reducer and 14-25% of carrier liquid. The water-based casting coating has the characteristics of short drying time, small gas generation amount and high surface strength.

Inventors

  • LIU WEIHUA
  • LIU BAO
  • SONG LAI

Assignees

  • 沈阳工业大学

Dates

Publication Date
20260508
Application Date
20231024

Claims (7)

  1. 1. The water-based quick-drying coating for casting is characterized by being prepared from the following raw materials, by weight, 60-80% of refractory aggregate, 3-10% of binder, 0.5-5% of suspending agent solution, 0.2-1.0% of quick-drying auxiliary agent, 0.2-1.0% of dispersing agent, 0.1-1.0% of defoaming agent, 0.2-1.0% of water reducer and 14-25% of carrier liquid; The adhesive comprises an organic adhesive and an inorganic adhesive, wherein the part ratio of the organic adhesive to the inorganic adhesive is 3-4:4-8, and the organic adhesive is acrylic emulsion or modified acrylic emulsion or the combination of the two components in any proportion; The minimum film forming temperature of the acrylic emulsion is 20-60 ℃, the glass transition temperature is 20-65 ℃ and the pH value is 7-8, and the modified acrylic emulsion is modified acrylic emulsion aiming at improving the minimum film forming temperature and the glass transition temperature; the quick-drying auxiliary agent is one of propylene glycol phenyl ether, propylene glycol butyl ether, trimethylpentanediol isobutyrate monoester and trimethylolpropane diallyl ether, or the combination of two or more of the propylene glycol phenyl ether, the propylene glycol butyl ether, the trimethylpentanediol isobutyrate monoester and the trimethylolpropane diallyl ether.
  2. 2. The water-based quick-drying coating for casting according to claim 1, wherein the refractory aggregate comprises zircon powder, white corundum powder, brown corundum powder, mullite powder, high bauxite powder, quartz powder, graphite powder and ferric oxide, and two or more of the above materials are combined in any proportion.
  3. 3. The water-based quick-drying coating for casting according to claim 1, wherein the suspending agent is one of CMC, xanthan gum, polyacrylamide and sodium alginate, or a combination of two or more of them in any proportion.
  4. 4. The water-based quick-drying coating for casting according to claim 1, wherein the dispersing agent is one of polyphosphate, polyacrylate and polycarboxylate, or a combination of two or more of them in any ratio.
  5. 5. The water-based quick-drying coating for casting according to claim 1, wherein the defoaming agent is one of n-butanol, mineral oil high-efficiency defoaming agent and organosilicon modified defoaming agent, or a combination of two or more of them in any proportion.
  6. 6. The water-based quick-drying coating for casting according to claim 1, wherein the water reducing agent is one of a polycarboxylate water reducing agent, a naphthalene sulfonate water reducing agent and calcium lignosulfonate, or a combination of two or more of them in any ratio.
  7. 7. A method of preparing a water-based quick-drying coating for casting as claimed in claim 1, comprising the steps of: (1) Preparing a suspending agent aqueous solution with the concentration of 1-3%, grinding at a high speed to prepare a suspending agent solution, and standing for 24 hours for later use; (2) According to the mass percentage, 0.2-1.0% of dispersing agent, 0.2-1.0% of quick-drying auxiliary agent, 0.2-1.0% of water reducing agent, 0.5-5% of suspending agent solution in the step (1), 3-10% of binder and 14-25% of carrier liquid are accurately weighed, and dispersed for 5-10 min to prepare water-based coating liquid slurry; (3) Accurately weighing 60-80% of refractory aggregate, dry-mixing for 5-10 min, and preparing the water-based coating refractory aggregate; (4) Uniformly mixing and stirring 18.6-43% of water-based coating liquid slurry and 60-80% of refractory aggregate according to mass percentage, grinding at a high speed of 800-1200 rpm for 30-40 min, stirring at a low speed of 100-300 rpm, adding a defoaming agent of 0.1-1.0%, and eliminating bubbles; (5) And discharging and filling to obtain the water-based quick-drying coating for casting.

Description

Water-based quick-drying coating for casting and preparation method thereof Technical Field The invention relates to a water-based quick-drying coating for casting and a preparation method thereof, belonging to the technical field of casting coatings. Background In the casting process, the quality of the working interface between the casting mould (core) and the high-temperature molten metal is seriously affected, and the casting quality is generally improved by coating a layer of casting coating on the surface of the casting mould (core), so that the method is economical, practical and effective. The casting coating can reduce the surface roughness of the casting, obtain the casting with smooth surface, effectively avoid the sand sticking of the casting surface, improve the surface strength of casting mould (core), reduce and avoid the defects of sand holes, sand inclusion and the like of the casting, adjust the cooling speed of the casting, shield harmful elements, prevent the defects of the casting such as air holes, sulfur increase, carburetion and the like, reduce the cleaning workload of the casting, improve the labor environment, reduce the production cost, and according to rough statistics, the casting coating can reduce the production cost of the casting by more than 5 percent, and has remarkable economic benefit. In recent years, with the increasing demand for casting quality, casting coating materials have become one of the indispensable molding materials in casting production. Casting paints can be classified into alcohol-based paints and water-based paints according to the carrier liquid. Alcohol is inflammable matter, and the carrier liquid is removed after ignition, so that the alcohol-based paint has the advantages of complete application and drying in several minutes, shortened production period and other disadvantages. The alcohol-based paint mainly adopts methanol, ethanol and isopropanol as carrier liquid, the methanol is toxic, has strong pungent smell, is harmful to physical and mental health of practitioners after long-term contact and inhalation, is flammable and explosive, has potential safety hazards in the production, transportation, storage and use processes of the paint, has poor suspension property and construction property, serious brush marks and difficult leveling, has relatively high alcohol price, increases production cost, volatilizes into air to pollute the environment, generates a large amount of CO 2 after combustion, and is against the requirements of energy conservation and environmental protection. The water-based paint has the advantages of no toxicity, no smell, low price, stable performance, safety and environmental protection, and meets the development concept of the green paint, so the water-based paint has obvious advantages in the aspects of production cost, paint performance, safety and environmental protection, and the like, compared with the alcohol-based paint, and is the first choice for developing and popularizing the green environment-friendly paint. With the strictness of safety and environmental protection regulations, the application of alcohol-based paint is limited and gradually replaced by high-performance and environmental-friendly water-based quick-drying paint because of the deep-drawn human heart of the green and sustainable development concept. The water-based quick-drying paint for casting can realize quick drying at room temperature (25+/-1 ℃), is energy-saving and emission-reducing, is safe and environment-friendly, and has important economic and social benefits. The water-based casting coating is prepared from polyvinyl acetal resin powder, drying oil, water glass, talcum powder and other materials, is environment-friendly, has good suspension property and workability, but has slower drying speed, about 5 hours of full drying and larger gas generation amount. At present, the water-based paint is commonly used as inorganic binders such as water glass, silica sol, clay and the like, and the organic binders such as polyvinyl alcohol, polyacetic acid emulsion, water-soluble phenolic resin and the like, so that the water-based paint prepared from the binders has longer drying time and slow drying speed. Polyvinyl alcohol water-based self-drying paint (CN 85100565A) was developed at the university of Dongnan, and the paint was self-dried for 24 hours. Feng Shengshan et al, invented a water-based self-drying/quick-drying sand casting coating and a preparation method thereof (CN 103878302B). The invention is prepared from materials such as room temperature self-crosslinking biphenyl acrylic emulsion, quick-drying silica sol, water reducing agent, sintering stripping auxiliary agent and the like, the drying time of the paint is 90-105 min. The main reason for limiting the popularization and application of the water-based casting coating is that the drying time is long, and special equipment is needed for drying in most cases, so that the producti