A casting coating using calcium-based bentonite as a suspending agent and its preparation method

Abstract

The invention discloses a casting coating adopting calcium bentonite as a suspending agent and a preparation method, and belongs to the coating field. The casting coating comprises refractory aggregate, the calcium bentonite, rosin, polyvinyl butyral, sodium salt (a mixture of sodium chloride and sodium carbonate), carboxyl methyl cellulose (CMC), boric acid, water, a surface active agent (JFC) and alcohol. The coating has the quite good suspension property; the cost of the suspending agent is lower than that of a traditional sodium bentonite suspending agent by 50% and is only 10% of the costof a lithium bentonite suspending agent and 5% of the cost of organobentonite; raw material resources are wide; the properties, such as the low gas-forming property, the good anti-foaming property, crack resistance and permeability, of the coating are quite good; the cost performance is high; and a product has wide application prospects.

Description

technical field [0001] The invention belongs to the field of coatings, and in particular relates to a casting coating using calcium-based bentonite as a suspending agent and a preparation method thereof. Background technique [0002] The suspending agent traditionally used in sand mold alcohol-based casting coatings is organic bentonite or lithium-based bentonite, and sodium-based bentonite is also used, while calcium-based bentonite exists mainly in nature. Except for calcium-based bentonite, the other types need to be further processed or modified to obtain, and the cost is very high. [0003] "A dry paste casting coating and its preparation method and application method", (Chinese patent: 201710110724.5) proposes a coating with calcium-based bentonite as a suspending agent, but this patent still has technical defects, such as the need to change the viscosity of the coating It is very inconvenient to use if the adjustment is high, it is easy to foam when it is ignited, an...

AI Technical Summary

Problems solved by technology

[0003] "A dry paste casting coating and its preparation method and application method", (Chinese patent: 201710110724.5) proposes a coating with calcium-based bentonite as a suspending agent, but this patent still has technical defects, such as the need to change the viscosity of the coating It is very inconvenient to use if the adjustment is high, it is easy to foam when it is ignited, and the coating is easy to crack (and there is silica sol in the coating, which is more prone to cracking), and the coating The permeability of the coating is not good, the combination of the coating and the mold is not strong, and the casting is prone to sand sticking. In order to improve the suspension rate, the coating uses a higher content of polyvinyl butyral. In order to improve the strength, the rosin binder The content is also very high, all of which make the paint very gassy

Through the search, it is found that there is no report on the preparation of casting coatings with good performance by using calcium-based bentonite as the suspending agent.