Formula and preparation process of alcohol group nanometer composite and surface modified dry powder mold paint

Abstract

The invention relates to an auxiliary material for casting and moulding, in particular to a formula of alcohol group dry powder mold paint for sand mold casting. The dry powder mold paint comprises surface modifier, suspending agent, binder and refractory powder, wherein the surface modifier is 0.6-4.2wt% of refractory powder, the suspending agent is 4.0-8.0wt% of refractory powder and the binderis 4.0-6.2wt% of refractory powder. The alcohol group nanometer composite and surface modified dry powder mold paint of the invention adopts nanometer layered clay and nano-SiO2 to form composite suspending agent so that the controllability of operation technological parameters of the alcohol group dry powder mold paint is good and the process performance and operating performance of the obtainedpulp-type paint can both meet the demand of the casting factory.

Description

Technical field: [0001] The invention relates to an auxiliary material for casting molding, in particular to an alcohol-based dry powder casting coating formula for sand casting and a preparation process thereof. Background technique: [0002] Mold coating is the most effective measure to solve the sand sticking on the surface of castings and improve the surface quality of castings. Among them, the alcohol-based coating is widely used in casting production plants due to its characteristics of ignition drying, good strength and high efficiency. At present, the vast majority of commercialized casting coatings are supplied in the form of paste, and the carrier liquid of alcohol-based coatings is mainly composed of ethanol, methanol, isopropanol, etc., which are flammable and dangerous goods, which inevitably makes Coatings are subject to many constraints in terms of packaging, transportation, storage, etc., especially the long transportation period and high cost; in addition, ...

AI Technical Summary

Problems solved by technology

[0003] Chinese patent CN86105456A discloses a lithium-based bentonite zircon powder powder casting coating. The raw materials such as lithium-based bentonite, zircon powder, resin and titanium dioxide are mixed and milled to make a powder coating, which is directly diluted with ethanol when used. Slurry coating, but because the suspending agent lithium-based bentonite has not caused swelling, the suspension of the mixed slurry coating is poor, resulting in very poor field usability

Chinese patent CN1022173C discloses a method for preparing alcohol-based dry powder coatings. The suspending agent lithium soil is subjected to denaturation treatment, and then mixed with refractory powder, binder and other additives to form alcohol-based dry powder coatings. The preparation process requires very high requirements. If the control is slightly improper, it will affect the performance of the coating, and this process is only suitable for the preparation of low-density refractory powder coatings such as quartz powder and graphite powder. For the zircon powder and chromite powder commonly used in casting coatings , Corundum powder and other high-density refractory powder dry powder coatings, still cannot guarantee its good suspension stability and other process properties

Chinese patent CN100377811C discloses a production method of alcohol-based attapulgite casting coating powder, using sodium-modified attapulgite clay as a suspending agent, and the prepared coating powder can reach a higher suspension rate in ethanol, but the coating The percentage of modified attapulgite clay in the powder is 55% to 85%, and the refractory powder (high alumina + graphite) is only 10% to 45%. The amount of suspending agent is much higher than that of refractory powder, although it makes The obtained slurry paint has good suspension stability, but at the cost of reducing the refractoriness of the paint, so the scope of use of the paint is limited, and it cannot be used in the production of steel castings and large iron castings

However, since the refractory powder is an inorganic material, the suspending agent organoclay and the film-forming compound are both organic materials, the dry powder coating made by mixing is easy to form segregation (especially after long-distance transportation and long-term storage), resulting in dry powder coating composition Inhomogeneity, which makes the performance of the mixed slurry coating fluctuate, and it is difficult to control when using