Inorganic casting bonding agent based on phosphate

Abstract

The invention relates to an inorganic bonding agent for casting, which is an inorganic casting bonding agent based on phosphate applied to hot core technology. The phosphate casting inorganic bonding agent consists of phosphate solution, polyvinyl alcohol [CH2CH(OH)]n solution and a metal oxide curing agent; when being applied to preparing sand type or sand core, by taking the new sand according to parts by weight as reference, the phosphate casting inorganic bonding agent comprises the following components: 100 parts of new sand, 0.1-1 part of metal oxide curing agent, 0.5-2 parts of polyvinyl alcohol solution, and 3-5 parts of phosphate solution. In the invention, based on the phosphate casting inorganic bonding agent, hydrophobic nodes are added in condensed phosphate space lattices sothat the rate of contacting with water is reduced and the wet resistance is obviously improved; for the sand type or sand core prepared by taking phosphate as the main body of the casting bonding agent, no harmful product can be produced during the process of casting production compared with organic resign bonding agent; the added polyvinyl alcohol for improving the wet resistance does not like benzene-containing organic resin to cause the production of harmful gas because of incomplete combustion.

Description

technical field [0001] The invention relates to an inorganic binder for casting, that is, a phosphate-based inorganic casting binder used in a hot core process. Background technique [0002] As the foundation of the manufacturing industry, the foundry industry has entered an unprecedented period of rapid development with the rapid growth of China's manufacturing industry, especially the automobile industry. [0003] At present, a large amount of resin binder is required in the production process of high-grade castings, and a large amount of free formaldehyde and free phenol will be produced in the production process of thermally cured coated sand; the cold box method requires toxic triethylamine gas The role of catalysis to realize the methylol (-CH 2 OH) and the (-N=C=O) group in polyisocyanate to generate solid urethane phenolic formaldehyde; whether it is hot or cold, complete or incomplete combustion of the resin after casting pouring will produce a large amount of Har...

AI Technical Summary

Problems solved by technology

[0005] Although as early as 1978, U.S. Patent US4127157 proposed a phosphate-based casting binder; however, the biggest disadvantage of the phosphate binder is that it has obvious hygroscopicity, and the moisture absorption problem leads to the phosphate space formed by solidification. The grid nodes are disconnected and lose strength, which cannot guarantee the shape of the sand mold or sand core, which affects the storage time of the sand core; bring harm

In order to solve the problem of hygroscopicity, Zhang Youshou of Hubei University of Technology and others used the method of adding various oxides to enhance the bonding strength of phosphate to improve the moisture resistance, but the effect was not ideal, and it brought difficulties to the regeneration of old sand; Patent CN10941045A proposes a curing agent preparation method for phosphate binders, which reduces the possibility of powdery curing agent generating dust, but adds benzene-containing organic resin