Curing agent of self-hardening furan resin sand and preparation method thereof

Abstract

The invention relates to a curing agent of self-hardening furan resin sand, which comprises the following components in portions by weight: 1-300 portions of toluenesulfonic acid, 10-300 portions of xylene monosulfonic acid, 1-170 portions of sulfuric acid, 200-800 portions of phosphoric acid, 1-200 portions of methyl sulfate, 1-50 portions of ethanol, 1-50 portions of methanol, 40-900 portions of water and 0.05-1.0 portion of assistant. The preparation method comprises the following steps: (1) prefabricating the toluenesulfonic acid, the xylene monosulfonic acid and the methyl sulfate; (2) preparing all the raw materials according to the proportion of the curing agent; and (3) synthesizing the curing agent by the following steps: (a) mixing the toluenesulfonic acid, the xylene monosulfonic acid, the methyl sulfate and the sulfuric acid to react for 1.0 hour; (b) cooling to 55 DEG C, adding the mixture of methanol and ethanol to react at 50-70 DEG C for 1.0 hour; (c) adding the phosphoric acid to react at 55-70 DEG C for 1.0 hour; and (d) cooling to 50 DEG C, and adding water and assistant; and discharging after evenly mixing. The curing agent can adapt to the long (super long) use time in the molding process of large castings at high air temperature (above 28 DEG C) and high sand temperature (30-50 DEG C), and solves the problem that the large (super long and large) castings are difficult to produce since the temperature of the reclaimed sand can not drop to the designed value due to various reasons in the foundry corporations.

Description

technical field [0001] The invention relates to a curing agent, in particular to a curing agent used in a self-hardening furan resin sand molding (core) process, which belongs to the field of chemical raw materials. Background technique [0002] The curing agent used in the molding (core) process of self-hardening furan resin sand is generally HG / T2345-92 sulfonic acid curing agent or its derivative curing agent. 30 ℃, it is difficult to meet the needs of long usable time for large-scale casting molding production (casting weight 20-150 tons, generally 8 to 30 minutes), especially in summer when the temperature exceeds 28 ℃ or the sand temperature exceeds 30 ℃, The above curing agent is even more incompetent. It can neither meet the usable time required for molding production, nor can it ensure that the molding sand has the required tensile and compressive strength values ​​for production, and at this time, there is a strong odor such as formaldehyde in the working area. S...

AI Technical Summary

Problems solved by technology

[0003] The object of the present invention is to provide a kind of no-hardening furan resin molding sand that can adapt to higher sand temperature (30-50°C) and has a longer A curing agent that can be used for a long time; further, a series of models of the curing agent are provided, so that the no-hardening furan resin sand can have a longer usable time in a wide range of sand temperatures (-10 to 50°C); Furthermore, the mixed use of the curing agent is provided, which can avoid and solve various problems caused by the mismatch between the curing agent model and the sand temperature

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