Cold core box binder and casting molding body

Abstract

The invention discloses a cold core box binder and a casting molding body and belongs to the technical field of binders. The cold core box binder comprises a first component. The first component is composed of, by weight, 40-80 parts of benzyl ether phenolic resin, 1-50 parts of high-boiling-point ester and / or hydrocarbon solvents and 0.1-10 parts of tackifying auxiliaries, wherein the content of hydroxymethyl of the benzyl ether phenolic resin is 32%-50%. According to the cold core box binder, the resin using amount is decreased to 0.55%-0.75% under the condition that the strength of a resin sand mold core is ensured; compared with the prior art, the resin using amount is greatly decreased, and the collapsibility of the resin sand mold core is greatly improved; and meanwhile, the residual quantity of tar on a metal mold is decreased, and the production efficiency is improved.

Description

technical field [0001] The invention relates to the field of binder technology, in particular to a cold box binder for colored casting resin sand and a casting molded body. The binder is mixed with casting aggregate to form a casting mixture, and the It is used to form a core mold for the manufacture of cast metal castings, especially suitable for casting non-ferrous alloys. Background technique [0002] In the foundry industry, the existing cold box binder is a two-component resin, which is cured under the catalytic action of triethylamine, dimethylethylamine, dimethylisopropylamine, etc. In order to ensure that the resin sand core has sufficient strength and is convenient for mold taking, handling and storage, the amount of resin added is generally high, between 1.0-2.0%. When the binder is used in the production of cast iron or cast steel, due to the high pouring temperature (generally above 1400°C), the binder can be completely decomposed by heat, and the sand core is e...

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Problems solved by technology

[0003] When the existing cold box binder is applied to non-ferrous casting, under the condition that the strength of the resin sand core is guaranteed to meet the service performance, the amount of resin added is reduced to 0.85-1.2%, but due to the low pouring temperature (like aluminum alloy pouring temperature 700-800℃), the binder in the sand core is not completely decomposed by heat, and the resin sand cannot be completely collapsed, making it very difficult to shake out the sand; the current resin also causes a high amount of residual tar on the metal mold after pouring, which not only affects casting quality, and the residual tar on the mold needs to be continuously cleaned during production, which reduces production efficiency

[0004] At present, many researchers are trying to solve this problem. As US Patent No. 4,946,876 discloses the measures of adding polyester polyol to improve collapsibility, but there is a shortcoming of low sand core strength, and the problem of not completely improving collapsibility exists; U.S. Patent US5132339 discloses the measures of adding polyethylene glycol (molecular weight 400) to improve the collapsibility, but still has the disadvantage of poor moisture resistance, and the collapsibility has not been greatly improved; Chinese patent CN101524737A discloses the use of dibasic alcohols to react the original resin system Sexual modification, improve the thermal decomposition performance of resin, solve the problem of sand core collapse at lower pouring temperature, but there is a high amount of residual tar on the metal mold after pouring, which affects the quality of castings, and the residue on the mold still needs to be cleaned continuously during production tar, which brings the disadvantage of low production efficiency

[0005] The applicant’s previous Chinese patent CN101147953 disclosed a high-performance low-smoke flame-retardant amine-based cold box binder, which is a two-component binder that can increase the strength of the resin, but does not completely improve the collapse of the resin sand core question

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