Self-hardening sand bonding agent for casting and preparation method and using method thereof

Abstract

The invention relates to a bonding agent for casting, in particular to a self-hardening sand bonding agent for casting and a preparation method and a using method thereof. The self-hardening sand bonding agent for the casting comprises resin and a curing agent, wherein the resin consists of the following components in part by weight: 100 parts of castor oil, 40 to 90 parts of glycerol, 0.1 to 0.2part of calcium oxide, 50 to 90 parts of phthalic anhydride, 5 to 9 parts of dimethylbenzene, 120 to 200 parts of high-boiling point arylhydrocarbon; and the curing agent is prepared by mixing 100 weight parts of isocyanate and 20 to 40 weight parts of high-boiling point arylhydrocarbon. The bonding agent has readily available raw materials and is environment-friendly, equipment required by a synthetic process is simple, and a process condition is easy to control; the bonding agent has high sand mulling flowability, low gas forming amount, high gas forming speed, stable sizes of sand cores / sand molds and smooth surfaces, is convenient to store, and has the excellent effects of resisting sand burning and deformation; and the sand molds are hardened integrally and uniformly, castings have high size accuracy, and sand can be recycled, so the bonding agent is suitable for the production of large-scale steel-casting sand molds.

Description

technical field [0001] The present invention relates to a kind of foundry binder, especially relates to foundry self-setting sand binder and its preparation and use method. Background technique [0002] One of the main methods of the foundry industry for the preparation of metal parts is sand casting, in which disposable patterns are made by mixing, shaping and curing sand with an inorganic or organic binder, which is Used to reinforce molds and cores. The two main methods used to prepare molds and cores are (1) the cold box core method and (2) the no-bake method. Most cold box coremaking methods are based on polyurethane forming binders. See eg US 3,409,579 and 3,676,392. These systems are cured with gaseous quaternary amine catalysts. The polyurethane forming binder system typically consists of a phenolic resin component and a polyisocyanate component which are mixed with sand and cured to form a cured mix prior to compaction. The component phenolic resin in the binde...

AI Technical Summary

Problems solved by technology

Moreover, the binder system has problems such as short usable time, inability to solidify the mold as a whole, and a long time to reach the final strength. It can only be used for small and medium-sized steel casting sand molds, and cannot meet the use requirements of large steel castings. Moreover, during the production process, the existing adhesives will release defects such as toxic gases that are harmful to the environment.