JP2000102842A - Mold molding composition and mold molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die molding method capable of improving working environment in mold molding and obtaining a high strength, high quality mold in a room temperature gas hardening mold molding method. SOLUTION: In this mold molding method, a granular refractory aggregate which is coated with a binder containing a polyol compound and polyisocyanate compound, is introduced in a molding flask for molding, and then a gasified hardening accelerator is introduced into the molding flask. In this case, the hardening accelerator to be used by gasifying is a mixed solution containing a tertiary amine and alcohols and/or water.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a room temperature gas-curing mold molding method, which improves the working environment during mold molding and provides a high-strength, high-quality mold. About.

2. Description of the Related Art Conventionally, as a method of manufacturing a casting mold, a polyol compound and a polyisocyanate compound are mixed with a granular refractory aggregate, and the mixture is introduced into a mold and molded.
There is a so-called amine cold box method in which a tertiary amine gas is aerated and cured to obtain a mold. This method is advantageous in terms of energy consumption because heating is not required for production, and has the advantage that the molding cycle is short and the productivity is high. However, in the prior art, a large amount of amine gas must be used as a catalyst,
This is deteriorating the working environment. In addition, when the amount of amine is reduced, the strength of the mold is greatly reduced, sufficient handling strength is not obtained, and the quality of the mold is deteriorated.
Therefore, there is a drawback that casting defects occur.

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned drawbacks, the use of a mixed gas of tertiary amine, alcohols and / or water has greatly reduced the amount of amine used. The inventors succeeded in obtaining a mold having reduced mold strength and high mold strength, and completed the present invention. In the prior art, it has been suggested that during curing, the incorporation of water vapor should be avoided to cause deterioration in strength. However, by using the technique of the present invention, it is possible to greatly improve the strength of the mold. That is, by simultaneously passing the mixed gas of alcohols and / or water when the amine gas is passed, the curing reaction between the phenol resin and the isocyanate resin is promoted, and the mold strength is improved. Hereinafter, the present invention will be described in detail. The present invention provides a polyol compound,
In a method for producing a mold, a granular refractory aggregate coated with a binder containing a polyisocyanate compound is introduced into a mold and molded, and then a curing accelerator is gasified and introduced into the mold and cured. Wherein the effect accelerator used is a mixed solution containing a tertiary amine and an alcohol and / or water, and the curing accelerator gas is a tertiary amine and an alcohol; And / or a mixed gas containing water. The alcohols used in the present invention include methanol, ethanol, propanol, butanol and the like. As the tertiary amine, triethylamine, dimethylethylamine and the like can be used. The mixing ratio of the tertiary amine, the alcohol and the water is arbitrary, but from the viewpoint of reducing the amine and increasing the strength of the template, the total concentration of the alcohol and / or water in the mixed gas is from 20 to
More preferably, it is 95% by weight.

EXAMPLES Hereinafter, the mold making method according to the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist. [Example 1] 800 parts by weight of phenol, 445 parts by weight of 86% formaldehyde and 200 parts by weight of toluene were charged into a separable flask equipped with a reflux dehydrator, and then 8 parts by weight of zinc acetate was added. The reflux dehydration reaction was continued for 4 hours. Thereafter, the condensed water and the solvent were removed under vacuum, and the mixture was cooled. IR and NM products
Analysis by R confirmed that the resin was a benzylic ether type phenol resin. A 1: 1 mixed solvent of ethylene glycol diacetate and an aromatic solvent (manufactured by Maruzen Petrochemical Co., Ltd. under the trade name Swazole) as the reaction product 15
79 parts by weight of the polyol compound solution 27 were mixed.
70 parts by weight were obtained. Next, 554 parts by weight of swazole was added to 2216 parts by weight of diphenylmethane diisocyanate and mixed to obtain 2770 parts by weight of a polyisocyanate compound solution. Next, 200 parts by weight of triethylamine, 100 parts by weight of isopropanol, and 200 parts by weight of water were mixed to obtain 500 parts by weight of a curing acceleration solution. Next, Iide F6 quartz sand 1
10 parts by weight of the above polyol compound solution and 10 parts by weight of the polyisocyanate compound solution were kneaded with respect to 000 parts by weight to obtain kneaded sand. The kneading sand was blown into a mold for taking five test pieces of 20 × 20 × 150 mm at a blow pressure of 2 kgf / cm ² , and then the hardening accelerating solution was vaporized to 1.5 parts by weight with respect to the kneading sand. And a cured mold was obtained. At this time, the transverse rupture force was measured immediately after curing and 24 hours later. In addition, 10 panelists were placed in a range of 5 m around the molding machine, and a sensory test of odor during molding was performed. Table 1 shows the results. [Example 2] 200 parts by weight of triethylamine, 50 parts by weight of methanol and 250 parts by weight of water were mixed to obtain 500 parts by weight of a curing acceleration solution. Next, the kneaded sand obtained in Example 1 was blown into a mold in the same manner as in Example 1, and the hardening promoting solution was vaporized to 1.5 parts by weight with respect to the kneaded sand, introduced into the mold, and cured. A mold was obtained. The same test as in Example 1 was performed. [Example 3] The kneaded sand obtained in Example 1 was blown into a mold in the same manner as in Example 1, and the hardening accelerating solution obtained in Example 1 was vaporized to 1.0 part by weight with respect to the kneaded sand. It was introduced into a mold to obtain a cured mold. The same test as in Example 1 was performed. [Comparative Example 1] The kneaded sand obtained in Example 1 was blown into a mold in the same manner as in Example 1, and 1.5 parts by weight of triethylamine was vaporized with respect to the kneaded sand, and introduced into the mold. I got The same test as in Example 1 was performed.

[Table 1]

As described above, by using the composition for mold making and the method for mold making of the present invention, the working environment at the time of mold making can be improved, and a high-strength, high-quality mold can be obtained. .

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiaki Itozawa 700 Shukudaidaicho, Takasaki City, Gunma Prefecture Inside Gunei Chemical Industry Co., Ltd. Co., Ltd. F-term (reference) 4E092 AA23 AA31 AA32 AA55 BA04 BA12 CA03

Claims (5)

[Claims] 1. A particulate refractory aggregate coated with a binder containing a polyol compound and a polyisocyanate compound is introduced into a mold and molded, and then a curing accelerator is gasified and introduced into the mold. A method for producing a mold, wherein the effect accelerator used is a mixed solution containing a tertiary amine, alcohols and / or water. 2. The composition according to claim 1, wherein the curing accelerator has a total concentration of alcohols and / or water in the solution of 20 to 95% by weight. 3. A granular refractory aggregate coated with a binder containing a polyol compound and a polyisocyanate compound is introduced into a mold, molded, and then cured by introducing a curing accelerating gas into the mold. A method for producing a mold, wherein the curing-acceleration gas is a mixed gas containing a tertiary amine, an alcohol, and / or water. 4. The method according to claim 3, wherein the total concentration of alcohols and / or water in the mixed gas is 20 to 95% by weight. 5. A granular refractory aggregate coated with a binder containing a polyol compound and a polyisocyanate compound is introduced into a mold, molded, and then cured by introducing a curing accelerating gas into the mold. A method for producing a mold, wherein the curing accelerating gas is obtained by gasifying a mixed solution containing a tertiary amine and an alcohol and / or water.