JPH06292939A - Stock solution of releasant for molding green sand mold - Google Patents

Abstract

PURPOSE:To form the uniform releasing film which is not repelled even when the oil remains on the surface of a mold by consisting of strong basic amine and higher fatty acid and/or ethylene glycol as essential components, diluting the stock solution with water to an appropriate viscosity and using it in the form of aqueous solution. CONSTITUTION:The stock solution of the releasant constitutes of strong basic amine such as morpholine and higher fatty acid such as oleic acid and/or ethylene glycol or the like as essential components and is regulated through mixing and adding. When the stock solution is coated on the surface of a model for molding the green sand mold, it is diluted to an appropriate viscosity to be used as the releasant. Because the stuck solution of the releasant can be diluted with water, it is not bulky in storing or carrying, and the storage and carriage is facilitated. In the composition of the releasant when it is coated, no oil of hydrocarbon based is used, and the resouries saving and fire safety are improoved. A uniform releasing film can be formed on the surface of the mold, and the releasant can be coated in the form of the aqueous solution. The leakage resistance for the mold when used as the releasant can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release agent stock solution for green molding used in the form of an aqueous solution.

[0002]

The most primitive mold, the raw mold, is
Compared to other thermosetting, self-curing, and gas-curing molds, molding productivity is good, mold materials are inexpensive, and they can be used repeatedly. Mainstream of molds.

As a mold release agent for green molding, the same applicant as the applicant of the present application used a water-in-oil type in which a surfactant was used as a dispersant and a water phase was dispersed in a hydrocarbon oil phase ( W / O
(Type) emulsion systems have been proposed (see Japanese Patent Publication No. 63-29625).

[0004]

However, the above-mentioned type of release agent has the following problems.

(1) The emulsion form is water-in-oil (W /
Since it is type O), it cannot be diluted with water. For this reason, it was necessary to prepare the composition from the time of manufacture to the time of use, and transportation and storage were troublesome.

(2) Further, from the viewpoint of the stability and releasability of the liquid, the water content is limited to about 60%, which is not always sufficient from the viewpoint of resource saving and fire safety.

In this case, an oil-in-water (O / W) type emulsion may be used as the release agent, but it is difficult to form a uniform release film on the surface of the mold after it has been used for molding. Was said. The reason for this is that the main agent for releasing action is hydrocarbon oil, so oil remains on the surface of the mold (particularly the mold) after the release agent is applied and used for molding, and the water-based O / W
With a mold emulsion release agent, when applied to the mold surface,
This is because they will be repelled.

In view of the above, it is an object of the present invention to provide a release agent stock solution for green molding which can be used in the form of an aqueous solution and does not require the use of hydrocarbon oil.

[0009]

The stock solution of a mold release agent for green molding according to the present invention solves the above problems by the following constitution.

A stock solution of a release agent for green molding, which comprises a strongly basic amine, a higher fatty acid and / or ethylene glycol as essential components, and which is diluted with water to an appropriate viscosity to be used in the form of an aqueous solution. Characterize.

[0011]

[Detailed description of means]

(1) The mold release agent stock solution for green molding of the present invention contains a strongly basic amine, a higher fatty acid and / or ethylene glycol as essential components.

Examples of the strongly basic amine include morpholine, piperidine, piperazine, pyrrolidine, pyrrole, imidazole, diethylamine and benzylamine.

The higher fatty acid has 8 to 2 carbon atoms.
0 oleic acid, linoleic acid, lauric acid, palmitic acid, stearic acid, etc. can be mentioned, and derivatives thereof can include ester / amide derivatives thereof.

The above basic amine 100 of this higher fatty acid
The amount of higher fatty acid to be mixed is 10 to 50 parts, and preferably 20 to 40 parts. The higher fatty acid acts as a barrier agent that avoids contact between the sand and the mold.

Examples of the ethylene glycols include ethylene glycol, diethylene glycol, triethylene glycol and the like.

The blending amount of the ethylene glycol with respect to 100 parts of the basic amine is 20 to 80 parts, and preferably 30 to 60 parts. Ethylene glycols act as a lubricant when made into an aqueous solution. (2) Although not necessarily required, a surfactant is added to the stock solution of the releasing agent in an amount of 30% or less, preferably 15% or less of the blending amount of the higher fatty acid to assist dispersibility of the higher fatty acid. It is desirable to do. Non-ion, anion, cation,
Any zwitterionic type may be used, but the following anionic type is particularly preferable from the viewpoint of improving the wettability of the aqueous solution.

Anionic surfactant: higher fatty acid alkali salt (soap), sodium alkyl sulfate, 2-alkyl sodium sulfate, sodium alkylbenzenesulfonate, sodium α-olefinsulfonate, sodium N-acylamino acid, sodium alkylnaphthaleneate , Sodium N- (2-sulfo) ethyl-N-methylalkanamide, 2-sulfosuccinic acid dialkylamide.

(3) In addition to the above-mentioned essential components, when the stock solution is made into an aqueous solution, it is usually desirable to add water as a solubilization promoter in an amount of not more than half the amount of the essential components. This is to increase the safety (fire) of the concentrate.

B. The mold release agent stock solution of the present invention is prepared by mixing and adding the above-mentioned respective compounding agents at the same time, stirring the mixture with a mixer or the like, and storing and transporting in that state. When it is applied to the model surface for green molding, it is diluted with water to an appropriate viscosity (usually 1 to 30 cP) and used as a release agent.

Since it can be diluted with water, the release agent stock solution of the present invention is not bulky at the time of storage and transportation, and can be easily stored and transported.

Further, since the hydrocarbon-based oil is not used at all in the composition of the release agent at the time of coating, it contributes to resource saving and improvement of fire safety.

(4) The mold release agent prepared by diluting the stock mold release agent solution with water by the above method is applied to a model or the like when molding a green mold. Applicable models are not limited to metal models (cast iron, copper alloy, aluminum alloy, steel, etc.), but may be plastic models (epoxy resin, etc.), plaster models, wooden models, and the like. The application method is usually spray application, but any method such as brush application or dip application may be used.

Further, the coating amount of the release agent is usually 2
0 to 400 ml / m ² .

Next, using the model, molding is continuously performed by various molding methods such as squeeze, jolt, blowing, and sand slinger.

[0025]

The stock solution of the mold release agent of the present invention is a stock solution of the mold release agent of the green mold, which comprises a strongly basic amine, a higher fatty acid and / or ethylene glycol as essential components, With the constitution characterized by being diluted with water to a suitable viscosity and used in the form of an aqueous solution, the following actions and effects are exhibited.

As shown in the examples described below, even when oil remains on the surface of the mold (particularly the mold) after the mold release agent has been applied and used for molding, when the oil is left on the mold surface, Not repelled,
A uniform release film can be formed on the mold surface, and the release agent can be applied in the form of an aqueous solution. It is presumed that this is because the wettability with respect to the mold when used as a release agent is improved.

Therefore, since the release agent stock solution of the present invention can be diluted with water, it does not become bulky during storage and transportation, and storage and transportation becomes easy.

Further, since hydrocarbon oil is not used at all in the composition of the release agent at the time of coating, it contributes to resource saving and improvement of fire safety.

[0029]

EXAMPLES Examples carried out to confirm the present invention will be described below together with comparative examples.

A. Test Method In Examples A to H and Comparative Example 2, the mixture of the formulation shown in Table 1 was manually stirred with a glass rod in a beaker to prepare each release agent stock solution.

Then, water for dilution was added to each release agent stock solution so as to have the composition shown in Table 1 while manually stirring with a glass rod in the same manner as above to prepare release agents.

Each mold release agent is spray-applied from a distance of 40 cm to the inner surface of a metal model 1 having a cross section shown in FIG. 1 and made of chrome-plated cast iron (coating device: Meijisha, caliber: 0.
13 mm, air pressure: 392 kPa, coating time: 1 second) (per molding).

Immediately after that, green sand material 3 with a water content of 3.5%
Was put into the inner surface of the metal model 1, and the squeeze head 5 was used to perform squeeze molding. The molding conditions were as follows: raw sand input: 80 g, squeeze pressure: 980 kPa, molding height: about 13 mm. Then, the following items were tested.

(1) Releasability (degree of clinging): After molding, the metal model was inverted and dropped vertically from a height of 10 cm to release the molding mold from the metal model 1. The degree of clinging of the raw sand to the metal model 1 at that time was visually determined. Then, the molding was repeated, and the continuous mold releasability (mold releasability after 6 times molding) was judged together with the initial mold releasability.

The evaluation criteria are as follows.

⊚: Very good, ◯: Good, Δ: Some sand particles remain, Χ: Sand particles cling.

(2) Liquid stability: After the release agent for coating was prepared, it was allowed to stand in a room for 24 hours, and the state of the liquid was visually judged.

The evaluation criteria are as follows.

⊚: The liquid is not separated for 24 hours and the dispersion is beautiful.

◯: No separation occurs after 24 hours

Δ: Separation occurs within 24 hours.

B. Test results and evaluation Table 2 shows the test results.

(1) In terms of releasability, each Example of the present invention is superior to Comparative Examples 1 and 2, and it is found that the initial releasability as well as the sustained releasability are good. It

(2) Regarding the liquid stability, it can be seen that the examples of the present invention exhibit the same stability as that of Comparative Examples 1 and 2.

[0045]

[Table 1]

[0046]

[Table 2]

[Brief description of drawings]

FIG. 1 is a schematic view of a squeeze molding method when a releasability test or the like is performed.

[Explanation of symbols] 1 ... metal model, 3 ... green sand, 5 ... squeeze head,

Claims (2)

[Claims] 1. A stock solution of a mold release agent for green molding, which comprises a strongly basic amine, a higher fatty acid and / or ethylene glycol as essential components, and is diluted with water to an appropriate viscosity to be used in the form of an aqueous solution. A stock mold release agent stock solution for green molding. 2. An aqueous solution type mold release agent for green molding, comprising:
A mold release agent for green molding, which comprises a strongly basic amine and higher fatty acid and / or ethylene glycol as essential components.