JP3115398B2 - Mold release agent composition for curable mold for vibration molding and mold molded using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release agent for a hardening mold for vibration molding and a mold molded using the same. More specifically, when a molding sand mold used in the production of a casting is manufactured from a mold, strong vibration is applied to the mold to enhance the filling property of the molding sand, and the molded sand mold is subjected to vibration molding. The present invention relates to a release agent used for facilitating removal from a mold, and a mold molded by vibration using the release agent.

[0002]

2. Description of the Related Art In a casting method for producing a casting having a desired shape and size by melting metal, a sand mold is used as a mold. The sand mold is composed mainly of mineral sand such as silica sand and mixed with an inorganic binder such as water glass and an organic binder such as furan resin. , Molds, resin molds, etc. However, since the sand mold contains a binder, mineral sand adheres to the surface of the mold during sand mold manufacture (this is called squeak), which not only prevents accurate sand mold manufacture, In some cases, the productivity of the mold may be impaired, such as not being able to remove the sand mold from the mold.

[0003] In order to solve such a problem, various release agents are applied to the mold in order to facilitate the mold release from the mold. As such a release agent, paraffin wax, silicon oil, or a lubricating component such as mineral oil, or silica, alumina, talc, paint and the like in which inorganic powder such as graphite is dispersed and slurry has been used, In addition, release paints such as varnish, epoxy resin, urethane resin, phenol resin, and silicone resin are used.

[0004]

On the other hand, with the development of molding methods in recent years, strong vibrations are given to
Since the molding sand can be filled up to the corners of a mold having a complicated shape and the filling density is increased, a vibration molding process capable of obtaining a cast product having a good casting surface has been proposed (for example, JP-A-3-161145). Reference). In this vibration molding process, the molding sand filled in the formwork vibrates vertically and horizontally in the formwork due to strong vibration, so the service life of conventional mold release agents is short, and strong smearing occurs on the formwork surface. Since the workability deteriorates remarkably as the sand mold breaks during the removal of the mold, an effective release agent has been required.

[0005] The conventional release agent does not take the above-mentioned vibration molding process into consideration, and is effective only in a molding method in which molding sand does not flow and vibrate in a mold. That is, when the conventional mold release agent is applied to the above-mentioned vibration molding process, it is peeled off from the surface of the mold along with the vibration flow of the molding sand and is worn away, so that the original mold release effect cannot be exhibited. Met. The present invention is intended to significantly improve the durability, which is a drawback of the above-described conventional release agent, and aims to remarkably improve the number of times of use until re-application as well as the original release property. I have.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In other words, in the casting method of manufacturing a casting having a desired shape and size by melting metal, when a sand mold serving as a mold is manufactured using a mold, a vibration molding process that applies strong vibration to the mold is performed. In order to remove the sand mold from the mold by providing a mold release agent that is durable against the vibrational flow of the molding sand in the mold, As a result of intensive studies to develop a mold release agent that makes it easy and maintain its release property for a long time, fine particles of organic polymer compound having a specific particle size are used as a lubricant component, and The present inventors have found that the releasability and the durability are greatly improved by using a polymer compound to be used in combination, and the present invention has been completed.

That is, the present invention provides the following (a), (b) and
(c) The component is an essential component, and the weight ratio (a) / (b) of the component (a) to the component (b) is 0.1 or more and 5 or less. The present invention relates to an agent composition and a mold molded using the same. (a) Fine powder of an organic polymer compound having an average particle diameter of 1 to 100 μm (b) Organic polymer compound that does not dissolve the above (a) component (c) Does not dissolve the (a) component, but (b) Single or mixed organic solvent capable of dissolving the components The fine powder of the organic polymer compound (a) used in the present invention includes nylon resins such as nylon 6, nylon 66 and nylon 12, and tetrafluoride. Resin, 4,6-fluorinated resin, PFA resin, fluorocarbon resin such as tetrafluoroethylene-ethylene copolymer, vinylidene fluoride resin, polyethylene resin, silicone resin, polyolefin resin, etc., preferably nylon resin 4 is a fluoropolymer. The average particle size of the fine powder of these organic polymer compounds is 1
100100 μm, preferably 3-50 μm.
μm. If the average particle size is less than 1 μm, the lubricating effect is poor and the releasability is inferior.
The releasability becomes poor. The amount of the fine powder of the organic polymer compound is 1 to 1 with respect to the total amount of the release agent.
It is preferably 30% by weight, more preferably 2 to 15% by weight. If the addition amount is less than 1% by weight, the lubricant effect per unit area of the application is low due to the low density of the lubricant, whereas the addition amount is 30% by weight.
If it exceeds, the strength of the release agent film is lowered, and the durability becomes poor. Since the lubricant effect of the component (a) largely depends on the "rolling" of the particles, a perfect spherical particle shape is optimal.

The organic polymer compound as the component (b) itself serves as a binder for adhering and fixing the fine powder of the component (a) to a mold, and dissolves the component (a). Then, the lubricant effect is lost. In addition, if the component (b) is easily soluble in the binder used in molding the mold, it causes a stain, so that it is necessary to select a component that is insoluble in the binder. For example, in the case of a sand mold using a furan resin as a binder, polystyrene, polyvinyl chloride and the like are preferable. The amount of the component (b) is 1 to 1 with respect to the total amount of the release agent.
It is preferably 20% by weight, more preferably 2 to 15% by weight. If the addition amount is less than 1% by weight, the thickness of the coating film becomes thin, and at the same time, the adhesive strength of the component (a) cannot be ensured, resulting in poor durability. On the other hand, if it exceeds 20% by weight, the viscosity of the release agent itself becomes high, so that the coating film thickness becomes large and uniform coating becomes difficult. Also
The weight ratio (a) / (b) of component (a) to component (b) must be 0.1 or more and 5 or less, preferably 0.5 or more and 4 or less. When the weight ratio of (a) / (b) is less than 0.1, the amount of the lubricant component (a) is too small, and the releasability is poor. (A)
If the weight ratio of / (b) exceeds 5, the component (b) relative to the component (a) becomes too small, and the film strength of the release agent is undesirably reduced.

As the organic solvent for the component (c), any solvent can be used as long as it does not dissolve the component (a) and can dissolve the component (b). For example, aromatic hydrocarbons such as toluene, xylene and benzene, methylene chloride,
Chloride hydrocarbons such as chloroform and carbon tetrachloride, ketone solvents such as methyl ethyl ketone, acetone and cyclohexanone, hydrocarbons such as n-hexane and cyclohexane, ethers such as ethyl ether and butyl carbitol, methyl acetate, acetic acid Acetates such as ethyl and butyl acetate, and alcohols such as methanol and ethanol can be used. However, the solvent is not necessarily required to be a single solvent, and a mixture thereof may be used if necessary. The release agent of the present invention can be applied to a mold by spraying or brushing. In the release agent of the present invention, a dye, a rust preventive, a dispersant, a surfactant and the like can be added as necessary.

[0010]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. Examples 1 to 8 and Comparative Examples 1 to 4 Release agents having the compositions shown in Table 1 were prepared, and their performance was evaluated by the following evaluation experiments. (Evaluation Experiment) A wooden mold having a space of 10 cm in length × 10 cm in width × 30 cm in height was prepared, and the release agent shown in Table 1 was applied to the surface thereof with a brush. After allowing to stand and drying sufficiently, the wooden mold was fixed on a vibration table. Casting sand (furan resin)
4 kg of 1.3% with respect to sand and 40% of curing agent with respect to resin) was applied, and a vertical vibration was applied so that a vibration force of 5 G was obtained. After leaving to stand for 30 minutes to solidify the casting sand, a blanking operation was performed, and the surface state of the sand mold and the surface state of the wooden mold were observed. The same operation was repeated until spots were observed on the entire surface of the wooden mold surface, and the repeated use of the release agent was also tested. Table 1 shows the performance evaluation results of Examples 1 to 8 and Comparative Examples 1 to 5.

[0011]

[Table 1]

* 1: Methyl ethyl ketone From the results shown in Table 1, the release agent composition of the present invention is superior to the comparative product in terms of release performance and repetitive use, and the release properties and surface appearance of the obtained sand mold. It can be seen that is improved.

[0013]

According to the vibration molding process of imparting strong vibration to the mold to enhance the filling property of the molding sand, if the release agent composition of the present invention is used, the molding sand mold used for the production of a casting can be obtained. When manufacturing from a mold, the molded sand mold can be easily removed from the mold, and a sand mold having a good surface condition can be obtained.

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Claims (5)

(57) [Claims] (1) The following components (a), (b) and (c) are essential components, and the weight ratio of component (a) to component (b) (a) / (b)
Is 0.1 or more and 5 or less, a release agent composition for a curable mold for vibration molding. (a) Fine powder of an organic polymer compound having an average particle diameter of 1 to 100 μm (b) Organic polymer compound that does not dissolve the above (a) component (c) Does not dissolve the (a) component, but (b) Single or mixed organic solvents that can dissolve the components 2. The composition according to claim 1, wherein the content of the component (a) is (a), (b) or (c).
The release agent composition for a vibration-molding curable mold according to claim 1, wherein the amount is 1 to 30% by weight based on the total amount of the components. 3. The composition according to claim 1, wherein the content of the component (b) is (a), (b) or (c).
The release agent composition for a curable mold for vibration molding according to claim 1, which is 1 to 20% by weight based on the total amount of the components. 4. The vibration molding curing according to claim 1, wherein the fine powder of the organic polymer compound as the component (a) is a compound selected from the group consisting of a nylon resin, a fluororesin, a polyethylene resin, a silicone resin and a polyolefin resin. Release agent composition for a functional mold. 5. A mold formed by vibration molding using the release agent composition for a curable mold for vibration molding according to claim 1.