JP2016120521A - Powder release agent and production method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder release agent having high seizure resistance.SOLUTION: A powder release agent is provided with a lubricant 3 having lubricity and being in a liquid state at a normal temperature and a main component particle 1 being formed to be a solid particulate at a normal temperature and having a body part 2 including the lubricant 3. The body part 2 is configured to elute the included lubricant 3 outside when the main component particle 1 is brought into contact with a molten metal poured into the cavity of a casting die. The body part 2 is constituted with an organic compound melted or decomposed at the heating temperature of the casting die. The lubricant 3 is a modified silicone oil.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a powder release agent and a method for producing the same.

  The cast product is manufactured by pouring a high-temperature molten metal poured into a cavity formed in a casting mold, and cooling and solidifying the poured molten metal in the cavity. If the molten metal is in direct contact with the cavity wall surface of the casting mold during casting, the cast product may be seized on the cavity wall surface. In order to prevent this, a mold release agent is applied to the cavity wall surface before the molten metal is poured into the cavity. Since the applied release agent is interposed between the molten metal and the cavity wall surface, direct contact between the molten metal and the cavity wall surface is prevented. That is, seizure of the cast product is prevented. In order to improve the seizure resistance (the ability to prevent seizure of cast products on the cavity wall surface), which is the main function of such a mold release agent, and to reduce the resistance during mold release, various components are added. Including mold release agents.

  Patent Document 1 discloses a powder release agent composed of a powdery substance in which sericite (mineral) or similar mica and an oily substance and / or a resinous substance are firmly bonded. Patent Document 2 is a powder having one or more kinds of self-lubricating properties selected from fatty acids, waxes, oils, resins, etc., and is a powdery or granular solid at normal temperature and liquefied by heat. Disclosed is a powder release agent having Patent Document 3 discloses that an organo-modified silicone obtained by reacting a specific chain silicone with an aromatic hydrocarbon having a specific monoolefin and / or alkenyl group and a specific diacrylate in the presence of a hydrosilation catalyst. Disclosed is a modified silicone-based water-soluble release agent. Patent Document 4 discloses a powder release formed by mixing a powdery or granular release agent base material composed of an inorganic compound used as a lubricant and an organic compound that imparts adhesion to the release agent base material. A mold is disclosed. Patent Document 5 discloses a mold release obtained by mixing a graphite-based solid lubricant on a scale and a non-graphite-based solid lubricant on a scale composed of one or more selected from boron nitride, molybdenum disulfide and talc powder. Agents are disclosed.

Japanese Unexamined Patent Publication No. 7-53980 JP-A-11-209770 JP 2012-130922 A JP-A-3-243242 Japanese Patent Laid-Open No. 9-295102

(Problems to be solved by the invention)
Release agents are roughly classified into liquid release agents and powder release agents. Liquid release agents are further classified into oil-based release agents (water-insoluble release agents) and water-soluble release agents. Among these, at present, water-soluble release agents having high seizure resistance and excellent in flame retardancy are widely used.

  Since the water-soluble release agent contains water as a solvent, when the water-soluble release agent is applied to the cavity wall surface, moisture may remain on the cavity wall surface. In this case, residual moisture on the cavity wall surface is taken into the molten metal poured into the cavity, so that there is a possibility that a cast hole is formed in the cast product or on the cast product surface. In addition, since a large thermal shock acts on the casting mold when the water-soluble mold release agent is applied to the cavity wall surface, when the water-soluble mold release agent is used, deterioration of the casting mold is promoted. Furthermore, when a water-soluble mold release agent is used, equipment cost increases because a waste water treatment facility for preventing water pollution by a used water-soluble mold release agent is necessary. Furthermore, since the mist is generated when the water-soluble release agent is used, the working environment is deteriorated. Thus, many problems occur even when a water-soluble release agent is used.

  On the other hand, when a powder release agent is used, there is no problem caused by using the water-soluble release agent as described above. Further, since the application time of the powder release agent is shorter than the application time of the liquid release agent, the molding cycle can be shortened. However, since the conventional powder release agent is an inorganic solid, when it is applied to the cavity wall surface, a release film is formed only on the portion attached to the cavity wall surface. For this reason, a sufficient release film is not formed at a portion where the amount of powder adhered is small, and therefore conventional powder release agents are inferior in seizure resistance. In addition, the powder release agent contains an inorganic compound (mineral) to improve seizure resistance, and such an inorganic compound remains in the cavity as a solid release agent residue. There is a possibility that an inorganic compound adheres to a cast product formed in the cavity. When solid state release agent residue such as inorganic compounds adheres to the cast product, the adhesive strength decreases when adhesive is applied to the part including the part where the release agent residue is attached in the subsequent process. Or, there is a concern about the deterioration of the paintability of the adhesion site. As described above, the powder release agent is inferior to the water-soluble release agent in seizure resistance and adhesion resistance (ability to prevent the release agent residue from adhering to the cast product).

  An object of this invention is to provide the powder mold release agent which has high seizure resistance, and the manufacturing method of such a powder mold release agent.

(Means for solving the problem)
The present invention is a powder release agent applied to the cavity wall surface of a heated casting mold, and has a lubricity and a liquid in a liquid state at room temperature, and is formed into solid particles at room temperature. A main body particle having a main body part containing a lubricating liquid, and the main body part is in contact with the molten metal poured into the cavity of the casting mold, Provided is a powder release agent that is configured to elute.

  According to the powder release agent according to the present invention, when the main component particles having a solid particle-shaped main body portion containing a lubricating liquid come into contact with the molten metal poured into the cavity, the main body particles are included in the main body portion. Lubricating fluid is eluted to the outside. Accordingly, the lubricating liquid eluted to the outside of the main body spreads on the cavity wall surface, so that the cavity wall surface is covered with the lubricating liquid and a release film is formed. For this reason, the direct contact between the molten metal and the cavity wall surface is prevented, and the occurrence of seizure due to the direct contact between both is prevented.

  That is, the powder release agent according to the present invention forms a release film uniformly on the cavity wall surface by spreading the lubricating liquid on the cavity wall surface like the liquid release agent while being in a powder form. It is configured to be able to. In other words, the powder release agent according to the present invention has a high seizure resistance equivalent to that of the liquid release agent while being a powder release agent. Therefore, according to the present invention, a powder release agent having high seizure resistance can be provided.

  In the present invention, the main body may be configured so that the contained lubricating liquid is eluted to the outside when the main component particles come into contact with the molten metal in the cavity of the casting mold. That is, the lubricating liquid contained in the main body may be eluted from the main body to the outside during a period until the main component particles come into contact with the molten metal in the cavity. More specifically, in the main body, the contained lubricating liquid is externally applied after the powder release agent is applied to the cavity wall surface and immediately after the molten metal contacts the main component particles in the cavity. It is good to be constituted so that it may be eluted. For example, when the powder release agent is applied to the cavity wall surface, the lubricating liquid may be eluted from the main body, or when the main component particles contact the molten metal in the cavity. The liquid may be eluted from the main body to the outside.

  In the present invention, the “cavity wall surface” means a wall surface used for forming a cast product. Accordingly, not only the cavity wall surface of the mold (fixed mold, movable mold) but also the wall surface used for forming a cast product among the accessory parts such as the cast pin and the slide core installed in the cavity are also included in the present invention. Is the “cavity wall surface”. In the present invention, “normal temperature” is a temperature defined by JIS Z 8703, and is 5 ° C. to 35 ° C. (20 ° C. ± 15 ° C.).

  Further, in the present invention, “solid particulate” means solid and particulate. Further, in the present invention, “enclosure” means being contained inside without overflowing to the outside. Therefore, the lubricating liquid according to the present invention only needs to be contained in the solid particle main body, and it does not matter how the lubricating liquid is contained in the main body. For example, the lubricating liquid may penetrate entirely into the main body, or the lubricating liquid may be filled into the shell-shaped main body. Moreover, although the mold release agent of the present invention includes a lubricating liquid, since the lubricating liquid is contained in the solid particle main body, the form in use is a powder form. That is, the release agent of the present invention is a powder release agent.

  In this case, the main body portion may be made of an organic compound that melts or decomposes at the heating temperature of the casting mold. That is, the powder release agent includes main component particles having a lubricating liquid having a lubricity and being in a liquid state at room temperature, and a main body portion that is formed into solid particles at room temperature and encloses the lubricating liquid. The part may be composed of an organic compound that melts or decomposes at the heating temperature of the casting mold. According to this, when a powder release agent is applied to the cavity wall surface of the heated casting mold, the organic compound constituting the main body part of the main component particles is melted or decomposed by the heat of the cavity wall surface. That is, the main body is melted or decomposed by the heat of the cavity wall surface. When the main body is melted or decomposed, the lubricating liquid contained in the main body is discharged from the main body to the outside. The released lubricating liquid is spread on the cavity wall surface, so that the cavity wall surface is covered with the lubricating liquid. The lubricating liquid covering the cavity wall surface is interposed between the molten metal poured into the cavity and the cavity wall surface. For this reason, the direct contact between the molten metal and the cavity wall surface is prevented, and the occurrence of seizure due to the direct contact between the both is prevented. In this case, the lubricating liquid is preferably a liquid that enhances seizure resistance (releasing properties), and particularly a modified silicone oil.

  In the above, the “heating temperature of the casting mold” means the temperature of the casting mold when the mold release agent is applied to the cavity wall surface, more specifically, the cavity when the mold release agent is applied to the cavity wall surface. It is the temperature of the wall. Generally, the casting mold is set to a predetermined temperature when the release agent is applied to the cavity wall surface. Therefore, the “heating temperature of the casting mold” may be a set temperature of the casting mold. The heating temperature (set temperature) of such a casting mold varies depending on the material of the casting mold used, the material of the metal poured into the casting mold, the manufacturing conditions, and the like. Therefore, although heating temperature cannot be defined uniformly, generally, it is 100 degreeC or more and 400 degrees C or less.

  Further, in this case, the organic compound constituting the main body is preferably melted at the heating temperature of the casting mold. That is, the melting point of the organic compound constituting the main body is preferably higher than normal temperature and lower than the heating temperature of the casting mold. According to this, when the powder release agent is applied to the cavity wall surface, the main body is melted by the heat of the casting mold to be in a liquid state. For this reason, when pouring the molten metal into the cavity, all the main component particles constituting the powder release agent are in a liquid state, and the solid state release agent component does not remain in the cavity. Therefore, the solid state release agent residue is effectively prevented from adhering to the casting. That is, adhesion resistance is improved.

  Moreover, when the organic compound which comprises a main-body part decomposes | disassembles at the heating temperature of a casting mold, it is good that a decomposition product is gas. According to this, the gas produced | generated when the main-body part decompose | disassembled with the heat | fever of a casting mold is discharge | released from a cavity before pouring of the molten metal to a cavity. For this reason, when pouring the molten metal into the cavity, the main body portion hardly remains on the cavity wall surface. Therefore, it is prevented as much as possible that the solid release agent residue adheres to the casting. That is, adhesion resistance is improved.

  Moreover, the organic compound which comprises a main-body part may be decomposed | disassembled into gas with the heat | fever of the molten metal poured into a cavity, after fuse | melting with the heat | fever of a casting mold. According to this, the main body is decomposed into a gas such as carbon dioxide by the heat of the molten metal poured into the cavity. For this reason, after pouring the molten metal into the cavity, most of the components (main body part and lubricating liquid) constituting the powder release agent are in a gas state or a liquid state and are present in the cavity. The amount of the release agent component in the solid state is extremely small. Therefore, it is prevented as much as possible that the solid release agent residue adheres to the casting. That is, adhesion resistance is improved.

  Furthermore, in this case, the molecular weight of the organic compound constituting the main body is preferably 800 or more and 2000 or less. A low molecular weight organic compound having a molecular weight of 800 or more and 2000 or less has a low melting point. Therefore, by constituting the main body portion with such a low molecular weight organic compound, the main body portion can be melted by the heat of the casting mold.

  Furthermore, in this case, the organic compound constituting the main body is preferably polyethylene wax or polypropylene wax. The melting point of polyethylene wax or polypropylene wax is about 90 ° C. to 120 ° C., which is lower than the general heating temperature (set temperature) of most casting molds. Therefore, by configuring the main body using these, the main body can be reliably melted by the heat of the casting mold.

  Moreover, the powder mold release agent which concerns on this invention may be provided with the binder which is formed in solid particle form at normal temperature, and fuse | melts at the heating temperature of a casting mold. This binder has a function of adhering main component particles to the cavity wall surface by melting and exhibiting adhesive force when applied to the cavity wall surface. That is, the main component particles are attached to the cavity wall surface via the binder.

  In this case, the main body is formed in a shell shape so as to seal the lubricating liquid inside, and is destroyed or poured by the pouring pressure when the molten metal is poured into the casting mold. It is good to be comprised with the organic compound decomposed | disassembled at the temperature of a molten metal. That is, the powder mold release agent comprises a lubricating liquid having a lubricity and in a liquid state at room temperature, and a main body formed in a shell shape so as to seal the lubricating liquid while being formed into solid particles at room temperature. The main component particles having a binder that is formed into solid particles at room temperature and melts at the heating temperature of the casting mold, and the binder melts and exerts adhesive force when applied to the cavity wall surface. The main body particles have the function of adhering the main component particles to the cavity wall surface, and the main body part is decomposed at the temperature of the molten metal that is broken or poured by the pouring pressure when the molten metal is poured into the casting mold. It is good that it is composed of an organic compound that is (that is, decomposed by the heat of the molten metal). In this case, the main body may be configured so that the sealed state of the lubricating liquid sealed inside is maintained until the molten metal is poured into the cavity. For example, the organic compound constituting the main body may be an organic compound that does not melt and decompose depending on the heating temperature of the casting mold.

  According to this, when the powder mold release agent is applied to the cavity wall surface of the heated casting mold, the binder melts and exhibits adhesive force, thereby allowing the powder mold release agent to pass through the binder. The main component particles are uniformly attached to the cavity wall surface. Then, the main body part of the main component particles is destroyed by the pouring pressure when the molten metal is poured into the cavity thereafter, or the main body part of the main component particles is decomposed by the heat of the molten metal to be poured. . When the main body is broken or disassembled, the lubricating liquid sealed inside the shell-shaped main body elutes to the outside, and the eluted lubricating liquid spreads on the cavity wall surface and the molten metal. It is interposed between the cavity walls. For this reason, the direct contact between the molten metal and the cavity wall surface is prevented, and the occurrence of seizure due to the direct contact between both is prevented. In this case, the lubricating liquid is preferably a liquid that enhances seizure resistance (releasing properties), and particularly a modified silicone oil.

  Moreover, the shell-shaped main body part is good to be comprised with the melamine resin. By constituting the shell-shaped main body portion with a relatively high strength melamine resin, when the main component particles are attached to the cavity wall surface through the binder, the sealed state of the lubricating liquid in the main body portion can be maintained. . When the molten metal is poured into the cavity, the shell-shaped main body made of melamine resin is decomposed or destroyed by the molten metal pressure due to the heat of the molten metal. For this reason, the lubricating liquid sealed inside the main body can be eluted to the outside.

  The binder may be an organic compound having a molecular weight of 500 or more and 30000 or less. When the molecular weight of the binder, which is an organic compound, is within the above range, the binder can be melted by the heating temperature of a commonly used casting mold, and by exhibiting appropriate adhesiveness on the cavity wall surface, The component particles can be sufficiently adhered. In this case, the binder may include polyethylene wax or polypropylene wax. When the binder is polyethylene wax or polypropylene wax, the above-described effects are remarkably realized.

  The average particle diameter of the main component particles, specifically, the volume average particle diameter is preferably 1 μm or more and 100 μm or less. When the average particle diameter (volume average particle diameter) of the main component particles is within the above-mentioned range, a sufficient amount of the main component particles are adhered to the cavity wall surface when the powder release agent is applied, and the dispersibility is uniform. Further, when the lubricating liquid is eluted, a sufficient amount of the lubricating liquid can be spread on the cavity wall surface.

  The present invention also relates to a method for producing a powder release agent that is applied to the cavity wall surface of a heated casting mold, and is an organic material that is in a solid state at room temperature and melts or decomposes at the heating temperature of the casting mold. A mixed liquid is prepared by mixing the first step of producing an organic compound in a liquid state by heating the compound, the organic compound in a liquid state, and a lubricating liquid composed of a liquid having lubricity. The second step to be prepared and spraying the liquid mixture to form liquid droplets of the liquid mixture and solidifying the organic compound in the formed liquid droplets to form solid particles at room temperature. And a third step of producing a powder mold release agent comprising main component particles having a main body part and a lubricating liquid contained in the main body part. In this case, the lubricating liquid is preferably a modified silicone oil. The molecular weight of the organic compound is preferably 800 or more and 2000 or less. Preferably, the organic compound is polyethylene wax or polypropylene wax.

  According to the present invention, in the first step, a liquid material of an organic compound that is in a solid state at room temperature and melts or decomposes at the heating temperature of the casting mold is produced. In the subsequent second step, a mixed liquid in which a liquid material of an organic compound and a lubricating liquid are mixed is prepared. In the third step, the liquid mixture is sprayed to form liquid droplets of the liquid mixture, and the organic compound in the formed liquid droplets is solidified. At this time, the lubricating liquid is taken into the solidified organic compound, whereby a powder release agent including the main component particles according to the present invention is generated. That is, in the third step, the powder release agent according to the present invention is generated by spray granulation. According to this, the powder mold release agent which has high seizure resistance can be manufactured.

It is typical sectional drawing which shows one structural example of the powder mold release agent which concerns on 1st embodiment. It is typical sectional drawing which shows the other structural example of the powder mold release agent which concerns on 1st embodiment. It is typical sectional drawing which shows the other structural example of the powder mold release agent which concerns on 1st embodiment. It is a figure which shows schematic structure of a spray cool apparatus. It is typical sectional drawing which shows the structural example of the powder mold release agent which concerns on 2nd embodiment. It is a figure which shows the state by which the powder mold release agent which concerns on 2nd embodiment was apply | coated to the cavity wall surface of the heated casting metal mold | die. It is a graph which shows mold release resistance at the time of using the powder mold release agent which concerns on an Example and a comparative example. It is the graph which compared the black area ratio computed in the Example and the comparative example. It is the graph which compared the average weight difference computed in the Example and the comparative example.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described. The powder release agent according to the first embodiment includes a lubricating liquid having a lubricity and a liquid state at room temperature, and an organic compound that is formed into solid particles at room temperature and melts or decomposes at the heating temperature of the casting mold. The main component particles are configured and have a main body portion containing a lubricating liquid. FIG. 1 is a schematic cross-sectional view showing an example of the structure of main component particles according to the first embodiment. As shown in FIG. 1, the main component particles 1 provided in the powder release agent according to the first embodiment have a main body 2 and a lubricating liquid 3. In FIG. 1 and FIGS. 2 and 3 to be described later, the lubricating liquid 3 is indicated by dots.

  The main body 2 is in a solid state at room temperature and in a granular form, that is, in the form of solid particles at room temperature. The main body 2 is made of an organic compound that melts or decomposes at the heating temperature of the casting mold.

  The lubricating liquid 3 has lubricity and is in a liquid state at room temperature. The lubricating liquid 3 should be a liquid that enhances the seizure resistance (release property) when it is used as a release agent. The lubricating liquid 3 may be composed of what is usually used as a raw material for the liquid release agent. The lubricating liquid 3 is preferably a modified silicone oil. This lubricating liquid 3 is contained in the main body 2 formed in the form of solid particles. According to FIG. 1, the lubricating liquid 3 penetrates entirely inside the solid particulate main body 2.

  The lubricating liquid 3 may be included in the main body 2 in a form other than that shown in FIG. For example, as shown in FIG. 2, the lubricating liquid 3 may be filled in the main body 2 formed in a hollow shape. Further, as shown in FIG. 3, a large number of holes may be formed in the main body 2, and the lubricating liquid 3 may be filled in the holes.

  The main component particles 1 are applied as a main component of the powder release agent to the cavity wall surface of the casting mold heated to a preset temperature. At the time of application, the main component particles 1 are solid particles. Since the main body 2 of the applied main component particles 1 is made of an organic compound that melts or decomposes at the heating temperature of the casting mold, it is melted or decomposed by heat from the cavity wall surface of the casting mold. When the main body 2 is melted or decomposed, the lubricating liquid 3 contained in the main body 2 oozes out from the main body 2 and is eluted outside the main body 2. The eluted lubricating liquid 3 is spread on the cavity wall surface. In this way, the cavity wall surface is covered with the lubricating liquid 3, and a release film made of the lubricating liquid is formed on the cavity wall surface.

  After the powder release agent having the main component particles 1 is applied to the cavity wall surface of the casting mold, the molten metal is poured into the cavity. Since the cavity wall surface is covered with the lubricating liquid 3 eluted from the main body 2 as described above, when the molten metal is poured into the cavity, the lubricating liquid 3 is interposed between the molten metal and the cavity wall surface. To do. Therefore, direct contact between the molten metal and the cavity wall surface is prevented. Therefore, the casting formed in the cavity is prevented from being seized on the cavity wall surface. In particular, when the lubricating liquid 3 is a modified silicone oil, high seizure resistance equivalent to that of the modified silicone water-soluble release agent is exhibited.

  Moreover, since the powder mold release agent according to the first embodiment does not contain moisture, a cast hole due to water remaining on the cavity wall surface does not occur in the cast product. In addition, defects caused by using water-soluble mold release agents, such as deterioration of casting mold due to thermal shock during coating, increase in equipment costs for wastewater treatment facilities, deterioration of working environment due to generation of mist, etc. Does not occur. That is, the powder mold release agent according to the first embodiment exhibits high seizure resistance equivalent to that of the water-soluble mold release agent, and is a highly useful powder that has overcome the disadvantages of the water-soluble mold release agent. It is a mold release agent.

  In addition, when the melting point of the organic compound constituting the main body part 2 of the main component particle 1 is equal to or lower than the heating temperature of the casting mold, the main body part 2 is melted when the powder release agent is applied to the cavity wall surface. It is made into a liquid state. For this reason, when the molten metal is poured into the cavity, the components (main body part 2 and lubricating liquid 3) constituting the main component particles 1 of the powder release agent are all in a liquid state and are in a solid state. No release agent component remains in the cavity. Therefore, it is prevented that the solid release agent residue adheres to the cast product. That is, adhesion resistance is improved.

  Moreover, the temperature of the molten metal poured into the cavity after the application of the powder release agent is, for example, about 650 ° C. when the molten metal is a molten aluminum. When such a high-temperature molten metal comes into contact with the main component particles 1 of the powder release agent, the organic compound constituting the main body 2 is almost decomposed by heat. The decomposition product is a gas such as carbon dioxide. Therefore, after pouring the molten metal into the cavity, most of the components (the main body 2 and the lubricating liquid 3) constituting the powder release agent are in a gas state or a liquid state (that is, a phase state other than the solid state). Therefore, the amount of the solid state release agent component existing in the cavity is extremely small. Therefore, it is prevented as much as possible that the solid release agent residue adheres to the casting. That is, adhesion resistance is improved.

  Moreover, when the organic compound which comprises the main-body part 2 is decomposed | disassembled into gas by the heating temperature of a casting mold, the gas produced | generated by decomposition | disassembly reaction is discharge | released from a cavity. For this reason, when pouring the molten metal into the cavity, the main body portion hardly remains on the cavity wall surface. Therefore, it is prevented as much as possible that the solid release agent residue adheres to the casting. That is, adhesion resistance is improved.

  The molecular weight of the organic compound that constitutes the main body 2 is preferably 10,000 or less. In particular, the molecular weight is preferably 800 or more and 2000 or less. An organic compound having a molecular weight in the above range melts at a general mold heating temperature (90 ° C. to 150 ° C.) and is easily decomposed into a gas at a higher temperature. The molecular weight of polyethylene wax and polypropylene wax is about 800 to 2000, and the melting point is about 90 ° C to 150 ° C. Therefore, it is preferable to use these as organic compounds constituting the main body 2.

  Next, the manufacturing method of the powder release agent which concerns on this embodiment is demonstrated. First, an organic compound that is in a liquid state is manufactured by heating an organic compound that is in a solid state at room temperature and melts or decomposes at a heating temperature of the casting mold (first step). Subsequently, the organic compound in a liquid state and a lubricating liquid composed of a liquid having lubricity are mixed and stirred using a mixer. At this time, the lubricating liquid may be heated so that the temperature of the lubricating liquid is approximately the same as the temperature of the organic compound in the liquid state. Thereby, the liquid mixture with which the liquid state organic compound and the lubricating liquid were mixed is prepared (2nd process). Thereafter, the mixed liquid is supplied to a spray cool device (a spray cooling granulator), and a powder release agent in the form of solid particles at normal temperature is generated by a spray granulation method.

  FIG. 4 is a diagram showing a schematic configuration of the spray cooler 10. As shown in FIG. 4, the spray cooler 10 includes a granulation tower 11 and an atomizer 12. The granulation tower 11 is connected to a side peripheral portion 11a formed in a cylindrical shape having an axis along the vertical direction, a top plate portion 11b that closes an upper end opening of the side peripheral portion 11a, and a lower end of the side peripheral portion 11a. And a recovery unit 11c. The recovery part 11c is formed in a tapered shape that tapers downward, and a recovery passage 13 is connected to the lower end portion thereof. An internal space of the granulation tower 11 is formed by the space surrounded by the side peripheral portion 11a, the top plate portion 11b, and the recovery portion 11c.

  The atomizer 12 includes a cylindrical container 12a and a rotating body 12b. The cylindrical container 12a penetrates the top plate portion 11b vertically, and its upper end is located outside the granulation tower 11 and its lower end is located in the internal space of the granulation tower 11. A rotating body 12b is attached to the lower end of the cylindrical container 12a. Accordingly, the rotating body 12b is disposed in the internal space of the granulation tower 11. The rotating body 12b is configured to rotate around the vertical axis in the internal space of the granulation tower 11. A hollow space is formed inside the rotating body 12b, and the hollow space communicates with the space in the cylindrical container 12a. In addition, a large number of fine holes communicating with the internal hollow space are opened on the side peripheral surface of the rotating body 12b.

  The operation of the spray cooler 10 having the above configuration will be described. First, the rotating body 12b of the atomizer 12 is rotated. Next, the mixed liquid obtained in the second step is supplied from the upper end of the cylindrical container 12a of the atomizer 12 into the cylindrical container 12a. The mixed liquid supplied into the cylindrical container 12a is guided from the cylindrical container 12a into the rotating body 12b. The liquid mixture in the rotator 12b is ejected from a number of fine holes opened on the side peripheral surface of the rotator 12b by centrifugal force. In this way, the mixed liquid is sprayed from the atomizer 12.

  The mixed liquid sprayed from the atomizer 12 becomes very fine droplets and falls downward in the internal space of the granulation tower 11 by gravity. When the droplet is cooled during the fall, the organic compound in the droplet is solidified into a granular shape. On the other hand, the lubricating liquid in the droplets is taken into the solidified organic compound. In this way, the liquid mixture obtained in the second step is spray-cooled and granulated, so that the solid particulate main body 2 composed of an organic compound, and the lubricating liquid 3 contained in the main body 2 are provided. A powder release agent including the main component particles 1 having the above is generated (third step). The generated powder release agent is discharged from the collection passage 13 to the outside of the spray cooler 10.

  Thus, the powder release agent which concerns on 1st embodiment is manufactured through a 1st process, a 2nd process, and a 3rd process.

(Second embodiment)
Next, the powder release agent according to the second embodiment will be described. The powder release agent according to the second embodiment has a lubricity and a liquid that is in a liquid state at room temperature, and is formed into a solid particle at room temperature and is formed in a shell shape so as to seal the lubricating liquid. The main component particles having the outer shell material as the main body portion and a binder that is formed into solid particles at room temperature and melts at the heating temperature of the casting mold.

  FIG. 5 is a schematic cross-sectional view showing a structural example of main component particles according to the second embodiment. As shown in FIG. 5, the main component particles 4 according to the second embodiment include an outer shell material 5 (main body portion) and a lubricating liquid 6.

  The outer shell material 5 is not melted and decomposed at the heating temperature of the casting mold, and is destroyed by the pouring pressure when the molten metal is poured into the casting mold, or the molten shell material 5 It is composed of an organic compound that thermally decomposes at a temperature (that is, decomposed by the heat of the molten metal). As an organic compound having such characteristics, a melamine resin can be exemplified.

  Like the lubricating liquid 3 according to the first embodiment, the lubricating liquid 6 has lubricity and is in a liquid state at room temperature. Further, the lubricating liquid 3 is preferably a liquid that enhances the seizure resistance (release property) when it is used as a release agent. The lubricating liquid 3 may be composed of what is usually used as a raw material for the liquid release agent. The lubricating liquid 3 is preferably a modified silicone oil.

  As can be seen from FIG. 5, the outer shell material 5 is formed in a shell shape so as to seal the lubricating liquid 6 inside. Therefore, at the normal temperature, the main component particles 4 are in the form of a powder whose outer surface is covered with the outer shell material 5. Thus, by enclosing the lubricating liquid inside the shell-like outer shell material 5, the content of the lubricating liquid 6 in one main component particle 4 can be increased.

  Moreover, the binder with which the powder mold release agent which concerns on 2nd embodiment is equipped is comprised by the substance which is formed in solid particle form at normal temperature, and fuse | melts at the heating temperature of a casting mold. This binder has a function of adhering the main component particles 4 to the cavity wall surface by melting and exerting adhesive force when applied to the cavity wall surface.

  FIG. 6 is a view showing a state where the powder release agent according to the second embodiment is applied to the cavity wall surface of a heated casting mold. As shown in FIG. 6, among the powder release agent applied to the cavity wall surface H, the binder 7 is melted by the heat from the cavity wall surface H. The melted binder 7 is stretched on the cavity wall surface H. Of the powder release agent applied to the cavity wall surface H, the main component particles 4 are retained in the binder 7 by the adhesive force of the melted binder 7. For this reason, the main component particles 4 are uniformly dispersed in the binder 7.

  The binder is preferably an organic compound having a molecular weight of 500 or more and 30000 or less. When the molecular weight of the organic compound used as the binder is within the above range, the binder can be melted by the heating temperature of a commonly used casting mold, and by exhibiting appropriate adhesiveness on the cavity wall surface, The main component particles can be sufficiently adhered. In this case, the binder may include polyethylene wax or polypropylene wax. When the binder is polyethylene wax or polypropylene wax, the above-described effects are remarkably realized.

  The average particle diameter (volume average particle diameter) of the main component particles 4 is preferably 1 μm or more and 100 μm or less. If the average particle diameter of the main component particles 4 is larger than the above range, the main component particles interfere with each other, so that the uniform dispersibility of the main component particles is deteriorated when the powder release agent is applied to the cavity wall surface. And the adhesion of the main component particles to the cavity wall surface deteriorates. If the average particle diameter of the main component particles 4 is smaller than the above range, the content ratio of the lubricating liquid with respect to the main body portion is relatively small, so that the lubricating liquid cannot be sufficiently spread on the cavity wall surface and is separated. There is a risk that moldability and seizure resistance will deteriorate. On the other hand, when the average particle diameter of the main component particles 4 is within the above-described range, a sufficient amount of the main component particles are adhered to the cavity wall surface during the application of the powder release agent and are uniformly dispersible. Further, when the lubricating liquid is eluted, a sufficient amount of the lubricating liquid can be spread on the cavity wall surface.

  After the powder release agent according to the second embodiment is applied to the cavity wall surface of the casting mold, the molten metal is poured into the cavity. Since the main component particles 4 are attached to the cavity wall surface through the binder 7 as described above, when the molten metal is poured into the cavity, the main component particles 4 are subjected to pressure (pouring pressure) from the molten metal. Act on. The main component particles 4 are heated by the heat of the molten metal. Here, as described above, the outer shell material 5 (main body part) of the main component particles 4 is formed of an organic compound that is broken by the pouring pressure or decomposes at the temperature of the molten metal. Therefore, when the molten metal is poured into the cavity, the outer shell material 5 is broken or decomposed. When the outer shell material 5 is broken or decomposed, the lubricating liquid 6 sealed inside the outer shell material 5 is eluted. The lubricating liquid 6 thus eluted spreads on the cavity wall surface and is interposed between the molten metal and the cavity wall surface to prevent direct contact between the cavity wall surface and the molten metal. For this reason, the casting formed in the cavity is prevented from being seized on the cavity wall surface. In this case, when the lubricating liquid 6 is a modified silicone oil, high seizure resistance equivalent to that of the modified silicone water-soluble release agent is exhibited.

  In addition, since the powder mold release agent according to the second embodiment does not contain moisture, a cast hole due to water remaining on the cavity wall surface does not occur in the cast product. In addition, defects caused by using water-soluble mold release agents, such as deterioration of casting mold due to thermal shock during coating, increase in equipment costs for wastewater treatment facilities, deterioration of working environment due to generation of mist, etc. Does not occur. That is, the powder release agent according to the second embodiment also exhibits high seizure resistance equivalent to that of the water-soluble release agent, as well as the water-solubility, like the powder release agent according to the first embodiment. It is a highly useful powder release agent that overcomes the disadvantages of release agents.

Example 1
In Example 1, the powder release agent according to the first embodiment is manufactured. In producing the powder release agent according to the first embodiment, first, polyethylene wax (made by Mitsui Chemicals, molecular weight: 900, melting point: 116 ° C.) as an organic compound constituting the main body is heated to 140 ° C. Thus, a polyethylene wax in a liquid state was produced. Next, a polyethylene wax in a liquid state heated to 140 ° C. and a long-chain alkyl-modified type modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd.) as a lubricating liquid heated to 140 ° C. are used in a weight ratio of 1 : 9 (silicone oil: polyethylene wax = 1: 9) to prepare a mixed solution. Next, the mixture was stirred for 15 minutes using a homomixer while maintaining the temperature of the mixture at 140 ° C.

  Then, the said liquid mixture was supplied to the spray cool apparatus (Okawara processing machine Co., Ltd. make, brand name: L-8i), and the liquid mixture was spray-cooled. The rotation speed of the atomizer at this time is 3500 r. p. m. Further, when the temperature of the atomizer (rotating body) is T1, and the outlet temperature in the granulation tower is T2, the temperature of the atomizer and the temperature in the granulation tower are controlled so that T1 <T2. Fine droplets made of a mixture sprayed from an atomizer are cooled and solidified in a granulation tower to form solid particles. Thus, in Example 1 including main body particles having a solid particle-shaped main body portion made of polyethylene wax and liquid modified silicone oil (lubricating liquid) contained in the main body portion so as to penetrate into the main body portion. Such a powder release agent was produced.

  It was 53 micrometers when the weight average particle diameter of the main component particle | grains of the powder mold release agent which concerns on manufactured Example 1 was measured with the optical diffraction / scattering apparatus. Moreover, when the weight ratio of the modified silicone oil and polyethylene contained in the main component particles of the produced powder release agent according to Example 1 was measured with a solid NMR measuring apparatus, modified silicone oil: polyethylene = 14: 86. Met. That is, the content of the modified silicone oil (lubricant) was 14 wt%.

(Example 2)
In Example 2, the powder release agent according to the second embodiment is prepared. In this case, first, a modified silicone oil as a lubricating liquid is added to an ethylene-maleic anhydride copolymer that is a dispersion medium and stirred. Thereby, a lot of fine oil droplets of modified silicone oil are formed in the dispersion medium. Next, melamine-formalin prepolymer and acetic acid are added to the dispersion medium to adjust pH and temperature. Here, the oil droplet surface is hydrophobic (lipophilic), and the melamine-formalin prepolymer is polymerized on the oil droplet surface. And the melamine polymer (melamine resin) produced by the polymerization reaction is formed in a film shape so as to cover the oil droplet surface. In this way, a shell-like outer shell material (main body portion) made of melamine resin is formed, and the modified silicone oil (lubricating liquid) is sealed inside the outer shell material.

  Next, the dispersion medium is volatilized by drying, and main component particles having a shell-like outer shell material (main body portion) and a modified silicone oil (lubricating liquid) sealed inside the outer shell material are extracted. Thereafter, the extracted main component particles and polypropylene wax powder as a binder are mixed in a ratio of main component particles: binder = 80 wt%: 20 wt%. Thus, the powder release agent which concerns on Example 2 was manufactured.

  It was 17 micrometers when the weight average particle diameter of the main component particle | grains of the powder mold release agent which concerns on manufactured Example 2 was measured with the optical diffraction / scattering apparatus. Moreover, it was 75 wt% when the content rate of the modified silicone oil contained in the main component particles of the produced powder release agent according to Example 2 was measured by ICP-OES analysis.

(Release resistance evaluation)
Next, the release resistance of the powder release agent according to Examples 1 and 2 was measured. In measuring the mold release resistance, the test casting mold was set in a die casting machine having a clamping force of 800 t. And the powder mold release agent which concerns on each example was apply | coated to the cavity wall surface of the casting mold for a test using the coating device, respectively. The coating amount at this time is 2.0 g, and the coating time is 2 seconds. The mold was clamped after application of the powder releasing agent, and molten aluminum (material type: ADC12) heated to a temperature of 660 ° C. was injected into the cavity of the test casting mold and cast. The test casting mold was opened after the lapse of a predetermined time. The magnitude of the force required at that time was measured, and the mold release resistance (unit: MPa) was measured by converting the measured force into pressure. Such measurement of mold release resistance was performed 30 times per powder mold release agent according to one example, and an average value of mold release resistance was obtained. Further, as Comparative Example 1, casting molding was performed as described above using a graphite-based powder release agent, and an average value of mold release resistance at the time of mold opening was obtained.

  FIG. 7 is a graph showing the release resistance when the powder release agent according to each example (Example 1, Example 2, Comparative Example 1) is used. As can be seen from FIG. 7, the average value of the release resistance when the powder release agent according to Example 1 is used is about 2.8 MPa, and the case where the powder release agent according to Example 2 is used. The average value of the mold release resistance was about 2.3 MPa, and the average value of the mold release resistance when the graphite-based powder mold release agent according to Comparative Example 1 was used was about 3.2 MPa. From this, it can be seen that the powder release agent according to Example 1 and Example 2 is superior to the conventional powder release agent. Further, the release resistance when the powder release agent according to Example 2 is used is smaller than the release resistance when the powder release agent according to Example 1 is used. This is because the content of the lubricating liquid in the main component particles of the powder release agent according to Example 2 is higher than the content of the lubricating liquid in the main particles of the powder release agent according to Example 1. This is probably due to the large size.

(Evaluation of adhesion resistance)
Next, the adhesion resistance of the powder release agent according to Example 1 and Example 2 was evaluated. In evaluating the adhesion resistance, first, an iron cup having a diameter of 30 mm was prepared. This iron cup corresponds to a casting mold. The iron cup was heated to 200 ° C., and the powder release agent according to the example was spread on the bottom of the heated iron cup. Thereafter, an iron cup was filled with a molten aluminum alloy (material type: ADC12) at a temperature of 650 ° C. The weight of the molten aluminum alloy was 60 g.

  Next, the molten aluminum alloy filled in the iron cup was naturally cooled, and the aluminum alloy was solidified in the iron cup. Thereafter, the solidified aluminum alloy was taken out from the iron cup. And how much solid state release agent residue adhered to the surface that was in contact with the powder release agent according to each example that was spread on the bottom surface of the aluminum alloy, that is, the bottom surface of the iron cup Was evaluated. Here, the release agent residue is black. Therefore, the ratio of the area of the black portion to the area of the bottom surface of the aluminum alloy was calculated as the black area ratio, and this black area ratio was used as an evaluation index for adhesion resistance. As the black area ratio is smaller, it can be evaluated that the solid mold release agent residue does not adhere to the cast product and the adhesion resistance is higher. Further, as Comparative Example 2, the black area ratio when a graphite-based powder release agent was used was calculated, and as Comparative Example 3, the black area ratio when a fatty acid-based powder release agent was used was calculated.

  FIG. 8 is a graph comparing the black area ratios calculated in Example 1, Example 2, Comparative Example 2, and Comparative Example 3. As shown in FIG. 8, the black area ratio is 0 when the powder release agent according to Example 1 and Example 2 is used. That is, the solid release agent residue did not adhere to the casting. On the other hand, the black area ratio when the graphite-based powder release agent was used was 5%, and the black area ratio when the fatty acid-based powder release agent was used was 0.5%. From this result, it can be seen that the adhesion resistance of the powder release agent according to Example 1 and Example 2 is very high.

(Evaluation of seizure resistance)
Next, the seizure resistance of the powder release agent according to Example 1 and Example 2 was evaluated. In evaluating the seizure resistance, first, the powder release agent according to each example was applied to the surface of a core pin previously heated to a predetermined temperature provided in a die casting mold. The application amount is 0.2 g, and the application time is 2 seconds. Thereafter, a molten aluminum alloy (material type: ADC12) (temperature: 660 ° C.) was injected into the cavity of the die casting mold, and the core pin was cast with the molten aluminum alloy. Subsequently, the aluminum alloy in the cavity was waited until it was cooled and solidified. After the cooling and solidification was completed, the core pin was extracted from the cast product (aluminum alloy), and the weight G1 of the core pin was measured. Next, the cast pin was immersed in an alkaline solution to remove the aluminum alloy adhering to the cast pin. Thereafter, the weight G2 of the core pin was measured again. And weight difference (DELTA) G (G1-G2) of the weight G1 and the weight G2 was computed. The calculated weight difference ΔG is the weight of the aluminum alloy attached to the core pin, that is, the weight of the cast product seized on the cavity wall surface (the wall surface of the core pin). Such measurement of the weight difference ΔG was repeated 20 times, and the average value was calculated as the average weight difference ΔGav. It can be evaluated that the smaller the average weight difference ΔGav is, the smaller the amount of cast product seized on the cavity wall surface (the wall surface of the core pin), and the higher the seizure resistance. Further, as Comparative Example 4, the average weight difference ΔGav when a graphite-based powder release agent was used, and as Comparative Example 5, the average weight difference ΔGav when a modified silicone-based water-soluble release agent was used, respectively. Calculated.

  FIG. 9 is a graph comparing the average weight difference ΔGav calculated in Example 1, Example 2, Comparative Example 4, and Comparative Example 5. As shown in FIG. 9, the average weight difference ΔGav when the powder release agent according to Example 1 is used is 5.2 mg, and the average weight difference ΔGav when the powder release agent according to Example 2 is used. Is 3.5 mg, the average weight difference ΔGav when the graphite-based powder release agent according to Comparative Example 4 is used is 8.8 mg, and the weight when the modified silicone-based water-soluble release agent according to Comparative Example 5 is used. The difference ΔGav was 5.2 mg. From this result, it can be seen that the powder release agent according to Example 1 is comparable to the seizure resistance of the modified silicone-based water-soluble release agent and exhibits high seizure resistance. Moreover, the seizure resistance of the powder release agent according to Example 2 is superior to the seizure resistance of the modified silicone-based water-soluble release agent. For this reason, it turns out that the powder mold release agent which concerns on Example 2 exhibits extremely excellent seizure resistance.

  Although various embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and examples. For example, in the first embodiment, the example in which the powder release agent according to the present invention is generated by the spray cooling method using the spray cool device in the third step is shown. The powder release agent according to the present invention can also be produced by a drying method. In the first embodiment, an example in which polyethylene wax is used as the organic compound constituting the main body is shown. However, polypropylene wax may be used, or other organic compound having a relatively low molecular weight may be used. May be. Further, in the second embodiment, the outer shell material as the main body is formed of melamine resin, but it is destroyed by the pouring pressure at the time of pouring the molten metal, or by the heat of the molten metal to be poured. As long as the organic compound is decomposed, the outer shell material may be formed of a material other than the melamine resin. Thus, the present invention can be modified without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 ... Main component particle, 2 ... Main part, 3 ... Lubricating liquid, 4 ... Main component particle, 5 ... Outer shell substance (main part), 6 ... Lubricating liquid, 7 ... Binder, 10 ... Spray cool apparatus, 11 ... Manufacturing Granule tower, 11a ... side peripheral part, 11b ... top plate part, 11c ... collection part, 12 ... atomizer, 12a ... cylindrical container, 12b ... rotating body, 13 ... collection passage

Claims (12)

A powder release agent applied to the cavity wall surface of a heated casting mold,
The main component particles having a lubricating property and having a lubricating liquid in a liquid state at normal temperature, and a main body part that is formed into solid particles at normal temperature and contains the lubricating liquid,
The main body portion is configured such that when the main component particles come into contact with the molten metal poured into the cavity of the casting mold, the contained lubricant is eluted to the outside. Mold. In the powder release agent according to claim 1,
A powder mold release agent, wherein the main body is composed of an organic compound that melts or decomposes at the heating temperature of the casting mold. In the powder release agent according to claim 2,
A powder release agent, wherein the lubricating liquid is a modified silicone oil. In the powder release agent according to claim 2 or 3,
The powder mold release agent whose molecular weight of the organic compound which comprises the said main-body part is 800 or more and 2000 or less. In the powder release agent according to any one of claims 2 to 4,
The powder mold release agent in which the organic compound which comprises the said main-body part contains a polyethylene wax or a polypropylene wax. In the powder release agent according to claim 1,
It is formed into solid particles at room temperature, and includes a binder that melts at the heating temperature of the casting mold,
The binder has a function of adhering the main component particles to the cavity wall surface by melting and exerting adhesive force when applied to the cavity wall surface;
The main body is formed in a shell shape so as to seal the lubricating liquid inside, and is destroyed or poured by a pouring pressure when a molten metal is poured into the casting mold. Powder release agent composed of an organic compound that decomposes at the temperature of the molten metal. In the powder release agent according to claim 6,
A powder release agent, wherein the lubricating liquid is a modified silicone oil. In the powder release agent according to claim 6 or 7,
The powder mold release agent in which the said main-body part is comprised with a melamine resin. In the powder release agent according to any one of claims 6 to 8,
The binder is a powder release agent, which is an organic compound having a molecular weight of 500 or more and 30000 or less. The powder release agent according to any one of claims 6 to 9,
A powder release agent, wherein the binder comprises polyethylene wax or polypropylene wax. In the powder release agent according to any one of claims 6 to 10,
The powder mold release agent whose average particle diameter of the said main component particle | grain is 1 micrometer or more and 100 micrometers or less. A method for producing a powder release agent applied to a cavity wall surface of a heated casting mold,
A first step of producing the organic compound in a liquid state by heating an organic compound that is in a solid state at room temperature and melts or decomposes at a heating temperature of the casting mold;
A second step of preparing a liquid mixture by mixing the organic compound in a liquid state and a lubricating liquid composed of a liquid having lubricity;
A main body formed of the organic compound and formed into solid particles at room temperature by spraying the liquid mixture to form droplets of the liquid mixture and solidifying the organic compound in the formed liquid droplets And a third step of generating a powder release agent comprising main component particles having the lubricating liquid contained in the main body portion;
A method for producing a powder release agent, comprising:

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