JP5950871B2 - Water-soluble release agent and method for producing water-soluble release agent - Google Patents

Description

  The present invention relates to a water-soluble mold release agent applied to the surface of an aluminum die casting mold member, a manufacturing method thereof, and a manufacturing apparatus.

  High-temperature aluminum melt contacts the cavity surface of the aluminum die-casting die, die-casting pins, inserts, etc. provided in the cavity, so that the molten aluminum that touched reacts on the cavity surface of the die and the surface of the die-casting pin May form. In order to prevent such seizure and improve the releasability, a release agent is applied to the cavity surface, the surface of the die cast pin, etc. before injecting the molten aluminum into the cavity. In recent years, a water-soluble release agent is often used as such a release agent.

Patent Document 1 discloses a water-soluble release agent in which a non-volatile component is prepared so that organopolysiloxane is a main component and sodium oxide and potassium oxide generated upon contact with molten aluminum are suppressed to 2000 ppm or less. To do. According to this, the amount of the release agent and _Na 2 _AlO 3 formed by the reaction of a molten _aluminum, K 2 AlO compounds such ₃ is suppressed. Therefore, it is possible to suppress the roughness of the casting surface due to the adhesion of these to the casting surface of the product, and as a result, the product quality can be improved.

  Patent Document 2 discloses a water-soluble release agent containing aluminum oxide fine particles as an inorganic substance. The aluminum oxide fine particles in the mold release agent improve the heat insulating property of the mold release agent, improve the flow of the molten aluminum in the mold, and reduce defects such as poor casting around the thin casting.

  Patent Document 3 discloses a release agent comprising a colloidal aqueous solution in which nanoparticles of metal oxide other than silicon dioxide are dispersed in water without the addition of a dispersant. According to this, since the metal oxide nanoparticles dispersed in the mold release agent adhere to the cavity surface of the mold, the mold release property can be improved. Further, since such nanoparticles do not gasify even when in contact with a high-temperature molten aluminum, the presence of the nanoparticles does not roughen the casting surface of the product. Therefore, product quality can be improved.

JP-A-4-844633 JP 2001-71092 A JP 2009-226659 A

  Even when the water-soluble release agent described in each of the above patent documents is used, it is not possible to sufficiently suppress seizure on the mold surface. For example, the main component of the water-soluble release agent described in Patent Document 1 is organopolysiloxane, but this main component reacts with the molten aluminum, and the reaction product may be baked on the mold surface. Moreover, although the aluminum oxide fine particles added to the water-soluble release agent described in Patent Document 2 can improve heat insulation, the effect on seizure is small. In addition, the water-soluble release agent described in Patent Document 3 may suppress some seizure due to the metal oxide nanoparticles mixed therein interposed between the mold surface and the molten metal. Since the bonding force between the nanoparticles is weak, it is removed when the molten aluminum is injected. For this reason, image sticking on the mold surface cannot be sufficiently suppressed.

  An object of this invention is to provide the water-soluble mold release agent which can fully suppress seizing, its manufacturing method, and the manufacturing apparatus of such a water-soluble mold release agent.

(Means for solving the problem)
The present invention is a water-soluble mold release agent used for an aluminum die-casting die member, water as a solvent, a silicon compound such as modified silicone uniformly dispersed in water as a solvent, Mg, Ca, Ba, at least one oxide of selected from the group consisting of al, a hydroxide or carbonate, and the second metal compound dissolved in water as the solvent, only including, a second metal compound is MgO or CaCO ₃ And a water-soluble mold release agent in which MgO or CaCO ₃ is dissolved in a saturated state . In this case, the pH of the water-soluble release agent is preferably 8 or more and 11 or less . Et al is, the amount of dissolved MgO or CaCO ₃ in water-soluble release agent is, it is 0.003 g / l or more and may not more than 0.7 g / l.

The present invention also relates to a method for producing a water-soluble mold release agent used for an aluminum die casting mold member, wherein the silicon compound dispersed aqueous solution (aqueous solution in which a silicon compound is dispersed) is supplied into a mold release agent tank. A second metal compound that is at least one oxide, hydroxide, or carbonate selected from the group consisting of Mg, Ca, Ba, and Al is dissolved in the silicon compound-dispersed aqueous solution in the process and the release agent tank a second step, only including, a second metal compound is the MgO or CaCO _3, the second step, by immersing the MgO or solid CaCO ₃ in the silicon compound dispersed in an aqueous solution of the release agent in the tank, the predetermined The method for producing a water-soluble mold release agent, which is a step of dissolving MgO or CaCO ₃ until the dissolved amount of MgO or CaCO ₃ is saturated by being allowed to stand for at least this time , is provided. In this case, in the second step, not good that the pH dissolving the second metal compound to the silicon compound dispersion solution so that the are and at 11 or less than 8.

According to the present invention, it is possible to provide a water-soluble mold release agent and a production how that can be sufficiently suppressed seizure.

  In the present invention, the “aluminum die casting mold member” refers to a member that comes into contact with the molten aluminum among the mold used for the aluminum die casting and the parts set in the mold cavity. Accordingly, not only the mold in which the cavity is formed, but also the die casting pin, the core, the insert and the like set in the cavity are also included in the “aluminum die casting mold member” of the present invention. Moreover, the surface of the aluminum die casting mold member that has been subjected to the surface treatment (nitriding, ceramic coating, DLC (diamond like carbon), etc.) usually used for die casting molds is also included in the aluminum die casting mold member. .

It is a schematic sectional drawing of the mold release agent tank as an example of the manufacturing apparatus of the water-soluble mold release agent which concerns on this embodiment. It is a schematic sectional drawing of the mold release agent tank as another example of the manufacturing apparatus of the water-soluble mold release agent which concerns on this embodiment.

(Composition of release agent)
The water-soluble release agent according to the present invention contains water as a solvent, a silicon compound such as modified silicone dissolved in water, and a second metal compound dissolved in water. The second metal compound is an oxide, hydroxide, or carbonate of a second metal that is at least one or more selected from the group consisting of Mg, Ca, Ba, and Al.

  The water-soluble mold release agent having such a configuration is applied to an aluminum die casting mold member such as a die surface of a cavity of an aluminum die casting mold or a die casting pin set in the cavity. Thereafter, when the molten aluminum is injected into the cavity, the molten aluminum comes into contact with the water-soluble release agent. At this time, a compound layer of the silicon compound and the second metal compound is formed as a glass layer by reacting the silicon compound and the second metal compound contained in the water-soluble release agent by receiving heat from the molten aluminum. Here, when the second metal compound is not contained in the water-soluble mold release agent, the silicon compound in the water-soluble mold release agent reacts with the molten aluminum, so that aluminum seizure occurs. By dissolving the second metal compound in the water-soluble mold release agent, when it comes into contact with the molten aluminum, the heat of the silicon compound and the second metal compound easily proceeds, and the glass layer is successfully formed. It is estimated that.

  This glass layer may be very thinly coated on the surface of the aluminum die casting mold member. When the glass layer is coated on the surface of the mold member, direct contact between the surface of the mold member and the molten aluminum is hindered by the glass layer, so that the metal component such as SKD61 constituting the mold member and the molten aluminum It is possible to prevent the seizure from occurring due to the reaction. Furthermore, the second metal compound contained in the component constituting the glass layer or the composite compound of silicon and the second metal has poor reactivity with the molten aluminum. Therefore, the occurrence of image sticking on the glass layer can be effectively prevented. The reason why the second metal compound or the composite compound (glass layer) suppresses the reaction with the molten aluminum is that the free energy of oxide formation of the second metal (Mg, Ca, Ba, Al) listed above and the composite with silicon Since the free energy for forming oxide is smaller than the free energy for forming oxide of silicon, it is estimated that it is difficult to react with aluminum as compared with the silicon compound alone.

  Such a glass layer is formed on the surface of the mold member when the surface treatment layer (CrN layer, TiN layer, TiAl layer, DLC layer, etc.) is formed on the surface of the mold member. It has the effect of suppressing layer damage. Furthermore, since this glass layer exhibits a heat insulating effect, it has an effect of suppressing damages such as thermal shock applied to the mold and mold cracking due to a thermal cycle.

  In the water-soluble release agent according to the present invention, in addition to the above-described components (water, silicon compound, second metal compound), components usually contained in the release agent may be contained. For example, a synthetic ester or a surfactant may be contained.

  The silicon compound in the water-soluble release agent according to the present invention is dispersed in water in such a manner that it has releasability, and is generally used as a water-soluble release agent in the water-soluble release agent according to the present invention. It may be present in the agent, and for example, it may be contained in the water-soluble release agent as a polymer having a main skeleton with a siloxane bond such as modified silicone.

The second metal compound in the water-soluble release agent according to the present invention is at least one (second metal) oxide, hydroxide or carbonate selected from the group consisting of Mg, Ca, Ba, and Al. , Dissolved in a solvent (water). Those that do not dissolve in water cannot be used as the second metal compound of the present invention. The second metal compound may be composed of only one kind of metal compound (for example, MgO), or may be composed of a plurality of metal compounds (for example, MgO and CaCO ₃ ).

  If the pH of the water-soluble release agent according to the present invention is 8 or more, the antiseptic effect of the water-soluble release agent is high, so that the quality of the water-soluble release agent can be stabilized for a long period of time. If the pH of the water-soluble release agent is less than 8, it is not preferable because deterioration due to corrosion occurs. On the other hand, if the pH of the water-soluble release agent is higher than 11, it is not preferable from the environmental viewpoint. Therefore, the pH of the water-soluble release agent is 8 to 11, more preferably 9 to 10.

When the second metal compound (oxide, hydroxide, carbonate) is dissolved in water, the second metal is ionized and OH ⁻ ions are generated, so that the water-soluble release agent exhibits alkalinity. If the dissolved amount of the second metal compound is too small, the pH does not reach 8, and if too much, the pH exceeds 11. Therefore, in order to keep the pH of the water-soluble release agent in the range of 8 to 11, a metal compound that is appropriately dissolved in water may be selected as the second metal compound. MgO, Mg (OH) ₂ , CaCO ₃ , BaCO ₃ , and Al (OH) ₃ are preferably used as the second metal compound that satisfies such conditions. CaO is not good because the amount of dissolution is too large, and the pH of the release agent easily exceeds 11 and shows a strong alkali of about 14.

In particular, if the second metal compound is MgO (magnesium oxide) or CaCO ₃ (calcium carbonate), it may be inexpensive and easy to handle. The amount of MgO or CaCO ₃ dissolved in water is not so large, and the pH falls within the range of 8 to 11 even when dissolved until saturation. Therefore, the pH of the release agent can be adjusted in the range of 8 to 11 by dissolving solid MgO or CaCO ₃ in the silicon compound-dispersed aqueous solution until it is saturated. For this reason, it is easy to manage pH. In this case, the dissolution amount of MgO or CaCO ₃ in the release agent is preferably 0.003 g / l or more and 0.7 g / l or less. If it is the density | concentration within the said range, pH of a water-soluble mold release agent can be settled in the range of 8-11.

(Manufacturing method of release agent)
The water-soluble release agent according to the present invention comprises Mg, Ca, Ba, and Al in the first step of supplying a silicon compound dispersion aqueous solution into the release agent tank and the silicon compound dispersion aqueous solution in the release agent tank. And a second step of dissolving a second metal compound that is at least one oxide, hydroxide or carbonate selected from the group.

  In the first step, a silicon compound dispersed aqueous solution is supplied into the release agent tank. The release agent tank may be any container as long as it can store the silicon compound-dispersed aqueous solution. Moreover, as the silicon compound dispersion aqueous solution supplied to the release agent tank, for example, a water-soluble release agent mainly composed of modified silicone is preferably used. The silicon compound-dispersed aqueous solution supplied into the release agent tank in the first step has a basic function (release property, etc.) as a water-soluble release agent.

  In the second step, the second metal compound is dissolved in the silicon compound-dispersed aqueous solution in the release agent tank. In this case, the second metal compound may be dissolved in the silicon compound dispersion aqueous solution by mixing the powder of the second metal compound in the silicon compound dispersion aqueous solution, or the second metal compound may be dissolved in the silicon compound dispersion aqueous solution. The second metal compound may be eluted in the silicon compound-dispersed aqueous solution by immersing the solid material.

In addition, when the second metal compound (oxide, hydroxide, carbonate) is dissolved in the silicon compound-dispersed aqueous solution in the second step, the second metal is ionized as described above, and OH ⁻ ions are generated, resulting in water-solubility. The mold release agent is alkaline. In this case, the amount of the second metal compound dissolved in the silicon compound-dispersed aqueous solution may be adjusted so that the pH of the water-soluble release agent in the release agent tank is 8 to 11. Further, in this case, the second metal compound is MgO or CaCO ₃ , and in the second step, MgO or CaCO ₃ is added to the silicon compound dispersed aqueous solution until the amount of MgO or CaCO ₃ dissolved in the silicon compound dispersed aqueous solution is saturated. It is good to dissolve. Even when MgO or CaCO ₃ dissolves in a small amount in the silicon compound-dispersed aqueous solution and dissolves until it is saturated, the pH of the water-soluble release agent is 8 or more and 11 or less. Therefore, for example, by immersing a solid material of MgO or CaCO _{3 in} an aqueous silicon compound dispersion and allowing it to stand for a while, the pH of the release agent falls within the range of 8 to 11 without special management. Can do. In addition, by always bringing the solid material of MgO or CaCO ₃ into contact with the release agent in this way, for example, even when a silicon compound dispersed aqueous solution is replenished, MgO or CaCO ₃ is immediately dispersed in the silicon compound. It can be dissolved in an aqueous solution. Therefore, the dissolved amount and pH of MgO and CaCO ₃ can be maintained almost constant.

(Mold release agent production equipment)
The apparatus for producing a water-soluble release agent according to the present invention includes a first chamber and a second chamber. A silicon compound-dispersed aqueous solution is supplied to the first chamber. The second chamber contains MgO or CaCO ₃ solids. The second chamber communicates with the first chamber, and the silicon compound dispersed aqueous solution in the first chamber can enter the second chamber. When the silicon compound-dispersed aqueous solution in the first chamber enters the second chamber, the solid matter of MgO or CaCO ₃ is always immersed in the silicon compound-dispersed aqueous solution. Therefore, MgO or CaCO ₃ dissolves in the silicon compound dispersed aqueous solution. The dissolved MgO or CaCO ₃ is released into the first chamber. Thus, the water-soluble mold release agent in which MgO or CaCO ₃ is dissolved is produced in the production apparatus.

  FIG. 1 is a schematic cross-sectional view of a release agent tank as an example of an apparatus for producing a water-soluble release agent according to this embodiment. As shown in FIG. 1, the release agent tank 1 includes a rectangular parallelepiped first casing 2 and a second casing 3 disposed inside the first casing 2. The second casing 3 is disposed in the first casing 2 in a suspended state.

A silicon compound-dispersed aqueous solution (for example, a commercially available modified silicone-containing water-soluble release agent) L is supplied into the first casing 2 of the release agent tank 1. Further, in the second casing 3, for example, MgO solid material such as MgO clinker or CaCO ₃ solid material (hereinafter referred to as solid material S) is accommodated. The size of the solid S is such that it can be easily dissolved in the silicon compound-dispersed aqueous solution, specifically, the diameter (representative diameter) is 1 to 50 mm, preferably 3 to 30 mm.

The second casing 3 is made of, for example, a wire mesh. Therefore, the space in the second casing 3 is a space outside the second casing 3 and communicates with the space in the first casing 2. Accordingly, the silicon compound dispersed aqueous solution supplied into the first casing 2 also enters the space in the second casing 3. As a result, the solid S of MgO or CaCO ₃ accommodated in the second casing 3 is always immersed in the silicon compound-dispersed aqueous solution in the second casing 3. The space inside the first casing 2 and outside the second casing 3 corresponds to the first chamber of the present invention, and the space inside the second casing 3 corresponds to the second chamber of the present invention.

  A stirring device 4 is attached to the inner wall portion of the first casing 2. The silicon compound dispersed aqueous solution in the first casing 2 is stirred by the operation of the stirring device 4. A pressure sensor 5 and a liquid level sensor 6 are attached to the first casing 2. The pressure sensor 5 detects the pressure in the first casing 2. The liquid level sensor 6 detects the height of the liquid level of the silicon compound dispersed aqueous solution supplied into the second casing 2. The pressure information detected by the pressure sensor 5 and the liquid level information detected by the liquid level sensor 6 are input to a control device (not shown).

  Further, a supply unit 7 and a discharge unit 8 are attached to the release agent tank 1. The supply unit 7 is a device for supplying the silicon compound dispersed aqueous solution into the release agent tank 1, and the discharge unit 8 supplies the water-soluble release agent in the release agent tank 1 to the outside (for example, a mold cavity). It is an apparatus for discharging. The supply unit 7 includes a supply pipe 71 and a supply pump 72. One end of the supply pipe 71 is connected to a supply source of a silicon compound dispersed aqueous solution (not shown), and the other end opens into a space in the first casing 2. The supply pump 72 is interposed in the middle of the supply pipe 71. The discharge unit 8 includes a discharge pipe 81 and a discharge pump 82. One end of the discharge pipe 81 opens into the first casing 2, and the other end is connected to a supply destination of the water-soluble release agent. The discharge pump 82 is interposed in the middle of the discharge pipe 81.

  When the liquid level detected by the liquid level sensor 6 is equal to or lower than a predetermined height (for example, the height at which the second casing 3 is disposed), a drive command signal is sent from the control device (not shown) to the supply pump 72. Is output. Thereby, the supply pump 72 is driven, and the silicon compound dispersed aqueous solution flows through the supply pipe 71 and is supplied into the first casing 2. In addition, when a drive command signal is output to the discharge pump 82 from a control device (not shown), the discharge pump 82 is driven, and the water-soluble release agent in the first casing 2 flows through the discharge pipe 82 and is supplied to the outside. It is discharged first. The discharge amount of the water-soluble release agent is controlled based on the pressure detected by the pressure sensor 5.

According to the release agent tank 1 having such a configuration, the solid matter S of MgO or CaCO ₃ is always in contact with the silicon compound-dispersed aqueous solution in the second casing 3, so that the solid matter S is in the second casing 2. It elutes in the silicon compound dispersion aqueous solution. The eluted MgO or CaCO ₃ is released from the second casing 3 and diffuses in the first chamber 2. Since the first chamber 2 is agitated by the agitator 4, the MgO or CaCO ₃ released into the first chamber 2 is evenly dispersed. For this reason, the dissolution amount of MgO or CaCO ₃ contained in the water-soluble release agent discharged by the discharge unit 8 can be made uniform.

It allows the amount of dissolved solids S which dissolves in the silicon compound dispersed in an aqueous solution is saturated to be immersed always solids S of MgO or CaCO ₃ in the second casing within 3 to the silicon compound dispersion solution. The pH of the water-soluble release agent at the time of saturation falls within the range of 8-11. Therefore, even without special pH control, the solid material S is simply placed in the second casing 3 and left for a predetermined time (the time required for saturation of the solid material S) or longer, so that the release agent tank 1 The pH of the water-soluble release agent can be adjusted to 8-11.

  Further, even when the silicon compound dispersion aqueous solution is newly replenished from the supply unit 7 and the pH of the aqueous solution in the release agent tank 1 temporarily decreases, the dissolution of the solid matter S rapidly proceeds and the pH is automatically adjusted. The original weak alkaline value can be restored. For this reason, the pH of the water-soluble release agent can be kept almost constant.

(First embodiment)
An MgO clinker having a size of about 5 mm to 30 mm is placed in the second casing 3 of the release agent tank 1 shown in FIG. 1, and then a commercially available water-soluble release agent (manufactured by Yushiro Chemical) is placed in the first casing 2. Was supplied (first step). Here, the supplied commercial water-soluble release agent is a silicon compound-dispersed aqueous solution in which a modified silicone (silicon compound) is dispersed in water. The water-soluble mold release agent supplied into the first casing 2 enters the second casing 3, whereby the MgO clinker in the second casing 3 is immersed in the water-soluble mold release agent (second step). . In this state, the solution was left for a whole day and night to saturate the dissolved amount of MgO dissolved in the water-soluble release agent. Thus, a water-soluble release agent (MgO-containing water-soluble release agent) in which the silicon compound and MgO were dissolved was produced.

  A die casting pin made of hot die steel (SKD61) was set in the cavity of the test die casting mold, and an MgO-containing water-soluble release agent was applied to the surface of the set die casting pin. Thereafter, molten aluminum was injected into the cavity using a 500-ton die casting machine. The application of the MgO-containing water-soluble release agent to the die casting pin and the injection of molten aluminum were repeated, and the number of molten aluminum shots and the state of aluminum metal seizing (adhesion state) on the die casting pin were investigated.

(Second embodiment)
A lump of CaCO _{3 having} a size of about 5 mm to 30 mm is put in the second casing 3 of the release agent tank 1 shown in FIG. 1, and then the commercially available water-soluble water used in the first embodiment is put in the first casing 2. Sexual release agent (manufactured by Yushiro Chemical) was supplied (first step). The water-soluble mold release agent supplied into the first casing 2 enters the second casing 3, whereby the CaCO ₃ lump in the second casing 3 is immersed in the water-soluble mold release agent (second Process). In this state, the solution was left for a whole day and night to saturate the dissolved amount of CaCO ₃ dissolved in the water-soluble release agent. Thus, a water-soluble release agent (CaCO ₃ -containing water-soluble release agent) in which the silicon compound and CaCO ₃ were dissolved was produced.

A die casting pin made of hot die steel (SKD61) was set in the cavity of the test die casting mold, and a CaCO ₃ -containing water-soluble release agent was applied to the surface of the set die casting pin. Thereafter, molten aluminum was injected into the cavity using a 500-ton die casting machine. The application of the water-soluble release agent containing CaCO ₃ to the die casting pin and the injection of the molten aluminum were repeated, and the number of shots of the molten aluminum and the state of the aluminum metal sticking to the die casting pin (adhesion state) were investigated.

(Third embodiment)
An MgO-containing water-soluble release agent was produced in the same manner as in the first example. Further, a TiAlN-coated die-cast pin was produced by coating a TiAlN film on the surface of a die-cast pin made of hot die steel (SKD61) by the PVD method. And the TiAlN coating die-cast pin was set in the cavity of the die-casting die for a test, and the MgO containing water-soluble mold release agent was apply | coated to the set TiAlN coating die-cast pin. Thereafter, molten aluminum was injected into the cavity using a 500-ton die casting machine. The application of the MgO-containing water-soluble release agent to the TiAlN-coated die casting pin and the injection of the molten aluminum were repeated, and the number of shots of the molten aluminum and the seizure status (adhesion status) of the aluminum metal on the TiAlN-coated die casting pin were investigated.

(Comparative Example 1)
A die casting pin made of hot die steel (SKD61) was set in the cavity of the test die casting mold, and a commercially available water-soluble release agent was applied to the set die casting pin. Thereafter, molten aluminum was injected into the cavity using a 500-ton die casting machine. The application of a commercially available water-soluble release agent to the die casting pin and injection of molten aluminum were repeated, and the number of molten aluminum shots and the state of aluminum metal sticking (adhesion) to the die casting pin were investigated.

(Comparative Example 2)
A TiAlN-coated die-cast pin was produced by coating a TiAlN film on the surface of a die-cast pin made of hot die steel (SKD61) by the PVD method. And the TiAlN coating die-cast pin was set in the cavity of the die-casting die for a test, and the commercially available water-soluble mold release agent was apply | coated to the set TiAlN coating die-cast pin. Thereafter, molten aluminum was injected into the cavity using a 500-ton die casting machine. The application of a commercially available water-soluble release agent to the TiAlN coated die casting pin and the injection of molten aluminum were repeated, and the number of shots of the molten aluminum and the seizure status (adhesion status) of the aluminum metal on the TiAlN coated die casting pin were investigated.

  In the above Examples and Comparative Examples, the same commercially available water-soluble release agent was used. In addition to silicon compounds such as organically modified silicone, this commercially available water-soluble release agent contains synthetic esters, nonionic surfactants, and the like.

(Confirmation test of burn-in situation)
Table 1 shows the results of investigation of the burn-in situation in each example and each comparative example.

As can be seen from Table 1, in the case shown in Comparative Example 1 in which molten aluminum was repeatedly injected into a cavity in which a die-cast pin coated with a commercially available water-soluble release agent was set, injection of molten aluminum was repeated 45 shots. At that time, Al having a thickness exceeding the allowable dimension (60 μm) of the product adhered to the die cast pin. On the other hand, in the cases shown in Examples 1 and 2 in which molten aluminum was repeatedly injected into a cavity in which a die casting pin on which a MgO-containing water-soluble release agent or a CaCO ₃ -containing water-soluble release agent was applied was set, When the injection was repeated 120 shots, Al having a thickness of an allowable dimension (60 μm) finally adhered. In addition, in the case shown in Comparative Example 2 in which molten aluminum was repeatedly injected into a cavity in which a TiAlN coated die casting pin coated with a commercially available water-soluble release agent was set, when the shot of molten aluminum was repeated 45 shots, 25 μm In the case where the molten aluminum was repeatedly injected into the cavity in which the TiAlN coating die-casting pin coated with the MgO-containing water-soluble release agent was set, the Al of the above thickness was adhered. Even when the injection was repeated 120 shots, only 15 μm thick Al adhered. From these facts, when the water-soluble mold release agent of this example, that is, the MgO-containing water-soluble mold release agent or the CaCO ₃ -containing water-soluble mold release agent is used, the aluminum die-casting mold member is effectively seized. It can be seen that it can be prevented. The reason for this is that, as described above, the MgO-containing water-soluble mold release agent or CaCO ₃ -containing water-soluble mold release agent applied to the surface of the die-cast pin reacts with the heat of the molten aluminum to form a silicon compound and a second metal compound. It is considered that this is because a glass layer composed of a compound layer is produced, and the produced glass layer is thinly coated on the surface of the die cast pin, and the coated glass layer blocks reaction with molten aluminum and inhibits seizure.

In the above embodiment, MgO and CaCO ₃ are used as the second metal compound, but any compound may be used as long as it is an oxide, hydroxide, or carbonate of Mg, Ca, Ba, or Al. good. However, CaO (calcium oxide) is not preferred because it is strongly alkaline when dissolved in a water-soluble release agent. Further, the release agent tank 1 shown in FIG. 1 described in the above embodiment is arranged in a state where the second casing 3 in which the solid S of the second metal compound is accommodated is suspended in the first casing 2. However, as shown in FIG. 2, the two casings 3 containing the solids S of the second metal compound may be simply placed on the first casing 2. Alternatively, the first casing 2 and the second casing 3 that are in communication with each other are separated, and each chamber surrounded by both casings is filled with a silicon compound-dispersed aqueous solution, and either chamber is filled with the second metal compound. You may comprise so that the solid substance of this may be accommodated. The present invention can be modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Release agent tank (manufacturing apparatus), 2 ... 1st casing, 3 ... 2nd casing, 4 ... Stirrer, 5 ... Pressure sensor, 6 ... Liquid level sensor, 7 ... Supply unit, 8 ... Discharge unit

Claims (2)

A water-soluble mold release agent used for aluminum die casting mold members,
Water as a solvent, a silicon compound dispersed in water as a solvent, and at least one oxide, hydroxide or carbonate selected from the group consisting of Mg, Ca, Ba, and Al. a second metal compound dissolved in water, only including,
A water-soluble mold release agent , wherein the second metal compound is MgO or CaCO ₃ , and MgO or CaCO ₃ is dissolved in a saturated state . A method for producing a water-soluble mold release agent used for an aluminum die casting mold member,
A first step of supplying a silicon compound-dispersed aqueous solution into the release agent tank;
A second metal compound that is at least one oxide, hydroxide or carbonate selected from the group consisting of Mg, Ca, Ba, and Al is dissolved in the silicon compound-dispersed aqueous solution in the release agent tank. Process,
Only including,
The second metal compound is MgO or CaCO ₃ ;
In the second step, the solid matter of MgO or CaCO ₃ is immersed in the silicon compound-dispersed aqueous solution in the release agent tank and left for a predetermined time or longer until the dissolved amount of MgO or CaCO ₃ is saturated. A method for producing a water-soluble release agent, which is a step of dissolving MgO or CaCO ₃ .

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