JP5507420B2 - Aqueous release agent composition - Google Patents

Description

  The present invention relates to an aqueous release agent composition, and more particularly to an aqueous release agent composition that is excellent in release properties and can suppress seizure.

Die casting is a casting method in which a molten alloy such as aluminum, magnesium, or zinc is pressed into a die casting mold at a high temperature to produce a casting.
In die casting, generally, a mold release agent is applied to the inner surface of the die casting mold in order to easily remove the casting from the die casting mold.

By the way, as such a release agent, an oil-based release agent and an aqueous release agent are known.
Oil-based mold release agents are excellent in mold release properties, but are flammable and generate bad odors, which is problematic in terms of work environment.
In recent years, an aqueous release agent has attracted attention from the viewpoint of such a working environment. The aqueous release agent generally has a structure in which oil, lubricant, and water are emulsified with a surfactant.

  For example, as an aqueous mold release agent, an aqueous mold release agent obtained by emulsifying natural oil and synthetic oil with a surfactant (for example, see Patent Document 1), an aqueous mold release using a silicone oil having excellent lubricity among oils. An agent (for example, see Patent Documents 2 to 5), an aqueous release agent (for example, Patent Documents 6 and 7) containing a metal oxide such as aluminum oxide as a lubricant, silicone oil, a solid lubricant, an organic binder, An aqueous release agent containing a dispersant and water (for example, see Patent Document 8) is known.

JP-A-7-62380 JP-A-11-277211 JP 2001-259787 A JP 2004-91566 A JP 2005-54090 A JP 2001-71092 A JP 2005-254256 A JP 2002-282997 A

  However, any of the aqueous release agents described in Patent Documents 1 to 8 has insufficient release properties. For this reason, the casting surface of a casting does not become smooth. Further, there is a problem in that seizure of the aqueous release agent occurs on the contact surface between the die casting mold and the casting.

  This invention is made | formed in view of the said situation, and it aims at providing the aqueous | water-based mold release agent composition which is excellent in mold release property and can suppress seizing.

  The inventors of the present invention have intensively studied to solve the above problems, and surprisingly, the above problems can be solved by including silica that becomes colloidal silica when dispersed in a colloidal liquid composed of an alkali compound and water. The present invention has been found and the present invention has been completed.

The present invention is (1) an aqueous release agent composition used for die casting, which comprises colloidal silica composed of silica, an alkali compound and water , silicone oil for improving lubricity, and mineral oil. Containing a lubricating oil, a nonionic surfactant for emulsifying the lubricating oil and the silicone oil, a lubricating agent made of an organic molybdenum compound, and a lubricating auxiliary agent made of an organic zinc compound, and having a silica particle size of 10 to 20 nm It exists in an aqueous release agent composition.

  The present invention resides in (2) the aqueous mold release agent composition according to the above (1), wherein at least a part of the surface of silica is coated with aluminum.

This invention exists in the aqueous | water-based mold release agent composition as described in said ( 1 ) or ( 2 ) whose HLB of ( 3 ) nonionic surfactant is 7-14.

The present invention, (4) a nonionic surfactant is a polyethylene alkyl ether, the carbon number of the alkyl group of the polyethylene alkyl ether Ru der 12-22 above (1) according to any one of - (3) Present in an aqueous release agent composition.

The present invention is as described in any one of (1) to (4) above, wherein the ( 5 ) organic molybdenum compound is at least one selected from the group consisting of molybdenum dithiocarbamate, molybdenum dithiophosphate, and molybdenum-amine complex. Present in an aqueous release agent composition.

In the present invention, ( 6 ) the organomolybdenum compound contains a molybdenum atom and a sulfur atom, the content of molybdenum atom per one molecular weight of the organomolybdenum compound is 4.5% by mass or less, and the content of sulfur atom is 5% by mass. % Of the aqueous release agent composition according to any one of the above (1) to (5) .

The aqueous mold release according to any one of the above ( 1 ) to ( 6 ), further comprising ( 7 ) a cationic surfactant that is a tetraalkylammonium salt or an anionic surfactant that is an alkyl sulfate. Present in the agent composition.

This invention exists in the aqueous | water-based mold release agent composition as described in any one of said (1)-(7) whose lubrication adjuvant is zinc dialkyl dithiophosphate ( 8 ).

In the aqueous release agent composition of the present invention, the releasability is greatly improved by incorporating silica having a particle diameter of 10 to 20 nm as colloidal silica. In particular, since silica is excellent in heat resistance, it is effective when the die casting mold is at a high temperature. At this time, the casting surface of the casting also becomes smooth. In the present invention, “releasability” means the degree of ease of separation of a casting from the die-casting mold, and “casting surface” means the surface of the casting.
Further, by containing colloidal silica, seizure of the aqueous release agent composition on the casting can be prevented and coloring of the casting can be suppressed even if the die casting mold is at a high temperature.

  In the aqueous mold release agent composition of the present invention, by further containing a lubricating oil and / or silicone oil for improving the lubricity, the lubricity of the die casting mold can be improved, and addition of silica is also possible. The amount can be reduced. Thereby, it can suppress that a die-cast metal mold | die becomes white with the silica added excessively.

  At this time, it is preferable to contain a nonionic surfactant. In this case, the lubricating oil and / or silicone oil can be reliably emulsified. In addition, emulsification stability improves more as HLB of nonionic surfactant is 7-14.

  In the aqueous release agent composition of the present invention, when a lubricant composed of an organic molybdenum compound is further contained, the lubricity to the die casting mold is further improved, and in addition, a lubricating auxiliary agent composed of an organic zinc compound is added. Furthermore, when it contains, the lubricity based on a lubricant improves further. Thereby, the mold release property of a casting and a die-casting die is further improved.

  Here, in the said aqueous mold release agent composition, when content of the molybdenum atom of an organic molybdenum compound is 4.5 mass% or less, and content of a sulfur atom is 5 mass% or less, it depends on molybdenum disulfide. The generation of coloring can be reduced as much as possible, and the generation of malodor can also be suppressed.

(A)-(c) of FIG. 1 is a figure for demonstrating the outline | summary of the mold release test in an Example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary.

  The aqueous release agent composition according to this embodiment includes colloidal silica, a silicone oil for improving lubricity, a lubricating oil composed of a mineral oil, and a nonionic surfactant that emulsifies the lubricating oil and the silicone oil. And a lubricant made of an organic molybdenum compound, a lubricating auxiliary agent made of an organic zinc compound, and water.

Since the aqueous release agent composition contains colloidal silica, the release property of the casting is greatly improved.
Moreover, since the silicone oil and lubricating oil which improve lubricity are contained, even when the addition amount of the silica contained in colloidal silica is reduced, the mold release property is sufficiently excellent. That is, when the die casting mold is at a low temperature, the silicone oil and the lubricating oil further improve the releasability of the casting. Silica improves the releasability of the casting regardless of the temperature of the die casting mold.
Furthermore, since the aqueous release agent composition contains a lubricant and a lubricating auxiliary agent, the release property of the casting is further improved.

Hereinafter, each component will be described in more detail.
(Colloidal silica)
First, in the present invention, the colloidal silica contained in the aqueous release agent composition is colorless and transparent, and comprises silica, an alkali compound, and water. That is, it consists of silica and a colloidal liquid composed of an alkali compound and water. The silica used in the present invention is in the form of a white powder and becomes colloidal when dispersed in a colloidal solution.

Here, silica improves the releasability of the casting. In particular, it is effective when die casting is performed in a state where the temperature of the die casting mold is 350 ° C. or higher. At this time, the casting surface of the casting after mold release becomes extremely smooth.
Further, by dispersing silica in a colloidal liquid to form colloidal silica, it is possible to prevent precipitation or the like from occurring over time.
Furthermore, since silica is excellent in heat resistance, seizure of the aqueous release agent composition on the casting can be prevented and coloring of the casting can be suppressed even when the die casting mold is at a high temperature.

  Silica used in the aqueous release agent composition has a particle size of 10 to 20 nm. If the particle size is less than 10 nm, the particles are likely to aggregate, and if the particle size exceeds 20 nm, the surface of the casting may be rough.

  For example, the silica is preferably one in which at least a part of the surface is coated with aluminum. In this case, even when the pH of the medium water is slightly changed, the colloidal state can be stably maintained. In addition, it is preferable that the pH of the silica at this time is 8.0-9.0.

  Silica preferably has a specific gravity at 20 ° C. of 1.1 to 1.2. When the specific gravity is less than 1.1, there is a drawback that it takes time to make a colloidal state compared to the case where the specific gravity is in the above range. In some cases, the colloidal state may not be maintained as compared with the case of the above.

A colloidal solution is obtained by dissolving an alkali compound in water.
Here, examples of the alkali compound include sodium hydroxide and potassium hydroxide. In addition, content of the alkaline compound in a colloid liquid is adjusted according to pH mentioned later. For example, it may be about 0.2% by mass.

  And it is preferable that the colloidal silica obtained is adjusted to pH 5-11. Thereby, silica becomes stable colloidal form without being precipitated with time.

(Silicone oil)
The silicone oil contained in the aqueous release agent composition improves the lubricity of the die casting mold. In particular, when die casting is performed in a state where the temperature of the die casting mold is lower than 350 ° C., the releasability can be further improved.
By this, since the addition amount of a silica can be reduced, it can suppress that a die-casting die becomes white based on provision of a large amount of silica.

  Examples of such silicone oils include straight silicone oils such as dimethyl silicone oil, methylphenyl silicone oil and methylhydrogen silicone oil, and modified silicone oils such as amino-modified silicone oil. These may be used alone or in combination.

(Lubricant)
The lubricating oil contained in the aqueous release agent composition is composed of mineral oil. Such a mineral oil improves the lubricity of the die-casting die, like the silicone oil. In particular, when die casting is performed in a state where the temperature of the die casting mold is lower than 350 ° C., the releasability can be further improved.
By this, since the addition amount of a silica can be reduced, it can suppress that a die-casting die becomes white based on provision of a large amount of silica.

  Such mineral oil is not particularly limited as long as it is obtained by fractional distillation from oil of mineral substances such as petroleum. For example, so-called engine oil, machine oil, turbine oil, cylinder oil, piston oil, spindle oil, gear oil and the like can be mentioned. These may be used alone or in combination.

  The lubricating oil is preferably a mixture of a high flash point oil composed of a high flash point mineral oil and a low flash point oil composed of a low flash point mineral oil. The high flash point oil preferably has a flash point of 300 to 400 ° C, more preferably 320 to 350 ° C. The low flash point oil preferably has a flash point of 200 to 300 ° C, more preferably 250 to 300 ° C. In these cases, the releasability in die casting at 200 to 400 ° C. is further improved.

The lubricating oil (mineral oil) preferably contains a synthetic oil. In this case, the emulsification of the mineral oil proceeds smoothly.
Examples of such synthetic oil include fatty acid esters such as maleic acid esters.

(Nonionic surfactant)
The nonionic surfactant contained in the aqueous release agent composition exhibits a function of emulsifying the above-described silicone oil and lubricating oil. In addition, when a lubricant and a lubricating auxiliary agent are included, the function of dispersing the lubricant and the lubricating auxiliary agent is also exhibited.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene alkylphenyl ethers, and the like. These may be used alone or in combination.
Among these, the nonionic surfactant is preferably a polyethylene alkyl ether from the viewpoint of emulsifiability, and among the polyethylene alkyl ethers, the carbon number of the alkyl group is more preferably 12 to 22, and the carbon number More preferred is 18 polyoxyethylene oleyl ether.

The HLB of the nonionic surfactant is 7 to 14, and preferably 10 to 14.
If the HLB is less than 7 or exceeds 14, the above-described lubricant and silicone oil may not be emulsified, or the dispersibility of the lubricant and the lubricating auxiliary agent may become unstable. In addition, when mixing a some nonionic surfactant, it adjusts so that HLB of the whole mixed nonionic surfactant may become in the said range.

The surface tension of the nonionic surfactant based on the Traube method is preferably 40 mN / m or more when a 0.1% solution is used.
Moreover, it is preferable that the interfacial tension based on the Traube method of a nonionic surfactant is 15 mN / m or more (25 degreeC) with respect to a kerosene 0.1% solution. If the surface tension or the interfacial tension is too low, dripping may occur from the spray nozzle when spraying with a spray device.

  If necessary, the nonionic surfactant may be used in combination with a cationic surfactant such as a tetraalkylammonium salt or an anionic surfactant such as an alkyl sulfate.

(lubricant)
The lubricant contained in the aqueous release agent composition is composed of an organic molybdenum compound.
A lubricant composed of an organomolybdenum compound exhibits a function of improving lubricity regardless of temperature. That is, the lubricating oil described above or the silicone oil described later is easily affected by the temperature, but the lubricant made of the organic molybdenum compound is not easily affected by the temperature as in the case of silica.

  The organic molybdenum compound is preferably at least one selected from the group consisting of molybdenum dithiocarbamate, molybdenum dithiophosphate, and a molybdenum-amine complex (such as a dialkylamine molybdate salt). Among these, the organic molybdenum compound is preferably molybdenum dithiocarbamate from the viewpoints of lubricity and corrosion resistance. Note that these organic molybdenum compounds are different from inorganic molybdenum disulfide. For this reason, it can prevent that precipitation generate | occur | produces with time like molybdenum disulfide.

The organomolybdenum compound contains a molybdenum atom and a sulfur atom, the content of molybdenum atoms per molecular weight of the organomolybdenum compound is 4.5% by mass or less, and the content of sulfur atoms is preferably 5% by mass or less. .
When the content of molybdenum atoms exceeds 4.5% by mass, there is a risk of forming molybdenum disulfide coloring on the surface of the die casting mold as compared with the case where the content is within the above range. When the content exceeds 5% by mass, a bad odor may be generated as compared with the case where the content is in the above range.

(Lubricant aid)
The lubricating auxiliary agent contained in the aqueous release agent composition is composed of an organic zinc compound.
Lubricating adjuvants composed of organozinc compounds improve the lubricity of organomolybdenum compounds. For this reason, the aqueous mold release agent composition containing the lubricant and the lubrication auxiliary agent further improves the lubricity based on the lubricant between the casting and the die casting mold, and the mold release property is extremely improved.

  Examples of the lubricating aid include zinc dialkyldithiophosphate. The zinc dialkyldithiophosphate also exhibits a function of inactivating the oxidizing substance and suppresses oxidation of the lubricating oil and silicone oil.

Next, the blending ratio of each component will be described.
In the aqueous release agent composition, the blending ratio of silica is 0.5 to 20% by mass, and more preferably 1 to 8% by mass. When the blending ratio of the silica is less than 0.5% by mass, the merit of adding silica cannot be sufficiently exhibited as compared with the case where the blending ratio is within the above range. Moreover, when a mixture ratio exceeds 20 mass%, compared with the case where a mixture ratio exists in the said range, an excess silica may adhere to a die-cast metal mold | die.

In the aqueous release agent composition, the blending ratio of the active ingredient of the silicone oil is preferably 5 to 20% by mass. In addition, an active ingredient means the liquid component, when a silicone oil is a liquid, and when a silicone oil is a solid, it means the solid component.
When the blending ratio of the silicone oil is less than 5% by mass, the improvement in lubricity is hardly recognized as compared with the case where the blending ratio is within the above range. Moreover, when a mixture ratio exceeds 20 mass%, the improvement of an effect will not be recognized compared with the case where a mixture ratio exists in the said range.

  In the aqueous release agent composition, the blending ratio of the lubricating oil is 1 to 40% by mass, and preferably 10 to 30% by mass. When the blending ratio of the lubricating oil is less than 1% by mass, the lubricity is insufficient and seizure is likely to occur as compared with the case where the blending ratio is within the above range. Moreover, when a mixing | blending ratio exceeds 40 mass%, coloring of a casting may arise compared with the case where a mixing | blending ratio exists in the said range. Moreover, since it becomes high viscosity, when providing with a spray etc., a nozzle tends to clog.

Moreover, when lubricating oil consists of high flash point oil and low flash point oil, the mixture ratio of high flash point oil is 0-20 mass%, and it is preferable that it is 5-15 mass%. When the blending ratio of the high flash point oil exceeds 20% by mass, the casting surface may be colored as compared with the blending ratio within the above range. In addition, the blending ratio of the high flash point oil means 0 mass% means a state in which the high flash point oil is not included.
On the other hand, the blending ratio of the low flash point oil is 1 to 20% by mass, and preferably 5 to 15% by mass.

In the aqueous release agent composition, the blending ratio of the nonionic surfactant is preferably 3 to 10% by mass.
When the mixing ratio of the nonionic surfactant is less than 3% by mass, emulsification may be insufficient as compared with the case where the mixing ratio is within the above range. Moreover, when a mixture ratio exceeds 10 mass%, compared with the case where a mixture ratio exists in the said range, although emulsification property does not change, it exists in the tendency for a bubble to generate | occur | produce easily.

  In the aqueous release agent composition, the blending ratio of the lubricant is 0.1 to 2% by mass, and more preferably 0.5 to 1.5% by mass. When the blending ratio of the lubricant is less than 0.1% by mass, sufficient releasability cannot be obtained as compared with the case where the blending ratio is in the above range. In addition, when the blending ratio exceeds 2% by mass, the organomolybdenum compound is changed to insoluble molybdenum disulfide in the die casting mold as compared with the case where the blending ratio is in the above range, and the surface of the die casting mold is changed. There is a risk of coloring.

  In the aqueous release agent composition, the blending ratio of the lubricating auxiliary agent is more preferably 0.01 to 0.05% by mass. When the blending ratio of the lubricating auxiliary agent is less than 0.01% by mass, sufficient improvement in the lubricity of the organomolybdenum compound is not observed as compared with the case where the blending ratio is within the above range. On the other hand, when the blending ratio exceeds 0.05% by mass, the lubricity of the organic molybdenum compound is not improved as compared with the case where the blending ratio is within the above range.

In the aqueous release agent composition, the blending ratio of water is preferably 90% by mass or less, and more preferably 50 to 90% by mass from the viewpoint of sprayability.
When the mixing ratio of water exceeds 90% by mass, a so-called Leidenfrost phenomenon is likely to occur as compared with the case where the mixing ratio is in the above range. Moreover, it becomes difficult for the aqueous release agent composition to adhere to the die casting mold.

The aqueous mold release agent composition according to this embodiment may contain an additive.
Examples of such additives include antifungal agents, oil agents, antifreezing agents, antiseptics, film forming agents, extreme pressure agents, antioxidants, antiwear agents, rust inhibitors, viscosity index improvers, pour point depressants, An antifoaming agent etc. are mentioned.

Here, when an antifungal agent is added to the aqueous release agent composition, generation of mold is suppressed, and therefore, long-term storage becomes possible.
Examples of the fungicide include o-phenylphenol, 2,3,4,6-tetrachlorophenol, o-benzyl-p-chlorophenol, methyl p-hydroxybenzoate and the like.
When adding an antifungal agent, it is preferable that the mixture ratio of an antifungal agent is 0.1-1 mass%.

When an oily agent is added to the aqueous release agent composition, adhesion to the die casting mold is further improved.
Oily agents include fatty acids such as coconut oil fatty acid, beef tallow fatty acid, stearic acid, oleic acid, lauric acid, palmitic acid, pintered fatty acid esters such as sorbitan monooleate, glycerin stearic acid ester, glycerin oleic acid ester, etc. Examples include merit acid esters and adipic acid polyesters. These may be used singly or may be mixed and emulsified for use.
When adding an oiliness agent, it is preferable that the mixture ratio of an oiliness agent is 0.5-15 mass%.

When an anti-icing agent is added to the aqueous release agent composition, icing in a cold region can be suppressed.
Examples of the anti-icing agent include ethanol, ethyl diglycol, methyl diglycol, isopropylene glycol and the like.
When the anti-icing agent is added, the blending ratio of the anti-icing agent is preferably 2 to 4% by mass.

When a preservative is added to the aqueous release agent composition, it can be prevented from being spoiled in a hot and humid environment.
Examples of the preservative include alcohol and glycol.
When a preservative is added, the preservative content is preferably about 0.2% by mass.

Examples of the film forming agent include carnauba wax, beeswax, wood wax, montan wax, microwax, paraffin wax and other synthetic resins, polyethylene resin, acrylic resin, urethane resin and other synthetic resins, rapeseed oil, castor oil, soybean oil, palm oil, Fats and oils such as coconut oil, beef tallow and pork tallow are listed. These may be used singly or may be mixed and emulsified for use. Among these, it is preferable to use a polyethylene resin, and it is more preferable that the polymerization degree of the polyethylene resin is about 4000.
Examples of the extreme pressure agent include phosphate esters.

The aqueous mold release agent composition according to the present embodiment is a mixture of mineral oil, lubricant, lubricating aid, silicone oil, and nonionic surfactant, heated and dissolved at 60 to 90 ° C., and stirred. While using hot water, the emulsion was emulsified.
Next, the emulsion is returned to room temperature, and colloidal silica in which silica is dispersed in a colloidal solution (alkali compound + water) is added and stirred to obtain an aqueous release agent composition.

Here, it is preferable that the hot water is obtained by warming tap water, industrial water, pure water or the like to 60 to 90 ° C. In this case, it becomes easy to emulsify.
The emulsification is performed using a known emulsifier such as a homogenizer, a colloid mill, or a planetary mixer.

  The aqueous release agent composition thus obtained preferably has a viscosity at 20 ° C. of 50 mPa · s or less. In this case, it can spray on a die-casting die with an injection device irrespective of manpower.

  The aqueous release agent composition preferably has a pH of 7-9. If the pH is biased toward the acid side or the alkali side, the die casting mold or casting may be corroded. Further, the colloidal state of silica in the aqueous release agent composition may become unstable, and silica may be precipitated.

The aqueous mold release agent composition according to the present embodiment is used by being applied to a die casting mold in die casting. In particular, it is suitably used as a release agent when the temperature of the die casting mold is 200 to 400 ° C.
At this time, a method for applying the aqueous release agent composition is not particularly limited, and examples thereof include a spray method, a shower method, and an ink jet method.

In the application method of the aqueous release agent composition, the raw solution may be applied as it is to the die casting mold. At this time, the amount applied to the die-casting die is a small amount as compared with the conventional case, and if it is 0.3 to 0.5 ml / m ² , sufficient releasability can be exhibited. In addition, the conventional aqueous mold release agent needs to give 20-50 ml / m < ² >.
When the coating amount is less than 0.3 ml / m ² , there may be a case where sufficient releasability may not be obtained as compared with the case where the coating amount is within the above range, and the coating amount is 0.5 ml / m ^2. Even when the coating amount exceeds 1, the improvement in releasability is not observed as compared with the case where the coating amount is within the above range.
Moreover, since the usage-amount of water is not enough, the application | coating method of the said aqueous mold release agent composition has the advantage that generation | occurrence | production of the Leidenfrost phenomenon is suppressed.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, the aqueous release agent composition according to the present embodiment includes a lubricating oil composed of mineral oil in addition to colloidal silica, a nonionic surfactant that emulsifies the lubricating oil, and a silicone oil for improving lubricity. In addition, a lubricant composed of an organomolybdenum compound and a lubricant auxiliary composed of an organozinc compound are included, but it is not always necessary to include these. That is, the aqueous release agent composition of the present invention only needs to contain colloidal silica.

  The aqueous mold release agent composition according to the present embodiment is used as a mold release agent for die casting, and includes cutting oil, rolling oil, piston plunger oil, press working oil, synthetic resin molding release agent, and the like. Can also be used.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

Example 1
10% by mass of low flash point oil (lubricant) having a flash point of 286 ° C., 10% by mass of high flash point oil (lubricant) having a flash point of 320 ° C., and 3% by mass of maleate ester (synthetic oil) And 0.5% by mass of molybdenum dithiophosphate (lubricant), 0.03% by mass of zinc dialkyldithiophosphate (lubricant aid), 5% by mass of silicone oil, polyoxyethylene oleyl ether (nonionic surfactant, HLB12) 5% by mass was mixed, added to 80 ° C. warm water, and emulsified by stirring with a homogenizer to obtain an emulsion.
On the other hand, silica having a particle diameter of 10 to 20 nm (solid content) was added to water containing 0.5% by mass of sodium hydroxide to obtain colloidal silica (solid content of 20% by mass).
Next, the temperature of the emulsified liquid was returned to room temperature, 10% by mass of colloidal silica was added to this while stirring, and further 3% by mass of ethyl diglycol (anti-icing agent) was added to obtain an aqueous release agent composition. . In addition, the mixture ratio of the said warm water is the quantity adjusted so that the whole quantity may be 100 mass%. Further, the molybdenum atom content of the molybdenum dithiophosphate was 4.5% by mass or less, and the sulfur atom content was 5% by mass or less.

(Example 2)
An aqueous release agent composition was obtained in the same manner as in Example 1 except that the high flash point oil was not used.

(Example 3)
An aqueous release agent composition was obtained in the same manner as in Example 1 except that the high flash point oil, the lubricant and the lubricating auxiliary material were not used.

(Example 4)
An aqueous release agent composition was obtained in the same manner as in Example 1 except that the low flash point oil and the high flash point oil were not used.

(Example 5)
The blending ratio of colloidal silica having a solid content of 20% by mass is 2.5% by mass (solid content of 0.5% by mass), the blending ratio of silicone oil is 10% by mass, low flash point oil, high flash point oil, and lubrication. An aqueous release agent composition was obtained in the same manner as in Example 1 except that the agent and the lubricating auxiliary material were not used.

(Example 6)
The blending ratio of colloidal silica having a solid content of 20% by mass is 5% by mass (solid content of 1% by mass), the blending ratio of silicone oil is 10% by mass, low flash point oil, high flash point oil, lubricant and lubrication aid. An aqueous release agent composition was obtained in the same manner as in Example 1 except that no material was used.

(Example 7)
The blending ratio of colloidal silica with a solid content of 20% by mass is 40% by mass (solid content of 8% by mass), the blending ratio of silicone oil is 10% by mass, low flash point oil, high flash point oil, lubricant and lubrication aid. An aqueous release agent composition was obtained in the same manner as in Example 1 except that no material was used.

(Example 8)
The blending ratio of colloidal silica with a solid content of 20% by mass is 45% by mass (solid content of 9% by mass), the blending ratio of silicone oil is 10% by mass, low flash point oil, high flash point oil, lubricant and lubrication aid. An aqueous release agent composition was obtained in the same manner as in Example 1 except that no material was used.

Example 9
Silica having a particle size of 10 to 20 nm (solid content) was added to water containing 0.5% by mass of sodium hydroxide to obtain colloidal silica having a solid content of 50% by mass.
Instead of colloidal silica having a solid content of 20% by mass, colloidal silica having a solid content of 50% by mass was used. And the blending ratio of the colloidal silica having a solid content of 50% by mass is 40% by mass (solid content 20% by mass), except that the low flash point oil, the high flash point oil, the lubricant and the lubricating auxiliary material are not used. In the same manner as in Example 1, an aqueous release agent composition was obtained.

(Example 10)
Silica having a particle size of 10 to 20 nm (solid content) was added to water containing 0.5% by mass of sodium hydroxide to obtain colloidal silica having a solid content of 50% by mass.
Instead of colloidal silica having a solid content of 20% by mass, colloidal silica having a solid content of 50% by mass was used. And the blending ratio of the colloidal silica having a solid content of 50% by mass was 44% by mass (solid content of 22% by mass), except that the low flash point oil, the high flash point oil, the lubricant and the lubricating auxiliary material were not used. In the same manner as in Example 1, an aqueous release agent composition was obtained.

(Example 11)
An aqueous release agent composition was prepared in the same manner as in Example 1 except that the blending ratio of the silicone oil was 4% by mass and the low flash point oil, the high flash point oil, the lubricant and the lubricating auxiliary material were not used. Obtained.

(Example 12)
An aqueous release agent composition was prepared in the same manner as in Example 1 except that the blending ratio of the silicone oil was 20% by mass and the low flash point oil, the high flash point oil, the lubricant, and the lubricating auxiliary material were not used. Obtained.

(Example 13)
An aqueous release agent composition was prepared in the same manner as in Example 1, except that the blending ratio of the silicone oil was 22% by mass, and the low flash point oil, the high flash point oil, the lubricant and the lubricating auxiliary material were not used. Obtained.

(Example 14)
An aqueous release agent composition was obtained in the same manner as in Example 1 except that molybdenum dithiocarbamate was used instead of molybdenum dithiophosphate. In addition, the molybdenum atom content of molybdenum dithiocarbamate was 4.5 mass% or less, and the sulfur atom content was 5 mass% or less.

(Comparative Example 1)
An aqueous release agent composition was obtained in the same manner as in Example 1 except that silica having a particle diameter of 40 to 50 nm was used.

(Comparative Example 2)
An aqueous release agent composition was obtained in the same manner as in Example 1 except that colloidal silica was not used.

(Comparative Example 3)
An aqueous release agent composition was obtained in the same manner as in Example 1 except that silica having a particle size of 8 nm (less than 10 nm) was used.

(Comparative Example 4)
An aqueous release agent composition was obtained in the same manner as in Example 1 except that colloidal silica and silicone oil were not used.

(Comparative Example 5)
An aqueous release agent composition was obtained in the same manner as in Example 1 except that colloidal silica and high flash point oil were not used.

(Evaluation 1)
A releasability test was performed on the aqueous release agent compositions obtained in Examples 1 to 14 and Comparative Examples 1 to 5.
(A)-(c) of FIG. 1 is a figure for demonstrating the outline | summary of a mold release test.
First, an iron plate 1 having a length of 200 mm, a width of 200 mm, and a thickness of 16 mm is prepared, heated to a predetermined temperature, and then sprayed with the aqueous release agent compositions obtained in Examples 1 to 14 and Comparative Examples 1 to 5. The release layer 2 was formed from an aqueous release agent composition.
Thereafter, as shown in FIG. 1A, a ring 3 having a diameter of 9.5 mm and a height of 20 mm was placed on the release layer 2, and 120 g of molten aluminum dissolved by heating was poured into the ring 3. The ring 3 is connected to a motor (not shown) via a wire 4.

  Then, after cooling, the molten aluminum (ADC-12 (JIS)) is made into solidified aluminum 5 as shown in FIG. 1B, and the solidified aluminum 5 is put on the solidified aluminum 5 as shown in FIG. A 9 kg weight 6 was placed and the wire 4 was pulled.

1. Seizure When the aqueous mold release agent composition obtained in Examples 1 to 14 and Comparative Examples 1 to 5 was used, the seizure temperature was 350 ° C. and 400 ° C. when the aqueous mold release agent composition was sprayed. Was evaluated. The evaluation of seizure is “A” when there is no seizure on the contact surface with the release layer 2 of the solidified aluminum 5 after being pulled, “B” when seizure is observed, and seizure is observed. What was obtained was designated “C”.

2. Cast surface In the case where the aqueous release agent composition obtained in Examples 1 to 14 and Comparative Examples 1 to 5 was used with the temperature at the time of spraying the aqueous release agent composition being 350 ° C. and 400 ° C. Was evaluated. The evaluation of the cast surface is “A” when the contact surface (cast surface) with the release layer 2 of the solidified aluminum 5 after being pulled is smooth, “B” when the surface is slightly smooth, and “C” when the surface is rough. It was.

3. Adhesion of silica to the mold The temperature at the time of spraying the aqueous release agent composition was 350 ° C. and 400 ° C., and the aqueous release agent compositions obtained in Examples 1 to 14 and Comparative Examples 1 to 5 were used. In some cases, the silica adhesion to the mold was evaluated. The evaluation of silica adhesion is “A” when silica is not recognized on the contact surface of the solidified aluminum 5 after being pulled with the release layer 2, “B” when silica is slightly recognized, and silica being collected. What was recognized was designated as “C”.

4). Release resistance When the aqueous release agent composition was sprayed at 350 ° C. and 400 ° C. and the aqueous release agent compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 5 were used, the wire 4, the amount of force (kgf / cm ² ) when the solidified aluminum 5 and the weight 6 were pulled was measured. In addition, it means that a mold release property is excellent, so that the value of mold release resistance is small.

  The obtained results and comprehensive evaluation are shown in Table 1. In the table, “-” means that the releasability was extremely poor and measurement was impossible. The overall evaluation is “A” for an aqueous release agent composition that exhibits the most excellent effect, “B” for an aqueous release agent composition that exhibits an excellent effect, and “C” for an aqueous release agent composition that is less effective. "

[Table 1]

From the results of Table 1, the aqueous release agent compositions of Examples 1 to 14 are superior in all aspects of seizure, casting surface and release resistance as compared with those of Comparative Examples 1 to 5. It was.
From the above, according to the aqueous release agent composition of the present invention, it was found that by having the colloidal silica, seizure can be prevented and the release property can be remarkably improved.

  The aqueous mold release agent composition of the present invention is used as a mold release agent for die casting. Specifically, it is used as a release agent that improves the releasability of the casting by giving it to a die casting mold. According to such an aqueous release agent composition, the releasability is improved and seizure can be suppressed.

DESCRIPTION OF SYMBOLS 1 ... Iron plate 2 ... Release layer 3 ... Ring 4 ... Wire 5 ... Solidified aluminum 6 ... Weight

Claims (8)

An aqueous release agent composition used for die casting,
Colloidal silica composed of silica , alkali compound and water ,
Silicone oil to improve lubricity,
Lubricating oil consisting of mineral oil,
A nonionic surfactant for emulsifying the lubricating oil and the silicone oil;
A lubricant comprising an organic molybdenum compound, and
A lubricating auxiliary agent comprising an organic zinc compound ,
The aqueous mold release agent composition whose particle diameter of the said silica is 10-20 nm.   The aqueous release agent composition according to claim 1, wherein at least a part of the surface of the silica is coated with aluminum. The aqueous release agent composition according to claim 1 or 2 , wherein the nonionic surfactant has an HLB of 7 to 14. The nonionic surfactant is a polyethylene alkyl ether;
Aqueous release composition according to any of claims 1 to 3 carbon atoms in the alkyl group of the polyethylene alkyl ether Ru der 12-22. The aqueous release agent composition according to any one of claims 1 to 4, wherein the organic molybdenum compound is at least one selected from the group consisting of molybdenum dithiocarbamate, molybdenum dithiophosphate, and a molybdenum-amine complex. The organic molybdenum compound contains a molybdenum atom and a sulfur atom;
And the content of said organic said molybdenum atoms molybdenum compound 1 molecular weight Atari is 4.5 or less mass%, according to any one of claims 1 to 5 the content of the sulfur atoms is not more than 5 wt% Aqueous release agent composition.   The aqueous mold release agent composition according to any one of claims 1 to 6, further comprising a cationic surfactant that is a tetraalkylammonium salt or an anionic surfactant that is an alkyl sulfate. The aqueous release agent composition according to any one of claims 1 to 7, wherein the lubricating auxiliary agent is zinc dialkyldithiophosphate.

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