JP2007253204A - Lubricating mold-release agent for casting mold and method for applying the same agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating mold-release agent for casting a mold, which molds a cast product having no blowhole on its surface and excellent luster, and to provide an applying method capable of achieving reduction in working time and the like. <P>SOLUTION: The lubricating mold-release agent for casting a mold has a flash point of 70-160°C and includes: (A) 50-90 mass% of solvent having a kinematic viscosity of 2-10 mm<SP>2</SP>/s at 40°C and having a flash point in the range of 70-160°C; (B) 1-10 mass% of high-viscosity mineral oil and/or synthetic oil having a kinematic viscosity of ≥100 mm<SP>2</SP>/s and ≤600 mm<SP>2</SP>/s at 40°C; (C) 0.1-3 mass% component of one or more kinds selected from the group of acrylic copolymer for improving wettability, acrylic modified polysiloxane having a flash point of ≤100°C, and extreme pressure agents; (D) ≤15 mass% silicone oil (D-1 component) for preventing seizing, which has a kinematic viscosity of ≥150 mm<SP>2</SP>/s at 40°C; and 1-10 mass% of additive (D-2 component) of one or more kinds having lubricating performance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lubricating mold release agent for die casting used for gravity casting and low pressure casting of non-ferrous metals such as aluminum, magnesium, and zinc, and a coating method thereof.

  As is well known, fried eggs are generally made by applying oil to a frying pan and pouring the mixed egg over it. Similarly, when casting a non-ferrous metal, a mold release agent is applied to the mold to prevent the mold and the molten metal from sticking, and the molten high temperature (eg, 450 ° C. or higher) is poured into the mold. After solidification, the product is removed. Currently, there are various methods for this casting. There are gravity casting, low-pressure casting, squeeze, and high-speed die casting when viewed from the pouring speed of the molten metal, and semi-solid casting is also added as viewed from the molten metal temperature.

  Considering the mold release lubricant, the flow rate of the molten metal during casting is a large factor, and if the flow rate of molten metal during casting is small, such as gravity casting, the molten metal for mold casting is lubricated and released. The time in which the mold is in contact is long, and the deterioration of the lubricant mold release agent for mold casting proceeds. As a result, when the coating film becomes thin and the molten metal solidifies, it may stick to the mold. Therefore, a “coating agent” obtained by adding water to inorganic powder is mainly used so as not to be affected by deterioration (see, for example, Patent Document 1). However, although the coating agent is not deteriorated, it contains water, and if the molten metal is poured before drying, there is a possibility of causing a steam explosion. For this reason, a drying process of several tens of minutes to several hours is indispensable after application, and the production efficiency becomes extremely low when “apply and produce every casting”.

  Therefore, the current situation is “apply once every tens or hundreds of pieces”. Moreover, application of the coating agent is said to be craftsmanship, and excellent craftsmen have a large number of products produced per application. In addition, the powder film made of the coating agent is partially peeled off and mixed into the product, and the strength of the product is extremely reduced. However, since it is unclear when peeling occurred, generally all products in the corresponding lot where peeling occurred are rejected and collected. When the coating pattern on the product design surface is peeled off, the peeled product part becomes convex, resulting in poor appearance.

  By the way, in the casting process, it is important not only to prevent sticking, but also to ensure that hot water completely flows into the finely engraved part of the mold and finishes the product of the expected mold. In order to secure this hot water flow, a thick coating agent is applied to slow down the cooling of the molten metal, keeping the viscosity of the hot water low, so that the hot water spreads through the details of the mold. As described above, it is applied once every several tens of times to ensure a thick coating film (thickness of several tens to several hundred microns), but a small amount of inorganic powder is brought into the product for each casting. The coating film for heat insulation becomes gradually thinner and the hot water flow cannot be secured. As a result, the metal crystal structure differs depending on the difference between the cooling rate of the initial product and the cooling rate immediately before coating, and there is a drawback in that the quality of the product differs between the initial stage and the later stage. That is, frequent application is required to stabilize the quality of the product, but drying after application is required, resulting in reduced production efficiency.

  In addition, the surface of a product made of a powder film generally has a satin-like shape, and some products do not satisfy the appearance quality requirements, and therefore a post-treatment for the purpose of polishing is necessary. In addition, since the coating film is an inorganic powder, scattering is unavoidable and attention should be paid to the working environment.

In addition, what was described in patent document 2, for example as an oil-based mold release agent which mix | blended the inorganic powder which does not deteriorate at 400 degreeC or more conventionally is known.
JP 59-169642 A Japanese Patent Laid-Open No. 2-117992

  In the case of a conventional water-soluble coating agent, “drying for several tens of minutes to several hours after coating” is indispensable. Efforts are being made to reduce the number of dryings with the aim of improving production efficiency. In consideration of the film thickness that is reduced by being caught in the molten metal every production, the initial coating film is excessively thickened, and “coating once every tens or hundreds of productions” is performed.

The present invention has been made in consideration of these circumstances, kinematic viscosity at 40 ° C. is at 2 to 10 mm ² / s solvent ranges flash point of 70 ° C. to 160 ° C., a kinematic viscosity at 40 ° C. is 100 mm ² / s One or more of high-viscosity mineral oil and / or synthetic oil of 600 mm ² / s or less, acrylic copolymer for improving wettability, acrylic-modified polysiloxane having a flash point of 100 ° C. or less, and extreme pressure agent, 40 By appropriately including a silicone oil having a kinematic viscosity at 150 ° C. of 150 mm ² / s or more and one or more additives having a lubricating performance, and having a flash point of 70 to 160 ° C., there is no skin nest of the cast product. It is another object of the present invention to provide a lubricating mold release agent for mold casting having good gloss.

  In addition, the present invention provides the mold release lubricant for mold casting by applying the mold release agent on the inner surface of the mold every casting or once or twice. Lubricating mold release for die casting that reduces the work time and avoids problems caused by film peeling due to excessive coating film thickness, and does not have the skin nest of the cast product and has good gloss. It aims at providing the coating method of an agent.

The lubricating mold release agent for mold casting according to the present invention is (A) 50 to 90% by mass of a solvent having a kinematic viscosity at 40 ° C. of ² to 10 mm ² / s and a flash point of 70 ° C. to 160 ° C. B) 1-10% by mass of a high-viscosity mineral oil and / or synthetic oil having a kinematic viscosity at 40 ° C. of 100 mm ² / s to 600 mm ² / s, (C) Acrylic copolymer for improving wettability, flammability 0.1 to 3% by mass of one or more components selected from the group of acrylic modified polysiloxane and extreme pressure agent having a point of 100 ° C. or lower, (D) at 40 ° C. for preventing seizure at high temperature 15% by mass or less of silicone oil (D-1 component) having a kinematic viscosity of 150 mm ² / s or more and 1 to 10% by mass of one or more additives (D-2 component) having lubricating performance, and having a flash point 70 to 160 ° C.

  The method for applying a lubricant mold release agent for mold casting according to the present invention is characterized in that the lubricant mold release agent for mold casting is applied to the inner surface of the mold every casting or once or twice. .

  ADVANTAGE OF THE INVENTION According to this invention, the lubrication mold release agent for die casting which does not have the skin nest of a cast product, and has favorable gloss can be provided. In addition, according to the present invention, compared with the prior art, it significantly reduces the time for applying and drying the release agent, thereby shortening the work time and avoiding problems caused by film peeling due to excessive film thickness of the coating film, Therefore, it is possible to provide a method for applying a lubricating mold release agent for die casting which has no skin of a good cast product and has a good gloss.

Hereinafter, the present invention will be described in more detail.
1. Quality of lubricant mold release agent for die casting
1) In gravity casting, the only force that pushes the molten metal to every corner of the mold is the weight of the molten metal. Therefore, it is necessary to devise a thick heat insulating film on the mold surface so that the molten metal does not cool and the molten metal flows to every corner of the mold. Therefore, it is necessary to ensure the thickness of the coating film and improve the hot water flowability. In other words, in order to ensure the thickness of the coating film, it is necessary to devise a method for increasing the amount of adhesion of the lubricant mold release agent for mold casting to the mold. By the way, there is a disagreement that the horizontal portion and the vertical portion are mixed in the mold, and the coating film in the vertical portion becomes thin. As a device for thickening the coating film in the vertical portion, it is conceivable to use the quick drying property adopted by the paint industry and to add volatility to the lubricant mold release agent for mold casting by mixing a solvent. As a method for thickening the coating film including the horizontal surface, it is preferable to add various additives having high adhesive strength described later.

2) It is necessary to improve lubricity and releasability in order to ensure hot water flow and not cause seizure / sticking problems when casting products are taken out. Lubricating additive (eg, vegetable oil effective at low temperature, molybdenum effective at intermediate temperature (eg, mold temperature 250-300 ° C.), silicone effective at high temperature (eg, mold temperature 300-370 ° C.) Oil and extreme pressure agent).
3) In consideration of the technical advantages and disadvantages described above, the present inventors have (A) 50 to 90 mass of a solvent having a kinematic viscosity at 40 ° C. of ² to 10 mm ² / s and a flash point of 70 ° C. to 160 ° C. %, (B) 1 to 10% by mass of high-viscosity mineral oil and / or synthetic oil having a kinematic viscosity at 40 ° C. of 100 mm ² / s to 600 mm ² / s, (C) Improves wettability to the mold surface In order to improve the adhesion of spray particles to the mold, acrylic copolymer, acrylic modified polysiloxane having a flash point of 100 ° C. or less and extreme pressure additive are 0.1 to 3 mass%, (D) at high temperature. 15% by mass or less of silicone oil (D-1 component) having a kinematic viscosity at 40 ° C. of 150 mm ² / s or more for preventing seizure and one or more additives (D-2 component) having lubricating performance. -10 mass%, with a flash point of 70-160 ° C Characterized Rukoto, led to explore the die casting lubricant release agent does not contain water.

The sprayable viscosity of the lubricant mold release agent for die casting is quite wide, but preferably ² to 450 mm ² / s at 40 ° C. Here, when the kinematic viscosity exceeds 450 mm ² / s, the particle diameter increases and the coating amount increases. On the other hand, when the kinematic viscosity is less than 2 mm ² / s, the spray pump is easily worn. Accordingly, it is practical to set the lower limit of the viscosity of kerosene to 2 mm ² / s. From the viewpoint of workability, volatility having a flash point higher than 70 ° C. which is the flash point of light oil for automobiles and 160 ° C. or less is preferable from the viewpoint of dryness.

  In addition, depending on the conditions of use, (E) an antioxidant is added to the above-mentioned lubricating mold release agent for mold casting to suppress oxidative deterioration of the coating film, and maintain a thick coating film for a longer period of time to reduce the hot water flow. It is preferable to keep.

  Further, when the high temperature contact time of the coating film is long or when the molten metal temperature is high (for example, 450 ° C. or higher), (F) inorganic powder may be added to further reinforce the coating film. Examples of the inorganic powder include non-black powder (F-1 component) and black graphite (F-2 component). Moreover, although the said oil-based mold release agent is described in the said patent document 2, it is a composition of a boronite powder, a clay type anti-settling agent, and a silicone oil, and is different from this invention.

2. Components of lubricant mold release agent for mold casting 1) A component
In order to form a thick oil film on the mold surface, it is better to vaporize the solvent as quickly as possible so that the high-viscosity component that has adhered once does not flow down from the mold, so a solvent with a high volatilization rate as seen in fast-drying paint (A component) is good. However, if the volatilization is fast, the flash point becomes low, and the risk of fire increases. Therefore, an excessively rapid volatilization such as gasoline is not preferable. Practically, it is higher than 43 ° C., which is the flash point of kerosene frequently used in the former oil-based mold release agent, and preferably higher than the flash point (70 ° C.) of light oil for automobile fuel. Also, if the volatility is low (the flash point is high), it is difficult to dry, so the low viscosity component A remains and the viscosity of the coating film becomes low, dripping flow from the vertical surface of the mold occurs, and the coating film becomes thin. As the volatility represented by the flash point, a solvent (component A) of 160 ° C. or lower is preferable.

  The amount of the solvent as component A is influenced by the amount of other components (B, C, D components) in addition to the viscosity and volatility, and is preferably 50 to 90% by mass. Here, the solvent of the component A is not necessarily one type of solvent, and a plurality of volatile solvents may be appropriately mixed.

A component is a high volatility and low viscosity component, and is a part which evaporates on the mold surface. Considering the influence on the human body, solvents with strong polarity such as alcohol, ester, ketone should not be used. Low-viscosity base oil (solvent that is a highly refined solvent that is petroleum-based and mostly paraffin-saturated solvent (solvent-1), with sulfur and nitrogen content kept extremely low, or slightly higher boiling point than solvent-1 -2) is preferred. The component A is “kinematic viscosity at 40 ° C. of ² to 10 mm ² / s”. When the viscosity is less than 2 mm ² / s, the viscosity of the entire mold release lubricant is too low, and the wear durability of the spray pump This is because if the A component exceeds 10 mm ² / s, the viscosity of the entire lubricant mold release agent for die casting increases, and the composition cannot be properly sprayed.

2) B component
Component B is a high-viscosity base oil and serves as a paste (binder) for attaching other components. The B component is preferably a high-viscosity hydrocarbon that does not easily evaporate at a high temperature, and a high-viscosity mineral oil and / or synthetic oil having a kinematic viscosity at 40 ° C. of 100 mm ² / s to 600 mm ² / s is blended. Examples of mineral oils include high-viscosity base oils and cylinder oils used in gear oils, and examples of synthetic oils include PAO (polyalpha-olefin) and ester base oils. Here, when the kinematic viscosity of the B component is less than 100 mm ² / s, the attached oil film is thin and the role of the glue is weakened. On the other hand, if the kinematic viscosity exceeds 600 mm ² / s, the viscosity of the lubricant mold release agent for mold casting becomes high and it becomes difficult to spray, and mixing work becomes difficult when producing the lubricant mold release agent for mold casting. Become. Moreover, the compounding quantity of B component has preferable 1-10 mass%. Here, when the blending amount is less than 1% by mass, the role of the paste is weakened. On the other hand, if the blending amount exceeds 10% by mass, a color residue phenomenon called “oil mark” in which “glue” is carbonized after casting occurs, resulting in defective casting products.

3) C component
Component C is a wettability improver, and includes hydrocarbons having weak polarity and compounds thereof. For example, a total of 0.1 to 3% by mass of at least one component selected from the group of acrylic copolymers, acrylic modified polysiloxanes having a flash point of 100 ° C. or less, and extreme pressure agents (extreme pressure additives) such as sulfurized esters Can be included. When the wettability improver is added, the wettability of the mold casting lubricating mold release agent to the mold surface is improved, and the mold casting lubricating mold release agent is easily placed on the mold surface. In particular, when the mold surface becomes high temperature, oil droplets do not wet the mold surface (Leidenfrost phenomenon) due to the rapid boiling of the light components of the mold release lubricant, and the oil film on the mold surface. Inhibits formation. However, when there is a wettability improver, the wettability is improved, so this phenomenon is suppressed and an oil film is formed thick. The acrylic copolymer itself has a dispersing ability and also has the ability to disperse the F component powder.

4) D component
The D component is a lubricant that reduces friction. The temperature at which seizure occurs in the mold varies depending on the operating conditions. In gravity casting, the operating temperature range is approximately 200 to 450 ° C. Therefore, the additive for the lubricant mold release agent for mold casting has lubricity in a wide temperature range. It is necessary to grant. However, with the exception of powder, this wide area cannot be covered with a single additive. Therefore, it is necessary to divide the temperature region and cover with about two types of additives.

As the first additive group (component D-1), 15% by mass or less of a silicone oil having an effect of preventing seizure at about 300 to 370 ° C., although the friction coefficient is not so low. Here, since the silicone oil is expected to have lubricity at a high temperature, a high viscosity silicone oil having a “kinematic viscosity at 40 ° C. of 150 mm ² / s or more” is preferable. If the cast product is not painted, any commercially available silicone oil including dimethyl silicone may be used. However, when painting, it is difficult to place the coating, so dimethyl silicone oil is not preferred depending on the amount of coating. In the case of painting, as the silicone oil, for example, alkyl aralkyl or alkyl silicone oil having an alkyl group longer than dimethyl is preferable.
The reason why the D-1 component is set to “15% by mass or less” is that when it exceeds 15% by mass, silicone or a silicone decomposition product is deposited on the mold, which adversely affects the shape of the cast product. However, the amount of silicone oil is preferably reduced from the viewpoint of cost.

  As a 2nd additive group (D-2 component), for example, animal and plant type fats and oils (for example, rapeseed oil, soybean oil, coconut oil, palm oil, beef oil, lard, etc.) which give a low friction near 150-300 ° C Animal and vegetable oils and fats, fatty acid esters), organic acids (coconut oil fatty acids, oleic acid, stearic acid, lauric acid, palmitic acid), alcohol esters (esters of higher fatty acids such as beef tallow fatty acids), organic molybdenum, oil-soluble soaps, oily A wax is mentioned.

  As the organic molybdenum, for example, MoDDC and MoDTC are preferable, and MoDDP and MoDTP in which aluminum and phosphorus may react are less preferable. Examples of oil-soluble soaps include Ca or Mg sulfonate salts, finate salts, and salicylate salts, and organic acid metal salts, although there are difficulties in solubility. Further, there are extreme pressure agents that are slightly corrosive but can prevent seizure at high temperatures. Sulfur oils and sulfur esters are preferred. SP-based ZnDDP is odorous and chlorine-based corrosion is caused by reaction with metals and should be avoided. 1-10 mass% of 1 or more types of additives (D-2 component) which have these lubricity are added.

5) E component
E component is an antioxidant. By mix | blending 0.2-2 mass% of antioxidant mentioned later, deterioration of the lubricous mold release agent for metal mold | die casting is suppressed. As a result, the initial oil film thickness can be maintained, the heat insulation is improved, and the hot water flow is finally improved. Antioxidants can be classified into three types, and one or two or more types can be blended.

  As the first group of amine-based antioxidants, for example, monoalkyldiphenylamines such as monononyldiphenylamine, 4,4′-dibutylphenylamine, 4,4′-dipentyldiphenylamine, 4,4′-dihexyldiphenylamine, 4, Polyalkyldiphenylamines such as 4'-diheptyldiphenylamine, 4,4'-dioctyldiphenylamine, dialkyldiphenylamines such as 4,4'-dinonyldiphenylamine, tetrabutyldiphenylamine, tetrahexyldiphenylamine, tetraoctyldiphenylamine, tetranonyldiphenylamine , A-naphthylamine, phenyl-a-naphthylamine, butylphenyl-a-naphthylamine, pentylphenyl-a-naphthylamine, hexylphenyl-a-naphth Tylamine, heptylphenyl-a-naphthylamine, octylphenyl-a-naphthylamine and the like can be mentioned.

Examples of the second group of phenolic antioxidants include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 4,4-methylenebis ( 2,6-di-tert-butylphenol), 2,2-methylenebis (4-ethyl-6-butylphenol), high molecular weight monocyclic phenolic, polycyclic tertiary butyl phenol, BHT (Butylated Hydroxylene Toluene), BHA (Butylated) Hydroxy Anisole).
Examples of the third group of cresol antioxidants include ditertiary butyl paracresol and 2-6-ditertiary butyl dimethylamino-p-cresol.

6) F component
The F component is an inorganic powder and consists of an F-1 component group and an F-2 component group. In the temperature range exceeding 400 ° C., the above B, C, D and E components decompose in a short time. Although there are additives that retain releasability even when decomposed, the coating film becomes thin and the heat insulating properties are reduced. The inorganic powder described later hardly deteriorates at high temperatures, and forms a thick powder film to exhibit heat insulation.

The F-1 component group is an inorganic powder that is not relatively black (that is, at least one type such as white, gray, or red), and the blending amount is preferably 1 to 10% by mass. If the blending amount of the inorganic powder exceeds 10% by mass, the product settles before using the mold release lubricant and causes a quality problem, and the gloss of the cast product deteriorates. Also, the work site becomes dirty with powder. When the blending amount is less than 1% by mass, the effect at high temperature is small. Examples of inorganic powders include talc, mica, mica, clay, organoclay (a small amount of organic matter added to clay), refractory mortar, boronite, sericite, CaCO ₃ , borate, alumina powder, pyrroline. Examples include acid salts, sodium bicarbonate, titanium oxide, bengara, radiolite, and zirconium oxide.

  Examples of the F-2 component group include at least one inorganic powder of graphite, carbon black, and diamond powder. Although the lubricity is superior to the F-1 component, the work site is very dirty. Therefore, it is preferable to add 10% by mass or less of these inorganic powders. Even if 2% by mass or more of graphite is blended in the region where D component silicone oil is present, the lubricity is not so improved, but up to 10% by mass may be blended in order to increase the thickness of the powder film.

In addition, a dispersant may be added to uniformly disperse the inorganic powders as the F-1 and F-2 components in the oil.
When the blending amount of the above B, C, D, and E components is maximized and the inorganic powder of the F component is minimized, contamination at the work site is reduced, which is a merit for the user.

3. Application method
According to the second aspect of the present invention, as described above, the method of applying the lubricant mold release agent for casting the mold is applied to the inner surface of the mold every casting or once or twice. It is characterized by applying. Hereinafter, this coating method will be described.
1) In the case of the conventional water-soluble coating agent, as described above, the initial coating film is excessively thickened in consideration of the film thickness that is reduced by the inorganic powder being involved in the molten metal every production. Or “apply once every several hundred pieces”. In the case of the present invention, unlike a water-soluble coating agent, an oil-based lubricating mold release agent for mold casting is applied to the inner surface of the mold every casting (every time application) or once or twice. Here, in the present invention, “every application” is possible because, for example, “after application for 1-2 seconds, drying for a few seconds”. In the case of the present invention, even if the casting is performed 100 times, the total of coating and drying is about 10 minutes, and the working time is much shorter than several tens of minutes to several hours of the water-soluble coating agent. In addition, when apply | coating the lubricous mold release agent for metal mold | die castings, it is preferable to keep the application quantity to the minimum.

As a result, the following merits a) to f) can be expected.
a) The drying process is short, the mold can be used for production, and downtime is reduced.
b) By spraying each time, the skill difference of the paint craftsman is minimized, and the quality is stabilized.
c) The thickness of the coating film becomes uniform by spraying each time, and the quality of the cast product is stabilized.
d) Since it is not necessary to make the coating film excessively thick as in the conventional method, the risk of failure due to peeling can be reduced.
e) Since the excessive film thickness is eliminated and the film thickness is the minimum necessary, the cooling property is improved.
f) Solidification occurs in a short time, the metal crystal becomes fine, and a tough product is obtained.

  In place of “every time application” of the present invention, the mold release lubricant for mold casting of the present invention may be applied once or twice (applied intermittently). Therefore, it is necessary to make the coating film slightly thicker. Here, an excessive coating film may lead to generation of gas due to partial thermal decomposition, a problem of a cast hole, and a reduction in strength of a product. Therefore, it is most preferable to apply each time in order to obtain the minimum necessary coating thickness.

  2) As mentioned above, when sprayed every time, the drying must be fast every time. Therefore, high volatility is imparted in order to eliminate water from the mold release lubricant for mold casting of the present invention and to speed up drying.

Examples of the present invention will be described below.
(A) Explanation of figure
First, a molten aluminum flowability evaluation tester used in the examples of the present invention and a formability evaluation tester imitating gravity casting will be described.
FIG. 1 shows a schematic perspective view of a hot water flow tester. 2A is a front view of a stand that is one configuration of the hot water flow tester of FIG. 1, FIG. 2B is a side view of FIG. 2A, and FIG. 3A is a hot water flow test of FIG. 3 (B) is a side view of FIG. 3 (A), FIG. 3 (C) is a bottom view of FIG. 3 (A), and FIG. 3 (D) is FIG. Sectional drawing which follows the XX line of C) is shown. 4 (A) is a perspective view of a bowl as one configuration of the hot water flow tester of FIG. 1, FIG. 4 (B) is a bottom view of FIG. 4 (A), and FIG. 5 is one of the hot water flow tester of FIG. The front view of the stick | rod which is a structure is shown.

  The hot water flow tester includes an iron base 1, an iron lid 2 placed on the base 1, an isolite brick fence 3 placed on the lid 2, It consists of a brick rod 4 and a gas burner 5. As shown in FIGS. 1 and 2, the table 1 includes a protruding portion 1a protruding upward in one end side along the longitudinal direction, and a tapered surface 1b is formed on the protruding portion 1a. A taper surface 2a is formed at a portion in contact with the base 1 on one end side of the lid 2 as shown in FIGS. 1 and 3A. As shown in FIGS. 3C and 3D, a groove 2b for flowing molten metal is formed on the tapered surface 2a of the lid 2, and a groove 2c communicating with the groove 2b is formed on the lower surface.

  A handle 6 is attached to the top of the lid 2. The trough 3 is formed with an opening 7 for supplying a molten metal and a hole 8 communicating with the opening 7. The flange 3 is placed on the lid 2 so that the hole 8 of the flange 3 is positioned in the groove 2b of the lid. The tip of the rod 4 has a conical shape as shown in FIG. 5, and this portion is set on the rod 3 so as to block the hole 8 of the rod 3. The rod 4 is configured such that the tip of the rod 4 is inserted into the hole 8 before the molten metal is accommodated in the trough 3, and the rod 4 is lifted upward when flowing the molten metal into the grooves 2b and 2c of the lid 2. Yes.

  The formability evaluation tester is configured as shown in FIGS. 6, 7 and 8. Here, FIG. 6A shows a front view of the first mold, and FIG. 6B shows a plan view of the first mold. FIG. 7A is a front view of the second mold, and FIG. 7B is a plan view of the second mold. FIG. 8 shows an explanatory diagram when the first mold and the second mold are heated.

  As shown in FIG. 6, the iron-made first metal mold 11 communicated with the notch 12a having a semicircular cross section for forming a pouring gate 12 for pouring the molten metal, and the notch 12a. , A product-shaped cavity 13 is engraved. The cavity portion 13 has six ribs branched right and left, and is composed of a total of 18 cells 14a, 14b, 14c, 14d, 14e, 14f,. The numbers in the cells in FIG. 6B indicate the thickness of each cell, and the thicknesses are different on the left side and the right side. For example, the left cells 14a, 14b, and 14c have thicknesses of 10 mm, 8 mm, and 6 mm, respectively, while the right cells 14d, 14e, and 14f have thicknesses of 6 mm, 4 mm, and 2 mm, respectively. As shown in FIG. 7, the second metal mold 15 made of iron is flat except for the cutout portion 12 b having a semicircular cross section. Note that the notches 12a and 12b are combined to form the gate 12 shown in FIG. The inner surface of the first mold 11 and the inner surface of the second mold 15 are heated to a predetermined temperature by a burner 16 as shown in FIG.

(B) Manufacturing method
A high-viscosity base oil, silicone oil, wettability improver, and lubricant additive were mixed at a mass% shown in Table 1 below, and then heated to 40 ° C. and stirred for 10 minutes. Next, the solvent was added to these mixtures by mass% shown in Table 1, and the mixture was stirred again for 10 minutes to produce a lubricating mold release agent for gravity casting as a sample. According to the purpose, antioxidant, powder and graphite were mixed in the first step.

However, in Table 1,
Solvent-1: Product name of Shell Chemical: Shellzol ™
Solvent-2: UBJ trade name: Y-base-2
High-viscosity mineral oil: Japan Energy's brand name: Bristock
Silicone oil: Asahi Kasei Wacker Silicone brand name: Release agent TN
Rapeseed oil: Trade name of rapeseed oil industry: Rapeseed oil
Organic Molybdenum: Asahi Denka Kogyo's trade name: Sakurarubu 165
Acrylic copolymer: Wilba Ellis trade name: EFKA-3778
Ca soap: Infineum brand name: M7101
Sulfide ester: Kozakura Shokai brand name: GS-230
(C) Test method
(C-1) Flash point measurement method
The flash point of the sample was measured according to the JIS-K-2265 by the pen schulten ten method.
(C-2) Kinematic viscosity measurement method
The kinematic viscosity at 40 ° C. of the lubricant release agent containing no powder was measured according to JIS-K-2283. Moreover, in the case of the lubricating mold release agent containing powder, the kinematic viscosity at 40 ° C. was calculated from the absolute viscosity (cP) at 40 ° C. and the specific gravity measured with a rotational viscometer based on JIS-K-7117-1.

(C-3) Lab oxidation test, ROBT method
In accordance with JIS-K-2514, a sample was taken in a rotary sealed pump, and after that, oxygen was sealed, oxidized under a condition of 150 ° C., and the time until a sudden decrease in oxygen pressure was measured.

(C-4) Hot water flow evaluation test
The operation of the hot water flow evaluation test by the hot water flow evaluation tester in FIG. 1 is as follows.
First, the iron homemade test stand 1 and the lid 2 are separately placed on the burner 5 and heated to a predetermined temperature (230 ° C. in the embodiment). Further, the scissors 3 and the rod 4 are heated to about 500 ° C. by another burner 5. When the base 1 and the lid 2 reach a predetermined temperature, a mold release lubricant is applied to the groove 2c of the base 1 and the lid 2, and the lid 2 is placed on the base 1 by grasping the handle 6 of the lid 2. Put on. The scissors 3 are placed so that the hole 8 matches the groove 2a portion of the lid 2, and the hole 8 is closed with a stick 4 and plugged. Separately, 90 cc of molten aluminum (AC4CH material, temperature 700 ° C.) melted in a melting furnace for ceramics is collected with an iron handle, and immediately poured into the bowl 3. After 2 seconds, the rod 4 is removed from the hole 8 and the molten metal is poured into the tester. After 30 seconds, the lid 2 is separated from the table 1 and the length of the aluminum solidified on the table 1 is measured. If it flows for a long time, the hot water flow is judged to be good.

(C-5) Formability evaluation test
The operation of the moldability evaluation test by the moldability evaluation tester of FIGS. 6 to 8 is as follows.
First, as shown in FIG. 8, the first mold 11 and the second mold 15 are heated to a predetermined temperature by separate burners 16. Next, a lubricating mold release agent for mold casting is applied to the inner surfaces of the first mold 11 and the second mold 15, and after a few seconds, as shown in FIG. Match the mold 15. Subsequently, the molten aluminum 18 (AC4CH, 700 ° C.) is drawn from the melting furnace with the iron handle 17 and the molten aluminum 18 (about 2.8 kg) is poured from the spout 12. After aluminum solidification (about 2 minutes), the first mold 11 and the second mold 15 are divided, and the cast product 19 (shown in FIG. 10) solidified by the first mold 11 is taken out. The number of portions 20 having different thicknesses transferred from a cell in which the cavity is completely filled with the cavity is obtained. If the number of completely shaped portions 20 is large, it is judged that the moldability is good and the hot water flowability is good.

(D-1) Test measurement results: no antioxidant / no powder
Table 1 shows the components of Examples 1, 2, and 3, physical property values, hot water flow evaluation test results, coating amounts, and moldability evaluation test results.
Table 2 below shows the components, physical properties, molten metal flow evaluation test, coating amount and moldability evaluation test in Comparative Examples 1 to 4. In Table 2, the comparative example 1 is an oil-based mold release agent for die casting manufactured by the present applicant, the comparative example 2 is a representative water-soluble coating agent made by other companies currently used in gravity casting, the comparative example 3 Is a ladle coating agent made by the applicant, a type of coating agent used by some companies as a coating agent repair / reinforcement agent. Example 4 shows a blank of “no coating agent / no lubricating release agent”.

However, in Table 2,
"-" Mark: No measurement
Oil-based mold release agent: Aoki Scientific Research Institute trade name: WFR-3R
Water-soluble coating agent: Sanwa Yuka's trade name: Sun Value MR-W14
Ladle coating agent: Aoki Scientific Research Institute product name: Slick Liner # 3, containing a large amount of inorganic metals. Similar to water-soluble coating agents, it is an anti-sticking agent for ladle and molten metal.

Examples 1, 2, and 3 and Comparative Example 1 are oily without water, and have a flash point of 70 ° C. or higher and a kinematic viscosity at 40 ° C. of 450 (mm ² / s) or less. Comparative Examples 2 and 3 are water-soluble, and the drying process takes several tens of minutes to several hours, or the estimated viscosity is several hundred to several thousand (mm ² / s), which is difficult to spray and difficult to automate. There is a problem.

  In the case of Comparative Example 4 where nothing was applied, the molten metal flowed only 30 mm, but in the case of Comparative Example 2 of a typical water-soluble coating agent, it flowed as much as 400 mm. When casting is continued, the powder is gradually taken into the cast product and the film thickness is reduced. For example, the defective product comes out about 50 μm, so the initial film thickness is 150 μm, which is about 3 times thicker. That is, since the coating film was excessively thick at the initial stage, the heat insulating film was thick, the melt temperature was kept high without being lowered, and the melt viscosity was kept low. As a result, the melt flowed as long as 400 mm. The goal of this study is to apply the oil film every time with the oil film thickness just before the defective product comes out. When a hot metal flowability evaluation test was performed using a ladle coating agent manufactured by the present applicant, which had good availability, it flowed about 240 mm as shown in Comparative Example 3. This level was used as a guide for this study. As shown in Comparative Example 1, the oil-based mold release agent for die casting had a hot water flow of 50 mm and was almost the same as the blank. It can be said that the oil film is extremely thin (when measured only once with an expensive oil film thickness meter, the oil film thickness was 3 μm). Compared with Comparative Example 1, Examples 1, 2 and 3 contained many oil-soluble additives, and when an acrylic copolymer, Ca soap or sulfide ester was added, the hot water flow was improved.

  Furthermore, it evaluated with the moldability evaluation tester (refer C-5 term) of the conditions nearer to an actual machine. The shape of the product cast by this tester is “3 pairs, total of 6 ribs”. Each rib on the left side has three thicknesses of 10, 8, and 6 mm toward the tip, and the right side is the tip. The thickness is 6 mm, 4 mm and 2 mm. Since the cells are divided into 18 divisions in total, the measurement result is represented by “the number of the divisions”, and “18” is the best. In the case of the water-soluble coating agent of Comparative Example 2, it is a good value of 18 pieces. On the other hand, in Comparative Example 1 of the oil-based mold release agent for die casting, only 5 pieces flow. Apparently, the hot water flow is inferior. In Example 2 containing acrylic copolymer and Ca soap, 12 pieces still have insufficient hot-water flow, but are considerably better than Comparative Example 1. In Example 2, the number of times of application of 2 cc is “one application”, but in Example 1, the same composition was used, and “number of times of application of 2 cc was 3 times (total application amount 6 cc)”. It became "18" and became favorable. Further, Example 3 is different in composition from Examples 1 and 2, but when “the number of times of application with a coating amount of 2 cc is set to 2 times (total coating amount of 4 cc)”, the hot water flow is as good as “18 pieces”. It was. In addition, the coating amounts of the water-soluble coating agent and the ladle coating agent in Comparative Examples 2 and 3 were several times larger than 6 cc in Comparative Example 1.

FIG. 11 is a diagram schematically showing a photograph of the part obtained in Example 2 described above. From FIG. 11, according to Example 2, it was confirmed that ₁₂ portions 20 _{1 to} 2012 having different thickness transferred from each cell and no chip were obtained.

  Regarding the gloss of the skin of the cast product, in the case of the representative coating agent of Comparative Example 2, gray is not good, but in the case of the oil-based lubricating release agents of Examples 1, 2 and 3, the gloss is increased. On the other hand, with respect to the skin nest of the cast product, Comparative Example 2 (water-soluble coating agent) containing almost no organic matter is the best, and in the case of the oil-based lubricating release agents of Examples 1, 2, and 3, the comparison is made. Although slightly inferior to Example 2, it shows a good appearance.

(D-2) Test measurement results: Effect of antioxidant
Table 3 below shows the results of the components, physical properties, and hot water flow evaluation tests of Examples 4 and 5 and Comparative Example 5.

However, in Table 3,
Phenolic antioxidants: Daiichi Kogyo Seiyaku brand name: Rasmit BHT
Amine-based antioxidant: Afton Chemical's trade name: HiTEC-569
The other components are the same as in Table 1. As shown in Table 3, the flash point of Example 4 is 70 ° C. or higher, and the kinematic viscosity at 40 ° C. is 450 (mm ² / s) or less. Moreover, when the oxidation resistance performance in the laboratory oxidation test was measured, in the case of Comparative Example 5 (without organic molybdenum and antioxidant), the measured value of the degradation time was as short as 15 minutes and was immediately oxidized. In the case of Example 4 (both organic molybdenum and antioxidants are present), the deterioration time is 890 minutes, which is about 60 times longer than that of Comparative Example 5, and hardly deteriorates. Therefore, in the case of Example 4, it was confirmed by the laboratory oxidation test that the antioxidant suppressed the oxidative deterioration of the oil-based lubricant release agent.

  On the other hand, regarding the hot water flow length in the hot water flow evaluation test, the comparative example 5 (without organic molybdenum and antioxidant) is as short as 50 mm, and in the case of Example 4 (with organic molybdenum and antioxidant). It began to flow as long as 120 mm.

  If an antioxidant is added to increase the anti-oxidation property of the lubricant mold release agent for die casting, the coating film adhering to the hot water flow evaluation tester becomes difficult to oxidize, maintaining the thickness of the coating film and improving the heat insulation. It is estimated that the temperature of the molten metal is lowered and the viscosity of the molten metal is kept low, and as a result, the molten metal flows for a long time. However, the flow of hot water is still insufficient with the addition of antioxidant alone, and it is desirable to use it together with other additives such as extreme pressure agents and powders.

(D-3) Test measurement result: When containing inorganic powder
Table 4 below shows the results of the components, physical properties, molten metal flow property evaluation test and moldability evaluation test of Examples 6, 7, and 8 which are lubricant mold release agents containing powder. Table 5 below shows the results of the components, physical properties, molten metal flow evaluation test, and moldability evaluation test of Examples 9, 10, 11, and 12 that are powder mold-containing lubricant mold release agents. As shown in Tables 4 and 5, the flash points of Examples 6 to 12 are in the preferred range of 70 ° C. or higher and the kinematic viscosity at 40 ° C. of 450 (mm ² / s) or lower.

However, in Table 4,
Organoclay: Wilba Ellis's trade name: Galamite 1598
Graphite: Product name of Chuetsu Graphite: A mixture of 3 parts of 96L-3 (scale-like) and 7 parts of 150F (soil-like)

However, in Table 5,
Aluminum powder: Asian aluminum products: Alpaste 100M
Diamond powder: Higuchi Shokai's product name: Cluster diamond solvent solution
Others were the same as in Table 1 and Table 4, and the hot water flow evaluation was improved by increasing the coating amount even with the same composition. Even in the case of the lubricating mold release agent for mold casting containing graphite and organoclay, it was 150 mm at 1 cc in Example 10 and 200 mm at 2 cc in Example 9, but 260 mm at 6 cc in Example 6. Further, in Example 7 in which the amount of graphite was increased, the hot metal flowability was further increased to 300 mm. In Example 8 in which Ca soap or sulfide ester is used instead of graphite, the hot water flow is slightly reduced. The goodness of graphite was confirmed, but even if graphite is not used, the flowability of hot water is as good as 250 mm. Therefore, it is predicted that the oil film is thick with organic clay, soap, and sulfide ester. On the other hand, in Example 11, in place of the graphite of Example 9, nanomicron-sized diamond powder was evaluated. Since the graphite of Example 9 is better in hot water flowability, it is estimated that if the particles are large to some extent, a thick film is formed and the hot water flowability is improved. Moreover, when the result of Example 9 and Example 12 which compared graphite with aluminum powder was seen, the direction of hot water was better in graphite than in aluminum powder. There is a possibility that graphite is easier to adhere to the mold than aluminum powder, and that heat insulation is small, so heat insulation is good.

  Even in the evaluation by the moldability evaluation tester, 18 mold release lubricants containing the powders of Examples 6, 7, and 8 flowed, and good performance was confirmed. And the skin of the cast product was excellent in Examples 6 and 7 containing graphite. Examples 6 and 7 containing powder are better for the skin of the cast product than in Examples 1, 2 and 3 containing no powder. In the case of a lubricating mold release agent for mold casting containing powder, a gap is formed between the oil and the cast product, and a decrease in the formation of the cast hole due to escape of the gas generated by the oil appears on the skin of the cast product. Conceivable. In particular, the gloss of graphite was good. The other powders (F-1 component) are hard, and it is presumed that a slightly satin pattern is formed on the surface of the cast product and becomes cloudy, and the gloss is slightly reduced.

  The lubrication mold release agent for mold casting of the present invention is suitable for automatic continuous spraying during gravity casting, coating of undiluted solution and trace amount, and also suitable for lubrication of the mold surface. In low-pressure casting using water-soluble coating agents, the speed of the molten metal is slightly faster than that of gravity casting, so the time during which the lubricant release agent is in contact with the high temperature is shortened. The agent is suitable. Furthermore, the lubricating mold release agent for mold casting is suitable for application to the inner surface of the mold every casting or once or twice.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, you may delete some components from all the components shown by embodiment. Specifically, various materials and blending amounts used for the lubricant mold release agent for die casting may be appropriately set within the range described in the above-mentioned column “Best Mode for Carrying Out the Invention”. it can. Furthermore, constituent elements over different embodiments may be deleted. Furthermore, you may combine the component covering different embodiment suitably.

FIG. 1 shows a schematic perspective view of a hot water flow tester. FIG. 2 is an explanatory view of a table which is one configuration of the hot water flow tester of FIG. FIG. 3 is an explanatory diagram of a lid which is one configuration of the hot water flow tester of FIG. FIG. 4 is an explanatory view of a bowl which is one configuration of the hot water flow tester of FIG. FIG. 5 is an explanatory view of a bar which is one configuration of the hot water flow tester of FIG. FIG. 6 is an explanatory diagram of a first mold used in the moldability evaluation tester. FIG. 7 shows an explanatory diagram of a second mold used in the moldability evaluation tester. FIG. 8 is an explanatory diagram when heating the first mold and the second mold. FIG. 9 shows a state when the first mold and the second mold are integrated. FIG. 10 shows a plan view of the product solidified in the first mold. FIG. 11 schematically shows a photograph of the product obtained in Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stand, 1a ... Projection part, 1b, 2a ... Tapered surface, 2 ... Cover, 2b, 2c ... Groove, 3 ... Rod, 4 ... Bar, 5 ... Gas burner, 6 ... Handle, 7 ... Opening, 8 ... Hole 11, first mold 12, gate 12, cavity portion 14, 14 a, 14 b, 14 c, 14 d, 14 e cell 15, second mold 16, gas burner 17, handle 18 ... molten metal, 19 ... cast product, 20, 20 _{1 to} 20 ₁₂ ... part.

Claims (4)

(A) 50 to 90% by mass of a solvent having a kinematic viscosity at 40 ° C. of ² to 10 mm ² / s and a flash point of 70 to 160 ° C., and (B) a kinematic viscosity at 40 ° C. of 100 mm ² / s to 600 mm. 1 to 10% by mass of a high viscosity mineral oil and / or synthetic oil of ² / s or less, (C) an acrylic copolymer for improving wettability, an acrylic-modified polysiloxane having a flash point of 100 ° C. or less, and an extreme pressure agent (1) A silicone oil having a kinematic viscosity at 40 ° C. of 150 mm ² / s or more for preventing seizure at a high temperature (D−). 1 component) 15% by mass or less and one or more additives (D-2 component) having a lubricating performance of 1 to 10% by mass and having a flash point of 70 to 160 ° C. Lubricating mold release agent. 2. The mold according to claim 1, comprising 0.2 to 2 mass% of one or more selected from the group consisting of amine-based, phenol-based and cresol-based antioxidants as component (E). Lubricating mold release agent for casting. As component (F), 1 to 10% by mass of at least one inorganic powder of white, gray or red and 10% by mass or less of at least one inorganic powder of graphite, carbon black or diamond powder. The lubricating mold release agent for die casting according to claim 1 or 2, characterized in that: A lubricated mold release agent for mold casting according to any one of claims 1 to 3, wherein the lubricant mold release agent for mold casting is applied to the inner surface of the mold every casting, once or twice. Agent application method.

Images