JP2020097439A - Steel drum can mouthpiece and steel drum can - Google Patents

Abstract

To provide a steel drum can mouthpiece and a steel drum can that can suppress white rusting generation at a mouthpiece flange and a plug of the steel drum can at a low cost, and have anti-staining property with respect to a storage object.SOLUTION: A steel drum can mouthpiece 100 attached to a top plate 11 of a steel drum can is provided with a mouthpiece flange 110, and a plug 120 screwed to the mouthpiece flange. The steel drum can mouthpiece is plated with an unichrome plating 50, and further has a white rusting suppressing film 210 that is covered with the unichrome plating to suppress white rusting generation. A coating agent that forms the white rusting suppressing film 210 includes a resin 202, a metal oxide 204, and a surface conditioner 208, and is a water-soluble composition that can be dried and formed into a film at a temperature that does not deteriorate the unichrome plating.SELECTED DRAWING: Figure 2

Description

The present invention relates to a steel drum can, and more particularly, to a steel drum can base provided on a top plate of a steel drum can and having a rust preventive treatment, and a steel drum can having the base.

In a tight-head steel drum, which has an internal capacity of about 200 liters and a top plate is wound around the body plate, as specified in JIS Z 1601, the top plate has an inlet and a ventilation port used for putting in and out of the contents. It is provided. The injection port and ventilation port are composed of a base flange attached to a hole formed in the top plate and having a female screw, and a plug having a male screw that is screwed into the female screw. The mouth is closed and opened.

The so-called unichrome plating is usually formed on such a base flange and a plug for the purpose of rust prevention and the like, and because it is inexpensive, it is plated with zinc and then subjected to bright chromate treatment.

JP-A-4-239448

The above-mentioned unichrome-plated inlet and ventilation port have the following problems peculiar to steel drums due to the article called steel drums.
That is, regarding the storage of steel drums, the drum can manufacturer recommends indoor storage, but users often store them outdoors due to problems such as storage space, and in reality, they are exposed to rainwater. This is the same during transportation. Due to the presence of such water, zinc in galvanization reacts with water, and so-called white rust (composite of zinc hydroxide and zinc carbonate) is often generated on the base flange and the plug. Further, it is known that this reaction rapidly proceeds in a temperature range of 40° C. or higher.
Such white rust impairs the appearance of the injection port and the ventilation port, and at the time of opening the plug, white rust may enter the can and become foreign matter. Therefore, white rust is one of the important issues to be solved in steel drums.

Further, in order to prevent moisture from being applied to the base flange and the plug, it is also possible to cover the inlet and the ventilation port with metal cap seals. Such a cap seal is provided for the purpose of protecting and sealing the cap flange and the plug (preventing the theft of the contents), and is often mounted on the user side after the contents are filled into the can. It may occur. If it is not properly installed, rainwater will easily enter the cap seal during transportation and outdoor storage of the steel drum. Once water enters the cap seal, the cap seal is adversely affected and water is less likely to evaporate. In the summer and the like, the inside of the cap seal becomes hot and humid, which often causes remarkable white rust.

As a measure for preventing the above-mentioned white rust, there is a method of changing the mouth flange and the plug to a stainless steel material which does not require anticorrosion treatment, but the cost is high. That is, the steel drum can is an article that is required to be set at a low overall price, and therefore expensive parts cannot be used in terms of cost. Further, by using the stainless steel parts, chips may be generated due to so-called galling or the like peculiar to the stainless steel material.
There is also a method of making the plug made of resin, but the resin plug may be scraped or damaged when it is screwed into the female screw of the metal base flange, and the above-mentioned risk of foreign matter mixing occurs. ..

There is also a method of coating a solid lubricant having a high hardness and good adhesion with a base, such as is performed in the field of automobiles, but the solid lubricant is expensive and, as described above, in terms of cost. It is difficult to use in steel drums.

Further, as a problem peculiar to the steel drum can, there is a problem that the can inner surface portion of the mouth flange and the plug comes into contact with the drum can contents. Therefore, the rust-preventing treatment for the base flange and the plug is also non-contaminating, that is, non-contaminating to the contained items, such as elution of the rust-preventive coating into the contained items or peeling of the rust-preventive coating. Required.

The above-mentioned Patent Document 1 discloses a coating material that reduces the loss of the coating film and the cutting powder on the plug and flange of the drum can, but the coating material contains an epoxy resin or a phenol resin as a main component, and the thickness thereof. This is different from the present application. That is, the above-mentioned epoxy resin or the like is a thermosetting resin, and baking at a high temperature such as 200° C. is required to form a coating film. In this regard, the above-mentioned unichrome plating applied to the base flange and the plug, particularly the chromate film, has a problem of poor heat resistance.

The present invention has been made in order to solve such a problem, the suppression of white rust occurrence in the base flange and plug of the steel drum can, it is possible to achieve at low cost, and further has a non-polluting property to the contained objects, An object is to provide a steel drum can base and a steel drum can.

In order to achieve the above object, the present invention is configured as follows.
That is, a steel drum can base according to one aspect of the present invention is a base mounted on a top plate of a steel drum, and includes a base flange and a plug screwed to the base flange, and is made of unichrome-plated steel. A mouthpiece for drums,
The unichrome plating is further provided with a white rust suppressing film that suppresses the occurrence of white rust, and the white rust suppressing film contains a resin and a metal oxide and can be formed at a temperature that does not deteriorate the unichrome plating. The water-soluble coating agent is dried and formed into a film.
Further, a steel drum can base according to another aspect of the present invention is a base attached to a top plate of a steel drum, and includes a base flange and a plug screwed to the base flange, and is a unichrome plated steel. A mouthpiece for drum cans,
The unichrome plating is further provided with a white rust suppressing film that suppresses white rust generation, and the white rust suppressing film contains a resin, a metal oxide, and a surface modifier at a temperature that does not deteriorate the unichrome plating. Is a water-soluble coating agent capable of forming
The surface modifier is a substance that adjusts the wettability of the coating agent with respect to the die.

According to the steel drum can die according to one aspect and another aspect of the present invention, the steel drum can die is further provided with a white rust suppressing film that covers at least a part of the unichrome plating and suppresses white rust generation. .. According to this white rust inhibiting film, the coating of the base resin can reduce the occurrence of white rust on the die. The coating agent for forming the white rust inhibiting film is a composition capable of forming a film by being dried and formed into a film at a temperature lower than that of the thermosetting coating material, that is, a temperature at which unichrome plating is not deteriorated. Therefore, the steel drum can die according to one aspect and another aspect of the present invention is advantageous in terms of cost in that a high-priced material is not used, and the above-mentioned low-temperature dryness film forming property is utilized to prevent contamination of the contents. Regarding the property, the unichrome plating, which has been proven in the past, can be opposed to the contained object, and when the unichrome plating is opposed to the contained object, the conventional non-contaminating property of the contained object can be obtained.
According to the steel drum can die according to still another aspect, since it includes the surface conditioner, the white rust inhibiting film is formed only on at least a partial region of the die flange and the plug by partial coating such as spray coating. be able to.

It is an image figure for demonstrating the structure of the water-soluble coating composition (coating agent) for forming the white rust inhibitory film coat|covered with respect to unichrome plating in the steel drum base of embodiment. FIG. 3 is a cross-sectional view of a die flange and a plug having a white rust suppressing film formed of the coating agent shown in FIG. 1 in the steel drum can die of the embodiment. In the steel drum cap of the embodiment, it is a view showing the screwed state of a cap flange and a plug having a white rust suppressing film formed by the coating agent shown in FIG. 1, and showing exposed surfaces of the cap flange and the plug. .. It is a perspective view of a steel drum can which has a steel drum can base of an embodiment.

A steel drum can base and a steel drum can according to an embodiment of the present invention will be described below with reference to the drawings. In each figure, the same or similar components are designated by the same reference numerals. Further, in order to avoid unnecessary redundancy in the following description and facilitate understanding by those skilled in the art, detailed description of well-known matters and repeated description of substantially the same configuration may be omitted. .. Further, the contents of the following description and the accompanying drawings are not intended to limit the subject matter described in the claims.

Further, in the embodiment described below, as the steel drum can, a tight head type steel drum can conforming to JIS Z 1601 is taken as an example, but it is also applicable to an open head type steel drum can (JIS Z 1600). And steel drums with capacities in excess of 200 liters and up to about 400 liters.

Further, as shown in FIG. 4, in the present specification, a steel drum can base 100 (which may be simply referred to as a “base”) 100 having a rust preventive treatment is an injection port provided in the top plate 11 of the steel drum can 10. Includes both 102 and vent 104. Here, the injection port 102 is an opening portion used for putting in and taking out the stored items in the steel drum 10, and the ventilation port 104 is an opening portion for ventilating to facilitate the input and output of the stored items.

Further, as shown in FIGS. 2 and 3, the steel drum can base 100 of the present embodiment has a base flange 110 and a plug 120, and is attached to the top plate 11 of the steel drum can 10. The base flange 110 has an internal thread 111, and the plug 120 has an external thread 121 that is screwed with the internal thread 111.
The base 100 is attached to the top plate 11 by inserting the base flange 110 into the opening formed in the top plate 11 and caulking it. The plug 120 is screwed and attached to the base flange 110, as shown in FIG. Such a structure of the base 100 itself corresponds to that which has existed in the past, and the mounting method is the same as before.

On the other hand, the die 100 according to the present embodiment is greatly different from the conventional die in that the die 100 has a white rust suppressing film 210 for particularly suppressing the occurrence of white rust. The white rust suppressing film 210 and the die 100 having the white rust suppressing film 210 will be described below.

As shown in FIGS. 2 and 3, the white rust suppressing film 210 is a film that covers the unichrome plating 50 that has already been processed on the die 100. In other words, since white rust is generated in the unichrome plating 50 portion, the unichrome plating 50 is coated with the white rust suppressing film 210 in order to suppress the generation. Such a white rust suppressing film 210 is formed by drying and forming a coating agent described below.
The unichrome plating 50 will be described again with reference to FIG. The unichrome plating 50 is performed by first subjecting the base material of the die 100 to zinc plating 52, and then subjecting the zinc plating 52 to gloss chromate treatment. The film formed by this glossy chromate treatment is the glossy chromate film 54. Therefore, the unichrome plating 50 has the zinc plating 52 and the glossy chromate film 54.

The zinc plating 52 has a thickness of about 5-10 μm as an example, and the glossy chromate film 54 has a thickness of about 0.1 μm as an example. The zinc plating 52 may be zinc alloy plating. The glossy chromate film 54 is a chemical conversion film containing trivalent and hexavalent chromium and is intended to improve the corrosion resistance of the zinc plating 52.

The white rust suppressing film 210 is a film that imparts further corrosion resistance to the unichrome plating 50, and for example, a water-soluble coating composition (hereinafter, referred to as a main component of a chemical manufactured by Nippon Surface Chemical Co., Ltd. "Coating agent") is dried to form a film. Specifically, the coating agent 200 (FIG. 1) corresponding to the above water-soluble coating composition includes a water-soluble resin 202 that can be uniformly dispersed in water and a metal oxide 204 as basic constituent materials. A mixture containing, for example, a surface conditioner 208, a lubricant 206, and other substances depending on the function of adding to the white rust suppressing film 210 obtained from the coating agent 200 or the coating method of the coating agent 200. Is. It should be noted that such a coating agent 200 is an undiluted solution, and water is further added at the time of actual application, and the coating agent 200 is diluted 2-3 times for use.

In this document, “water-soluble” means that the resin 202 occupying a large part in the coating agent 200, the other metal oxide 204, the surface conditioner 208, and the lubricant 206 are also uniformly and easily dispersible in water. In addition, it means that substances contained in other substances can be dissolved or uniformly dispersed in water. Therefore, it can be said that the coating agent 200 is a water-soluble composition as a whole.

FIG. 1 is an image diagram for visually explaining the constituent substances included in the coating agent 200. The coating agent 200 is shown to include both a lubricant 206 and a surface conditioner 208. There is. The white rust inhibiting coating 210 is a coating obtained by drying and coating the coating agent 200 applied to the unichrome plating 50 as described later.

The thickness of the white rust suppressing film 210 is, for example, in the range of about 0.3 μm or more and about 2 μm or less. This film thickness can be changed by the concentration of the coating agent 200, the number of times of coating, and the number of times of baking.

In addition, as described above, the coating agent 200 contains the water-soluble resin 202, and is described in the above-mentioned Patent Document 1 containing a water-insoluble (oil-based or organic solvent-based) epoxy resin or phenol resin as a main component. It is very different from the one. That is, the coating agent 200 is largely different from the epoxy resin in that it can be formed into a film by drying at a low temperature that does not deteriorate the unichrome plating 50 and is water-soluble. Furthermore, the thickness of the white rust suppressing film 210 is different from that described in Patent Document 1 in which 2-8 μm is optimal.

Each composition constituting the coating agent 200 will be described below.
The resin 202 is a main material of the coating agent 200 and is a material for improving the corrosion resistance of the die 100, and an acrylic resin or the like can be used as an example. More specifically, the resin 202 is a polymer represented by the following formula (1), and at least one selected from the group consisting of formula (1) and styrene, vinyl, ethylene, α-olefin, maleic acid, and urethane. At least one selected from the group consisting of at least one of the following:

ここで、Ｒ１はＣｍＨ_{（２ｍ＋１）}、Ｒ２はＣｋＨ_{（２ｋ＋１）}又はＬｉ、Ｋ、Ｎａ、ＮＨ４
であり、ｍ、ｋは０〜３の整数であり、ｎは任意の整数である。

Here, R1 is CmH _(2m+1) , R2 is CkH _(2k+1) or Li, K, Na, NH4.
Where m and k are integers from 0 to 3, and n is an arbitrary integer.

The metal oxide 204 is a material for improving the adhesion of the coating agent 200 to the glossy chromate film 54 and the strength of the white rust suppressing film 210, and includes, for example, silicon oxide, alumina, niobium oxide, and oxidation. Iron, neodymium oxide, lanthanum oxide, zirconium oxide, titanium oxide and the like can be used.

In addition, the resin 202 and the metal oxide 204, which are the basic constituent materials of the coating agent 200, are selected from materials having chemical resistance, and thus have excellent chemical resistance. Therefore, the die 100 coated with the coating agent 200 and having the white rust suppressing film 210 formed thereon can be applied to many objects stored in the steel drum can 10.

The lubricant 206 is a material for adjusting the friction coefficient in order to reduce friction when the base flange 110 and the plug 120 of the base 100 are screwed together, and for example, synthetic wax, natural wax, PTFE fine particles, molybdenum disulfide. , At least one selected from organic molybdenum, and graphite can be used.

In addition, among the coating methods of the coating agent 200 described below, when the method of immersing the entire die 100 in the coating agent 200 is adopted, the white rust suppressing film 210 forms the screws of the die flange 110 and the plug 120. Since the lubricant 206 is also formed on the portion, the addition of the lubricant 206 is particularly effective for improving the sliding of the screwed portion and preventing the generation of metal chips such as plating. However, even in this case, since the coating agent 200 includes the resin 202 as described above, it has a certain degree of lubricity, and the addition of the lubricant 206 is not essential. On the other hand, when the coating agent 200 is applied only to the exposed surface 60 described below, the addition of the lubricant 206 may be unnecessary. In this embodiment, the coating agent 200 does not include the lubricant 206.

The surface modifier 208 is a compound that adjusts so-called wettability such as fluidity and spreadability of the coating agent 200 with respect to the die 100 when the coating agent 200 is applied. For example, an acrylic polymer, polysiloxane, and At least one of fluorine-based surfactants and the like can be used. The surface conditioner 208 needs to be added in order to obtain good coatability when the coating agent 200 is spray-painted on the die 100, particularly when it is applied only to the exposed surface 60 described below. Further, when partial coating is performed, spray coating is often used because of its simplicity. In this case, the surface modifier 208 can be added to adjust the coating agent 200 to have a viscosity and a contact angle within a predetermined range. it can. In addition, as an example of a predetermined range of viscosity, 2-2.5 mPa·s (measurement condition: 60 rpm and 6 rpm, 25° C., B-type viscometer), or 6-7.5 seconds (measurement condition: Iwata cup) [Viscosity cup NK-2], 25° C.), and as an example of the predetermined range of the contact angle, the average value (5 times) is 28-38° (measurement conditions: unichrome plated substrate, static drop method, temperature 24° C., Humidity 30%).
The above-mentioned physical property values such as the viscosity of the coating agent 200 are values in the undiluted solution, and are not values when actually applied.

In the present embodiment, the coating agent 200 includes, as the resin 202, the acrylic polymer represented by the above formula (1) and the copolymer of the formula (1) with vinyl, ethylene, α-olefin, maleic acid, and urethane. Silica is used as the metal oxide 204, an acrylic polymer or a fluorine-based surfactant is used as the surface modifier 208, and a synthetic wax is included when the lubricant 206 is included.

As a method of applying the coating agent 200 to the die 100 having the unichrome plating 50 applied thereto, as an idea, the entire die 100 is dipped in the coating agent 200 and allowed to stand, and then the die 100 is dried with a centrifugal dryer. It is possible to employ a method of performing drying and film formation at a temperature in the range of room temperature to a maximum of 100° C., for example, a temperature in the range of 60° C. to 80° C. while rotating.
As described above, the film thickness of the white rust suppressing film 210 after the coating agent 200 was processed was in the range of about 0.3 μm to 2 μm.

In FIG. 2, a state in which the coating agent 200 is applied to the entire surface and the white rust suppressing film 210 is formed on the entire surface of each of the base flange 110 and the plug 120 on which the unichrome plating 50 is applied by the above-described application method. Is shown.

On the other hand, in FIG. 3, as another example of the method for applying the coating agent 200, the coating agent 200 is applied only to the exposed surface 60 of the die 100 that is exposed to the external environment in a state where the plug 120 is screwed onto the die flange 110. Is applied to form the white rust suppressing film 210. In this case, the exposed surface 60 corresponds to the caulked portion with respect to the top plate 11 in the base flange 110, and corresponds to the inner surface 125a of the recess 125 and the upper end 126 in the plug 120. On the other hand, on the exposed surface 60, the plug 120 occupies a larger area than the caulked portion of the base flange 110. Therefore, the coating agent 200 is applied only to the plug 120 of the exposed surface 60 to form the white rust suppressing film 210. Good. Further, in the mode in which the white rust suppressing film 210 is formed only on the plug 120, the process of applying the plug 120 and the production of the steel drum can can be separated, which is advantageous in the takt time in the production of the steel drum can. The effect is also obtained.
When the plug 120 having the white rust suppressing film 210 thus formed is provided as a single piece, the caulking portion of the base flange 110 may be partially coated with the coating agent 200 separately. Therefore, as a mode of applying the coating agent 200 to the exposed surface 60, it is possible to apply the coating agent 200 to at least one of the base flange 110 and the plug 120 on the exposed surface 60.

2 and 3, the unichrome plating 50 is omitted from the cap flange 110 and the plug 120 for simplification of the illustration, and the white rust suppressing film 210 is exaggeratedly illustrated.

Further, when the coating agent 200 is applied only to the exposed surface 60 as in the embodiment shown in FIG. 3, a method of immersing the entire die 100 in the coating agent 200 cannot be adopted. On the other hand, a brush coating method or a spray coating method is adopted. At this time, in the brush coating or the spray coating, it is difficult to perform drying and film formation while rotating as described above, and it becomes difficult to secure the uniformity of the coating film. Therefore, by adding the surface conditioner 208 as described above, the surface tension of the coating agent 200 can be adjusted to ensure the uniformity of the coating film.

When the coating agent 200 is applied only to the exposed surface 60 or only the plug 120 included in the exposed surface 60, the unichrome plating 50 is exposed in the other regions, and as described above, the glossy chromate film. Since the heat resistance of 54 is poor, it is necessary to take care so that the temperature for drying and forming the coating agent 200 does not exceed 100° C., which is a temperature that does not deteriorate the unichrome plating 50, specifically, the glossy chromate film 54. This is because when the temperature exceeds 100° C., the corrosion resistance of the glossy chromate film 54 decreases. The time for drying and forming a film at this time is until the water content disappears, and is, for example, 10 minutes or less. If it exceeds 10 minutes, the corrosion resistance of the glossy chromate film 54 is also deteriorated.
On the other hand, when the coating agent 200 is applied to the entire surface of the die 100, the unichrome plating 50 is covered with the white rust suppressing film 210, so that it is not necessary to pay attention to the drying and film forming conditions as compared with the case of partial application. ..

The application area of the coating agent 200 on the base 100 can be either of the configurations shown in FIGS. 2 and 3. When the coating agent 200 is applied to the entire surface of the die 100 as shown in FIG. 2, the white rust suppressing film 210 formed by the coating agent 200 in which the contents of the steel drum can 10 are located on the inner side of the can of the die 100. Can be contacted. Therefore, in the case where the elution of the white rust suppressing film 210 into the contained matter is strictly controlled, the effect of being able to completely prevent the elution can be obtained by adopting the configuration of FIG. On the other hand, as described above, the film thickness of the white rust suppressing film 210 is as thin as 2 μm at most, which is very thin, compared to the standard coating film thickness of about 10 μm. Is very small compared to the total area in the can, and the location of the white rust suppressing film 210 is on the back surface of the top plate 11, which is rarely in constant contact with the contents. Is considered to be extremely small. Therefore, in most cases, it is considered that the configuration of FIG. 3 can be used.

According to the die 100 having the white rust suppressing film 210 described above, the following effects can be obtained.
First of all, since the unichrome plating 50 is coated with the white rust suppressing film 210, the corrosion resistance performance for the die 100 can be significantly improved. Therefore, even when water is present, it is possible to significantly reduce the occurrence of white rust on the die 100 as compared with the conventional case. As a result, it is possible to significantly reduce white rust as a foreign matter, which is secondarily mixed into the can as a foreign matter, as compared with the conventional case.
As described in the above-mentioned problem column, white rust generation is a particularly important problem for the steel drum 10 and it is a great news for the steel drum 10 that the effect of suppressing white rust is higher than the conventional one. , Is significant.

Further, such an effect of suppressing the occurrence of white rust can be achieved by the white rust suppressing film 210 which is less expensive than a cost-increasing means such as a stainless steel material or a solid lubricant. This is extremely significant for the steel drum 10 whose overall price is required to be set low as described above. This point can also be said to be a unique effect on the steel drum 10.

The resin 202 included in the coating agent 200 that forms the white rust suppressing film 210 is water-soluble, that is, a resin that can be easily and uniformly dispersed in water as described above, and a normal heat such as an epoxy resin. It is a resin that can be dried and formed into a film at a lower temperature than the resin applied to the curable coating material, that is, at a temperature that does not deteriorate the unichrome plating 50. Therefore, with the unichrome plating 50 exposed, for example, as shown in FIG. 3, only the exposed surface 60 or only the plug 120 included in the exposed surface 60 is coated with the coating agent 200 to form the white rust suppressing film 210. Can be formed. As a result, it is possible to have the same non-contaminating property with respect to the contained items and to effectively suppress the occurrence of white rust on the base 100.
2 and 3, since the white rust suppressing film 210 covers at least a part of the unichrome plating 50, the corrosion resistance of the unichrome plating 50 to the glossy chromate film 54 is also suppressed. be able to.

Furthermore, since the coating agent 200 is water-soluble, local exhaust and explosion-proof equipment in the factory, which is necessary when applying a normal epoxy resin paint containing an organic solvent when applying the coating agent 200. Is unnecessary. Since the local exhaust and explosion-proof equipment imposes a heavy load and burden on the space in the factory and the installation cost, the fact that the local exhaust and explosion-proof equipment is not necessary greatly contributes to the reduction of the load on the equipment.

On the other hand, when the configuration shown in FIG. 2 is adopted, the corrosion resistance of the entire die 100 can be improved as described above. Therefore, when the white rust suppressing film 210 is unlikely to be eluted into the contents in the can, need not be considered, or can be ignored, it is easy to adopt the configuration shown in FIG.

Further, as described above, since the white rust suppressing film 210 has a thin film thickness of at most 2 μm, the amount of the coating agent 200 used can be small and the cost effect can be obtained.

Further, the coating agent 200 may include a metal oxide 204 that improves the adhesion of the unichrome plating 50 to the glossy chromate film 54, and may also include a lubricant 206. Therefore, the adhesion between the white rust suppressing film 210 and the unichrome plating 50 is improved, and when the lubricant 206 is included, the friction when the base flange 110 and the plug 120 of the base 100 are screwed is reduced. .. As a result, it is possible to suppress the occurrence of an event such as peeling of the white rust suppressing film 210 or generation of chips.

According to an experiment conducted by the applicant regarding chips, a plug 100 having a white rust inhibiting coating 210 and a conventional die having no white rust inhibiting coating 210 were opened and closed with a predetermined torque of 40 Nm as an example. When the weight of the chips generated at that time was compared, the result that the die 100 having the white rust suppressing film 210 was 1/4 or less of the case of the conventional die.

Further, by adjusting the content of the lubricant 206, the friction coefficient of the white rust suppressing film 210 can be controlled. Therefore, it is possible to solve the problem of excessive or insufficient tightening of the plug 120 with respect to the base flange 110.

INDUSTRIAL APPLICABILITY The present invention can be applied to a steel drum can, more specifically, to a die on a top plate of the steel drum can.

10... Steel drum, 11... Top plate, 50... Unichrome plating, 60... Exposed surface,
100... Steel drum can base, 110... Base flange, 111... Internal thread,
120...Plug, 121...Male thread,
200... Coating agent, 202... Resin, 204... Metal oxide, 206... Lubricant,
208... Surface conditioner, 210... White rust suppressing film.

Claims (10)

A base attached to a top plate (11) of a steel drum (10), comprising a base flange (110) and a plug (120) screwed to the base flange, and made of unichrome plated steel (50). A drum base (100),
A white rust suppressing film (210) for covering the unichrome plating to suppress the generation of white rust is further provided, and the white rust suppressing film contains a resin (202) and a metal oxide (204) to deteriorate the unichrome plating. A water-soluble coating agent that can form a film at a temperature that does not allow it to dry and form a film.
A steel drum can base, which is characterized by that. A base attached to a top plate (11) of a steel drum (10), comprising a base flange (110) and a plug (120) screwed to the base flange, and made of unichrome plated steel (50). A drum base (100),
A white rust suppressing film (210) that covers the unichrome plating to suppress the generation of white rust is further provided, and the white rust suppressing film includes a resin (202), a metal oxide (204), and a surface conditioner (208). ) And a water-soluble coating agent capable of forming a film at a temperature at which unichrome plating is not deteriorated and dried to form a film,
The surface modifier is a substance that adjusts the wettability of the coating agent with respect to the die,
A steel drum can base, which is characterized by that. The steel drum can base according to claim 2, wherein the metal oxide is silicon oxide, and the surface modifier is an acrylic polymer. 4. The white rust suppressing film is provided only on the exposed surface (60) of the steel drum cap that is exposed to the external environment in a state where the cap flange and the plug are screwed together. The steel drum cap according to any one of the above. The steel drum cap according to claim 4, wherein the white rust suppressing film is provided only on the plug of the exposed surface. The white rust inhibiting film dried and formed into a film at a temperature from room temperature to 100° C. or less with respect to the unichrome plating by the coating agent has a thickness in the range of 0.3 μm to 2 μm. The steel drum cap according to any one of the above. The steel drum cap according to claim 1, wherein the coating agent contains a lubricant (206). A top plate (11) and a cap attached to an opening formed in the top plate, which includes a base flange (110) and a plug (120) screwed to the base flange, and a unichrome-plated steel drum can base ( 100), and a steel drum comprising
The steel drum can further comprises a white rust suppressing film (210) which covers the unichrome plating and suppresses white rust generation.
The white rust inhibiting film contains a resin, a metal oxide, a lubricant (206) and a surface conditioner (208) and is a water-soluble coating that can be dried and formed at a temperature that does not deteriorate unichrome plating. The agent is dried and formed into a film, and the surface modifier is a substance that adjusts the wettability of the coating agent with respect to the die.
A steel drum that is characterized by that. The steel drum according to claim 8, wherein the white rust suppressing film is provided only on an exposed surface (60) of the base exposed to an external environment in a state where the base flange and the plug are screwed together. The steel drum according to claim 9, wherein the white rust suppressing film is provided only on the plug of the exposed surface.

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