JP4826419B2 - Resin-coated metal plate for containers - Google Patents

Description

  The present invention relates to a resin-coated metal plate for containers used in cans and lids for canned foods.

Conventionally, tin free steel (TFS), which is a material for metal cans used in food cans, and metal plates such as aluminum have been coated for the purpose of improving corrosion resistance, durability, weather resistance, and the like. The technique of applying this coating not only has a complicated baking process, but also requires a lot of processing time, and further has a problem of discharging a large amount of solvent.
Therefore, in order to solve these problems, a resin-coated metal plate for containers in which a thermoplastic resin film is laminated on a heated metal plate has been developed in place of a coated steel plate, and is currently industrially focused on beverage can materials. Widely used in

  However, when the resin-coated metal plate is used for food canning, there is a problem that when the contents are taken out from the container, the contents are firmly attached to the inner surface of the container, and the contents are difficult to take out. Since this problem is closely related to the consumer's willingness to purchase, it is a very important problem in securing the consumer's willingness to purchase. Nevertheless, the conventional resin-coated metal plate for containers has very few studies for improving the ease of taking out the contents.

Therefore, the present inventors have conducted intensive studies to ensure the contents take-out property, and a specific wax (carnauba wax) is added to the polyester resin so that it contains a large amount of fat. As for the contents (contents with poor adhesion: a mixture of meat, eggs, carbohydrates, etc.), it was assumed that good characteristics could be secured, and Patent Document 1 was filed.
JP 2001-328204 A

  However, with the technique described in Patent Document 1, it is not possible to ensure good content take-out properties due to the strength of adhesiveness for contents with high protein content, such as meat with low fat. It was. This is presumably because the protein has many polar groups, so it easily forms hydrogen bonds with the resin, and also causes lipid adhesion starting from the protein adhering to the resin surface.

  The present invention was made in order to solve the above-mentioned problems, and for a content having a high protein content, while ensuring excellent takeout properties, it also has various characteristics required for container materials. An object is to provide a resin-coated metal plate.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors paid attention to the surface of the resin layer on the inner surface side of the container after the container-molding of the resin-coated metal plate for containers, and determined the surface free energy of the surface. It has been found that by controlling the falling angle of pure water of less than 25 mN / m and 0.1 ml to be 40 degrees or less, excellent contents takeout property can be obtained.

The present invention has been made based on the above findings, and the gist thereof is as follows.
[1] A resin-coated metal plate for containers having a single-layer or multiple-layer resin layer mainly composed of polyester on both sides,
The surface free energy of the surface of the resin layer that becomes the container inner surface after container molding is less than 20 mN / m, and the falling angle of 0.1 ml of pure water is 40 degrees or less ,
The resin layer that becomes the inner surface of the container after forming the container contains a silicone compound,
A resin-coated metal plate for a container having excellent content takeout characteristics, wherein the ratio of the Si concentration and the O concentration on the outermost surface of the resin layer is 0.5 or more and 2.0 or less .
[2] In the above [1], a 0.1 ml hexadecane falling angle on the surface of the resin layer, which becomes the inner surface of the container after the container is molded, is 20 degrees or less, and the resin for containers having excellent contents removability Coated metal plate.
[3] A resin-coated metal sheet for containers having excellent contents take-out properties, wherein, in [1] or [2] , the silicone compound is polydimethylsiloxane or a polydimethylsiloxane copolymer.
[4] In any one of the above [1] to [3] , the surface free energy on the surface of the resin layer that becomes the outer surface side of the container after forming the container is 25 mN / m or more, and the container is excellent in content take-out property Resin coated metal plate.

  ADVANTAGE OF THE INVENTION According to this invention, the resin-coated metal plate for containers excellent in the content taking-out property is obtained. Moreover, the resin-coated metal plate for containers according to the present invention can provide suitable content take-out properties even for contents having a high protein content such as luncheon meat and tuna.

Hereinafter, the present invention will be described in detail.
First, a metal plate coated with a resin will be described. As the metal plate of the present invention, an aluminum plate or a mild steel plate that is widely used as a material for cans can be used, and in particular, a two-layer film in which the lower layer is made of chromium metal and the upper layer is made of chromium hydroxide is formed. A surface-treated steel plate (so-called TFS) is optimal.
Although there are no particular limitations on the amount of TFS metal chromium layer or chromium hydroxide layer deposited, from the viewpoint of adhesion after processing and corrosion resistance, both are in terms of Cr, the metal chromium layer is 70 to 200 mg / m ² , chromium water The oxide layer is preferably in the range of 10 to 30 mg / m ² .
And in this invention, resin is coat | covered on both surfaces of the said metal plate, and it is set as a resin-coated metal plate. Details of the resin to be coated at this time will be described later.

  Further, the surface free energy on the surface of the resin layer that becomes the inner surface of the container after the resin-coated metal plate is molded into the container is less than 25 mN / m, and the falling angle of 0.1 ml of pure water is 40 degrees or less. This is a feature of the present invention and is the most important requirement in the present invention. In this way, by defining the surface free energy of the resin layer surface on the inner surface side of the container and the falling angle of pure water, it is possible to ensure excellent take-out properties even for contents with a high protein content ratio It becomes.

  By setting the surface free energy on the surface of the resin layer to less than 25 mN / m, the interaction between the contents and the resin layer can be reduced. For this reason, since it works to suppress adsorption of protein and cells derived from the contents, it is considered that the contents adhere to the resin layer. If it is less than 20 mN / m, the interaction with the contents can be further reduced, which is preferable. If it is less than 17 mN / m, it is more preferable.

  However, in order to secure the take-out property for the high-protein content, it is not sufficient to simply reduce the surface free energy, and it is necessary to consider dynamic wettability. Here, the dynamic wettability is a liquid removing ability on the resin surface. As a result of examination, in the present invention, the falling angle of pure water is used as an evaluation of dynamic wettability. Here, the falling angle is an angle at which the droplet starts to slide on the test piece when a 0.1 ml droplet is placed on the plate-like test piece and the plate-like test piece is gradually inclined. By controlling the resin surface so that the drop angle when using pure water as droplets is 40 degrees or less, the adhesive force of the contents is reduced, and the remaining amount after removal can be greatly reduced. It becomes. From the above, the falling angle of 0.1 ml of pure water on the surface of the resin layer on the inner surface side of the container is 40 degrees or less. A falling angle of 35 degrees or less is preferable because the adhesive force of the contents is further reduced. If it is less than 30 degree | times, it is still more suitable.

  In addition, by controlling the resin surface so that the falling angle when hexadecane is used as a droplet is 20 degrees or less, it is possible to reduce the adhesion of the contents to the lipid component (lipophilic component). Become. Therefore, the falling angle of 0.1 ml of hexadecane on the surface of the resin layer that is the inner surface of the container is preferably 20 degrees or less. A falling angle of 15 degrees or less is more preferable because the adhesive force of the lipid component is further reduced. If it is less than 10 degrees, it is more suitable.

  Moreover, it is preferable that the surface free energy and falling angle of the resin layer prescribed | regulated by this invention are maintained after a retort sterilization process. Proteins in the contents are heat-denatured by being subjected to heat treatment during the retort sterilization process. Since the higher-order structure of a heat-denatured protein collapses, the hydrophilic and hydrophobic groups that existed in the molecular chain in the undenatured state change the configuration, and many hydrophilic groups are distributed on the protein surface. Will be. For this reason, the protein after heat denaturation will be in the surface state which is more easily attached to the resin surface which has polyester as a main component. Therefore, the surface of the resin layer containing polyester as a main component needs to maintain the surface free energy and the falling angle even after the retort sterilization treatment.

  A technique for adding a silicone compound to the resin layer is a technique for setting the surface free energy of the resin layer mainly composed of polyester to less than 25 mN / m and the falling angle of 0.1 ml of pure water to 40 degrees or less. Is preferred. Among these, a treatment in which polydimethylsiloxane, a polydimethylsiloxane copolymer, or a modified silicone obtained by reacting an organic group with polydimethylsiloxane is added to a polyester resin is effective. Examples of the polydimethylsiloxane copolymer include a copolymer with polymethylvinylsiloxane and a copolymer with polymethylhexenylsiloxane. Examples of the modified silicone include amino modification, carboxyl modification, and alcohol modification.

  Here, the polydimethylsiloxane preferably has a weight average molecular weight (Mw) of 1000 or more. This is because it is easily fixed on the surface of the resin layer, and the surface free energy and the falling angle can be stably maintained. More preferably, it is 5000 or more, More preferably, it is 10,000 or more.

The addition amount of the silicone compound used in the present invention must be adjusted so that the surface free energy and the falling angle of the resin layer mainly composed of polyester are within the specified range of the present invention. At this time, the ratio (Si concentration / O concentration) of Si concentration (Atomic%) and O concentration (atomic%) on the outermost surface of the resin layer is preferably 0.5 or more and 2.0 or less. If it is less than 0.5, the coverage of the resin layer surface with the silicone compound is insufficient, and it is difficult to stably maintain the surface free energy and the contact angle within the ranges specified in the present invention. On the other hand, if it exceeds 2.0, the contribution to the performance is saturated, a special effect cannot be obtained, and the cost may be increased.
The ratio between the Si concentration and the O concentration on the detailed surface can be experimentally determined by the XPS method (Xray PhotoElectron Spectroscopy). In the present invention, SSX-10 manufactured by Seiko Instruments Inc. is used, Al-Kα rays (hν = 1486.6 eV) are used, and measured values when measured under conditions of a beam diameter of 1000 μm and a photoelectron capture angle = 35 ° are used. .

  The surface free energy on the surface of the resin layer that becomes the outer surface of the container after the resin-coated metal plate is formed into a container is preferably 25 mN / m or more. This is because, as described above, since a product name, a trademark, and the like are usually printed on the outer surface of the container, it is necessary to increase the wettability with respect to ink. As the resin layer having such a surface free energy value, a resin mainly composed of polyester can be used. The resin containing polyester as a main component is a resin containing 50 mass% or more of polyester and exceptionally including polyolefin.

  The configuration of the resin layer used in the present invention may be a single layer or multiple layers. However, one surface of the resin layer is required to take out contents, and the other surface is required to adhere to a steel plate. Therefore, it is preferable to use a multilayer structure because the functions can be shared between the upper layer and the lower layer.

  In the case of a multi-layer structure, it is necessary that the surface free energy of the surface of the upper polyester resin layer in contact with the contents is less than 25 mN / m and the falling angle of pure water is 40 degrees or less.

  In addition, at least the upper polyester resin layer of the polyester resin layer having a multilayer structure preferably has a heat softening point of 130 ° C. or higher as defined in JIS K2425. This is because the retort sterilization treatment for food cans is required to have a heat resistance of more than 120 ° C. because it may take 1 hour or more at a high temperature of 120 ° C. or more. The glass transition point is desirably 30 ° C. or higher. This is because when the resin-coated metal plate is stored and transported, it may be held at a temperature of 30 ° C. or higher for a long time.

Next, the polyester resin layer suitably used in the present invention will be described below.
The composition of the polyester resin layer is represented by polyethylene terephthalate comprising terephthalic acid as the carboxylic acid component and ethylene glycol as the glycol component, but isophthalic acid, phthalic acid, succinic acid, naphthalenedicarboxylic acid, adipine as other carboxylic acid components Examples of the acid component include diethylene glycol, propylene glycol, butanediol, neopentyl glycol, and the like as other glycol components.

The polyester resin preferably has a weight average molecular weight of 5,000 to 40,000, particularly preferably 10,000 to 30,000.
As the acid component, isophthalic acid is preferable because it is transparent, has high tear strength, and is excellent in safety, and is preferably a copolymerized polyethylene terephthalate obtained by copolymerizing isophthalic acid at a ratio of 22 mol% or less. Is particularly preferred. When the isophthalic acid copolymerization ratio exceeds 22 mol, the heat resistance of the resin layer is deteriorated, and the durability to heat treatment such as retort sterilization treatment is applied, so that it is difficult to achieve the object of the present invention. There is.
The thickness of the polyester resin of the present invention is preferably 2 μm or more and 100 μm or less, more preferably 8 μm or more and 50 μm or less, and particularly preferably 10 μm or more and 25 μm or less. Moreover, when it is set as a multilayer structure, it is preferable that the thickness of the polyester resin layer used as an upper layer is the range of 0.5 or more and 5.0 micrometers or less, More preferably, it is the range of 0.5 or more and 1.5 micrometers or less. is there.

  Furthermore, by adding a color pigment to the resin layer containing polyester as a main component defined in the present invention, the underlying metal plate can be concealed and various colors unique to the resin can be imparted. For example, by adding a white pigment, the metallic luster of the base can be concealed and the printed surface can be made clear and a good appearance can be obtained.

  As a pigment to be added, it is necessary to be able to exhibit excellent design properties after being molded into a container. From such a viewpoint, inorganic pigments such as titanium dioxide and organic pigments such as isoindolinone can be used. Since these have strong coloring power and abundant malleability, they are suitable because they can ensure good designability even after being molded into a container. In the case of the resin layer that becomes the outer surface side of the container after the container is formed, it is preferable to use titanium dioxide.

  In the case where the resin layer defined in the present invention has a multilayer structure, the pigment may be added to at least one of the layers, and is preferably added to a resin layer other than the uppermost layer. By containing the pigment, the resin layer becomes slightly brittle, and therefore, when applied to the uppermost layer, the resin may be scraped when it is rubbed against the mold during container molding.

  The amount of pigment added is not particularly specified, but generally, when the content is 30% by mass or more with respect to the resin layer, the concealing property is saturated and economically disadvantageous. , It is desirable to be in the range of less than 30 mass%. In addition, the addition amount of the said pigment is a ratio with respect to the resin layer which added the pigment.

Next, a manufacturing method will be described.
First, the manufacturing method of the resin layer (film) containing the multilayer which coat | covers a metal plate is demonstrated. It does not specifically limit about the manufacturing method of a resin layer (film). For example, it may be a non-oriented resin layer formed by a direct laminate manufacturing method. A resin layer formed by heat-adhesively laminating a biaxially stretched film on a metal plate is preferable because impact resistance and corrosion resistance are improved.
Moreover, as a formation method of a multilayer structure, you may laminate | stack directly on a metal plate by co-extruding a several resin layer with a direct laminate manufacturing method. A method of heat-sealing a polyester film having a multilayer structure on a metal plate may be used.
When adding a silicone compound to a polyester resin, for example, a method of adding a polydimethylsiloxane to a molten polyester resin, kneading with an extrusion molding machine and then melt-extruding to form a resin film on a metal plate, The coating liquid containing is applied during or after the formation of the polyester film to form a polyester resin layer containing a silicone compound as the uppermost layer. For the purposes and applications of the present invention, the latter is preferred. desirable.
Especially, the method of apply | coating at the time of film formation of a biaxially-oriented polyester film or after film formation, and making it heat-dry and forming a coating film is preferable. When applying at the time of film formation, it is preferably performed immediately after drum casting or immediately after longitudinal stretching after casting on the drum. In addition, in the application to the biaxially oriented polyester film, a gravure roll coating method is suitable, and the drying conditions after application of the coating liquid are 80 ° C. to 170 ° C. for 20 to 180 seconds, particularly 80 ° C. to 120 ° C. 60 to 120 seconds are preferred.

  Next, a method for producing a resin-coated metal plate by laminating the resin layer (film) on a metal plate by a heat fusion method will be described. In the present invention, for example, a metal plate is heated at a temperature exceeding the melting point of the film, and a resin film is brought into contact with both surfaces using a pressure-bonding roll (hereinafter referred to as a laminate roll) and heat-sealed (hereinafter referred to as a laminate). ) Can be used.

The laminating conditions are appropriately set so that the resin layer defined in the present invention can be obtained. For example, it is preferable that the temperature at the start of lamination is at least the melting point of the film, and the temperature history received by the film at the time of lamination is the time of contact at a temperature equal to or higher than the melting point of the film in the range of 1 to 20 msec. In order to achieve such lamination conditions, it is necessary to cool during bonding in addition to lamination at high speed. The pressure applied at the time of lamination is not particularly specified, but the surface pressure is preferably 9.8 to 294 N / cm ² (1 to 30 kgf / cm ² ). If this value is too low, even if the temperature reached by the resin interface is equal to or higher than the melting point, the time is short, so the melting is insufficient and it is difficult to obtain sufficient adhesion. In addition, if the pressure is large, there is no problem in the performance of the laminated metal plate, but the force applied to the laminate roll is large and equipment strength is required, resulting in an increase in the size of the apparatus, which is uneconomical.

Examples of the present invention will be described below.
A steel plate having a thickness of 0.18 mm and a width of 977 mm subjected to cold rolling, annealing, and temper rolling was defatted, pickled, and then chrome-plated to produce a chrome-plated steel plate (TFS). Chromium plating was performed by chromium plating in a chromium plating bath containing CrO ₃ , F ⁻ , SO ₄ ²⁻ , intermediate rinsing, and then electrolyzed with a chemical conversion treatment solution containing CrO ₃ and F ⁻ . At this time, electrolysis conditions adjusted to metallic chromium adhering amount and chromium hydroxide deposition amount (current density, the quantity of electricity, etc.), respectively Cr terms was adjusted to ^{120mg / m 2, 15mg / m} 2.

  Next, using the metal band laminating apparatus shown in FIG. 1, the chrome-plated steel sheet 1 obtained above is heated by the metal band heating apparatus 2, and the container is formed on one surface of the chrome-plated steel band 1 by the laminating roll 3. Various resin 4a shown in Table 1 is laminated as the resin resin layer that will be the inner surface of the container later, and various resins 4b shown in Table 2 are laminated on the other surface as the resin layer that becomes the outer surface of the container after container molding (thermal fusion). )did. Thereafter, the metal band cooling device 5 was used for water cooling to produce a resin-coated metal plate.

  The laminating roll 3 was an internal water-cooling type, and cooling water was forcibly circulated during the laminating to perform cooling during film adhesion. Moreover, when laminating the resin film on the metal plate, the time during which the film temperature at the interface in contact with the metal plate was equal to or higher than the melting point of the film was set in the range of 1 to 20 msec.

  Here, the manufacturing method of a film is demonstrated. A polyester resin obtained by polymerizing ethylene glycol as a diol component and terephthalic acid and / or isophthalic acid as a dicarboxylic acid component in the ratios shown in Tables 1 and 2 is dried, melted, extruded, cooled and solidified on a cooling drum, and unstretched film Then, biaxial stretching and heat setting were performed to obtain a biaxially oriented polyester film.

  Subsequently, a resin containing a polyester resin as a main component, the silicone swelled product, and other additives were dissolved in a mixed solvent of toluene and methyl ethyl ketone at a weight ratio shown in Table 1 to prepare a coating solution. This coating liquid was applied and dried with a roll coater on one side of the polyester film that would be the inner surface of the container after molding, and the thickness of the dried resin layer was adjusted. The drying temperature was in the range of 80 to 120 ° C.

The characteristics of the resin-coated metal plate obtained by the above method and the resin layer on the metal plate were measured and evaluated by the following methods (1) to (6), respectively.
(1) Surface free energy The contact angle when a liquid is dropped on the resin surface that becomes the inner surface of the container after container molding of the resin-coated metal plate and the resin surface that becomes the outer surface of the container after container molding is θ, If the dispersion force component of the surface free energy is γs ^d , the polar force component is γs ^h , the liquid surface free energy is γl, the dispersion force component is γl ^d , and the polar force component γl ^h , these are the following relationships: Satisfied.

γl (1 + cosθ) / 2 * (γl ^h ) ^1/2
= (Γs ^d ) ^1/2 * (γl ^d ) ^1/2 / (γl ^h ) ^1/2 + (γs ^h ) ^1/2
Therefore, the surface free energy using a known ^(γl, γl h, γl ^d is known) five liquid (water, glycerol, formamide, et thien glycol, diethylene glycol), and the contact angle meter (manufactured by Kyowa Interface Science Co., CA-X type) was used to determine the static contact angle with respect to the resin layer surface before and after retort sterilization (130 ° C., 90 minutes) (humidity: 55 to 65%, temperature 20 ° C.).

The formula to the 5 solution each for measuring the contact angle θ and each of the liquid Ganmaeru of, Ganmaeru ^h, by substituting the value of Ganmaeru ^d, the least squares method fitting, seeking ^{γs d, γs h, γs (} = (γs ^d + γs ^h ) was calculated.
Table 3 shows the surface free energy values of the five liquids used in the measurement.

(2) Falling angle of pure water and hexadecane The falling angle measurement unit (SA-X type manufactured by Kyowa Interface Science Co., Ltd.), which is an option of the contact angle meter, was used. A 0.1 ml pure water droplet and a 0.1 ml hexadecane droplet are dropped on the resin surface on the inner surface of the container, and the unit is gradually inclined. The angle of the unit when the liquid droplet began to roll was measured and used as the falling angle. The smaller the drop angle value, the easier the droplets roll on the surface of the resin and the less likely the droplets remain on the surface.

(3) Si concentration (Atomic%) / O concentration (Atomic%)
The ratio (Si concentration / O concentration) of the Si concentration (Atomic%) and the O concentration (Atomic%) on the outermost surface by XPS method was determined with respect to the resin surface on the inner surface side of the resin-coated metal plate after forming the container. Here, SSX-10 manufactured by Seiko Instruments Inc. was used, measurement was performed using Al—Kα rays (hν = 1486.6 eV), a beam diameter of 1000 μm, and a photoelectron capture angle = 35 °.

(4) Content take-out property Using a drawing machine, a laminated metal plate was cup-formed at a drawing step with a blank diameter: 100 mm and a drawing ratio (diameter before molding / diameter after molding): 1.88. Subsequently, low-fat salted meat (protein ratio in solid content: 50% or more) was filled in the cup, and the lid was tightened, followed by retort sterilization (130 ° C., 90 minutes). Then, when the lid was removed and the contents were taken out with the cup upside down, the degree of ease of taking out the contents was evaluated by observing the degree of the contents remaining inside the cup.
(About the score)
○: The contents can be taken out only by turning the cup upside down (without shaking by hand), and when the inner surface of the cup after removal is observed with the naked eye, there is almost no deposit.
Δ: The contents remain inside the cup just by turning the cup upside down, but the contents can be taken out by vibrating the cup up and down (such as shaking the cup by hand). When the inner surface of the cup after removal is observed with the naked eye, it is almost impossible to confirm the deposits.
X: It is difficult to take out the contents only by vibrating the cup up and down (such as shaking the cup by hand). When the speed of vibrating up and down is extremely increased, or when the contents are forcibly removed using a spoon or other instrument and the inside of the cup is observed with the naked eye, the deposit can be clearly confirmed.

(5) Formability After applying wax on the coated metal plate, a disk having a diameter of 179 mm was punched out to obtain a shallow drawn can with a drawing ratio of 1.80. Next, the drawn can was redrawn at a drawing ratio of 2.20. Then, after performing doming forming according to a conventional method, trimming was performed, and then neck-in-flange processing was performed to form a deep drawn can. Focusing on the neck-in portion of the deep-drawn can thus obtained, the degree of film damage was visually observed.
(About the score)
○: No damage to the film after molding Δ: Moldable but partially damaged film ×: Can not be broken and cannot be molded (6) Printability Resin coated metal sheet A printing ink (printing ink CCST39 manufactured by Toyo Ink Co., Ltd.) was applied to the resin surface on the outer surface side of the container after the container was formed and dried to adjust the coating thickness to 1.5 μm.
Then, Nichiban Co., Ltd. cellotape (registered trademark) is brought into close contact with the painted surface and peeled off at once. A ten-sheet test was conducted to examine the number of sheets peeled off by ink.
○: 0 sheets Δ: 1-3 sheets ×: results obtained from 4 or more sheets are shown in Table 4.

  From Table 4, the invention examples within the scope of the present invention are excellent in the contents take-out property and other characteristics are also good. On the other hand, the comparative example which remove | deviates from the range of this invention is inferior to the content taking-out property, and is inferior also in a moldability and printability depending on the comparative example.

  The resin-coated metal plate of the present invention is suitable for container applications and packaging applications that require excellent contents takeout properties. And it can use as a raw material for containers which perform drawing processing etc., especially a raw material for food can containers.

It is a figure which shows the principal part of the laminating apparatus of a metal plate. Example 1

Explanation of symbols

1 Metal plate (chrome plated steel plate)
2 Metal Band Heating Device 3 Laminate Roll 4a, 4b Film 5 Metal Band Cooling Device

Claims (4)

A resin-coated metal plate for containers having a single-layer or multiple-layer resin layer mainly composed of polyester on both sides,
The surface free energy of the surface of the resin layer that becomes the container inner surface after container molding is less than 20 mN / m, and the falling angle of 0.1 ml of pure water is 40 degrees or less ,
The resin layer that becomes the inner surface of the container after forming the container contains a silicone compound,
A resin-coated metal plate for a container having excellent content takeout characteristics, wherein the ratio of the Si concentration and the O concentration on the outermost surface of the resin layer is 0.5 or more and 2.0 or less .   2. The resin-coated metal sheet for containers having excellent contents removability according to claim 1, wherein a falling angle of 0.1 ml of hexadecane on the surface of the resin layer, which becomes the inner surface of the container after forming the container, is 20 degrees or less. . 3. The resin-coated metal sheet for containers according to claim 1 or 2, wherein the silicone compound is polydimethylsiloxane or a polydimethylsiloxane copolymer. 4. The resin-coated metal plate for a container having excellent content removability according to any one of claims 1 to 3 , wherein the surface free energy on the surface of the resin layer that becomes the outer surface of the container after molding is 25 mN / m or more. .

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