JP5585328B2 - Metal container and manufacturing method thereof - Google Patents

Description

  The present invention relates to a metal container in which a plurality of base coats formed of paints having different colors are applied to the outer surface of a body portion, and a method for manufacturing the same.

  A metal container such as a metal can generally employs a technique of providing a base coat and printing on the base coat when printing is performed on the outer surface of the body portion. That is, it is for enhancing the decorativeness of printing by hiding the surface of the base metal with the base coat.

  The base coat as described above is applied to the entire outer surface of the metal can using a painting roller (applicator roller). Conventionally, the base coat is a single type, for example, two or more types of different colors. The method of providing a base coat was hardly adopted. This is because when two or more types of base coats are provided, variations in the application position of the painting roller occur, resulting in unevenness at the boundary between base coats of different colors.

However, recently, the positioning accuracy of the painting roller has been improved. For this reason, a method of providing a plurality of base coats and printing on backgrounds having different colors has been proposed (see, for example, Patent Document 1).
In the case of providing a plurality of base coats, for example, a printed image is sharpened with a white base coat, and at the same time a metallic feeling is imparted by providing a silver base coat, thereby further improving the decorating property, Product value can be increased.

Japanese Patent No. 421801

  By the way, in the metal container in which a plurality of base coats are provided on the outer surface of the body part, there is a problem that the outer surface flaws are likely to occur, and improvement thereof is demanded.

  Accordingly, an object of the present invention is to provide a metal container in which generation of wrinkles on the outer surface of the body part is effectively prevented and a method for manufacturing the same in a metal container in which a base coat of a plurality of colors is provided on the outer surface of the body part. It is in.

  According to the present invention, a plurality of base coats formed of paints having different colors are applied to the outer surface of the trunk portion, and each base coat extends in a stripe shape over the entire circumference of the outer surface of the barrel portion and is adjacent to each other. The matching base coats extend without overlapping each other, and a metal container is provided in which a band-shaped gap is formed between the two base coats.

In the metal container of the present invention,
(1) The plurality of base coats are formed of white paint and silver paint,
(2) the gap is shielded by the printing layer;
(3) The base coat is not formed on the upper end portion of the trunk portion;
(4) A polyester film layer is provided on the outer surface of the trunk, and the base coat is applied on the polyester film layer.
(5) The polyester film layer is a white pigment-containing polyester film layer,
Is preferred.

  According to the present invention, in the method of manufacturing a metal container in which a plurality of base coats formed of paints having different colors are applied to the outer surface of the body part, the outer surface of the body part of the metal container is formed using the plurality of painting rollers. A metal container characterized in that a plurality of base coats extending in a stripe shape over the entire circumference are sequentially formed so that adjacent base coats do not overlap each other and a band-like gap exists between them. A manufacturing method is provided.

In the production method of the present invention,
(6) After forming the base coat, shielding the gap by printing,
(7) Forming the base coat by contacting the coating roller with the outer surface of the body part avoiding the upper end of the body part of the metal container;
(8) The metal container is provided with a polyester film layer on the outer surface of the trunk,
(9) The polyester film layer is a white pigment-containing polyester film layer,
(10) forming the plurality of base coats using a white paint and a silver paint;
Such means can be preferably employed.

  According to the metal container of the present invention, generation of outer surface flaws is effectively prevented. That is, a band-like gap is formed at the boundary between adjacent base coats, and no protrusions are formed due to the overlap of the base coats. As a result, contact between the outer surfaces of the body portions during the transportation of the metal container is effectively suppressed. It is considered that the suppression of such contact has prevented the occurrence of external flaws.

  In the metal container of the present invention, preferably, a plurality of base coats are formed with white paint or silver paint, so that the printed image formed on the white ground with the white paint becomes clear and the silver color with the silver paint A metallic feeling can be given to the groundwork and the decorating property of a printed image can be improved.

  In the metal container of the present invention, it is most preferable that the gap existing between the adjacent base coats is shielded by the printed layer. It is possible to effectively avoid concealment and deterioration in decorating properties due to the presence of gaps.

  Further, in the metal container of the present invention, it is preferable that the base coat is not formed on the upper end portion of the barrel portion, and by adopting such a configuration, the wear of the coating roller due to contact with the upper end of the barrel portion is achieved. And avoiding scratches.

  Further, in the metal container of the present invention, it is preferable that a polyester film layer is provided on the outer surface of the body portion, and the base coat is provided on the polyester film layer. Post-processing of a metal container in which roughening of the surface of the metal container formed by molding such as drawing-stretch ironing draw processing or drawing-ironing processing is prevented and the base coat is not formed on the upper end portion of the body portion Can be done smoothly.

  Furthermore, in the metal container of the present invention, it is preferable that the polyester film layer is a white pigment-containing polyester film layer, and by such a configuration, the surface of the base metal is more effectively concealed. , Sharpness and decoration of printed images are improved.

  According to the method for manufacturing a metal container of the present invention, the protrusion due to the overlap between the base coats is not formed, the occurrence of outer surface flaws due to the contact between the outer surface of the body part during the transportation of the metal container is effectively prevented, The metal container which improved the decorating property of a printed image can be obtained easily.

It is a figure which shows the typical form of the metal container of this invention. It is sectional drawing of the boundary part of 2 types of basecoats, (a) shows the basecoat boundary part in a conventionally well-known metal container, (b) shows the basecoat boundary part in the metal container of this invention. It is a figure which shows the other form of the metal container of this invention. It is a figure which shows the application | coating process of the basecoat in the process of manufacturing the metal container of FIG. It is a figure which shows the application | coating process of the basecoat in the process of manufacturing the metal container of FIG.

  In the metal container and the manufacturing method thereof according to the present invention, a plurality of base coats extending in a stripe shape are formed over the entire circumference of the outer surface of the body portion by the paints having different colors, and the adjacent base coats do not overlap each other among the plurality of base coats. It has a remarkable feature in that it is provided so that a gap is formed between them.

That is, as a result of observing wrinkles generated on the outer surface of a metal container in which a plurality of base coats are formed on the outer surface of the body portion by paints of different colors, such wrinkles are mostly borders between adjacent base coats. It was observed that wrinkles were particularly noticeable when they occurred in the part and when the base coat was an ultraviolet curable paint. This base coat is a coating provided to conceal the surface of the metal material underlying the metal container. Using a low-viscosity coating, it is applied repeatedly by a painting roller, and after application, it is dried and cured. It is formed.
Therefore, the thickness of the base coat is considerably thicker than the printed layer formed by printing.Therefore, when a plurality of base coats are provided on the outer surface of the body without gaps, the boundary between adjacent base coats overlaps with each other. As a result, the linear protrusion is formed thick. When such a thick protrusion is formed on the outer surface of the body, the protrusion frequently contacts the outer surface of the body of another metal container when the metal container is transported. It seems that wrinkles occur. In particular, when the base coat is cured by ultraviolet irradiation, curing at the protrusions where the base coats overlap each other is insufficient, resulting in low film strength and insufficient adhesion, resulting in significant wrinkling. It is thought to become.

  FIG. 1 is a diagram showing a typical form of a metal container according to the present invention, and two types of base coats 3a and 3b having different colors are provided on the outer surface of the body of the metal container indicated by 1 as a whole. Each of these base coats 3a and 3b extends in a stripe shape over the entire circumference of the outer surface of the trunk portion. Further, these base coats 3a and 3b extend without overlapping each other, and there is no gap between them. 5 is formed.

  That is, by forming two types of base coats 3a and 3b having different color tones on the outer surface of the body portion of the metal container 1, the surface of the base metal is concealed when a printed image (not shown) is formed thereon. Therefore, the decorativeness of the printed image is enhanced, for example, the printed image becomes clearer.

By the way, the base coats 3a and 3b are provided to conceal the surface of the base metal, and are applied using a coating roller described later, and the thickness thereof is generally about 1 to 10 μm.
Normally, when the base coats 3a and 3b are provided in this way, the base coats 3a and 3b are formed without gaps in order to completely conceal the surface of the base metal on the outer surface of the body portion. Therefore, as shown in FIG. 2 (a), an overlap portion A is formed at the boundary between the base coats 3a and 3b for reasons such as variations in the application position of the application roller. The coating becomes thick. That is, a printing layer 7 is generally provided on the base coats 3a and 3b, and a transparent varnish layer 8 is further provided thereon, but a linear protrusion B is formed corresponding to the overlap portion A. End up. For this reason, when the metal container 1 is transported, the protruding portion B comes into contact with the outer surface of the body portion of the other metal container 1, and as a result, the outer surface flaws frequently occur at the boundary portion. Become. In particular, when the base coats 3a and 3b are cured by ultraviolet irradiation, the protrusion B tends to cause poor curing, the strength at the protrusion B is low, and the adhesion to the outer surface of the body portion is also reduced. For this reason, the protruding portion B (overlap portion A) itself is easily peeled off, and as a result, the occurrence of outer surface wrinkles becomes more remarkable.
However, in the present invention, as shown in FIG. 2 (b), the gap 5 (the portion where the base coat is not applied) is formed in a band shape between the base coats 3a and 3b, and the base coats 3a and 3b , Not overlapping at all. That is, the overlap portion A of the base coats 3a and 3b is not formed at all, and therefore, the protruding portion B derived from the overlap portion A is not formed. Occurrence can be reliably prevented.

  In the present invention, the width t of the gap 5 as described above (see FIG. 1) is such that the overlapping of the base coats 3a and 3b is reliably prevented according to the positioning accuracy of the coating roller described later. However, if the width t is increased more than necessary, the effect of improving the decorating properties of the base coats 3a and 3b will be reduced. Accordingly, the width t is generally set to a size of about 0.5 to 5.0 mm, particularly about 1.0 to 3.0 mm.

  In addition, referring to the cross-sectional view of FIG. 2B, in order to avoid the appearance deterioration of the metal container 1 due to the gap 5 as described above, the printed layer 7a is formed on the base coats 3a and 3b, and the gap 5 It is preferable to shield (that is, the surface of the base metal) with the printing layer 7b. In this case, the print layer 7b and the base coats 3a and 3b are overlapped. However, the print layers 7a and 7b are formed by printing ink transfer using a predetermined printing plate, and the thickness thereof is For example, it is about 1 to 4 μm, and this printing ink enters the gap 5 (concave portion) between the base coats 3a and 3b, and further, the outer surface varnish (finish varnish) is applied to form the varnish layer 8, so that the base coat 3a , 3b, the irregularities generated in the gaps are alleviated and no external flaws are generated.

  The color tone of the printed layer 7b formed for shielding the gap 5 is set to an appropriate color according to the form of the printed image formed on the base coats 3a and 3b, but generally dark. It is preferable to conceal the surface of the base metal in the gap 5 with a color tone.

Furthermore, in the present invention, as shown in FIG. 1, it is preferable that the base coat is not applied to the upper end portion 9 of the body portion of the metal container 1. That is, if a base coat is applied to the upper end portion 9, there is a risk that the coating roller may come into contact with the sharp end portion and wear or be damaged, but by not providing a base coat on this portion. Such inconvenience can be avoided reliably.
The width d of the upper end portion 9 (the distance between the upper end of the upper base coat 3a and the upper end of the trunk portion in FIG. 1) is usually about 1.5 to 3.5 mm.

  In the present invention described above, the number, size, and the like of the base coats having different color tones can be appropriately set according to the form of the printed image formed on the base coat. For example, in the example of FIG. 1, two base coats 3a and 3b having different color tones are formed. However, as shown in FIG. 3, three base coats 3a, 3b, and 3c may be formed. In this case, all of the three base coats 3a, 3b, 3c may be formed of paints having different color tones, or the base coats 3a, 3c are made of the same color with the same paint, and the intermediate base coat 3b is made of another one. Depending on the paint, the color tone can be different. In any case, the color tone of each base coat can be set so that the color tone of adjacent base coats is different.

  Of course, also in the embodiment of FIG. 3, a gap 5 is formed at the boundary between adjacent base coats, specifically, between the base coats 3a and 3b and between the base coats 3b and 3c, exactly as in the embodiment of FIG. Furthermore, it is preferable that a printing layer (not shown) is provided so as to shield the gap 5 and that the base coat is not provided on the upper end portion 9 of the body portion.

  The base coat described above is, for example, a thermosetting, ultraviolet curable, or electron beam curable resin component such as a polyester resin, an acrylic resin, an epoxy resin, a polyurethane resin, a curing agent component such as an isocyanate or a melamine resin, a radical, etc. A polymerization initiator and various pigments having a predetermined color tone are dispersed or dissolved in a predetermined organic solvent, applied with a paint adjusted to an appropriate viscosity, dried, and further heated according to the type of the resin component. It is formed by curing by ultraviolet irradiation, electron beam irradiation or the like.

In the present invention, a white paint for forming a white base coat and a silver paint for forming a metallic silver base coat are most preferably used.
That is, the white paint contains a white pigment such as titanium oxide or zinc oxide as the pigment, and the silver paint contains a metal powder pigment such as aluminum powder or lamellar mica particles as the pigment. Pearl pigments obtained by coating the surface of titanium dioxide with iron oxide or the like, or glass flakes or glass flake pigments coated with metal or the like, and those using aluminum powder are particularly suitable. .

For example, in the example of FIG. 1, the base coat 3a is formed of a white paint to form a white base coat, and the base coat 3b is formed of a silver paint to have a metallic silver color. Of course, conversely, the upper base coat 3a can be formed of silver paint, and the lower base coat 3b can be formed of white paint.
In the example of FIG. 3, it is preferable that the upper and lower base coats 3a and 3c are formed of silver paint, and the intermediate base coat 3b is formed of white paint, and vice versa. is there.
In particular, in the prior art, as the number of base coats increases, protrusions are formed at the boundary portions of the base coat, and the frequency of wrinkles tends to increase. However, in the present invention, the number of base coats is 3 as shown in FIG. Even when the number of base coats is increased, or when the number of base coats is further increased, generation of wrinkles can be reliably prevented by forming the gap 5 at the boundary between base coats having different colors.

The metal container to which the base coat as described above is applied is not particularly limited, and various metal plates, for example, surface-treated steel plates such as aluminum plates, aluminum alloy plates, tin-free steel, tin plates, chrome-plated steel plates, aluminum-plated steel plates. , Nickel-plated steel sheets, tin-nickel-plated steel sheets, and various alloy-plated steel sheets, etc. Although it may be a metal can, it is optimal to apply the present invention to a seamless can in which a polyester film layer is formed on the inner and outer surfaces.
That is, the inner surface of the seamless can which has been made ultrathin by drawing-stretching, drawing-stretching ironing, or drawing-ironing processing is formed from the viewpoint of corrosion resistance and protection of contents such as beverages, while the outer surface has moldability. A polyester film layer is laminated in order to improve surface roughness and prevent roughening of the surface of the metal material during molding.
Further, by providing a polyester film layer on the outer surface of the body portion and providing the base coat on the polyester film layer, it is possible to smoothly perform post-processing of the metal container in which the base coat is not formed on the upper end portion of the body portion. .
Furthermore, the polyester film layer on the outer surface of the seamless can is a polyester film layer containing a white pigment composed of colorant particles such as titanium oxide, which has been known in the past, so that the surface of the base metal of the seamless can is more effective. It is possible to improve the sharpness and decoration of the printed image by the base coat described above. Such a white pigment is usually preferably blended in an amount of 3 to 40 parts by weight per 100 parts by weight of the polyester resin.

In the metal container of the present invention described above, the base coat is formed by sequentially applying base coats of different colors using an application roller, drying, and curing.
For example, in order to form the base coats 3a and 3b on the metal container 1 of the embodiment shown in FIG. 1, as shown in FIG. 4, an application roller 11 for applying a paint (for example, white paint) for forming the base coat 3a. And the coating roller 13 for applying a coating (for example, silver coating) for forming the base coat 3b, the coatings may be sequentially applied to the outer surface of the body portion of the metal container 1.

That is, the coating roller 11 is applied in contact with the outer surface of the body of the metal container 1 while rotating while the coating material supply roller 15 is pressed against the coating roller 11 to supply the coating material, thereby forming an uncured base coat 3a (see FIG. 4 (a)). At this time, the application roller 11 is applied to the upper end portion 9 of the metal container 1 so that the coating roller 11 comes into contact with the edge of the upper end portion 9 of the metal portion 1 of the sharp metal container 1 to prevent wear and damage. The position of the application roller 11 is adjusted so that the surfaces do not contact each other.
Next, in the same manner, the coating roller 13 is applied in contact with the outer surface of the body of the metal container 1 while rotating while the coating material supply roller 15 is pressed against the coating roller 13 to supply the coating material, and the uncured base coat 3b is applied. It forms (refer FIG.4 (b)). At this time, it is necessary to bring the application roller 13 into contact with the outer surface of the body portion of the metal container 1 so that a predetermined gap 5 is formed between the previously formed uncured base coat 3a.

  The base coat 3a and the base coat 3b are sequentially applied as described above, and then cured according to the type of the binder resin component in the paint, such as heating, ultraviolet irradiation, or electron beam irradiation. 3a and 3b can be formed.

Further, in order to form the base coats 3a to 3c on the metal container 1 having the mode shown in FIG. 3, for example, as shown in FIG. 5, an application roller for applying a paint (eg, white paint) for forming the base coat 3b. 21 and the application roller 23 for applying a paint (for example, silver paint) for forming the base coats 3a and 3c, each paint is applied from the paint supply roller 15 to the application roller 21, While being supplied to 23, it is sequentially applied to the outer surface of the body portion of the metal container 1. In this case, the application roller 23 has two paint supply surfaces, and can apply the paint for the base coats 3a and 3c (both are the same paint) at the same time (FIGS. 5A and 5B). )reference).
In application using the application roller 23, position adjustment is performed so that the application surface does not contact the upper end portion 9 of the body portion of the metal container 1, and the application layer of the base coat 3b applied in advance The application is performed so that the predetermined gap 5 is formed between the two in the same manner as in the example of FIG. 4 described above.

  The base coat 3b and the base coat 3a and 3c are sequentially applied, dried, and then cured by heating, ultraviolet irradiation, electron beam irradiation, or the like to form the base coats 3a to 3c. it can.

In the present invention, after the base coat is formed at a predetermined position on the outer surface of the body portion of the metal container 1, printing is performed on the gaps 5 between the base coats having different color tones to form the print layer 7b. A predetermined printed image (7a) is formed on the base coat. The printed image (7a) does not need to cover the entire base coat, and may be a partial print in which a part of the base coat can be seen as it is. Such printing is performed using oil-based or water-based inks in which pigments or dyes of respective colors are dissolved or dispersed in a predetermined solvent together with a binder resin component and a dispersant. The binder resin component may be basically the same as the paint for forming the base coat.
As a printing method, screen printing, flexographic printing, gravure printing using a gravure roller, offset printing, ink jet printing using an ink jet printer, or the like can be used.

After printing is performed as described above, a varnish layer 8 is formed by applying a finish varnish for drying and curing for glossing and printing image protection, if necessary (see FIG. 2B). The upper end portion 9 of the body portion is subjected to post-processing such as necking and flanging to form a can body for a two-piece can. After the contents are filled, a lid is attached and the product is put on the market.
As the finishing varnish, a conventionally known transparent thermosetting resin is used. For example, a thermosetting polyester resin, an acrylic resin, an epoxy resin or the like is included as a thermosetting resin component, and further, as a curing agent component. An amino resin such as a phenol resin or a melamine resin or an isocyanate resin is contained, and these resin components are appropriately dissolved in an organic solvent.

  In the metal container of the present invention described above, since the base coat of a plurality of colors is applied to the outer surface of the trunk portion, the decorative surface is extremely high, and at the same time, the outer surface that frequently occurs in this type of metal container conventionally. The generation of soot is effectively prevented.

1: Metal container 3a, 3b, 3c: Base coat 5: Gap 7: Print layer 9: Upper end

Claims (12)

  A plurality of base coats formed of paints of different colors are applied to the outer surface of the trunk part, and each base coat extends in a stripe shape around the entire outer circumference of the trunk part, and adjacent base coats overlap each other. The metal container is characterized by extending without being formed and having a band-shaped gap formed therebetween.   The metal container according to claim 1, wherein the plurality of base coats are formed of a white paint and a silver paint.   The metal container according to claim 1, wherein the gap is shielded by a printing layer.   The metal container according to claim 1, wherein the base coat is not formed on an upper end portion of the trunk portion.   The metal container according to any one of claims 1 to 4, wherein a polyester film layer is provided on an outer surface of the body portion, and the base coat is applied on the polyester film layer.   The metal container according to claim 5, wherein the polyester film layer is a white pigment-containing polyester film layer.   In a method for manufacturing a metal container in which a plurality of base coats formed of paints of different colors are applied to the outer surface of the body part, a plurality of coating rollers are used to extend in a stripe shape over the entire circumference of the outer surface of the body part of the metal container. A method of manufacturing a metal container, comprising: sequentially forming a plurality of base coats so that adjacent base coats do not overlap each other and a band-like gap exists between the base coats.   The method for manufacturing a metal container according to claim 7, wherein after forming the base coat, the gap is shielded by printing.   9. The method for manufacturing a metal container according to claim 7, wherein the base coat is formed by contacting the coating roller with an outer surface of the body part while avoiding an upper end part of the body part of the metal container.   The said metal container is a manufacturing method of the metal container in any one of Claim 7 thru | or 9 by which the polyester film layer is provided in the trunk | drum outer surface.   The method for producing a metal container according to claim 10, wherein the polyester film layer is a white pigment-containing polyester film layer.   The manufacturing method according to any one of claims 7 to 11, wherein the plurality of base coats are formed using a white paint and a silver paint.