JP2003200521A - Film stuck metal can - Google Patents

Abstract

(57) [Problem] To provide a metal can that can improve the design of decoration applied to the outer surface of a can body by a novel visual effect. SOLUTION: A thermoplastic resin film 2 is adhered to an outer surface of a can body 1 via a resin adhesive 4, and a resin adhesive layer 4 is formed.
A decorative layer which is printed with a pearl ink made of a resin composition containing a pearl pigment 10 and a printing ink made of a resin composition containing a color pigment between a thermoplastic resin film 2 and a thermoplastic resin film 2 and represented on a can body In the film-attached metal can formed with 30, the pearl pigment 10 has a configuration in which the flakes 11 are coated with the titanium oxide layer 12 and the titanium oxide layer 12 is coated with the iron oxide layer 13, and a printing layer or printing using pearl ink is performed. A film-sticking metal can, characterized in that a portion develops a different color depending on the polarization of the pearl pigment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal can whose outer surface is decorated by printing with a pearl pigment, and more particularly, to a pearl pigment composed of flakes coated in two layers.

[0002]

2. Description of the Related Art Generally, metal cans (containers) made of aluminum or steel are roughly classified into three types, three-piece cans, two-piece cans, and bottle-type cans, depending on their shapes. This three-piece can is called a three-piece can because it consists of three parts: a bottom lid, a can body joined by welding or bonding, and a canopy. A two-piece can is called a two-piece can because it has a structure in which a canopy is attached to a can body with an integrated can bottom and two members, a can body and a canopy, are constituent members. It is also called a seamless can because it is seamless. Further, the bottle-shaped can consists of a side seamless can body having a threaded portion formed at one open end of the can body, a cap and a bottom lid screwed to the threaded portion, and the overall shape is old. It is called a bottle-shaped can because it is similar to the glass bottle of.

The outer surface of each of these metal cans is not limited to simply displaying the name and type of the content, but also a variety of decorations are provided according to the content accommodated inside the metal can. We are trying to improve the distinctiveness of our products and contribute to the sale of our products.

In particular, when the content is a favorite beverage such as beer, coffee, or soft drink, since the beverage itself has a strong character as an image product, the appearance of the metal can is important as well as its naming.・ It is a point.

That is, it is desired that the image presented by the product is not spoiled and that the product image is adapted and further the product image is improved. Further, in addition to this, diversification of demands for products due to trends in consumption and changes in needs, there is a demand for metal cans with a more beautiful appearance.

Therefore, in recent years, in order to meet such demands and to secure superiority in terms of design, a special visual effect is added to this decoration to add new added value, This effect makes it stand out from the competition.

In order to meet such demands, as an alternative to a can directly printed on the outer surface of a metal can, a preprinted thermoplastic resin film such as polyester is attached to the outer surface of the metal can. Various cans have been proposed.

As a method for producing this printing film, in addition to offset printing, it is possible to select gravure printing or flexographic printing method, and these printing methods are more decorative than the conventional dry offset printing method. Is highly effective, good print quality is obtained, and since continuous thermoplastic resin film is used instead of the can body, high-speed printing can be expected. It has advantages that cannot be obtained.

It is also known that a pearl pigment is added to the printing ink to give a special color tone to the decoration. It is said that this pearl pigment can impart a pearly luster or an iris color to the decoration by a special optical effect, so that it can give a high-class feeling or a decorative effect such as a unique volume feeling. .

That is, a natural pearl is formed by alternately stacking thin films of protein and calcium carbonate from the central core, and the incident light is regularly reflected at the boundary between these two layers arranged in parallel. , Pearl luster is obtained. Therefore, similarly, by arranging mica (mica) having a low refractive index and titanium oxide having a high refractive index in a layered manner,
I try to get a pearly luster. That is, the pearl pigment has a structure in which the outer surface of the particulate mica is coated with titanium oxide, and as shown in FIG. 13, from the light reflected from the surface of the titanium oxide layer and from the interface between the titanium oxide layer and the mica layer. The pearly luster is obtained by the interference with the reflected light.

For this reason, in a solid color in which the inside is made of the same substance and has the same color tone, even if the angle at which the portion colored with the solid color is viewed is changed, the lightness and hue thereof do not change. However, the pearl color of the above pearl pigment changes the lightness and hue depending on the angle at which the pearl-colored part is viewed, resulting in a deep color tone and a high-class feeling. Can have

Further, a polyester film is adhered to the metal surface on the outer surface side of the can body of the metal can body through a resin adhesive layer, and an iris type mica powder is provided between the film and the adhesive layer. Japanese Patent Laid-Open No. 8-198272 discloses and proposes a metal can body having a printed layer formed by gravure printing a resin composition containing a pearl pigment. Therefore, according to this configuration,
The printed layer looks like a pearlescent or iris-like special color,
Moreover, when the viewing angle is changed, the printed layer appears to have a color tone different from the original color tone due to the polarization of the pearl pigment, so that part is emphasized and an excellent visual impression is given.

[0013]

However, in the metal can using the above pearl pigment for printing, further,
In order to meet the demands of various products such as deformed cans, embossed cans, complicated characters, designs, etc., metal cans having new decorative effects more than conventional ones are required.

That is, in the decoration consisting of a picture or embossed on the outer surface of the metal can, a design of the embossed can, or the like, it is possible to secure superiority in terms of design and to use a specific character color such as green character or blue character. , It is required to expand the range of design choices by making red letters transparent.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a metal can in which the design of the decoration provided on the outer surface of the can can be improved by a new visual effect. is there.

[0016]

In order to achieve the above-mentioned object, the invention of claim 1 is such that a thermoplastic resin film is adhered to the outer surface of a can body through a resin adhesive, A pearl ink made of a resin composition containing a pearl pigment and a printing ink made of a resin composition containing a color pigment are printed between the adhesive system adhesive layer and the thermoplastic resin film and displayed on the can body. In the film-attached metal can having a decorative layer formed thereon, the pearl pigment is composed of flakes coated with a titanium oxide layer and the titanium oxide layer coated with an iron oxide layer. It is characterized in that the portion develops different colors depending on the polarized light of the pearl pigment.

According to the first aspect of the present invention, the flakes of the pearl pigment are coated with the titanium oxide layer and further with the iron oxide layer so as to be coated in two layers. The pearl pigment is coated with the resin composition. By printing inked pearl ink and printing ink to form a decorative layer, a complicated and complex color tone appears on the outer surface of the metal can. Then, since it seems that different colors are mixed with the pearl color, a new visual effect can be obtained and unexpectedness can be secured.

That is, in a conventional metal can in which a pearl pigment is used for printing, the pearl pigment is covered in a single layer so that the outer surface of the can looks like a whitish pearl color when viewed from the front, but it is viewed obliquely. However, in the metal can using the pearl pigment of the present invention for printing, due to the polarization of the pearl pigment,
When viewed directly from the outer surface of the can, it looks pearly green, blue or red, and when viewed obliquely, it is polarized and looks pearly brown, plum or orange.

This is because there is no difference in the length of the optical path of the reflected light reflected from each coating layer formed on the flakes when viewed directly facing the surface of the printed layer or the printed portion made of the pearl pigment. While the interference light due to both reflected lights looks strong, when viewed obliquely with respect to the printed portion, there is a difference in the optical path length of the above reflected light, so the interference light due to both reflected lights weakens. This is because the absorbed light looks strong.

The invention of claim 2 is characterized in that the pearl pigment is blended in a proportion of 20 to 25% by weight with respect to the resin composition.

According to the invention of claim 2, in addition to obtaining the same effect as that of the invention of claim 1, it is possible to secure a sufficient pearly luster and prevent the color tone from becoming muddy. can do.

That is, when a pearl pigment less than the above range is blended, the amount of the pigment dispersed is small, so that the intensity of reflection with respect to the incident light is lowered and a sufficient pearly luster is not exhibited. When the pearl pigment is blended beyond the above range, the pigments aggregate with each other and uniform appearance cannot be ensured, and reflected light affects each other to give a cloudy color tone. Since the pearl pigment is blended in the resin composition in the ratio within the above range, such a situation can be avoided in advance.

According to a third aspect of the present invention, a printed layer or a printed portion formed by the pearl ink and a can body side of the printed layer or the printed portion formed by the printing ink,
It is characterized in that a base printing layer or a base printing portion is formed of the pearl ink or a printing ink having a reflectance lower than that of the printing ink.

According to the invention of claim 3, in addition to obtaining the same effect as that of the invention of claim 1 or 2, the coloring of the decorative layer can be sufficiently ensured, and the pearl pigment is contained. In addition to the effect of the decoration in which the printing layer or the printing portion and the printing layer or the printing portion containing the coloring pigment are combined, the effect of performing the underprinting with the pearl ink or the printing ink having a lower reflectance than the printing ink is obtained. It becomes possible to add.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the present invention will be described below with reference to the drawings. 1 and 4 to 11 are enlarged cross-sectional views showing an outer surface portion of a metal can on which a film having a decorative layer according to this specific example is attached.

That is, the can body 1 used in the present invention is
It is made of metal, and the metal plate as its material is aluminum plate, tin-free steel, stainless steel,
Whether the surface of surface-treated steel plate and metal plate such as tin plate, chrome-plated steel plate, aluminum-plated steel plate, nickel-plated steel plate, turn-plated steel plate, and other various alloy-plated steel plates is coated with a thermosetting or UV-curing paint, Or
A resin-coated metal plate coated with a thermoplastic resin can be used.

The can body 1 includes a can bottom such as a squeezed can (including a can subjected to a drawing process and a stretch process), a squeezed and squeezed can (hereinafter abbreviated as DI can), an impact can, and a can body. It is possible to use a bottomed can body in which and are integrally formed, that is, a two-piece can. It may also be a commonly known three-piece can or bottle-shaped can. In addition, DI
A can is a metal can whose main body is a can body that is formed by drawing (forming) a metal plate and then ironing it.
The body and the bottom have a seamless structure.

That is, the can body of a DI can, which is a two-piece can to which a printed film is adhered, is prepared by using a surface-treated steel plate such as a tin-plated steel plate, a zinc-plated steel plate, or a nickel-plated steel plate as a raw material. It is manufactured by carrying out the manufacturing steps shown in a) to (i).

That is, in the cup forming step (a) of this manufacturing step, first, a cup is formed by drawing from a blank obtained by cutting the above steel plate into a circle. That is,
While pressing a steel plate punched into a disk shape with a wrinkle pressing device, it is formed into a cup shape with a bottom by a tool that combines a punch and a die. Next, in the body molding step (b), DI (Drawing & Ir) is added to the cup.
oning) processing is performed. That is, the side wall of the drawn cup is thinly stretched by drawing and ironing (including pressing of the bottom portion by the forming punch during these processes) to form a deep drawn cup.
Further, in the trimming step (c), the open end is cut off and trimmed to have a predetermined can height dimension.
Then, in the degreasing / chemical conversion treatment step (d), a treatment liquid (hereinafter, referred to as treatment liquid including industrial water, chemical liquid, ion-exchanged water) is sprayed on the inner and outer surfaces of the can to perform surface treatment, and The lubricant attached during the forming / ironing process is removed, and an appropriate surface chemical conversion treatment such as zirconium chemical conversion treatment for corrosion prevention is performed on the inner and outer surfaces of the can body. Next, it is dried in a heating drying oven, and the first
In the protective coating step (e), the protective coating is formed by applying the curable coating on the outer surface side of the can within a predetermined range on both sides along the boundary line between the body and the bottom. After the drying, in the film attaching step (f), the printed resin film is attached to the outer surface of the body. Further, in the second protective coating step (g), coating is applied to the portion where the bottom of the can contacts the ground, and in the third protective coating step (h), coating is spray-applied to the inner surface of the can and the outer surface of the bottom, and heating is performed. To be dried. Then, at the final stage of the manufacturing process, neck-flange processing (j) consisting of neck-in processing and flanging processing is performed to reduce the diameter near the upper end of the cylindrical body as a neck and A flange portion is formed on the upper end of the portion, and a can body of a DI can to which a film is attached is manufactured.

A printed film is attached 3
A welded can body (glass can) for a piece can is manufactured by performing the manufacturing process shown in FIG. 3 using the above steel sheet as a raw material.

That is, in the film attaching step (a),
Unwind the steel plate wound on the drum and feed it in a certain direction,
This strip-shaped steel plate is preheated in advance. As a heating method for preheating the steel sheet, a radiant heating method such as a hot air heating method or infrared heating can be used, but an electric heating method or a high frequency induction heating method is preferable because of the ease of temperature control. Is heated to a temperature range of 100 to 250 ° C. Then, at each position apart from the upper surface and the lower surface of this steel plate, the strip-shaped film wound on the reels is run in the same direction while being unwound, and corresponds to the non-laminated portion before each sticking roll. The part is cut in the longitudinal direction of the film to be removed, and then the side of the adhesive layer applied to the film is directed toward the steel plate, and heat bonding is performed while applying pressure with a bonding roll. As a result, on both upper and lower surfaces of the steel sheet, for example, 2
A film having a plurality of strips such as four strips is continuously heat-bonded along the longitudinal direction of the steel sheet with a predetermined interval such as ˜6 mm. Then, in the first shearing step (b), the steel sheet to which the plurality of strips of film are adhered is cut into sheet sheets each having a length corresponding to a plurality of cans in the longitudinal direction. Further, in the second shearing step (c), a rectangular blank (d) having a size corresponding to one can is cut out from the sheet plate. Then, in the forming step (e), the blank is rolled into a cylindrical shape by the welding can body forming device. Then, in the welding step (f), the circumferentially overlapped end edge portions are welded and joined to form a can body portion. Next, a repair coating (not shown) for protecting the non-laminated portion of the welded portion of the can body is applied to the can body formed in a cylindrical shape, and further, in order to dry the coated paint, Heat drying is performed. That is, in the heating and drying step (MCH step), the repair coating layer formed on the non-laminated portion of the welded portion of the can body is dried by heating the can body to a heating temperature of 150 to 230 degrees. At the same time, at the cutting end located on the inner surface side of the can among the cutting ends generated by the cutting process in the above-mentioned step, peeling of the thermoplastic film, which is the protective coating, occurs. The peeling portion of such a thermoplastic film is removed by pulling along with the curing shrinkage of the curable adhesive.
The film is shrunk by 0% or more so that the peeled portion of the film does not spread further. Next, in the neck processing step (g), one opening end side of the can body is neck processed,
In the flanging (h), flanging is performed. Then, in the double winding step (i), the canopy is wound around this opening end portion to manufacture a cylindrical can body portion having one end opened. After that, the contents are filled from the other opening end, and the ground lid is attached to the opening end by double winding to seal the welding can. Then, the welding can is subjected to a retort treatment in which the temperature is maintained at 125 ° C. for 30 minutes, for example, and the final product is obtained.

Further, the film 2 attached to the outer surface side of the can of the steel plate to be the can 1 is a polyester film (hereinafter, referred to as
It is abbreviated as PET film) and has excellent strength and transparency.

In this PET film 2, 75 to 100% of the repeating ester units are composed of ethylene terephthalate units. Ester units other than ethylene terephthalate units include phthalic acid, isophthalic acid, succinic acid,
Examples thereof include ester units such as adipic acid.

Further, the PET film 2 having a high melting point of about 260 ° C. can be obtained by appropriately selecting the alcohol component and the acid component, which is also preferable because sufficient heat resistance can be secured.

The resin forming the thermoplastic resin film laminated as a protective coating on one surface of the metal plate (the surface which becomes the inner surface of the can) is a resin containing no bisphenol A and has a certain resistance. The resin is not particularly limited as long as it is a resin having processability, heat resistance, water resistance, and gas permeation resistance.

For example, a polyester-based resin, a polyolefin-based resin, a polyamide-based resin, or a resin film made of a mixture of two or more kinds of these can be used, but the resin film having heat resistance and protection of the contents can be used. From the viewpoint, the polyester film is most suitable.

Further, in this embodiment, polyethylene film, polypropylene film and the like can be used in addition to the PET film 2. Furthermore, a transparent polymer resin body selected from polypropylene resin, polycarbonate resin, polystyrene resin, vinyl chloride resin, polyvinylidene chloride copolymer, or the like, or
A thermoreversible resin film made of a composite of the above resins may be used, and the thickness of the thermoreversible resin film is appropriately determined according to the selected material.

The surface of the PET film 2 on which the adhesive layer is formed is preferably subjected to surface oxidation treatment in advance by corona discharge or the like. By such surface treatment, the adhesive strength of the adhesive agent is improved. The bonding strength between the film and the adhesive layer can be increased.

Then, as shown in FIG. 1 again, characters and letters are formed on one surface of the PET film 2 by the first printing layer 3a, which is a resin composition containing a pearl pigment, and a coloring pigment contained in the resin component. The decorative layer 30 including the second printed layer 3b on which the design is printed and the adhesive layer 4 including the thermosetting resin-based or electron beam-curable resin-based adhesive are provided, and the opposite surface is provided. Is provided with a transparent cured overcoat layer 5 formed of a thermosetting resin system or an electron beam curing resin.

The first printed layer 3a has a resin composition of urethane resin or vinyl chloride resin, and the resin composition is about 2
It is formed by a pearl ink in which two layers of 0 to 25% by weight of mica are dispersed.

The second printed layer 3b is formed of a printing ink containing a pigment in a urethane resin or vinyl chloride resin. This first print layer 3
a is a multi-colored and laminated by printing a printing ink containing a pigment of each color for each color so that a pattern composed of a predetermined display and a design image is formed on the outer surface of the can. I have to.

The adhesive layer 4 is formed using a thermosetting resin-based or electron beam-curable resin-based adhesive.

That is, as the thermosetting resin adhesive, a resin obtained by mixing an epoxy resin having a number average molecular weight of 5000 to 20000 and an acid anhydride curing agent in a weight ratio of 70/30 to 99/1, Alternatively, a resin in which a polyester resin and an aminoplast resin are mixed in a weight ratio of 70/30 to 90/10 is used. Therefore, in this case, the PET film 2 is heat-bonded to the steel plate forming the can body 1 through the thermosetting resin-based adhesive layer by heating at high temperature for a short time to form a steel plate. Excellent adhesive strength can be obtained between.

The electron beam curable resin-based adhesive is a resin composition in which 2 to 30 parts by weight of a polyester oligomer having an unsaturated double bond is mixed with 100 parts by weight of a polyester resin, and a stress relaxation agent is added to the resin composition. 0.5 to 250 PHR
(Parts by weight with respect to 100 parts by weight of resin)

The resin component of the adhesive layer 4 is generally added with silica, titanium oxide, etc.
It is used as a base color for ensuring a desired color development by a and 3b.

That is, the printing layer 3 containing the pearl pigment.
The visibility of the pearly luster due to a is affected by the hue of the portion of the printing layer 3b that serves as the printing layer and the hue of the portion that serves as the base of the printing layer 3b. This is because the reflected light from the print layer 3a and the print layer 3b and the print layer 3a and the print layer 3
This is because the reflected light that has once passed through b and is reflected by the base is seen as being mixed.

If the color of the base is white or light, the amount of light reflected from the base increases, so that the pearl pigment contained in the printing layer 3a is reflected by the light reflected from the base. The amount of incident light will be increased. Therefore, the effect of the pearl luster due to the polarization of the pearl pigment is enhanced by the increased reflected light from the underlayer. That is, in addition to the light directly incident from the outside, a large amount of the reflected light from the above-mentioned base is incident on the printing layer 3a, so that the pearl luster color appears even more strongly.
As a result, the reflected light from the print layer 3b that displays characters and designs formed by the color pigment is not reflected by the print layer 3 described above.
Since it is mixed with the light having a pearly luster due to the pearl pigment of a, the visibility of the hue in which these are fused is enhanced.

Therefore, depending on the overall design,
In order to enhance the hue of the print layer 3a, that is, the visibility of the pearly luster color, it is necessary that the base be colored in white or a light color with high reflectance. Further, when it is desired to obtain a hue in which the pearly luster color and the color formed by another colored ink are fused, the above-mentioned printing layer 3b is colored with a dark colored pigment having a low reflectance.

A colorless adhesive may be used as the adhesive layer 4, and in this case as well, it is possible to obtain a characteristic color development by the printing layer 3a containing at least the pearl pigment.

As described above, it is possible to form an adhesive layer that also serves as a colored coat layer by blending a coloring pigment with the adhesive. That is, a white colored layer (usually a white coat) may be required under the printed layer of ink to secure the color development of the printed layer, but if an adhesive layer that also serves as a colored layer is used, The step of forming the colored layer is unnecessary, and one step can be omitted from the manufacturing process.

Further, on the side of the can body 1 of the printing layers 3a and 3b, a pearl ink of the printing layer 3a or a printing ink having a lower reflectance than the printing ink of the printing layer 3b is separately used by various printing techniques. By providing an underprinting layer formed by printing by printing, a hue in which the color developed by the printing layer 3a or the printing layer 3b is fused is obtained, and the underprinting layer provides a more luxurious decoration. It is possible to obtain the effect of. Further, since the effect of the underprinting is added to the effect of the decoration in which the print layer 3a and the print layer 3b are combined, a new synergistic effect is obtained in the decoration and the range of choice of the decoration is widened. As a result, it is possible to further secure the designability according to the request of the product.

That is, in the above-mentioned base printing layer, when a printing layer formed by printing ink by various dot printing is provided, for example, a pearl ink portion is formed in a pattern reflecting this dot printing. Coloring will appear due to the glossy colored ink portion.

In addition to this, the base printing layer may be formed by combining not a single ink but a plurality of inks having different lightness and saturation, and a decorative effect by a more complicated color combination. Can be obtained.

Further, the first printing layer 3a and the second printing layer 3
Even if the content of the can body 1 is a food such as a drink, the inconveniences described below can be solved by the fact that b is composed of urethane resin or vinyl chloride resin as the main vehicle component. Since it is possible to secure good decorativeness, it can be suitably used.

That is, when the content of the can body 1 is a food such as a drink, a heat sterilization process (this is, for example, a retort sterilization process) is performed after the can body 1 is filled with the content. When an electron beam curable adhesive is used for the can body 1, it is irradiated with an electron beam to cure and fix the adhesive, or exposed to sunlight at the time of transportation as a product after completion. As a result, the print layer is discolored or faded, which causes a problem that the decoration such as the design formed by the print layer becomes unclear. Examples of the ink having low heat resistance include inks using nitrified cotton (nitrocellulose) or polyamide resin as a base resin which is the main component of the vehicle.

On the other hand, in this example, the urethane resin or the vinyl chloride resin is used as the vehicle component of the first printing layer 3a and the second printing layer 3b. Even when exposed to light, discoloration and fading of the first printing layer 3a and the second printing layer 3b can be prevented, a clear image is maintained by the printing layer, and good decorativeness can be secured.

The first printing layer 3a and the second printing layer 3b may be arranged in reverse, and a resin composition containing a coloring pigment between the PET film 2 and the first printing layer 3a. A layer of material may be arranged, and further the can body 1
Depending on the overall design of the resin composition, the layer of the resin composition containing the pearl pigment or the layer of the resin composition containing the color pigment may be partially formed, and further, these layers may be combined. The structure may be combined, and the structure can be appropriately selected according to the design required by the product housed in the can body 1.

That is, for example, as an example in which the first printing layer 3a and the second printing layer 3b are arranged in reverse, the example shown in FIG. 4 can be cited. In this example, the adhesive layer 4 and the first printing layer 3 containing the pearl pigment are directed outward from the outer surface of the can body 1, that is, from the lower side to the upper side in the figure.
a, the second printing layer 3 formed by using a low-density ink
0a, the PET film 2 and the cured overcoat layer 5 are provided, and as described above, the first printing layer 3a contains a pearl pigment whose interference color is green, blue or red, and Since the printing layer 3b is formed by using a green, blue or red ink having a low density, the interference color of the first printing layer 3a affects the second printing layer 3b when the outer surface of the can is directly faced. Green, blue or red looks transparent and has a pearly color tone.

Further, the PET film 2 and the first printing layer 3a
As an example in which a layer made of a resin composition containing a color pigment is additionally formed between and, the example shown in FIG. In this example, from the outer surface of the can body 1 to the outer side, an adhesive layer 4, a printing layer 30b formed using a dark printing ink having a low reflectance and a pearl pigment are sequentially contained. 1 printing layer 3a, a second printing layer 30a formed by using a thin ink, a PET film 2, and a cured overcoat layer 5 are provided. As described above, the printing layer 30b has a reflectance of The first printing layer 3a is formed by using a dark dark blue or black ink having a low density, and the first printing layer 3a contains a pearl pigment whose interference color is green, blue or red, and the second printing layer 30a has a high density. Since it is formed by using a light green, blue, or red ink, the pearl tone of the first printing layer 3a has less reflection of the lower printing layer 30b when the outer surface of the can is directly faced, and thus the brightness is reduced. I gave a suppressed solid feeling, and further, Green or blue or red by looking through the second printing layer 30a is visible color tone having a deep.

Furthermore, an example in which a layer of a resin composition containing a pearl pigment or a layer of a resin composition containing a color pigment is partially formed, or a combination of these examples is as shown in FIG. As shown in FIG. 6, the printed portion 3A formed by the pearl ink and the printed portion 30B formed by the dense printing ink having a low reflectance are provided in the same layer, and both 3A and 30B are provided. As described above, the print layer partially formed of the pearl ink has a low reflectance and a dark black color with a low density around the pearl ink. Alternatively, by using a dark blue color, the printed layer formed by the pearl ink gives a solid feeling with suppressed brightness, and further looks like it is raised, or as shown in FIG. The layer 3a is formed in a predetermined range, and a printed portion 31B formed of a printing ink having a low reflectance and a high density is provided below the printed layer, and the interference color is green or blue as described above. Alternatively, a printed portion 3 of a dark navy blue or black ink having a low reflectance is formed under the printed layer 3a containing a red pearl pigment.
Since 1B is partially provided, the coloring by the printing layer 3a has a heavy feeling with suppressed brightness, and it is used as a decoration with a high-class feeling, or as shown in FIG. The print layer 3a is formed in the range
Printed portion 31 formed by printing ink with a low density
As described above, the printed portion 31A is provided with a portion having two layers of printing and a portion having only one layer of the adhesive layer 4 as described above. Therefore, the lower layer is 2 when facing the outer surface of the can.
The part that is a layer obtains transparency and a pearly hue, and the part where the lower layer is one layer is close to the original hue, so when a printing layer containing a pearl pigment is used for a character trademark, a logo, etc. Is emphasized, and if it is used for the outline of a characteristic pattern or trademark, the pattern or trademark inside the outline will appear to be raised,
As shown in FIG. 9, a print layer 3a made of pearl ink is formed in a predetermined range, a print portion 31A made of print ink having a low density is embedded in the print layer 3a, and the print portion 31A is printed. In a direction along the printing surface, a printing portion 31B, which is partially arranged in a direction along the surface and is spaced apart from each other, and which is formed by a printing ink having a high density with a low reflectance, is formed under the printing layer 3a of the pearl ink. The print layer 3a is formed of pearl ink as shown in FIG. 10, or the print layer 3a is formed by embedding a print portion 31A formed of print ink of low density in the print layer 3a. And the print portions 31A are partially arranged at intervals in the direction along the print surface, and the print layer 3a is a lower layer of the pearl ink print layer 3a. A printed layer 30b which is formed by deep printing inks low reflectance density configuration as or provided,
As shown in FIG. 11, a print layer 3a made of pearl ink is formed in a predetermined range, a print portion 31A made of print ink having a low density is embedded in the print layer 3a, and the print portion 31A is printed. In the direction along the printing surface, a printing portion 31B formed by a printing ink 3 having a low density and a low reflectance is disposed under the printing layer 3a of the pearl ink and is partially arranged at intervals in the direction along the surface. An example can be given in which the parts are arranged so as to be spaced apart from each other. Therefore, according to these configurations, the printed portion formed by the pearl ink constitutes a part of the image formed by the printing of the printing ink, and as shown in FIG. 9, FIG. 10, and FIG. , For example, the print layers 30b and 31B are formed by using dark navy blue or black ink having a low reflectance,
The printed layer 3a contains a pearl pigment whose interference color is green, blue, or red, and when the printed portion 31A is formed using a light green, blue, or red ink, the printed layer 3a faces the outer surface of the can directly. Looking at it, the printing layers 30b and 31B
The colors of the two colors are fused with each other to give a deep color tone of green, blue or red.

Further, in FIG. 10, by using the printing layer 30b partially, a finer pattern can be dealt with.

Further, in FIG. 11, two layers of the printing layer 31A and the adhesive layer 4 are partially included, and the printing layer 31A, the printing layer 3a containing the pearl pigment, the printing layer 31B, and the adhesive layer 4 are partially formed.
Since it is a layer, when the printing layer containing the pearl pigment is used for a character trademark, a logo, etc., that part is emphasized, and when it is used for the outline of a characteristic pattern or trademark, the pattern or trademark inside the outline appears. looks like.

The cured overcoat layer 5 is formed by using a thermosetting or electron beam curing type resin. That is, examples of the thermosetting resin forming the cured overcoat layer 5 include those made of an epoxy resin and an aminoplast resin to which a phosphoric acid catalyst is added. Further, as the electron beam curable resin, epoxy acrylate resin,
Polyester acrylate resin, polyurethane acrylate resin, polyether acrylate resin, polybutadiene-based acrylate resin, etc. are mentioned, including those having a relatively high molecular weight from resinous to low monomeric and exhibiting a polymerization reaction by radiation. I wish I had. The electron beam curable resins can be used alone or as a mixture of two or more kinds.

Therefore, by providing the cured overcoat layer 5 on the outermost surface of the can body 1, the PET film 2 is not exposed to the outer surface, and the sliding property of the outer surface of the can body 1 by the PET film 2 is lowered. Since this can be prevented, the transportability of the can body 1 in the subsequent can manufacturing process and can manufacturing process can be ensured, and the efficiency of can manufacturing and can manufacturing can be maintained.

The cured overcoat layer 5 is made of PET.
In the can body 1 in which the protective coating layer is formed by the film 2, it is preferable that silicon or wax is added in order to improve the scratch resistance of the PET film 2 and the slip property of the surface of the can body 1. .

A can body 1 to which a PET film 2 is attached
When an electron beam-curable overcoat is applied to the can body surface of No. 1 to form a cured overcoat layer 5 and an electron beam-curable adhesive is used for the adhesive layer 4, Since it is possible to accelerate the curing of the adhesive at the same time as curing the overcoat paint by irradiation, it is possible to omit the solidification step of the adhesive and solidify the adhesive together in the irradiation step of the electron beam, The number of steps required for manufacturing can be reduced.

Further, when the overcoat layer 5 is an electron beam curable resin, it is not necessary to heat it to cure the overcoat layer 5, so that the thermoplastic resin film is prevented from being deformed due to heat shrinkage. A good appearance of the can body 1 can be secured.

Then, the first containing the pearl pigment of this example
By arranging the second print layer 3b on which a predetermined display and design pattern is formed under the print layer 3a, a special visual effect can be added as a decoration applied to the outer surface of the can body 1. I am trying.

That is, the pearl pigment has conventionally used powder particles of the inner portion of pearl foil or shell, but in the present invention, the outer surface of fine flakes (flake) is a metal oxide or a mixture of metal oxides. As shown in FIG. 12, the pearl pigment 10 of this example further has a two-layer coating layer composed of a titanium oxide layer 12 and an iron oxide layer 13 on the outer side of the flakes 11. The one that is formed is used.

Examples of such fine flakes 11 include aluminum flakes, mica (mica), glass flakes, and synthetic ceramics.

The amount of the pearl pigment 10 to be mixed with the coating resin is preferably adjusted to the range of 0.1 to 30 parts by weight with respect to 100 parts by weight of the vehicle component (solid content). In this example, About 20 to 25% by weight of the pearl pigment 10 is mixed in the ink resin to ensure a sufficient pearly luster and prevent the color tone from becoming muddy.

That is, the amount of the pearl pigment 10 blended is 0.
If it is less than 1% by weight, the amount of dispersed pigment is small,
The intensity of reflection with respect to the incident light is lowered, and the pearly luster is not sufficiently expressed, which causes a problem. On the other hand, when the content of the pearl pigment 10 is 30% by weight or more, the pigments are aggregated with each other and uniform appearance cannot be ensured, and reflected light affects each other to give a cloudy color tone. Inconvenience occurs. Therefore, by blending about 20 to 25% by weight of pigment into the ink, these disadvantages are eliminated.

The individual particle diameter of the pearl pigment 10 composed of the two-layer coated flakes 11 is 5 μm.
While occupying the range of m to 48 μm, its thickness is
It occupies a range of 5 μm to 20 μm, and is formed to have an average particle width of 25 μm.

The individual particle diameters of the flakes 11 on which the single-layer titanium oxide layer contained in the conventional pearl pigment is formed occupy, for example, 5 μm to 25 μm, and the thickness thereof is 5 μm to 15 μm. It occupies the range, and the average particle size is formed to be 15 μm.

Further, the average particle diameter of the flakes 11 coated with two layers in this example is set to 17 μm so that a sufficient glittering feeling and a good appearance by printing can be secured.

That is, when the average particle diameter of the pearl pigment 10 is less than 10 μm, the particles are difficult to be oriented in a certain direction in the ink, so that the intensity of reflection with respect to incident light becomes small, and a sufficient glittering feeling is not expressed. Inconvenience occurs. On the other hand, when the average particle diameter of the pearl pigment 10 exceeds 30 μm, the ink remains as foreign matter in the gravure mesh (recess) of the gravure roll to which the ink is transferred during gravure printing on the film, so that pinholes caused by plate clogging occur. A defect such as (non-printed portion) occurs, and the appearance cannot be ensured by gravure printing. Therefore, these disadvantages are avoided by setting the average particle diameter of the pearl pigment 10 to 17 μm.

In the pearl pigment 10, the surface of the flakes 11 serving as the central core is covered with the titanium oxide layer 12, and the surface of the titanium oxide layer 12 is further covered with the iron oxide layer 1.
It is configured to be covered with 3.

That is, the layer thickness of the flake 11 itself of this example is about 7 to 13 μm, the layer thickness of the titanium oxide layer 12 is about 7 to 13 μm, and the layer thickness of the iron oxide layer 13 is about 7 to 13 μm. The thickness is about 2 to 8 μm.

The pearl pigment 10 having the above structure is made into an ink with a binder of urethane resin or vinyl chloride.

Further, although a urethane resin type or vinyl chloride type is used as a binder (resin portion in the ink) for making the pearl pigment 10 into an ink, the cohesive force of the ink is insufficient as it is, Block isocyanate as a cross-linking agent
Nate) is added. That is, by adding the blocked isocyanate, the crosslinkability of the ink is replenished and the cohesive force of the ink is secured.

Further, since this isocyanate has a high chemical reactivity, if it is added to the ink in advance, it may gel before printing is carried out, and the print quality may deteriorate. . Therefore, when the isocyanate is added to the ink in advance, the reaction part of the added isocyanate is blocked. That is, the reactive group of the isocyanate prepolymer is blocked so that it reacts only when heated at high temperature.

For example, in the case where the manufacturing process of the can body 1 includes a heat treatment of 120 ° by a gravure oven and a heat treatment of 220 ° by a heat drying process after can barrel welding, first, In the former heating at 120 ° C., it takes several tens of minutes to complete the reaction of the isocyanate, so that only a part of the whole ink reacts, whereas in the latter heating at 220 ° C. The reaction will be completed in a few seconds.

Therefore, in consideration of such heating temperature as well, MEK oxime (methyl ethyl ketoxime) is selected as the blocking agent and added to the ink.

As the isocyanate (NCO), a general hexamethylene diisocyanate (Hex
Amethylene diisocyanate) is used.

The flakes 11 thus coated in two layers
According to the ink printing containing the pearl pigment 10 consisting of
Since the length of the optical path of the reflected light is different when looking directly at the printed surface and when looking obliquely to the surface, the color traveling phenomenon that causes different colors to appear is displayed. You can

That is, the light incident on the printing surface of the pearl pigment 10 is not reflected by the iron oxide layer 13 which is the uppermost layer of the pearl pigment 10, and further continues to be incident on the lower layer of the pearl pigment 10. become.

Therefore, as shown in FIG. 12, color development is obtained by the interference between the reflected light reflected by the titanium oxide layer 12 inside the pearl pigment 10 and the reflected light reflected by the surface of the flakes 11.

Therefore, when viewed from the front, FIG.
Since there is no difference in the length of the optical path between the above-mentioned two reflected lights indicated by the arrow on the left side of 2, the interference color looks strong. On the other hand, when viewed obliquely, the absorption colors look strong because the lengths of the optical paths of the two reflected lights indicated by the arrows on the right side in FIG. 12 are different.

As a result, when the surface which is decorated by the ink printing containing the pearl pigment 10 as described above is directly viewed, the interference color looks strong, while when viewed obliquely. Has a strong absorption color.

In particular, when the angle directly facing the printing surface is 0 degree, there is a tendency to polarize at a boundary of around 45 degrees, so that a visual effect that gives a completely different impression depending on the viewing angle can be obtained.

Note that looking directly at the printing surface means looking straight at the object, that is, looking from a direction orthogonal to the flat printing surface. In the present example, this printing surface is viewed. Is a curved surface, that is, since the printing surface is located on the side surface of the can body 1 formed in a cylindrical shape, strictly speaking, it is not possible to directly see the printing surface. However, depending on the size of the can body 1, if it is limited to a minute area on the side surface of the can body 1, it can be considered that this minute area is sufficiently flat. Can Therefore, when the pearl pigment 10 of this example is used on a flat printing surface, the hue of the printing surface appears to change all at once depending on the angle at which the printing surface is viewed. When used on the curved printing surface of the side surface of the can body 1, the color tone of a partial area of the printing surface may change depending on the viewing angle. The decorative effect can be further exhibited.

By varying the thicknesses of the titanium oxide layer 12 and the iron oxide layer 13 formed on the flakes 11 and combining them, various interference colors and absorption colors can be obtained.

For example, when the pearl pigment 10 in which the layer of the flake 11 itself has a thickness of about 11 μm, the titanium oxide layer has a thickness of about 11 μm, and the iron oxide layer has a thickness of about 3 μm, interference is caused. A green color is obtained as a color, and a brown color (which corresponds to a dark brown color) is obtained as an absorption color. Therefore, in this case, when viewed directly from the decoration, the decoration looks like a pearl-like green color, while when viewed obliquely, it looks like a pearl-like brown color.

The layer thickness of the flakes 11 itself is about 1
When the pearl pigment 10 having a thickness of 1 μm, a thickness of the titanium oxide layer of about 9 μm, and a thickness of the iron oxide layer of about 5 μm was used, blue was obtained as the interference color and plum color (as the absorption color). This corresponds to pink). Therefore, in this case, when viewed directly from the decoration, the decoration looks like a pearl-like blue color, while when viewed obliquely, it looks like a pearl-like plum color.

Further, in the case of using the pearl pigment 10 in which the layer thickness of the flakes 11 itself is about 13 μm, the titanium oxide layer thickness is about 10 μm, and the iron oxide layer thickness is about 2 μm, Red is obtained as an interference color, and as an absorption color,
An orange color (which corresponds to the orange color) is obtained.
Therefore, in this case, the decoration looks pearly red when viewed directly from the decoration, while it looks pearly orange when viewed obliquely.

As a result, depending on the angle at which the can body 1 is viewed, it looks as if the coloring is partially completely different, and furthermore, the apparent coloring changes abruptly with the angle at which the coloring is present as the boundary. Therefore, it is possible to give a surprising impression. That is, in the metal can using the pearl pigment of the present invention for printing, due to the polarization of the pearl pigment, the green or blue or red picture displayed on the outer surface is made particularly transparent, or the brown or plum color or The orange pattern, embossing, or even the delicate irregularities of the odd-shaped can can be seen as embossed to give a three-dimensional effect.

In particular, since the side surface of the cylindrical can body 1 which is the body is not a flat surface but a curved surface, the above visual effect can be obtained without changing the viewpoint. It is possible to secure superiority in terms of aesthetics and design even with respect to the metal can using 10.

As described above, according to the can body decorated with the pearl pigment of this embodiment, the metal can is formed by forming the coating layer for coating the flakes constituting the pearl pigment into two layers. In addition to the appearance of complex color tones on the outer surface of the can, it will appear as if they are colored differently depending on the angle at which the can is viewed, so a new visual effect can be obtained and unexpectedness can be secured. As a result, it is possible to provide a metal can with a high design that reflects the image of the product housed inside.

That is, when the printed surface of the pearl pigment is directly faced, there is no difference in the length of the optical path of the reflected light reflected from each coating layer, so that the interference light of both reflected lights looks strong. On the other hand, when viewed obliquely with respect to the printing surface, there is a difference in the length of the optical path of the reflected light, so that the interference light due to both reflected lights weakens and the absorbed light looks strong.

Further, by mixing the pearl pigment in a proportion of 20 to 25% by weight with respect to the resin composition forming the printing layer, a sufficient pearly luster can be secured and
It is possible to prevent the color tone from becoming muddy.

That is, when a pearl pigment less than the above range is blended, the amount of dispersion of the pigment is small, so that the intensity of reflection with respect to incident light is lowered and the pearly luster is not sufficiently exhibited. When the pearl pigment is blended beyond the above range, the pigments aggregate with each other and uniform appearance cannot be ensured, and reflected light affects each other to give a cloudy color tone. Since the pearl pigment is blended in the resin composition in the ratio within the above range, such a situation can be avoided and the visual effect of the pearl pigment can be sufficiently exhibited.

Here, the correspondence between the structure of the embodiment and the structure of the present invention will be described. The can body 1 corresponds to the metal can of the present invention, the PET film 2 corresponds to the film of the present invention, and printing is performed. The layer 3a corresponds to a printing layer formed with a pearl ink containing the resin composition containing the pearl pigment of the present invention, and the printing layer 3b corresponds to a printing layer containing the resin composition containing the color pigment of the present invention. The adhesive layer 4 corresponds to the adhesive layer of the present invention, the pearl pigment 10 corresponds to the pearl pigment of the present invention, the flakes 10 correspond to the flakes of the present invention, and the decorative layer 30 corresponds to the decorative layer of the present invention. Equivalent to.

[0103]

As described above, according to the first aspect of the invention, the flakes constituting the pearl pigment are coated in two layers of the titanium oxide layer and the iron oxide layer, and the pearl pigment is used. By forming the decorative layer with the pearl ink and the printing ink using the color pigment, a complicated and complex color tone appears on the outer surface of the metal can, and different coloring is applied depending on the angle at which the can body is viewed. As it looks like, a new visual effect can be obtained and unexpectedness can be secured, and it is possible to provide a metal can excellent in design that can reflect the image of the product housed inside.

According to the invention of claim 2, in addition to obtaining the same effect as that of the invention of claim 1, a pearl pigment is blended in a proportion of 20 to 25% by weight with respect to the resin composition forming the printing layer. As a result, when a pearl pigment less than this range is blended, the amount of the pigment dispersed is small, so that the intensity of reflection with respect to incident light is lowered, and a pearly luster is not sufficiently expressed, and When the pearl pigment is blended beyond the range, the pigments agglomerate and the uniform appearance cannot be ensured, and the reflected lights affect each other to give a cloudy color tone. Since the pearl pigment is blended in the resin composition in the ratio of the range, it is possible to secure a sufficient pearly luster and prevent the turbid feeling from appearing in the color tone. It is possible to sufficiently exhibited.
That is, in a conventional metal can using a pearl pigment for printing, since the pearl pigment has a single-layered structure, it looks like a whitish pearl color when directly facing the outer surface of the can, and when it is viewed obliquely, it slightly polarizes. Although only the color changes, in a metal can using the pearl pigment of the present invention for printing, due to the polarization of the pearl pigment, it looks like a pearl-like green, blue or red when the outer surface of the can is directly faced, and , When viewed from an angle, it can be seen as a pearly brown or plum or orange color with polarization.

According to the invention of claim 3, in addition to obtaining the same effect as that of the invention of claim 1 or 2, the coloring of the decorative layer can be sufficiently ensured, and the printing layer containing the pearl pigment. Or, since the effect of this underprinting is added to the effect of the decoration in which the printed portion and the printed layer containing the color pigment or the printed portion are combined, a new synergistic effect can be obtained and the decoration The range of choices will be expanded, and it is possible to secure a design that meets the demands of the product.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention, and is an enlarged cross-sectional view showing the configuration of a resin film attached to the outer surface of a can body.

FIG. 2 is a schematic diagram illustrating a manufacturing process of a DI can that is a two-piece can, which is an embodiment of the present invention.

FIG. 3 is an embodiment of the present invention and is a schematic view illustrating a manufacturing process of a spectacle can that is a three-piece can.

FIG. 4 is another example of the embodiment of the present invention, and is an enlarged cross-sectional view showing the configuration of a resin film attached to the outer surface of the can body.

FIG. 5 is another example of the embodiment of the present invention, and is an enlarged cross-sectional view showing the configuration of a resin film attached to the outer surface of the can body.

FIG. 6 is an enlarged cross-sectional view showing another example of the embodiment of the present invention and showing the configuration of a resin film attached to the outer surface of the can body.

FIG. 7 is another example of the embodiment of the present invention, and is an enlarged cross-sectional view showing the configuration of the resin film attached to the outer surface of the can body.

FIG. 8 is another example of the embodiment of the present invention, and is an enlarged cross-sectional view showing the configuration of the resin film attached to the outer surface of the can body.

FIG. 9 is another example of the embodiment of the present invention, and is an enlarged cross-sectional view showing the configuration of the resin film attached to the outer surface of the can body.

FIG. 10 is another example of the embodiment of the present invention, and is an enlarged cross-sectional view showing the configuration of a resin film attached to the outer surface of the can body.

FIG. 11 is another example of the embodiment of the present invention, and is an enlarged cross-sectional view showing the configuration of the resin film attached to the outer surface of the can body.

FIG. 12 is an embodiment of the present invention, and is a schematic diagram for explaining the principle of color development that varies depending on the viewing angle of the pearl pigment.

FIG. 13 is a schematic diagram illustrating color development of a conventional pearl pigment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Can body, 2 ... PET film, 3a ... Print layer containing pearl pigment, 3A ... Print part containing pearl pigment, 3b ... Print layer for display and design images, 3.
0a ... A second printing layer formed using a low-density ink, 30b ... A printing layer formed using a low-density dark printing ink, 31A ... A printed portion formed using a low-density printing ink , 31B ... Printed portion formed of printing ink having low reflectance and high density, 4
... Adhesive layer (including the case where it is also used as a coloring layer), 5 ... Cured overcoat layer, 10 ... Pearl pigment, 11 ... Flake, 12 ... Titanium oxide layer, 13 ... Iron oxide layer,
30 ... Decorative layer.

Continued front page    (72) Inventor Shinichi Suzuki             3-6-1 Nakanogo, Shimizu City, Shizuoka Prefecture Yamato Seikan             Shimizu Plant Research Institute, Ltd. F-term (reference) 3E061 AA16 AB05 AB06 AB07 AB08                       AC02 AC05 AC09 AD01 AD03                       AD06 AD09 BA01 BA02 BB07                       DB08                 4F100 AA21H AA23H AB04 AB10                       AC05 AK01B AK01C AK01D                       AK15 AK42 AK51 AL05C                       AT00A BA04 BA10A BA10D                       CA13C DA01 DE02H GB16                       HB00C HB31C JB16D JL12B                       JN06B JN22H JN28H

Claims (3)

[Claims] 1. A resin composition in which a thermoplastic resin film is adhered to the outer surface of a can body via a resin adhesive, and a pearl pigment is contained between the resin adhesive layer and the thermoplastic resin film. And a printing ink comprising a resin composition containing a coloring pigment, and a film-attached metal can on which a decorative layer represented by a can body is formed, wherein the pearl pigment is flakes of titanium oxide. A film-attached metal can, which is characterized in that it is coated with a layer and the titanium oxide layer is coated with an iron oxide layer, and that the printed layer or the printed portion of the pearl ink develops different colors depending on the polarization of the pearl pigment. 2. The film-attached metal can according to claim 1, wherein the pearl pigment is blended in a proportion of 20 to 25% by weight with respect to the resin composition. 3. A printing layer having a reflectance lower than that of the pearl ink or the printing ink on the printing layer or the printing portion formed of the pearl ink and the can body side of the printing layer or the printing portion formed of the printing ink. The film-attached metal can according to claim 1 or 2, wherein the underprinted layer or the underprinted part is formed by.