JP3524264B2 - Film sticking can body and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a can body in which a decorative film made of a thermoplastic resin is attached to the outer surface of a metal can body, and a method for producing the can body.

[0002]

2. Description of the Related Art A so-called two-piece can made of tin or aluminum, which is a seamless metal can with an integrated bottom, is usually formed by squeezing and ironing to form a can body, followed by washing and surface treatment, followed by painting and printing. I am giving it. The mainstream printing method is a dry offset printing machine. However, in this type of printing, all colors are applied from a common blanket, so the number of colors is limited to at most 5 colors. Halftone printing was almost impossible to avoid overlapping lines.

On the other hand, in recent years, as demands from customers have become stricter, halftone printing has become a considerable level by making ingenuity in plate making and stricter printing conditions even in dry offset printing. Has been improved to. However, products are diversifying due to changes in consumption trends and needs, and there is a demand for beautiful products with a higher print quality that is required.

In order to meet such demands, as an alternative to a can obtained by directly printing on a metal can body, a preprinted thermoplastic resin film such as polyester is attached to the outer surface of the metal can body. Various cans made by wearing have been proposed. In addition to offset printing, it is possible to select gravure printing, flexographic printing, etc. as a method of making the printing film, and these printing methods have a higher decorative effect than the conventional dry offset printing method. In addition, the printing quality is quite good, and since it is printed on a continuous thermoplastic resin film instead of the can body, high-speed printing can be expected, and it has advantages that conventional dry offset printing does not have.

As a method for producing a can having a high decorative effect by heat-adhering the preprinted thermoplastic film as described above, JP-A-52-24790 and JP-A-3-230 are known.
The methods described in Japanese Patent Application Laid-Open No. 940, Japanese Patent Application Laid-Open No. 4-57747, Japanese Patent Application Laid-Open No. 7-89552 and the like are known. These will be briefly described. JP-A-52-2
According to the method described in Japanese Patent No. 4790, a printed film is attached to the can body surface of a can body that has been subjected to neck-in processing and flange processing, and the film is heat-shrinked to match the contour of the neck-in processed portion. Is the way.

In the method described in Japanese Patent Laid-Open No. 3-230940, a metal plate is first drawn or drawn and ironed to form a can body having an open end, and the can body surface of the can body is formed. This is a method in which a printed film is attached, and after that, neck-in processing and flange processing are performed on the opening end portion. And in the method described in this publication,
It is said that a thermoplastic resin film having an overcoat layer for protecting the printed layer is preferable.

Further, the method described in Japanese Patent Application Laid-Open No. 4-57747 is a method of performing neck-in processing or flange processing after adhering a printed film, and in this method, neck-in processing or flange processing. At the time of printing, in order to prevent wrinkles of the metal can on both sides of the film stacking part, the film at the planned film stacking part (corresponding to the cut point of the film) is stretched with a cylinder etc. The thickness of the overlapping part of the thermoplastic resin film of the finished film is reduced.

The method described in JP-A-7-89552 is similar to the method described in JP-A-3-230940 and JP-A-4-57747, and a printed thermoplastic resin is used. It is a method to perform necking and flange processing after attaching the film to the metal can body, but when attaching the film, overlap both ends of each other, or butt both ends of the film,
In this state, the adhesive provided on the film is used to thermally adhere to the outer surface of the can body of the heated metal can body.
Further, in order to cure the adhesive, it is further heated or irradiated with an electron beam.

[0009]

When a printed thermoplastic resin film is attached to a metal can body, it is added to prevent air entrapment and wrinkles from occurring and to attach the film securely. It is necessary to attach the film to the metal can body while applying pressure. However, the above-mentioned Japanese Patent Laid-Open No. 52-247.
In the method described in Japanese Patent Publication No. 90, the neck-in processing or the flange processing of the metal can body is performed before the printed thermoplastic resin film is adhered. It is difficult to insert into the metal can body a mandrel that is squeezed and has an outer diameter approximately equal to the inner diameter of the can body. For this reason, this method cannot increase the pressure applied to attach the film, and as a result, air is easily trapped between the film and the metal can body to cause poor adhesion, and the film is not neck-in. There is a problem that wrinkles are likely to occur in the neck-in portion when heat shrinks along the contour of the portion.

On the other hand, in the method described in Japanese Patent Laid-Open No. 3-230940, since the printed thermoplastic resin film is attached to the metal can body and then neck-in processing and flange processing are performed, the printing layer It is said that it is preferable to provide an overcoat layer for protection, and rather, the overcoat layer is considered essential. However, when both ends of the film are overlapped when attaching the film,
The slip agent such as silicone and wax contained in the overcoat layer hinders the adhesion of the film overlapping parts, and as a result, the film overlapping is performed during post-molding such as neck-in processing after film adhesion. There is an inconvenience that the part is easily peeled off. If an overcoat is not applied to eliminate such inconvenience, the outer surface of the can body becomes less slippery and the transportability of the can decreases, and the strength of the printing layer decreases and scratches occur. Problems such as easy sticking occur.

Further, according to the method disclosed in Japanese Patent Laid-Open No. 4-57747, the superposed portion of the printed thermoplastic resin film is stretched and thinned, so that the running of the film must be temporarily stopped for the stretching. Therefore, there is a problem in that the speeding up of film attachment is impeded.

Further, according to the method disclosed in Japanese Patent Laid-Open No. 7-89552, when the printed thermoplastic resin film is attached to the metal can body, if both ends of the film are overlapped with each other, the above-mentioned special feature is used. Similar to the method described in Kaihei 3-230940, there is a problem that the adhesiveness of the superposed portion is obstructed by the overcoat and peeling easily occurs at this portion. Also, instead of this, when sticking both ends of the film by abutting, since the sticking is performed under heating and the film tends to shrink, a gap is likely to occur between the abutting ends of the film, and It is very difficult to reduce the gap to zero because there are variations in the cutting length of the film and variations in the expansion and contraction of the film when applying the film. As a result, the metal base is exposed at this part and rust occurs, or when the contents are filled and the can lid is tightened, sealing failure occurs, or the butt end of the film rises during the sterilization process. There is an inconvenience that it may cause peeling.

The present invention has been made in view of the above circumstances, and prevents occurrence of wrinkles during post-forming such as neck-in processing and flange processing after sticking a printed thermoplastic resin film, In addition, it improves the slipperiness and scratch resistance of the outer surface of the can body, and can prevent rust from occurring without applying a base coat to the metal can body before attaching the film, and also prevents vapor and water during sterilization. It is an object of the present invention to provide a film sticking can body capable of preventing the film from entering the lower surface side of the film and preventing the film from rising and peeling, and a method for producing the same.

[0014]

In order to achieve the above-mentioned object, the invention of claim 1 is such that a printing layer and an adhesive layer are formed on one surface of the outer surface of the can body of a metal can body. A decorative film made of a thermoplastic resin is adhered with its both ends abutted via the adhesive layer, and an overcoat layer is formed on the entire outer surface side of the adhered decorative film. A film sticking can, wherein both ends of the decorative film are slightly separated from each other, and the overcoat layer is made of a radiation curable resin, and the radiation curable resin is both ends of the decorative film. The outer surface of the can body is covered by filling the space between the can bodies.

Therefore, according to the first aspect of the invention, since the end portions of the decorative film do not overlap each other, it is not necessary to extend the end portions of the decorative film. On the other hand, there may be a gap between the ends of the decorative film, but this part is filled with the radiation curable resin that forms the overcoat layer, and the outer surface of the can body is covered, so It is possible to prevent inconveniences such as body corrosion. Further, since the overcoat layer is formed of the radiation curable resin, it is easy to increase the film thickness of the overcoat layer, and thus it is easy to improve the scratch resistance.

According to a second aspect of the present invention, the amount of depression of the surface of the overcoat layer between both ends of the decorative film with respect to the surface of the overcoat layer on the outer surface side of the decorative film is set to 10 μm or less. Has been done. Therefore, neck-in processing of the open end of the can body,
Or, at the time of flanging, the load in the circumferential direction is less likely to be concentrated on the end portion of the decorative film, in other words,
It is unlikely to be caught by the unevenness, and as a result, it becomes easy to prevent wrinkles or peeling of the decorative film. Further, since the outer peripheral surface of the can body is smoothed as a whole, the can bodies that come into contact with each other on the outer surface of the can body slide well, and the transportability becomes good.

According to a third aspect of the present invention, a decorative film made of a thermoplastic resin, in which a printed layer and an adhesive layer made of a thermosetting resin are formed on one surface of the outer surface of a can body of a metal can body, is formed. Is a method for producing a film-attached can body, which is formed by pasting through the adhesive layer, and then performs a molding process for forming the opening end of the can body into a predetermined shape, wherein the decorative film is A film adhering step in which the decorative film is preliminarily cut to a length equal to or less than the perimeter of the can body, and the decorative film is heated and pressure-bonded to the outer surface of the can body of the can body through the adhesive layer so that both ends thereof abut each other. And an overcoat paint consisting of a radiation curable resin is applied to the outer surface side of the decorative film after attachment and applied between the abutting ends of the decorative film to overcoat the outer surface of the can body. Overcoat covered with And preparative coating step is a method which comprises a radiation step of forming an overcoat layer by by irradiating the outer surface side to cure the overcoat coating of the can body.

Therefore, in the invention of claim 3, since the end portions of the decorative film are not overlapped with each other, it is not necessary to perform a process such as extending the end portion, so that the film attaching step can be speeded up. . In addition, there may be a gap between the ends of the decorative film, but this gap is filled with overcoat paint to cover the outer surface of the can body, thus preventing rusting of the can body. In addition, invasion of sterilizing water in the sterilization process can be prevented. In other words, the undercoat for rust prevention of the can can be omitted. Furthermore, the so-called irregularities on the outer surface of the can can be eliminated and smoothed by filling the overcoat paint into the gaps between the edges of the decorative film, so that it can be used as a decorative film during the molding process in the post process such as neck-in. Inconveniences such as wrinkles can be prevented in advance.

Furthermore, if an electron beam curable adhesive and an overcoat paint are used, the adhesive layer can be simultaneously cured during the curing process of the overcoat layer by electron beam irradiation, so that the adhesive layer can be heated independently. The so-called adhesive curing step for curing can be omitted, and the process can be shortened.

According to a fourth aspect of the present invention, the overcoat paint is applied to the entire outer circumference of the decorative film at the same time by an application roll rotating at a speed higher than the peripheral speed of the can body. The method is characterized in that coating is performed between the abutting end portions of the film.

Therefore, the coating process of the overcoat paint can be speeded up including the coating of the overcoat paint into the gap between the ends of the decorative film, and the gap between the ends of the decorative film can be reduced. A sufficient amount of overcoat paint applied can be secured.

According to a fifth aspect of the present invention, the rotation speed of the coating roll is 1.1 to 1.3 times the peripheral speed of the peripheral speed of the can body.

By setting the peripheral speed of the coating roll in this way, a sufficient amount of the overcoat paint applied to the gap between the end portions of the decorative film can be secured.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described more specifically. The can body 1 of the present invention shown in FIG. 1 is made of metal, and the metal plate as a material thereof is an aluminum plate, a surface-treated steel plate such as tin-free steel, a tin plate, a chrome-plated steel plate, an aluminized steel plate. , Nickel-plated steel sheets, and other various alloy-plated steel sheets can be used. Further, as shown in FIG. 1, the can body 1 can be a can body with a bottom formed by integrally forming a can bottom and a can body such as a squeezed can, a squeezed iron can, and an impact can, that is, a two-piece can. . At the open end of this can body, neck-in processing and flange processing are finally performed to form a neck portion 1a and a flange portion 1b.

A decorative film 2 attached to the can body 1.
As the thermoplastic resin film is used, specifically, a polyethylene terephthalate resin, a polyester-based resin such as polybutylene terephthalate resin, a copolymerized polyester-based resin including a copolymer of polyethylene terephthalate and isophthalic acid, polypropylene Transparent polymer resin simple substance selected from resin, polycarbonate resin, polystyrene resin, polyolefin resin, vinyl chloride resin, polyvinylidene chloride copolymer, etc.
Alternatively, a thermoplastic resin film 2a made of a composite of the above resins is used. Above all, 60kgf / cm in the sticking process
It is preferable to use a heat-resistant polyethylene terephthalate resin in which the film is spread to some extent in the circumferential direction of the can body 1 due to the linear pressure. The thickness of the resin film 2a can be appropriately determined, and as an example, a resin film having a thickness of about 10 to 30 μm can be used.

As shown in FIG. 2, this resin film 2a
A print layer 2b and an adhesive layer 2c are sequentially formed on one surface of the first layer. That is, decorative printing is applied to one surface of the resin film 2a, and the adhesive layer 2 is applied to the surface of the printing layer 2b.
c is provided. For the printing, an ink made of a thermosetting urethane resin is used, and printing such as gravure printing and flexographic printing is performed.

The gap 3 between the abutting ends of the decorative film 2 is 0 to 0 depending on the degree of dent and the degree of wrinkle of the overcoat paint filled in the gap 3.
The decorative film 2 is appropriately selected within a range of 5 mm, and preferably the decorative film 2 is attached so that the gap 3 is about 0 to 2 mm in terms of appearance.

Furthermore, the roll to which the overcoat paint is applied is forcibly pushed into the gap 3 even if the gap 3 between the abutting ends of the decorative film 2 is very small. Therefore, it is rotated faster than the peripheral speed of the can body 1. That is, by providing a difference in peripheral speed between the can body 1 and the coating roll, rubbing occurs between the can body 1 and the coating roll, and the rubbing causes the paint on the coating roll to be scraped off. As a result, a larger amount of paint is supplied to the body surface of the can than when the overcoat paint is applied at the same speed or less, and the overcoat layer is thickened. Also, in the gap area, the paint will be scraped off at the edges of the gap, so more paint will be supplied by that amount compared to the coating surface other than the gap portion, and the excess amount will be embedded in the gap. become.

This peripheral speed difference is related to the viscosity of the overcoat paint and is 1.1 to 1.3 times the peripheral speed of the can body 1.
It is preferable to double. That is, when it is smaller than 1.1 times, the effect of scraping off the overcoat paint is small, and the gap 3 at the abutting end of the decorative film 2 is small.
It becomes uncertain that the paint will get inside, and the metal surface will be exposed easily. On the other hand, if it exceeds 1.3 times, there is no problem on the surface of the coating film, but the speed of the coating roll becomes too fast, misting or splashing occurs, and problems such as paint dripping occur.

If the gap 3 between the abutting ends of the decorative film 2, that is, the opening width of the decorative film 2 is small and both end faces of the decorative film 2 are almost in close contact with each other, the coating is applied. It is preferable to push the coating material into the minute gaps 3 by slightly increasing the coating pressure of the coating roll rather than increasing the peripheral speed of the roll.

Furthermore, for the adhesive layer 2c, it is possible to use a thermosetting adhesive which is easily adhered by heating and pressurization and has good adhesion to ink. In particular, the adhesive layer is easily protruded into the gap 3 formed by the butting of the decorative film 2 due to the pressure applied in the adhesive step, and the glass transition point (Tg) is −10 ° C. to + 40 ° C. with good fluidity and thermosetting property. A resin is preferable in order to improve the adhesiveness of the film end surface, and an adhesive containing a polyester resin, an epoxy resin and an amino resin is usually used. Further, the adhesive layer 2c is preferably provided on the entire surface of the printed layer 2b.
The adhesive is 90 to 110 mg / dm @ 2 thick.
Apply at least 50 mg / dm @ 2 over the entire surface.

On the other hand, specific examples of the electron beam (radiation) curable adhesive include polyester oligomers 2 to 2 each having an unsaturated double bond with respect to 100 parts by weight of the polyester resin.
To the resin composition mixed with 30 parts by weight, 0.5 is added a stress relaxation agent.
An electron beam curable adhesive obtained by adding up to 250 PHR (parts by weight to 100 parts by weight of resin) is used.

In the present invention, the overcoat layer 5 is formed on the decorative film 2 attached to the outer surface of the can body of the can body 1.
Is formed. The overcoat layer 5 is cured by radiation, and examples of paints therefor include epoxy acrylate resin, polyester acrylate resin, polyurethane acrylate resin, polyether acrylate resin, and polybutadiene acrylate resin. It may be a resin-like substance having a very high resin content or a low monomer-like substance, and a substance which exhibits a polymerization reaction by radiation. The radiation curable resins can be used alone or as a mixture of two or more kinds.

The radiation-curable resin can be used as it is as an overcoat paint, but a photopolymerizable monomer can be used as a reactive diluent in order to reduce the viscosity and enhance the fluidity thereof. Specific examples thereof include monofunctional monomers; difunctional monomers such as 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and tetrahydrofurfuryl acrylate;
Dicyclopentenyl acrylate, dicyclopentenialoxyethyl acrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol, neopentyl glycol diacrylate, Trifunctional or higher functional monomers such as tripropiene glycol diacrylate; trimethylolpropane triacrylate, ventaerythritol triacrylate, diventaerythritol hexaacrylate and the like.

Radiation irradiation can be employed as a means for curing the overcoat paint. Here, radiation is
It means radiation in a broad sense and includes all electromagnetic waves and particle beams. Therefore, the overcoat paint can be cured by irradiating electron beams such as X-rays, gamma rays, and beta rays. Irradiation with these electron beams is suitable when the coating film is thick. In order to perform the curing operation easily with simple equipment, ultraviolet rays (UV) in the wavelength range of about 200 to 450 nm are used.
Radiation) irradiation is adopted. When the overcoat paint is cured, the irradiation conditions under which the decorative thermoplastic resin film does not thermally shrink need to be such that the temperature of the film is 120 ° C. or less for both electron beams and ultraviolet rays. The ultraviolet irradiation is suitable for curing a thin coating film (overcoat layer), and the electron beam irradiation is suitable for curing a thick coating film (adhesive layer).

When ultraviolet rays are used as radiation,
It is preferable to incorporate a photopolymerization initiator into the overcoat coating composition. Specific examples of the photopolymerization initiator include:
Acetophenone, benzophenone, Michlerkent, benzine, benzoin, benzinisobutyl ether, benzine methyl ketal, tetramethyl thiuram sulfide, azobisisobutyronitrile, benzoyl peroxide, ditert-butyl peroxide, 1-hydroxycyclohexyl phenyl ketone, 2 -Chlorothioxanthone and the like. These photopolymerization initiators may be used alone or in combination of two or more kinds.

The curing time depends on the thickness of the decorative film 2, the radiation source, the photopolymerization initiator, the reactive diluent and the distance between the radiation source and the coating surface to be cured,
0.1 second to 1.0 second is preferable in order to improve the production efficiency.

In the method of the present invention, the above-mentioned decorative film 2 is adhered to the can body and then the overcoat paint is applied thereon. As the coating method, a roll coater, a gravure coater, a spray coating method or the like is adopted.

In the method of the present invention, as an example, as shown in the process chart of FIG. 3, first, a printing layer 2b and an adhesive layer 2c are provided on the surface of the metal can body 1 that is in close contact with the can body surface. The thermoplastic resin film 2 is cut into a length equal to or slightly shorter than the circumference of the body of the can body 1, that is, cut into a length equal to or less than the circumference of the body, and then the can body 1 is heated to a predetermined temperature in advance. Both ends of the decorative film 2 are pressed against each other via the adhesive layer 2c by heat and pressure to stick the decorative film 2 to the surface of the can body. In that case, as shown in FIG. 4, both ends of the decorative film 2 are abutted against each other, but the decorative film 2 is cut to be equal to or slightly shorter than the circumference of the can body. , A gap 3 may be formed in a portion where the ends thereof are butted against each other.

The can body 1 to which the decorative film 2 is adhered in the attaching step is subjected to a solventless radiation curability in the next coating step after a predetermined time for lowering the temperature of the can body 1 to which the film has been attached. Overcoat paint is applied. When a roll is used for the coating, the peripheral speed of the coating roll is set to be 1% faster than the peripheral speed of the can body 1 in order to positively fill the gap 3 formed at the abutting portions of the decorative film 2 with the coating material. 1 ~
Rotate the coating roll to be 1.3 times faster.

In the can body 1 in which the outer surface of the can body 1 is coated with the overcoat paint, a slight gap 3 between both ends of the decorative film 2 is filled with the overcoat paint as shown in FIG. As a result, even if the end portions of the decorative film 2 are separated from each other, the outer surface of the can body in that portion is covered with the overcoat paint, and the contact with the outside air is blocked.

Further, the filling amount of the overcoat paint in the portion of the gap 3 is the other general surface, that is, the decorative film 2
The amount is such that it does not form a depression with respect to the surface of the overcoat paint on the outside. That is, the depression of the overcoat layer 5 in the gap 3 is suppressed. In that case, since the peripheral speed of the coating roll is relatively high, the overcoat paint on the coating roll is applied to the outer surface of the can body 1. Therefore, in the gap 3, the overcoat paint is positively applied. Supplied. In the gap 3, the coating roll is rubbed against the edge of the gap 3 so that the paint is scraped off. Therefore, more paint is supplied by that amount and the remaining amount of the paint is supplied into the gap 3. Is filled.

Next, the overcoat paint applied to the outer peripheral surface of the decorative film 2 is cured by irradiating it with radiation in the radiation irradiating device. Since the paint is a solvent-free type and has a solid content of 100%, there is almost no decrease in volume, that is, decrease in coating thickness during the curing reaction process. That is, dents generated in the gaps 3 at both ends of the decorative film 2 are suppressed, and a relatively flat cured (dry) coating film is formed on the outer peripheral surface of the can.

Therefore, the overcoat layer 5 is
Since the entire outer surface of the decorative film 2 is covered and the gap 3 between the abutting ends of the decorative film 2 is filled, even if the gap 3 is formed between the ends of the decorative film 2. As a whole of the can body 1, a uniform surface having no dent visually is formed. Therefore, not only does it look good, but there is no portion where the outer surface of the can body is exposed to the outside air, so rust is prevented from occurring.

Further, since the overcoat layer 5 made of a radiation curable resin is formed on the entire outer peripheral surface of the decorative film 2 of the can body 1 after the film is adhered, the coating film hardness of the surface of the can body 1 becomes high. Since the overcoat layer is made higher than the overcoat layer made of a curable resin and the overcoat paint is made of a radiation curable resin, it is not necessary to heat it during curing and deformation of the decorative film 2 due to thermal contraction is prevented.

Then, the adhesive is cured. This may be performed according to the composition of the adhesive layer provided on the decorative film 2. For example, when a thermosetting resin is used, heat treatment is performed, and when a radiation curable resin is used. For example, an appropriate radiation such as an electron beam is applied.

After the decorative film 2 is attached to the can body as described above, the can body 1 is sent to the next step, and neck-in processing (especially die-neck processing) is applied to the opening end of the film-attached can. Give. In that case, the entire circumference of the can body is covered with the overcoat layer 5, and the gap 3 at the abutting portion of the decorative film 2 is made of a radiation curable resin that becomes relatively hard when cured. Since the coat paint is sufficiently embedded and the overcoat layer 5 is flattened over the entire circumference, the compressive force acting in the circumferential direction on the neck is made uniform over the entire circumference, and stress concentration can be prevented. Wrinkles and opening of the film edge are prevented. further,
Since the metal body of the can body 1 is not exposed, rust is not generated, and it is possible to prevent the decorative film 2 from being lifted or peeled at the abutting portion of the decorative film 2 which is likely to occur in the sterilization process, and the gap 3 is also included. Since it is visually flattened and finished neatly, the appearance quality can be improved.

A can body 1 to which a decorative film 2 is attached
When applying an electron beam curable overcoat to the can body surface of
If an electron beam curable adhesive is used, it is possible to cure the overcoat paint by electron beam irradiation and at the same time accelerate the curing of the adhesive. That is, the heat curing step of the adhesive can be omitted, and the adhesive can be cured together in the electron beam irradiation step. A process diagram in that case is shown in FIG.

[0049]

EXAMPLES The present invention will now be described in detail based on examples. First, a device for carrying out the method of the present invention will be briefly described. FIG. 7 is a schematic view showing the entire structure thereof, in which a large number of mandrels 6 are spaced apart from each other on a circle having a predetermined turning radius. Are arranged so as to maintain and rotate. These mandrels 6 are cylindrical members having a diameter slightly smaller than the inner diameter of the target metal can body 1,
Each is configured so that it can rotate about the central axis.

On the other hand, the metal can body 1 fitted and held on the outer periphery of the mandrel 6 is a so-called two-piece can body 1 which is formed as a cylindrical body with a bottom by drawing and ironing an aluminum disc, for example. There is no neck-in processing or flange processing. Conveying means (not shown) for arranging and conveying the two-piece cans 1 in a line
Of the two-piece can 1 carried by the carrying means is pushed by the pushing means (not shown) to be fitted into the mandrel 6. The two-piece cans 1 are put on and delivered to the mandrel 6 one by one.

The mandrel 6 is continuously swung in the direction of the arrow in FIG. 7, and the mandrel 6 is swung forward from the supply station 7 of the two-piece can 1 in the swirling direction of the mandrel 6. The heating device 8 is arranged outside over a predetermined range. The heating device 8 is for heating and raising the temperature of the two-piece can 1 held by the mandrel 6, and as an example, a high frequency induction heating device can be adopted. The mandrel 6 is configured to rotate on its own axis in the range where the heating device 8 is arranged.

A portion adjacent to the heating device 8 on the front side in the turning direction of the mandrel 6 is a bonding station 9.
In the bonding station 9, a decorative film 2 made of a thermoplastic resin having a print layer 2b and an adhesive layer 2c formed on one surface in this order is attached to the can body surface of the heated two-piece can 1. Attached. In the bonding station 9, the bonding roll 10 is arranged outside the turning radius of the mandrel 6.

This sticking roll 10 comprises a plurality of the decorative films 2 cut into a length substantially equal to or less than the circumference of the can body surface of the two-piece can 1, and the adhesive layer 2c. The ornamental film 2 adsorbed on the outer surface of the ornamental film 2 is adsorbed and held on the outer peripheral surface thereof at a constant interval, and is rotated in synchronization with the turning of the mandrel 6.
Is attached to the can body surface of the two-piece can 1. The adhesive pressure in that case can be adjusted to an appropriate pressure by adjusting the distance between the sticking roll 10 and the mandrel 6.
As an example, a linear pressure of about 40 kgf / cm to 60 kgf / cm can be set. As the means for adsorbing and holding the decorative film 2, various conventionally known means can be adopted, and for example, vacuum adsorbing may be adopted.

The can body 1 is attached to the bonding station 9 described above.
The overcoat station 11 is provided on the downstream side in the flow of FIG. The overcoat station 11 is a portion where the decorative film 2 is attached to the can body surface by the above-mentioned bonding station 9 and then an overcoat paint made of a radiation curable resin is applied to the outer peripheral surface of the decorative film 2. The overcoater 12 is arranged outside the turning radius of the mandrel 6. The overcoater 12 is a roll coater composed of an applicator roll 13 and two metering rolls 14, and transfers the paint measured in a small gap between the two metering rolls 14 to the applicator roll 13. The overcoat paint on the surface of the applicator roll 13 is applied to the entire outer peripheral surface of the two-piece can 1, that is, the outer surface of the decorative film 2 attached to the can body surface.

The applicator roll 13 is rotated at a peripheral speed of the mandrel 6, that is, a peripheral speed higher than that of the can body 1, for example, 1.1 to 1.3 times the peripheral speed of the can body 1. Due to this peripheral speed difference, the paint is forcibly embedded in the minute gap of the film butting portion, and the coating is applied in a state in which the occurrence of the dent of the overcoat layer 5 at the butting portion of the decorative film 2 is suppressed. ing.

In applying the overcoat paint to the can body 1, it is necessary to lower the temperature of the can body 1 with the film attached to room temperature in order to prevent the paint from foaming. There is. For example, as shown in FIG. 7, transfer units 16 in which pockets 15 are provided on the circumference at regular intervals may be provided between the step of attaching the decorative film 2 and the overcoat station 11. . With such a configuration, the film-attached can body 1 is extracted from the mandrel 6 by using pneumatic means (not shown) such as air, and is transferred to the mandrel 6 of the overcoat station 11. It is possible to secure a time for lowering the temperature of the can body 1.

A discharge station 17 is provided on the front side of the overcoat station 11 in the turning direction of the mandrel 6. This discharge station 17
Removes the can body 1 fitted on the mandrel 6 from the mandrel 6 by using a discharge means such as air, transfers it to a conveyor (not shown), and conveys it to the next radiation irradiation step 18. ing.

In the radiation irradiation step 18, since the smoothness of the overcoat coating surface coated on the entire outer peripheral surface of the can body is obtained, the passage time from the overcoat application to the radiation irradiation can be secured for 10 seconds or more. Thus, it is provided at a front position away from the overcoat station 11.

In the radiation irradiating step 18, radiation lamps and the like are arranged in a predetermined range on both sides of the conveying path for supporting and conveying the can body 1 by a rotating pin or the like.
While the can body 1 is rotated several times, the overcoat paint applied to the outer peripheral surface of the film of the can body 1 is hardened so that the overcoat layer 5 has almost no dent at the relatively flat butted portion over the entire peripheral surface of the can body. Are formed. Here, the radiation irradiator uses an electron beam, for example, an X-ray, a gamma ray, a beta ray, or an ultraviolet ray, but it radiates an ultraviolet ray in a wavelength range of about 200 to 450 nm which is easily and economically cured. Is preferably used.

On the front side of the radiation irradiating step 18, the film sticking can body 1 supported by the carrying means is pulled out from the pin, and the can body 1 is moved to the next side by a predetermined carrying means (not shown). It is designed to be transported to the subsequent process where inner surface painting, neck-in processing and flange processing are performed. Further, when it is necessary to heat and cure the adhesive after the film attaching step, it is necessary to provide an adhesive curing step 19 between the radiation irradiation step 18 and the subsequent step.
It is heated and cured at the same time by utilizing the paint baking process of the internal coating process of the subsequent process. Therefore, when an electron beam curable resin is used for the adhesive and the overcoat paint of the decorative film 2 or when the adhesive is cured by using a paint baking process as a subsequent process, the dotted line in FIG. The enclosed adhesive curing step 19 is omitted.

Next, the method of the present invention using the above apparatus will be specifically described. The metal can body 1 fitted and held on the outer periphery of the mandrel 6 is, for example, a two-piece can body that is formed as a cylindrical body with a bottom by squeezing and ironing a tin plate, and is not subjected to neck-in processing or flange processing. It has not been applied. The can body 1 is washed and then dried. Then, the can body 1 is sent to the supply station 7 by a predetermined conveying means, and is delivered to the mandrel 6 there.
That is, the two-piece can 1 is fitted in the mandrel 6 that is rotating on the circumference of a predetermined radius at the supply station 7, and the mandrel 6 holds the can body 1 in that state. Then, the can body 1 is rotated together with the mandrel 6 on a circle having a predetermined radius and rotated.
While passing through the front side of the heating device 8 adjacent to the supply station 7, it is heated by high frequency induction, and the surface temperature of the can body is heated up to about 120 ° C. at which thermal shrinkage does not occur in the decorative film.

On the other hand, the decorative film 2 is provided with the printing layer 2b on one surface of the thermoplastic resin film 2a, with a length range approximately equal to the circumferential length of the can body surface of the two-piece can body 1 as one section. An adhesive layer 2c is provided on the upper side of the print layer 2b. The decorative film 2 is cut into sections each having a length that is substantially the same as or slightly shorter than the circumference of the can body surface of the can body 1 and is adsorbed to the sticking roll 10 in the bonding station 9. In addition, each cut decorative film 2
Are adsorbed and held on the outer peripheral surface of the sticking roll 10 at the same intervals as the mandrel 6, and are held with the adhesive layer 2c on the outside. Further, the sticking roll 10 rotates in synchronization with the turning speed of the mandrel 6, that is, the turning speed of the two-piece can body 1. As an example, the decorative film 2 is rotated at a high speed of 100 m / min so as to be supplied.

Therefore, when the can body 1 heated and heated by the heating device 8 reaches the bonding station 9, the decorative film 2 is pressed against the can body surface by the bonding roll 10 and bonded by the bonding layer 2c. . The pressing force is a linear pressure of 30 kgf / cm. Further, the can body 1 rotates together with the mandrel 6, the decoration film 2 is attached to the entire outer surface of the can body without entrapment of air, and the decoration film 2 is attached between the abutting ends of the decoration film 2. The film 2 is attached in a state where both end surfaces of the film 2 are in close contact with each other, or is attached with a minute gap 3 (about 2 mm) formed.

The can body 1 to which the decorative film 2 is thus adhered is held by the mandrel 6 and sent to the overcoater 12 while rotating on its axis, where the applicator roll 13 contacts the outer peripheral surface of the can body 1. As a result, the radiation-curable overcoat paint becomes the above-mentioned decorative film 2
Applied to the outer peripheral surface of. In that case, the rotation speed of the applicator roll 13 is 1.1 to the peripheral speed of the can body 1.
The peripheral speed is 1.3 times, specifically 1.2 times the peripheral speed.

Since the overcoat paint applied in this way exhibits a highly viscous fluidity in the wet state,
Applicator roll 1 that rotates faster than the peripheral speed of the can body 1.
3 is forcedly pushed into the minute gap 3 between the abutting ends of the decorative film 2, and fills the minute gap 3. In this case, the can body 1 and the applicator roll 1
Since rubbing is always generated between No. 3 and 3, the coating material on the applicator roll 13 is applied to the body surface of the can in a fashion of being scraped off, and the coating surface is formed thick. In addition, in the gap portion, the paint on the applicator roll 13 is scraped off at the edge of the gap, so that extra paint is supplied by that amount and the excess amount is pushed into the gap by the applicator roll 13. Therefore, the gap is filled, and the outer surface of the can body 1 is covered and shielded from the outside air. As a result, the dent of the overcoat layer hardly occurs in the gap portion.

In this way, the can body 1 in which the radiation curable resin is overcoated on the decorative film 2 is swivelly moved to the discharge station 17 on a predetermined radius circumference together with the mandrel 6, and The mandrel 6 is transferred to the transfer conveyor, and the transfer conveyor is transferred to, for example, a pin chain. The pin chain irradiates radiation (ultraviolet rays) while passing through the radiation irradiation device, and the overcoat layer 5 is cured and formed. .

The can body 1 to which the decorative thermoplastic resin film 2 is adhered in this way is, after the adhesive curing step,
Fig. 1 is taken out from the pin chain and transported to the subsequent process.
As described above, the inner surface and the bottom surface of the can body 1 are coated by a known method, and the opening end is subjected to neck-in processing or flange processing by a known method to manufacture a film-bonded can body 1 '. It

Next, examples of the present invention will be shown together with comparative examples.

[0069]

Example 1 A film sticking can was manufactured using a tinned two-piece can body (350 ml can having a can body inner diameter of 65.8 mm) that was squeezed and ironed. The decorative film 2 is shown in FIG.
As shown in a schematic sectional view in Fig. 1, one surface of the polyethylene terephthalate resin film 2a having a thickness of 16 µm is divided into a range of the same length as the circumference of the outer circumference of the can body of the can with ink made of urethane resin. As a gravure printed layer 2b having a thickness of 1 μm, a polyester resin, an isocyanate resin and an amine resin (compounding ratio 94:
3: 3) and a thermosetting adhesive layer 2c having a thickness of 6 μm were formed.

As the overcoat paint, a transparent paint made of an ultraviolet curable resin is used, and the overcoat paint is surely embedded in the gap 3 between the abutting ends of the decorative film in the overcoat application process. At the same time, in order to obtain a smooth coated surface, 70% by weight of epoxy acrylate resin as a prepolymer, 30% by weight of triacrylate as a photopolymerizable monomer, 5 to 7% by weight of benzophenone as a photopolymerization initiator, As a lubricant, 1 to 2% by weight of silicon is uniformly mixed, and Ford cup # 4.25 ° C. is used for 60 to 90 seconds (200 to 350 c
The viscosity was adjusted to p).

In the overcoat station 11, the overcoat paint was applied by the overcoater 12 to the entire outer circumference of the decorative film. During this coating, the rotation speed of the applicator roll 13 of the overcoater 12 was 1.2 times the peripheral speed of the can body. As a result, the wet overcoat paint was sufficiently filled in the minute gaps formed between the abutting ends of the decorative film, and the minute gaps were almost completely filled.

In the radiation irradiation step, a wavelength of 200 to
The overcoat paint was cured by irradiating it with UV light of 450 nm for 0.5 seconds. Overcoat layer 5 after curing
Since the solvent was solvent-free, the paint loss due to the curing of the paint was extremely small, and a paint film surface was formed which almost maintained the wet paint film surface. As a result, no depression of the film abutting portion of the overcoat layer in the minute gap 3 or exposure of the metal surface of the can body 1 occurred.

In this embodiment, the well-known epoxy-phenolic paint is spray-coated on the inner surface and the bottom surface of the two-piece can 1 sent out from the radiation irradiation step 18, then the coating is dried and the adhesive is heated. Heated at 220 ° C. for 60 seconds for curing. After that, the open end of the can body 1 was subjected to three-step neck-in processing (neck inner diameter 57.4 mm) and flange processing by a known method.

When the can 1 thus obtained was visually inspected, no wrinkles or cracks were found in the neck-in processed portion, and the decorative film 2 was not peeled off at all. Further, coffee liquid was filled in the can body 1 and sealed by a conventional method, and retort sterilization treatment was performed at 125 ° C. for 30 minutes. No bleaching of the blister or the decorative film 2 occurred and the appearance was printed. The layer 2b was protected by the transparent decorative film 2 and the overcoat layer 5, and a beautiful film sticking can without scratches was obtained.

In order to investigate the influence of the peripheral speed difference between the coating roll (applicator roll) of the overcoat paint and the can body 1 and the gap (opening width) between the abutting ends of the decorative film 2, the opening width is determined. 0.5 mm, 1.0 mm to 5.
The results shown in FIG. 8 were obtained when the thickness was varied in 5 steps of 1.0 mm up to 0 mm. That is, the opening width is 2.
If it was 0 mm or less, no wrinkles were generated during neck-in processing, but if the opening width was 3.0 mm and 4.0 mm, minor wrinkles were generated on the decorative film due to neck-in processing, When the opening width was 5.0 mm, relatively small wrinkles occurred.

Further, in order to investigate the influence of the opening width of the decorative film, an experiment was conducted under different conditions, and the results shown in FIG. 9 were obtained. That is, the opening width is 0.5 to 2.0 m
In the case of m, no wrinkles were observed during neck-in processing. On the other hand, the opening width is 3.0 to 5.0 mm
In the case of, slight wrinkles occur during neck-in processing,
When the opening width was 6.0 mm or more, the coating film was not damaged, but relatively small wrinkles occurred during the neck-in processing.

Further, in order to investigate the influence of the dent on the overcoat layer, an experiment was conducted by changing the dent amount, and the results shown in FIG. 10 were obtained. The definition of the dent amount is as shown in FIG. 11, and is the other general surface (the surface of the overcoat layer on the outer surface side of the decorative film) of the lowest portion of the overcoat layer in the gap. To dimension D.

That is, the radiation-curable overcoat paint can be made to have a solid content of 100%, and as a result, when the opening width is narrow, the dent becomes zero because there is no volume reduction during the curing process. On the other hand, when the opening width increases, the coating surface decreases due to the influence of surface tension during coating,
This appears as a dent amount.

Therefore, when the opening width was 5.0 mm or less, and when the dent amount between the abutting ends of the decorative film was 10 μm or less, no wrinkles were generated during neck-in processing. When the opening width was 6.0 mm or more and the dent amount was 15 μm or more, relatively small wrinkles occurred so that the coating film was not damaged during neck-in processing.

[0080]

Example 2 Using an electron beam curable resin as an adhesive,
Other conditions were the same as in Example 1 to produce a film sticking can.

As an adhesive composed of an electron beam curable resin,
A mixture of 2 to 20 parts by weight of a polyester oligomer having an unsaturated double bond and 0.5 to 250 PHR (parts by weight with respect to 100 parts by weight of resin) of a polyester resin was used per 100 parts by weight of the polyester resin.

A decorative film having the above-mentioned adhesive layer,
The can body was cut into a length equal to or less than the perimeter, and the cut body was attached to the outer surface of the can body. Then, the can was passed through an electron beam irradiation device, and an electron beam of 3 Mrad was irradiated to cure the adhesive layer.

A known epoxy-phenolic paint was spray-coated on the inner surface and the bottom surface of the obtained can body, and the paint was dried at 220 ° C. for 60 seconds. After that, neck-in processing and flange processing were performed on the open end of the can body by a known method.

Also in this example, no wrinkles or cracks were found in the necked portion, and the decorative film was not peeled off at all. Further, when the retort sterilization treatment was carried out under the same conditions as in Example 1, no blister or whitening occurred, and a beautiful film sticking can could be obtained.

[0085]

Comparative Example 1 In order to investigate the influence of the peripheral speed of the coating roll of the overcoat paint, the peripheral speed of the applicator roll was set to be the same as the peripheral speed of the can body to apply the overcoat paint. Other conditions were the same as in Example 1 to prepare a decorative film sticking can.

The results are shown in FIG. 8 together with the results of Example 1. That is, when the opening width at both ends of the film was 0.5 mm, no dent was particularly formed in the overcoat layer, and no wrinkles were formed in the decorative film during the neck-in processing. On the other hand, when the opening width was 1.0 mm or more, the embedding of the overcoat paint was insufficient and a partial dent on the coated surface occurred in the gap between the abutting ends of the decorative film.
When the neck processing is applied, the opening width is 1.0 to 3.
In the case of 0 mm, slight wrinkles were generated, and in the cases of the opening widths of 4.0 mm and 5.0 mm, small wrinkles were generated with the neck-in processing to the extent that the coating film was not damaged.

Comparing this result with the result of Example 1 described above, when the peripheral speed of the coating roll of the overcoat paint is higher than the peripheral speed of the can body, the filling of the overcoat paint into the gap is sufficient. As a result, it is recognized that it is possible to effectively prevent the dent of the overcoat layer and the wrinkling of the decorative film due to the molding process such as the neck-in process resulting from the dent.

[0088]

Comparative Example 2 In order to investigate the influence of the gap (opening width) between the abutting ends of the decorative film, an experiment was conducted for the case where there was no overcoat layer and the case where a thermosetting overcoat paint was used. The conditions for the decorative film were the same as in Example 1. The results are shown in FIG. 9 together with the results of Example 1.

When the overcoat layer is not formed,
With the thickness of the decorative film as the depth and the opening width as the opening width, a recess (dent) is formed on the outer surface of the can body. In this case, if the opening width is 2.0 mm or less, Wrinkles at the time of neck-in processing stop only slightly,
When the opening width is 3.0 mm or more, relatively small wrinkles occur, and particularly when the opening width is 6.0 mm or more, wrinkles large enough to damage the coating film occur.

When a thermosetting overcoat paint is used, a relatively noticeable dent occurs between the abutting ends of the decorative film due to the volume reduction due to the evaporation of the solvent. As a result, the wrinkle situation of the decorative film due to the neck-in processing was the same as that when the overcoat layer was not formed.

Therefore, comparing these results with the results of Example 1, when the radiation-curable overcoat paint shown in Example 1 is used, the overcoat layer is unlikely to be dented, and therefore the opening width is increased. It is recognized that the wrinkles of the decorative film due to the neck-in processing can be effectively suppressed even if the size becomes large to some extent.

[0092]

[Comparative Example 3] In order to investigate the influence of the overcoat paint on the amount of dents and the influence of the dents on the generation of wrinkles, an experiment was conducted for the case without an overcoat layer and the case of using a thermosetting overcoat paint. went. The conditions for the decorative film were the same as in Example 1. The experimental results are shown in FIGS. 9 and 10 together with the results of Example 1.

When the overcoat layer is not formed,
The thickness of the decorative resin film (23 μm) becomes the dent amount as it is. When a thermosetting overcoat paint is used, the volume of the solvent decreases in the gap due to volatilization of the solvent, and the dent amount is 14 μm regardless of the opening width.
Became.

The occurrence of wrinkles in the decorative film due to the neck-in processing was the same as in the case of Comparative Example 2 described above. That is, regardless of whether there is no overcoat layer or when a thermosetting overcoat paint is used, if the opening width is 2.0 mm or less, wrinkles during neck-in processing will be minimal. When the opening width is 3.0 mm or more, relatively small wrinkles occur,
In particular, when the opening width was 6.0 mm or more, wrinkles that were large enough to damage the coating film occurred.

Therefore, comparing these results with the results of Example 1, when the radiation-curable overcoat paint shown in Example 1 was used, even when the opening width was large, the overcoat layer was The amount of dents can be suppressed,
Accordingly, it is recognized that the wrinkles of the decorative film due to the neck-in processing can be effectively suppressed.

[0096]

Comparative Example 4 A can body was prepared by using a decorative film provided with an overcoat layer in advance and adhering it to the outer surface of the can body with the ends thereof abutted against each other. A steel two-piece can body was used as the can body, and the decorative film was directly attached to the outer surface of the can body without applying a base coat.

As a result, a gap 3 is formed between the abutting ends of the decorative film 2. Further, using this, a beverage can was prepared by a predetermined method and subjected to warm water sterilization treatment at 80 ° C. × 30 minutes and retort sterilization treatment at 125 ° C. × 30 minutes, and rust 20 was generated at part A in FIG. did.

[0098]

Comparative Example 5 A thermosetting resin was used as the overcoat paint. The other conditions are the same as in Example 1. Example 1
After sticking the decorative film shown in to the outer surface of the can,
A 50% solids thermosetting resin was overcoated and passed through a hot air oven to heat cure the overcoat paint.

The overcoat layer had dents between the abutting ends of the decorative film, and when this was necked in, wrinkles were observed regardless of the opening width. The result is shown in FIG. Note that FIG. 13 also shows the result when the overcoat layer shown in Comparative Example 2 is not provided.
As is known from FIG. 13, when a thermosetting resin is used as an overcoat paint, the amount of dents becomes large, which causes wrinkles on the decorative film during neck-in processing. The degree is the same as when the overcoat layer is not provided.

In Example 1 described above, the inner surface of the can body was painted after the decorative film was attached and the overcoat layer was formed.
It may be performed prior to the application of the decorative film. When the coating of the inner surface is preceded, the proportion of those having a large current value slightly increases due to defects in the coating film such as scratches in the coating film. In addition, when the inner surface is painted first, it is naturally necessary to perform the heating process only for overcoating. Therefore, considering these technical factors, it is considered preferable to coat the inner surface in a later step.

The present invention can be applied to metal cans other than two-piece cans, and can be similarly applied to devices other than the device shown in FIG.

[0102]

As described above, according to the first aspect of the present invention, the gap formed between the abutting ends of the decorative film is filled with the overcoat paint and the outer surface of the can body is covered. Even if the edges of the film are not completely abutted against each other, it is possible to prevent rust from occurring and prevent the decorative film from rising by preventing the entry of sterilizing water in the heat sterilization process. be able to. In other words, the base coat for rust prevention can be omitted, and the cost can be reduced.

Further, since the overcoat layer is made of a radiation curable resin, a solventless one can be used, and therefore, reduction in volume at the time of curing and sink or sink in the above-mentioned gap can be prevented or suppressed. Therefore, the surface of the overcoat layer on the decorative film and the surface of the overcoat layer in the gap can be a continuous smooth cured surface, and as a result, the surface of the film sticking can body has a smooth surface without irregularities. Therefore, no clearance is created between the tooling and the can during the neck-in processing or the flange processing, and it is possible to effectively prevent wrinkles and film peeling at the neck portion. Therefore, a film-attached can body having a beautiful appearance can be obtained, which can prevent a sealing failure in a canned product in which the contents are filled and the can lid is wound.

Particularly, as described in claim 2, when the dent amount of the overcoat layer in the gap is 10 μm or less, wrinkles and peeling of the decorative film during molding such as neck-in processing are further effective. Can be prevented.

As described above, since the overcoat layer is formed of the radiation curable resin, the film thickness can be increased, and accordingly, the coating film hardness on the surface of the film sticking can body is increased to improve the resistance. It is possible to improve the scratch resistance and improve the luster, and effectively prevent scratches and peeling of the film from the abutting end of the decorative film due to contact between the cans during transportation and transportation. it can. At the same time, since the cans are not caught with each other, the transportability of the cans is improved.

Further, since the overcoat layer is made of a radiation curable resin, it is not necessary to heat it for curing, and therefore, the thermoplastic resin film is prevented from being deformed due to heat shrinkage and has a good appearance. You can

On the other hand, according to the third aspect of the present invention, since the decorative film having a length equal to or less than the circumference of the body of the can is attached to the can, the edges of the decorative film do not overlap with each other. Part processing (processing such as stretching and thinning the planned overlapping portion of the decorative film) is not required, and overcoating the entire outer periphery of the can by applying the overcoat paint after the decorative film is attached. I'll cover it with paint,
Even if there is a gap between the abutting ends of the decorative film, that part is covered with the overcoat paint and is shielded from the outside air, so the rust resistance of the film sticking can can be ensured. it can.

In particular, in the invention described in claim 4, since the peripheral speed of the roll for applying the overcoat paint is set to be higher than the peripheral speed of the can body, the overcoat paint for the gap between the abutting ends of the decorative film is In the invention described in claim 5, the peripheral speed difference can be 1.1.
Since it is set to ~ 1.3 times, it is possible to surely fill the above-mentioned gap with the overcoat paint, and by removing the unevenness of the surface of the film sticking can, the decoration at the time of molding processing such as neck-in processing. Wrinkles and peeling of the film can be prevented in advance.

Since the overcoat layer is applied and formed after the decorative film is attached to the can body, the overcoat layer should be thicker than when the decorative film provided with the overcoat layer is used. In this respect, the scratch resistance can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a metal can body targeted by the present invention.

FIG. 2 is a schematic sectional view of a decorative film used in the present invention.

FIG. 3 is a process chart for explaining an example of the method of the present invention.

FIG. 4 is a schematic cross-sectional view of a film butting part in the film sticking can according to the present invention.

FIG. 5 is a schematic cross-sectional view showing a state after an overcoat layer is formed in the film abutting portion.

FIG. 6 is a process drawing for explaining another example of the method of the present invention.

FIG. 7 is an overall schematic view showing a decorative film sticking device that can be used in the present invention.

FIG. 8 is a table showing the experimental results in Example 1 and Comparative Example 1 conducted to investigate the influence of the peripheral speed of the coating roll of the overcoat paint.

FIG. 9 is a table showing the results of experiments in Example 1 and Comparative Example 2 conducted to investigate the influence of the distance between the abutting ends of the decorative film.

FIG. 10 is a table showing the results of experiments in Example 1 and Comparative Example 3 conducted to investigate the effect of the distance between the abutting ends of the decorative film and the amount of indentation.

FIG. 11 is a diagram for explaining the definition of a dent in the overcoat layer between the abutting ends of the decorative film.

FIG. 12 is a partial cross-sectional view schematically showing a situation in which a film having an overcoat provided in advance is attached to a can body to cause rust.

FIG. 13 is a chart showing the results of wrinkling of the decorative film in Comparative Example 4 using the thermosetting overcoat paint.

[Explanation of symbols]

1 ... Two-piece can (can body), 2 ... Decorative film,
2a ... Thermoplastic resin film, 2b ... Printing layer, 2c
... Adhesive layer, 5 ... Overcoat layer, 8 ... Heating device,
9 ... Adhesion station, 11 ... Overcoat station, 18 ... Radiation irradiation step.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-89552 (JP, A) JP-A-4-57747 (JP, A) JP-A-5-124648 (JP, A) JP-A-5- 112361 (JP, A) JP-A 2-80139 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65D 25/00 B65D 1/00 B65D 8/00

Claims (5)

(57) [Claims] 1. A state in which a decorative film made of a thermoplastic resin having a printing layer and an adhesive layer formed on one surface thereof is abutted to the outer surface of a can body of a metal can body with both ends thereof abutted through the adhesive layer. In the film sticking can body having an overcoat layer formed on the entire outer surface side of the stuck decorative film, the both ends of the decorative film are slightly separated from each other, and The overcoat layer is made of a radiation curable resin,
A film sticking can body characterized in that the radiation curable resin is filled between both ends of the decorative film to cover the outer surface of the can body. 2. The dent amount of the surface of the overcoat layer between both ends of the decorative film with respect to the surface of the overcoat layer on the outer surface side of the decorative film is set to 10 μm or less. The film sticking can body according to claim 1. 3. A decorative film made of a thermoplastic resin having a printing layer and an adhesive layer made of a thermosetting resin formed on one surface on the outer surface of the can body of a metal can body, with the adhesive layer interposed therebetween. After sticking, in the method for producing a film-sticking can body in which the opening end of the can body is molded into a predetermined shape, the decorative film is precut to a length equal to or less than the circumference of the can body, A film attaching step of heat-pressing the decorative film to the outer surface of the can body of the can body heated so that both ends thereof face each other through the adhesive layer, and an overcoat paint made of a radiation curable resin. An overcoat coating step of coating the outer surface side of the decorative film after sticking and coating between the abutting ends of the decorative film to coat the outer surface of the can body with an overcoat paint, Outside of body And a radiation irradiation step of forming an overcoat layer by irradiating the coating composition with radiation to cure the overcoat coating material. 4. The overcoat paint is applied to the entire outer circumference of the decorative film by a coating roll rotating at a speed higher than the peripheral speed of the can body, and at the same time, the abutting end of the decorative film is applied. The method for producing a film sticking can according to claim 3, wherein the film sticking can is applied between the two. 5. The film sticking can body according to claim 4, wherein the rotation speed of the coating roll is 1.1 to 1.3 times the peripheral speed of the can body speed. Manufacturing method.