JPH11170684A - Printing method to curved surface body and curved surface printing body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a precise print image easily on a curved surface body, in particular, on the outer surface of a packaging container by printing ink on a film base body for formation of a transfer sheet after being cured, and transferring the printed layer of the transfer sheet on the surface of a curved body in a manner allowing it to be opposite to an adhesive film formed on the surface of the curved body. SOLUTION: Ink is printed on the film base body 1 of a plastic film or the like, and after being cured, a transfer sheet 10 is formed having a print layer 2 capable of separating a cellophane tape. On the other hand, a UV curable primer is applied on the surface of a curved body, e.g. a can cylinder 3 to then irradiate UV ray thereto for formation of an adhesive film 4. After that, the print layer of the transfer sheet 10 and adhesive film 4 are opposed to transfer the print layer 2 on the surface of the curved body 3 through separation of the film base body 1. The adhesive film 4 having the transferred print layer 2 is cured immediately by UV irradiation or heating, or treated such that a clear paint is applied on the print surface 2 to subsequently be cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for printing on a curved body and a curved printed body, and more particularly, to a method for forming a fine print image on the surface of a curved body and an overlap portion on the surface. The present invention relates to a novel printing method capable of beautiful printing without defects and a curved printed body obtained by this method.

[0002]

2. Description of the Related Art Printing on the outer surface of a packaging container has an important meaning for displaying the contents and enhancing the commercial value, but printing on the packaging container is not limited to printing on a flat surface. Printing on a curved surface is also one of the important things.

[0003] The cans for cans are roughly classified into two types: side seam cans (three-piece cans) having a seam on the side and seamless cans (two-piece cans). In the former side seam can, a means is used in which a flat material is printed and then formed into a cylindrical shape to form a seam. On the other hand, in the latter case, a metal material such as an aluminum plate, a tin plate or a tin-free steel plate is used.
Forming at least one stage of drawing between the drawing die and the punch to form a cup having a seamless body on the side surface and a bottom integrally connected to the body seamlessly; The part of the container is thinned by bending or stretching, or by ironing between an ironing punch and an ironing die.

This seamless can has no seams at the bottom and sides of the container, has excellent appearance characteristics, has a thinner can side wall, and has a lighter container.
It has the advantage that the amount of material used can be saved, but has the limitation that printing must be performed on the curved surface of the molded can.

Conventionally, for printing on a curved body portion of a seamless can, a lithographic plate is used as a printing plate, a printing ink layer is once transferred to a blanket roller, and then the ink layer on the blanket roller is transferred to the curved surface of the can body. The method is adopted.

[0006]

However, in the above-mentioned conventional printing method, it is difficult to form a fine print image composed of a large number of halftone dot aggregates such as gravure printing, and the print image is inevitably monotonous. There is a disadvantage that it is easy to become something.

Further, in order to transfer from the blanket roller to the curved surface of the can body, a wrap portion of the printing ink layer is formed,
In this wrapped portion, the color density is higher than that in the non-wrapped portion due to the overlapping of the ink layers, which impairs the appearance of the outer surface of the can body.

Accordingly, it is an object of the present invention to provide a printing method capable of forming a fine print image composed of a large number of halftone dot aggregates on a curved body, particularly on the outer surface of a packaging container. It is another object of the present invention to provide a printing method and a printed body capable of forming a printing ink layer without a printing wrap portion on an outer surface of a curved body.

[0009]

According to the present invention, there is provided a process for printing and curing an ink on a film substrate to form a transfer sheet having a print layer releasable from a cellophane tape; The method comprises applying a curable primer, irradiating ultraviolet rays to form an adhesive film, and transferring the print layer to the curved surface by facing the print layer and the adhesive film. The present invention provides a method for printing on a curved surface body. According to the present invention, further, a step of applying a primer to the membrane substrate and curing to form a coating layer capable of peeling off the cellophane tape, and further printing ink on the release layer, curing and having a print layer A step of forming a transfer sheet, a step of applying an ultraviolet-curable primer to the surface of the curved body, irradiating ultraviolet rays to form an adhesive film, and a step of facing the print layer and the adhesive film with the print layer. Transferring the release layer to the surface of the curved body. A method for printing on a curved body is provided. In the printing method of the present invention, after the transfer step, the adhesive coating can be cured by ultraviolet irradiation or heat treatment, or, after the transfer step, a clear paint is applied on the print layer, and the clear coating film together with the adhesive coating is applied. It can be cured by ultraviolet light or heat treatment. Further, the present invention can be advantageously applied to a case where the ink of the transfer sheet is an ultraviolet-curable ink having cure shrinkage, and a case where the easily peelable primer of the transfer sheet is an ultraviolet-curable resin having cure shrinkage. It can be advantageously applied when the membrane substrate is a plastic film, especially a polyester or polyolefin film. According to the present invention, further comprising a curved body, an ultraviolet-curable primer layer applied to the surface of the curved body, and a printing ink layer applied by transfer to the primer layer, wherein the printing ink layer has an overlap portion. Is provided substantially without a curved surface.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Operation] In FIG. 1 for explaining an example of the printing method of the present invention, in step 1, first, ink is printed on a film substrate 1 such as a plastic film, cured, and the cellophane tape is peeled off. A transfer sheet 10 having a possible printing layer 2 is formed. In step 2, an ultraviolet-curable primer is applied to the surface of the curved body, for example, the surface of the can body 3, and is irradiated with ultraviolet light to form the adhesive film 4.
In step 3, the printing layer 2 is transferred to the surface of the curved body 3 by facing the printing layer 2 and the adhesive coating 4 and peeling the film substrate 1. The adhesive coating 4 to which the printing layer has been transferred in this manner may be immediately cured by ultraviolet irradiation or heating, or, as shown in Step 4, a clear coating 5 is applied on the printing layer 2 to form a clear coating. 5 can be cured together with the adhesive film 4 by ultraviolet light or heat treatment.

In FIG. 2 for explaining another example of the printing method of the present invention, instead of the step 1 in FIG. Step 1A of forming a transfer sheet having the print layer 2 is performed in Step 1A of forming the transfer sheet having the print layer 2 by printing and curing the ink on the coating layer 6. It is the same as FIG. 1 except that the peeling is performed between the release coating layer 6.

The first feature of the printing method of the present invention is that a printing layer is provided on a film substrate such as a plastic film in a detachable state directly or via a cured primer layer. Due to this feature, according to the present invention, printing and transfer in a planar shape can be performed, and there is no restriction on curved surface printing. Therefore, precise printing including an aggregate of halftone dots such as gravure printing can be performed.

The second feature of the printing method of the present invention is that an ultraviolet-curable primer is applied to the surface of the curved body and is irradiated with ultraviolet light to form an adhesive film. Although the ultraviolet-curable paint is a material known per se, in the present invention, in the middle of the curing of the ultraviolet-curable paint, focusing on the fact that there is a stage in which the film shows extremely stable tackiness,
The adhesive film before curing is used as a receiving layer of the printing layer. That is, the printing layer and the adhesive film are faced to each other and pressed, and the film substrate is peeled off, so that the printing layer can be transferred to the curved surface, and the adhesive film after the transfer of the printing layer is irradiated with ultraviolet light. Alternatively, by curing by heating, it is possible to firmly bond the printing layer having the above-mentioned characteristics on the curved body.

In addition, the curved printed body according to the present invention has a novel feature which is not recognized in the conventional curved printed body. That is, in FIG. 3 showing a seam of a printing layer between the conventional curved print body and the curved print body of the present invention, as shown in FIG. Even if there is some error in the overlapped portion, the overlapped portion 7 where the print layers 2 are overlapped with each other so as not to cause a missing portion of the print.
Is formed. On the other hand, in the curved print according to the present invention, even if the seam 8 exists in the print layer 2, the seam 8 is formed by abutting the print layers, and there is no overlap as in the related art. It does not. In the printing method of the present invention,
The printing layer can be transferred only when the adhesive film is present on the surface of the curved body. However, at the seam 8 of the printing layer, the adhesive film is already covered with the printing layer. This is because the printing layer is no longer transferred to the portion covered with the printing layer.

As described above, according to the present invention, it is possible to form a precise printed image composed of a large number of halftone dot aggregates on a curved body, particularly on the outer surface of a packaging container. In addition, it is possible to form a printing ink layer without a printing wrap portion, and this printed body has an advantage that it has excellent appearance characteristics.

The present invention has the following additional advantages in addition to the advantage that the transfer of the print layer can be reliably performed by using an ultraviolet curable paint as the primer layer serving as the base of the print layer. Things. In other words, the primer layer adheres to and protects the metal or the coated metal, and also adheres firmly to the print layer to hold it firmly. At the time, especially at the time of high-speed coating, there is an advantage that mist scattering can be prevented.

FIG. 4 of the accompanying drawings plots the relationship between the amount of coating film (wet) per can and the amount of generated mist with respect to the base paint (white coating) having a solid content of 40% while changing the coating speed. Things. According to FIG. 4, when the amount of coating film (wet) per can increases,
When the amount of generated mist increases and the coating speed increases,
Although the amount of generated mist increases, it is understood that the amount of generated mist rapidly increases when the amount of coating film exceeds a certain reference value at any coating speed.

On the other hand, FIG. 5 is a plot of the relationship between the amount of coating film (wet) per can and the amount of generated mist for a base coating material having a solid content of 80% while changing the coating speed. However, in this case, the amount of mist
It can be seen that the effect is suppressed to a significantly lower level than in the case of and the effect of the coating speed is smaller.

When an ultraviolet-curable undercoat is used, the amount of mist is reduced due to the reduced content of the solvent, and the required amount of coating (wet) is also reduced due to the high solids content. It can be significantly reduced, and an excellent working environment can be maintained.

The present invention can be applied to a case where the ink of the transfer sheet is an ultraviolet-curable ink having a curing shrinkage and the case where the easily peelable primer of the transfer sheet is an ultraviolet-curable resin having a curing shrinkage. This provides an advantage that a beautiful printed image having a certain quality can be applied to the outer surface of the curved body.

In general, ultraviolet-curable inks and ultraviolet-curable resins have curing shrinkage to a greater or lesser degree,
In particular, when the curing shrinkage is conspicuous, when printed or coated on the outer surface of a package or the like and cured by ultraviolet rays, the disadvantage that a dull appearance with a matte appearance is likely to occur. On the other hand, according to the present invention, an ultraviolet-curable ink or an ultraviolet-curable resin is applied to a base film, and after curing, these are transferred to an adhesive film. And the advantage that the appearance characteristics are remarkably improved.

[Outline of Printing Method] The printing method of the present invention
1 and FIG. 2, which show the UV-curable primer coating step, the UV-curing step, the transfer step, and the final curing step. In FIG. 6, a turret 11 for primer coating, a turret 12 for curing, The printing image transfer unit 13 and the final curing turret 14 are arranged adjacent to each other, and the can 15 is rotatably held around these turrets so as to rotate and revolve.

A primer coating unit 16 is arranged along the periphery of the turret 11 for primer coating, and the molded and trimmed two-piece can 15 is
It is supplied to the coating turret 11 by the supply mechanism 17,
An ultraviolet curable primer is applied to the outer surface of the side wall by the primer application unit 16.

The curing turret 12 has an ultraviolet light source 18 around it, and the painted cup 15a moves onto the curing turret 12 and is irradiated by the ultraviolet light source 18 provided therearound, so that the primer layer is adhered. UV curing of the primer layer is performed so that

Cup 15 with partially cured primer layer
b is sent to the print image transfer unit 13, and comes into pressure contact with the transfer sheet 19 sent in synchronization with the rotation of the cup 15b, whereby the printing layer on the transfer sheet is transferred to the surface of the cup 15b.

The final curing turret 14 is provided with an infrared light source or an ultraviolet light source 20 around it. The cup 15c having the printed layer transferred onto the adhesive film is transferred to the final curing turret 14 to heat the infrared light source. Or by the ultraviolet light from an ultraviolet light source.

[Curved body] The curved body used in the printing of the present invention is one which is formed on a curved surface and then printed, and generally has a cylindrical shape, but has a cylindrical shape such as a tapered shape (cup shape) or a bulge shape. The body may have a deformed form.
The curved body targeted by the present invention is preferably a packaging container having the above-mentioned shape, and the constituent material of the curved body is metal, coated metal, plastic, paper, glass, or a laminate of two or more of these. May be any material. Hereinafter, the present invention is drawn or deep drawn of metal or coated metal,
A seamless can formed by drawing and ironing will be described, but the present invention is of course not limited to this example.

The two-piece can used for printing in the present invention is manufactured by drawing-redrawing or drawing-ironing of a metal material or an organic-coated metal material. An organic-coated metal plate may be formed into a cup, or a metal cup may be provided with an organic coating later.However, in terms of ease and simplicity of manufacture, an organic-coated metal plate is formed into a cup. It is suitable.

In FIG. 7 showing an example of a cross-sectional structure of the two-piece can, in FIG. 7, a cup 30 includes a metal base 31, an inner organic coating 32 provided on the inner surface thereof, and an outer organic coating 32 provided on the other surface of the base. And a coating 34. In FIG. 8 showing another example of the cross-sectional structure, an inner organic coating 32a is applied to a metal base 31 formed in a cup by a later coating, and an extraordinary organic coating is provided on the outer surface of the metal base 31. Although no coating has been formed, the exterior surface is painted and printed as previously noted and detailed below.

In the present invention, various surface-treated steel plates and light metal plates such as aluminum are used as the metal plate.

As the surface-treated steel sheet, a cold-rolled steel sheet is annealed and then subjected to secondary cold rolling, and is subjected to one or more surface treatments such as zinc plating, tin plating, nickel plating, electrolytic chromic acid treatment, and chromic acid treatment. Can be used.
An example of a suitable surface-treated steel sheet is an electrolytic chromic acid-treated steel sheet, particularly provided with a chromium metal layer of 10 to 200 mg / m ² and a chromium oxide layer of 1 to 50 mg / m ² (in terms of chromium metal). This is excellent in the combination of coating film adhesion and corrosion resistance. Another example of a surface-treated steel plate is a hard tin plate having a tin plating amount of 0.5 to 11.2 g / m ² . This tin plate is desirably subjected to chromic acid treatment or chromic acid / phosphoric acid treatment so that the amount of chromium is 1 to 30 mg / m ^{2 in} terms of metal chromium. As still another example, an aluminum-coated steel sheet subjected to aluminum plating, aluminum pressure welding, or the like is used.

As the light metal plate, an aluminum alloy plate is used in addition to a so-called pure aluminum plate. An aluminum alloy sheet excellent in corrosion resistance and workability has a Mn of 0.1.
2 to 1.5% by weight, Mg 0.8 to 5% by weight, Zn
The composition has a composition of 0.25 to 0.3% by weight, 0.15 to 0.25% by weight of Cu, and the balance of Al. It is desirable that these light metal plates have also been subjected to a chromic acid treatment or a chromic / phosphoric acid treatment such that the chromium amount becomes 20 to 300 mg / m ^{2 in} terms of chromium metal.

Thickness of metal plate, ie thickness of can bottom (tB)
Has a thickness of 0.10 to 0.5 mm in general, though it depends on the type of metal, the use or the size of the container, and among them, in the case of a surface-treated steel sheet, it is preferable that the thickness be 0.1 mm.
The thickness is preferably 10 to 0.3 mm, and in the case of a light metal plate, 0.15 to 0.40 mm.

The organic coating optionally provided on the metal substrate may be a thermoplastic resin, a thermosetting resin, or a composition thereof, but is preferably a thermoplastic resin. When the metal base is an aluminum base, the resin coating on the outer surface may be omitted as shown in FIG.

As the thermoplastic resin coated on the metal plate, a crystalline thermoplastic resin is preferable, and examples thereof include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, and ethylene Olefin resin films such as acrylic ester copolymers and ionomers; polyethylene terephthalate;
Polyesters such as polybutylene terephthalate and ethylene terephthalate / isophthalate copolymer; polyamides such as nylon 6, nylon 6,6, nylon 11 and nylon 12; polyvinyl chloride; polyvinylidene chloride;

The coating layer of the thermoplastic resin contains an inorganic filler (pigment) for the purpose of concealing the metal plate and assisting the transmission of wrinkle pressing force to the metal plate at the time of drawing and redrawing. Can be. In addition, a compounding agent for a film known per se, for example, an antiblocking agent such as amorphous silica, various antistatic agents, a lubricant, an antioxidant, and an ultraviolet absorber may be added to the film according to a known formulation. it can.

Examples of the inorganic filler include rutile-type or anatase-type inorganic white pigments such as titanium dioxide, zinc white, and gloss white; barite, precipitated barite sulfate, calcium carbonate, gypsum, precipitated silica, aerosil, talc, calcined or the like. Are white clay pigments such as unfired clay, barium carbonate, alumina white, synthetic or natural mica, synthetic calcium silicate, magnesium carbonate; black pigments such as carbon black and magnetite; red pigments such as redwood; yellow pigments such as siena Blue pigments such as ultramarine blue and cobalt blue. These inorganic fillers can be incorporated in an amount of 10 to 500% by weight, particularly 10 to 300% by weight, based on the resin.

The coating of the coated thermoplastic resin on the metal plate is performed by a heat fusion method, dry lamination, extrusion coating method, or the like, and the adhesiveness (thermal fusion property) between the coated resin and the metal plate.
When the content is insufficient, for example, a urethane-based adhesive, an epoxy-based adhesive, an acid-modified olefin resin-based adhesive, a copolyamide-based adhesive, a copolyester-based adhesive, or the like can be interposed.

It is desirable that the thickness of the thermoplastic resin is generally in the range of 3 to 50 μm, particularly 5 to 40 μm. In the case of heat fusion using a film, it may be unstretched or stretched.

As a particularly preferred film, a polyester mainly composed of an ethylene terephthalate unit or a butylene terephthalate unit is formed into a film by a T-die method or an inflation film-forming method. A film produced by stretching and heat setting the stretched film can be mentioned.

As the raw material polyester, polyethylene terephthalate itself can be used under the conditions of stretching, heat setting and laminating, which are extremely limited. However, lowering the maximum crystallinity that the film can reach requires impact resistance and processability. For this purpose, it is preferable to introduce a copolymer ester unit other than ethylene terephthalate into the polyester for this purpose. It is particularly preferable to use a biaxially stretched film of a copolymerized polyester mainly composed of ethylene terephthalate units or butylene terephthalate units and containing a small amount of other ester units and having a melting point of 210 to 252 ° C. The melting point of homopolyethylene terephthalate is generally from 255 to 265 ° C.

Generally, at least 70 mol%, especially at least 75 mol%, of the dibasic acid component in the copolymerized polyester is composed of the terephthalic acid component, and at least 70 mol%, especially at least 75 mol%, of the diol component is ethylene glycol or butylene glycol. Consisting of 1 to 30 mol% of the dibasic acid component,
In particular, it is preferable that 5 to 25 mol% is composed of a dibasic acid component other than terephthalic acid.

Examples of dibasic acids other than terephthalic acid include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid and naphthalenedicarboxylic acid: alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; succinic acid, adipic acid, sebacic acid, dodecane One or a combination of two or more aliphatic dicarboxylic acids such as dionic acid, and diol components other than ethylene glycol or butylene glycol include propylene glycol, diethylene glycol,
One or more of 1,6-hexylene glycol, cyclohexane dimethanol, an ethylene oxide adduct of bisphenol A and the like can be mentioned. Of course, the combination of these comonomers must be such that the melting point of the copolyester is within the above range.

The copolyester used should have a molecular weight sufficient to form a film and for this purpose it has an intrinsic viscosity (IV) of 0.55 to 1.9 dl / g, in particular of 0.1 to 0.1 dl / g.
Those in the range of 65 to 1.4 dl / g are desirable.

The stretching of the film is generally carried out at 80 to 110 ° C.
At a temperature of, the area stretching ratio is preferably in the range of 2.5 to 16.0, particularly 4.0 to 14.0.
It is good to carry out in the range of 30 ° C.

The copolyester film is preferably biaxially stretched, and the degree of biaxial orientation can be confirmed by a polarization fluorescence method, a birefringence method, a density gradient tube method, or the like.

In laminating, in order to prevent excessive crystallization, the time required for the laminated film to pass through the crystallization temperature range is shortened as much as possible. To pass within. For this,
During lamination, only the metal material is heated, and the laminate is forcibly cooled immediately after laminating the film. For cooling, direct contact with cold air or cold water or pressure contact of a forcedly cooled cooling roller is used. It is to be understood that the degree of crystal orientation can be relaxed by heating the film to a temperature near the melting point during the lamination and quenching after lamination.

When an adhesive primer is used, it is generally desirable that the surface of the film be subjected to a corona discharge treatment in order to enhance the adhesion to the adhesive primer to the film. The degree of the corona discharge treatment was such that the wetting tension was 44
Desirably, it should be dyne / cm or more.

In addition, the film may be subjected to a known surface treatment for improving adhesion such as plasma treatment or flame treatment or a coating treatment for improving adhesion of urethane resin or modified polyester resin. .

The adhesive primer optionally provided between the polyester film and the metal material exhibits excellent adhesion to both the metal material and the film. A typical primer paint excellent in adhesion and corrosion resistance is a phenol epoxy paint composed of a resol type phenol aldehyde resin derived from various phenols and formaldehyde, and a bisphenol type epoxy resin, Particularly, a phenol resin and an epoxy resin are mixed in a ratio of 50: 5.
0 to 5:95 weight ratio, especially 40:60 to 10:90
Is a paint contained in a weight ratio of

The adhesive primer layer generally has a thickness of 0.3 to 5
The thickness is preferably set to μm. The adhesive primer layer may be provided in advance on a metal material or may be provided in advance on a polyester film.

The polyester layer serving as a metal coating can be provided by a so-called extrusion coat instead of being applied in the form of a biaxially stretched film. In this extrusion coating method, a web of a molten resin extruded from a die is supplied onto a heated metal substrate, and is quenched immediately after pressing by a laminating roll.

As the thermosetting resin paint used for coating,
For example, phenol-formaldehyde resin, furan-
Formaldehyde resin, xylene-formaldehyde resin, ketone-formaldehyde resin, urea formaldehyde resin, melamine-formaldehyde resin, alkyd resin, unsaturated polyester resin, epoxy resin, bismaleimide resin, triallyl cyanurate resin, thermosetting acrylic resin, silicone Resin, oily resin, or the above-mentioned thermosetting resin and thermoplastic resin paint, for example, vinyl chloride-
Examples thereof include a vinyl acetate copolymer, a vinyl chloride-maleic acid copolymer, a vinyl chloride-maleic acid-vinyl acetate copolymer, an acrylic polymer, and a composition with a saturated polyester resin. These resin coatings may be used alone or in combination of two or more.

Among the above thermosetting resin coatings, a combination of an epoxy resin (a) and a curing agent resin (b) for the epoxy resin is preferable.

Among these curing agent resins, a phenol-formaldehyde resin, particularly a phenol-aldehyde resin component containing a polycyclic polyphenol, is used.
It is desirable in terms of adhesion to the film, barrier properties against corrosive components, and processing resistance.

Forming into a two-piece can (seamless can) can be carried out by means known per se, for example, drawing-redrawing, drawing-redrawing-ironing, drawing-bending and redrawing, drawing-bending-drawing and ironing. And so on.

For example, deep drawing (drawing-redrawing)
According to the pre-draw cup formed from the coated metal plate,
It is held by an annular holding member inserted into the cup and a re-drawing die located thereunder. A redrawing punch is arranged coaxially with the holding member and the redrawing die so as to be able to enter and exit the holding member. The redrawing punch and the redrawing die are relatively moved so as to mesh with each other.

As a result, the side wall of the front drawing cup is bent perpendicularly inward from the outer peripheral surface of the annular holding member via the curvature corner thereof to the annular bottom surface of the annular holding member and the upper surface of the redrawing die. And is bent almost vertically in the axial direction by the working corner of the redrawing die, so that a deep drawing cup having a smaller diameter than the front drawing cup can be formed.

Further, the radius of curvature (Rd) of the working corner portion of the redrawing die is set to 1 to 2.9 of the metal plate thickness (tB).
By making the dimensions twice, especially 1.5 to 2.9 times, the thickness of the side wall can be effectively reduced by bending and pulling. In addition, the variation in the thickness between the lower portion and the upper portion of the side wall portion is eliminated, and uniform thickness reduction can be achieved over the whole. Generally, the side wall portion of the can body has a thinning rate (variation in thickness) of 5 to 45% (-5 to-) with respect to the blank thickness (tB).
45%), especially 5 to 40% (-5 to -40%).

In the case of a deep drawn can, the following formula (1) In the formula, D is the diameter of the sheared laminate material, and d is the punch diameter.
To 3.0, and preferably 1.5 to 5.0 in total.

Further, an ironing die is arranged at the rear of the redrawing or bending and redrawing, and the following formula (2) is applied to the side wall portion. In the formula, tB is the thickness of the base plate, and tW is the thickness of the side wall portion. The ironing rate RI defined by 5 to 70%, particularly 10 to 60%, may be reduced by ironing. it can.

At the time of drawing or the like, various lubricants, for example, liquid paraffin, synthetic paraffin, edible oil, hydrogenated edible oil, palm oil, various natural waxes, and polyethylene wax are applied to the coated metal plate or the cup to form. Good to do. The amount of the lubricant applied varies depending on the type of the lubricant, but it is generally preferably in the range of 0.1 to 10 mg / dm ² , particularly preferably in the range of 0.2 to 5 mg / dm ^2. It is performed by spraying the surface in a state.

In order to improve the drawability of the cup,
It is advantageous to set the temperature of the resin-coated drawing cup in advance in the range of not less than the glass transition point (Tg) of the coated resin, particularly not more than the thermal crystallization temperature, and mold the resin coating layer in a state in which plastic flow is facilitated. is there.

The molded organic cup on the inner surface side after molding is
After so-called trimming, in which the ear portion of the cup opening is cut, the printing process is performed. Prior to the trimming process, the cup after molding is removed from the glass transition point (T
g) or more and heating to a temperature lower than the melting point, so that the distortion of the coating resin can be alleviated. This operation is particularly effective in the case of a thermoplastic resin in order to increase the adhesion between the coating and the metal.

[Ultraviolet curable primer] In the present invention,
An ultraviolet curable resin is used as a primer to be an adhesive film. In the case where the final curing of the primer layer is carried out by ultraviolet rays, this paint contains an ultraviolet-curable resin and a catalyst, and is roughly classified into (1) a cationically curable type and (2) a radical polymerization type. There are things. When the final curing of the primer layer is performed by heating,
(3) A paint having ultraviolet curability and imparted with thermosetting properties by irradiation with ultraviolet rays or (4) a paint having both ultraviolet curability and heat curability is used. Hereinafter, examples will be described, but the present invention is not limited to these examples.

(1) Cation-Curable Coating As the UV-cationic polymerization coating, a combination of an ultraviolet-curing epoxy resin and a photocationic polymerization catalyst is used.

The ultraviolet-curable epoxy resin includes an epoxy resin component having an alicyclic group in a molecule and an adjacent carbon atom of the alicyclic group forming an oxirane ring. For example, an epoxy compound having at least one epoxycycloalkane group, for example, an epoxycyclohexane ring, an epoxycyclopentane ring, or the like is used alone or in combination.

Suitable examples include, but are not limited to,
Vinylcyclohexene diepoxide, vinylcyclohexene monoepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 2- (3,4-epoxycyclohexyl-5,
5-spiro-3,4-epoxy) cyclohexane-m-
Dioxane, bis (3,4-epoxycyclohexyl)
Adipate, limonenedoxide, and the like.

The cationic ultraviolet polymerization initiator used in combination with the above-mentioned epoxy resin is one which is decomposed by ultraviolet rays to release a Lewis acid, and this Lewis acid has an action of polymerizing an epoxy group. An aromatic iodonium salt, an aromatic sulfonium salt, an aromatic selenium salt, an aromatic diazonium salt and the like can be mentioned.

Examples of the diallyliodonium salt include diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluorophosphate, 4-chlorophenyliodonium tetrafluoroborate, di (4-methoxyphenyl) iodonium chloride, and (4-methoxyphenyl) phenyl And iodonium.

Examples of the triarylsulfonium salt include, for example, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphate, p- (phenylthio) phenyldiphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroantimonate, and 4-chloro Phenyldiphenylsulfonium hexafluorophosphate and the like.

Examples of the triarylselenium salt include triphenylselenium hexafluorophosphate, triphenylselenium hexafluoroantimonate and the like.

As other cationic polymerization initiators,
(2,4-cyclopentagen-1-yl) [(1-methoxythiethyl) -benzene] -iron-hexafluorophosphate, diphenylsulfonium hexafluoroantimonate, dialkylphenylsulfonium hexafluoroantimonate, dialkylphenylsulfonium Hexafluorophosphate, 4,4'-bis [di (β-hydroxyethoxy) phenylsulfonio]
Phenylsulfide-bis-hexafluoroantimonate, 4,4-bis [di (β-hydroxyethoxy) phenylsulfonio] phenylsulfide-bis-hexafluorophosphate and the like can be mentioned.

The cationically curable coating composition may contain a known cationically polymerizable vinyl monomer, a diluent, another epoxy resin, a sensitizer, a crosslinking agent, and the like.
As the cationic polymerizable vinyl monomer, ethylene glycol divinyl ether, ethylene glycol monovinyl ether, propylene glycol divinyl ether, propylene glycol monovinyl ether, butylene glycol monovinyl ether, hexanediol monovinyl ether, neopentyl glycol monovinyl ether, glycerol divinyl ether, Examples include glycerol trivinyl ether, trimethylolpropane divinyl ether, trimethylolpropane trivinyl ether, diglycerol trivinyl ether, sorbitol tetravinyl ether, aryl vinyl ether, and phenyl vinyl ether.

Examples of the diluent include phenyl glycidyl ether, methylphenyl glycidyl ether, n-butyl glycidyl ether, low viscosity compounds having an oxirane ring such as 1,2-epoxyhexadecane, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether And polyhydric alcohol derivatives such as diethylene glycol monoalkyl ether and dipropylene glycol monoalkyl ether, and alcohols such as propanol, isopropanol, butanol and isobutanol.

Other epoxy resins for modification include bisphenol-type epoxy resins derived from bisphenols such as bisphenol A and bisphenol F and epichlorohydrin, and novolak-type phenol resins and epichlorohydrin. Novolak type epoxy resin is used.

As a sensitizer, a thioxanthone derivative,
Examples include 2,4-diethylthioxanthone and 2,4-diisopropylthioxanthone.

Examples of the crosslinking agent include various polyols such as ε-caprolactone triol.

A suitable example of a cationically curable paint formulation is:
Although not limited thereto, the cationic UV initiator may be used in an amount of 0.5 to 10 parts by weight, particularly 1 to 5 parts by weight, a diluent 0 to 20 parts by weight, particularly 0 to 10 parts by weight, per 100 parts by weight of the alicyclic epoxy resin. 0 to 20 parts by weight, especially 0 to 15 parts by weight of another epoxy resin, 0 to 20 parts by weight, particularly 0 to 10 parts by weight of a cation polymerizable vinyl monomer, and 0 sensitizer.
To 2 parts by weight, in particular, 0 to 30 parts by weight of a crosslinking agent.

(2) Ultraviolet Radical Curable Coating As the ultraviolet radical polymerization coating, a combination of an ultraviolet curable monomer or prepolymer and a photopolymerization catalyst is used.

As the ultraviolet-curable monomer or prepolymer, a monomer or prepolymer having a plurality of ethylenically unsaturated groups in a molecule or a mixture thereof is used. Suitable examples include epoxy acrylate resin, urethane acrylate resin, thermosetting acrylic resin, thermosetting polyester resin and the like.

Examples of the epoxy acrylate resin include an adduct of a bisphenol type epoxy resin and an ethylenically unsaturated carboxylic acid such as acrylic acid or methacrylic acid, or an adduct of the bisphenol type epoxy resin and an ethylenically unsaturated polycarboxylic acid anhydride such as A reaction product with maleic anhydride, itaconic anhydride or the like is used.

Examples of the urethane acrylate resin include a urethane acrylate resin obtained by reacting an isocyanate-terminated polyester or an isocyanate-terminated polyol with a functional group-containing acrylic monomer such as acrylic acid, methacrylic acid, hydroxyethyl (meth) acrylate and the like. Is used.

Examples of the thermosetting acrylic resin include 1,6-hexanediol diacrylate (HDDA), 1,6-hexanediol dimethacrylate (HDDMA), neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, and ethylene glycol diacrylate. Acrylate (EGD
A), ethylene glycol dimethacrylate (EGDMA), polyethylene glycol diacrylate (PEGMA-A), polyethylene glycol dimethacrylate (PEGMA), polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, butylene glycol dimethacrylate, butylene glycol dimethacrylate, penta Erythritol diacrylate, 1,4-butanediol diacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate,
Pentaerythritol triacrylate, dipentaerythritol hexaacrylate, tetramethylolmethanetetraacrylate, N, N, N ', N'-tetrakis (β
(Hydroxyethyl) ethylene diamine acrylate, 2,2-bis [4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl) propane and the like are used.

Examples of the thermosetting polyester resin include polyesters containing an ethylenically unsaturated bond in the molecule, for example, ethylenically unsaturated polycarboxylic acids such as maleic acid, fumaric acid, itaconic acid and tetrahydrophthalic acid. , Isophthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, combinations with other acid components such as polymerized fatty acids, and ethylene glycol, diethylene glycol, propylene glycol, glycerin, neopentyl glycol, trimethylolpropane, pentane Polyester resins obtained by condensation with polyhydric alcohols such as erythritol and bisphenols are used.

The above-mentioned polyfunctional monomers or prepolymers are usually used in combination with monofunctional monomers. Examples of such monomers include acryloyl morpholine, glycidyl acrylate (GA) and glycidyl methacrylate (GMA). ), Carbitol acrylate,
Tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, dicyclopentadienyl acrylate, dihydrodicyclopentadienyl methacrylate, isobornyl acrylate, acrylamide (AA
m), methacrylamide (MAm), N-methylolacrylamide (N-MAM), N-diacetoneacrylamide (DAA
M), N-vinylpyrrolidone, maleic acid, itaconic acid,
Methyl methacrylate (MMA), ethyl acrylate (E
A), styrene (ST), acrylonitrile (AN), vinyl acetate
(VAc), vinyl toluene (VT), etc.

Further, divinylbenzene, diallyl phthalate (DAP), diallyl isophthalate, diallyl adipate, diallyl glycolate, diallyl maleate, diallyl sebacate, triallyl phosphate,
Other polyfunctional monomers such as triallyl aconitate, allyl trimellitate, allyl pyromellitic acid and the like may also be used.

Representative examples of the photoradical initiator include benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether and alkyl ethers thereof; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino -Propane-
Acetophenones such as 1-one; anthraquinones such as 2-methylanthraquinone and 2-amylanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4
-Thioxanthones such as diisopropylthioxanthone, ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone and xanthones.

The photo-radical initiator can be used in combination with one or more known and known photo-polymerization accelerators such as benzoic acid or tertiary amine.

In the radical-curable coating composition, the photo-radical initiator is used in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the ultraviolet-curable resin.
It is preferably used in a proportion of 1 part by weight, preferably 1 to 25 parts by weight.

(3) Paint having UV curability and imparting thermosetting properties by irradiation with UV rays The paint of type (3), ie, the UV- and thermocation-polymerizable resin composition, includes the above-mentioned UV-cationic polymerizable resin. A combination of a monomer or prepolymer, a cationic photopolymerization catalyst and a thermal cationic polymerization catalyst is used.

Examples of the thermal cationic polymerization initiator include sulfonium salt-based thermal polymerization initiators, for example, C (manufactured by Asahi Denka Kogyo KK).
P-66, CP-77 and the like are used.

Suitable examples of the formulation of the cation-curable resin composition with ultraviolet light and heat include, but are not limited to, 50 to 90 parts by weight of an alicyclic epoxy resin, 0.5 to 5 parts by weight of a cationic ultraviolet light polymerization initiator, Cationic thermal polymerization initiator
1 to 2 parts by weight, diluent 0 to 20 parts by weight, other epoxy resin 1 to 20 parts by weight, cationic polymerizable vinyl monomer 0 to 10 parts by weight, sensitizer 0 to 2 parts by weight, crosslinking agent 0 to 0 parts by weight It consists of 30 parts by weight.

In the case where a coating material having ultraviolet curability and imparting thermosetting property by irradiation with ultraviolet rays is used, and the heat treatment is performed while the cured resin composition has polymerization curing activity, the above-mentioned cationic heat is used. It should be understood that the polymerization initiator can be omitted.

(4) A paint having both ultraviolet curability and heat curability The type (4) paint contains a heat-curable component and a heat-curing catalyst in addition to the above-mentioned (2) paint component. Things are used.

The heat-curable component of the paint (4) may be a polar group capable of reacting with the functional group of the resin of the ultraviolet-curable component, such as a hydroxyl group or an epoxy group, such as a methylol group or an etherified methylol. A thermosetting resin having a group, an epoxy group and the like, particularly an amino resin, an epoxy resin and the like are used. Phenolic resins should not be used because they exhibit an inhibitory effect on ultraviolet curing.

As the amino resin, melamine-formaldehyde resin, benzoguanamine-formaldehyde resin, urea-formaldehyde resin and the like are used. These resins are desirably etherified with alcohols such as ethanol and butanol. This amino resin is obtained by reacting a corresponding nitrogen-containing compound with formaldehyde or a functional derivative thereof in the presence of an alkali metal catalyst or an alkaline earth metal catalyst, and, if necessary, etherifying it. The amino resin used is generally 3
It preferably has a number average molecular weight of 00 to 3000, especially 500 to 2000.

As the epoxy resin, a bisphenol-type epoxy resin obtained by polycondensation of a bisphenol such as bisphenol A or bisphenol F with epihalohydrin is preferable, and its epoxy equivalent is generally 40.
Those having a range of 0 to 20,000, especially 1,000 to 5,000, and a number average molecular weight of 1,000 to 20,000, especially 2,000 to 13,000 are preferred.

As the catalyst for heat curing, phosphoric acid and protonic acids represented by sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid and toluenesulfonic acid are used.

The type (4) primer preferably contains a thermosetting component in an amount of 10 to 50% by weight. On the other hand, the photo-radical initiator is suitably used in the paint in an amount of 0.5 to 10% by weight.

In this embodiment of the present invention, it is preferable that at least a part of the heat-curable component is an amino resin from the viewpoint of heat curability, and the amino resin is present in the coating material in an amount of 5 to 40% by weight. Is desirable. If the content of the amino resin is less than the above range, there is a tendency that a satisfactory coating film hardness is not obtained, while if it is more than the above range,
Workability of the coating film is reduced, and neck-in processing and flange processing tend to be difficult.

The primers (1) to (4) used in the present invention may contain a coating compound known per se, for example, a small amount of a solvent for improving the coatability, and a leveling for improving the smoothness of the coating film. An agent, a lubricant for imparting lubricity to a coating film, a pigment for improving the appearance of an undercoat, and the like can be contained according to a formulation known per se.

The ultraviolet curable primer used in the present invention
Generally, the viscosity is 1 sec. ^-1Has an apparent viscosity of 1
To 20 poise (p, 20 ° C).
No.

[Coating and Partial Curing] The UV curable primer can be applied to a curved body using a gravure roll, anilox roll, or a usual coating roll. The coating thickness of the primer is generally 1 to 15
It is preferably in the range of μm.

As the ultraviolet light used for the partial curing of the primer, a light having a wavelength of 220 to 420 nm, particularly 250 to 400 nm, including the near ultraviolet region, is generally used. As an ultraviolet light source, a metal halide lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, or the like is used.

The degree of partial curing of the primer is such that although the surface of the primer layer is still tacky, the flow of the primer layer is completely suppressed, and generally 5 to 25% of the amount of ultraviolet light required for complete curing. A degree of irradiation is sufficient. Since the thickness of the primer layer is extremely small, it is advantageous that the energy required for partial curing is considerably small, and an energy of 200 to 2000 Joules / m ² is generally sufficient.

[Transfer Sheet and Production Thereof] As shown in FIGS. 1 and 2, the transfer sheet used in the present invention is formed on a film substrate and directly or via a peelable coating layer on the film substrate.
The printed layer or the release coated layer is bonded to the film substrate in a state where the cellophane tape can be peeled off.

As the film substrate, a film substrate such as various plastic films, paper, metal foil, or a laminate thereof is used. In general, plastic films are suitable, for example, low density polyethylene, high density polyethylene, linear low density to ultra low density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene or ethylene, propylene, 1-butene, 4
Polyolefins such as random or block copolymers of α-olefins such as -methyl-1-pentene, ethylene / vinyl acetate copolymers, ethylene / vinyl alcohol copolymers, ethylene / vinyl chloride copolymers, etc. Styrene resins such as vinyl compound copolymer, polystyrene, acrylonitrile / styrene copolymer, ABS, α-methylstyrene / styrene copolymer, polyvinyl chloride, polyvinylidene chloride, vinyl chloride / vinylidene chloride copolymer, poly Polyvinyl compounds such as methyl acrylate and polymethyl methacrylate, nylon 6, nylon 6-6, nylon 6-10, nylon 11, nylon 1
Films made of thermoplastic polyesters such as polyamide 2, polyethylene terephthalate, polybutylene terephthalate, etc., polycarbonates, polyphenylene oxides, and the like, or mixtures thereof are preferably used.
These films are unstretched cast films,
Although a uniaxially or biaxially oriented stretched film may be used, a biaxially stretched film is particularly suitable in terms of dimensional stability. Among these films, an olefin resin or polyester film, particularly a biaxially stretched film, is suitable.

The film substrate should have strength enough to withstand various steps such as printing, transfer and peeling, and the thickness of the film substrate is generally in the range of about 10 to 50 μm. Is appropriate.

The surface of the film substrate can be wetted without causing repelling of the printing ink or the releasable paint, and the cellophane tape can be released from the cured ink layer or the releasable coating film. . No special treatment is required if wetting with printing ink or releasable paint is possible, but in the case of plastic film, chemical treatment with sulfuric acid-chromic acid mixed acid or caustic soda, flame treatment, corona discharge treatment, plasma Surface treatment such as treatment is suitable for improving wettability. Generally, a minimum surface treatment is preferred as long as the wetting tension is at least 44 dyne / cm.

As the printing ink, an ultraviolet curable ink or a heat curable ink can be used. The ultraviolet-curable ink is obtained by using the ultraviolet-curable resin described in the section of the primer as a vehicle, and dispersing a colorant, an auxiliary agent for the ink, and the like in the vehicle.

On the other hand, the heat-curable ink is a heat-curable resin in which a coloring agent, an auxiliary agent for ink, and the like are dispersed in a vehicle of the heat-curable resin, and the resin for the ink is phenol resin, alkyd resin, polyester resin, or the like. Xylene resin, urea resin, melamine resin, thermosetting acrylic resin,
One type or a combination of two or more types such as an epoxy resin is exemplified. Among them, an ink using an alkyd type or polyester type vehicle is preferable. The alkyd type or polyester type vehicle comprises (i) a polyhydric alcohol such as glycerin, pentaerythritol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, sorbitol, mannitol, trimethylolpropane, and (ii) Polybasic acids such as phthalic anhydride, isophthalic acid, maleic acid, fumaric acid, sebacic acid, adipic acid, citric acid, tartaric acid, malic acid, diphenic acid,
1,8-naphthalylic acid, terpene oil, and at least one of rosin are polycondensed, and if necessary, this is (iii) a fatty oil or a fatty acid such as linseed oil, soybean oil, perilla oil, fish oil, tung oil, sunflower. Oil, walnut oil, deer oil, castor oil, dehydrated castor oil, distilled fatty acid, cottonseed oil, coconut oil, or a resin modified with these fatty acids or monoglycerides of fatty acids, and further modified with rosin and non-drying fatty acids It is also used in the form of urea melamine resin modification, drying oil fatty acid modification, phenolic resin modification, maleic acid resin modification, ester rosin modification, and other natural resin modifications. As the curing agent, metal soaps of various metals such as lead, cobalt, zinc, manganese and the like, naphthenates and the like are used.

The viscosity of the ink used in the present invention is generally 1 to 100 poise (p, 20 ° C.) at a shear rate of 1 sec ^−1.
It is desirable to be within the range.

Suitable examples of the color pigment are as follows. Black pigments Carbon black, acetylene black, run black, aniline black. Yellow pigment zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S, Hansa yellow G,
Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake. Orange pigments Red mouth lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, induslen brilliant orange RK, benzidine orange G, induslen brilliant orange GK. Red pigment Bengala, cadmium red, lead red, cadmium mercury sulfide, permanent red 4R, lithol red, pyrazolone red, watching red calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake, brilliant carmine 3B. Purple pigment Manganese purple, fast violet B, methyl violet lake. Blue pigment Navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, fast sky blue, indaslen blue B
C. Green pigment chrome green, chromium oxide, pigment green B,
Malachite Green Lake, Fanal Yellow Green G. White pigment Zinc white, titanium oxide, antimony white, zinc sulfide. Extender barite powder, barium carbonate, clay, silica, white carbon, talc, alumina white. As these pigments, it is preferable to use flash pigments from the viewpoint of dispersibility.

Examples of the compounding agents for ink include silicone oil and the like as antifoaming agents, and fluorine surfactants, silicone surfactants and acrylic copolymers as leveling agents.
Thickeners, thinners and the like can be used.

The release coating layer optionally provided as a base for the printing ink gives releasability to the film substrate and also serves as a clear lacquer layer for protecting the printing layer after transfer is completed.

The release coating layer may be of an ultraviolet curable type or a heat curable type. As the UV-curable resin composition, the UV-curable resin composition already described in the section of the primer and having excellent internal transparency is used.
On the other hand, as the heat-curable resin composition, a heat-curable resin composition having excellent internal transparency described in the section of the printing ink is used. Epoxy-acrylic resin, amino-acrylic resin and the like are particularly excellent as a peelable coating layer. Generally, it is preferable that the peelable coating layer is provided with a thickness of 1 to 15 μm.

The release coating layer can be formed using a coating apparatus known per se such as a roller coater, a doctor coater, an air knife coater, a bar coater and the like. A printing method known per se, such as printing, gravure printing, screen printing, or flexographic printing, can be used.

For the ultraviolet curing of the release coating layer and the printing ink layer, the same ultraviolet light source as that used for the partial curing of the primer is used, and these layers are substantially completely cured. The energy required for curing varies depending on the type of resin, but is generally 500 to 5000 joules / m ^2.
Energy such as is sufficient.

On the other hand, a heat source such as infrared rays is used for heat curing of the peelable coating layer and the printing ink layer, and these layers are heated to completely cure the peelable coating layer or the ink layer. The heating temperature varies depending on the resin composition and the type of catalyst, but is generally 180 to 220 ° C., particularly 190 to 220 ° C.
A range of 10 ° C. is preferred. The heating time varies depending on the temperature, but is preferably about 0.5 to 2 minutes. This heating can be performed by a hot air heating furnace, an infrared heating furnace, or the like.

[Transfer and Post-Curing] In the present invention, a transfer sheet and a curved body having an adhesive coating are overlapped so that the printing layer and the adhesive coating face each other, and a transfer pressure is applied between the two. Thereby, the printing layer or the releasable coating layer is transferred to the surface of the curved body.

For applying the transfer pressure, a roller, in particular, an elastic roller can be used. The transfer pressure is not particularly limited, but generally a linear pressure of about 5 to 30 kg / cm is appropriate.

The adhesive film after the transfer can be cured by ultraviolet irradiation or by heating. In the case of ultraviolet irradiation, it is sufficient to irradiate the remaining amount of ultraviolet light that reaches complete curing.
Heating may be performed at a temperature of 80 to 220 ° C. for about 0.5 to 2 minutes.

When the present invention is applied to a seamless can, the seamless can after the coating and partial curing, the printing layer transfer, and the post-curing is subjected to neck-in processing and flange processing to obtain a final can for cans. The neck-in processing can be performed in one or more stages by a known neck-in processing method, for example, a die method or a spin neck-in method.
The opening end of the neck-in cup is engaged with a flanging die to perform flanging, thereby forming a flange for double-tightening the can end.

[0125]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but it is needless to say that the present invention is not limited to the following examples.

[Preparation of Printing Ink] An ultraviolet curable ink was prepared by mixing, stirring, and mixing a resin, a pigment, and additives in the following parts by weight. 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate 60 parts 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene 10 parts 3-ethyl-3-hydroxymethyloxetane 15 parts Novolak type phenolic resin 5 parts Leafing type aluminum paste (solid content 65%) 5 parts UVI-6990 (photoinitiator Union Carbide Corporation) 5 parts

[Preparation of release primer] A release primer was prepared by blending a resin and additives in the following parts by weight, stirring and mixing. 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate 65 parts 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene 10 parts 3-ethyl-3-hydroxymethyloxetane 10 parts Novolak type epoxy resin 10 parts UVI-6990 (photoinitiator Union Carbide Corporation) 5 parts

[Preparation of Adhesive Primer] A resin and an additive were blended in the following parts by weight, and stirred and mixed to prepare an adhesive primer. [Adhesive primer A] 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate 38 parts Bis- (3,4-epoxycyclohexyl) adipate 30 parts Epoxidized polybutadiene 10 parts Hydroxybutyl vinyl ether 10 parts Limonenedioxide 10 parts UVI-6990 (photoinitiator Union Carbide Corporation) 2 parts

[Adhesive Primer B] Acrylic resin 20 parts Amino resin 10 parts 2-propenoic acid, 1,6-hexanediol bis [oxy (2-hydroxy-3,1-propanediol) ester] 20 parts Nonylphenol EO modified (N = 4) Acrylate 15 parts 2-hydroxy-3-phenoxypropyl acrylate 30 parts 1-hydroxy-cyclohexyl-phenyl-ketone 4 parts Acid catalyst 1 part

[Production of Thinned Seamless Cans]
Biaxial stretching with a thickness of 20 μm on the inner side of a can of 18 mm, tempered DR-9 tin-free steel plate (metallic chromium content 120 mg / m ² , chromium oxide content 15 mg / m ² as surface treatment coating amount) A polyethylene terephthalate / isophthalate copolymer film and a 15 μm-thick biaxially stretched polyethylene terephthalate / isophthalate copolymer film containing 20% by weight of titanium oxide on the outer side of the can are simultaneously heated on both sides at the melting point of the film. The organic coated metal plate was obtained by adhering and immediately cooling with water.
After the grammar wax was uniformly applied to the organic coated metal plate, it was punched into a circular plate having a diameter of 160 mm to form a shallow drawn cup according to a conventional method. The drawing ratio in this drawing step is 1.59. Next, primary and secondary redrawing processes were performed to obtain a thinned deep drawing cup. The molding conditions in the redrawing step and various characteristics of the redrawn deep drawn cup are shown below. Primary redrawing ratio 1.23 Secondary redrawing ratio 1.24 Redrawing die action corner radius of curvature 0.30 mm Redrawing die holding corner radius of curvature 1.0 mm Cup diameter 66 mm Cup height 130 mm Side wall thickness Rate of change: -40% After that, after performing doming molding according to a conventional method, the deep drawing cup was heat-treated at 215 ° C for 1 minute to remove processing distortion of the film and volatilize the lubricant. Next, the opening end was trimmed to obtain a resin-coated thin seamless can having a height of 123 mm.

Example 1 An image was formed by flexographic printing on a 12 μm-thick biaxially stretched polyethylene terephthalate film using the ultraviolet-curable ink. Then, 500 m using a metal halide lamp for the ink layer
The transfer printing film was obtained by irradiating ultraviolet rays of J / cm ² to cure the ink layer. Next, when the ink layer was subjected to a cellophane peel test, the ink layer was easily peeled from the film substrate. Subsequently, the can body portion of the thinned seamless can was coated with an adhesive primer A at a thickness of 3 μm, and while rotating the can in the circumferential direction of the can, the metal was passed under an ultraviolet irradiation device provided with a plurality of metal halide lamps,
The film was irradiated with 50 mJ / cm ² of ultraviolet light to exhibit adhesiveness. The printing film was pressed against the can body of the can so that the ink layer and the adhesive primer layer faced each other. At this time, care was taken to prevent dust and air from entering between the film and the can. Next, when the film pressed against the thinned seamless can was peeled off, the image on the film was transferred to the can body side, and a printed image was formed on the can body. The image on the can was different from a commercially available two-piece can which was subjected to curved surface printing according to a conventional method, and had excellent appearance characteristics without overlap. An ultraviolet irradiation device in which a plurality of metal halide lamps are installed while applying a 3 μm-thick cationically curable UV-curable finishing varnish to the body of a thinned seamless can after transfer printing and rotating the can in the circumferential direction of the can. The finished varnish was cured by passing it under the bottom and irradiating it with ultraviolet rays of 100 mJ / cm ² . Then, the can was heat-treated in an oven at 200 ° C. for 1 minute to cure the adhesive primer and obtain a desired printed material.

Example 2 The above-mentioned release primer was applied to a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm, and 100 mJ was applied using a metal halide lamp.
/ Cm ² was applied to cure the release primer layer. Next, after forming an image with the ultraviolet curable ink on the release primer layer by flexographic printing, the ink layer was formed for 500 m using a metal halide lamp.
The transfer printing film was obtained by irradiating ultraviolet rays of J / cm ² to cure the ink layer. Next, when a cellophane tape peeling test was performed, the ink layer was easily peeled from the film substrate together with the peeling primer layer. Subsequently, the can body portion of the thinned seamless can was coated with an adhesive primer A at a thickness of 3 μm, and while rotating the can in the circumferential direction of the can, the metal was passed under an ultraviolet irradiation device provided with a plurality of metal halide lamps, The film was irradiated with 50 mJ / cm ² of ultraviolet light to exhibit adhesiveness. The printing film was pressed against the can body of the can so that the ink layer and the adhesive primer layer faced each other. At this time, care was taken to prevent dust and air from entering between the film and the can. Next, when the film pressed against the thinned seamless can was peeled off, the image on the film was transferred to the can body side for each release primer layer, and a printed image was formed on the can body. The image on the can is different from a commercially available two-piece can that has been subjected to curved printing in accordance with the usual
It was excellent in appearance characteristics without overlap. Apply a thermosetting water-based finishing varnish to the can body of the thinned seamless can after transfer printing so that the thickness of the dried coating film becomes 3 μm, and heat-treat it at 200 ° C. for 1 minute in an oven to adhere to the finishing varnish. The hardened primer layer was cured to obtain a target print.

Example 3 An image was formed by flexographic printing on a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm using the ultraviolet-curable ink. Then, 500 m using a metal halide lamp for the ink layer
The transfer printing film was obtained by irradiating ultraviolet rays of J / cm ² to cure the ink layer. Next, when the ink layer was subjected to a cellophane peel test, the ink layer was easily peeled from the film substrate. Subsequently, the can body of the thinned seamless can is coated with an adhesive primer B at a thickness of 3 μm, and while rotating the can in the circumferential direction of the can, it is passed under an ultraviolet irradiation device provided with a plurality of metal halide lamps,
The film was irradiated with 50 mJ / cm ² of ultraviolet light to exhibit adhesiveness. The printing film was pressed against the can body of the can so that the ink layer and the adhesive primer layer faced each other. At this time, care was taken to prevent dust and air from entering between the film and the can. Next, when the film pressed against the thinned seamless can was peeled off, the image on the film was transferred to the can body side, and a printed image was formed on the can body. The image on the can was different from a commercially available two-piece can which was subjected to curved surface printing according to a conventional method, and had excellent appearance characteristics without overlap. A thermosetting water-based finishing varnish is applied to the can body of the thinned seamless can after transfer printing so that the dry film thickness becomes 3 μm, and is heat-treated at 200 ° C. for 1 minute in an oven to apply the finishing varnish and the adhesive primer. The cured product was obtained by curing.

[Comparative Example 1] Corona-treated thickness 12
An image was formed on the biaxially stretched polyethylene terephthalate film of μm by gravure printing with a polyurethane-based packaging film ink, and the solvent was evaporated by heat treatment. Next, a cellophane tape peeling test of the ink layer was performed, but no ink layer was peeled off from the film substrate.
Subsequently, an adhesive primer was applied with a thickness of 3 μm on the can body of the thinned seamless can, and while the can was rotated in the circumferential direction of the can, the metal was passed under an ultraviolet irradiation device provided with a plurality of metal halide lamps. / Cm ² to irradiate ultraviolet light to develop adhesiveness. The printing film was pressed against the can body of the can so that the ink layer and the adhesive primer layer faced each other. At this time, care was taken to prevent dust and air from entering between the film and the can. Next, the film pressed against the thinned seamless can was peeled off, but since the ink layer was firmly fixed to the film substrate,
The image on the film could not be transferred to the can body.

As described in Examples and Comparative Examples above, a print layer that can be peeled off from a film substrate by a cellophane tape is provided, and the print layer is coated with an adhesive primer that develops tackiness when irradiated with ultraviolet light. It is a feature of the present invention to peel off from a substrate and transfer it to a printing substrate, and the manufacturing method having this feature is not limited by the present embodiment. According to the present invention, as shown in the examples, it is apparent that a print screen excellent in appearance without overlapping or underlap peculiar to curved surface printing can be formed on a printing medium.

[0136]

According to the printing method of the present invention, printing and transfer in a planar state can be performed by providing a printing layer in a peelable state directly or via a cured primer layer on a film substrate such as a plastic film. This makes it possible to eliminate restrictions on curved surface printing, so that it is possible to perform fine printing composed of a collection of halftone dots such as gravure printing. Further, in the printing method of the present invention, an ultraviolet-curable primer is applied to the surface of the curved body, and is irradiated with ultraviolet rays to form an adhesive film. It is possible to transfer the printing layer to the surface of the curved body by pressing the printing layer and the adhesive film while facing each other and peeling the film substrate. Further, by hardening the adhesive film after the transfer of the printing layer by ultraviolet irradiation or heating, the printing layer having the above-mentioned characteristics can be firmly bonded to the curved body. Moreover,
The curved printed body according to the present invention has a novel feature not found in the conventional curved printed body. That is, in the conventional curved printing body, even if there is a slight error in the circumference of the can body to be printed, there is an overlap in which the printing layers are overlapped so that a missing portion of the printing does not occur. However, in the curved printed body of the present invention, even if there is a seam in the print layer, the seam is formed by abutting the print layers with each other. Does not exist at all and has excellent appearance characteristics.

[Brief description of the drawings]

FIG. 1 is a process chart for explaining an example of a printing method of the present invention.

FIG. 2 is a process chart for explaining another example of the printing method of the present invention.

FIG. 3 is an enlarged cross-sectional view showing a seam of a printing layer between a conventional curved printed body and the curved printed body of the present invention.

FIG. 4 is a graph plotting the relationship between the amount of coating film (wet) per can and the amount of generated mist for a base paint (white coating) having a solid content of 40% while changing the coating speed.

FIG. 5 is a graph showing 1%
It is the graph which plotted similarly the relationship between the coating film amount (wet) per can and the generated mist amount while changing the coating speed.

FIG. 6 is a side view showing an ultraviolet-curable primer coating step, an ultraviolet-curing step, a transfer step, and a final curing step in the printing method of the present invention.

FIG. 7 is a sectional view showing an example of a sectional structure of a two-piece can.

FIG. 8 is a sectional view showing another example of the sectional structure of the two-piece can.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film base 2 Printing layer 3 Can body 4 Adhesive film 5 Clear paint 6 Coating layer 10 Transfer sheet 11 Turret for primer coating 12 Turret for curing 13 Print image transfer part 14 Turret for final curing 15 Two-piece can 15a, 15b, 15c Cup 16 Primer coating unit 19 Transfer sheet 30 Cup 31 Metal substrate 32, 32a Inner organic coating 34 Outer organic coating

Claims (8)

[Claims] 1. An ink is printed on a membrane substrate and cured,
A step of forming a transfer sheet having a print layer that is releasable with cellophane tape, a step of applying an ultraviolet-curable primer to the surface of the curved body, and irradiating ultraviolet rays to form an adhesive film; Transferring the printing layer to the surface of the curved body with the coating facing the surface of the curved body. 2. A step of applying and curing a primer on a film substrate to form a coating layer that is releasable from cellophane tape, and further printing and curing ink on the coating layer to have a printing layer. A step of forming a transfer sheet, a step of applying an ultraviolet-curable primer to the surface of the curved body, irradiating ultraviolet rays to form an adhesive film, and a step of facing the print layer and the adhesive film with the print layer. Transferring the release layer to the surface of the curved body. 3. The transfer method according to claim 1, wherein the adhesive coating is cured by ultraviolet irradiation or heat treatment after the transfer step. 4. The printing method according to claim 1, wherein after the transfer step, a clear coating is applied on the printing layer, and the clear coating is cured together with the adhesive coating by ultraviolet light or heat treatment. 5. The printing method according to claim 1, wherein the ink is an ultraviolet curable ink having a curing shrinkage property. 6. The printing method according to claim 2, wherein the easily peelable primer is an ultraviolet-curable resin having a curing shrinkage property. 7. The printing method according to claim 1, wherein the film substrate is a polyester or polyolefin film. 8. A curved body, an ultraviolet-curable primer layer applied to the surface of the curved body, and a printing ink layer applied by transfer to the primer layer, wherein the printing ink layer substantially has an overlap portion. A curved surface printed body characterized by having no upper surface.