JP5878005B2 - Printed polyester film and printed polyester film coated can - Google Patents

Description

  The present invention relates to a printed polyester film-coated metal can having a protective coating layer made of the printed polyester film on the printed polyester film and the outer surface of the can body.

  Conventionally, a protective coating layer made of a printed polyester film is provided on the outer surface side of a can body of a metal can used for containers such as beverages, and images such as a predetermined display and design are provided on the metal can by using the printed polyester film. A cosmetic property is imparted by this method.

  As the printed polyester film, for example, there is one provided with a hologram pattern having a fine uneven shape in an embossed shape or a relief shape on the outer surface. According to such a printed polyester film, the hologram pattern can be visually recognized when the protective coating layer is formed on the outer surface side of the can body of the metal can body, and a special cosmetic property can be imparted. .

  However, in the printed polyester film having the hologram pattern on the outer surface, when the protective coating layer is formed on the outer surface side of the can body portion of the metal can body, moisture is condensed on the can body portion or the consumer If sebum or sweat from the hand when the can body is gripped adheres to fill the uneven shape, there is a problem that the hologram pattern may not be visible.

  In order to solve the above problem, the hologram pattern is provided on one surface of a polyester film serving as a substrate, an aluminum vapor deposition layer is provided on the hologram pattern, and an adhesive layer provided on the aluminum vapor deposition layer is further interposed. There has been proposed a printed polyester film that is adhered to the outer surface of the metal can body. In the printed polyester film, a printing layer is provided between the polyester film serving as the substrate and the hologram pattern, or on the surface opposite to the hologram pattern of the polyester film serving as the substrate (see, for example, Patent Document 1). .

  According to the printed polyester film, a light beam that has passed through the polyester film serving as the base and the printed layer and entered the hologram pattern is reflected or refracted by the aluminum vapor deposition layer, so that the hologram pattern is visually recognized. be able to.

Republished patent WO2009 / 013883

  However, in the conventional printed polyester film, when the protective coating layer is formed on the outer surface side of the can body of the metal can body, the aluminum vapor deposition layer deteriorates when the metal can body undergoes retort treatment, and the hologram pattern is formed. There is an inconvenience that it cannot be visually recognized.

  The present invention eliminates such inconvenience, and when a protective coating layer is formed on the outer surface side of the can body of the metal can body, the hologram pattern cannot be visually recognized even if the metal can body is subjected to retort processing. An object of the present invention is to provide a printed polyester film without any problems.

  Another object of the present invention is to provide a printed polyester film-coated metal can having a protective coating layer made of the printed polyester film on the outer surface of the can body.

In order to achieve such an object, the present invention provides a protective coating layer that is heat-bonded to the outer surface side of a can body portion of a metal plate for a can body material or a bottomed cylindrical can body via a thermosetting resin adhesive layer. The printed polyester film is provided with a hologram pattern layer having unevenness having a height difference of 0.1 to 2.0 μm on one surface of a polyester film serving as a base, and the hologram First printing comprising a resin composition comprising an epoxy butyral resin and a polyisocyanate resin, or a resin composition comprising a polyester polyurethane resin and a polyisocyanate resin, comprising an aluminum thin film piece in a part on the pattern layer A resin composition comprising an epoxy butyral resin and a polyisocyanate resin. , A resin composition comprising a polyester polyurethane resin and a polyisocyanate resin, a second printing layer having a display and an image by the pigment, heat printing layer of the first and second printing layer A curable resin adhesive layer is provided .

  In the printed polyester film of the present invention, the hologram pattern layer is provided on one surface of a polyester film serving as a substrate, and the thermosetting resin adhesive layer is provided on the hologram pattern layer via the print layer. ing. Therefore, the printed polyester film of the present invention was heat-bonded to the outer surface side of the can body of the metal plate for can body material or the bottomed cylindrical can body by the thermosetting resin adhesive layer to form a protective coating layer. Sometimes, the hologram pattern layer is disposed between the polyester film serving as the substrate and the printing layer. Accordingly, the hologram pattern layer is protected by the polyester film serving as the base, and moisture is condensed on the can body part, or sebum and sweat on the hand when the consumer holds the can body part adheres. This can prevent the unevenness from being buried.

  The printed polyester film is transparent to the polyester film serving as the base when the protective coating layer is formed by heat bonding to the outer surface of the can body portion of the metal plate for can body material or the bottomed cylindrical can body. Then, the light beam incident on the hologram pattern is reflected or refracted by the aluminum thin film piece included in the printing layer. As a result, according to the printed polyester film, the hologram pattern can be visually recognized.

  At this time, the printing layer is formed of a resin composition composed of an epoxy butyral resin and a polyisocyanate resin or a resin composition composed of a polyester polyurethane resin and a polyisocyanate resin. All of the resin compositions have resistance to retort treatment, and even when subjected to the retort treatment, moisture can be prevented from penetrating into the resin composition.

  In the printed polyester film of this invention, since the said aluminum thin film piece is contained in the said resin composition, even if it receives the said retort process, it will be protected by this resin composition and will not deteriorate. Therefore, according to the printed polyester film of the present invention, when the protective coating layer is formed on the outer surface side of the can body portion of the metal plate for can body material or the bottomed cylindrical can body, the metal can body is subjected to retort treatment. However, it can be prevented that the hologram pattern cannot be visually recognized.

In the portion where previous SL first printed layer is provided, we are possible to clearly visually recognize the holographic pattern. Further, in the portion where the second printed layer is provided, the hologram pattern can be slightly visually recognized, and images of a predetermined display and design can be clearly visually recognized.

  In the printed polyester film of the present invention, the aluminum thin film piece may be obtained by peeling and pulverizing an aluminum deposited film deposited on a support from the support. Moreover, it is preferable that the said aluminum thin film piece exists in the range whose average thickness is 0.01-0.5 micrometer, and the magnitude | size of a surface direction is the range which averages 5-25 micrometers.

When the aluminum thin film piece included in the first printed layer has an average thickness of less than 0.01 μm and an average size in a plane direction of less than 5 μm, the aluminum thin film piece transmits the polyester film serving as the substrate and transmits the hologram. The light incident on the pattern may not be sufficiently reflected or refracted. Further, the aluminum thin film pieces included in the first printed layer have a thickness exceeding 0.5 μm on the average and a plane direction size exceeding 25 μm on the average, the light beam incident on the hologram pattern is directed in a preferable direction. It may not be possible to reflect or refract. Therefore, it is further preferable that the aluminum thin film pieces included in the first printed layer have an average thickness in the range and an average size in the plane direction of 10 μm.

Further, in the printing polyester film of the present invention, the thin aluminum film pieces included in the first print layer comprises in the range of 40 to 80% by weight relative to the total amount of the resin composition of the first printed layer It is preferable. Wherein the amount is less than 40% by weight relative to the content of the first said aluminum thin film pieces included in the print layer of the total amount of the resin composition of the first printed layer, transmitted through the polyester film serving as the base In some cases, the light beam incident on the hologram pattern cannot be sufficiently reflected or refracted. When the content of the aluminum thin film pieces included in the first printing layer is more than 80 wt% relative to the total amount of the resin composition of the first printed layer, cans by printing polyester film of the present invention When the metal can body in which the protective coating layer is formed on the outer surface side of the trunk portion is subjected to the retort treatment, the resin composition including the aluminum thin film piece may be peeled off.

In addition, the printed polyester film-coated metal can body of the present invention is an uneven surface having a height difference of 0.1 to 2.0 μm on one surface of the polyester film serving as a base relative to the outer surface side of the can body portion of the metal can body. comprising a hologram pattern layer comprising comprises a thin aluminum film piece to a portion on the hologram pattern layer, the resin composition composed of an epoxy butyral resin and a polyisocyanate resin or from a polyester polyurethane resin and a polyisocyanate resin A resin composition composed of an epoxy butyral resin and a polyisocyanate resin, or a polyester polyurethane resin and a polyisocyanate resin. A resin composition comprising a display and an image by the pigment. Comprising a printing layer, the printing polyester film with a thermosetting resin-based adhesive layer on the first printed layer and the second printing layer is, more heat contact bonding through a thermosetting resin adhesive layer characterized in that it comprises the formed protective coating layer.

  According to the printed polyester film-coated metal can of the present invention, by providing the protective coating layer made of the printed polyester film, it is possible to prevent the hologram pattern from being visually recognized even when subjected to a retort treatment. Can do.

  In the printed polyester film-coated metal can body of the present invention, the metal can body may be a welded can body formed by welding both ends of a strip-shaped metal plate for a can body material. A bottomed cylindrical can body obtained by drawing or ironing a metal plate for material may be used. The welded can can be formed into a so-called three-piece can by double-tightening can lids at both ends. The bottomed cylindrical can can be formed into a so-called two-piece can by double-tightening a can lid on the open end.

Explanatory sectional drawing which shows the structural example of the printing polyester film which concerns on this invention. Explanatory sectional drawing which shows the structure of the metal plate for can body materials in which the protective coating layer which consists of a printing polyester film shown in FIG. 1 was formed. Explanatory sectional drawing which shows the structure of the principal part of the can body part of the welding can body which concerns on this invention. Explanatory sectional drawing which shows the structure of the bottomed cylindrical can which concerns on this invention.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

  The printed polyester film 1 of this embodiment shown in FIG. 1 (a) is bonded to the outer surface side of the can body portion of a metal plate for can body material or a bottomed cylindrical can body to form a protective coating layer. The printed polyester film 1 includes a printed layer 4a or a pigment made of a resin composition including a hologram pattern layer 3 and an aluminum thin film provided on the hologram pattern layer 3 on one surface of a polyester film 2 serving as a base. The printing layer 4b which consists of a resin composition to contain, and the thermosetting resin type adhesive bond layer 5 provided on the printing layers 4a and 4b are provided. The printed polyester film 1 includes a cured overcoat layer 6 on the other surface (surface opposite to the hologram pattern layer 3) of the polyester film 2 serving as a base.

  The printed polyester film 1 of the present embodiment may be one in which a cured overcoat layer 6 is formed as desired after being bonded to the outer surface of the can body of a metal can body to form a protective coating layer. In this case, as shown in FIG. 1B, the printed polyester film 1 does not include the cured overcoat layer 6 on the surface opposite to the hologram pattern layer 3 of the polyester film 2 serving as a base.

  Next, as the polyester film 2 serving as a substrate, a polyester film obtained by polycondensation of a dicarboxylic acid component and a diol component and having excellent strength and transparency is suitable.

  Examples of the polyester used as the film material include polyesters obtained by polycondensation of aromatic dicarboxylic acids such as naphthalene dicarboxylic acid, terephthalic acid, and isophthalic acid with diols such as ethylene glycol, propylene glycol, and butylene glycol. Can be mentioned. The polyester is preferably a polyester (polyethylene naphthalate) obtained by polycondensation of naphthalenedicarboxylic acid and ethylene glycol or a polyester (polyethylene terephthalate) obtained by polycondensation of terephthalic acid and ethylene glycol.

  Further, the polyester film 2 is required to have strength for providing the printing layers 4a and 4b and dimensional stability against heat treatment when bonded to the metal plate for can body material.

  Therefore, the polyester film 2 is preferably a heat-resistant polyester film such as polyethylene naphthalate, a uniaxially or biaxially stretched polyethylene terephthalate film, or the like. In particular, the polyester film 2 is a biaxially stretched polyester film having a material physical property of 1.2% or less in the longitudinal direction and 0% in the width direction when held at 150 ° C. for 30 minutes. Preferably there is.

  Moreover, it is preferable that the polyester film 2 has the thickness of the range of 5-50 micrometers. When the thickness of the polyester film 2 is less than 5 μm, the polyester film 1 is damaged when a drawing process such as a neck-in process is performed on the can body portion of the metal can body on which the protective coating layer is formed by the printed polyester film 1. The effect of preventing the hologram pattern from becoming invisible due to easy attachment, pinholes, etc., and the effect of preventing corrosion of the can body and metal elution may not be sufficiently obtained. Further, when the thickness of the polyester film 2 exceeds 50 μm, the residual stress increases. When the can body portion of the metal can body is subjected to a drawing process such as a neck-in process, the metal for the can body material of the printed polyester film 1 is obtained. There exists a tendency for the adhesiveness with respect to a board to fall.

  Next, the hologram pattern layer 3 is made of, for example, an ultraviolet curable resin, and a hologram pattern 7 having unevenness having a height difference of 0.1 to 2.0 μm is formed on the surface opposite to the polyester film 2. The hologram pattern 7 is formed by pressing a press stamper on which a hologram pattern having a desired design is formed on an uncured ultraviolet curable resin, transferring the hologram pattern of the press stamper to the ultraviolet curable resin, It can be formed by irradiating and curing with ultraviolet rays.

  The hologram pattern layer 3 may be made of an electron beam curable resin or a thermosetting resin instead of the ultraviolet curable resin. In this case, after the hologram pattern is transferred by pressing the press stamper, the electron beam The resin can be cured by irradiating or heating.

  Next, the printing layer 4a includes an aluminum thin film piece, and is composed of a resin composition composed of an epoxy butyral resin and a polyisocyanate resin, or a resin composition composed of a polyester polyurethane resin and a polyisocyanate resin, For example, it is formed by gravure printing etc. on one side of polyester film 2 used. As the aluminum thin film piece, for example, an aluminum deposited film deposited on a support can be peeled off from the support and pulverized, and the thickness is in the range of 0.01 to 0.5 μm on average. The average size in the plane direction is preferably in the range of 5 to 25 μm, and the average size in the plane direction is more preferably 10 μm. Moreover, it is preferable that the said aluminum thin film piece contained in the printing layer 4a is contained in 40-80 mass% with respect to the whole quantity of the said resin composition.

  The print layer 4 a may be provided on at least a part of the hologram pattern layer 3, but may be provided on the entire surface of the hologram pattern layer 3. When the print layer 4 a is provided on a part of the hologram pattern layer 3, the print layer 4 b is provided on the other part of the hologram pattern layer 3.

  The printing layer 4b includes a conventionally known pigment, and is composed of a resin composition composed of an epoxy butyral resin and a polyisocyanate resin, or a resin composition composed of a polyester polyurethane resin and a polyisocyanate resin, and serves as a substrate. For example, it is formed on one surface of the polyester film 2 by gravure printing or the like.

  In order to make the printed image / design clear, a white ink layer may be provided by printing the entire surface of the white ink between the thermosetting resin adhesive layer 5 and the printing layers 4a and 4b. . As the white ink layer, a known layer called a so-called white presser can be used.

  Next, the thermosetting resin-based adhesive layer 5 includes a resin composition including an epoxy resin and an acid anhydride-based curing agent, a resin composition including a polyester resin and an aminoplast resin, or a polyester resin and a blocked isocyanate compound. It can form from the resin composition containing this.

  Next, the cured overcoat layer 6 is made of a thermosetting resin and is formed on the surface of the polyester film 2 opposite to the hologram pattern layer 3. The thermosetting resin is preferably a resin that forms a coating cured layer at a high temperature in a short time. For example, the thermosetting resin is composed of an epoxy resin and an aminoplast resin, and an organic acid or phosphoric acid, polyphosphoric acid, or the like as a short-time curing catalyst. The thing to which the inorganic acid of this is added is preferable. The thermosetting resin is preferably added with silicon or wax in order to improve the scratch resistance and the slipperiness of the cured overcoat layer 6.

  Next, the manufacturing method of the printed polyester film 1 of this embodiment is demonstrated.

  First, a heat treatment is performed on the polyester film 2 that is cut into a predetermined length by cutting the raw film every predetermined width to relieve the residual stress. Next, one surface of the polyester film 2 is coated with, for example, an ultraviolet curable resin, the hologram stamp 7 is transferred to the uncured ultraviolet curable resin by pressing the press stamper, and then irradiated with ultraviolet rays. The hologram pattern layer 3 is formed by curing the curable resin.

  Next, the printing layer 4a or the printing layer 4b is formed on the hologram pattern layer 3 by, for example, gravure printing, and the cured overcoat layer 6 is formed on the surface of the polyester film 2 opposite to the printing layers 4a and 4b.

  Next, the printed polyester film 1 is obtained by forming the thermosetting resin adhesive layer 5 on the printing layer 4a or the printing layer 4b.

  Next, the printed polyester film-covered metal can of this embodiment using the printed polyester film 1 will be described.

  When the printed polyester film-coated metal can body of the present embodiment is a welded can body, first, the metal plate 11 for can body material shown in FIG. 2 is formed. The metal plate 11 for can body material has the printed polyester film 1 shown in FIG. 1 interposed through the thermosetting resin-based adhesive layer 5 on the portion excluding both side edge portions 11a and 11a on the side that becomes the outer surface of the can. The protective coating layer 12 is formed by heat bonding. In FIG. 2, the polyester film 1 is shown with the hologram pattern layer 3, the printing layers 4a and 4b, and the overcoat layer 6 omitted.

  Moreover, the transparent polyester film 13 is the thermosetting resin adhesive similar to the printed polyester film 1 in the part except the both side edge parts 11a and 11a of the side used as the inner surface of the metal plate 11 for can body materials. The inner surface protective coating layer 15 is formed by heat bonding via the layer 14.

  As the metal plate 11 for can body material, island-shaped tin-plated steel plate (TNS plate), thin tin-plated steel plate (LTS plate), tin-free steel plate (TFS plate), aluminum plate, and various surface treatments are applied to the surfaces thereof. The surface-treated metal plate etc. which were made can be mentioned.

  The metal plate 11 for can body material on which the protective coating layer 12 and the inner surface protective coating layer 15 are formed is rolled as shown by an arrow in FIG. 2, and both side edge portions 11a and 11a are overlapped as shown in FIG. The can body 16 is formed by welding to form a welded can body. The portion of the can body portion 16 where the protective coating layer 12 and the inner surface protective coating layer 15 are not formed is covered with a known coating correction coating 17. And after carrying out neck-in process and the flange process of the both-ends edge part of the can trunk | drum 16, a 3 piece can body can be formed by carrying out double winding of the can lid separately manufactured at both ends.

  Next, when the printed polyester film-coated metal can body of the present embodiment is a bottomed cylindrical can body, first, the can body in which the polyester films 21 and 22 are bonded to both the front and back surfaces as shown in FIG. The bottomed cylindrical can 24 is formed by drawing or ironing the metal plate 23 for material. As the metal plate 23 for the can body material, a tin-free steel plate, an aluminum plate, a surface-treated metal plate having various surface treatments applied thereto, and the like can be used.

  Next, as shown in FIG. 4B, the printed polyester film 1 is thermally bonded to the can body portion of the bottomed cylindrical can body 24 via a thermosetting resin adhesive layer 4 (not shown). Thus, the protective coating layer 25 is formed. Then, after the neck-in process 26 and the flange process 27 are performed on the open end, a two-piece can body can be formed by double-tightening a separately manufactured can lid.

  The metal plate 23 for can body material may be one in which the polyester films 21 and 22 are not bonded to both the front and back surfaces.

  According to the printed polyester film 1 of the present embodiment, when the protective coating layers 12 and 25 are formed on the outer surface side of the can body portion of the metal can body, the cured overcoat layer 6, the polyester film 2, the hologram pattern layer 3, The light beam that has passed through is incident on the hologram pattern 7. And the hologram pattern 7 can be visually recognized because the said light ray is reflected or refracted by the said aluminum thin film piece contained in the printing layer 4a.

  As a result, the hologram pattern 7 can be clearly visually recognized in the portion where the printing layer 4a is provided. Further, in the portion where the printing layer 4b is provided, the hologram pattern 7 can be slightly visually recognized, and images such as a predetermined display and design by the pigment can be clearly visually recognized.

  The printing layers 4a and 4b are made of a resin composition composed of an epoxy butyral resin and a polyisocyanate resin, or a resin composition composed of a polyester polyurethane resin and a polyisocyanate resin, and have retort resistance. Therefore, the metal can body in which the protective coating layers 12 and 25 are formed on the can body portion by the printed polyester film 1 of the present embodiment prevents moisture from penetrating into the resin composition even when subjected to a retort treatment. Therefore, it can prevent that the said aluminum thin film piece contained in the said printing layer 4a deteriorates.

  As a result, the metal can body in which the protective coating layers 12 and 25 are formed on the can body portion by the printed polyester film 1 of the present embodiment does not prevent the hologram pattern 7 from being visually recognized even when the retort treatment is performed.

  Furthermore, in the said metal can body in which the protective coating layers 12 and 25 were formed in the can body part by the printed polyester film 1 of this embodiment, the hologram pattern layer 3 is for the can body material which forms the polyester film 2 and the can body part. It will be arranged between the metal plates 11 and 23. Accordingly, the hologram pattern layer 3 is protected by the polyester film 2, and moisture is condensed on the can body part, or sebum and sweat on the hand when the consumer holds the can body part. Also, it is possible to prevent the hologram pattern 7 having the unevenness from being buried.

  Next, examples and comparative examples of the present invention are shown.

[Example 1]
In this example, first, as a polyester film 2 serving as a substrate, an ultraviolet curable resin serving as a hologram pattern layer 3 was applied to one surface of a polyethylene terephthalate film having a thickness of 12 μm. Next, after the ultraviolet curable resin is uncured, a press stamper on which a hologram pattern of a desired design is formed is pressed, and the hologram pattern of the press stamper is transferred to the ultraviolet curable resin. The film was cured by irradiating with ultraviolet rays. As a result, the hologram pattern layer 3 provided with the hologram pattern 7 provided with unevenness having a height difference of 0.1 to 2.0 μm was formed.

  Next, the printing layer 4a was formed in the predetermined part on the hologram pattern layer 3 by gravure printing. The printing layer 4a includes 60% by mass of an aluminum thin film piece in a resin composition composed of an epoxy butyral resin and a polyisocyanate resin with respect to the total amount of the resin composition. In this embodiment, the aluminum thin film piece is obtained by peeling and pulverizing an aluminum deposited film deposited on a support from the support, and having an average thickness of 0.5 μm and an average size in the plane direction. The thing of 25 micrometers was used.

  Next, the printing layer 4b was formed by gravure printing in the part in which the printing layer 4a on the hologram pattern layer 3 was not formed. The printing layer 4b includes a pigment in a resin composition composed of an epoxy butyral resin and a polyisocyanate resin, and forms an image such as a predetermined display and design.

  Next, a cured overcoat layer 6 was formed on the surface of the polyester film 2 opposite to the hologram pattern layer 3 using a thermosetting resin composition composed of an epoxy resin and an aminoplast resin.

  Next, a thermosetting resin-based adhesive layer 5 was formed on the printing layers 4 a and 4 b of the polyester film 2 to obtain a printing polyester film 1. The thermosetting resin-based adhesive layer 5 is composed of a polyester resin and a thermosetting resin-based adhesive composition containing 2% by mass of a blocked isophorone diisocyanate compound based on the total amount of the polyester resin, and is blocked immediately before use. It was formed by blending a non-isocyanate compound.

  Next, the printed polyester film 1 obtained in this example is a part excluding both side edge portions 11a and 11a on the side that becomes the outer surface of the can body material metal plate 11 made of an island-shaped tin-plated steel plate, The protective coating layer 12 was formed by heat bonding through the thermosetting resin adhesive layer 5.

  Next, the transparent polyester film 13 is the same as the thermosetting resin adhesive layer 5 on the portion excluding the side edge portions 11b, 11b on the side that becomes the inner surface of the can body material metal plate 11. The inner surface protective coating layer 15 was formed by heat bonding through a thermosetting resin adhesive layer 14 made of a resin composition.

  Next, the metal plate 11 for can body material on which the protective coating layer 12 and the inner surface protective coating layer 15 are formed is rolled as shown by an arrow in FIG. 2, and both side edge portions 11a and 11a are formed as shown in FIG. The can body 16 was formed by overlapping and welding to form a welded can body. The portion of the can body portion 16 where the protective coating layer 12 and the inner surface protective coating layer 15 are not formed was covered with a known coating correction coating 17. And after necking in and flange processing at both end edges of the can body 16, double-tightening the can lids separately manufactured at both ends, 3 pieces with a height of 103.9 mm and a diameter of 52.5 mm A can body was formed into a printed polyester film-coated metal can body of this example.

  Next, the printed polyester film-coated metal can obtained in this example was subjected to a retort treatment at 125 ° C. for 30 minutes. And it was confirmed whether the hologram pattern 7 was visually recognizable. The results are shown in Table 1.

[Example 2]
In this example, the printed polyester 4a was exactly the same as Example 1 except that the aluminum thin film pieces contained in the printed layer 4a had an average thickness of 0.5 μm and an average size in the plane direction of 5 μm. Film 1 was obtained.

  Next, except that the printed polyester film 1 obtained in this example was used, a three-piece can was formed in exactly the same manner as in Example 1 to obtain a printed polyester film-covered metal can of this example. .

  Next, the printed polyester film-coated metal can obtained in this example was subjected to a retort treatment in exactly the same manner as in Example 1. And it was confirmed whether the hologram pattern 7 was visually recognizable. The results are shown in Table 1.

Example 3
In this example, the printed polyester 4 is exactly the same as Example 1 except that the aluminum thin film pieces contained in the printed layer 4a have an average thickness of 0.01 μm and an average size in the plane direction of 5 μm. Film 1 was obtained.

  Next, except that the printed polyester film 1 obtained in this example was used, a three-piece can was formed in exactly the same manner as in Example 1 to obtain a printed polyester film-covered metal can of this example. .

  Next, the printed polyester film-coated metal can obtained in this example was subjected to a retort treatment in exactly the same manner as in Example 1. And it was confirmed whether the hologram pattern 7 was visually recognizable. The results are shown in Table 1.

[Reference Example 1]
In this reference example, the printed polyester 4 is exactly the same as in Example 1 except that the aluminum thin film pieces included in the printed layer 4a are those having an average thickness of 0.1 μm and a plane direction size of 50 μm on average. Film 1 was obtained.

  Next, except that the printed polyester film 1 obtained in this reference example was used, a 3-piece can body was formed in exactly the same manner as in Example 1, and a printed polyester film-coated metal can body of this reference example was obtained. .

  Next, the printed polyester film-coated metal can obtained in this example was subjected to a retort treatment in exactly the same manner as in Example 1. And it was confirmed whether the hologram pattern 7 was visually recognizable. The results are shown in Table 1.

[Reference Example 2]
In this reference example, the printing polyester 4a was exactly the same as in Example 1 except that the aluminum thin film pieces included in the printing layer 4a were those having an average thickness of 0.01 μm and an average size in the plane direction of 1 μm. Film 1 was obtained.

  Next, except that the printed polyester film 1 obtained in this reference example was used, a 3-piece can body was formed in exactly the same manner as in Example 1, and a printed polyester film-coated metal can body of this reference example was obtained. .

  Next, the printed polyester film-coated metal can obtained in this example was subjected to a retort treatment in exactly the same manner as in Example 1. And it was confirmed whether the hologram pattern 7 was visually recognizable. The results are shown in Table 1.

[Comparative Example 1]
In this comparative example, a printed polyester film 1 was obtained in exactly the same manner as in Example 1, except that an aluminum vapor deposition layer was formed on the hologram pattern layer 3 and no printed layer 4a was formed. In this comparative example, the print layer 4b is formed in the same manner as in the first embodiment, and forms an image such as a predetermined display and design.

  Next, except that the printed polyester film 1 obtained in this comparative example was used, a three-piece can was formed in exactly the same manner as in Example 1 to obtain a printed polyester film-coated metal can of this reference example. .

  Next, the printed polyester film-coated metal can obtained in this comparative example was subjected to a retort treatment in exactly the same manner as in Example 1. And it was confirmed whether the hologram pattern 7 was visually recognizable. The results are shown in Table 1.

  From Table 1, the thickness of the aluminum thin film piece contained in the printed layer 4a is in the range of 0.01 to 0.5 μm on average, and the size in the plane direction is in the range of 5 to 25 μm on average. In the printed polyester film-coated metal can, it is clear that the hologram pattern 7 can be clearly seen even after the retort treatment.

  On the other hand, the hologram pattern 7 is unclear in the printed polyester film-covered metal cans of Reference Examples 1 and 2 in which the thickness of the aluminum thin film piece included in the printed layer 4a and the size in the plane direction are outside the above ranges. It is clear that it is visually recognized. Further, it is apparent that the hologram pattern 7 cannot be visually recognized after the retort treatment in the printed polyester film-covered metal can of Comparative Example 1 provided with an aluminum vapor deposition layer instead of the printed layer 4a.

  DESCRIPTION OF SYMBOLS 1 ... Printed polyester film for can body material coating, 2 ... Polyester film used as a base | substrate, 3 ... Hologram pattern layer, 4 ... Printed layer, 4a ... 1st printed layer, 4b ... 2nd printed layer, 5 ... Thermosetting A mold resin adhesive layer, 6 ... a cured overcoat layer, 7 ... a hologram pattern, 11, 23 ... a metal plate for a can body material, 12, 25 ... a protective coating layer.

Claims (5)

A printed polyester film that is heat-bonded via a thermosetting resin-based adhesive layer on the outer surface side of the can body of a metal plate for a can body material or a bottomed cylindrical can body,
The printed polyester film includes a hologram pattern layer having unevenness having a height difference of 0.1 to 2.0 μm on one surface of a polyester film serving as a substrate, and an aluminum thin film piece is partially formed on the hologram pattern layer. A first printing layer comprising a resin composition comprising an epoxy butyral resin and a polyisocyanate resin or a resin composition comprising a polyester polyurethane resin and a polyisocyanate resin, and a pigment in the other part. A second printing layer comprising a resin composition comprising an epoxy butyral resin and a polyisocyanate resin, or a resin composition comprising a polyester polyurethane resin and a polyisocyanate resin, comprising a display and an image of the pigment. the provided heat curing on the first printed layer and the second printing layer Printing polyester film, characterized in that it comprises a resin-based adhesive layer. In the printing polyester film of claim 1 Symbol placement, the aluminum thin film pieces included in the printed layer is in the range of the average 0.01~0.5μm thickness, the surface direction size average of 5~25μm Printed polyester film characterized by being in range. In the printing polyester film according to claim 1 or 2 Symbol placement, the aluminum thin film pieces contained in the printing layer, characterized in that comprises in the range of 40 to 80% by weight relative to the total amount of the resin composition of the printed layer Printed polyester film. With respect to the outer surface side of the can body portion of the metal can body, a hologram pattern layer provided with unevenness having a height difference of 0.1 to 2.0 μm is provided on one surface, and an aluminum thin film piece is partially formed on the hologram pattern layer. A first printing layer comprising a resin composition comprising an epoxy butyral resin and a polyisocyanate resin or a resin composition comprising a polyester polyurethane resin and a polyisocyanate resin, and a pigment in the other part. A second printing layer comprising a resin composition comprising an epoxy butyral resin and a polyisocyanate resin, or a resin composition comprising a polyester polyurethane resin and a polyisocyanate resin, comprising a display and an image of the pigment. the provided, printing poly comprising a thermosetting resin-based adhesive layer on the first printed layer and the second printing layer Ester film is printed polyester film coated metal can body, characterized in that it comprises a protective coating layer which is more formed on heating contact adhesive that via the heat-curable resin based adhesive layer. The printing polyester film coated metal can body according to claim 4, wherein the metal can body, the strip-shaped can body material for a metal plate welded can body or the can material metal both ends edges superimposed are welded joint A printed polyester film-coated metal can body, which is a bottomed cylindrical can body obtained by drawing or ironing a plate.

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