JP2002240197A - Film laminated drawn can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a can body not generating the elution of an exogenous endocrine disrupting chemical substance to content indended for a food can or discoloration such as sulfuration blackening or the like and having good corrosion resistance and beautiful printing appearance. SOLUTION: In a film laminated drawn can (including a deep-drawn can) obtained by one drawing processing or more than one drawing processings due to the press molding processing of a metal panel, an adhesive layer (A) and a thermoplastic polyester resin film layer (B) are provided on the surface of the metal panel becoming the inner surface side of a can. The adhesive layer contains an epoxy/polyester copolymer resin with a number average mol.wt. (Mn) of 6,000-30,000, which is obtained by copolymerizing an epoxy resin and a polyester resin in a weight ratio of 95:5-5:95, and a curing agent, and the drawn can is obtained by performing the molding processing of the metal panel coated with the layers (A) and (B), so that the drawing ratio of the final can body becomes 1.5-2.5 and the strain generated in the thermoplastic resin film layer by molding processing is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film-laminated drawn can (including a deep drawn can) obtained by drawing a metal plate one or more times.

[0002]

2. Description of the Related Art In the field of metal cans, conventionally, drawn cans obtained by pressing a steel plate or aluminum plate one or more times by pressing are mainly filled with fish meat, animal meat, grains, pet food and the like. It is widely used for so-called food cans. In such a drawn can made of a metal plate, the surface of the metal plate that hits the inner surface of the can was painted to ensure corrosion resistance. In addition, paint on the outer surface of the can
In many cases, a drawn can is obtained by directly performing a drawing process by a press from a printed coated plate, a so-called pre-coated material. However, when performing draw forming by pre-pressing directly from the pre-coated material, a high work ratio with a high drawing ratio is used due to damage to the coating film on the inner and outer surfaces of the can, distortion of the printed pattern on the outer surface, and deterioration of appearance. At present, in the case of cans with a high degree of processing, it is common to directly form and process a metal plate and then paint and print the inner surface or the outer surface.

[0003] A drawn can obtained from a painted plate whose inner and outer surfaces have been painted or printed in advance has been subjected to external surface printing as well as printing on a metal plate in consideration of the processing distortion of the final can body. However, local stretching and compression due to the molding process, and fine damage during the molding process are inevitable, and the printing appearance is, for example, a can that only forms the can body in a cylindrical shape like a three-piece can, or a drawing Ironing can (Dro
There is a drawback that it is inferior to a can that paints and prints on the inner and outer surfaces after molding as in wing & ironing can (DI can).

[0004] Regarding the inner surface of the can, as described above, since the squeezed can is filled with fish meat, animal meat, cereal, pet food, and the like, it sometimes contains high-concentration salt and the corrosiveness of the contents is low. Some are tough. In addition, since the contents of fish and animal meat as described above require a heat sterilization step by retort treatment, sulfur (S) is dissociated due to the decomposition of sulfur-containing proteins such as cystine contained in the meat and the coating film is formed. May react with the metal under the coating film.
In particular, in the case of a steel sheet, the reaction product is a compound called iron sulfide, which is black, and is called black sulfide or sulfur stain, which is not preferable because it impairs the appearance quality significantly.

[0005] Further, regarding the coating film on the inner surface of the can, since the drawn can is obtained by molding a pre-coated prepainted material as described above, a paint which has good workability and does not cause blackening of sulfurized black is used. Recently, it has recently been found that many of these paints have a concern about the problem of exogenous endocrine disrupting chemicals (environmental hormones) that has become a hot topic.

On the other hand, in recent years, the application of a film laminating material to a metal can from conventional coating has become conspicuous, and many proposals have been made. For example, Japanese Patent Application Laid-Open No. 2-2
JP-A-63-523, JP-A-3-133523, JP-A-4-237524 and the like are directed to two-piece cans, and are disclosed in JP-A-5-112361, JP-A-5-111979, and JP-A-5-1111979. JP-A-31868 discloses a three-piece can. Also, JP-A-61-149341, JP-A-3-87
No. 249, JP-A-4-344231, etc.
Laminated materials in which an organic resin polymer is interposed between a resin film and a metal plate have been proposed.

[0007] In the case of such a film-laminated can, it is considered that the above-mentioned problem of endogenous endocrine disrupting chemical substances (environmental hormones) is hardly worried by properly selecting a resin component. Most of the prior art is basically directed to beverage cans, not food cans. In addition, even with a laminated material in which an organic resin polymer is interposed between a resin film and a metal plate, which is the above-mentioned prior art, the sulfide blackening problem, which is particularly problematic for steel materials, cannot be easily solved. Furthermore, secondly, not all of the disclosed contents work effectively on the corrosion resistance as a food can, and there are many cases where there is a problem with respect to adhesion and corrosion resistance.

Therefore, even if the prior art as described above is applied as it is, the problem of adhesion and corrosion resistance as a food can, especially the blackening of sulfurized black, cannot be easily solved due to the film properties, the adhesive or the adhesion primer. At present, it is not easy to solve this problem due to film thickness and other cost problems. Under these circumstances, even in the field of food cans, there is no dissolution of exogenous endocrine disrupting chemicals into the contents at low cost and no discoloration such as blackening of sulfide on steel materials. There has been a strong demand for the appearance of a can having good corrosion resistance, which is a necessary characteristic, and a beautiful printed appearance.

[0009]

DISCLOSURE OF THE INVENTION The present invention does not dissolve exogenous endocrine disrupting chemicals into the contents of food cans as described above, and has good corrosion resistance to steel and aluminum materials. Further, it is an object of the present invention to provide a good can body having a beautiful printed appearance and no discoloration such as blackening of sulfide which is a problem particularly in steel materials.

[0010]

SUMMARY OF THE INVENTION A first aspect of the present invention is to provide a drawn can (including a deep drawn can) obtained by a single drawing process or a plurality of drawing processes by press forming a metal plate. The metal surface on the inner surface side has (A) an adhesive layer and (B) a thermoplastic polyester resin film layer. The adhesive layer of (A) has (A) a number average molecular weight (Mn) of 340 to 10,000. Epoxy resin,
(B) A polyester resin having a number average molecular weight (Mn) of 1,000 to 20,000 is copolymerized in a weight ratio of epoxy resin to polyester resin in a range of 95: 5 to 5:95, and a number average molecular weight (Mn) of 6,000 to 6,000. 100,000 parts by weight of 30,000 epoxy-polyester copolymer resin,
Contains 5 to 20 parts by weight and has a dry thickness of 5 to 50 mg / dm.
² , and the thermoplastic polyester film (B) has a thickness of 8 to 30 μm, a melting point (Tm) of 210 ° C. or more, and the maximum of 2θ detected at 22 ° to 28 ° by X-ray diffraction. 700 cps high peak intensity
7000 cps in the range from 1.5 to 2.5 as a drawing ratio of the final can body from the metal plate coated with (A) and (B). And a film-laminated squeezed can characterized in that the strain in the thermoplastic polyester resin film layer is released by molding. A second aspect of the present invention is that a thermoplastic polyester resin film layer / ink layer / clear coat layer is directly coated on a metal plate by thermocompression bonding on the outer surface side of the drawn can from the metal side, or the (A) A film-laminated draw can, either coated with an adhesive layer. The third aspect of the present invention is that the thermoplastic polyester resin film layer coated on the inner surface side and the outer surface side of the can has a coloring agent of 5 to 2 times.
The film-laminated drawn can according to claim 1 or 2, which contains 0% by weight. The coloring agent refers to an inorganic and / or organic dye / pigment. The fourth aspect of the present invention is the film laminated drawn can according to any one of claims 1 to 3, wherein the adhesive layer contains a white pigment.

[0011] The film-laminated squeezing can having such a structure is characterized in that the film coated on the inner and outer surfaces on both the aluminum material and the steel material has a high adhesion and a high salt content. Even when filled, it shows high corrosion resistance, there is no problem of blackening of sulfide which is a problem particularly in the case of steel materials, and since the printing ink is applied to the upper layer of the film on the outer surface, a beautiful printed appearance can be obtained. Also,
There is no problem of endogenous endocrine disrupting chemicals (environmental hormones) mentioned above, and a can that can be safely and safely eaten can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the drawn can of the present invention will be described in detail. First, a metal plate applied to the present invention will be described. In the present invention, as the metal plate, a surface-treated steel plate having a thickness of 0.15 mm to 0.22 mm and an aluminum plate having a thickness of 0.20 mm to 0.25 mm are applied. The thickness of steel plate and aluminum plate is
It is a thickness that does not cause deformation of the can in the retort sterilization process performed after filling the contents. As the steel plate and the aluminum plate, those subjected to a surface treatment are applied. In the case of a steel sheet, an electrolytic chromic acid-treated steel sheet, a Ni-plated steel sheet, a Sn-plated steel sheet, or the like obtained by subjecting a cold-rolled steel sheet usually used as a container material to a surface treatment is applied.

The electrolytic chromic acid-treated steel sheet is commonly called TFS (tin-free steel) and is generally used as a steel sheet for containers and is not special. 30-120 mg / m ² ,
It is preferable that a hydrated chromium oxide layer on the upper layer has an adhesion amount on one side of 10 to 30 mg / m ^{2 in} terms of chromium, and both adhesion and black sulfide modification are good. If the metal chromium layer has an adhesion amount on one side of less than 30 mg / m ² , black sulfide denaturation becomes poor, which is not preferable. On the other hand, 12
If it exceeds 0 mg / m ² , the effect according to the adhesion amount is not observed in both adhesion and blackening with sulfide, and the effect is not economical because it saturates. The hydrated chromium oxide layer has an adhesion amount on one side in terms of chromium of 10 to 30 mg / m ² , which is good in both adhesion and black sulfide modification. If it is less than 10 mg / m ² , delamination such as film peeling may occur in the retort treatment, which is not preferable in terms of adhesion.

In the case of a Ni-plated steel sheet, the amount of Ni deposited on one side is 200 to 1000 mg / m ² , and the above-mentioned electrolytic chromic acid treatment is applied to the upper layer, and the hydrated chromium oxide layer is converted to chromium in an amount of 10%. ３０30 mg / m ² , a single-sided Ni adhesion amount of 200-1000 mg / m ² , and a single-sided Cr adhesion amount of 5-100 mg / m ² on the upper layer
Ni the chemical conversion coating mainly comprising ² organic resin has been subjected
A plated steel sheet is applied.

In the case of a Sn-plated steel sheet, the amount of Sn deposited on one side is 500 to 3000 mg / m ² , and the upper layer is treated with electrolytic chromic acid and the hydrated chromium oxide layer is 10 to 30 mg / m 2 in terms of chromium. ² conducted Sn-plated steel sheet,
Sn adhesion amount of one side can be cited Sn plated steel sheet chemical conversion film is applied mainly an organic resin 5 to 100 mg / ^{m 2} as Cr deposition amount thereon at 500~3000mg / ^{m 2,} Ni In the case of a plated steel sheet, Ni plating is performed with a Ni adhesion amount on one side of 15 to 50 mg / m ² , and the Sn adhesion amount on one side is 500 to 1500 m on the upper layer.
g / m ² of Sn-plated steel, and a chromium oxide hydrate layer of 10 to 30 mg / m ^{2 in} terms of chromium conversion on one side by electrolytic chromic acid treatment on the upper layer, Ni adhesion on one side Ni in an amount of 15 to 50 mg / m ²
Plating is performed, and the Sn adhesion amount on one side is 500 to
Plated with Sn of 1500 mg / ^{m 2,} the chemical conversion coating mainly comprising organic resin 5 to 100 mg / ^{m 2} can be cited Sn-Ni-plated steel sheet or the like which has been subjected to a Cr coating weight of one surface thereon.

Ni and Sn form compounds such as nickel sulfide and tin sulfide, both of which are black and are the above-mentioned black sulfide-discoloring metals. Such corrosion can be avoided if the film configuration is a porester resin film.

Aluminum plates are usually used as cans.
3004 aluminum alloy, 5052 aluminum alloy
Gold, 5182 series aluminum alloy, 5T50 series aluminum alloy, etc.
The chromium content is 5 to 80 mg / m²Phosphorus attached
Acid chromic acid treatment, zirconium content of 9 to 17 mg /
m²Chemical conversion treatment such as zirconium phosphate treatment
What has been applied applies. Furthermore, also of aluminum
In this case, there is no phenomenon such as blackening of sulfuration,
Phosphoric acid or phosphoric acid as a chemical conversion treatment that emphasizes adhesion
Zirconium and organic such as phenolic resin and acrylic resin
Organic-inorganic composite chemical conversion treatment obtained from resin-based treatment liquid
Coatings are particularly effective. Organic-inorganic composite chemical conversion coating
Organic and organic materials containing only phosphorus (P) and organic resin
In the case of combined chemical conversion treatment, the amount of coating
2 to 7 mg / m as phosphorus (P) adhesion amount ², Organic resin
5 to 50 mg / m as carbon (C) adhesion amount²Is best
It is. In addition, organic films containing zirconium in the coating
In the case of a chemical conversion coating, the adhesion amount is
(P) 2 to 7 mg / m as adhesion amount², Film carbon (C)
5 to 50 mg / m as adhesion amount², Zirconium adhesion
5 to 20 mg / m²Is optimal.

Next, the adhesive applied in the present invention will be described. Before that, an example of the method for obtaining the drawn can of the present invention, in which the adhesive is applied to one surface of a thermoplastic polyester resin film, is used. The steps will be described below. (1) A step of applying and drying an adhesive on one side of a thermoplastic polyester resin film (2) A thermoplastic sheet with the adhesive obtained in (1) is provided on both sides of the metal plate, at least on the inner side of the can. Step of thermally laminating and coating the polyester resin film so that the adhesive is in contact with the metal surface. (3) Step of printing and painting the outer surface side of the can. (4) Drawing process. (5) Obtained above. Process of post-heating the drawn can

The adhesive applied in the draw can of the present invention is:
(A) an epoxy resin having a number average molecular weight (Mn) of 340 to 10,000, and (b) a number average molecular weight (Mn) of 1000
A polyester resin having a number average molecular weight (Mn) of 6000 to 300 obtained by copolymerizing a polyester resin having a weight ratio of epoxy resin to polyester resin of 95: 5 to 5:95.
An adhesive comprising 100 parts by weight of an epoxy-polyester copolymer resin of No. 00 and a curing agent such as an amino resin and / or a phenol resin in an amount of 0.5 to 20 parts by weight, or an additive such as a pigment added thereto. . Furthermore, in the present invention, 0.01 to 5 parts by weight of a curing catalyst can be contained.

The properties that should be retained as an adhesive include: first, good wettability to the metal surface and film surface; second, strong adhesion to the metal surface and film surface; Ensuring a cohesive force that does not break the adhesive is cited as an important factor.

The present inventors have conducted intensive studies on the bonding system in the above-mentioned step as an example of the method for producing the drawn can of the present invention. As a result, the thermoplastic polyester resin film was converted into an adhesive having the above specific composition. The present inventors have found that by coating through the intermediary layer, it is possible to secure adhesion and corrosion resistance that have not existed before, and have reached the present invention. From the viewpoint of the properties to be maintained as the adhesive described above, the epoxy-polyester copolymer resin, which is the main component of the adhesive of the present invention, is characterized in that the epoxy resin is involved in the reaction with the curing agent and the heat resistance, and the aggregation of the adhesive itself. It is considered that the polyester resin plays a role of increasing the force, while the polyester resin plays a role of ensuring the wettability and the adhesion with the metal plate or the polyester resin film. Therefore, in order to ensure wettability, a polyester resin component is particularly effective for a thermoplastic polyester resin film, and the number average molecular weight (Mn) is particularly preferably 1,000 to 200.
Polyester resin components in the range of 00 are suitable,
Further, those having a number average molecular weight (Mn) of 1,000 to 10,000 are particularly preferred.

On the other hand, an epoxy resin component is effective for maintaining cohesive force as an adhesive and preventing destruction by molding, and for maintaining heat resistance. In the present invention, the number average molecular weight (Mn) is defined as an epoxy resin component. An epoxy resin in the range of 340-10000 is applied. In particular, the number average molecular weight (M
As n), 340 to 5000 is a preferable range.
In order to maintain such properties as a main component of the adhesive, it is preferable that the epoxy resin and the polyester resin are copolymerized in a weight ratio of 95: 5 to 5:95. . The molecular weight of the epoxy-polyester copolymer resin, which is the main component of the adhesive, is in the range of 6,000 to 30,000 as the number average molecular weight (Mn). The adhesive function of the adhesive of the present invention is completed by heating after the drawing can, which is the final step of the manufacturing process for obtaining the drawn can described above.

After a can body and a can lid are formed from a coated metal sheet coated with a surface-treated steel sheet or an aluminum alloy sheet with a thermoplastic resin, the stress strain generated in the thermoplastic resin layer by these forming processes is released. For this purpose, post-heating treatment may be applied to the molded article as disclosed in JP-A-48-49590, JP-A-48-61584, and JP-A-52-65.
Although this is well known in Japanese Patent Application Laid-Open No. 579, Japanese Patent Application Laid-Open No. 53-141886, etc., this is also effective in the present invention. By post-heating treatment to this molded product,
The adhesion of the thermoplastic resin layer to the metal plate is improved, and the corrosion resistance of the molded product is also improved.

When the adhesive is completely cured in the steps (1) and (2) in the manufacturing process of the drawn can, the processing distortion generated in the drawing process of (4) is large, and after filling the contents, Film peeling may occur in the retort sterilization performed. Only by heating the drawn can after the forming process of (4) to complete the curing, the obtained can body can have excellent retort resistance and corrosion resistance. The reason is that it is more flexible to keep the curing of the adhesive in an appropriate curing state during molding processing, and it is better to follow the molding processing and then cure the adhesive again to obtain better adhesion It is because it was found that it can be done.

Accordingly, in order to prevent the adhesive itself from being destroyed even when the molding process is performed, it is preferable that the degree of curing of the adhesive before the molding process by heating is suppressed to some extent as in the present invention. In order to follow the molding process, the cohesive force of the adhesive is advantageously higher in the molecular weight, so the molecular weight of the adhesive main agent is important. The number average molecular weight (Mn) of the copolymer of the epoxy resin and the polyester resin as the main components is 600.
A range of 0 to 30000 is suitable. If the number average molecular weight (Mn) of the main agent is less than 6000, the cohesive force becomes insufficient, and the adhesive itself may be destroyed by molding and the film may be peeled off. On the other hand, the number average molecular weight (Mn)
If it exceeds 30,000, the cohesive strength is sufficient, but the viscosity is increased and good coating properties cannot be obtained, which is not preferred.
Since the cohesive force is directly related to the degree of curing of the adhesive itself, it varies depending on the amount of the curing agent added, the laminating temperature, and the baking conditions for external printing / painting. Number average molecular weight (Mn) is 8000
~ 20,000 is preferred.

The epoxy equivalent of the main ingredient is 100
The range is from 0 to 30,000. The epoxy equivalent is a factor directly related to the curing reaction and also has a relationship with a curing agent described later, but within this range, an appropriate cured state based on the above-mentioned heat history can be obtained.

Curing agents that promote the curing of the main component include amino resins such as urea resins, melanin resins and benzoguanamine resins, phenol monomers such as phenolic acid and cresylic acid, and resol resins and novolaks obtained by condensation with formalin. A phenol resin such as a resin alone or a mixture of both is applied. It is needless to say that a so-called etherified resin in which a functional group that reacts with the main agent is covered with an alkyl group or the like can be used as the curing agent such as an amino resin and a phenol resin. An optimum etherifying agent to be volatilized may be appropriately selected depending on printing baking conditions and post-heating conditions of the can body after forming. The amount of addition is 0.5 to 20 parts by weight based on 100 parts by weight of the epoxy-polyester copolymer resin as the main component. The amount of the curing agent added is 0.
If the amount is less than 5 parts by weight, the curing may be insufficient and the cohesive force may not be secured, and the peeling of the film due to the destruction of the adhesive itself may occur particularly when the drawing ratio is large, which is not preferable.
On the other hand, if the amount exceeds 20 parts by weight, the curing of the adhesive is excessively advanced, which may cause breakage during molding, which is not preferable. The amount of the curing agent is preferably epoxy-
The optimal amount of the curing agent is 1 to 15 parts by weight based on 100 parts by weight of the polyester copolymer resin, but strictly speaking, the laminating conditions and the baking conditions for painting and printing on the outer surface side of the can,
Since the optimum amount varies depending on the degree of drawing (drawing ratio) of the drawing forming, it is necessary to appropriately select the amount. Furthermore, the role of the adhesive in the above-mentioned blackening resistance to sulfurization also plays a large role. Particularly, when a phenol resin is used as a curing agent, it effectively acts to prevent blackening of sulfurization. Curing agents mainly composed of resin are preferred.

It is also possible to add a phosphoric acid-based or sulfonic acid-based curing catalyst for accelerating the curing. The amount of the curing catalyst to be added is 0.01 to 5 parts by weight. It is desirable to appropriately select an optimum amount from the relationship of lamination conditions, baking conditions for coating and printing on the outer surface, and post-heating conditions of the can body after forming.

In the present invention, it is necessary to strictly control the laminating conditions, the printing and coating conditions of the outer surface, and the post-heating conditions of the can body after the molding, for the reasons described above. By applying, a drawn can having excellent quality that can secure good adhesion and also good corrosion resistance can be obtained.

Further, in order to obtain good adhesiveness, it is necessary to ensure sufficient wettability to a metal plate or a thermoplastic polyester resin film as described above. Therefore, it is necessary to select optimum laminating conditions in which the laminating temperature, pressure, speed and the like are adapted to the melting temperature of the adhesive. As a specific example of the adhesive of the present invention, for example, when a base resin having a high mixing ratio of an epoxy resin is applied, it is necessary to keep the laminating temperature high.

The amount of the adhesive to be applied is 5 to 50 mg / dm ² as a dry thickness, including the main agent, the curing agent and the curing catalyst. If the dry thickness is less than 5 mg / dm ² , it is difficult to uniformly coat the surface of the metal plate, and a portion that is not wet locally occurs, which is likely to cause film peeling (delamining), which is not preferable. On the other hand, the upper limit of 50m
When the value exceeds g / dm ² , the adhesive is of a hardening type, so that residual strain due to hardening occurs, and when the amount of adhesion is large, cohesive failure of the adhesive occurs in molding processing, resulting in impairment of adhesion. In some cases, it is not preferable that the dry thickness exceeds 50 mg / dm ² in this sense, and it is not economical.

The adhesive may be applied to a thermoplastic polyester resin film or applied to a metal plate, and it is important to select an appropriate adhesive in consideration of equipment. When adopting a method of applying and drying an adhesive on a thermoplastic polyester resin film, it is desirable that the adhesive be dried at a temperature at which hardening reaction hardly occurs in application and drying,
Drying conditions at 100 to 140 ° C. for 4 to 10 seconds are preferred.
In the case where such a thermoplastic polyester resin film with an adhesive is continuously wound on the same line in the same line without being wound, there is no particular problem. However, when the adhesive is applied to the polyester resin film, dried and wound up once, and then rewound onto the metal plate and coated again, there is no blocking so that the unwinding of the thermoplastic polyester resin film with the adhesive goes smoothly. , So-called tack-free. For that purpose, the glass transition temperature (Tg) of the base material is preferably higher, and is preferably at least 20 ° C. or higher. It is also effective to add an anti-blocking agent such as polyethylene fine particles, silicon oxide, and organic silicate to the adhesive. However, the addition of the anti-blocking agent leads to a decrease in adhesion, so that the amount of addition should be carefully considered. It is necessary to add 1
0% or less is preferable.

Next, the thermoplastic polyester resin film coated on the inner surface side of the can will be described. In the case of a squeezed can as in the present invention, the contents to be filled are mainly fish meat, meat, cereals and pet food as described above, and after filling the contents, retort treatment is performed for both cooking and sterilization, In the most severe case, the retort treatment is performed by steam at 113 ° C. for 100 minutes or at 125 ° C. for 60 minutes.
It is necessary that the thermoplastic polyester resin film has a heat resistance of at least ℃ or more. The thermoplastic polyester resin film to be coated is a polyester resin comprising an acid component such as terephthalic acid, isophthalic acid, adipic acid and sebacic acid and an alcohol component such as ethylene glycol and butylene glycol, for example, polyethylene terephthalate (PET), polybutylene Terephthalate (PBT), polyethylene soyphthalate (P
A homopolymer such as EI) or a copolymer, for example, a copolymer resin of polyethylene terephthalate and polyethylene isophthalate, further a blend resin of such homopolymers, a blend resin of homopolymer and copolymer, a blend resin of copolymers, A film obtained from the above is applied. Melting point of resin film (T
m) and the heat of cold crystallization (Hc) can be obtained by appropriately selecting the acid component and the alcohol component, the degree of the copolymer, the resin composition to be blended and the mixing ratio thereof, and the like.

Among the thermoplastic polyester resin films, a biaxially oriented thermoplastic polyester resin film which is resistant to the above-mentioned retort treatment and which is particularly oriented and crystallized is optimal from the viewpoint of protecting the contents. However, a thermoplastic polyester resin film having a high degree of orientation generally has a large residual strain at the time of stretching of film formation, and when subjected to a forming process such as a draw can, the residual strain exceeds the adhesive strength, and the film peels ( Delamination) often occurs. Therefore, from the viewpoint of both securing the adhesion and protecting the can body and the contents, it is necessary to control the degree of orientation of the thermoplastic polyester resin film to an optimal range. The degree of orientation of the thermoplastic polyester resin film to be coated is the highest among peaks in which 2θ is detected at 22 ° to 28 ° at least by measurement of a film of the laminate before being subjected to the drawing process by X-ray diffraction. 700 cps-7000 c peak intensity
It must be a thermoplastic polyester resin film in the range of ps.

When the intensity of the highest peak among the peaks detected by X-ray diffraction, which is the lower limit, is less than 700 cps, the adhesion is good, but the corrosion resistance occurs, especially when a steel material is used. The blackening problem of sulfurization described above is not preferred because it may occur particularly at a portion near the can mouth where the plating layer or the chemical conversion coating layer is broken by drawing. Furthermore, a thermoplastic polyester resin film having a small peak detected by measurement by X-ray diffraction, that is, a peak intensity of less than 700 cps, generally has poor thermal stability in many cases, for example, when an adhesive is applied to a film and dried. The film may shrink due to the heat of the film, or the film may shrink due to the heat of the laminate for laminating the film to the metal plate, or if it is severe, the film may wrinkle, which may cause a deterioration in the laminating property. is there. In this sense, a thermoplastic polyester resin film having a peak detected by X-ray diffraction of less than 700 cps is not preferable. On the other hand, when the intensity of the highest peak among the peaks detected in the measurement by X-ray diffraction, which is the upper limit, exceeds 7000 cps, corrosion resistance, particularly blackening of sulfide, does not occur even with a steel material, and there is no problem. In such a case, the adhesion is poor, and the film may be peeled off during the retort treatment, which is not preferable.

As described above, the lower limit of the intensity of the highest peak among the peaks detected by the X-ray diffraction is determined from the corrosion resistance such as blackening of sulfide in the case of using steel as a raw material, and from the measurement by the X-ray diffraction. The upper limit value of the intensity of the highest peak among the peaks detected in the above is determined from the adhesion when aluminum is used as the material, and is preferably 850.
The range of cps to 6000 cps is optimal. Note that X
In the measurement by line diffraction, the peak detected at 2θ of 22 ° to 28 ° is, for example, when ethylene terephthalate is the main repeating unit, the highest peak appears at about 2θ of around 26 °, and butylene terephthalate is the main peak. In the case of the repeating unit, the highest peak appears at about 2θ of around 24 °. X
X-ray diffraction is measured, for example, using an X-ray diffractometer r manufactured by Rigaku Corporation.
40 kV with Cu target (Cu-Kα) in ad-B,
When measured under the condition of 20 mA, 2θ is 22 ° to 28 °.
強度 is the highest peak intensity among the peaks detected in ゜.

The highest peak intensity among peaks detected at 2θ of 22 ° to 28 ° is 700 cps to 7000 c
As a means for obtaining a ps range, to appropriately select the stretching ratio at the time of film formation when manufacturing a thermoplastic polyester resin film and the heat fixing conditions to be performed after stretching, and further appropriately the lamination conditions for coating the film Achieved by choice.

Further, the thermoplastic polyester resin film of the present invention preferably has an intrinsic viscosity (IV) of 0.50 or more. Intrinsic viscosity (IV) is an index indicating the average molecular weight of the resin. When the intrinsic viscosity is less than 0.50, the impact strength of the resin film is low, and the resin film is formed at the time of retort treatment of the can, which is formed at the time of drawing can molding. If the film on the projection ring (expansion ring) cracks on the bottom of the can to minimize the expansion of the can, or if the can body filled with the contents is dropped, an impact is applied to that part Not only is the material deformed, but at the same time, the resin film is cracked by the impact and deformation, and when severe, this becomes the starting point of corrosion of the metal body. The property of the can body against falling after filling the contents is called dent resistance.However, in the case of highly corrosive contents, it may become a perforated can, and poor dent resistance has a serious problem. It is not preferable.
The phenomenon of cracks in the film as described above is basically a problem of the impact strength of the film. The impact strength is better as the intrinsic viscosity is higher. In many cases, a quality that does not cause a problem in practical use is ensured due to the mutual effect with the layer. However, for contents having strong corrosiveness, a higher value is safer, and preferably 0.55 or more. In the present invention, the intrinsic viscosity (IV) of the thermoplastic polyester resin film is determined by measuring the thermoplastic polyester resin film in a solution of phenol and tetrachloroethane at a weight ratio of 6: 4 by 0.100 ± 0.0 by an Ubbelohde viscometer.
It is a value measured at 30.0 ± 0.1 ° C. after dissolving 03 g.

The melting point (Tm) of the thermoplastic polyester resin film of the present invention is 210 ° C. or higher. In the present invention,
The outer surface is printed and painted before drawing, but the drying temperature of ink and clear paint is usually 200 ℃ even at the highest temperature.
It is important that the polyester resin film on the inner surface is not softened at least at this temperature. In this sense, the melting point (T
m) is 210 ° C. or higher. When the melting point (Tm) of the thermoplastic polyester resin film is lower than 210 ° C., it is not preferable because it softens during drying of the outer surface printing / painting and causes defects in the inner surface film. In the present invention, the melting point (Tm) of the resin film is a temperature at which the maximum value of the crystal melting endothermic peak is measured by a differential scanning calorimeter (DSC) at a heating rate of 10 ° C./min.

The thermoplastic polyester resin film of the present invention has a thickness of 8 to 30 μm. The thickness of the film is basically limited in view of the corrosion resistance of the can and the peeling of the film (delamining) occurring during the retort sterilization treatment performed after filling the contents. As described above, the squeezed can of the present invention is filled with fish meat, meat, cereals, pet foods, and the like. Among these contents, there are many so-called salted foods seasoned with soy sauce or salt. , The contents are highly corrosive to aluminum and iron. Further, when the inner film is made of a steel plate, it is necessary to play a role of preventing the occurrence of blackening resistance described above. The blackening resistance to sulfurization generated in a steel sheet material occurs not only in a defective portion of the film but also in a sound portion of the film if the surface treatment of the steel sheet material is not sound. Therefore, the role of the film in blackening resistance to sulfurization is great. In general, blackening of sulfuration mainly occurs during the above-described retort sterilization, and then gradually spreads in the environment where it is placed, particularly when the temperature is high. Sulfur blackening occurs when sulfur-containing proteins are decomposed during retort treatment, and the resulting sulfur is [HS
⁻ ) And [S ⁻² ] ions, which permeate the film together with water and react with the material steel sheet to form iron sulfide. Therefore, the barrier property of the film is important. For example, retort sterilization is performed at 135 ° C for 30 minutes or 12 in severe cases.
It is performed under conditions such as 5 ° C. for 50 minutes, and the thermoplastic resin has slightly different resistance depending on the glass transition temperature of the resin, but is a severe condition for any resin film.
The barrier properties of the film differ depending on the composition and density of the resin, but in the case of the same resin composition and the same crystalline state,
The greater the film thickness, the better the barrier properties. Therefore, the corrosion resistance is better as the film thickness is thicker, but if the film thickness is thicker, the residual strain at the time of forming a stretched film and the distortion at the time of forming the can body are increased, which may cause delamination at the retort treatment. . Therefore, in the present invention, the film thickness is 8
Although the thickness is limited to 30 μm, the film thickness is optimally 10 to 25 μm in consideration of the practical practical characteristics and economy of the can body.

Next, the coating structure on the outer surface of the can will be described. On the metal surface which is the outer surface side of the drawn can of the present invention,
From the metal side, the thermoplastic polyester resin film layer / ink layer / clear coat layer is directly coated on the metal plate by thermocompression bonding, or is coated via the above-mentioned adhesive layer. The ink layer is used to display the contents such as characters and trademarks, and is printed in a distorted shape in advance in consideration of deformation due to molding.However, the ink itself is not special, The used ink can be applied as it is. The clear coat layer suppresses damage during the forming process of the ink layer and discoloration and deterioration during retort treatment.However, if it is not special, it has good slipperiness and good retort resistance. A clear coat for cutting plates can be applied. The thermoplastic polyester resin film on the outer surface of the can is effective in ensuring sharpness and sharpness of the printed appearance.

In most of the current paint and printing cans, a metal plate is coated with a size coat or white coat, and printing is performed on the upper layer. However, in the case of a size coat or white coat paint, roll spots are inevitable. Further, since the coating thickness is several μm, it is easily affected by the increase in the roughness of the metal plate caused by the drawing process, and as a result, the sharpness and sharpness of the printed appearance are reduced. On the other hand, when printing is performed on the upper layer of a film having a sufficient thickness as in the present invention, the printing is hardly affected by the increase in the roughness of the metal plate caused by the drawing process as described above, and the sharpness of the printed appearance, It is possible to ensure sharpness. In this sense, the thickness of the thermoplastic polyester resin film coated on the outer surface side of the can is optimally 10 to 15 μm.

In the present invention, the thermoplastic polyester resin film coated on the inner and outer surfaces of the can contains one or more kinds of inorganic coloring pigments, organic coloring pigments and organic coloring dyes, and may be colored. Is done. For example, regarding the outer surface side of the can, especially in the case of steel material, unlike aluminum material, the brightness is low and black because the spectral reflectance inherent to metal is low, and when the same printing is performed, the printed appearance looks dark and glossy Hardness is remarkably inferior. However, when printing is performed on a film containing a white titanium oxide pigment in a polyester resin film, for example, the appearance of printing is greatly improved even with a steel material drawn can.

Also, on the inner surface of the can, a colored film is effective from the viewpoint of a color effect for making the content look appetizing, and in this sense, in the present invention, the heat applied to the inner and outer surfaces of the can is reduced. A plastic polyester resin film containing one or more of an inorganic coloring pigment, an organic coloring pigment, an organic coloring dye and the like is also applicable. The amount to be contained in the thermoplastic polyester resin film is from 5 to 20% by weight, but if it is less than 5% by weight, the coloring effect is not particularly observed when steel is used as a material, which is not preferable. On the other hand, if it exceeds 20% by weight, the coloring effect is not so great and becomes saturated, so that it is not economical and the adhesion may be poor.

The inorganic and organic coloring pigments or coloring dyes contained in the thermoplastic polyester resin film are not particularly limited. However, when they are contained in the polyester resin film on the inner and outer surfaces of the can, the retort is naturally used. It goes without saying that it is necessary to select a substance that does not dissolve in the treatment, especially a substance that does not have any problem on the inner surface in terms of food hygiene and does not dissolve in the contents during storage.

As the thermoplastic polyester resin film on the outer surface side of the can, the above-mentioned thermoplastic polyester resin film having the resin composition and melting point (Tm) coated on the inner surface side of the can can be used. Therefore, it is necessary to select a thermoplastic polyester resin film having an optimum melting point (Tm). That is, in the case of coating via an adhesive layer, the adhesive and the thermoplastic polyester resin film used on the inner surface side of the can described above can be applied as they are, and there is no problem. However, when the thermoplastic polyester resin film is directly thermocompression-bonded to a metal plate and coated, there are a method of sequentially coating the metal plate surface and a method of simultaneously coating both surfaces. In the case of the sequential coating method, the lamination temperature is high. What is necessary is just to coat a metal plate from the side. When only simultaneous coating is possible due to the equipment, the heat with the adhesive on the inner surface is determined from the melting point (Tm) of the thermoplastic polyester resin film and the onset temperature (Tm-s) of the crystal melting endothermic peak measured by DSC. It is desirable to select a thermoplastic polyester resin film that does not greatly differ from the lamination temperature of the thermoplastic polyester resin film.

The drawn can applied in the present invention is a can having a drawn ratio in the range of 1.5 to 2.5. The drawing ratio is represented by the ratio of the blank diameter (Lb) to the drawn can diameter (Ld), and indicates that the value of Lb / Ld is in the range of 1.5 to 2.5. If the drawing ratio is less than 1.5, the volume of the can is too small to fill the contents and is not substantial and has no commercial value. On the other hand, when the drawing ratio exceeds 2.5, distortion due to molding processing becomes too large, and the printing on the outer surface of the can is distorted, and the one having a beautiful printed appearance at the corner is impaired, which is not preferable. In addition, even in the point of adhesion, there is a high risk that the decrease in adhesion will lead to peeling of the film, which is not preferable.

In the present invention, in order to further strengthen the adhesiveness of the film layer coated on the inner and outer surfaces after drawing, the can after molding is subjected to a temperature of 170 ° C. to 220 ° C. for 3 hours.
Post-heating is preferably performed in the range of 0 to 120 seconds. In particular, when the drawing ratio is high, the polyester resin film on the inner surface and the outer surface side may cause local peeling (delamining) in the retort sterilization step after filling the contents, which is not preferable.
In order to prevent this, it is effective to complete the curing of the adhesive described above, and at the same time, to reduce the distortion caused by the molding process by heating.
Post-heating may be performed at a temperature of 70 ° C. to 220 ° C. for a period of 20 seconds to 120 seconds. When the heating temperature is lower than 170 ° C., if the heating is performed for a long time, the curing of the adhesive proceeds, and the distortion of the thermoplastic polyester resin film formed in the molding process is removed, and the adhesion is ensured, but the productivity is reduced. It becomes a problem and is not economical. On the other hand, when the temperature exceeds 220 ° C., depending on the heating time, the above-described curing of the adhesive proceeds excessively, and conversely, the cohesive force is reduced, so that the adhesion and the dent resistance are deteriorated,
Even from the surface of the thermoplastic polyester resin film, the orientation sharply decreases depending on the resin composition, the corrosion resistance and the dent resistance described above may be inferior, and furthermore, the outer layer may discolor and impair the appearance. There is not preferred.

The post-heating time of the can body after molding is 2
The time is 0 seconds to 120 seconds, but it goes without saying that this time can be shortened when the heating temperature is high, and can be lengthened when the heating temperature is low. As the post-heating condition of the can body after the forming process, the heating temperature is 180
The heating time at 20 ° C. to 210 ° C. is preferably in the range of 20 seconds to 100 seconds. In this range, the curing of the adhesive does not proceed excessively and does not affect the discoloration of the outermost clear coat layer on the outer surface. In addition, it can remove the distortion of the thermoplastic polyester resin film entered by the molding process,
The retort treatment does not cause delamination, and the printed appearance of the outer surface of the can can be kept beautiful.

A normal heating furnace such as an electric furnace or a hot blast furnace can be used as a method for heating the can body. The atmosphere temperature of the heating furnace is set to 170 ° C. to 220 ° C. and the inside of the furnace is maintained for 20 seconds to It is preferable that the light is passed within a range of 120 seconds.

When the can body is post-heated, from the viewpoint of protection of the thermoplastic polyester resin film on the inner surface, when the can body is passed through a heating furnace by being put on a belt made of a net or the like, for example, It is important to put the outer surface of the film and pass it through and heat it so that it does not contact the inner film.

[0052]

EXAMPLES Hereinafter, the effects of the present invention will be described specifically with reference to examples, but the present invention is not limited thereto. The evaluation method used in this example is as follows. (1) The adhesion of the drawn can was determined by performing a steam retort treatment at 125 ° C. for 30 minutes in the presence of a flange opening where the lid was not tightened, and visually inspecting the peeling state of the film.
The evaluation was performed by setting evaluation criteria as follows. ：: good without peeling □: slight peeling occurred at the opening cut edge △: peeling about 1/2 of the flange occurred ×: peeling occurred from the flange to the can body (2) soundness of the resin film on the inner surface of the can About sex, 1.
Electrolyte solution containing 0.1% surfactant added to 0% saline solution is filled in the can body, and the can body is used as an anode, the copper wire inserted into the electrolytic solution in the can body is used as a cathode, and an applied voltage of 6 V is applied for 3 seconds. Was measured to evaluate the soundness of the resin film coating (hereinafter, this evaluation method is referred to as a QTV test). (3) Sulfur blackening in the contents repack was visually observed. The evaluation was performed by setting evaluation criteria as follows. ：: Good without blackening □: Light blackening is slightly seen only at the top of the can body Δ: Dark blackening is clearly seen at the top of the can ×: Dark blackening is seen over the entire can (4) The corrosion state in the contents repack was visually observed. The evaluation was performed by setting evaluation criteria as follows. ：: Good without corrosion □: Slight surface corrosion occurred △: Pitting corrosion reaching 1/4 to 1/3 of plate thickness ×: Pitting corrosion reaching 1/2 or more of plate thickness occurred

Examples 1-4 The thickness was 15 μm, the melting point was 232 ° C., and the intrinsic viscosity (IV) was
The point of 0.63 is the same for all, but the X-ray diffraction
780 cps thermoplastic polyester resin film
(No. 1), thermoplastic with X-ray diffraction intensity of 2580 cps
Polyester resin film (No.2), strong X-ray diffraction
3830 cps thermoplastic polyester resin fill
(No. 3), heat-resistant with X-ray diffraction intensity of 6800 cps
Four types of plastic polyester resin film (No. 4)
Films (raw material films corresponding to Examples 1-4, respectively)
Epoxy) with a number average molecular weight of 1600
Resin and polyester resin having a number average molecular weight of 1500
The number average molecular weight copolymerized at a weight ratio of 0:40 is 150.
100 parts by weight of epoxy-polyester copolymer resin
And an adhesive containing 5 parts by weight of phenolic resin,
15mg / dm ²Gravure roll
Cloth, hot air with adhesive dried at 130 ° C for 10 seconds
A plastic polyester resin film was prepared. At this time,
There was no shrinkage of the film. The above No.
1 to No. Using the film of No. 4, the plate thickness is 0.19 mm
And the amount of deposited metal Cr on one side is 110 mg / m², Its upper layer
15 mg / m in metal Cr conversion on one side²Hydration
Multiple heating of electrolytic chromic acid treated steel sheet with chromium oxide
Heated by passing between the rolls,
When the temperature reaches ℃, the polyester resin
Apply heat and pressure to both sides of the steel sheet so that the adhesive surface is in contact with the steel sheet.
4 types of film lamination corresponding to Examples 1-4
A steel sheet was prepared. Each laminate obtained
The steel sheet was good without wrinkles. Then the film
Print ink on one side of the laminated steel sheet and
ARCOAT (60mg / dm²) Done at 170 ° C for 10
After drying and baking in an electric oven, apply a processing lubricant.
Perform two drawing operations so that the oiled print surface is the outer surface of the can.
To form a drawn can having a drawn ratio of 1.92,
The can is heated in an electric oven at 200 ° C for 60 seconds.
Was.

The thus obtained Examples 1 to 4 (Nos. 1 to 4)
For the performance evaluation of the drawn can, the soundness of the polyester resin film film on the inner surface was examined by a QTV test, and the adhesion was examined by peeling the film by retort sterilization at 125 ° C. for 60 minutes. In addition, after repacking the contents from the commercially available canned tuna and canned boiled tuna in the above-mentioned squeezed can and tightening the can lid, a retort sterilization treatment was performed at 113 ° C. for 100 minutes to examine blackening of sulfurization and corrosion resistance. Was stored at 55 ° C. for one month and the corrosion state was examined. Example 1
Table 1 shows the contents of the thermoplastic polyester resin film performed in Steps 4 to 4, Table 2 shows the contents of the adhesive, and Table 3 shows the processing conditions.
Table 4 shows the performance evaluation results. From Table 4, Example 1,
The squeezed cans (Nos. 1, 2, 3, and 4) of Nos. 2, 3, and 4 did not peel off the film even after retort treatment and had good adhesion. It turns out that corrosion resistance is also good.

Examples 5 to 6 No. of the polyester resin film used in Example 1 1
And the thermoplastic polyester resin film used in Example 4 was coated with an adhesive according to the procedure of Example 1 (No. 5). Using a film (No. 6) on which an adhesive was applied according to the procedure of Example 1 and having a plate thickness of 0.22 mm and a Cr adhesion amount on one side of 25 mg / m ²
A 5T50 aluminum alloy plate treated with chromic phosphate is heated by passing it between a number of heating rolls, and when the plate temperature reaches 190 ° C., the adhesive surface is brought into contact with the aluminum alloy plate on both sides. It was thermocompression bonded to form a film-laminated aluminum plate. The obtained laminated aluminum plate was good without wrinkles.
Next, ink printing was performed on one surface of the film-laminated aluminum plate, and a clear coat was applied at 60 mg / d.
m ² is performed, after baking and drying at 10 min electric oven at 170 ° C., the processing lubricant to oiled printed surface becomes the outer surface of the can, by performing the two drawing, draw ratio is 1. After making 92 draw cans, the draw cans were placed in an electric oven for 200 hours.
Post-heating was performed at 60 ° C. for 60 seconds.

With respect to the performance evaluation of the drawn cans of Examples 5 to 6 obtained above, the soundness of the thermoplastic polyester resin film film on the inner surface was determined by a QTV test, and the adhesion was determined to be 12%.
It was examined by a retort sterilization treatment at 5 ° C. for 60 minutes. Also, after repacking the contents from the commercially available canned tuna flavored cans and boiled canned tuna in the above-mentioned squeezed cans and tightening the can lid, the retort sterilization treatment was carried out at 113 ° C for 100 minutes, and stored at 55 ° C for one month, and the corrosion resistance was reduced. Was examined. Table 1 shows the content of the thermoplastic polyester resin film performed in Examples 5 and 6, and Table 2 shows the content of the adhesive.
The processing conditions are shown in Table 3 and the performance evaluation results are shown in Table 4. From Table 4, the drawn cans of Examples 5 and 6 (Nos. 5 and 6) have good adhesion without film peeling even in the retort treatment, and have good corrosion resistance although they are repacks of the contents. You can see that.

Examples 7 to 8 A thermoplastic polyester resin film having a thickness of 25 μm, a melting point of 218 ° C., an intrinsic viscosity (IV) of 0.58 and an X-ray diffraction intensity of 1870 cps was coated on one surface with a number average molecular weight of 16
100 parts by weight of an epoxy-polyester copolymer resin having a number average molecular weight of 15,000 and 3 parts by weight of a melamine resin obtained by copolymerizing an epoxy resin having a number average molecular weight of 2500 and a polyester resin having a number average molecular weight of 2500 at a weight ratio of 60:40. Was applied with a gravure roll so as to have a dry thickness of 30 mg / dm ^2, and dried with hot air at 130 ° C. for 10 seconds to prepare a polyester resin film with an adhesive. At this time, no shrinkage of the film was observed. Using the obtained film, Ni having a plate thickness of 0.19 mm and one side of Ni having 500 mg / m ² , and an upper layer having hydrated chromium oxide having a single side of 15 mg / m ^{2 in} terms of metallic Cr in terms of metal Cr.
A plated steel sheet (No. 7) and, in Example 8, Sn plating having a hydrated chromium oxide having an attached amount of Sn of 1000 mg / m ² on one side and an upper layer having an attached amount of 15 mg / m ^{2 in} terms of metal Cr on one side. The steel sheet (No. 8) is heated by passing it between a number of heating rolls, and when the sheet temperature reaches 180 ° C., the polyester resin film with the adhesive is placed such that the adhesive surface is in contact with the steel sheet. Was thermocompression bonded to both sides to produce a film-laminated steel sheet.
The obtained laminated steel sheet was good without wrinkles. Next, ink printing was performed on one side of the film-laminated steel sheet, and a clear coat was further performed at 60 mg / dm ^2, followed by drying and baking in an electric oven at 170 ° C. for 10 minutes. After drawing twice to form an outer surface, a drawn can having a drawing ratio of 2.32 was prepared, and the drawn can was post-heated in an electric oven at 205 ° C. for 90 seconds.

With respect to the performance evaluation of the drawn cans of Examples 7 and 8 thus obtained, the soundness of the thermoplastic polyester resin film film on the inner surface was determined by a QTV test, and the adhesion was determined to be 12%.
It was examined by a retort sterilization treatment at 5 ° C. for 60 minutes. In addition, after repacking the contents of commercially available canned tuna flavored cans and boiled canned tuna in the above-mentioned squeezed cans and tightening the can lid, a retort sterilization treatment was performed at 113 ° C. for 100 minutes to examine sulfide black denaturation.
After storage at 55 ° C. for one month, the corrosion resistance was examined. Table 1 shows the contents of the thermoplastic polyester resin films performed in Examples 7 and 8.
Table 2 shows the contents of the adhesive, Table 3 shows the processing conditions, and Table 4 shows the performance evaluation results. From Table 4, the squeezed cans (Nos. 7 and 8) of Examples 7 to 8 have good adhesion without film peeling even in the retort treatment, and they are repacks of the contents but have no blackening of sulfide. It turns out that corrosion resistance is also good.

Examples 9 to 10 A thermoplastic polyester resin film having a thickness of 10 μm, a melting point of 243 ° C., an intrinsic viscosity (IV) of 0.72 and an X-ray diffraction intensity of 870 cps has a number average molecular weight of 900
Epoxy-polyester copolymer resin 18000 having a number average molecular weight of 18,000 obtained by copolymerizing an epoxy resin having a number average molecular weight of 5000 and a polyester resin having a number average molecular weight of 5000 at a weight ratio of 30:70.
An adhesive containing 00 parts by weight and 5 parts by weight of a melamine resin was coated with a gravure roll so as to have a dry thickness of 10 mg / dm ^{2 in} Example 9, and dried with hot air at 130 ° C. for 10 seconds. (No.
9) and in Example 10, the adhesive was applied with a gravure roll to a dry thickness of 45 mg / dm ^2, and dried with hot air at 130 ° C. for 10 seconds (No. 9). 10) was prepared respectively. At this time, no shrinkage of the film was observed. Using such a film obtained, a 5T50 aluminum alloy plate having a plate thickness of 0.22 mm and a Cr adhesion amount of 25 mg / m ² on one surface treated with chromic phosphate is passed through a number of heating rolls to heat the film. And
When the sheet temperature reached 190 ° C., the adhesive surface was thermocompression-bonded to both sides such that the surface of the adhesive was in contact with the aluminum alloy sheet, thereby producing a laminated aluminum sheet. The obtained laminated aluminum plate was good without wrinkles. Next, ink printing was performed on one surface of the laminated aluminum plate, and a clear coat (60 mg / dm ² ) was performed.
After drying and baking in an electric oven for 10 minutes, apply a lubricant for processing and perform drawing twice so that the printing surface becomes the outer surface of the can, and create a drawn can with a drawing ratio of 1.76. After that, the drawn can was post-heated in an electric oven at 200 ° C. for 30 seconds.

With respect to the performance evaluation of the drawn cans of Examples 9 to 10 thus obtained, the soundness of the polyester resin film film on the inner surface was examined by a QTV test, and the adhesion was examined by a retort sterilization treatment at 125 ° C. for 60 minutes. The contents of commercially available canned tuna and canned boiled tuna can be repacked in the above-mentioned squeezed can, and after tightening the can lid, a retort sterilization treatment is performed at 113 ° C for 100 minutes, and stored at 55 ° C for one month, and the corrosion resistance is reduced. Was examined. Table 1 shows the contents of the thermoplastic polyester resin films performed in Examples 9 to 10, Table 2 shows the contents of the adhesive, Table 3 shows the processing conditions, and Table 4 shows the performance evaluation results. From Table 4, the squeezed cans (Nos. 9 and 10) of Examples 9 to 10 have good adhesion without film peeling even in the retort treatment, and have good corrosion resistance although they are repacks of the contents. It turns out there is.

Example 11 For the inner surface of a can, the thickness was 15 μm, the melting point was 243 ° C., the intrinsic viscosity (IV) was 0.62, and the X-ray diffraction intensity was 2560 cp.
s thermoplastic resin film on one side, an epoxy resin having a number average molecular weight of 370 and a number average molecular weight of 15
An adhesive containing 100 parts by weight of an epoxy-polyester resin having a number average molecular weight of 16000 and 5 parts by weight of a melamine resin obtained by copolymerizing a 000 polyester resin at a weight ratio of 5:95 will have a dry thickness of 25 mg / dm ^2. Was applied with a gravure roll and dried with hot air at 130 ° C. for 10 seconds to prepare a polyester resin film with an adhesive. At this time, no shrinkage of the film was observed. In addition, for the outer surface side of the can, the thickness is 13 μm and the melting point is 225 ° C.
A white thermoplastic polyester resin film containing 20% by weight of a titanium oxide pigment was prepared, and the electrolytic chromic acid-treated steel sheet used in Example 1 was heated at a plate temperature of 210 ° C. and the film for the inner side of the can was an adhesive surface. The film for the outer surface of the can was thermocompression-bonded as it was so as to make contact with the steel sheet, thereby producing a film-laminated steel sheet (No. 11). The obtained laminated steel sheet was good without wrinkles on both sides. Next, ink printing is performed on the surface of the white thermoplastic polyester resin film on the outer surface side of the can of the laminated steel sheet, and a clear coat (very common clear is sufficient) is applied at 60 mg.
/ Dm ² and drying and baking at 170 ° C. for 10 minutes in an electric oven, then applying a working lubricant, and performing drawing twice so that the printing surface becomes the outer surface of the can. .7
After preparing the drawn cans, the drawn cans were placed in an electric oven for 2 hours.
Post-heating was performed at 00 ° C. for 60 seconds.

Regarding the performance evaluation of the drawn can thus obtained,
The soundness of the thermoplastic polyester resin film film on the inner surface was determined by a QTV test, and the adhesion was evaluated by peeling the film by retort sterilization at 125 ° C. for 60 minutes. Similarly, the contents of commercially available canned tuna and canned boiled tuna can be repacked in the above-mentioned squeezed can, and the can lid is tightly wound.
The mixture was subjected to a retort sterilization treatment at 100 ° C. for 100 minutes to examine blackening by sulfide, and the corrosion resistance was stored at 55 ° C. for 1 month to examine the corrosion state. Table 1 shows the contents of the polyester resin film performed in Example 11, and Table 2 shows the contents of the adhesive.
The processing conditions are shown in Table 3, and the performance evaluation results are shown in Table 4. Table 4
Therefore, the drawn can (No. 11) of Example 11 had good adhesion without peeling of the film on the inner and outer surfaces of the can even in the retort treatment, and it was a repack of the contents but no blackening of sulfide. It shows that the corrosion resistance is also good

Examples 12 to 13 An epoxy resin having a number average molecular weight of 370 and a number average molecular weight of 50 were provided on both sides of the electrolytic chromic acid-treated steel sheet used in Example 1.
An adhesive containing 100 parts by weight of an epoxy-polyester resin having a number average molecular weight of 15,000 and 10 parts by weight of a melamine resin obtained by copolymerizing a polyester resin of No. 00 at a weight ratio of 90:10 becomes 20 mg / dm ² as a dry thickness. After coating with a gravure roll and drying with hot air at 130 ° C., the plate is subsequently heated in a hot air oven at a plate temperature of 175 ° C.
μm, melting point: 243 ° C., intrinsic viscosity (IV): 0.62,
A thermoplastic polyester resin film having an X-ray diffraction intensity of 2780 cps and a white thermoplastic polyester resin film containing the titanium oxide pigment used in Example 11 were pressed on the other surface with a laminating roll to obtain a film of Example 12. A laminated steel sheet (No. 12) was prepared.

Similarly, both the electrolytic chromic acid treated steel sheets
On the surface, an epoxy resin with a number average molecular weight of 2700 and a number average
A polyester resin having a molecular weight of 1000 is weighed 40:60.
Epoxy having a number average molecular weight of 10,000 copolymerized at a quantitative ratio
100 parts by weight of polyester resin and 5 parts of melamine resin
20 parts per million by weight of the adhesive containing parts by weight ²
Apply with a gravure roll so that it becomes hot air at 130 ° C
After drying, it was heated in a hot air oven and the plate temperature was 180 ° C.
One side of a double sided adhesive coated electrolytic chromic steel sheet
Put the thermoplastic polyester resin film of the above on the other side
White thermoplastic polyester containing the above titanium oxide pigment
Compression bonding of the resin film with a laminating roll
The film laminated steel sheet (No. 13) of Example 13 was made.
Done.

Next, ink printing was performed on the surface of the white thermoplastic polyester resin film on the outer surface side of the cans of the laminated steel sheets (Nos. 12 and 13) of Examples 12 and 13 obtained above, and further a clear coat (60 mg / dm. ² ) Do it,
After drying and baking in an electric oven at 170 ° C. for 10 minutes, lubricating with a processing lubricant is performed so that the printing surface becomes the outer surface of the can.
The drawing can was performed twice to prepare a drawn can having a drawn ratio of 1.76, and the drawn can was post-heated at 200 ° C. for 60 seconds in an electric oven.

With respect to the performance evaluation of the drawn cans of Examples 12 and 13 thus obtained, the soundness of the thermoplastic polyester resin film film on the inner surface was evaluated by a QTV test, and the adhesion was evaluated by retort sterilization at 125 ° C. for 60 minutes. The state of peeling was examined. In addition, similarly, after repacking the contents of commercially available canned tuna and canned boiled tuna in the above-mentioned squeezed can and tightening the can lid, a retort sterilization treatment was performed at 113 ° C. for 100 minutes, and black sulfide sulfation was examined. 55 for corrosion resistance
C. for one month and examined for corrosion. Examples 12-1
Table 1 shows the contents of the polyester resin film used in Table 3, Table 2 shows the contents of the adhesive, Table 3 shows the processing conditions, and Table 4 shows the performance evaluation results. From Table 4, the drawn cans of Examples 12 and 13 (Nos. 12 and 13) did not peel off the film on the inner and outer surfaces of the can even after retort treatment, had good adhesion, and were repacks of the contents. It turns out that there is no blackening of sulfurization and the corrosion resistance is good.

Comparative Examples 1-2 The film Nos. The aperture ratio obtained from 1 is 1.92.
Drawn can (No. 14) and film N of Example 4
o. With respect to the drawn can (No. 15) obtained from No. 4, Comparative Example 1 (No. 14) and Comparative Example 2 (N
o. 15). These were subjected to a retort sterilization treatment at 125 ° C. for 60 minutes, and the adhesion was examined. Table 1 shows the contents of the polyester resin films used in Comparative Examples 1 and 2.
Table 2 shows the contents of the adhesive, Table 3 shows the processing conditions, and Table 4 shows the performance evaluation results. From Table 4, Comparative Example 1 of the present invention,
It can be seen that the squeezed cans of No. 2 (Nos. 14 and 15) suffered film peeling during the retort treatment and were inferior in adhesion to the examples. The drawn cans of Comparative Examples 1 and 2 (N
o. In Nos. 14 and 15), the corrosion resistance was not evaluated by repacking the contents because of poor adhesion.

Comparative Example 3 The adhesive used in Example 1 was applied to one surface of a thermoplastic polyester resin film having a thickness of 25 μm, a melting point of 243 ° C., an intrinsic viscosity (IV) of 0.48, and an X-ray diffraction intensity of 530 cps. Was applied with a gravure roll to a dry thickness of 20 mg / dm ^2, and dried with hot air at 130 ° C. for 10 seconds to prepare a polyester resin film with an adhesive. At this time, the film shrunk and fine wrinkles occurred. Next, the electrolytic chromic acid-treated steel sheet used in Example 1 was heated by passing it between a number of heating rolls,
When the sheet temperature reached 180 ° C., the steel sheet was thermocompression-bonded to both sides of the steel sheet such that the adhesive surface was in contact with the steel sheet, thereby producing a film-laminated steel sheet (No. 16). At this time, the laminated steel plate had small wrinkles particularly at the edge of the film. Next, ink printing was performed on one surface of the film-laminated steel sheet, and a clear coat was further performed at 60 mg / dm ² .
After drying and baking in an electric oven at 0 ° C. for 10 minutes, a working lubricant is applied and drawn twice so that the printed surface becomes the outer surface of the can, and the drawn can has a drawing ratio of 1.76. Was prepared, the drawn can was post-heated in an electric oven at 200 ° C. for 60 seconds.

Regarding the performance evaluation of the drawn can thus obtained,
The soundness of the thermoplastic polyester resin film film on the inner surface was examined by a QTV test, and the adhesion was examined by a retort sterilization treatment at 125 ° C. for 60 minutes. In addition, similarly, after repacking the contents of commercially available canned tuna and canned boiled tuna in the above-mentioned squeezed can and tightening the can lid, a retort sterilization treatment was performed at 113 ° C. for 100 minutes, and black sulfide sulfation was examined. And stored at 55 ° C. for 1 month to examine corrosion resistance. Table 1 shows the contents of the thermoplastic polyester resin film obtained in Comparative Example 3, Table 2 shows the contents of the adhesive, Table 3 shows the processing conditions, and Table 4 shows the performance evaluation results. From Table 4, it can be seen that the drawn can of Comparative Example 3 of the present invention (N
o. 16) shows that the adhesiveness is good, but the content repack test shows that the sulfuration blackening property and the corrosion resistance are inferior to those of the examples. Further, as described above, it can be seen that the laminated steel sheet is inferior in laminating properties, such as small wrinkles particularly at the edge of the film.

Comparative Examples 4 and 5 Adhesion used in Example 1 to one surface of a thermoplastic polyester resin film having a thickness of 25 μm, a melting point of 243 ° C., an intrinsic viscosity (IV) of 0.72, and an X-ray diffraction intensity of 7520 cps. The agent was applied with a gravure roll to a dry thickness of 20 mg / dm ^2, and dried with hot air at 130 ° C. for 10 seconds to prepare a thermoplastic polyester resin film with an adhesive. At this time, no shrinkage of the film was observed. The thus-obtained thermoplastic polyester resin film with an adhesive was heated by passing between a number of heating rolls using the electrolytic chromic acid-treated steel sheet used in Example 1, and when the sheet temperature reached 180 ° C. The thermoplastic polyester resin film with the adhesive was thermocompression-bonded to both sides of the steel sheet such that the adhesive surface was in contact with the steel sheet, thereby producing a film-laminated steel sheet (No. 17). The obtained laminated steel sheet was good without wrinkles. Similarly, the aluminum alloy plate used in Example 2 was heated by passing it between a number of heating rolls, and the plate temperature was 180 ° C.
At this point, the aluminum alloy plate was thermocompression-bonded to both surfaces of the aluminum alloy plate so that the adhesive surface was in contact with the aluminum alloy plate, thereby producing a laminated aluminum alloy plate (No. 18).
At this time, no shrinkage of the film was observed. Next, ink printing is performed on one surface of the laminated steel plate and the laminated aluminum alloy plate, and further a clear coat (60 mg / dm ² ) is performed. The resultant is dried and baked in an electric oven at 170 ° C. for 10 minutes, and then a working lubricant is applied. The drawing can is performed twice so that the oiled print surface becomes the outer surface of the can, and a drawn can having a drawing ratio of 1.76 is prepared. Then, the drawn can is post-heated in an electric oven at 200 ° C. for 90 seconds. Was done.

With respect to the performance evaluation of the drawn cans of Comparative Example 4 (No. 17) and Comparative Example 5 (No. 18), the adhesion was examined by a retort sterilization treatment at 125 ° C. for 60 minutes.
Table 1 shows the contents of the thermoplastic polyester resin films obtained in Comparative Examples 4 and 5, Table 2 shows the contents of the adhesive, Table 3 shows the processing conditions, and Table 4 shows the performance evaluation results. From Table 4, the drawn cans of Comparative Examples 4 and 5 of the present invention (Nos. 17 and 18)
It can be seen that the film was peeled by the retort treatment, and the adhesion was inferior to that of the examples. In addition, Comparative Example 4 of the present invention,
Since the drawn cans of No. 5 (Nos. 17 and 18) had poor adhesion, the corrosion resistance of the repacked contents was not evaluated.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

[Table 3]

[0075]

[Table 4]

[0076]

As described above, according to the drawn can of the present invention, since the inner surface is laminated with a thermoplastic polyester resin film, a drawn can having better corrosion resistance than a conventional painted can can be obtained. Furthermore, since the polyester resin film is also applied to the outer surface, it has smoothness, so that the print applied to the upper layer has sharpness, so that a drawn can with a beautiful printed appearance can be obtained compared to the conventional print can. be able to. In addition, the thermoplastic polyester resin film on the inner surface of the squeezed can of the present invention is safe because bisphenol A and other endogenous endocrine disrupting chemicals (environmental hormones) are not used as a raw material. It is a squeezed can for food cans that can meet the requirements.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65D 1/09 B65D 1/28 1/28 1/00 B (72) Inventor Eiji Fujishige Nishi, Sagamihara-shi, Kanagawa 5-5-1 Hashimoto Inside the Technology Development Center, Daiwa Seikan Co., Ltd. (72) Inventor Tomohiko Hayashi 5-5-1 Nishihashimoto, Sagamihara City, Kanagawa Prefecture Inside the Research Laboratory, Daiwa Seikan Co., Ltd. (72) Hiroshi Hasegawa F-term (reference) in Sakuranomiya Chemical Co., Ltd. 3-1-2-3 Nakano-cho, Miyakojima-ku, Osaka-shi, Osaka CA13A CA13B CA13D CB00B DA01 GB16 GB23 HB31E JA04A JA07B JA20 JB02 JB16A JB16D JN01E

Claims (4)

[Claims] In a drawn can (including a deep drawn can) obtained by a single drawing process or a plurality of drawing processes by press-forming a metal plate, at least a metal surface on the inner surface side of the can is provided with (A) There is an adhesive layer and (B) a thermoplastic polyester resin film layer, and the adhesive layer of (A) is
(A) an epoxy resin having a number average molecular weight (Mn) of 340 to 10,000, and (b) a number average molecular weight (Mn) of 1000
A polyester resin having a number average molecular weight (Mn) of 6000 to 300 obtained by copolymerizing a polyester resin having a weight ratio of epoxy resin to polyester resin of 95: 5 to 5:95.
100 parts by weight of an epoxy-polyester copolymer resin of No. 00, and 0.5 to 20 parts by weight of a curing agent, and a dry thickness of 5 to 5 parts.
50 mg / dm ² , and the thermoplastic polyester film (B) has a thickness of 8 to 30 μm and a melting point (T
m) The intensity of the highest peak among peaks detected at a temperature of 210 ° C. or higher and 2θ of 22 ° to 28 ° measured by X-ray diffraction is in the range of 700 cps to 7000 cps, and (A) and (A). The metal sheet covered with B) is formed into a final can body with a draw ratio of 1.5 to 2.5 as a draw ratio, and the strain in the thermoplastic polyester resin film layer is released by the forming processing. A film laminated squeezed can characterized in that: 2. A thermoplastic polyester resin film layer / ink layer / clear coat layer is directly coated on a metal plate by thermocompression bonding from the metal side on the outer surface side of the drawn can, or the adhesive of (A) is applied. 2. The drawn can for a film laminate according to claim 1, which is coated with an agent layer. 3. The thermoplastic polyester resin film layer coated on the inner surface and the outer surface of the can has a colorant of 5%.
3. The composition according to claim 1, wherein the content is about 20% by weight.
2. The film-laminated squeezed can according to 1. 4. The film-laminated drawn can according to claim 1, wherein the adhesive layer contains a white pigment.