JPH09277453A - Film laminated on metal plate, laminated metal plate, and metal container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a decorative metal plate which is clear and beautiful, has high paper feeling, and is suitable for can molding by specifying an abrasion resistance index of a cured heat resistant layer and the number of pinholes in a laminated film. SOLUTION: A film laminated on a metal plate in which in a laminated film in which a transparent cured heat resistant layer is formed on one side of a thermoplastic resin layer, an abrasion resistance index of the surface of the cured heat resistant layer evaluated by a general method is not exceeding 1.2%, and the number of pinholes whose diameter is at least 0.1mmϕ is not exceeding 0/1.000m<2> . The thermoplastic resin film is clear and makes beautiful multiple printing possible, and a thermoplastic resin film having a proper flexibility so that bending, etc., can be done easily in can making process after lamination is used. Besides, the thickness of the cured heat resistant layer is 0.3-10g/m<2> , more preferably 0.3-5g/m<2> .

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a laminating film used for heat resistance, cosmetics and rust prevention of metal can materials such as soft drinks, beer and canned foods, and a laminated metal plate laminated with the film, The present invention relates to a metal container formed by forming the laminated metal plate into a can shape.

[0002]

2. Description of the Related Art Metal plates such as steel and aluminum are mainly used as can materials for various soft drinks, beers, cans, and the like. Printing and coloring are applied. The method of printing and coloring these containers that is currently in practical use is a method in which a metal plate is slit into a predetermined size and then printed by offset printing or the like and then printed.
Alternatively, it is a method of performing bending and processing into a cylindrical shape after slit processing, performing seam welding, and then performing printing and baking by offset printing or the like. Then, a metal container is obtained by performing flange processing, inside coating and baking, seaming processing, and the like.

[0003]

However, in the method of printing directly on a metal material, whether printing is performed in a flat plate shape or in a method of printing after forming into a cylindrical shape, a metal material such as gravure printing is used. A printing method using an intaglio printing cannot be adopted. This is because the metal material is hard and it is extremely difficult to make the metal intaglio uniformly contact the entire printing surface. Therefore, in the past, a plate having elasticity such as a rubber plate or a flexible resin plate has been used, but the printing accuracy when using such an elastic intaglio is poor, and it is difficult to obtain clear printing. In addition, it is difficult to perform complicated printing that requires a wide range of gradation settings such as halftone printing and photographic printing, and in reality, only extremely monotonous printing and coloring are performed. To achieve more beautiful and three-dimensional printing, multiple printing with multiple paints is required. However, it takes a long time to dry and bake the printing ink, so such multiple printing Incorporation into the can manufacturing process also causes a problem that the drying and baking of the printing ink becomes the rate-determining factor and the can manufacturing speed becomes extremely slow. Therefore, the number of overprints that can be practically used on an industrial scale is naturally limited, and printing with satisfactory sharpness and aesthetic design cannot be obtained.

Although a method of offset printing on a slit metal plate is also known, halftone printing and the like are still difficult, and printing with satisfactory sharpness and aesthetic design cannot be obtained. Then, it is similar to the case of the gravure printing. As a method of solving the above problems, a method of laminating a film having a trademark design printed on a metal plate has been proposed (for example, JP-A-4-29).
2942).

As the laminated film for the metal plate, a thermoplastic resin film is generally used, and the thermoplastic resin film by heat is applied by seam welding during can making, heat treatment after enclosing the contents, retort treatment, or the like. A hardening heat-resistant layer is provided for the purpose of suppressing softening and whitening. Further, the cured heat resistant layer also has a function of preventing scratches in each process including the can making process and imparting plate passing property. For example, in JP-A-5-11979, the cured heat resistant layer has a static friction. It has been proposed that it is preferable to have the characteristic that the coefficient is 0.2 or less. Certainly, by improving the slipperiness of the cured heat-resistant layer, it is possible to improve the stripability and scratchability, but just by improving the slipperiness of the cured heat-resistant layer, for example, the scratchability is not sufficient, Due to scratches on the surface of the cured heat-resistant layer that occurred during the can manufacturing process and food filling process, the sharpness of trademark printing, which is one of the major characteristics of the method that uses a printing film, is partially obstructed, satisfying high-level market requirements. I couldn't. Furthermore, when a thermoplastic resin film is laminated on a metal plate, that is, when the thermoplastic resin film is laminated on a metal plate and the laminated metal plate is used for a metal can, the film has pinholes (holes). In that case, a corrosion phenomenon occurs in the metal can material, and the sharpness and the aesthetic design of the trademark printing are significantly impaired, which has a great adverse effect. The present invention has been made in view of the above circumstances, and by laminating it on a metal plate, it is possible to obtain a beautiful and beautiful decorative metal plate having a high paper feel, and is free from pinholes. The present invention is to provide a laminating film having excellent corrosion resistance of a metal can material, a metal plate laminated with the film, and a cosmetic metal container formed by molding the metal plate into a can shape.

[0006]

In a laminated film having a substantially transparent cured heat-resistant layer provided on at least one surface of a thermoplastic resin film, the abrasion resistance of the surface of the cured heat-resistant layer evaluated by the method defined in the text. The index is 1.2% or less, and the number of pinholes with a diameter of 0.1 mmφ or more is 0 /
A film for laminating on a metal plate, which is 1,000 m ² or less.

In the present invention, it is a preferred embodiment to use a polyester film as the thermoplastic film. In the present invention, the diameter is 0.1 mm.
Preferably the number pinholes or φ is 0 Ke / 10,000 m ² or less, a more preferred embodiment is that the number pinholes or more in diameter 0.1mmφ is 0 Ke / 100,000 m ² or less. Further, in the present invention,
It is a preferred embodiment that the number of pinholes is detected by a pinhole detector using a high voltage application method. The present invention also includes a laminated metal plate in which the cured heat resistant layer is laminated on the metal plate on the side opposite to the metal plate. In the present invention, a laminated metal plate is used, and a metal container molded with the laminated layer on the outside is also included.

Here, the thermoplastic resin film is a thermoplastic resin having an appropriate degree of flexibility so that clear and beautiful multiple printing can be performed and bending processing etc. can be easily performed at the time of can making processing after lamination. Film is used. However, this thermoplastic resin film has a melting point of 175 so as to withstand heat received during seam welding during can making, inside coating after can making, boiling process after sealing the contents, or subsequent retort treatment. If the melting point is too low, pinhole defects may occur due to heating during the inside coating process, or the film may melt or soften and shrink to lose smoothness or gloss. In addition, the film tends to have defects such as blister-like irregularities, stress cracks, and delamination. From this point of view, the more preferable thermoplastic resin film has a melting point of 160 ° C. or higher, and specific preferred examples thereof include polyester resin, polypropylene resin, polymethylpentene-1, polycarbonate, polyimide, PPS, PE
Examples of the film include K, PEEK and the like or various modified resins thereof. Above all, a polyester resin film is recommended as a particularly preferable film in view of the balance between heat resistance and economy.

The constituent material of the cured heat-resistant layer used in the present invention is substantially transparent and has a melting point or decomposition temperature of 25.
It is preferable to use one having a temperature of 0 ° C. or higher, and more preferably 300 ° C. or higher. For example, a silicone type, an epoxy type, a melamine type, a urea type, an acrylic type, a urethane type, an unsaturated polyester type, an alkyd type, an oxazoline type or the like. Various curing-reactive resins such as various modified resins can be used. These curing reactive resins may be a single component, or may be a mixture of two or more kinds.
The use of two or more blends is especially recommended. For the purpose of improving the slipperiness of the surface of the cured heat-resistant layer, additives such as silicone compounds, fluorine compounds, and various waxes containing higher hydrocarbon chains having lubricity may be added to the curing-reactive resin layer. This is a preferred embodiment. For the same purpose as above, it is also a preferred embodiment to mix fine particles of organic or inorganic.

The thickness of the cured heat resistant layer is 0.3 to 10 g /
m ² , more preferably 0.3 to 5 g / m ² . If it is too thin, the surface protection effect is not sufficiently exerted, while if it is too thick, cracks tend to occur in the cured heat-resistant layer during bending. In the present invention, it is preferable to perform printing on the surface opposite to the above-mentioned cured heat-resistant layer in order to enhance the sharpness and aesthetic design of trademark printing. Therefore, the above-mentioned cured heat-resistant layer needs to be substantially transparent. Therefore, it is necessary to pay attention to the addition amount of the lubricant and fine particles to be added to the constituent material of the cured heat resistant layer, as well as to select components that do not reduce the transparency. In the present invention, the abrasion resistance index of the surface of the cured heat-resistant layer, which is evaluated by the method defined in the text, is preferably 1.2% or less.
1.0% or less is preferable, and 0.8% or less is more preferable.

If the abrasion resistance index exceeds 1.2%, the surface of the cured heat-resistant layer is scratched in the can making process and the food filling process, the sharpness of trademark printing is deteriorated and the commercial value is reduced, which is not preferable. . The means for setting the abrasion resistance index to 1.2% or less is not particularly limited, but it is preferably controlled by controlling these factors because it is largely controlled by the composition and curing degree of the constituent material of the cured heat resistant layer. It is an embodiment. Also,
The thickness of the cured heat resistant layer is also an important factor.

The method for forming the cured heat resistant layer is not particularly limited, but a so-called coating method in which a curable resin is dissolved in a solvent, coated on a thermoplastic resin film, and dried and cured is a preferred embodiment. Also, the curing reaction is not particularly limited. Various energy sources such as heat, electron beams, ultraviolet rays and X-rays can be used. Utilization of heat or electron beam is a preferred embodiment from the viewpoint of economy. When the coating method and the thermosetting method are used, the abrasion resistance index is greatly affected by the drying conditions and the curing conditions.
It is an important factor of the means to keep the percentage below. In the case of the method,
A preferred embodiment is a two-step heating method including a drying step and a curing step. The curing step requires high temperature and efficient heating, and infrared heating is the preferred embodiment. The temperature of each step in the case of the two-step heating method should be appropriately selected depending on the composition of the curable resin, the drying step, the furnace length of the curing step, etc. In general, the drying step is performed at 140 ° C. or lower. Is preferably carried out at 140 ° C. or higher.

Further, in order to obtain a uniform cured layer, the selection of the solvent at the time of coating and the amount of the residual solvent before starting the curing step are also important factors. On the other hand, in order to achieve the above-mentioned object, the present inventors set the size of the pinhole as 0.1 mmφ.
I found that this should not happen. That is, 0.1
In the case of a pinhole of less than mmφ, for example, when laminating by thermocompression bonding to a metal plate, a minute dimensional change phenomenon due to the heat history of the film may result in blocking the pinhole that existed immediately before laminating, The rust-preventive property of the metal can material because the minute flow phenomenon due to the heat history at the time of laminating the adhesive and / or the adhesive layer existing between the film and the metal plate closes the pinholes existing until just before the lamination. Has been found to be sustainable. Further, in order to achieve the above-mentioned object, the number of pinholes having a diameter of 0.1 mm or more must be 0 / 1,000 m ² or less. 0 / 10,000 m ² is preferable, 0 / 100,000
m ² is more preferred, and 0 / ∞m ² is the most preferred embodiment.

In order to achieve the above-mentioned object, it is necessary to sufficiently dry the raw material for film production during the production of the thermoplastic resin film. For example, when a polyester resin is used as the thermoplastic resin. If so, the water content in the raw material must be 50 ppm or less.
If it exceeds 50 ppm, air bubbles are mixed in during the film production process, and the air bubbles are destroyed during the subsequent processing steps to become pinholes, which is not preferable. Also,
In the production of a thermoplastic resin film, it is necessary to sufficiently remove resin deterioration products and other contamination components in the resin melting step for forming into a film shape. For example, at least one place in the step. It is necessary to introduce a site having a filter function as described above. When a thermoplastic resin film is manufactured using a resin melting process that does not have a part with a filter function, foreign matter such as contaminants form bubbles as cores in the film, and bubbles containing this foreign matter as described above are generated. However, it is not preferable because it will be destroyed and become a pinhole as it goes through the various processing steps thereafter.

Further, the manufacturing process of the thermoplastic resin film for laminating on the metal plate is always in a clean state,
That is, it is necessary to take care so as to keep the floating foreign matter on the surface of the film or to be attached thereto. When a large amount of floating foreign matter is present in the manufacturing process of the film, the floating foreign matter gets on or adheres to the film, and for example, the floating foreign matter is rolled up together with the film in the film winding step, and the film during film winding It is not preferable because floating foreign matter will make holes in the film due to the tension and / or the pressure contact force, resulting in pinholes. On the other hand, in order to achieve the above-mentioned object, it is necessary to inspect the quality of the film to be a product by using a pinhole detector described later and to classify the product according to the number of pinholes present.

The method of laminating the above-mentioned film for laminating on a metal plate to a metal plate is not particularly limited, and a dry laminating method or a thermal laminating method can be preferably used. It is a preferred embodiment that a curable resin is used so that it is firmly bonded to a metal plate and the bonding force is not lost by seam welding during can making and subsequent boiling or retort treatment. Specific examples thereof include epoxy resin, polyurethane resin, polyester resin, polyester polyurethane resin and the like, or various modified resins thereof. These are usually applied to a laminating film by a coating method and partially cured to a metal plate. It is better to combine it with and completely cure it during lamination.

For laminating on the metal plate, it is necessary to laminate the laminating film so that the cured heat-resistant layer of the laminating film faces the metal plate. When the laminating film thus obtained is laminated on a metal plate, it is beautiful and has excellent abrasion resistance on the surface of the laminated metal plate. It can be used as it is for various panel materials and cosmetic outer plate materials. Not only can it be used as a metal container, but when it is made into a can according to a conventional method with the laminate layer as the outside, an extremely beautiful and highly designed metal container can be obtained.

Further, the pinhole detector according to the high voltage application method is used to detect the pinhole. With this method, all the pinholes having a diameter of 0.1 mmφ or more can be detected, and the pin diameter exceeding 0.01 mmφ can be detected. It is a preferred embodiment that all holes can be detected. FIG. 1 shows an example of a high voltage application type pinhole detector according to the present invention. The film sample roll wound into a roll attached to the unwinding shaft portion 1 is unwound toward the guide roller 2 and runs.
When the film travels between the detection section roller in the next 3 and the detection electrode 4 set above it, if a pinhole exists in the film, a discharge phenomenon occurs from the detection electrode, The high voltage generator and the pinhole detection data processor detect the presence of pinholes. After that, the film is 5 guide rollers and 6
It travels between the pressure contact rollers of (1) and is wound on the core attached to the winding shaft of (7). Such a pinhole detector may be installed online or offline for the film manufacturing process, but online installation is a more preferable embodiment.

EXAMPLES Next, the present invention will be described more specifically with reference to Examples.
The present invention is of course not limited by the following implementations, and any modification and implementation within the scope of the above-mentioned gist is included in the technical scope of the present invention. In the examples, “parts” means “parts by weight”, and “%” means “% by weight”. Each measurement item followed the following method. (1) Abrasion resistance evaluation method Cardboard (JIS Z1516 standard “Double-sided corrugated board 3
The sample film is adhered and fixed with cellophane tape, with the heat-resistant layer side as the surface, on the board cover of "Seed"). on the other hand,
16 pieces of gauze are piled up on the spherical head side of a 2 pound hammer and fixed. The gauze mounting part of the hammer to which the gauze is fixed is immersed in methyl ethyl ketone for 10 seconds. After stopping the immersion and allowing methyl ethyl ketone to fall naturally, shake the hammer twice in the vertical direction and shake off excess methyl ethyl ketone. The surface of the sample fixed on the cardboard is held by a 2-pound hammer containing the methyl ethyl ketone in the gauze portion at the end of the handle of the hammer, the length of 160 cm is fixed by a ruler, and the blade is reciprocated 100 times at a speed of 2 seconds / reciprocation. .
The weight is applied only to the weight of the hammer, and the force is applied only to the reciprocation of the hammer. Replace the gauze every time. The haze of the film is measured to determine the degree of scratches on the part of the sample where the hammer is reciprocated. That is, the difference in haze value (%) between the reciprocated portion and the other portion was used as a measure of wear resistance. The haze value was measured with a haze meter manufactured by Toyo Seiki in an area of 6 mmφ. The measurement place was shifted and it displayed as the average value of the measured value measured 20 times.

(2) Static Friction Coefficient of Film The static friction coefficient between the surfaces of the cured heat-resistant layers is ASTM-D-18.
It measured according to 94. (3) Pinhole detection method (high voltage application method) Using the device as shown in FIG. 1, the gap between the detection electrode and the detection roller is 0.2 mm, applied voltage setting is 2.4 kV,
Running speed 50 m / min. Width of 1,000 mm,
A film sample roll wound in a roll shape having a length of 1,000 m was subjected to running / detection inspection. In addition, pinholes of various sizes were preliminarily produced in the film roll sample in the unwinding portion by using a sharp needle, and detection inspection was conducted by the same method. As a result, the pinhole detector of the present invention has a diameter of at least 0. It has been found that a pinhole of 0.01 mmφ or more can be detected.

(4) Method for producing a laminated metal plate (laminated steel plate) An adhesive (a mixture of a polyurethane adhesive "Adcoat" and a curing agent manufactured by Toyo Ink Co., Ltd. and a curing agent) was applied to the corona surface of the film sample in an amount of 4 g / solid. m ² coating, dried and aged at 40 ° C. for 24 hours to obtain a laminating film. This laminating film was laminated on a degreased cold-rolled steel sheet by a thermal lamination method to obtain a laminated steel sheet.

(5) Anticorrosion Test Method After obtaining a laminating film inspected according to the inspection method of (3), a laminated metal plate is produced according to the method of (4), and this is subjected to a can-making step. Molded into a metal container. Fill the can with 1% NaCl solution,
After one month, rust was observed and the can was visually inspected. In addition, as a reference example, pinholes of various sizes were formed in the film sample by the same method as the method of forming pinholes using the sharp needle in the method (3) described above, and the method (2) above was used. Therefore, individual laminated metal sheets were obtained. On the other hand, similar laminated metal plates were prepared for the film small sample without pinholes, and these laminated metal plates were respectively immersed in a 1% NaCl aqueous solution, and rust was observed after 1 month and appearance of the laminated metal plate. The inspection was carried out.

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.80 (glass transition point: 65 ° C.) and polyethylene terephthalate-polytetramethylene glycol ether block copolymer were contained as polytetramethylene glycol ether components. A film having a thickness of 12 μm (200 ° C.) obtained by blending so as to be 4% by weight, forming a film and biaxially stretching
Shrinkage stress in 0.5 kg / mm ² ) on one side, bisphenol A type epoxy resin 50 parts, polyester resin 35 parts, hexamethoxymethylol melamine 15
Part, silicone resin 1 part, p-toluenesulfonic acid 0.
Thickness after drying a coating solution obtained by dissolving a cured heat-resistant resin composition consisting of 7 parts, polyethylene wax 0.2 part and fluororesin 0.2 part in a solvent containing methyl ethyl ketone / ethyl acetate / toluene as a main component by a gravure roll method. The coating was applied so that the coating temperature was 1 g / m ² and the cured heat-resistant layer treated at a drying temperature of 95 ° C. and a curing temperature of 180 ° C. was laminated to obtain a laminated film. The drying process was performed with hot air, and the curing process was performed with infrared light. The residual solvent after the drying process is 10
It was 0 ppm. Corona treatment was applied to the opposite surface of the cured heat-resistant layer.

The abrasion resistance index and static friction coefficient of the laminated film were 0.1% and 0.11. The number of detected pinholes with a diameter of 0.1 mmφ or more is 0/20,
It was 000 m ² . The laminated film obtained in this example is
The slipperiness and wear resistance were excellent, and the number of pinholes was small. After printing on the corona surface of the laminated film, an adhesive is coated on the printing ink layer and dried at 40 ° C. according to the method of (4) above.
Aged for 24 hours to obtain a laminating film. Thereafter, this laminating film was laminated on a degreased cold-rolled steel sheet by a thermal lamination method to obtain a laminated steel sheet. When a metal container for soft drinks was created by a conventional method using this laminated steel plate,
The resulting laminated surface of the body part of the container had a beautiful appearance that was clear and rich in gloss, and had excellent gloss. In the above can-making step, heat is applied to the laminating film at a temperature of 270 ° C. or higher, which seems to soften the polyethylene terephthalate layer of the film slightly, but it is protected by a cured heat-resistant layer made of an epoxy-modified urea resin. As a result, shrinkage deformation, deterioration of gloss, and alteration of the printing ink layer were hardly observed. The container was treated with hot water at 100 ° C. and steam at 125 ° C., but no turbidity or thermal deterioration of the laminating film layer was observed, and the beautiful appearance was not impaired. Also, there is no scratch on the surface of the laminated film due to rubbing during the transfer of the laminated pieces of the laminated steel sheet in the can making process, or rubbing due to contact between the cans in the can making process or food filling process, and it is clear and glossy. It had a rich and beautiful appearance and was highly practical. Further, a test for rust generation was carried out on the laminating film by the method (5). As a result, the number of rusted cans was 0 / 1,000,000, and the appearance of all the cans was maintained in a beautiful state, and the film had high commercial value.

COMPARATIVE EXAMPLE 1 Except that the drying temperature is 80 ° C. and the curing temperature is 135 ° C.,
The same laminated film as in Example 1 was obtained. The residual solvent amount after the drying step was 600 ppm. The abrasion resistance index of the laminated film was 1.5%. The coefficient of static friction is 0.11, and the number of pinholes with a diameter of 0.1 mm or more is 0.
KE / 20,000 m ² . The laminated film obtained in this Comparative Example had good slipperiness and a small number of pinholes, but poor abrasion resistance. Using the laminated film, a laminated steel plate and a metal container were obtained in the same manner as in Example 1. The laminated steel sheet and metal container obtained in this comparative example are inferior in abrasion resistance of the cured heat-resistant layer surface of the laminated film, and the laminated film surface is partially scratched in the can making process or the food filling process, resulting in poor cosmetic appearance. However, the product value was low.

Comparative Example 2 Number of detected pinholes having a diameter of 0.1 mm or more, 1 /
The same laminated film as in Example 1 was obtained except that the thickness was 1,000 m ² , a metal plate was obtained, and a metal container was obtained. As a result, the number of rusted cans was 1 / 50,000, and the presence of pinholes was confirmed in the defective cans. As described above, the film had a low commercial value because rust was generated in the metal can material due to the presence of pinholes and the appearance was significantly deteriorated.

Comparative Example 3 Number of detected pinholes with a diameter of 0.1 mm or more, 5 /
The same laminated film as in Example 1 was obtained except that the thickness was 1,000 m ² , a metal plate was obtained, and a metal container was obtained. As a result, the number of rusted cans was 4 / 50,000, and the presence of pinholes was confirmed in the defective cans. As described above, the film had a low commercial value because rust was generated in the metal can material due to the presence of pinholes and the appearance was significantly deteriorated.

Reference Example 1 When carried out on a laminated metal plate sample having no pinholes, no rust was found after one month, and there was no significant deterioration in the appearance due to rust, which was of high commercial value. there were. Reference Example 2 When the test was carried out on a sample having a pinhole with a diameter of 0.05 mmφ, no rust was found after one month, and there was no significant deterioration of the appearance due to rust, which was of high commercial value. It was Reference Example 3 When carried out on a sample having a pinhole with a diameter of 0.1 mmφ, rust was observed after 1 month,
It was confirmed that the appearance was remarkably deteriorated due to rust, and the product value was low. Reference Example 4 When carried out on a sample in which a pinhole having a diameter of 0.2 mmφ is present, the occurrence of rust is recognized after one month,
It was confirmed that the appearance was remarkably deteriorated due to rust, and the product value was low.

Example 2 The same laminated film as in Example 1 was obtained except that the curing temperature was 170 ° C. The abrasion resistance index of the obtained laminated film was 0.30%, and the static friction coefficient was 0.10. The number of detected pinholes having a diameter of 0.1 mmφ or more was 0 / 20,000 m ² . Using the laminated film,
The laminated steel sheet and the metal container obtained by the same method as in Example 1 have excellent wear resistance on the surface of the cured heat-resistant layer of the laminating film, and the number of rusted cans is 0 / 1,00.
It was 10,000 cans and was as highly practical as in Example 1.

Example 3 70 parts of a bisphenol A type epoxy resin, 30 parts of hexamethoxymethylolated melamine were added to a cured heat resistant resin composition.
The composition was changed to 0.10 part of p-toluenesulfonic acid, 0.1 part of higher fatty acid wax, 0.4 part of fluororesin, and 1.2 parts of silicone resin, and the drying temperature was changed to 8
The same laminated film as in Example 1 was obtained except that 0 ° C. and the curing temperature were 165 ° C. The residual solvent after leaving the drying step was 155 ppm. The abrasion resistance index of the obtained laminated film was 0.22%, and the static friction coefficient was 0.09. The number of detected pinholes having a diameter of 0.1 mmφ or more was 0 / 20,000 m ² . A laminated steel sheet obtained by the same method as in Example 1 using the laminated film,
The metal container has excellent wear resistance on the surface of the cured heat-resistant layer of the laminating film, and the number of rusted cans is 0 / 1,000,000 cans. It was expensive.

Comparative Example 4 The same laminated film as in Example 3 was obtained except that the drying temperature was 80 ° C. and the curing temperature was 135 ° C. (hot air heating). The abrasion resistance index of the obtained laminated film was 1.7%. The coefficient of static friction was 0.09, and the number of pinholes with a diameter of 0.1 mm or more was 0 / 20,000 m ² . The laminated film obtained in this Comparative Example had good slipperiness and a small number of pinholes, but poor abrasion resistance. The laminated steel sheet and the metal container obtained by using the laminated film in the same manner as in Example 1 were inferior in abrasion resistance on the surface of the cured heat-resistant layer of the laminating film.
It was inferior in practicality as well.

[0032]

INDUSTRIAL APPLICABILITY The film for laminating on the metal plate, the laminated metal plate and the metal container of the present invention are excellent in abrasion resistance of the surface of the cured heat-resistant layer of the film for lamination and corrosion resistance of the metal can material, Glossy and excellent in scratch resistance,
In addition, it is possible to provide a cosmetic metal plate and a cosmetic metal container that do not deteriorate in appearance due to the occurrence of rust, and can be suitably used as a metal can material such as soft drinks, beer, and canned foods.

[Brief description of drawings]

FIG. 1 shows a device and a method for detecting a pinhole in a film.

[Explanation of symbols]

 1: Unwinding shaft and film before pinhole detection test 2: Guide roller 3: Detection part roller 4: Detection electrode 5: Guide roller 6: Pressure contact roller 7: Film after winding shaft and pinhole detection test 8: High Voltage generator and pinhole detection data processor 9: Cable connection

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsutomu Isaka 2-2-2, Dojimahama, Kita-ku, Osaka Toyobo Co., Ltd.

Claims (7)

[Claims] 1. A laminated film having a substantially transparent cured heat-resistant layer provided on at least one side of a thermoplastic resin film, wherein the abrasion resistance index of the surface of the cured heat-resistant layer evaluated by the method defined in the text is 1. 2% or less and a diameter of 0.
A film for laminating on a metal plate, wherein the number of pinholes of 1 mmφ or more is 0 / 1,000 m ² or less. 2. The number of pinholes according to claim 1 is 0 /
A film for laminating on a metal plate, which is 10,000 m ² or less. 3. The number of pinholes according to claim 1 is 0 /
A film for laminating on a metal plate, which is 100,000 m ² or less. 4. A method of detecting a pinhole according to claim 1, wherein the pinhole is detected by a high voltage applying type pinhole detector. 5. A film for laminating on a metal plate, wherein the thermoplastic resin film according to claim 1 is a polyester film. 6. A laminated metal plate, which is obtained by laminating the film according to any one of claims 1 to 5 on a metal plate with the cured heat-resistant layer facing away from the metal plate. 7. A metal container formed by using the laminated metal plate according to claim 6 and having a laminate layer on the outside.