JP2006035509A - Resin-coated aluminium alloy sheet and can lid using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin-coated aluminum alloy sheet adapted to a can lid having stable opening properties and feathering resistance, and the can lid using it. <P>SOLUTION: The resin-coated aluminum alloy sheet is obtained by laminating at least on one side of an aluminum alloy sheet having a large number of micropores having a specific shape formed to its surface with a multilayered resin containing a polyolefin resin and subjected to molding processing to obtain the can lid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin-coated aluminum alloy plate, and more particularly to a resin-coated aluminum alloy plate used for a can lid (easy open end or EOE) that can be easily opened by hand, and a can lid using the same.

  For beverage cans filled with juice and beer in recent years and food cans filled with vegetables and fish meat etc., a can lid called Easy Open End or EOE that can be easily opened by hand without using an opening jig such as a can opener (Hereinafter referred to as EOE) is attached. These EOEs used were a metal plate such as an aluminum alloy coated with a paint. However, from the viewpoint of adverse effects on the environment caused by the scattering of organic solvents and fume when applying paint to a metal plate and baking it, a resin-coated metal plate coated with a thermoplastic resin instead of applying paint is designated as EOE. It has come to be used.

  Examples of applying a resin-coated aluminum alloy plate to a can material include the following. For example, Patent Document 1 discloses that a polyester resin or a polyester resin and a polycarbonate resin are formed on an aluminum alloy plate in which a large number of fine holes having an average diameter of 50 to 3000 nm and a maximum depth of 1000 nm or less are formed and the occupied area ratio is 10 to 90%. A thermoplastic resin-coated aluminum alloy plate is proposed.

  The thermoplastic resin-coated aluminum alloy sheet described in this publication is subjected to severe processing such as drawn iron cans, cans that have been stretched after drawing, stretched after drawing, and cans that have been further ironed. In particular, it is intended to be applied to applications that require processing adhesion of the film, and is not intended to be applied to a can lid. Therefore, the opening property when applied to the can lid, that is, the property that can be opened without tearing the V-shaped score processed part and opening the resin without leaving the resin on the opening end face (feathering) is not necessarily good. A stable aperture cannot be obtained.

Prior art document information relating to the present application includes the following.
Japanese Patent Laid-Open No. 09-226052

  An object of the present invention is to provide a resin-coated aluminum alloy plate applied to a can lid having stable opening properties and feathering resistance, and a can lid using the same.

In order to achieve the object of the present invention, the resin-coated aluminum alloy plate of the present invention has fine holes having an average diameter of 50 to 3000 nm and a maximum depth of 1000 nm or less, and the occupied area ratio of the fine holes is 10 to 90. % Is a resin-coated aluminum alloy plate (Claim 1) obtained by coating a multilayer resin containing a polyolefin resin on at least one surface of an aluminum alloy plate that is%.
In the resin-coated aluminum alloy plate of the above (Claim 1), the fine holes are formed with an average diameter of 200 to 900 nm and a depth shallower than ½ of the diameter (Claim 2). Moreover, in the resin-coated aluminum alloy plate of the above (Claim 1 or 2), the multilayer resin containing the polyolefin resin is a two-layer resin comprising an upper layer of an alicyclic polyolefin resin and a lower layer of a modified polyolefin resin. (Claim 3), or the multilayer resin containing the polyolefin resin is a two-layer resin composed of an upper layer made of a blend resin of an alicyclic polyolefin resin and a chain polyolefin resin and a lower layer of a modified polyolefin resin (claim) Item 4), or the multilayer resin layer containing the polyolefin resin comprises an upper layer of an alicyclic polyolefin resin and an alicyclic poly It is a three-layer resin comprising an intermediate layer composed of a blend resin of a olefin resin and a chain polyolefin resin and a lower layer of a modified polyolefin resin (Claim 5), or a multilayer resin containing the polyolefin resin is a polyester resin and a polyolefin. It is a two-layer resin composed of an upper layer composed of a resin blend resin and a lower layer of a copolyester resin (Claim 6), or a multilayer resin containing the polyolefin resin comprises an upper layer of a polyester resin, a polyester resin and a polyolefin It is a two-layer resin comprising a lower layer made of a resin blend resin (Claim 7), or the multilayer resin containing the polyolefin resin is an upper layer of a polyester resin and an intermediate layer made of a blend resin of a polyester resin and a polyolefin resin And under the copolyester resin Characterized in that it is a three-layer resin (claim 8) consisting of a.

  The can lid of the present invention is a can lid (invention 9) using the resin film-coated aluminum alloy plate of the above (inventions 1 to 8).

  The resin-coated aluminum alloy plate of the present invention is obtained by coating a multi-layer resin containing a polyolefin resin on an aluminum alloy plate having a number of fine holes of a specific shape formed on the surface. When used for easy open end or EOE), it is easy to open and is less likely to cause feathering. Therefore, it can be suitably applied as a material for EOE.

  In the present invention, by using a resin-coated aluminum alloy plate formed by coating a multilayer resin containing a polyolefin resin on an aluminum alloy plate having a number of micro holes with a specific shape formed on the surface, an opening is obtained. And feathering resistance can be obtained in good condition at all times. The contents of the present invention will be described below.

  Conventionally, attempts have been made to use a polyester resin-coated metal plate obtained by laminating and coating a polyester resin on an aluminum alloy or tin-free steel as a material for EOE. The polyester resin is stretched in the vertical and horizontal biaxial directions, and then formed into a film in which the oriented crystal state is heat-fixed, thereby exhibiting excellent properties such as strength, workability, and permeation resistance such as liquid and gas. When a polyester-coated metal plate obtained by laminating and coating a biaxially stretched polyester film on a metal plate is used as a can material, the biaxially stretched polyester film is brought into contact with the metal plate heated above the heat setting temperature of the biaxially stretched polyester film and heated. Crimp. In order to improve adhesive strength, an adhesive may be interposed between the polyester film and the metal plate. When thermocompression bonding, the resin in the portion in contact with the metal plate loses its oriented crystalline state and becomes amorphous, the tensile strength is reduced, the elongation is improved, and the workability is increased. This amorphous portion increases as the heating temperature of the metal plate is high and the time in contact with the metal plate is longer. For this reason, when a polyester-coated metal plate is applied to cans that are subjected to severe processing such as a drawn can and a squeezed iron can, workability is improved by increasing the amorphized portion.

  On the other hand, when the polyester-coated metal plate is applied to EOE, when the V-shaped score processed portion provided on the metal plate is torn and opened, the metal plate and the coated polyester film are torn together, and the opening end face is formed. It is required to have both openability (film tearability) and adhesiveness (feathering resistance) so that the resin film does not remain or the polyester film does not peel (feathering) from parts other than the pull tab of the can lid. The In order to satisfy such characteristics, the thickness of the polyester film, the physical properties such as tensile strength and elongation before lamination on the metal plate, that is, the plane orientation coefficient of the film, that is, the draw ratio, the heat setting temperature, etc. Films with strictly controlled membrane conditions are used, and the temperature of the metal plate is kept within a certain range when laminating to the metal plate, and the contact temperature and pressure with the metal plate are strictly controlled. Must be managed. However, since the range that satisfies the above characteristics is extremely narrow, it is extremely difficult to produce a polyester-coated metal plate applicable to EOE at a high yield even if the film forming conditions are strictly controlled.

  In the present invention, in order to improve the opening property, that is, the tearability of the resin film, a multilayer resin containing a polyolefin resin is laminated and coated on an aluminum alloy plate having a number of fine holes of a specific shape formed on the surface. It is applied as an EOE material that has excellent tearability and is less likely to cause feathering.

  The multilayer resin containing the polyolefin resin laminated and coated on the resin-coated aluminum alloy plate of the present invention includes a multilayer resin obtained by laminating various polyolefin resins in two or three layers, or a polyester resin and an incompatible polyolefin resin. A multilayer resin obtained by laminating a resin blended with other polyester resin in two or three layers is used. As the former multilayer resin, an alicyclic polyolefin resin having poor adhesion to a metal plate is used as an upper layer, and adhesion to a metal plate formed by graft polymerization of an unsaturated carboxylic acid or its anhydride to a chain polyolefin resin is achieved. A two-layer resin having an excellent modified polyolefin resin as a lower layer film, or a blend resin obtained by blending an expensive alicyclic polyolefin resin with an inexpensive chain polyolefin resin as an upper layer, and the above modified polyolefin resin as a lower layer film Reduce the amount of expensive alicyclic polyolefin resin by using alicyclic polyolefin resin as the upper layer, blend resin consisting of the above alicyclic polyolefin resin and chain polyolefin resin as the intermediate layer, and the above modified polyolefin resin as the lower layer It is preferable to use any one of the three-layer resins.

  In these former multilayer resins, norbornene and its alkyl and / or alkylidene substituted products are used alone as the upper resin layer or as the alicyclic polyolefin resin used together with the chain polyolefin resin as the blend resin of the upper layer or the intermediate layer. , Dicyclopentadiene, 2,3-dihydrodicyclopentadiene and their alkyl and / or alkylidene-substituted products, or 3 to 4 mers of cyclopentadiene are polymerized by ring-opening polymerization method. A polymer obtained by hydrogenating the obtained ring-opening polymer can be used. These alicyclic polyolefin resins preferably have a glass transition temperature of 100 ° C. or higher. When an alicyclic polyolefin resin having a glass transition temperature of less than 100 ° C. is used, the film tends to stretch when formed into a film together with other resin layers. Feathering tends to occur, which is not preferable.

  As the modified polyolefin resin used as the lower layer, low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene, ethylene including ethylene / propylene copolymer, Either a random copolymer of α-olefins such as propylene, 1-butene, 4-methyl-1-pentene or a chain polyolefin resin such as a block copolymer, acrylic acid, methacrylic acid, maleic acid, fumar So-called acid-modified polyolefins obtained by graft polymerization of unsaturated carboxylic acids such as acids and itaconic acids and their anhydrides in an amount of 2% or less can be used.

  As the chain polyolefin resin used together with the alicyclic polyolefin resin as the blend resin of the upper layer or the intermediate layer, low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene, Or any of chain polyolefin resins such as random copolymers or block copolymers of α-olefins such as ethylene / propylene, ethylene, propylene, 1-butene, 4-methyl-1-pentene, etc. It is preferable to use these.

  Blend resin of alicyclic polyolefin resin and chain polyolefin resin is a blend resin formed by blending 10 to 90% by weight of alicyclic polyolefin resin and 90 to 10% by weight of chain polyolefin resin in the blend resin. Preferably there is. In this blend resin, if the alicyclic polyolefin resin is less than 10% by weight, good openability cannot be obtained, and if it exceeds 90% by weight, the effect of reducing the film cost of blending the chain polyolefin resin becomes poor. Further, in place of these chain-type polyolefin resins, either an ionomer resin or the above-mentioned acid-modified polyolefin resin may be blended with an alicyclic polyolefin resin.

  The above alicyclic polyolefin resin, blend resin, and modified polyolefin resin pellets are heated and melted using a co-extruder capable of extruding multiple layers of resin film, and extruded from a T-die to form a two-layer resin film or a three-layer resin film. To form a film. The two-layered resin film of the present invention thus obtained has a total thickness of 10 in the case of any of the three-layer resin film of the upper layer and the lower layer, and the upper layer, the intermediate layer, and the lower layer three-layer film. It is preferably ˜50 μm. When the total thickness is less than 10 μm, when the aluminum alloy plate is laminated and coated and used as a can lid, the content may penetrate the resin film and corrode the coated aluminum alloy plate. On the other hand, if it exceeds 50 μm, a large force is required for the opening, and feathering is likely to occur, which is not preferable. In the two-layer resin film or the three-layer resin film having a total thickness of 10 to 50 μm, the thickness of the modified polyolefin resin in the lower layer is preferably 10 to 60% of the total thickness. When the thickness of the modified polyolefin resin is less than 10%, the adhesive force between the resin film and the aluminum alloy plate is insufficient, and the resin film is easily peeled off at the portion outside the pull tab surrounded by the score groove when opening. On the other hand, even if it exceeds 60%, the effect of improving the adhesive strength is saturated, and the cost is not advantageous.

  Moreover, it is preferable that the breaking elongation of the two-layer or three-layer resin film made of the above-mentioned various polyolefin resins is 200% or less. When an EOE using a resin film having an elongation at break exceeding 200% is opened in this temperature range, the resin film is difficult to tear and feathering is likely to occur. The elongation at break is particularly preferably 200% or less in the temperature range of 0 to 100 ° C. Cans filled with cold drinks such as juices and carbonated drinks are brought to a temperature below 0 ° C before leaving for excursions, etc., and opened with the contents frozen at the destination There is. In addition, a can filled with beverages such as soup flour and soup may be opened in a heated state by being immersed in boiling water. Thus, since the can lid may open in a temperature range of 0 to 100 ° C., in order to prevent the occurrence of feathering in this temperature range, the elongation at break of the resin film for can lid is 0 to 100. It is preferably 200% or less in the temperature range of ° C.

  On the other hand, as a multilayer resin in which the latter polyester resin and a resin blended with an incompatible polyolefin resin and another polyester resin are laminated in two or three layers, the upper layer is a blend resin composed of a polyester resin and a polyolefin resin, The lower layer is a polyester resin two-layer resin, or the upper layer is a polyester resin, the lower layer is a blend resin composed of a polyester resin and a polyolefin resin, or the upper layer is a polyester resin, and the intermediate layer is a blend resin composed of a polyester resin and a polyolefin resin, It is preferable that the lower layer has any structure of a three-layer resin of polyester resin. The blend resin comprising a polyester resin and a polyolefin resin used for these two-layer or three-layer resins is preferably one obtained by blending 30 to 5% by weight of a polyolefin resin with 70 to 95% by weight of a polyester resin. If the blend amount of the polyolefin resin is less than 5% by weight, sufficient tearability cannot be obtained. On the other hand, blending in excess of 30% by weight is not preferable because the tensile strength of the resin film is significantly reduced.

  Polyester resins used as blend resins of two-layer resins and three-layer resins include homopolymers such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and some of the polybasic acids and polyhydric alcohols that make up these homopolymers Copolyester resin obtained by substituting with a polybasic acid or polyhydric alcohol can be used, but polyethylene terephthalate is preferably used from the viewpoint of low cost and ease of film formation. As the polyolefin resin, it is preferable to use any of polyethylene, polypropylene, and ethylene / propylene copolymer that are inexpensive and widely used.

  As the polyester resin used as the upper layer of the three-layer resin, a polyester resin similar to the polyester resin used for the blend resin can be applied, but polyethylene is used from the viewpoint of excellent flavor properties, low cost, and ease of film formation. It is preferable to use terephthalate.

  The polyester resin used as the upper or lower layer of the two-layer resin and as the lower layer in the three-layer resin includes homopolymers such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and polybasic acids constituting these homopolymers. Copolymerized polyester resin obtained by substituting a part of polyhydric alcohol with other polybasic acid or polyhydric alcohol can be applied, but it is relatively inexpensive, widely used, and has excellent flavor properties ethylene terephthalate / ethylene isophthalate It is preferable to use a copolymer. This copolyester resin is preferably composed of 75 to 90 mol% ethylene terephthalate and 25 to 10 mol% ethylene isophthalate from the viewpoint of adhesiveness.

In order to improve tearability, these polyester resins may contain inorganic particles. The inorganic particles are preferably silicon oxide or titanium oxide having an average particle size of 0.2 to 5.0 μm. If the average particle size is less than 0.2 μm, the tearability is not improved unless the resin is contained in a large amount in the resin, and if it is contained in the resin in a large amount, the adhesiveness of the resin to the aluminum alloy plate is deteriorated. When the average particle diameter exceeds 5.0 μm, the rivet workability and the workability for forming the convex portions are lowered, which is not preferable. From the viewpoint of tearability, these inorganic particles are preferably contained in a large amount in the case of fine particles and in a small amount in the case of coarse particles. Therefore, it is preferable to contain inorganic particles in the polyester resin so as to satisfy the following formula, which is a product obtained by multiplying the average particle diameter and the content.
3 ≦ content (% by weight) × average particle size (μm) ≦ 10
When the value of content (% by weight) × average particle diameter (μm) is less than 3 or exceeds 10, good tearability cannot be obtained.

  The polyester resin containing the inorganic particles thus obtained preferably has a breaking elongation of 250% or less in the state of a single-layer resin film. If the elongation at break exceeds 250%, it becomes difficult to break, and good tearability cannot be obtained.

  A plurality of the above-mentioned polyester resin and polyolefin resin blend resin and polyester resin pellets selectively containing inorganic particles, or the above polyester resin, blend resin, and polyester resin pellets selectively containing inorganic particles, The resin film of the layer is heated and melted using a co-extruder capable of extruding and extruded from a T-die to form a two-layer resin film or a three-layer resin film. The total thickness of the two-layer resin film thus obtained is 10 to 50 μm, the thickness of the blend resin is 7 to 40 μm, and the thickness of the polyester resin containing inorganic particles selectively is 3 to 10 μm. Preferably there is. When the total thickness is less than 10 μm, when the aluminum alloy plate is laminated and coated to form a can lid, the content may permeate the resin film and corrode the aluminum alloy plate of the coating base. On the other hand, if it exceeds 50 μm, a large force is required for the opening, and feathering is likely to occur, which is not preferable. In addition, in this two-layer resin film having a total thickness of 10 to 50 μm, a good tearing is obtained when the thickness of the upper resin is less than 7 μm and the thickness of the polyester resin containing the inorganic particles selectively in the lower layer is less than 3 μm. Sex cannot be obtained. Further, when a copolyester resin is used as the polyester resin, it is expensive, so the upper limit is 10 μm.

  The thickness of the three-layer resin film is 10 to 50 μm for the same reason as in the case of the two-layer resin film, and the thickness of the upper polyester resin provided for improving the flavor property is 1 to 10 μm. Preferably it is. As a result, for the same reason as in the case of the two-layer resin film, the thickness of the blend resin is preferably 6 to 30 μm, and the thickness of the polyester resin that selectively contains inorganic particles is preferably 3 to 10 μm.

  As a substrate for coating a multilayer resin containing the above polyolefin resin, it is necessary to have excellent adhesion, and the surface has a large number of micropores having an average diameter of 50 to 3000 nm and a maximum depth of 1000 nm or less, preferably It has a large number of fine holes formed with an average diameter of 300 to 1500 nm and a depth shallower than ½ of the diameter, and the occupied area ratio of the fine holes is 10 to 90%, preferably 30 to 70%. When an aluminum alloy plate is used, a multilayer resin or polyester resin obtained by laminating the above-described various polyolefin resins in two or three layers and a resin blended with an incompatible polyolefin resin and two other polyester resins or Excellent adhesion is obtained when a multilayer resin laminated in three layers is coated, and feathering is less likely to occur when applied to EOE. Such micropores can be formed by treatment with an aqueous alkali solution followed by treatment with an aqueous acid solution. Further, the surface shape formed by this treatment can be specified by measurement using an atomic force microscope or the like.

  The resin-coated aluminum alloy plate of the present invention is obtained by laminating and coating a multilayer resin containing the above polyolefin resin on at least one surface of a substrate made of the above aluminum alloy plate. When the multilayer resin is a multilayer resin in which various polyolefin resins are laminated in two or three layers, the modified polyolefin resin, which is the lower layer of the two or three layers, is in contact with the substrate made of an aluminum alloy plate. When the multilayer resin is a multilayer resin obtained by laminating a polyester resin and a resin that is incompatible with the polyester resin and another polyester resin in two or three layers, the polyester resin is a lower layer of two or three layers. Alternatively, the polyester resin and the polyolefin resin, which are the lower layers of the two layers, are bonded using a known thermal bonding method so that the blended resin is in contact with the substrate made of an aluminum alloy plate. In order to increase the adhesive strength, heat bonding may be performed between the aluminum alloy plate and the multilayer resin via an adhesive. Further, in the production of the multilayer resin described above, when each resin pellet is heated and melted by a co-extruder and co-extruded from a T die, it may be directly extruded onto an aluminum alloy plate to be laminated.

  In the case of the can lid of the present invention, the resin-coated aluminum alloy plate obtained as described above is punched into a disc-shaped blank, and in the case of an aluminum alloy plate in which the resin is coated on one side or only one side of the aluminum alloy plate It is obtained by engraving score grooves on the surface not coated with the resin film. Hereinafter, the present invention will be described in more detail with reference to examples.

(Creation of multilayer resin)
Multi-layer resins composed of various polyolefin resins include norbornene (indicated by NRa in Table 1) having a glass transition temperature of 100 ° C. as an alicyclic polyolefin resin, and norbornene (in Table 1 having a glass transition temperature of 135 ° C.). NRb), polyethylene as a chain polyolefin resin (indicated by PE in Table 1), and a modified polyethylene resin (MPE in Table 1) obtained by graft polymerization of maleic anhydride as an acid-modified polyolefin resin by 0.5% by weight. Table 1 shows an extrusion method using a modified polyethylene resin (indicated as APE in Table 1) and an ionomer (indicated as IOM in Table 1) formed by graft polymerization of 0.7% by weight of acrylic acid. A two-layer or three-layer unstretched resin film (resin numbers: a to i) having a resin composition, a layer configuration, and a thickness was prepared. For comparison, polyester resin film (ethylene terephthalate (95 mol%) / ethylene isophthalate (5 mol%) copolymer having an upper layer thickness of 15 μm is indicated as ET (95) / EI (5) in Table 1). ), A two-layer film of an ethylene terephthalate (85 mol%) / ethylene isophthalate (15 mol%) copolymer (indicated as ET (85) / EI (15) in Table 1) having a lower layer thickness of 5 μm) A biaxially stretched film (resin number: j, plane orientation coefficient: 0.145) was also prepared. The plane orientation coefficient of the polyester resin film was calculated from the refractive index in the plane direction (longitudinal direction, lateral direction) and thickness direction measured using an Abbey refractometer. The elongation of these formed resin films was measured with Tennsilon.

  A multilayer resin in which a polyester resin and a resin blended with an incompatible polyolefin resin and another polyester resin are laminated in two or three layers are polyethylene terephthalate (shown as PET in Tables 2 and 3), polyethylene (table 2 and 3 as PE), polypropylene (as PP in Tables 2 and 3), ethylene / propylene copolymer consisting of 60 mol% ethylene and 40 mol% propylene (E in Tables 2 and 3) (Indicated by P)), an ethylene terephthalate / ethylene isophthalate copolymer (indicated in ET / EI in Tables 2 and 3) composed of 85 mol% ethylene terephthalate containing silicon oxide and 15 mol% ethylene isophthalate, Or 85 mol% ethylene terephthalate and 15 mol% ethylene isophthalate containing titanium oxide Resin compositions and layers shown in Table 2 and Table 3 by extrusion method using pellets of tylene terephthalate / ethylene isophthalate copolymer (shown as ET (85) / EI (15) in Tables 2 and 3). A two-layer or three-layer unstretched resin film (resin numbers: k to y) having a configuration and thickness was prepared. For comparison, an ethylene terephthalate / ethylene isophthalate copolymer composed of 85 mol% ethylene terephthalate and 15 mol% ethylene isophthalate containing silicon oxide or titanium oxide used as an upper layer or lower layer of these resin films (Table A single layer film (resin number: z) of ET (85) · EI (15) in No. 3 was also prepared by an extrusion method. The elongation of these formed resin films was measured with Tennsilon.

(Aluminum alloy plate processing)
As a substrate for coating the multilayer resin formed as described above, an aluminum alloy plate (JIS: 5182, thickness: 0.30 mm) was treated with an alkaline aqueous solution under the following conditions, and subsequently treated with an acid aqueous solution. .
[Treatment with alkaline aqueous solution]
After immersing in a 50 g / L sodium hydroxide aqueous solution heated to 50 ° C. for 3 to 15 seconds, washed with water and dried.
[Treatment with aqueous acid solution]
After being immersed in an aqueous sulfuric acid solution having a concentration of 70 g / L at room temperature for 3 to 10 seconds, it was washed with water and dried.

In this way, multilayer resin-coated substrates having substrate numbers A, B, and C having the average diameter (nm), maximum depth (nm), and micropore occupation area ratio (%) of the micropores shown in the following table were obtained. .

(Preparation of resin-coated aluminum alloy plate)
Next, the multilayer resin films shown in Tables 1 to 3 were laminated and coated on one side of these multilayer resin-coated substrates using a thermal bonding method, and resin-coated aluminum alloy plates shown in Tables 1 to 3 (sample numbers: 1 to 26). )created. The aluminum alloy plate on which the polyester resin film for comparison was laminated and coated was prepared by changing the thermal bonding conditions to slightly lower the orientation (sample number: 10).

A disk-shaped blank is punched out of the resin-coated aluminum alloy plates of sample numbers 1 to 26 shown in Tables 1 to 3 shown in Tables 1 to 3 so that the score remaining thickness is 50 μm on the surface not coated with the resin film. Thus, a score groove was cut and a pull tab ring was attached to create an EOE can lid. 500 EOE can lids were made from each sample plate and opened, and the residual state of the resin at the opening end was visually observed, and the feathering resistance was evaluated according to the following criteria.
A: Residual resin is not observed in all 500 pieces.
○: Residual resin remains slightly in less than 2 out of 500 pieces.
Δ: Resin remains in 2 to 5 but less than 500 pieces.
X: Residual resin is observed in 5 or more of 500 pieces.
The evaluation results are shown in Table 4.

  As shown in Table 4, the can lid prepared from the resin-coated aluminum alloy plate of the present invention exhibits excellent feathering resistance.

  When the resin-coated aluminum alloy plate of the present invention is used as an EOE for a can lid, it is possible to stably open without causing feathering.

Claims (9)

  A multilayer resin containing a polyolefin resin is coated on at least one surface of an aluminum alloy plate having fine holes having an average diameter of 50 to 3000 nm and a maximum depth of 1000 nm or less, and the occupied area ratio of the fine holes is 10 to 90%. A resin-coated aluminum alloy plate.   2. The resin-coated aluminum alloy plate according to claim 1, wherein the fine holes are formed with an average diameter of 200 to 900 nm and a depth shallower than ½ of the diameter.   The resin-coated aluminum alloy plate according to claim 1 or 2, wherein the multilayer resin containing the polyolefin resin is a two-layer resin comprising an upper layer of an alicyclic polyolefin resin and a lower layer of a modified polyolefin resin.   The resin according to claim 1 or 2, wherein the multilayer resin containing the polyolefin resin is a two-layer resin composed of an upper layer composed of a blend resin of an alicyclic polyolefin resin and a chain polyolefin resin and a lower layer of a modified polyolefin resin. Coated aluminum alloy plate.   The multilayer resin containing the polyolefin resin is a three-layer resin comprising an upper layer of an alicyclic polyolefin resin, an intermediate layer made of a blend resin of an alicyclic polyolefin resin and a chain polyolefin resin, and a lower layer of a modified polyolefin resin. The resin-coated aluminum alloy plate according to claim 1 or 2.   The resin-coated aluminum alloy plate according to claim 1 or 2, wherein the multilayer resin containing the polyolefin resin is a two-layer resin composed of an upper layer composed of a blend resin of a polyester resin and a polyolefin resin and a lower layer of a copolyester resin. .   The resin-coated aluminum alloy plate according to claim 1 or 2, wherein the multilayer resin containing the polyolefin resin is a two-layer resin including an upper layer of a polyester resin and a lower layer made of a blend resin of the polyester resin and the polyolefin resin.   The multilayer resin containing the polyolefin resin is a three-layer resin composed of an upper layer of a polyester resin, an intermediate layer composed of a blend resin of the polyester resin and the polyolefin resin, and a lower layer of a copolyester resin. The resin-coated aluminum alloy plate described.   A can lid using the resin-coated aluminum alloy plate according to claim 1.