JP6464611B2 - Packaging material and manufacturing method thereof - Google Patents

Description

  The present invention relates to a packaging material in which deterioration due to acidic or alkaline contents is suppressed.

Conventionally, as a packaging material that contains acidic or alkaline contents such as chemicals, cosmetics, foods, and electrolytes, a metal layer and a sealant layer (heat sealing resin layer) that have been subjected to chemical conversion treatment have been laminated on the surface. There are known (see, for example, Patent Document 1).
As a chemical conversion treatment of the metal layer, for example, a method of forming a corrosion-resistant film by performing a chromate treatment on the surface of the metal layer is known. The presence of such a corrosion-resistant film between the metal layer and the sealant layer causes the acidic or alkaline contents contained in the packaging material to permeate from the sealant layer side to the metal layer side. Deterioration of the packaging material such as corrosion of the metal and peeling of the metal layer and the sealant layer is suppressed.

JP 2008-287971 A

As described above, in the packaging material in which the corrosion-resistant film is formed between the metal layer and the sealant layer, deterioration of the packaging material due to acidic or alkaline contents is suppressed.
However, as a result of the study by the present inventors, in a packaging material in which a corrosion-resistant film is provided on the surface of the metal layer, when the acidic or alkaline content is contained in the packaging material, the packaging material is made of the acidic or alkaline content. It has been found that there is a case where deterioration of the material occurs. Specifically, when acid or alkaline contents are contained in the packaging material, the adhesive strength between the corrosion-resistant film and the sealant layer on the surface of the metal layer is reduced, and the corrosion-resistant film and the sealant layer are easily peeled off. It was found that there is.
Under such circumstances, a main object of the present invention is to provide a packaging material in which deterioration due to acidic or alkaline contents is suppressed, and a method for producing the packaging material.

The inventors of the present invention have made extensive studies to solve the above problems, and have obtained the following knowledge. Conventionally, the chemical conversion treatment on the surface of the metal layer as described above is performed by a method of uniformly applying a treatment liquid for forming a corrosion-resistant film on the surface of the metal layer using a roll. However, the present inventors measured the amount of metal element contained in the corrosion-resistant film with a fluorescent X-ray analyzer (XRF) at a plurality of locations in the width direction of the packaging material (the axial direction of the roll to which the treatment liquid is applied). As a result, it has been clarified that the amount of the metal element contained in the corrosion-resistant film is uneven, and deterioration due to acidic or alkaline contents is likely to occur at a location where the amount of the metal element is small.
Based on such knowledge, the present inventors further examined that, as a roll for applying a corrosion-resistant film, the outer diameter is a shaft instead of a generally used cylindrical roll having the same outer diameter in the axial direction. When a roll having a crown shape that is maximum at the center of the direction and minimum at both ends is used, the uniformity of the amount of the metal element contained in the corrosion-resistant film is increased in the width direction of the packaging material, and it is acidic or alkaline. The present inventors have found that a packaging material in which deterioration due to the contents of is suppressed can be obtained. The present invention has been completed by further studies based on these findings.

That is, this invention provides the invention of the aspect hung up below.
Item 1. At least a metal layer, a corrosion-resistant film formed on the surface of the metal layer, and a laminate in which a sealant layer is sequentially laminated,
A is the difference between the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate, and the average of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate A packaging material in which the value calculated by the following formula 1 is 20% or less when the value is B.
Formula 1: A / B × 100
Item 2. Average value B of the content of the metal element contained in the corrosion-resistant coating in the width direction of the laminate is in the range of 2.0~5.0mg / m ^2, the packaging material according to claim 1.
Item 3. Item 3. The packaging material according to Item 1 or 2, wherein a corrosion-resistant film is further formed on the surface of the metal layer opposite to the sealant layer.
Item 4. Item 4. The packaging material according to any one of Items 1 to 3, wherein the metal element is chromium, aluminum, titanium, cerium, tin, or barium.
Item 5. Item 5. The packaging material according to any one of Items 1 to 4, wherein the sealant layer has a thickness in the range of 10 to 100 μm.
Item 6. Item 6. The packaging material according to any one of Items 1 to 5, wherein a base material layer is laminated on the side of the metal layer opposite to the sealant layer.
Item 7. At least a method for producing a packaging material comprising a laminate in which a metal layer, a corrosion-resistant film formed on the surface of the metal layer, and a sealant layer are sequentially laminated,
Using a roll having a crown shape whose outer diameter is maximum at the center in the axial direction and minimum at both ends, the coating amount is uniform in at least one of the surfaces of the metal layer in the width direction of the laminate. Applying a treatment liquid for forming the corrosion-resistant film, and forming a corrosion-resistant film on the surface;
Laminating the sealant layer on the corrosion-resistant film;
A method for producing a packaging material.
Item 8. In the corrosion-resistant film forming step, after immersing the metal layer in a treatment liquid for forming the corrosion-resistant film, a roll having the crown shape is used, and the coating amount of the treatment liquid on at least one surface of the metal layer is Item 8. The method for producing a packaging material according to Item 7, wherein the corrosion-resistant film is formed on the surface by adjusting the laminate so as to be uniform in the width direction.
Item 9. In the corrosion-resistant film forming step, using a roll having the crown shape,
A is the difference between the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate, and the average of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate Item 9. The method for producing a packaging material according to Item 7 or 8, wherein when the value is B, the corrosion-resistant film is formed such that the value calculated by the following formula 1 is 20% or less.
Formula 1: A / B × 100
Item 10. In the corrosion-resistant film forming step, the treatment liquid is applied in the width direction of the laminate while passing the metal layer coated on both surfaces between the two rolls having the crown shape. The manufacturing method of the packaging material in any one of claim | item 7 -9 which adjusts so that it may become uniform and forms a corrosion-resistant film | membrane on both surfaces of the said metal layer.
Item 11. Item 11. The method for producing a packaging material according to any one of Items 7 to 10, wherein the metal element is chromium, aluminum, titanium, cerium, tin, or barium.

  According to the present invention, it is possible to provide a packaging material in which deterioration due to acidic or alkaline contents is suppressed. Furthermore, according to this invention, the manufacturing method of the said packaging material can also be provided.

It is a figure which shows an example of the cross-sectional structure of the packaging material of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material of this invention. It is a schematic diagram of the roll which has a crown shape used in the manufacturing method of this invention. It is a schematic diagram for demonstrating the corrosion-resistant film formation process in the manufacturing method of this invention. It is a schematic top view of the packaging material for demonstrating the calculation method of the difference of the maximum value of metal element content contained in a corrosion-resistant film, and a minimum value. It is a measurement result of chromium element content of the corrosion-resistant film (sealant layer side) in Test Example 1, Test Example 2, and Comparative Test Example 1. It is a measurement result of chromium element content of the corrosion-resistant film (base material layer side) in Test Example 1, Test Example 2, and Comparative Test Example 1.

The packaging material of the present invention comprises a laminate in which at least a metal layer, a corrosion-resistant coating formed on the surface of the metal layer, and a sealant layer are sequentially laminated, and is included in the corrosion-resistant coating in the width direction of the laminate. When the difference between the maximum value and the minimum value of the content of the metal element is A, and the average value of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate is B, the following calculation is performed. The value is 20% or less.
Formula 1: A / B × 100

The method for producing a packaging material of the present invention is a method for producing a packaging material comprising a laminate in which at least a metal layer, a corrosion-resistant film formed on the surface of the metal layer, and a sealant layer are sequentially laminated. Then, using a roll having a crown shape whose outer diameter is maximum at the center in the axial direction and minimum at both ends, the coating amount is uniform in the width direction of the laminate on at least one of the surfaces of the metal layer. And a process for forming a corrosion-resistant film on the surface, and a step of laminating a sealant layer on the corrosion-resistant film.
Hereinafter, the packaging material of the present invention and the method for producing the packaging material will be described in detail.

1. Laminated structure of packaging material The packaging material of the present invention comprises at least a laminated body in which a metal layer 3, a corrosion-resistant film 4 a formed on the surface of the metal layer 3, and a sealant layer 5 are sequentially laminated. In the packaging material of the present invention, the sealant layer 5 is the innermost layer. That is, when the contents are accommodated by the packaging material of the present invention, the sealant layers 5 positioned at the periphery of the packaging material are thermally fused together to form a bag and the contents can be accommodated.

  In the packaging material of the present invention, as shown in FIG. 1, a corrosion-resistant film 4 b may be further formed on the surface of the metal layer 3 opposite to the sealant layer 5. Moreover, as shown in FIG. 1, the base material layer 1 may be laminated | stacked on the opposite side to the sealant layer 5 of the metal layer 3. As shown in FIG. When the packaging material of this invention has the base material layer 1, as shown in FIG. 2, between the base material layer 1 and the metal layer 3 (or between the base material layer 1 and the corrosion-resistant film | membrane 4b), these are shown. An adhesive layer 2 may be provided as necessary for the purpose of enhancing the adhesiveness. In addition, as shown in FIG. 3, an adhesive layer 6 may be provided between the corrosion-resistant film 4a and the sealant layer 5 as necessary for the purpose of enhancing these adhesive properties.

2. Composition of each layer forming the packaging material [base material layer 1]
In the packaging material of the present invention, the base material layer 1 is a layer provided as necessary for the purpose of improving the shape retention of the packaging material. 1-3, the base material layer 1 is located in the outermost layer. The material for forming the base material layer 1 is not particularly limited as long as it has insulating properties. Examples of the material for forming the base material layer 1 include polyester, polyamide, epoxy resin, acrylic resin, fluorine resin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, and a mixture or copolymer thereof. Can be mentioned.

  Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, copolymerized polyester mainly composed of ethylene terephthalate, butylene terephthalate as a repeating unit. Examples thereof include a copolymer polyester mainly used. The copolymer polyester mainly composed of ethylene terephthalate is a copolymer polyester that polymerizes with ethylene isophthalate mainly composed of ethylene terephthalate (hereinafter, polyethylene (terephthalate / isophthalate)). Abbreviated), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) And polyethylene (terephthalate / decanedicarboxylate). In addition, as a copolymer polyester mainly composed of butylene terephthalate as a repeating unit, specifically, a copolymer polyester that polymerizes with butylene isophthalate having butylene terephthalate as a repeating unit (hereinafter referred to as polybutylene (terephthalate / isophthalate)). For example), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate and the like. These polyesters may be used individually by 1 type, and may be used in combination of 2 or more type. Polyester is excellent in resistance to acid or alkali, and has an advantage that whitening or the like hardly occurs due to adhesion of acid or alkali, and is suitably used as a material for forming the base material layer 1 that may be located in the outermost layer. The

  Specific examples of polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 6,6; terephthalic acid and / or Nylon 6I, Nylon 6T, Nylon 6IT, Nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) and the like, which include a structural unit derived from isophthalic acid, Aromatic polyamides such as silylene adipamide (MXD6); alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); and lactam components and isocyanate components such as 4,4′-diphenylmethane-diisocyanate. Polymerized polyamide, co-weight Polyester amide copolymer and polyether ester amide copolymer is a copolymer of polyamide and polyester and polyalkylene ether glycol; copolymers thereof, and the like. These polyamides may be used individually by 1 type, and may be used in combination of 2 or more type. The stretched polyamide film is excellent in stretchability, can prevent whitening due to resin cracking of the base material layer 1 during molding, and is suitably used as a material for forming the base material layer 1.

  The base material layer 1 may be formed of a uniaxially or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, a uniaxially or biaxially stretched resin film, in particular, a biaxially stretched resin film has improved heat resistance by orientation crystallization, and thus is suitably used as the base material layer 1. Moreover, the base material layer 1 may be formed by coating the above-mentioned material on the metal layer 3 or the corrosion-resistant film 4b.

  Among these, as a resin film which forms the base material layer 1, Preferably nylon and polyester, More preferably, biaxially stretched nylon, biaxially stretched polyester, Most preferably, biaxially stretched nylon is mentioned.

  The base material layer 1 can also be laminated with at least one of resin films and coatings of different materials for the purpose of improving pinhole resistance. Specific examples include a multilayer structure in which a polyester film and a nylon film are laminated, and a multilayer structure in which a biaxially stretched polyester and a biaxially stretched nylon are laminated. When making the base material layer 1 into a multilayer structure, each resin film may be adhere | attached through an adhesive agent, and may be laminated | stacked directly without an adhesive agent. In the case of bonding without using an adhesive, for example, a method of bonding in a hot melt state such as a co-extrusion method, a sand lamination method, or a thermal laminating method can be mentioned. Moreover, when making it adhere | attach through an adhesive agent, the adhesive agent to be used may be a two-component curable adhesive, or a one-component curable adhesive. Further, the bonding mechanism of the adhesive is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressure type, an electron beam curing type such as UV and EB, and the like. As an adhesive component, polyester resin, polyether resin, polyurethane resin, epoxy resin, phenol resin resin, polyamide resin, polyolefin resin, polyvinyl acetate resin, cellulose resin, (meth) acrylic resin Resins, polyimide resins, amino resins, rubbers, and silicon resins can be used.

  As thickness of the base material layer 1, about 10-50 micrometers, for example, Preferably about 15-30 micrometers is mentioned.

[Adhesive layer 2]
In the packaging material of the present invention, the adhesive layer 2 is provided as necessary in order to enhance the adhesion between the base material layer 1 and the metal layer 3 or the corrosion-resistant film 4b when the base material layer 1 is provided. Is a layer.

  The adhesive layer 2 is formed of an adhesive capable of adhering the base material layer 1 and the metal layer 3 or the corrosion-resistant film 4b. The adhesive used for forming the adhesive layer 2 may be a two-component curable adhesive or a one-component curable adhesive. Furthermore, the adhesive mechanism of the adhesive used for forming the adhesive layer 2 is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressure type, and the like.

  Specific examples of the resin component of the adhesive that can be used to form the adhesive layer 2 include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolyester. Resin; Polyether adhesive; Polyurethane adhesive; Epoxy resin; Phenol resin resin; Polyamide resin such as nylon 6, nylon 66, nylon 12, copolymer polyamide; polyolefin, acid-modified polyolefin, metal-modified polyolefin, etc. Polyolefin resin; polyvinyl acetate resin; cellulose adhesive; (meth) acrylic resin; polyimide resin; urea resin, melamine resin and other amino resins; chloroprene rubber, nitrile rubber, styrene - rubbers such as butadiene rubber, silicone resin; fluorinated ethylene propylene copolymer, and the like. These adhesive components may be used individually by 1 type, and may be used in combination of 2 or more type. The combination mode of two or more kinds of adhesive components is not particularly limited. For example, as the adhesive component, a mixed resin of polyamide and acid-modified polyolefin, a mixed resin of polyamide and metal-modified polyolefin, polyamide and polyester, Examples thereof include a mixed resin of polyester and acid-modified polyolefin, and a mixed resin of polyester and metal-modified polyolefin. Among these, it has excellent spreadability, durability under high humidity conditions, anti-hypertensive action, heat deterioration-suppressing action at the time of heat sealing, etc., and the lamination strength between the base material layer 1 and the metal layer 3 or the corrosion-resistant film 4b. From the viewpoint of effectively suppressing the occurrence of delamination by suppressing the decrease, preferably a polyurethane two-component curable adhesive; polyamide, polyester, or a blended resin of these with a modified polyolefin.

  The adhesive layer 2 may be multilayered with different adhesive components. When the adhesive layer 2 is multi-layered with different adhesive components, the adhesive component disposed on the base layer 1 side is selected from the viewpoint of improving the lamination strength between the base layer 1 and the metal layer 3 or the corrosion-resistant coating 4b. It is preferable to select a resin excellent in adhesiveness with the base material layer 1 and select an adhesive component excellent in adhesiveness with the metal layer 3 or the corrosion-resistant film 4b as the adhesive component disposed on the metal layer 3 side. When the adhesive layer 2 is multilayered with different adhesive components, specifically, the adhesive component disposed on the metal layer 3 side is preferably an acid-modified polyolefin, a metal-modified polyolefin, a polyester and an acid-modified polyolefin. And a resin containing a copolyester.

  About the thickness of the contact bonding layer 2, about 2-30 micrometers is mentioned, for example, Preferably about 3-15 micrometers is mentioned.

[Metal layer 3]
In the packaging material of the present invention, the metal layer 3 is a layer that functions as a barrier layer for preventing the penetration of water vapor, oxygen, light, and the like into the interior, in addition to improving the strength of the packaging material. Specific examples of the metal forming the metal layer 3 include metal foils such as aluminum, stainless steel, and titanium. Among these, aluminum foil is preferably used. In order to prevent wrinkles and pinholes during the production of the packaging material, soft aluminum such as annealed aluminum (JIS A8021P-O) or (JIS A8079P-O) is used as the metal layer 3 in the present invention. Is preferred.

  About the thickness of the metal layer 3, about 10-200 micrometers is preferable, for example, Preferably it is about 20-100 micrometers.

[Corrosion resistant coatings 4a, 4b]
Corrosion-resistant coatings 4a and 4b are used to stabilize adhesion between the metal layer 3 and a layer adjacent thereto (sealant layer 5, adhesive layer 6, adhesive layer 2, substrate layer 1, etc.), prevent dissolution and corrosion, etc. Therefore, it is a layer formed on the surface of the metal layer 3. In the present invention, the corrosion-resistant film 4a is provided between the metal layer 3 and the sealant layer 5 or an adhesive layer 6 described later. On the other hand, the corrosion-resistant film 4b is provided on the surface of the metal layer 3 opposite to the sealant layer 5 as necessary.

  Each of the corrosion-resistant films 4a and 4b can be formed by subjecting the surface of the metal layer 3 to a chemical conversion treatment with a treatment liquid containing a metal element. That is, the film formed on the surface of the metal layer 3 by the treatment liquid by the chemical conversion treatment becomes the corrosion resistant films 4a and 4b. The chemical conversion treatment can be performed, for example, by applying a treatment liquid for forming the corrosion-resistant films 4 a and 4 b to the surface of the metal layer 3.

  In the present invention, a preferable chemical conversion treatment includes chromate treatment. By the chromate treatment, corrosion-resistant films 4a and 4b containing chromium as a metal element are formed. Specific examples of chromate treatment include chromic acid using chromic acid compounds such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromic acid acetylacetate, chromium chloride, and potassium sulfate chromium. Chromate treatment; Phosphoric acid chromate treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; amination consisting of repeating units represented by the following general formulas (1) to (4) Examples thereof include chromate treatment using a phenol polymer.

In general formulas (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. R ¹ and R ² are the same or different and represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, C1-C4 linear or branched alkyl groups, such as a tert- butyl group, are mentioned. Examples of the hydroxyalkyl group represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, 3- A linear or branched chain having 1 to 4 carbon atoms substituted with one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group An alkyl group is mentioned. In the general formulas (1) to (4), X is preferably any one of a hydrogen atom, a hydroxyl group, and a droxyalkyl group. The number average molecular weight of the aminated phenol polymer composed of the repeating units represented by the general formulas (1) to (4) is, for example, about 500 to about 1,000,000, preferably about 1000 to about 20,000.

  As a specific example of the chemical conversion treatment, phosphoric acid is coated with a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, tin oxide or the like and fine particles of barium sulfate dispersed therein, and baked at 150 ° C. or higher. A method of forming a corrosion-resistant film on the surface of the metal layer 3 by performing the treatment is also mentioned. By these chemical conversion treatments, corrosion-resistant films 4a and 4b containing aluminum, titanium, cerium, tin, barium and the like as metal elements are formed.

  One type of chemical conversion treatment may be performed on the surface of the metal layer 3 alone, or two or more chemical conversion treatments may be performed in combination. Furthermore, these chemical conversion treatments may be carried out using one kind of compound alone, or may be carried out using a combination of two or more kinds of compounds. That is, each of the corrosion-resistant films 4a and 4b may be formed of one layer, or may be formed of a plurality of layers of the same or different types. Moreover, the composition of the corrosion-resistant films 4a and 4b may be the same or different.

  Among these, the corrosion resistant films 4a and 4b are preferably formed by chromate treatment, more preferably chromate treatment in which a chromate compound, a phosphoric acid compound, and an aminated phenol polymer are combined.

  In the present invention, the difference between the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant coating 4a in the width direction of the laminate constituting the packaging material (the direction perpendicular to the laminate direction) is A, When the average value of the content of the metal element contained in the corrosion resistant coating 4a in the width direction is B, the value calculated by Formula 1: A / B × 100 is 20% or less. From the viewpoint of more effectively suppressing deterioration due to acidic or alkaline contents in the packaging material of the present invention, the value calculated by the above formula 1 is preferably 15% or less, more preferably 10% or less. . Further, from the same viewpoint, the value calculated by the above formula 1 is most preferably 0%, but it is not always easy to set it to 0%, and is usually 2% or more.

From the viewpoint of more effectively suppressing deterioration due to acidic or alkaline contents in the packaging material of the present invention, the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant film 4a in the width direction of the laminate are determined. The difference A is preferably 0.3 mg / m ² or less, more preferably 0.2 mg / m ² or less. It is most preferable that the difference between the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant film 4a is 0 mg / m ^2, always be a 0 mg / m ² is not easy, the packaging of the present invention The difference in the material is usually 0.1 mg / m ² or more. For example, as shown in the schematic diagram of FIG. 5, when the corrosion resistant coatings 4a and 4b are sequentially formed in the length direction while the metal layer 3 moves in the length direction, the width direction of the laminate is The length direction z when the corrosion-resistant films 4a and 4b are formed is the vertical direction y. The vertical direction y coincides with an axial direction y of a roll 11 (described later) used for applying the treatment liquid for forming the corrosion-resistant films 4a and 4b.

From the viewpoint of more effectively suppressing deterioration due to acidic or alkaline contents in the packaging material of the present invention, the average value B of the content of metal elements contained in the corrosion-resistant coating 4a in the width direction of the laminate is preferably Is about 2.0 to 5.0 mg / m ² , more preferably about 2.5 to 3.5 mg / m ² , and still more preferably about 2.0 to 3.0 mg / m ² .

In the present invention, the difference A between the maximum value and the minimum value of the content of metal elements (for example, chromium element) contained in the corrosion-resistant film 4a, and the average value of the content of metal elements contained in the corrosion-resistant film 4a The ratio A / B with B can be calculated as follows. For example, as shown in FIG. 6, the distance from one end portion in the width direction y to the other end portion in the center portion in the length direction z of the packaging material in which the corrosion-resistant coating 4 a is laminated on the surface of the metal layer 3. Are cut out in a state in which the corrosion-resistant coating 4a and the metal layer 3 are laminated with a predetermined width at 5 locations (a1 to a5) that are 6%, 25%, 50%, 75%, and 94%, respectively. The content (distribution intensity) of the metal element to be measured contained in the corrosion-resistant film 4a at the location is measured using a fluorescent X-ray analyzer (XRF), and the ratio A / B is calculated from the distribution intensity of the metal element. . In the measurement of the content of the metal element contained in the corrosion-resistant film 4a by the fluorescent X-ray analyzer, first, the content X (strength) of the metal element is measured for the corrosion-resistant film 4a side on the metal layer 3. To do. Next, a portion on the metal layer 3 where the corrosion-resistant coating 4a is not formed (for example, a portion where the corrosion-resistant coating 4a is scraped off and the metal layer 3 is exposed, or a metal layer where neither of the corrosion-resistant coatings 4a and 4b is formed) 3), the content Y (strength) of the metal element is measured in the same manner. The difference between X and Y is the content (strength) of the metal element contained in the corrosion-resistant coating 4a.
Since the content of the metal element measured by the fluorescent X-ray analyzer is measured not as an actual mass value but as an intensity distribution, the ratio A / B is obtained by comparing the intensities measured at the five locations. Desired. As a fluorescent X-ray analyzer, for example, a fluorescent X-ray analyzer XRF-1800 manufactured by Shimadzu Corporation can be used. In addition, when measuring the actual value of the mass (mg / m ² ) of the metal element contained in the corrosion-resistant film 4a, the strength of the metal element is measured with a fluorescent X-ray analyzer for the corrosion-resistant film whose amount of the metal element is known. Can be measured, a calibration curve can be created for the relationship between mass and intensity, and the calibration curve can be calculated from the calibration curve.

  Moreover, in the packaging material of this invention, it calculates with said Formula 1 'of the corrosion-resistant film | membrane 4b provided as needed on the opposite side to the sealant layer 5 of the metal layer 3 in the width direction of the laminated body which comprises a packaging material. The value is preferably 20% or less, more preferably 15% or less, and still more preferably 5% or less. From the same point of view, the value calculated by the above formula 1 'is most preferably 0%, but it is not always easy to set it to 0%, and is usually 2% or more.

  Note that the difference between the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant film 4b in the width direction of the laminate is A ′, and the content of the metal element contained in the corrosion-resistant film 4b in the width direction of the laminate When the average value B ′ is set, the formula 1 ′ is set to A ′ / B ′ × 100. In addition, the ratio A ′ between the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant coating 4b, and the ratio of the average value B ′ of the content of the metal element contained in the corrosion-resistant coating 4b in the width direction of the laminate. A '/ B' and the calculation method of the actual measurement value of the mass are the same as those of the corrosion-resistant coating 4a.

From the viewpoint of more effectively suppressing deterioration due to acidic or alkaline contents in the packaging material of the present invention, the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant film 4b in the width direction of the laminate are determined. The difference A ′ is preferably 0.3 mg / m ² or less, more preferably 0.2 mg / m ² or less. It is most preferable that the difference between the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant film 4b is 0 mg / m ^2, always be a 0 mg / m ² is not easy, the packaging of the present invention The difference in the material is usually 0.1 mg / m ² or more.

From the viewpoint of more effectively suppressing deterioration due to acidic or alkaline contents in the packaging material of the present invention, the average value B ′ of the content of metal elements contained in the corrosion-resistant coating 4b in the width direction of the laminate is as follows: preferably 2.0~5.0mg / m ^2, more preferably about 2.5 to 3.5 mg / m ^2, and more preferably about include about 2.0~3.0mg / m ^2.

  In the packaging material of the present invention, a method of setting the value calculated by the above formulas 1, 1 ′ to 20% or less (further, the maximum value and the minimum value of the content of metal elements contained in the corrosion-resistant films 4a and 4b Difference between A, A ′ and the average value of the content of the metal element contained in the corrosion-resistant film is set to B and B ′ to the above values), the corrosion-resistant film forming step in the production method of the present invention described later is used. It is preferable to use it. As described later, in the conventional method, it was difficult to set the value calculated by the above formulas 1, 1 ′ to 20% or less. However, by adopting the manufacturing method of the present invention described later, the above formula is used. The value calculated by 1,1 ′ is 20% or less, and the difference A, A ′ between the maximum value and the minimum value of the content of metal elements contained in the corrosion-resistant coatings 4a and 4b and the metal contained in the corrosion-resistant coating It becomes possible to set the average value of element content to B and B ′ to the above values.

  A resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be formed on at least one of the corrosion-resistant films 4a and 4b. Here, as the cationic polymer, for example, polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin in which a primary amine is grafted on an acrylic main skeleton, polyallylamine, or Examples thereof include aminophenols and derivatives thereof. These cationic polymers may be used individually by 1 type, and may be used in combination of 2 or more type. Examples of the crosslinking agent include compounds having at least one functional group selected from the group consisting of isocyanate groups, glycidyl groups, carboxyl groups, and oxazoline groups, silane coupling agents, and the like. These crosslinking agents may be used alone or in combination of two or more.

[Sealant layer 5]
In the packaging material of the present invention, the sealant layer 5 is the innermost layer. By thermally welding the peripheral portions of the sealant layer 5, the packaging material becomes a bag-shaped packaging bag, and the contents can be accommodated inside the packaging bag.

  The sealant layer 5 is preferably formed of a polyolefin resin. The polyolefin resin is not particularly limited as long as it can be thermally welded, and examples thereof include polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin.

  Specific examples of the polyolefin include polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene; homopolypropylene, polypropylene block copolymer (for example, block copolymer of propylene and ethylene), polypropylene Polypropylenes such as random copolymers of (for example, random copolymers of propylene and ethylene); ethylene-butene-propylene terpolymers and the like. Among these polyolefins, polyethylene and polypropylene are preferable, and polypropylene is more preferable.

  The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Is mentioned. Examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, cyclic alkene is preferable, and norbornene is more preferable.

  The carboxylic acid-modified polyolefin is a polymer obtained by modifying the polyolefin by block polymerization or graft polymerization with carboxylic acid. Examples of the carboxylic acid used for modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride and the like.

  The carboxylic acid-modified cyclic polyolefin is obtained by copolymerizing a part of the monomer constituting the cyclic polyolefin in place of the α, β-unsaturated carboxylic acid or its anhydride, or α, β with respect to the cyclic polyolefin. -A polymer obtained by block polymerization or graft polymerization of an unsaturated carboxylic acid or its anhydride. The cyclic polyolefin to be modified with carboxylic acid is the same as described above. The carboxylic acid used for modification is the same as that used for modification of the acid-modified cycloolefin copolymer.

  Among these resin components, polyolefin and carboxylic acid-modified polyolefin are preferable, and polypropylene and carboxylic acid-modified polypropylene are more preferable.

  The sealant layer 5 may be formed of one kind of resin component alone, or may be formed of a blend polymer in which two or more kinds of resin components are combined. Furthermore, the sealant layer 5 may be formed of only one layer, but may be formed of two or more layers using the same or different resin components. As a preferable layer configuration when the sealant layer 5 is formed of two or more layers, for example, the outermost layer is formed of polypropylene and the layer on the metal layer 3 side is formed of carboxylic acid-modified polypropylene. Etc.

  Further, the thickness of the sealant layer 5 can be selected as appropriate, and is about 10 to 100 μm, preferably about 15 to 50 μm.

[Adhesive layer 6]
In the packaging material of the present invention, the adhesive layer 6 is a layer provided between the corrosion-resistant film 4a and the sealant layer 5 as necessary in order to firmly bond them.

  The adhesive layer 6 is formed of an adhesive capable of adhering the corrosion-resistant film 4a and the sealant layer 5. Regarding the adhesive used for forming the adhesive layer 6, the adhesive mechanism, the types of adhesive components, and the like are the same as those of the adhesive layer 2. The adhesive component used for the adhesive layer 6 is preferably a polyolefin-based resin, more preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene.

  About the thickness of the contact bonding layer 6, about 2-50 micrometers, for example, Preferably about 15-30 micrometers is mentioned.

3. Use of packaging material The packaging material of the present invention is used as a packaging material for containing contents. Specifically, the sealant layers at the periphery of the packaging material of the present invention can be heat sealed to form a bag-shaped packaging bag, and the contents can be accommodated in the packaging bag. When containing the contents using the packaging material of the present invention, the packaging material of the present invention is used so that the sealant layer is on the inner side (the surface in contact with the contents).

  The contents contained in the packaging material of the present invention are not particularly limited. However, as described above, the packaging material of the present invention is effectively prevented from being deteriorated by acidic or alkaline contents. May be acidic or alkaline. The contents may be any of solid, liquid, and gas at normal temperature, but usually contain liquid. Specific examples of the contents include chemicals, cosmetics, foods, electrolytes, and the like.

4). Manufacturing method of packaging material The manufacturing method of the packaging material of the present invention is a manufacturing method of a packaging material comprising a laminate in which at least a metal layer, a corrosion-resistant film formed on the surface of the metal layer, and a sealant layer are sequentially laminated. Using a roll having a crown shape whose outer diameter is maximum at the center in the axial direction and minimum at both ends, the coating amount is uniform in at least one of the surfaces of the metal layer in the width direction of the laminate. It is characterized by comprising applying a treatment liquid for forming a corrosion-resistant film so as to form a corrosion-resistant film on the surface and laminating the sealant layer on the corrosion-resistant film. .

  By adopting the production method of the present invention, it is possible to form the corrosion-resistant coating 4a so that the value calculated by the above formula 1 is 20% or less, which was difficult with the conventional method. Thus, a packaging material in which deterioration of the acidic or alkaline contents is effectively suppressed as in the packaging material of the present invention described above can be obtained. Similarly, by employing the manufacturing method of the present invention, it is possible to form the corrosion-resistant coating 4b so that the value calculated by the above formula 1 ′ is 20% or less. Further, the difference between the maximum and minimum values of the metal elements contained in the corrosion-resistant coatings 4a and 4b, A and A ′, and the average values of the metal elements contained in the corrosion-resistant coating are B and B ′ as described above. It is also possible to set to the value of.

  Conventionally, the chemical conversion treatment of the surface of the metal layer of the packaging material on which the metal layer is laminated is performed by a method of uniformly applying a treatment liquid for forming a corrosion-resistant film on the surface of the metal layer using a roll. However, when the amount of the metal element contained in the corrosion-resistant film is measured by a fluorescent X-ray analyzer (XRF) at a plurality of locations in the width direction of the packaging material (the axial direction of the roll to which the treatment liquid is applied), the corrosion-resistant film is obtained. It has been found that the amount of the metal element contained is uneven, and deterioration due to acidic or alkaline contents is likely to occur at locations where the amount of the metal element is small. It was thought that the thickness of the treatment liquid was almost uniformly formed by the roll, but actually, a slight thickness unevenness occurred, and this unevenness caused the metal element contained in the corrosion-resistant film. It is considered that there is a difference in quantity.

  On the other hand, in the manufacturing method of the present invention, in the above-described corrosion-resistant film forming step, as a roll for applying the corrosion-resistant film, instead of a generally used cylindrical roll having the same outer diameter in the axial direction, A roll 11 having a crown shape in which the outer diameter is maximum at the central portion in the axial direction and minimum at both ends as shown in FIG. 4 is used. Accordingly, in the present invention, in the width direction of the packaging material, the uniformity of the amount of the metal element contained in the corrosion-resistant coating 4a is enhanced, and a packaging material in which deterioration due to acidic or alkaline contents is suppressed is obtained. .

  In the production method of the present invention, the roll 11 used for forming the corrosion-resistant film 4a in the corrosion-resistant film formation step has a crown shape as shown in FIG. 4, for example, and the outer diameter is the central part in the axial direction. At the maximum and minimum at both ends. That is, the roll 11 satisfies the relationship of “diameter X1 of the circular cross section at the center in the axial direction”> “diameter X2 of the circular cross section at both ends”.

  The crown amount of the roll 11 (difference between the outer diameter at the central portion and the outer diameter at both ends in the axial direction) is appropriately set according to the width of the metal layer 3 forming the corrosion-resistant coating 4a. For example, when the width of the metal layer 3 is about 600 to 900 mm, the crown amount is preferably about 0.1 to 0.15 mm, more preferably about 0.1 to 0.12 mm.

  In the corrosion-resistant film forming step, the roll 11 having a crown shape plays a role of adjusting the coating amount of the treatment liquid for forming the corrosion-resistant film 4a to be uniform. When applying the treatment liquid in a uniform application amount using the roll 11, for example, the treatment liquid is supplied to the surface of the roll 11 and the metal layer 3 while rotating the roll 11 relative to the surface of the metal layer 3. The amount of treatment liquid applied to the surface of the metal layer 3 may be adjusted uniformly by pressing. Further, for example, by supplying a treatment liquid to the surface of the metal layer 3 in advance and then pressing the roll 11 against the surface of the metal layer 3 while rotating the treatment liquid, the treatment liquid is uniformly applied to the surface of the metal layer 3. You may apply | coat by the application quantity. The same applies to the corrosion-resistant coating 4b.

  Examples of the method for supplying the treatment liquid to the surface of the metal layer 3 in advance include a method of immersing the metal layer 3 in the treatment liquid. Specifically, in the corrosion-resistant film forming step, after the metal layer 3 is immersed in a treatment liquid for forming the corrosion-resistant film 4a, a treatment liquid on at least one surface of the metal layer 3 is applied using a roll having a crown shape. By adjusting the amount so as to be uniform in the width direction of the laminate, the corrosion-resistant coating 4a can be formed on the surface. The corrosion resistant coating 4b can be formed in the same manner.

  Moreover, it does not restrict | limit especially as a pressure at the time of pressing the surface of the metal layer 3 with the roll 11, However, From a viewpoint of improving the uniformity of the coating amount of a process liquid, Preferably it is about 0.2-0.5 MPa. It is done.

  After forming the film of the treatment liquid, the metal layer 3 may be heated so as to have a temperature of about 70 to 200 ° C., if necessary. For example, as shown in the schematic diagram of FIG. 5, the metal layer 3 immersed in the treatment liquid 10 is heated using the heating unit 11 after the application amount of the treatment liquid is adjusted using the roll 11. May be. The heating means 12 is not particularly limited, and a known heater or the like can be used. In addition, before the chemical conversion treatment is performed on the metal layer 3, the metal layer 3 may be subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like in advance. By performing the degreasing treatment in this way, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the metal layer 3.

  The treatment liquid is not particularly limited as long as it can form a corrosion-resistant film having corrosion resistance against acids or alkalis. For example, the same treatment liquid described in the packaging material of the present invention is used for the above chemical conversion treatment. Things.

  In the case of forming the corrosion-resistant films 4a and 4b on both surfaces of the metal layer 3, in the corrosion-resistant film forming process, the treatment liquid is passed between the two rolls 11 having a crown shape and the metal layer 3 coated on both surfaces is passed. However, it is preferable to adjust the coating amount of the treatment liquid in the width direction of the laminate to form the corrosion-resistant films 4 a and 4 b on both surfaces of the metal layer 3. Thereby, not only the corrosion resistant film 4a but also the corrosion resistant film 4b, the value calculated by the above formulas 1 and 1 ′ can be 20% or less, and further, the metal elements contained in the corrosion resistant films 4a and 4b. The difference A, A ′ between the maximum value and the minimum value of the content of B and the average value of the content of the metal element contained in the corrosion-resistant film are set to B and B ′ are the values calculated above, and the corrosion-resistant film 4a and 4b can be formed, whereby the adhesion between the metal layer 3 and the base material layer 1 or the adhesive layer 2 can be further stabilized.

  Next, the sealant layer 5 is laminated on the metal layer 3 on which the corrosion-resistant film 4a is formed. When the sealant layer 5 is directly laminated on the corrosion-resistant film 4a, the resin component constituting the sealant layer 5 may be applied on the corrosion-resistant film 4a by a method such as a gravure coating method or a roll coating method. When the adhesive layer 6 is provided between the corrosion-resistant film 4a and the sealant layer 5, for example, (1) a method of laminating the adhesive layer 6 and the sealant layer 5 on the corrosion-resistant film 4a by coextrusion (co- (Extrusion lamination method), (2) Separately, a laminate in which the adhesive layer 6 and the sealant layer 5 are laminated, and this is laminated on the corrosion resistant film 4a by the thermal lamination method. (3) On the corrosion resistant film 4a, An adhesive for forming the adhesive layer 6 is laminated by an extrusion method, a solution-coated high temperature drying or baking method, and the sealant layer 5 previously formed into a sheet shape on the adhesive layer 6 by a thermal lamination method. 4. Lamination method (4) The molten adhesive layer 6 is poured between the corrosion-resistant film 4a and the sealant layer 5 previously formed into a sheet shape, and the adhesive layer 6 is used for resistance. Like sex film 4a and a method of bonding a sealant layer 5 (sand lamination method). In addition, in order to strengthen the adhesiveness of each layer, you may use for heat processing, such as a hot roll contact type, a hot air type, a near or far-infrared type, further. Examples of such heat treatment conditions include 150 to 250 ° C. for 1 to 5 minutes.

  In the production method of the present invention, when the base layer 1, the adhesive layer 2 and the like are provided on the opposite side of the metal layer 3 from the sealant layer 5, the metal layer on which the corrosion-resistant film 4a and, if necessary, the corrosion-resistant film 4b are formed. 3 is manufactured as described above, and using this, a laminated body in which the base material layer 1, the adhesive layer 2, and the metal layer 3 are laminated in order (hereinafter sometimes referred to as “laminated body A”) is prepared. Form. Specifically, the laminate A is formed by an extrusion method, gravure, using an adhesive used for forming the adhesive layer 2 on the metal layer 3 on which the corrosion-resistant film 4b is formed or on the base material layer 1 if necessary. After applying and drying by a coating method such as a coating method or a roll coating method, it can be performed by a dry lamination method in which the metal layer 3 or the substrate layer 1 is laminated and the adhesive layer 2 is cured. A packaging material can be manufactured by laminating the sealant layer 5 as described above on the corrosion-resistant film 4a of the obtained laminate A.

  In the packaging material of the present invention, each layer constituting the laminate is improved or stabilized as necessary, for example, film forming property, lamination processing, final product secondary processing (pouching, embossing) suitability, etc. Surface activation treatment such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

Test example 1
As shown in the schematic diagram of FIG. 5, after immersing an aluminum foil (length: 3,000 m, width: 840 mm, thickness: 40 μm) as a metal layer in the following treatment liquid for forming a corrosion-resistant film, The treatment liquid was uniformly applied to both sides of the aluminum foil in the width direction by passing between two rolls described below and adjusting the application amount of the treatment liquid formed on the aluminum foil. Next, the coating film of the treatment liquid was baked under the condition that the coating temperature was about 180 ° C. to form a corrosion-resistant coating.
As the treatment liquid, an aqueous solution of a phenol resin (12.5% by mass), a chromium fluoride compound (30.0% by mass), and phosphoric acid (12.5% by mass) was used. The pressure of the roll applied to the metal layer when passing between the two rolls was 0.3 MPa, respectively. In addition, the density | concentration of the process liquid and the pressure of the roll were set so that the application quantity of chromium might be 3.2-4.0 mg / m < ² > (dry weight).
As the roll, the surface is formed of rubber, the axial length is 950 mm, the outer diameter of the central part is φ120.12 mm, the outer diameters of both ends are φ120 mm, the outer diameter is the maximum in the central part in the axial direction, A roll having a crown shape that is the smallest at both ends (crown amount is 0.12 mm) was used.

Next, in the corrosion resistant coating formed on both surfaces of the metal layer, the amount of chromium element contained in the corrosion resistant coating was measured at five locations at equal intervals in the width direction (the measurement locations were in the length direction of the packaging material). (In the central portion, the distance from the one side end to the other end in the width direction is 50 mm, 210 mm, 420 mm, 630 mm, and 790 mm in this order). The amount of chromium element in the corrosion-resistant film was measured at each measurement location with respect to the metal layer on which the corrosion-resistant film was formed, using the fluorescent X-ray analyzer XRF-1800 manufactured by Shimadzu Corporation by the above method. The content of chromium element contained in the metal layer was measured for the aluminum foil used as the metal layer. The results of the corrosion-resistant film on the sealant layer side are shown in Table 1 and the graph of FIG. 7, and the results of the corrosion-resistant film on the base material layer side are shown in Table 2 and the graph of FIG. In addition, the measured value of the mass (mg / m ² ) of the chromium amount in each test example is obtained by measuring the strength of the chromium element with a fluorescent X-ray analyzer with respect to the corrosion-resistant film with the known chromium amount. A calibration curve is created for the relationship, and is a value calculated from the calibration curve.

Test example 2
The formation of the corrosion-resistant film on the metal layer was repeated under the same conditions as in Test Example 1, and the amount of chromium element contained in the corrosion-resistant film was measured in the same manner as in Test Example 1 for the 40th corrosion-resistant film. The results of the corrosion-resistant film on the sealant layer side are shown in Table 1 and the graph of FIG. 7, and the results of the corrosion-resistant film on the base material layer side are shown in Table 2 and the graph of FIG.

Comparative Test Example 1
As a roll, a cylindrical roll whose surface is formed of rubber, has an axial length of 950 mm, and the same outer diameter in the axial direction is φ120 mm, and the pressure applied to the metal layer is 0.5 MPa. Formed a corrosion-resistant film in the same manner as in Test Example 1 and measured the amount of chromium element contained in the corrosion-resistant film. The results of the corrosion-resistant film on the sealant layer side are shown in Table 1 and the graph of FIG. 7, and the results of the corrosion-resistant film on the base material layer side are shown in Table 2 and the graph of FIG.

  As is clear from Tables 1, 2 and 7 and 8, in Test Example 1 in which a corrosion-resistant film was formed using a roll having a crown shape, the uniformity of the chromium element content in the width direction of the corrosion-resistant film. Is high. Further, in Test Example 2 in which the corrosion resistant film was formed 40 times under the same conditions as in Test Example 1 and the amount of chromium element of the corrosion resistant film formed in the 40th time was measured, the content of chromium element in the width direction of the corrosion resistant film was high. It can be seen that high uniformity is maintained even when the corrosion resistance film is continuously formed with high uniformity. On the other hand, as in the prior art, in Comparative Test Example 1 in which a corrosion-resistant film was formed using a cylindrical roll having the same outer diameter in the axial direction, the uniformity of the chromium element content in the width direction of the corrosion-resistant film was tested. It can be seen that it is lower than Example 1 and Test Example 2.

Example 1
<Manufacture of packaging materials>
A chemical conversion treatment was performed on both surfaces of an aluminum foil (thickness 40 μm) as a metal layer in the same manner as in Test Example 1 to form a corrosion-resistant film. Next, a nylon film (thickness: 25 μm) as a base material layer was bonded to one of the chemical conversion treated surfaces by a dry laminating method through a polyester adhesive so that the thickness of the adhesive layer was about 3 μm. Next, a polyolefin resin for forming a sealant layer (thickness 46 μm) is extruded on the chemical conversion treatment surface of the other aluminum foil to form a base material layer / adhesive layer / corrosion resistance film / aluminum foil / corrosion resistance film / sealant layer. A laminate was obtained.

Comparative Example 1
<Manufacture of packaging materials>
Except that the metal layer was subjected to chemical conversion treatment in the same manner as in Comparative Test Example 1, it was composed of a base material layer / adhesive layer / corrosion resistant film / aluminum foil / corrosion resistant film / sealant layer as in Example 1. A laminate was obtained.

<Corrosion resistance evaluation>
The packaging materials obtained in Example 1 and Comparative Example 1 were cut into strips having a length of 100 mm and a width of 15 mm to obtain test pieces. The test piece was immersed in an electrolytic solution (mixed solution of 1M LiPF ₆ and ethylene carbonate, diethyl carbonate and dimethyl carbonate (volume ratio 1: 1: 1)), stored at 85 ° C. for 1 day, and then the metal layer. The laminate strength between the sealant layer and the sealant layer was measured (n = 5). The laminate strength is measured at 25 ° C. and 50% relative humidity in an environment where the test piece is immersed in the electrolyte solution and the metal layer is measured with a tensile tester (manufactured by Shimadzu Corp., AGS-50D (trade name)). The sealant layer was peeled 10 mm at a speed of 50 mm / min, and the maximum strength at the time of peeling was defined as the laminate strength. The results are shown in Table 3.

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesive layer 3 Metal layer 4 Corrosion-resistant film 5 Sealant layer 6 Adhesive layer 10 Treatment liquid 11 Roller 12 Heater

Claims (10)

At least a metal layer, a corrosion-resistant film formed on the surface of the metal layer, and a laminate in which a sealant layer is sequentially laminated,
The metal layer has a thickness of 10 to 200 μm,
The average value B of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate is in the range of 2.0 to 5.0 mg / m ² ,
A is the difference between the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate, and the average of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate A packaging material in which the value calculated by the following formula 1 is 20% or less when the value is B.
Formula 1: A / B × 100 The packaging material according to claim 1 , wherein a corrosion-resistant film is further formed on a surface of the metal layer opposite to the sealant layer. The packaging material according to claim 1 or 2 , wherein the metal element is chromium, aluminum, titanium, cerium, tin, or barium. The packaging material according to any one of claims 1 to 3 , wherein a thickness of the sealant layer is in a range of 10 to 100 µm. The packaging material in any one of Claims 1-4 by which a base material layer is laminated | stacked on the opposite side to the said sealant layer of the said metal layer. At least a method for producing a packaging material comprising a laminate in which a metal layer, a corrosion-resistant film formed on the surface of the metal layer, and a sealant layer are sequentially laminated,
The metal layer has a thickness of 10 to 200 μm,
The average value B of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate is in the range of 2.0 to 5.0 mg / m ² ,
Using a roll having a crown shape whose outer diameter is maximum at the center in the axial direction and minimum at both ends, the coating amount is uniform in at least one of the surfaces of the metal layer in the width direction of the laminate. Applying a treatment liquid for forming the corrosion-resistant film, and forming a corrosion-resistant film on the surface;
Laminating the sealant layer on the corrosion-resistant film;
A method for producing a packaging material. In the corrosion-resistant film forming step, after immersing the metal layer in a treatment liquid for forming the corrosion-resistant film, a roll having the crown shape is used, and the coating amount of the treatment liquid on at least one surface of the metal layer is The manufacturing method of the packaging material of Claim 6 which adjusts so that it may become uniform in the width direction of the said laminated body, and forms the said corrosion-resistant film | membrane on the said surface. In the corrosion-resistant film forming step, using a roll having the crown shape,
A is the difference between the maximum value and the minimum value of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate, and the average of the content of the metal element contained in the corrosion-resistant film in the width direction of the laminate The method for producing a packaging material according to claim 6 or 7 , wherein when the value is B, the corrosion-resistant film is formed such that a value calculated by the following formula 1 is 20% or less.
Formula 1: A / B × 100 In the corrosion-resistant film forming step, the treatment liquid is applied in the width direction of the laminate while passing the metal layer coated on both surfaces between the two rolls having the crown shape. The manufacturing method of the packaging material in any one of Claims 6-8 which adjusts so that it may become uniform and forms a corrosion-resistant film | membrane on both surfaces of the said metal layer. The method for manufacturing a packaging material according to any one of claims 6 to 9 , wherein the metal element is chromium, aluminum, titanium, cerium, tin, or barium.