WO2022059599A1

WO2022059599A1 - Aluminum can for filling with wine

Info

Publication number: WO2022059599A1
Application number: PCT/JP2021/033214
Authority: WO
Inventors: 諭鬼頭; 悦子八百井; 千晶吉野
Original assignee: 東洋製罐株式会社
Priority date: 2020-09-15
Filing date: 2021-09-09
Publication date: 2022-03-24
Also published as: JP2022048919A; TW202218955A

Abstract

The present invention relates to an aluminum can for filling with wine. In the present invention, a can formed from an aluminum can body having a polyester resin coating on a can inner surface, and an aluminum can lid that covers an opening in the aluminum can body, is filled with wine having a pH of 3.0-4.0 and a sulfur dioxide molecule content of 1.9 mg/L or less, whereby even when a container is filled with a wine that contains sulfites and is hermetically sealed, corrosion of the container and loss of flavor of the wine are effectively prevented without using a special scavenger for scavenging sulfurous acid.

Description

Aluminum cans for filling wine

The present invention relates to an aluminum container for filling wine, and more specifically, even when wine containing sulfite as an antioxidant is filled and sealed, the container is corroded and the flavor of wine is impaired. With respect to aluminum cans for wine filling, which are effectively suppressed.

Since wine is easily oxidized and its flavor is easily impaired by oxidation, it is generally stored and distributed in a glass bottle that does not allow oxygen to pass through. On the other hand, since glass bottles are heavy and vulnerable to impact, it is desired that wine be filled and sealed in a lightweight and impact-resistant container.
Similar to glass bottles, metal containers have excellent gas barrier properties and also have light-shielding properties. Therefore, it has been proposed to fill and seal wine in metal containers. However, wine generally contains a sulfite salt as an antioxidant, and since this sulfite is highly corrosive to metals, there is a problem that the metals are corroded.

In order to solve such a problem of a metal container, Patent Document 1 below suppresses corrosion and flavor deterioration of a metal can by reducing the sulfurous acid concentration in wine to 50 ppm or less.
Further, in the aluminum container for wine disclosed in Patent Document 2, a polyester resin coating is formed on the inner surface of the body of the can body, and a coating film made of polyester / phenol-based paint is formed on the inner surface of the can lid. This container can be filled with wine having a free sulfurous acid concentration of 50 ppm or more. In the examples, wine having a maximum free sulfurous acid concentration of 80 ppm is filled.

Sulfites added to wine are present in the form of monovalent sulfite ion HSO _3- ^or sulfur dioxide molecule SO ₂ in an acidic solution such as wine. Of the two, sulfur dioxide molecules are more likely to permeate the resin coating and have a greater adverse effect on corrosion. Therefore, the sulfur dioxide molecule content in wine is important in the manufacture of aluminum cans for filling wine.

Patent Document 3 defines the sulfur dioxide molecule content in wine. That is, the document is characterized in that wine having a pH of 2.9 to 3.5 and a sulfur dioxide molecule content of 0.4 to 0.8 mg / L is filled, and further, the wine is subjected to multi-step microfiltration treatment before filling. Disclosed is a wine-filled container characterized by being microfiltered in.

Japanese Unexamined Patent Publication No. 2-76565 Japanese Unexamined Patent Publication No. 2019-131275 Special Table 2015-500650

In Patent Document 3, by removing microorganisms and the like by microfiltration, the content of sulfur dioxide molecules functioning as antioxidants and bactericides is suppressed to a low level of 0.4 to 0.8 mg / L to prevent corrosion. .. However, microfiltration has poor work efficiency and increases costs.

Therefore, an object of the present invention is to provide an aluminum container (can) for filling wine and a packaged wine that can effectively prevent corrosion of cans and deterioration of wine quality without suppressing the content of sulfur dioxide molecules to a low level. That is.

According to the present invention, it is composed of an aluminum can body having at least a polyester resin coating on the inner surface of the can and an aluminum can lid covering the opening of the aluminum can body, and has a pH of 3.0 to 4.0 and sulfur dioxide molecules. Provided are aluminum cans for filling wine, which are characterized by filling wine having a content of 1.9 mg / L or less.

In the aluminum can for wine filling of the present invention,
1. 1. The sulfur dioxide molecule content is 0.4 to 1.9 mg / L.
2. 2. A coating film made of polyester / phenolic paint is formed on at least the inner surface side of the aluminum can lid.
3. 3. The thickness of the body of the polyester resin coating is in the range of 4 to 30 μm.
4. The thickness of the coating film on the can lid is in the range of 6 to 20 μm.
5. The polyester resin coating is made of an ethylene terephthalate polyester resin.
6. The polyester / phenol-based paint is formed from a paint composition containing a polyester resin as a main component and a resole-type phenol resin as a curing agent.
7. The can body is a seamless can.
8. The can lid is a stayion tab type easy open can lid.
Is preferable.

According to the present invention, the aluminum can for filling wine is filled and sealed with wine having a pH of 3.0 to 4.0 and a sulfur dioxide molecule content of 0.4 to 1.9 mg / L. Aluminum canned wine is provided.

In the aluminum can for filling wine of the present invention, the permeation of sulfur dioxide molecules is suppressed by the inner surface coating made of a polyester resin film provided on the inner surface of the can body and the polyester / phenol-based inner surface coating film provided on the inner surface of the can lid. Therefore, it is possible to effectively prevent the corrosion of aluminum and the deterioration of flavor over a long period of time.
Further, the aluminum can for wine filling of the present invention is excellent in that it is not necessary to add a scavenger for capturing sulfurous acid to the inner surface coating and the inner surface coating film, and it is squeezed because it is excellent in adhesion. It is also excellent in that it does not cause poor adhesion of the resin coating even by harsh processing such as ironing.
Furthermore, since the highly reactive organic component hardly elutes from the resin coating, it is possible to effectively prevent the flavor from deteriorating.

The effect of the present invention is also clear from the results of Examples described later (Table 1). That is, in the example in which the can lid Z was attached to the can body X, when the sulfur dioxide molecule content was 1.9 mg / L or less, no noticeable corrosion occurred in either the can body X or the can lid Z. Further, regarding the can body X, corrosion did not occur even in the case of white wine L having a sulfur dioxide molecule content of 3.4 mg / L.

According to the examples, white wine L was filled and sealed, and the inner surface (a) of the can body X, the inner surface (b) of the can body Y, and the can body X after 6 months had passed under a constant temperature condition of 23 ° C. It is a photograph of the inner surface (c) of the attached can lid Z. It is a photograph of the can body inner surface (a) of the can body X and the can body inner surface (b) of the can body Y after 6 months have passed under the constant temperature condition of 23 ° C. after filling and sealing the white wine M according to the examples. It is a photograph of the rivet-processed portion of the can lid Z mounted on the can body X after 6 months have passed under the constant temperature condition of 23 ° C. by filling and sealing the white wine N according to the examples.

(Aluminum can for filling wine)
The aluminum can for wine filling of the present invention comprises an aluminum can body and an aluminum can lid covering the opening of the can body.

[Aluminum can body]
A polyester resin coating having a thickness in the range of 4 to 30 μm is preferably formed on the inner surface of the body of the aluminum can body. If the thickness of the resin coating on the inner surface of the can body is thinner than the above range, the permeation of the resin coating of sulfurous acid ions and sulfur dioxide molecules cannot be suppressed, causing corrosion and deterioration of flavor. There is a risk. On the other hand, when the thickness of the resin coating on the inner surface of the body of the can body is thicker than the above range, not only the economic efficiency is inferior, but also the adhesion of the resin coating may be poor during molding.

The shape and molding method of the aluminum can body used in the aluminum can for wine filling of the present invention is not particularly limited as long as the body of the can body has a polyester resin coating, but the polyester resin coated aluminum metal plate is particularly limited. It is preferable that the can is a seamless can molded so that the polyester resin coating is on the inner surface.
The thickness of the polyester resin coating specified in the present invention is the thickness of the portion where the resin coating is the thinnest in the can body, and in the seamless can formed by drawing, ironing, etc., the polyester resin coated metal plate is the thinnest. It is the thickness of the body of the can body, which is the thinnest in the polyester resin coating due to the harsh molding process.

The polyester resin-coated aluminum plate used for molding the aluminum can body of the present invention is formed by coating at least the inner surface of the can with a polyester resin described later.
As the aluminum plate, an aluminum plate made of pure aluminum or an aluminum alloy (in the present specification, the aluminum plate including the aluminum alloy plate is referred to as an “aluminum plate”) can be used.
It is preferable that the aluminum plate is subjected to a conventionally known surface treatment in order to improve the adhesion to the resin coating and the corrosion resistance, and the aluminum plate is not limited to this, but is a phosphoric acid chromate treatment and an organic containing Zr (zylconium). It is preferable that the aluminum plate is subjected to surface treatment such as inorganic surface treatment.
It is desirable to use an aluminum plate having a thickness of 0.15 to 0.40 mm, particularly 0.20 to 0.30 mm.

As the polyester resin constituting the polyester resin coating applied to the aluminum plate, 80 mol% or more, particularly 90 mol% or more of the carboxylic acid component is composed of the terephthalic acid component, and 80 mol% or more, particularly 90 mol% of the alcohol component. The above is preferably an ethylene terephthalate-based polyester resin made of ethylene glycol (hereinafter, may be simply referred to as “PET resin”). This polyester resin may be a homopolyethylene terephthalate, a copolymerized polyester, or a blend resin of two or more of these.

Examples of the carboxylic acid component other than the terephthalic acid component include isophthalic acid, naphthalenedicarboxylic acid, p-β-oxyethoxybenzoic acid, biphenyl-4,4'-dicarboxylic acid, diphenoxyetane-4,4'-dicarboxylic acid, 5 -Sodium sulfoisophthalic acid, hexahydroterephthalic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid, hemmellitic acid, 1,1,2,2-ethanetetracarboxylic acid, 1,1,2-ethanetricarboxylic acid Acids, 1,3,5-pentantricarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, biphenyl-3,4,3', 4'-tetracarboxylic acid, dimer acid and the like can be mentioned. In particular, it is preferable to contain isophthalic acid and dimer acid.
On the other hand, as alcohol components other than ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, cyclohexanedimethanol, bisphenol A ethylene oxide adduct, etc. Alcohol components such as glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitan can be mentioned.
The polyester resin should have a molecular weight within the film forming range, and the intrinsic viscosity (IV) measured using a phenol / tetrachloroethane mixed solvent as a solvent is 0.55 dL / g or more, particularly 0.6 to 1.0 dL /. It is good that it is in the range of g in terms of barrier property against corrosive components and mechanical properties.

The polyester resin coating may be not limited to a single layer but may be multi-layered, but the surface layer is a homo-PET or copolymer PET having an isophthalic acid content of 5 mol% or less, and the lower layer has an isophthalic acid content of 5. It may be composed of a copolymerized PET having an amount of about 15 mol% and a dimer acid content of 1 to 6 mol%, and may have a two-layer structure in which the thickness ratio of the surface layer to the lower layer is in the range of 2: 8 to 8: 2.

Further, when the aluminum can body is formed by drawing / bending / stretching and / or ironing, the thickness of the polyester resin coating should be in the range of 8 to 30 μm in the state of the polyester resin coated aluminum plate. It is preferable to set the thickness of the polyester resin inner surface coating of the molded can body in the body to the above range. When the polyester resin coating has multiple layers, it is preferable that the total thickness is within the above thickness range.
Further, the polyester resin can be coated on the aluminum plate by a conventionally known laminating method, and an adhesive is preferably used by lamination of a cast film (multilayer cast film) or by an extrusion coat (co-extrusion coat). Of course, the use of an adhesive is not limited, and a conventionally known adhesive primer can also be used for adhesion to an aluminum plate.
A conventionally known paint for cans or a polyester resin coating can be formed on the outer surface side of the polyester resin-coated aluminum plate without limitation.

In the present invention, the above-mentioned polyester resin-coated aluminum plate is subjected to conventionally known means such as drawing / re-drawing, drawing / bending / stretching, drawing / bending / stretching / ironing, or drawing / ironing. It can be produced by the above, and in particular, it is preferably formed from drawing / bending / stretching and / or ironing. To thin the can body, the body is bent and stretched and / or ironed so that the thickness of the polyester resin-coated aluminum plate is 20 to 95%, especially 30 to 85%. It is preferable to have.
The molded can body is trimmed, heat-treated, neck-in processed, flanged, and if necessary, printed on the outer surface of the can body by a conventionally known method to obtain a seamless can for tightening the can lid, which will be described later. be able to.

[Aluminum can lid]
It is preferable that a coating film made of polyester / phenol-based paint is formed on the inner surface of the aluminum can lid. The shape and molding method of the polyester / phenol-based coating film are not particularly limited.

The thickness of the polyester / phenol-based coating film is preferably 6 to 20 μm. When the thickness of the polyester / phenol-based coating film is thinner than the above range, the permeation of the resin coating of sulfurous acid ions and sulfur dioxide molecules cannot be suppressed as in the case of the inner surface of the can body body, causing corrosion or flavor property. May decrease. On the other hand, when the thickness of the polyester / phenol-based coating film is thicker than the above range, not only is it inferior in economic efficiency, but also a normal coating film cannot be formed due to paint dripping and generation of blister during coating film formation. As a result, it may not be possible to form a coating film capable of suppressing the permeation of sulfite ions and sulfur dioxide molecules.
The painted aluminum plate having a polyester / phenol-based coating film used for molding an aluminum can lid contains a polyester resin as a main agent and a phenol resin as a curing agent in the aluminum plate used for molding an aluminum can body described above. It is made by applying a coating composition to be used.

In the present invention, the coating composition capable of forming the polyester / phenol-based coating film is not particularly limited as long as it is a coating composition containing a polyester resin as a main agent and a phenol resin as a curing agent.
For example, but not limited to this, a carboxyl group-containing aromatic polyester resin and metacresol having an acid value of 10 to 30 mgKOH / g and a number average molecular weight of 3000 to 10000 described in JP-A-2003-321646. A water-based coating composition containing a phenol resin derived from, or a polyester having an acid value of 2 to 50 mgKOH / g and a glass transition temperature (Tg) of 35 to 100 ° C. described in JP2013-249376A. A mixed polyester resin obtained by mixing the resin (A) with a polyester resin (B) having an acid value of 0 to 50 mgKOH / g and a glass transition temperature (Tg) of −20 to 25 ° C., and a solid resin of the mixed polyester resin. A coating composition containing 1 to 30 parts by weight of a resol-type phenol resin per 100 parts by weight of a portion and a curing catalyst in an amount of 0.1 to 3.0 parts by weight with respect to 100 parts by weight of the total resin solid content. Can be preferably used.

In the present invention, as described above, it is preferable to apply this coating composition to an aluminum plate so that the coating thickness is 6 to 20 μm. As the aluminum plate to be used, the same one used for the aluminum can body can be used.
The coating method of the coating composition on the aluminum plate is not particularly limited, and coating can be performed by any conventionally known coating method, for example, spray coating, roll coater coating, dip coating, or the like. The baking conditions for the coating film are generally preferably 100 to 300 ° C. for 5 seconds to 30 minutes, preferably 150 to 270 ° C. for 15 seconds to 15 minutes.

The aluminum can lid used in the present invention can be molded by a molding method known per se, except that the lid material described above is used. That is, the painted aluminum plate can be punched into a predetermined shape and size, and then molded into the shape of a lid by a press die. The aluminum lid used in the present invention is not limited to this, but is a stain tab (SOT) type easy open lid, a fully open type easy open lid, or the like, and a SOT lid is particularly preferable.

(Wine in a container)
The packaged wine of the present invention is formed by filling and sealing wine in a can (container) made of the above-mentioned aluminum can body and aluminum can lid, and as described above, contains sulfite as an antioxidant. Even if the wine is brewed, there is no internal corrosion of the container and the flavor of the wine is not impaired for a long period of time. As for the type of wine, conventionally known wines such as red, white, rosé, and sparkling can be filled without limitation.

As mentioned above, the sulfite added to wine is present in the form of monovalent sulfite ion HSO _3- ^or sulfur dioxide molecule SO ₂ in an acidic solution such as wine. Of the two, sulfur dioxide molecules are more likely to permeate the resin coating and have a greater adverse effect on corrosion. Therefore, the sulfur dioxide molecule content in wine is important in the manufacture of aluminum cans for filling wine.
The acid dissociation constant pKa 1.78 of sulfurous acid is used to calculate the sulfur dioxide molecule content. That is, the sulfur dioxide molecule content can be calculated using the following formula.
pH = pKa + log ([HSO _3- ^] / [SO ₂ · H ₂ O])
pH: wine pH
pKa: pKa of sulfite
[HSO _3- ^] : Sulfite ion concentration (mol / L)
[SO ₂ · H ₂ O]: Sulfur dioxide molecular concentration (mol / L)

The aluminum can for wine filling of the present invention can be filled up to a sulfur dioxide molecule content of 1.9 mg / L. This means that even a content exceeding the sulfur dioxide molecule content in the prior art (for example, 0.4 to 0.8 mg / L in Patent Document 3) can be filled.

(Making a can)
As the aluminum plate, a phosphoric acid chromate surface-treated aluminum plate (plate thickness 0.28 mm) was used.
This surface-treated aluminum plate was heated to 250 ° C., a polyester resin film was thermocompression-bonded on both sides thereof via a laminate roll, and then immediately cooled with water to prepare a polyester resin-coated aluminum plate. As the polyester resin film on the inner surface side of the can, a copolymerized PET resin film having a thickness of 16 μm and an isophthalic acid content of 10 mol% was used, and on the outer surface side of the can, an isophthalic acid content of 10 μm thickness was 12 mol%. The copolymerized PET resin film of the above was used.
Paraffin wax was electrostatically applied to both sides of the obtained polyester resin-coated aluminum plate, and then punched into a circle having a diameter of 156 mm to prepare a shallow drawn cup. Next, this shallow drawn cup is re-squeezed-ironed and domed, trimmed at the edge of the open end, heat-treated at 201 ° C. for 75 seconds, and then heat-treated at 210 ° C. for 80 seconds, and the open end is necked. , Franging was performed to prepare a can body X which is a seamless can made of polyester resin-coated aluminum having a can body of 211 diameter and a neck portion of 206 diameter and a capacity of 500 ml.
The can body X has a can body diameter of 66 mm and a can body height of 168 mm, and the average plate thickness reduction rate of the can side wall portion with respect to the original plate thickness is 60%.

As a comparative product, the surface-treated aluminum plate was coated in the same manner as above without coating the polyester resin film, and then an epoxy / acrylic coating film having a thickness of 3 μm was formed and coated on the inner surface. A can body Y, which is a seamless aluminum can having a film, was produced. As the epoxy / acrylic paint, the paint described in Example 1 of International Publication No. 2010/013655 was used.

(Making a can lid)
A polyester / phenol-based paint or an epoxy / acrylic-based paint is applied to a JIS A5182H19 aluminum alloy coil having a plate thickness of 0.26 mm as a dry coating on the inner surface side, and then coil-coated so that the thickness is 8 μm, and then aluminum. The coating film was baked in a gas oven so that the peak temperature of the plate was 260 ° C. and the total heating time was 28 seconds to obtain a coated aluminum coil. Further, on the outer surface side of the aluminum plate, an epoxy / acrylic paint different from that on the inner surface side was formed so that the dry film thickness was 4 μm. As the polyester / phenol-based paint, the paint described in Example 8 of JP2013-249376A was used.
Using the painted aluminum coil, the depth from the center panel of the radius portion of the reinforced annular groove is 2.5 mm, and the radius of curvature of the radius portion is 0.50 mm in a shell (cover for attaching a tab for opening) molding machine. A 206-diameter shell was formed. Riveting, scoring from the outer surface side of the lid (residual score thickness 95 μm), and attachment of an opening tab were performed on this to prepare a can lid Z, which is a SOT can lid.

The can body X was filled with white wine and sealed with the can lid Z. Similarly, the can body Y was also filled with white wine and sealed with the can lid Z. After storing these packaged wines under a constant temperature condition of 23 ° C. for 6 months, the inner surface of the can and the inner surface of the lid were observed. Tables 1 and 2 show the pH, sulfur dioxide molecule content, and corrosion state of the filled white wine. Table 1 shows the results of the can made of the can body X and the can lid Z, and Table 2 shows the results of the can made of the can body Y and the can lid Z.
Further, FIG. 1 (a) shows a photograph of the inner surface of the can body X after 6 months have passed under the constant temperature condition of 23 ° C. filled with white wine L, and FIG. 1 (b) shows the can body Y. A photograph of the inner surface and a photograph of the inner surface of the can lid Z attached to the can body X are shown in FIG. 1 (c). FIG. 2A shows a photograph of the inner surface of the can body X after 6 months have passed under the constant temperature condition of 23 ° C. filled with white wine M, and FIG. 2B shows the inner surface of the can body Y. Each photo is shown. FIG. 3A shows a photograph of the rivet-processed portion of the can lid Z mounted on the can body X after 6 months have passed under the constant temperature condition of 23 ° C. filled and sealed with white wine N.

Claims

It consists of an aluminum can body having at least a polyester resin coating on the inner surface of the can and an aluminum can lid covering the opening of the aluminum can body, and has a pH of 3.0 to 4.0 and a sulfur dioxide molecule content of 1.9 mg /. An aluminum can for filling wine, which is characterized by filling wine of L or less.
The aluminum can for wine filling according to claim 1, wherein the sulfur dioxide molecule content is 0.4 to 1.9 mg / L.
The aluminum can for wine filling according to claim 1 or 2, wherein a coating film made of polyester / phenol-based paint is formed on at least the inner surface side of the aluminum can lid.
The aluminum can for wine filling according to any one of claims 1 to 3, wherein the thickness of the body of the polyester resin coating is in the range of 4 to 30 μm.
The aluminum can for wine filling according to claim 3, wherein the thickness of the coating film on the can lid is in the range of 6 to 20 μm.
The aluminum can for wine filling according to any one of claims 1 to 5, wherein the polyester resin coating is made of an ethylene terephthalate polyester resin.
The aluminum can for wine filling according to any one of claims 3 to 6, wherein the polyester / phenol-based paint is formed of a paint composition containing a polyester resin as a main agent and a resole-type phenol resin as a curing agent.
The aluminum can for wine filling according to any one of claims 1 to 7, wherein the can body is a seamless can.
The aluminum can for wine filling according to any one of claims 1 to 8, wherein the can lid is a stayion tab type easy open can lid.
The aluminum can for wine filling according to any one of claims 1 to 9 is filled and sealed with wine having a pH of 3.0 to 4.0 and a sulfur dioxide molecule content of 0.4 to 1.9 mg / L. Aluminum canned wine characterized by that.