JP5937337B2 - Manufacturing method of bottle-shaped can and bottle-shaped can - Google Patents

Description

  The present invention relates to a method for manufacturing a bottle-shaped can in which a can body, a shoulder portion, and a mouth and neck portion are integrally formed from a thin metal plate, and in particular, filling and sealing highly corrosive contents such as foaming wine. The present invention relates to a method for manufacturing a bottle-shaped can suitable for manufacturing and a bottle-shaped can manufactured by the manufacturing method.

  In recent years, the types of contents filled and sealed in bottle-shaped cans have also diversified. As soft drinks, various contents such as mineral water, sports drinks, Japanese tea, black tea, Chinese tea, coffee drinks, carbonated drinks, fruit / vegetable drinks, and the like are filled, sealed, and sold. As alcoholic beverages, for example, low alcoholic beverages such as beer, sour and cocktails are filled and sealed as contents and sold.

  By the way, among alcoholic beverages, particularly in the case of fruit fermented liquors such as wine, corrosive sulfites such as sodium sulfite are generally used as antioxidants. Therefore, when filling and sealing such a beverage in a bottle-shaped can, the protective film on the inner surface of the bottle-shaped can easily deteriorates due to sulfurous acid, and as a result, corrosion resistance cannot be maintained and the metal surface of the main body is corroded, Eventually, the contents may leak due to pitting. Therefore, it has been difficult to fill and seal bottles as contents of wine and the like in which an antioxidant containing sulfite is used unless the concentration of sulfite is lowered.

  In order to deal with such a problem, in Patent Document 1, the inner surface is coated with a paint having excellent workability before the can is processed, and then necking and flange processing or screw processing (including curling) is performed. Later, an aluminum bottle can that has been given corrosion resistance by applying a second layer of coating has been proposed. However, there are concerns about the effects of the organic solvent on the body and environmental pollution during and after painting, and it is expensive and economical because it is necessary to apply the coating twice before and after the threading process. is not. Therefore, there is a demand for an inner surface of the can body that is not subjected to inner surface coating.

  On the other hand, Patent Document 2 discloses a metal can in which a can body is formed from a resin-coated metal plate coated with a resin layer on at least the inner surface of the can through a drawing process and an ironing process. By adding calcium carbonate as a co-acid that reacts with sulfurous acid to the portion other than the uppermost layer in the resin film, sulfurous acid is prevented from permeating the resin layer of the protective coating and reaching the metal surface. A metal can for wine canning that can prevent the corrosion of the metal can due to the above is described.

  According to this, calcium carbonate as a co-acid agent reacts with sulfurous acid, and there is an effect of suppressing corrosion of the can due to sulfurous acid and deterioration of the flavor of wine. Therefore, according to the invention described in Patent Document 2, the corrosion of the can and the deterioration of the flavor of the wine can be prevented without reducing the concentration of sulfurous acid contained in the antioxidant of the wine, and the inner surface of the can Since the surface to be covered is covered with a resin film, the above-described organic solvent does not cause adverse effects such as an influence on the body and environmental pollution, and is also commercialized.

JP 2006-264734 A JP 2006-62688 A JP 2001-270596 A

  By the way, the bottle-type can is filled with the contents and the container mouth is covered with an aluminum cap, and then sealed by a capping method called roll-on capping. Specifically, as described in Patent Document 3, for example, a cap is put on the container mouth, and the top surface of the cap is subjected to a stoppering pressure so that the opening end of the container mouth is made of a resin of the cap. The liner is brought into close contact. Then, in this state, the screw forming roller is pressed against the cylindrical skirt portion peripheral surface of the cap to form a screw portion along the thread of the container mouth portion, and a skirt tightening roller (lower end) is formed on the cap skirt hem portion. The cap is attached to the container mouth portion.

  When filling and sealing wine that is more corrosive than normal wine, especially sparkling wine such as champagne and sparkling wine, using the roll-on capping method, No means has been found to solve the problem of corrosion.

This, for example, when mounting the caps for pilfer proof the container opening, since a pilfer proof band after opening the cap needs to be left in the container opening, an annular lower end of the skirt portion of the cap bead It is formed to be locked to the part . Therefore, the lower end portion against the lower end of the cap by a plurality of foot tightening Russia over La capping device when pushed into the annular bead portion, the annular bead portion to become deformed by the pressing, the inner surface of the annular bead portion In some cases, micro defects may occur in the coating. It is thought that this part is corroded by the influence of carbon dioxide and sulfurous acid.

  In this way, when filling and sealing bottle-shaped cans with highly corrosive sparkling wines such as champagne and sparkling wine, the corrosion of metal cans caused by carbon dioxide contained in sparkling wine In addition, there is an unsolved problem that the flavor of the wine is impaired due to this, and the application of a bottle-shaped can as a container for highly corrosive foaming wine is desired.

  The present invention has been made by paying attention to the above technical problem, and is a bottle-shaped can excellent in corrosion resistance and storage stability even when the content is highly corrosive foaming wine or the like. An object of the present invention is to provide a manufacturing method and a bottle-shaped can manufactured by the manufacturing method.

  In order to achieve the above object, that is, in order to prevent the promotion of metal corrosion by carbon dioxide contained in the contents such as effervescent wine in the bottle-shaped can, as a result of repeating various experiments, the contents are filled. Overcoming the above problems by locally heating and quenching the previous container mouth to make the inner coating amorphous and at least restore the elastic modulus and ductility of the inner protective coating on the container mouth I understood that I could do it. Therefore, as means for solving the above-mentioned problems, the invention of claim 1 is a coating in which a thermoplastic resin coating layer is formed on a surface corresponding to at least the inner surface side of a metal thin plate and a lubricant is applied. A cup forming process for forming a cup by punching a thin metal plate, a can body forming process for forming a bottomed cylindrical body having a further reduced diameter from the cup, and one end of the bottomed cylindrical body being compressed. The neck-and-neck part forming step for forming the shoulder part and the mouth-and-neck part, the opening end part at the tip of the mouth-and-neck part is formed in the curled part, and the screw part and the annular bead part are formed in the mouth-and-neck part. In the manufacturing method of a bottle-shaped can including a curling, screw, and bead forming step, the mouth and neck portion above the shoulder portion is connected to the mouth and neck portion with respect to the can body after the curling, screw, and bead forming step. At least on the inner surface side of the can Heating the resin coating layer to a temperature equal to or higher than its melting point and immediately quenching to provide an amorphization step for amorphizing the thermoplastic resin coating layer on at least the inner surface of the can and neck. It is the manufacturing method of the bottle-shaped can characterized.

  The invention of claim 2 is the invention of claim 1, wherein the mouth-and-neck portion forming step reduces the diameter of the bottom of the can including the vicinity of the bottom of the bottomed cylindrical body so that the shoulder portion and the mouth-and-neck portion A step of forming the top dome, in which the amorphization step is performed by opening the mouth / neck portion which is not opened and winding a bottom lid on a lower end portion of the trunk portion opposite to the mouth / neck portion. A method for producing a bottle-shaped can, comprising a step of amorphizing the thermoplastic resin coating layer on at least the inner surface of the can neck with respect to a can body with a bottom lid.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the amorphization step is heated with an induction heating step of passing the inside of the induction heating device while rotating the can body about the can axis. And a cooling step in which the mouth and neck of the can body is immediately immersed in a cooling water bath and rapidly cooled.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the amorphization step is immediately immersed in the cooling water tank with the mouth-and-neck portion facing downward to be rapidly cooled, and the cooled can body On the other hand, it is a manufacturing method of the bottle-type can characterized by including the draining process which blows off the water droplet adhering to the said mouth-and-neck part by air in the state which faced the said mouth-and-neck part downward.

  The invention according to claim 5 is the invention according to claim 3 or 4, wherein the amorphization step conveys the can body with the mouth and neck portion facing downward, and the can axis center of the mouth and neck portion is placed on the water surface. The mouth and neck part is immersed in the cooling water tank in a state of being inclined with respect to the cooling water tank and rapidly cooled, and after the mouth and neck part is rapidly cooled, reverse to the case where the mouth and neck part is immersed in the cooling water tank. It is a manufacturing method of the bottle-shaped can characterized by including the cooling process which makes it incline and takes out from the said cooling water tank.

  The invention according to claim 6 is the invention according to any one of claims 3 to 5, wherein the amorphization step is configured such that the cooling water in the cooling water tank is moved at a speed substantially equal to the moving speed of the can body. It is a manufacturing method of the bottle-type can characterized by including the cooling process which convects the same direction as the moving direction in the said cooling water tank of a can body.

The invention of claim 7 is a bottle-type can with the least can inner side resin-coated metal thin plates thermoplastic resin film layer is formed on the corresponding surface to the material of the metal sheet, neck The crystallinity (Cn) of the thermoplastic resin of the thermoplastic resin coating layer on the inner surface side satisfies the following formula (1), and the thermoplastic resin in the thermoplastic resin coating layer on the inner surface of the mouth and neck portion crystallinity and (Cn), bottle-shaped can which crystallinity of the thermoplastic resin of the can body the central portion (Cw) and is characterized by satisfying the following formula (2).
Cn <1 (1)
Cn / Cw <1 (2)
However, Cn infrared absorption intensity was measured by IR analysis (reflection infrared spectroscopy), Cn = (peak height 1340 cm ^-1) / (the peak of 1578 cm ^-1 height). Cw is IR analysis infrared absorption intensity was measured at (reflection infrared spectroscopy), Cw = (peak height 1340 cm ^-1) / (the peak of 1578 cm ^-1 height).

The invention of claim 8 is the invention of claim 7, bottle-shaped, wherein the pre Kinetsu thermoplastic resins of the thermoplastic resin coating layer on the inner surface side of the mouth and neck are amorphous It is a can.

According to the bottle-shaped can manufacturing method of the present invention and the bottle-shaped can manufactured by the manufacturing method, at least the mouth-and-neck portion is locally heated with respect to the container mouth portion before filling the contents, thereby After making the coating resin layer on the inner surface of the can part non-oriented, the coating resin on the inner surface of the can generated at the time of molding the container mouth is made non-oriented amorphous by immediately cooling with, for example, pure water. be able to. As a result, micro defects of the inner surface thermoplastic resin layer generated when molding the neck and neck can be repaired, and the elastic modulus and ductility can be improved.耐衝impulsive force of the inner surface coating of sites distortion contact occurs (such annular bead portion) can be improved. Therefore, it is possible to minimize the damage of the thermoplastic resin layer on the inner surface of the annular bead, and it is excellent in corrosion resistance against foaming wine that is more corrosive than ordinary wine, and a thin bottle type can Can be manufactured. Therefore, it is possible to apply the bottle-type can to the highly corrosive foaming wine, and it is possible to expand the target range of the contents filled in the bottle-type can.

  In addition, in the amorphization process for the can body after the curl, screw, and bead forming process, only the mouth and neck portion above the shoulder portion of the can body is heated, so that the can body can withstand the capping pressure during capping. While maintaining the bending strength, the thermoplastic resin coating layer on at least the inner surface side of the mouth and neck can be amorphized. For this reason, filling and winding can be carried out without significant changes in the existing capping device, which is economical.

  Moreover, if it is the amorphization process with respect to the can after the bottom cover winding process, the generation | occurrence | production of the odor by heating the sealing rubber | gum of a bottom cover can be prevented.

It is a side view which shows an example of the bottle-type can made into object by this invention. It is a schematic diagram which shows the manufacturing process of the bottle-shaped can in the manufacturing method of this invention. It is an expanded sectional view which shows the detail of the mouth neck part of the bottle type can shown in FIG. It is a schematic diagram which shows the deformation | transformation state of the annular bead part in the roll-on shaping | molding (capping) in the manufacturing method of this invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[Bottle type cans]
FIG. 1 shows an example of a bottle-shaped can manufactured by the method of the present invention. The bottle-shaped can 1 has a dome shape whose longitudinal section is an arc shape upward from a cylindrical body 2 having a large diameter. A small-diameter cylindrical mouth-and-neck portion 4 is integrally formed through the shoulder portion 3, and the lower end opening portion of the trunk portion 2 is sealed by tight fastening of the bottom lid 5. A desired print design (characters, decorative patterns, etc.) is provided on the outer surface of the body part 2 so that a large part of the body part 2 including the shoulder part 3 shown by hatching in FIG. It has been subjected.

  FIG. 2 schematically shows a process for manufacturing the bottle-type can 1 with a bottom lid shown in FIG. In the method of this embodiment, first, cup molding is performed using a coated metal thin plate (laminated plate) in which a thermoplastic film layer in an amorphous state is formed on both surfaces of a metal thin plate and a lubricant is applied. In the process, the blank obtained by punching the coated thin metal sheet into a disk shape is formed into a cup shape by drawing, and at least one redrawing and ironing process is performed on the cup in the next can body forming process. This is performed to form a cylindrical can with a bottom having a small diameter and a thin wall.

  Next, in the trimming step, the opening end side of the can is trimmed to align the can to a predetermined length. Then, it is sent out for the same printing and painting process as in the case of the conventional two-piece can, and the desired design (characters, decorative patterns, etc.) is printed on the cylindrical body 2 in the printing and painting process. A top coat is applied from above. Thereafter, the printing ink layer and the top coat layer are sufficiently baked and dried in the drying step.

  For the bottomed cylindrical can that has been printed (and top-coated) on the body 2 as described above, in the mouth-and-neck portion forming step or the top dome forming step, The can bottom corner portion (the bottom portion and the body portion 2 in the vicinity of the bottom portion) is preliminarily molded into a shoulder curved surface having an arcuate cross section in a state in which the printed portion applied to the body portion 2 is included. When the drawing process is performed a plurality of times on the bottom side, the shoulder portion 3 and the mouth-and-neck portion 4 with the tip not opened are formed.

  Next, the can is heated in a known heating means, for example, a heating furnace such as a heating oven, so that at least the adhesion of the thermoplastic resin layer on the inner surface side of the can to the metal becomes strong. Then, in the curl, screw, and bead forming process, first, the mouth and neck portion 4 is opened by trimming the front end closing portion of the unopened mouth and neck portion 4, and then, as shown in the partial sectional view of FIG. The opening end portion 11 is formed into an annular curled portion 12 by external winding, and a screw portion 13 for screwing the cap is formed on the cylindrical peripheral wall of the mouth-and-neck portion 4. At the same time, the annular bead portions 14 and 15 are formed below the screw forming portion.

In other words, neck 4 with that uneven annular bead portions 14, 15 caries Chi annular bicycloalkyl over de portion 14 formed on the neck 4 is convex outwardly in the radial direction, under the the portion of the side, annular bi over de portion 15 recessed radially inwardly is formed. Accordingly, the inclined surface 14a which is the boundary between the annular bi over de unit 15 is configured to pilfer proof band of the cap to be described later is secured is engaged.

  In the neck and flange forming step, neck-in processing and flange processing are sequentially performed on the lower end opening end of the body portion 2 on the side opposite to the mouth-and-neck portion 4, and then in the bottom lid winding step, By means of a seamer (can lid tightening machine) (not shown), the bottom cover 5 which is a separate member made of a thin metal plate is integrated with the flange portion formed at the lower end opening of the body portion 2 by a double tightening method. It is fixed.

Next, in the bottle-type can 1 of the present invention, as described above, in the mouth-and-neck portion 4 of the can body with the bottom lid that has undergone the curl, screw, and bead molding process, the thermoplastic resin layer is again subjected to molding distortion. If roll-on molding is attempted in the capping process, the inner surface coating layer of the mouth and neck portion 4 is likely to be damaged. In particular, as shown in FIG. 4, a capping apparatus in the hem clamping b over La 21 abuts against the outer periphery of the annular bead portion 15 of the hem clamping Russia impact force instantaneously annular bead portion 15 of the over La 21 acts on hem tightening Russia over La 21 is more rotated by cap skirt fastening molding is carried out while further deforming the annular bead portion 15 of the thin inwardly. Forming a result, a plurality of skirt clamping Russia over La 21 (typically, from 2 3) the skirt fastening is done, for example, a thin resin-coated metal sheet than the thickness of 0.30mm at rationalization of material if it is, in particular, the skirt fastening Russia over La 21 by the shock impulsive force and subsequent Installing pressing force in contact with the annular bead portion 15, the thickness of thin annular bead portion 15 is elliptical or rice ball shape Rolling while being deformed, the cross-sectional shape of the annular bead portion 15 may remain deformed, or the diameter of the annular bead portion 15 may be reduced by about 0.1 mm to 0.4 mm. Therefore, a compressive stress or a tensile stress acts on the thermoplastic resin layer (or adhesive layer) on the inner surface side of the annular bead portion 15 in combination, and the resin layer is locally thinned and weakened, and micro defects are generated. easily (defects such micro is not from the yarn content such after the contents are capped and by storing certain bottle type cans filled-sealed). Thus, the bottle-shaped can 1 defects Mi black thermoplastic resin layer of the inner surface is caused in the annular bead portion 15, for example, mineral water, sports drinks, tea beverages, coffee beverages, carbonated drinks, fruit and vegetables When soft drinks such as beverages and alcoholic beverages such as beer and cocktails are filled and sealed as contents, there was no particular problem with respect to corrosion. However, when foaming wine such as champagne or sparkling wine, which is more corrosive than ordinary wine, is filled and sealed in the bottle-shaped can 1 as the contents, the metal of the can corrodes from the above-mentioned micro defects. And the problem of losing the flavor of sparkling wine has not yet been solved.

Typically, the wine, an appropriate amount of sulfite salt is added during the fermentation, also the amount used of the sulfite salt is defined to be used so as not to remain wine 1kg in 350 mg (350 ppm) or by the Food Sanitation Law and that although, sulfite metal corrosivity is extremely strong, easily corrode metal cans. Therefore, the protective coating on the inner surface of the can is carbonized so that it does not corrode the can metal during storage, and does not deteriorate the flavor by generating hydrogen sulfide due to the reaction between the sulfurous acid and the can metal. It is known to add calcium to collect sulfurous acid.

  Even if the above-mentioned micro defects are formed on this protective film, sulfite gas is contained by calcium carbonate contained in the protective film (thermoplastic resin layer or adhesive layer) when storing non-foamed wine not containing carbonic acid. Is collected and does not lead to corrosion of the metal surface. However, when a highly corrosive, effervescent wine is stored, carbon dioxide is generated in addition to sulfurous acid gas, so that the carbon dioxide penetrates into the protective coating from the micro defects and is added to the protective coating. It causes a reaction with the calcium carbonate that has been produced, and the function of collecting the sulfurous acid gas of calcium carbonate (sulfurous acid collecting power) is reduced or its function is slowed down. As a result, it is thought that the combined factors of sulfurous acid gas and carbon dioxide gas further corrode the metal of the can, and hydrogen sulfide is generated by the reaction between the sulfurous acid gas and the metal of the can to deteriorate the flavor. Not in.

  Therefore, in the present invention, a bottle that can be applied to highly corrosive contents such as effervescent wine while maintaining the function of collecting sulfurous acid without adding an acid scavenger such as calcium carbonate more than necessary. In order to provide the mold can 1, the thermoplastic resin layer, which is the inner surface coating of the annular bead portions 14, 15, is locally heated in the amorphous process on the neck 4 before filling the contents. A rapid heat treatment is performed so that the crystallinity of the inner surface coating resin of the annular bead portions 14 and 15 is made amorphous so that the crystallinity of the inner surface coating resin of the body portion 2 is lower. ing. Thereby, the plastic deformation associated with the curl, screw, and bead molding, particularly the soundness of the coating of the annular bead portions 14 and 15, is restored, and the bottle can 1 is completed as shown in FIG.

  The material configuration of the bottle-shaped can 1 of the present embodiment as described above will be described. The metal plate applied to the bottle-shaped can 1 of the present invention is not particularly limited and is usually used as a material for cans. Is used. For example, a black plate, a phosphoric acid-treated steel plate, a chromic acid-treated steel plate, an electrolytic chromic acid-treated steel plate, aluminum, chromed aluminum, an aluminum alloy plate, and the like are suitable. When an aluminum alloy plate is used, a 3004 series aluminum alloy is preferably used. The thickness of the aluminum alloy plate is 0.20 to 0.32 mm. When the plate thickness is less than 0.20 mm, the strength and the buckling strength against the capping pressure during capping are not sufficient. On the other hand, if the plate thickness exceeds 0.32 mm, the buckling strength is sufficiently ensured, but the quality is practically excessive and not economical.

  Next, the thermoplastic resin used as the protective film applied to this invention is demonstrated. In the present invention, a thermoplastic resin film such as polyester resin or polypropylene resin is used as a protective coating on the inner surface of the can body. Examples of the polyester resin include a homopolymer such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene isophthalate, or a copolymer that is a mixed resin of polyethylene terephthalate and polyethylene isophthalate, and such homopolymers or copolymers. A blend resin etc. are mentioned, It can apply by a single layer or a multilayer.

  The thickness of the resin film of this invention is suitably 10 to 50 μm. The thickness of the resin film laminated on the surface corresponding to the inner surface of the can is limited from the point of corrosion resistance after roll-on capping, and when less than 10 μm is filled with highly corrosive contents, It is difficult to ensure corrosion resistance. On the other hand, if it exceeds 50 μm, corrosion resistance is sufficiently secured even for highly corrosive contents, but it is substantially excessive quality and is not economical. Therefore, the thickness of the resin film is 10 to 50 [mu] m, and 12 to 40 [mu] m is particularly preferable in terms of quality and economy.

Moreover, additives, such as antioxidant, a heat stabilizer, a plasticizer, and a lubricant, can be disperse | distributed and mix | blended with a resin layer as needed. And, in this invention, since the wine sulfite salt is added is filled, sealed as contents, calcium carbonate which acts as a co-oxidizer that reacts with sulfite contained in the wine, the resin film Of these, it is added to the resin other than the surface layer avoiding contact with the processing jig. As a result, sulfurous acid in the wine permeates the protective coating on the inner surface of the can and corrodes the metal of the can, or reacts with the metal to generate hydrogen sulfide and deteriorates the flavor of the wine. It can be effectively suppressed. About the addition amount of this calcium carbonate, it sets suitably according to the amount of sulfurous acid in wine.

  As a method of laminating the thermoplastic resin film on the metal thin plate, in addition to the case where the thermoplastic resin film formed in advance is directly heat-bonded to the metal surface of the metal thin plate, the metal pre-heated from the thermoplastic resin melted from the T die is used. When extruding onto a thin plate and directly adhering it, a metal surface of a thin metal plate is formed via an adhesive primer layer, a curable adhesive layer, or a thermoplastic resin layer with good thermal adhesiveness. It is possible to adopt a method of thermally bonding to the surface.

A cap (not shown) applied to the bottle-shaped can 1 of the present invention is a metal bottomed cylindrical body having a top plate portion and a skirt portion. Therefore, after the contents are filled from the container opening on the opening side of the bottle-type can 1, the cap is put on and the roll top is applied in a state in which the cap top plate is applied with a capping device by a conventionally known capping device. Molded (capped). By threading roller are female thread formed on the cylindrical portion definitive the skirt 22 of the cap is further sealed more skirt skirt hem tightening low la 21 (opening side end) 23 is skirt tightened.

  The material of the cap is not particularly limited, but generally JlS A1100 alloy or A3105 alloy having excellent formability is used. Further, a resin such as epoxy-phenol is applied to the inner surface.

A sealing resin liner member is integrally provided on the inner surface side of the top plate portion of the cap. Such a cap is generally configured so that it can be resealed after being opened once. For this reason, a pilfer loop cap that can be easily identified once opened is used. . This cap is provided with a pilfer proof band on the skirt portion 22 via a bridge, and has a function of preventing mischief because the bridge remains at the container mouth after the bridge is broken when the cap is opened.

As described above, after the bottle-shaped can 1 is filled with the contents, when the cap is attached to the mouth / neck portion 4, the cap / top portion of the cap is put on the mouth / neck portion 4 from above. Blowing pressure is applied. Then, in a state where the plugging pressure is applied, a female screw portion corresponding to the male screw portion 13 of the mouth / neck portion 4 is formed in the cylindrical portion of the skirt portion 22 of the cap by roll-on molding using a screw molding roller. At the same time , as shown in FIG. 4, the skirt 23 of the cap skirt portion 22 is hem-clamped by the hem-clamping roller 21 so as to engage with the inclined surface 14 a at the lower end of the convex bead portion 14. The mold can 1 is manufactured. When the cap is put on the neck 4 of the bottle-type can 1 and roll-on molded in this way, the annular bead portions 14, 15, particularly the concave bead portion 15 and the inclined surface 14 a are caused by the side load of the hem fastening roller 21. The cross section is easily deformed and reduced in diameter into an elliptical shape or a rice ball shape. In the present invention, making the resin film provided on the inner surface of the can of the annular bead portions 14 and 15 of the mouth and neck portion 4 is amorphizing is a capping pressure and a bottom tightening low during such roll-on capping. Since it is closely related to the impact force and side load of the rubber 21, it will be further described in detail.

  The amorphization process of the present invention is a process for amorphizing the curled, screwed, and beaded neck 4, that is, a heat treatment for heating the entire can body that is applied in the previous process. Unlike the above, it is an amorphization process mainly for the mouth-and-neck portion 4 and is configured to heat a local portion. Thereby, at least the thermoplastic resin layers on the inner surfaces of the annular bead portions 14 and 15 are locally heated (for example, high-frequency induction heating) to be amorphized. Therefore, as described above, when the cap is placed on the neck 4 of the bottle-type can 1 and roll-on molded, the cross-section of the annular bead portions 14 and 15 is elliptical due to the dent and side load due to the impact force of the hem fastening roller 21. Even when the shape is deformed and reduced in diameter or in the shape of a rice ball, the thermoplastic resin layer on the inner surfaces of the annular bead portions 14 and 15 is made amorphous so that the thermoplastic resin layer It is possible to follow the roll-on molding without difficulty. As a heating device for the amorphization treatment, a known heating means such as an electric furnace, a gas oven, an infrared heating device, etc. can be used as appropriate in addition to a high frequency induction heating device.

  In other words, as a result of repeating various experiments to prevent the promotion of metal corrosion by carbon dioxide and sulfurous acid, the container mouth was locally heated and rapidly cooled with respect to the container mouth before filling the contents, It has been found that it is effective to make the inner surface coating of the container mouth part amorphous. In addition, a shield is attached to the shoulder portion 3 from the shoulder portion 3 to the body portion 2 of the bottle-type can 1 in order to prevent the influence of softening of the metal and to minimize the heat history of the inner surface coating resin layer. For example, it is preferable to exclude from the heat treatment or to minimize the heat effect of the heat treatment.

  As a result, foamed wine having a high acidity (low pH) and corrosive than ordinary wine is filled and sealed as a content, and the air layer (mainly sulfurous acid gas in the head space of the bottle-type can 1 is used. Even in the case where the contained carbon dioxide gas) and the inner surface of the container mouth portion are in contact with each other, the above roll-on molding can be appropriately performed.

  Next, the amorphous process will be described in detail below. In this step, first, the inner surface protective coatings of the annular bead portions 14 and 15 are subjected to high-frequency induction heating until a temperature range equal to or higher than the melting point of the resin, so that at least the thermoplastic resin on the inner surfaces of the annular bead portions 14 and 15 is melted. It is done. Then, after the thermoplastic resin is heated and melted to become non-oriented, the mouth and neck portion 4 of the body portion 2 is turned downward and immersed in a cooling water tank filled with pure water having a temperature equal to or lower than the cold crystallization temperature of the resin. Is done. As a result, the mouth and neck portion 4 is rapidly cooled, and at least the thermoplastic resin layer on the inner surfaces of the annular bead portions 14 and 15 is made amorphous. After that, air is blown to the container mouth portion to drain the water. The degree of amorphization of the neck 4 of the bottle-type can 1 obtained through this amorphization step is determined by lR analysis (reflection infrared spectroscopy) as the crystallinity of the inner film of the can. taking measurement.

As a measurement method of IR analysis, the inner surface film is isolated by immersing the annular beads 14 and 15 in an 8% aqueous hydrochloric acid solution to dissolve the base material, and the surface of the film (content side) by the ATR method (attenuated total reflection method). ), And the degree of crystallinity was determined from an infrared absorption peak at 1340 cm ⁻¹ and an infrared absorption peak at 1578 cm ⁻¹ derived from polyethylene terephthalate obtained therefrom.

Then, the crystallinity (Cn) of the inner surface coating resin of the annular bead portions 14 and 15 by IR analysis satisfies the following formula (1), that is, an amorphous state where the crystallinity (Cn) is less than 1. It is important to become.
Cn <1 (1)
However, Cn infrared absorption intensity was measured by IR analysis (reflection infrared spectroscopy), Cn = (peak height 1340 cm ^-1) / (the peak of 1578 cm ^-1 height).

Furthermore, in the state of the bottle-type can 1 after molding, the crystallinity of the inner surface resin of the mouth neck part 4 (Cn) is smaller than the inner surface side of the crystallinity of the can body 2 (Cw) state, by other words satisfies the following formula (2) (number decreases) is subjected to heat treatment to amorphous the Kuchi頸unit 4 as was maintained buckling resistance column strength of the can body against stoppered pressure upon capping It remains, it is possible to improve the corrosion resistance of the inner surface coating even without less of the mouth neck part 4 of the can body after capping. Also, if it meets amorphized formula mouth neck portion 4, leaving the molecular orientation of the inner surface film formed during forming the shape of the can body 2 (2), further dent of the can body 2 There is also an advantage that sex is maintained.
Cn / Cw <1 (2)
However, Cw infrared absorption intensity was measured by IR analysis (reflection infrared spectroscopy), Cw = (peak height 1340 cm ^-1) / (the peak of 1578 cm ^-1 height).

  The reason why the temperature of the cooling water tank is in the temperature range of 50 to 70 ° C. is that, even if pure water is circulated in the cooling water tank, the risk of breeding microorganisms that may threaten food safety This is to remove sex. That is, for example, most causative bacteria causing food poisoning grow most vigorously in the temperature range of 10 to 37 ° C., so the lower limit temperature of the cooling water tank is set to 50 ° C. In addition, since bacteria that can grow at a high temperature of 85 ° C. or higher have recently been discovered, the upper limit temperature of the cooling water tank is set to 70 ° C. to prevent bacteria from breeding in the cooling water tank.

  In addition, when the mouth and neck portion 4 is immersed in a cooling water bath and rapidly cooled, the mouth and neck portion 4 is inclined with respect to the surface of the water, thereby allowing the cooling water to easily enter the mouth and neck portion 4. Can do. Then, after the mouth and neck portion 4 is immersed in the cooling water tank and rapidly cooled, when the can is pulled out of the cooling water tank, the cooling water in the mouth and neck part 4 is drained at an inclination angle opposite to that when the can is landed. By separating the water from the cooling water tank, it is possible to prevent the influence of the air in the can, and to smoothly enter and exit the cooling water into the mouth / neck portion 4.

  Further, the cooling water whose temperature is adjusted as described above is circulated and supplied into the cooling water tank. At that time, as a method of supplying the cooling water, with respect to the moving direction of the can body in the cooling water tank, at the same speed as the moving speed of the can body (the same speed including almost the same speed), And it is supplied so that cooling water may flow in the same direction as the moving direction of the can. By doing so, it is possible to promptly flow cooling water into the mouth / neck portion 4. Moreover, at the time of water separation, water can be drained from the mouth-and-neck part 4 and the resistance of the water can be reduced without causing the cooling water tank liquid surface to wave. Therefore, even if the can body is a lightweight can, the can body can be stably moved while being immersed in the cooling water tank without causing the mouth-and-neck portion 4 to fluctuate.

Also, after the curl, screw, and bead forming process, the lower end of the body part 2 is necked and flanged, and after the bottom cover winding process, the body part is not deformed even if the body part 2 is thinned. 2 can be firmly held from both sides, and the high-frequency induction heating can be performed on the annular bead portions 14 and 15 of the mouth-and-neck portion 4 while being stably rotated about the can axis. Therefore, the annular bead portions 14 and 15 can be heated uniformly.

  Furthermore, when the mouth and neck portion 4 is immersed in a cooling water bath and rapidly cooled, the mouth and neck portion 4 is inclined with respect to the water surface and allowed to land on the water, so that the air in the can can be smoothly discharged into the mouth and neck portion 4. Cooling water can be allowed to intrude into the water, and thus rapid cooling can be performed. In addition, after cooling, when the mouth and neck part 4 is lifted from the cooling water tank, water is removed from the cooling water tank at an inclination angle opposite to that at the time of landing, thereby preventing pulsation from the inside of the mouth and neck part 4 and smoothly supplying cooling water. It can be drained. Therefore, the draining operation can be easily performed.

  Furthermore, when the neck portion 4 of the body 2 is rapidly cooled downward, the cooling water in the cooling water tank is almost the same as the moving speed of the can body with respect to the moving direction of the can body in the cooling water tank. By flowing in the same direction as the direction of movement of the can body at high speed, the cooling water can be quickly flowed into the mouth-and-neck portion 4, and when the water is removed, the surface of the cooling water tank is not waved. The resistance of the cooling water can be lowered by draining the cooling water from the portion 4. Therefore, even if the can body is a lightweight can, the can body can be stably moved while being immersed in the cooling water tank without causing the mouth-and-neck portion 4 to fluctuate.

(Concrete example)
Resin-coated metal sheet thickness 0.285 mm, a material A3004H19, AB strength 270N / against mm ² of the aluminum alloy plate, polybutylene terephthalate resin (PBT) and polyethylene terephthalate resin (PET) and mixed resin (PBT: PET = A coated metal thin plate is used in which a film of 60:40) is laminated to have a thickness of 20 μm on the inner surface side of the can and a thickness of 20 μm on the outer surface side of the can. Further, the film on the inner surface side of the can is laminated using an epoxy resin containing calcium carbonate as an adhesive.

Manufacture of bottle-shaped cans In the cup forming process, the polyester resin-coated metal plate is punched into a circular plate and drawn into a cup shape having a height of 42 mm and an outer diameter of 95 mm. The side wall of the cup-shaped member is subjected to drawing and ironing (total ironing ratio: about 40%), and then the opening end side is trimmed to a predetermined length and the one end side is opened to a can body diameter of 59 mm. A can-shaped member having a bottomed cylindrical shape and a can height of 142 mm is formed. Thereafter, the bottom plate side of the can-like member is drawn as a top dome (the upper end is closed), and an intermediate body of the bottle-type can 1 having a can height of 174 mm is formed.

Next, when the lubricant is removed from the intermediate, the intermediate resin film is amorphized. Thereafter, Carl with apertures end side of Emotion member is trimmed again, cut away closed portion of neck 4 is caused to open, the open end 11 of the neck 4 is outside wound annular part 1 2 is made form. Then, a screw forming portion having a male screw portion 13 for screwing with a female screw portion of the cap with respect to the cylindrical peripheral wall of the mouth and neck portion 4 continuing downward from the outer curled portion 12, and below the screw forming portion. Positioned annular bead portions 14 and 15 are respectively formed.

  Further, the outer wall 28 mm of the convex annular bead portion 14 and the outer diameter 25.9 mm of the concave annular bead portion 15 are formed on the circumferential wall (outer diameter 28 mm) drawn as the top dome, and the convex bead is formed. An inclined surface 14 a of 45 ° is formed at the connection portion from the portion 14 to the concave bead portion 15.

  In the container mouth portion of the bottle-type can 1 thus obtained, an 8-thread / inch thread portion 13 is formed on the circumferential wall.

  Then, with respect to the can-like member in which the curled portion 12, the screw portion 13, the annular bead portions 14, 15 and the like are formed in the mouth and neck portion 4, the lower end opening portion of the body portion 2 on the opposite side to the mouth and neck portion 4 is provided. The bottom cover 5, which is made of a thin metal plate material that has been subjected to neck-in processing and has a thermoplastic resin film attached to both sides, is doubled at the lower end opening edge of the necked-in body 2. It is fixed integrally by a winding method.

  Further, while the can body is being rotated, the can body is passed through a tunnel-like high-frequency induction heating device disposed on both sides of the mouth and neck portion 4 while being rotated in a short time, and the temperature of the can body is 265 ° C to 300 ° C. The temperature is raised to the range.

The high-frequency induction heating apparatus, an induction heating coil is arranged parallel to the sides of the conveyor, is arranged so as in particular to heat around the mouth neck part 4 of the can body. And although the heating region depending on the conveyor speed, the yet full range of can temperature 265 ° C. to 300 ° C. in particular an annular bead portion 14, 15 a few seconds of 30 m / min even when conveyed at a speed higher than the mouth neck part 4 as it can be heated in the circumferential uniformity, heat resistance of the grip belt conveyor for conveying by rotating the can body in the can axis center across the sides of the can body 2 to the can body 4 rotates or is arranged. Also, a radiation thermometer is provided at the outlet of the high-frequency induction heating device, and the system is electrically configured so that the temperature of the can coming out of the heating region can be measured to control the output of the high-frequency transmitter (see FIG. Not shown). This makes it possible to reliably raise the can temperature to a desired temperature even if the conveyor speed fluctuates. In addition, when conveying a can body with a turret, this high frequency induction heating apparatus is arrange | positioned in circular arc shape along a conveyance path.

Thereafter, the mouth / neck portion 4 having a temperature of 200 ° C. or higher is immersed in a cooling water bath having a water temperature of 60 ° C. ± 10 ° C. in a short time (within 3 seconds in this example) from the outlet of the high-frequency induction heating device. By this way neck 4 prior to filling the contents in is heated and rapidly cooled, the thermoplastic resin layer of the inner surface of at least the annular bead portion 14, 15 is amorphous, the mouth neck part 4 Micro defects in the inner resin layer of the can, particularly the thermoplastic resin layer on the inner surfaces of the annular bead portions 14 and 15, which are generated when the resin is molded, are repaired. Then, the coating resin layer on the inner surface side of the mouth / neck portion 4 is drained after the amorphization treatment , the plate thickness at the concave bead portion 15 is 0.285 to 0.36 mm, and the hardness is Hv 84 to 88 (treatment). The bottle type can 1 having a Hv of 92 to 96), a can height of 162 mm, and a taste amount of 300 ml was obtained. It was also confirmed that the amorphized state of the inner surface coating layer of the neck portion 4 was at a level higher than the amorphized state of the inner surface coating layer of the body portion 2.

As a result of the crystallinity of the thermoplastic resin of the inner surface side of the mouth neck part 4 (Cn) as measured in this embodiment, it was Cn = 0.25. Further, a mixed resin of polybutylene terephthalate resin (PBT) and polyethylene terephthalate resin (PET), was prepared similarly to the embodiment in place of the polyethylene terephthalate resin, a thermoplastic resin of the inner surface side of the mouth neck part 4 non Akirashitsuka a result, a Cn = 0.75, both the crystallinity of the thermoplastic resin of the inner surface side of the mouth neck part 4 (Cn) it was confirmed that less than 1.

The bottle-shaped can 1 is filled with a corrosion-promoting liquid for sparkling wine (composition: carbonated water 270 g, ethanol 30 g, citric acid 1.5 g, potassium pyrosulfite 60 mg), and the clogging pressure is 80 kgf. the door Torque of tightening low-La 21 3. Perform tight sealing seam set to 0N m, in an erected state, at room temperature 38 ° C., were performed 1.3 months storage. After the storage, as a result of observing the surface of the mouth and neck part 4 (curl part 12, screw part 13, annular bead parts 14 and 15), it was confirmed that there was no abnormality.

As a comparative example, the crystallinity of the thermoplastic resin of the inner surface side of the untreated cans (mouth neck part 4 which was not subjected to the amorphization treatment of the mouth neck part 4 (Cn) is 1 or more cans, for example, Cn is for about 1.5 cans), was charged with the above and similar contents, results were evaluated in the same manner the bottle-shaped can 1 was tightened, even weaken the side load of the foot clamping row La 21, annular bead portion Film damage (micro defects) on the inner surfaces of 14 and 15 was not alleviated, and corrosion was observed. Note that shall not hem tightening molded by foot tightening row La 21, the corrosion was not almost observed.

  The present invention is not limited to the above-described embodiment. For example, the metal thin plate as shown in the embodiment is not limited to an aluminum alloy plate, but various metals used for can manufacturing. A surface-treated metal plate such as a surface-treated steel plate subjected to surface treatment such as plating or chemical conversion treatment, for example, a TFS plate can also be used. The type of metal plate to be used or the surface-treated metal plate to be used may be determined in consideration of the corrosion resistance of the metal thin plate against the contents of the can, and it goes without saying that the design can be changed as appropriate.

  In the above embodiment, a specific example using a blend resin of PET and PBT as a coating resin has been described. However, the present invention is not limited to this thermoplastic resin, for example, a copolymer such as copolymerized PET, Even in the case of a mixed resin of homopolymers or copolymers, it can be applied.

In the present embodiment, in the state after the molding of the mouth neck part 4 of the bottle-shaped can 1, and so as to satisfy the above relational expression (1) by amorphous the mouth neck part 4 However, it may not be necessary to perform the amorphization treatment. For example, the selection of the resin composition, co by the addition of the polymerization component or selected to slow the crystallization rate, or the cooling of the heating and cooling step after forming the shape of Kuchi頸portion 4 to force the low-temperature cooling air by or adopting the cooling method of blowing, presumed to satisfy the relational expression crystallinity of the inner surface coating resin described above of the mouth neck part 4 (1), it is possible to solve the technical problem of the present invention it can.

  In addition, the amorphization process of the present invention is performed after the bottom cover tightening process, but is not limited thereto, and is applied to the can body after the curl, screw, and bead forming before the bottom cover tightening process. Is also possible. However, since the can body rigidity of the can increases after the bottom lid tightening process in which the bottom cover 5 is wound around the body portion 2, the body portion 2 may be sandwiched between the conveyor belts from both sides. Deformation can be prevented, and the neck and neck portion 4 can be uniformly induction-heated while rotating the can body by running the conveying belts on both sides in opposite directions. Therefore, it is desirable that the amorphization process of the present invention is performed after the bottom lid winding process from the viewpoint of uniformity, high-speed transportability, and the like.

Further, if the can body has a buckling strength against the capping pressure of the capping, the entire neck portion 4, that is, the annular bead portions 14 and 15, except for the shoulder portion 3, the screw portion 13 and the curl portion. It may be heated up to the part 12. However, damage in the thermoplastic resin layer of the annular bead portion 14, 15 than the neck 4 which receives the time of roll molding, most large among the sites distal skirt fastening row La 21 circulates while abutting directly. Therefore, considering the thinning of the body 2 and the embrittlement of the thermoplastic resin layer due to the thermal history, only the annular bead portions 14 and 15 and the adjacent portions thereof are locally subjected to high-frequency induction heating so that the inner surface thermoplastic resin layer is not coated. It is desirable to crystallize.

  In addition, in the above embodiment, the rapid cooling of the mouth and neck portion 4 according to the present invention shows an example in which the can body is immersed in the cooling water tank. However, the invention is not limited to this, and for example, cooling water spraying or air cooling is used. A cooling method can also be applied.

Further, in the embodiment of the invention, an example of a bottle-shaped can 1 having a bottom lid seamed step tightening up the bottom lid 5 to the lower end of the body portion 2 is not limited to this, the bottom cover 5 can body 2 and the can bottom is not necessary to tighten up the cans body formed a shoulder 3 Contact and mouth neck part 4 reduced in diameter the open end side of the bottomed cylindrical body which is integrally molded (monoblock type) It can also be applied to.

  In addition, if it is a manufacturing method of the bottle-type can with a bottom cover, as described in WO01 / 015529, it can be easily formed and coped with a bottle-type can with a long neck and neck. Therefore, the degree of freedom of shape can be improved as compared with the monoblock type.

  And in the bottle-type can 1 in this invention, it is needless to say that printed shrink may be adhered without printing on the trunk | drum 2. FIG.

  DESCRIPTION OF SYMBOLS 1 ... Bottle type can, 2 ... Body part, 3 ... Shoulder part, 4 ... Mouth neck part, 5 ... Bottom cover, 11 ... Open end part, 12 ... Curl part, 13 ... Screw part, 13a ... Screw valley part, 13b DESCRIPTION OF SYMBOLS ... Thread part, 14 ... Annular bead part (convex bead part), 14a ... An inclined surface, 15 ... Annular bead part (concave bead part), 21 ... Hem fastening roller

Claims (8)

A cup forming step in which a thermoplastic resin coating layer is formed on at least a surface corresponding to the inner surface of the can of the metal thin plate and a coated metal thin plate coated with a lubricant is punched to form a cup, and the body further has a smaller diameter from the cup. A can body forming step for forming the bottomed cylindrical body, a neck and neck forming step for reducing the diameter of one end of the bottomed cylindrical body to form a shoulder portion and a neck portion, and the neck portion In the manufacturing method of a bottle-type can comprising a curl, a screw and a bead forming step of forming a screw part and an annular bead part in the mouth and neck part while forming an opening end part at a tip of the part in the curl part,
With respect to the can body after the curl, screw, and bead forming step, the mouth neck portion above the shoulder portion and the thermoplastic resin coating layer at least on the inner surface side of the mouth neck portion above the melting point thereof Production of a bottle-shaped can characterized by comprising an amorphization step of amorphizing the thermoplastic resin coating layer on at least the inner surface side of the can and neck portion by heating and quenching immediately Method. The mouth and neck forming step includes a top dome forming step of forming a shoulder and mouth and neck by reducing the diameter of the bottom of the can including the vicinity of the bottom of the bottomed cylindrical body,
In the amorphization step, for the can with a bottom lid that opens the unopened mouth-and-neck portion and winds a bottom lid around a lower end portion of the trunk portion opposite to the mouth-and-neck portion. The method for producing a bottle-shaped can according to claim 1, further comprising the step of amorphizing the thermoplastic resin coating layer on at least the inner surface of the mouth and neck.   The amorphization step includes an induction heating step of passing the inside of the induction heating device while rotating the can body about the can axis, and a rapid cooling by immediately immersing the mouth neck of the heated can body in a cooling water tank. The bottle-shaped can manufacturing method according to claim 1, further comprising a cooling step.   In the amorphization step, the mouth and neck are immediately immersed in the cooling water bath with the mouth and neck facing downward, and rapidly cooled, and the mouth and neck with the mouth and neck facing downward with respect to the cooled can body The method for producing a bottle-shaped can according to claim 3, comprising a draining step of blowing off water droplets adhering to the section with air.   In the amorphization step, the can body is conveyed with the mouth and neck portion facing downward, and the mouth and neck portion is immersed in the cooling water tank in a state where the can axis center of the mouth and neck portion is inclined with respect to the water surface. And a cooling step in which the mouth-neck portion is tilted in a direction opposite to that when the mouth-neck portion is immersed in the cooling water tank and then taken out from the cooling water tank after the mouth-neck part is rapidly cooled. Item 5. A method for producing a bottle-shaped can according to item 3 or 4.   The amorphization step includes a cooling step in which the cooling water in the cooling water tank is convected at the same speed as the moving speed of the can body in the same direction as the moving direction of the can body in the cooling water tank. The method for producing a bottle-shaped can according to any one of claims 3 to 5, wherein the bottle-shaped can is produced. A bottle-type can with the least can inner side resin-coated metal thin plates thermoplastic resin film layer is formed on the corresponding surface to the material of the metal sheet, the thermoplastic resin film layer in the neck inner surface The degree of crystallinity (Cn) of the thermoplastic resin satisfies the following formula (1), and the degree of crystallinity (Cn) of the thermoplastic resin in the thermoplastic resin coating layer on the inner side of the mouth-and-neck portion ; A bottle-shaped can characterized in that the crystallinity (Cw) of the thermoplastic resin at the center of the body satisfies the following formula (2).
Cn <1 (1)
Cn / Cw <1 (2)
However, Cn infrared absorption intensity was measured by IR analysis (reflection infrared spectroscopy), Cn = (peak height 1340 cm ^-1) / (the peak of 1578 cm ^-1 height). Cw is IR analysis infrared absorption intensity was measured at (reflection infrared spectroscopy), Cw = (peak height 1340 cm ^-1) / (the peak of 1578 cm ^-1 height). Bottle type can according to claim 7, wherein the pre Kinetsu thermoplastic resins of the thermoplastic resin coating layer on the inner surface side of the mouth neck is amorphous.

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