TW201808623A - Laminated sheet for container and container - Google Patents

Abstract

To provide a laminated sheet for container which makes a width of a flange after molding uniform over the whole periphery and accordingly omits a trimming step, and does not cause waste of a material. A laminated sheet 10 for container has: a metal foil 101; and a heat-fusible resin film 102 which is laminated on one surface of the metal foil 101 and constitutes a container inner face. A flange outer diameter ratio of the metal foil 101 is MD/TD=1.003-1.02 and 45 DEG/TD=0.99-1.003. A breaking strength ratio of the heat-fusible resin film 102 is MD/TD=1.2-2 and 45 DEG/TD=1.1-1.6. A flange outer diameter ratio of the metal foil 101 is 0.3-2%.

Description

Laminated sheet for container and container

The present invention relates to a laminated sheet for a container made of a resin film having a single-area layer of at least metal foil and used as a molding material for a cup-shaped container, and a container formed from the same laminated sheet.

Containers for packaging contents that require long-term storage, in gas. Moisture. It is known to form laminated sheets of single-sided or double-area resin films of metal foils, such as aluminum foils, which are excellent in shielding properties such as light, and to form the laminated sheets into cups by deep drawing molding or inflation molding. For example, refer to the following Patent Documents 1 to 3).

The above container is a flange having a flange on the upper periphery of the opening and filled with the contents, for example, a laminated sheet having a heat-adhesive resin film on the aluminum foil and its inner area layer by thermal fusion. The cover material formed by the material to form a package.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2-167740

[Patent Document 2] Japanese Patent Laid-Open No. 2009-221567

[Patent Document 3] Japanese Patent Application Publication No. 2014-76462

However, in the case of a container composed of the above-mentioned laminated sheets, the width of the flange (that is, the outer diameter of the flange) after forming is not uniform throughout the circumference, resulting in inconsistencies beyond expectations.

Therefore, in the manufacturing of the above-mentioned container, in addition to the forming step of the container, a cutting step that cuts the width of the flange is often added, which results in an increase in cost and waste of materials.

An object of the present invention is to provide a laminated sheet for a container. The width of a flange formed after forming is uniform over the entire circumference. Therefore, the cutting step can be omitted without material waste.

In order to achieve the above object, the present invention includes the following aspects.

1) A laminated sheet for a container, which is a laminated sheet for a container used as a molding material for a cup-shaped container, which is characterized in that it is provided with a metal foil and laminated on one side of the metal foil and constitutes the inner surface of the container Hot-melt resin film; The outer diameter ratio of the flange of the metal foil is in the direction of 0 ° (MD) with respect to the rolling direction (TD) in the direction of 90 ° with respect to the rolling direction (TD) = 1.003 ~ 1.02, relative In the direction of rolling 45 ° direction / 90 ° direction (TD) with respect to the rolling direction = 0.99 to 1.003; The breaking strength ratio of the heat-adhesive resin film is the direction (MD) / 0 ° relative to the longitudinal direction of the film / The direction (TD) of 90 ° relative to the longitudinal direction of the film = 1.2 ~ 2, the direction of 45 ° relative to the longitudinal direction of the film / the direction (TD) at 90 ° relative to the longitudinal direction of the film = 1.1 ~ 1.6; Moreover, the outer diameter ratio of the flange of the metal foil is 0.3 to 2%.

2) The laminated sheet for containers according to the above 1), further comprising a resin film laminated on the other surface of the metal foil and constituting the outer surface of the outer surface of the container.

3) The laminated sheet for containers as described in 1) or 2) above, wherein the endurance of the metal foil is 20 to 200 MPa, and the elongation of the metal foil is 15 to 50%.

4) The laminated sheet for containers according to any one of 1) to 3), wherein the breaking strength of the hot-melt resin film is 30 to 100 MPa.

5) The laminated sheet for containers according to any one of 1) to 4) above, wherein the metal foil is an aluminum foil made of a JIS 8000 alloy and having a thickness of 40 to 200 μm.

6) A container characterized in that the laminated sheet for a container according to any one of 1) to 5) is formed into a cup shape.

The laminated sheet for container of the above 1) sets the outer diameter ratio of the flange of the metal foil, the breaking strength ratio of the hot-melt resin film, and the outer diameter ratio of the flange of the metal foil, Thereby, the width of the flange of the container after forming can be controlled uniformly.

Therefore, by using the laminated sheet of 1) above, a container having a flange having a uniform width can be formed, so that an increase in cost due to an increase in the cutting step of cutting the width of the flange can be avoided, and no waste of material is generated. In addition, with the laminated sheet of 1), the width of the container can be kept to a minimum. Furthermore, with the laminated sheet of the above 1), since the anisotropy is reduced, it is difficult to cause local elongation at the time of molding, and moldability can be improved.

Here, the "ratio of the outer diameter of the flange of the metal foil" refers to a 55 mm-diameter disc-shaped blank made of metal foil alone, using a mold of a desired shape to form an inner diameter of 33 mm and a depth of 14 mm. The outer diameter of the flange in the direction of rolling 90 ° (TD) is about 39mm, and the flange is not wrinkled, and the anti-crease pressure is adjusted to form a cup shape. The obtained molded products are individually measured 0 ° relative to the rolling direction. The outer diameters of the flanges in the directions of, 45 °, and 90 ° are based on these measured values to calculate the aforementioned ratio.

In addition, "the outer diameter ratio of the flange of the metal foil" means that the outer diameter of the flange in a total of 6 directions is measured for the above-mentioned cup-shaped molded product at 30 ° intervals with reference to the rolling direction. Average of flange outer diameter-average of flange outer diameter in two directions) / (average of flange outer diameter in two directions + average of flange outer diameter in two directions) / 2) × 100].

The laminated sheet for containers according to the above 2) can impart durability, weather resistance, dent resistance, damage resistance, and the like to the formed container.

With the laminated sheet for a container according to the above 3), it is difficult for a container to be defective in forming, and the moldability is further improved. In addition, since the laminated sheet for containers according to the above 3) does not apply excessive force to the sheet during molding, it is difficult to cause pinholes or breakage.

With the laminated sheet for container of 4), the formability is better, and it is difficult to produce a product. Delamination after shape.

Since the laminated sheet for a container according to the above 5) uses an aluminum foil made of a JIS 8000 series metal foil, the formability is better. In addition, with the laminated sheet for a container according to the above 5), since the thickness of the aluminum foil is 40 to 200 μm, the formed container not only obtains shape retention and moderate rigidity, but also does not have a high manufacturing cost.

(1) ‧‧‧container

(1c) ‧‧‧ flange

(10) ‧‧‧Laminated sheet for container

(101) ‧‧‧metal foil

(102) ‧‧‧Hot-melt resin film

(103) ‧‧‧Outside resin film

[Fig. 1] A partially enlarged sectional view showing a layer structure of a laminated sheet for a container according to an embodiment of the present invention.

[Fig. 2] A cup-shaped formed body formed of a metal foil of the same laminated sheet material: (a) a vertical sectional view, and (b) a plan view.

[Fig. 3] A cup-shaped container formed by the same laminated sheet: (a) a vertical sectional view, and (b) a plan view.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 shows a layer structure of a laminated sheet for a container according to the present invention.

The laminated sheet (10) for a container shown in the figure is a metal film (101), a heat-adhesive resin film (102) laminated on one side of the metal foil (101) and constituting the inner surface of the container (1). And a resin film (103) laminated on the other surface of the metal foil (101) and constituting the outer surface of the container (1).

Metal foil (101), giving gas to container (1). Moisture. Shielding of light, etc. Form a shielding layer that enables long-term storage of the contents.

As the metal foil (101), for example, aluminum foil, iron foil, stainless steel foil, and copper foil can be used, and aluminum foil is more suitable. In the case of aluminum foil, any one of pure aluminum foil and aluminum alloy foil is acceptable. In addition, either soft or hard, it is more suitable for JIS 8000 series alloys, that is, A8000 series (especially JIS H4160) is used. It is composed of alloys of A8079H or A8021H), especially the soft material (O material) which has been treated with blunt treatment of the alloy, thereby obtaining excellent formability.

The thickness of the metal foil (101) is not particularly limited. When an aluminum foil of JIS 8000 series alloy is used, the thickness is preferably 40 to 200 μm. As a result, the formed container obtains shape retention and rigidity, and the manufacturing cost is not reduced. Too high.

On one or both sides of the metal foil (101), a chromate treatment or other substrate treatment can be performed if necessary. Specifically, the surface of the metal foil (101) that has been degreased is coated with an aqueous solution of any of the following 1) to 3), dried, and subjected to a chemical conversion treatment to form a film: 1) containing An aqueous solution of a mixture of phosphoric acid, chromic acid, and at least one compound selected from the group consisting of metal salts of fluoride and non-metal salts of fluoride; 2) containing phosphoric acid, resins selected from acrylic resins, and chitosan derivative resins An aqueous solution of a mixture of at least one resin in the group consisting of phenol resin and chromic acid and at least one compound selected from the group consisting of chromic acid and chromium (III) salt. 3) Contains phosphoric acid, At least one resin selected from the group consisting of acrylic resin, chitosan derivative resin, and phenol resin, at least one compound selected from the group consisting of chromic acid and chromium (III) salts, and fluorine An aqueous solution of a mixture of at least one compound in a group of a metal salt of a compound and a non-metal salt of a fluoride.

The film formed on the metal foil (101) by the aforementioned chemical conversion film is preferably 0.1 mg / m ² to 50 mg / m ² of chromium, and 2 mg / m ² to 20 mg / m ² is particularly preferred. good.

The metal foil (101) constituting the laminated sheet (10) has a flange outer diameter ratio of a direction (MD) of 0 ° with respect to the rolling direction / direction (TD) of 90 ° with respect to the rolling direction = 1.003 ~ 1.02, 45 ° with respect to the rolling direction / 90 ° with respect to the rolling direction (TD) = 0.99 to 1.003, and the flange outer diameter ratio is 0.3 to 2% .

Here, referring to FIG. 2, the “flange outer diameter ratio” refers to a 55 mm-diameter disc-shaped blank made of the above-mentioned metal foil (101), and a mold having a desired shape is used to form an inner diameter (d). 33mm, depth (H): 14mm, the outer diameter (D) of the flange is about 39mm with respect to the rolling direction (TD) at 90 °, and the flange (11c) is adjusted to prevent wrinkle pressure without forming wrinkles. Thus, the obtained molded product (11) is individually measured with respect to the outer diameter of the flange (11c) in the directions of 0 °, 45 °, and 90 ° with respect to the rolling direction, and the aforementioned ratio is calculated, that is, relative to the rolling direction The outer diameter of the flange in the direction of 0 ° (MD) / the outer diameter of the flange in the direction of 90 ° (TD) with respect to the rolling direction, and the outer diameter of the flange in the direction of 45 ° with respect to the rolling direction / with respect to the rolling direction The outer diameter of the flange in the direction of 90 ° (TD).

In addition, the "flange outer diameter ratio" refers to a total of 6 directions (A1) to (A6) measured for the above-mentioned molded product (11) in a direction of 90 ° with respect to the rolling direction (A1) at 30 ° intervals. The outer diameter of the flange (11c) (refer to FIG. 2 (b)) means [(average of the outer diameter of the flanges in the two large directions-average of the outer diameter of the flanges in the small 2 directions) / ((large 2 directions Average of the outer diameter of the flange + average of the outer diameter of the flange in two small directions) / 2) × 100].

Here, in the case of a conventional laminated sheet for a container, a metal layer (specifically, an aluminum foil) is used with a low ear rate. The reason is that if the ear rate of the metal layer is large, wrinkles are easily generated on the flange of the container being molded, and defects such as breakage during molding are generated (for example, refer to the aforementioned Patent Document 1). In addition, even if the synthetic resin layers of the same laminated sheet are formed by co-extrusion, they still have orientation and anisotropy. Generally speaking, the breaking strength of the unstretched resin film is 0 ° direction (MD)> oblique direction> 90 ° direction (TD) relative to the material conveying direction, which is a certain producer. Next, a container formed by laminating a metal having a small ear ratio and a small flange outer diameter ratio, and a sheet material made of a highly anisotropic synthetic resin layer. Due to the influence of the synthetic resin layer, the flange width is formed relatively. In the material conveying direction 90 ° direction (TD)> tilt direction> 0 ° direction (MD). Therefore, the present invention is based on the premise that the anisotropy of the synthetic resin layer must be generated, and by giving the metal layer anisotropy in the direction opposite to its anisotropy, the anisotropy of the entire laminated sheet approaches zero. The anisotropy of the metal layer (that is, a metal foil such as an aluminum foil) is mainly determined based on the burn-in condition and the heat rolling rate of the intermediate burn-in.

Further, as the metal foil (101), it is suitable to use a resistance of 20 to 200 MPa (preferably 20 to 100 MPa) and an elongation of 15 to 50% (preferably 20 to 30%).

If the metal foil (101) with the endurance and elongation in the above range is used for a laminated sheet for a container (10) Poor forming of the container (1) is difficult to occur, and the formability is better. In addition, since the sheet (10) is not excessively pressed during molding, pinholes or breakage are difficult to occur.

The heat-adhesive resin film (102) constitutes the inner surface of the container (1) and the upper surface of the flange (1c), and imparts heat-sealing (heat-sealing) properties to the flange (1c) of the container (1), and It functions to protect the metal foil (101) from the contents.

The heat-adhesive resin film (102) is, for example, a polyolefin resin film such as a polypropylene (PP) resin film or a polyethylene (PE) resin film, a polyethylene terephthalate (PET) resin film, etc. Polyester resin films, polyamide resin films such as nylon (Ny) resin films, or these composite films.

In the case of a composite film, it is preferable to use a composite film in which at least two resin films are easily laminated, such as an acrylic (PP) resin film and a polyethylene (PE) resin film. If it is the said composite film, it will be easy to peel between films at the time of opening, and it will be easy to open by small force.

Specifically, for example, when the heat-adhesive resin layer constituting the innermost layer of the cover material (2) is a polyethylene (PE) resin, the heat-adhesive resin film (102) of the laminated sheet (10) for a container ), A composite film composed of a polyethylene (PE) resin film on the innermost side and a polyethylene (PE) resin film laminated on the outer side of the metal foil (101) layer.

In addition, in the case where the heat-adhesive resin film (102) is composed of the composite film, the innermost layer side (the upper surface side of the flange (1c)) of the composite film is penetrated on the flange (1c) of the container (1). ), And a notch (not shown) for opening can be provided in a ring shape with a depth reaching the upper part of the resin film on the outer side (lower side) of the resin film. In this case, the resin films constituting the composite film are easily peeled off at the time of opening, and the opening can be easily performed with a small force.

Thickness of metal foil (101) and heat-adhesive resin film (102) of laminated sheet (10) for container The ratio is preferably the thickness of the metal foil (101) / the thickness of the heat-adhesive resin film (102) = 0.24 to 1.25. If the ratio is less than 0.24, the influence of the heat-adhesive resin film becomes too large, and the outer diameter of the flange becomes unstable. On the other hand, if the above ratio exceeds 1.25, the influence of the metal foil becomes too large, and the outer diameter of the flange depends only on the anisotropy of the metal foil. The thickness of the heat-adhesive resin film is preferably about 80 to 350 μm.

Further, in the laminated sheet (10) for a container of the present invention, the thermally fusible resin film (102) has a breaking strength ratio of a direction (MD) of 0 ° with respect to the longitudinal direction of the film / 90 ° with respect to the longitudinal direction of the film The direction (TD) = 1.2 ~ 2, the direction of 45 ° relative to the longitudinal direction of the film / the direction (TD) of 90 ° relative to the longitudinal direction of the film = 1.1 ~ 1.6. By using a heat-adhesive resin film bonded with MD / TD, 45 ° / TD with a breaking strength ratio within the above range, and the aforementioned laminated sheet for containers of metal foil, the directionality and skewness of the strength of each material Cancellation of each other reduces the distortion of the container during molding, and as a result, a container having a small outer diameter inconsistency can be obtained.

The breaking strength of the hot-melt resin film (102) is more suitable for 30 to 100 MPa. Thereby, the moldability at the time of forming the container (1) from the container laminated sheet (10) is improved, and the occurrence of delamination after forming can be suppressed.

The outer resin film (103) of the container laminated sheet (10) constitutes the outer surface of the formed container (1), and fulfills the functions of imparting durability, weather resistance, dent resistance, and damage resistance to the container (1). By.

The outer resin film (103) is, for example, a polyolefin using a polyethylene (PE) resin film or an acrylic (PP) resin film (including a non-stretched polypropylene (CPP) resin film and a stretched polypropylene (OPP) resin film). Poly resin film, nylon (Ny) resin film, etc. Polyamide resin films, polyethylene terephthalate (PET) resin films, polyester resin films such as polybutylene terephthalate (PBT), or these composite materials.

The thickness of the outer resin film (103) is preferably 10 to 200 μm.

Although not shown in the drawings, the lamination of the metal foil (101) and the heat-adhesive resin film (102) and the lamination of the metal foil (101) and the outer resin film (103) are performed individually through the adhesive layer. As the adhesive layer, for example, a two-liquid curing type polyester-polyurethane resin-based adhesive or a polyether-polyurethane resin-based adhesive is used.

Fig. 3 shows a container (1) formed from the above-mentioned container laminated sheet (10).

The container (1) shown in the figure is a circular plate-shaped bottom (1a), a slightly cylindrical main body (1b) standing upright from the periphery of the bottom (1a), and the upper edge of the main body (1b). Cup shaped by flanges (1c) protruding outward in the radial direction. The shape of the container is not limited to those shown in the drawings, and can be changed as appropriate.

For the aforementioned container (1), for example, the blank sheet (10 in the case of the container of Fig. 2 in the shape of a disc) of the laminated sheet (10) for a container is used as a blank, which is provided with a punch, a die, and a cup holder (anti-wrinkle). Pressure plate) mold (not shown), by deep drawing. It can be formed by cold forming such as inflation forming.

In particular, in the case of the container (1) formed from the laminated sheet (10) for container of the present invention, the flange outer diameter ratio is small, and the outer diameter of the full-circle flange (1c), that is, the width of the flange (1c) is almost It is uniformly aligned, so it is not necessary to cut the width of the flange as in the conventional container, and no waste of materials is generated, which can reduce costs.

In this container (1), after filling the contents of food, etc., the upper opening is covered, for example, a lid (2) composed of a composite sheet having a metal foil layer and a heat-adhesive resin layer under the layer is covered. , The peripheral parts of the upper surface of the flange (1c) and the lower surface of the cover material (2) are heat-sealed to obtain a package body that seals the contents of the package.

[Example]

Next, specific examples of the present invention will be described.

<Production of laminated sheet for container>

An aluminum foil having a thickness of 120 μm made of A8021H alloy classified by JIS H4160 and having a flange outer diameter ratio and a flange outer diameter ratio shown in Table 1 below was prepared. On the surface of each aluminum foil, a chromate treatment is performed to form a chemical conversion film.

Next, on one side of each aluminum foil, a two-liquid curable polyester-polyurethane resin-based adhesive was dry-laminated as a hot-melt resin film. Each of the polypropylenes had a thickness of 300 μm and a breaking strength ratio shown in Table 1 below. (PP) resin film, and on the other side of each aluminum foil, a non-stretchable polypropylene (CPP) resin film with a thickness of 30 μm is used as a resin film by dry lamination using a two-liquid curing type polyester-polyurethane resin-based adhesive. Thus, laminated sheets for containers of Examples 1 to 2 and Comparative Examples 1 to 4 were produced.

<Shaping of container>

Next, the laminated sheets for containers of Examples 1 to 2 and Comparative Examples 1 to 4 were cut into a circular plate having a diameter of 55 mm to form a blank, and each blank was made of a die composed of a punch, a die, and a cup holder. The outer diameter of the flange is 33mm with an inner diameter of 33mm, a depth of 14mm, and a direction (TD) of 90 ° with respect to the rolling direction. The outer diameter of the flange is about 39mm, and the flange is not wrinkled to adjust the anti-crease pressure. The cups were used to obtain containers of Examples 1 to 2 and Comparative Examples 1 to 4.

For the containers of Examples 1 to 2 and Comparative Examples 1 to 4 obtained individually, a total of 6 directions (A1) were measured at intervals of 30 ° based on the direction (A1) of 90 ° with respect to the rolling direction. The flange outer diameter of (A6) (refer to FIG. 3 (b)), and the flange outer diameter ratio is calculated by the following formula.

Flange outer diameter ratio (%) = (average of flange outer diameter in two directions-average of outer flange diameter in two directions) / (average of flange outer diameter in two directions + small The average of the flange outer diameters in 2 directions) / 2) × 100 The flange outer diameter ratio of each container and its judgment are shown in Table 1.

In addition, it is determined that "◎" = flange outer diameter ratio is less than 1. 00, and the outer diameter of the flange is uniform throughout the circumference; "○" = flange outer diameter ratio is 1. 00 or more and less than 1.25, The outer diameter of the flange is uniform throughout the circumference; "△" = flange outer diameter ratio of 1.25 or more and less than 1.50, the outer diameter of the flange is slightly inconsistent throughout the circumference; "×" = flange outer diameter When the rate is above 1.50, the outer diameter of the flange is inconsistent throughout the circumference.

It is clear from Table 1 that the containers of Examples 1 and 2 have no inconsistent outer diameters of the flanges, and good results were obtained.

[Industrial availability]

The present invention can be suitably used as a container for packaging contents such as foods that need to be stored for a long time, and a laminated sheet for forming the same container.

(10) ‧‧‧Laminated sheet for container

(101) ‧‧‧metal foil

(102) ‧‧‧Hot-melt resin film

(103) ‧‧‧Outside resin film

Claims (6)

A laminated sheet for a container, which is a laminated sheet for a container used as a molding material for a cup-shaped container, which is characterized in that it is provided with a metal foil and hot-melt laminated on one side of the metal foil and constituting the inner surface of the container Adhesive resin film; The outer diameter ratio of the flange of the metal foil is the direction of 0 ° (MD) with respect to the rolling direction (TD) of 90 ° with respect to the rolling direction (TD) = 1.003 ~ 1.02, for the rolling direction 45 ° direction / 90 ° direction of rolling direction (TD) = 0.99 to 1.003; The destruction strength ratio of the heat-adhesive resin film is the direction (MD) of 0 ° relative to the longitudinal direction of the film / relative The direction (TD) of 90 ° in the longitudinal direction of the film = 1.2 ~ 2, the direction of 45 ° with respect to the longitudinal direction of the film / the direction (TD) at 90 ° with respect to the longitudinal direction of the film = 1.1 ~ 1.6; , The outer diameter ratio of the metal foil flange is 0.3 ~ 2%. The laminated sheet for containers according to item 1 of the scope of patent application, further comprising a resin film laminated on the other surface of the metal foil and constituting the outer surface of the container. The laminated sheet for containers according to item 1 of the scope of patent application, wherein the resistance of the metal foil is 20 to 200 MPa, and the elongation of the metal foil is 15 to 50%. The laminated sheet for containers according to item 1 of the scope of patent application, wherein the breaking strength of the hot-melt resin film is 30 to 100 MPa. The laminated sheet for containers according to item 1 of the patent application scope, wherein the metal foil is an aluminum foil made of a JIS 8000 alloy and having a thickness of 40 to 200 μm. A container characterized by forming a laminated sheet for a container as described in any one of claims 1 to 5 in a patent application into a cup shape.