JP5673913B2 - Deep drawing laminate and deep drawing container - Google Patents

Description

  The present invention relates to a deep-drawing laminate used in the manufacture of a retort container for packaging retort food.

  Deep drawn containers manufactured by deep drawing a laminated body in which multiple types of films are laminated are widely used for retort containers for packaging retort foods. In deep drawing, the laminated body is stretched, and the laminated body is brought into close contact with a predetermined mold using a vacuum or air pressure to produce a deep drawn container having a predetermined shape.

  Conventionally, a deep drawing laminate in which an aluminum foil is sandwiched between plastic films is used to manufacture a deep drawing container. To reduce costs, the thickness of the aluminum foil used for the deep drawing laminate is used. When the thickness is reduced to a thickness of about 30 μm to 50 μm, there is a problem that cracks that cause quality problems occur in the aluminum foil during deep drawing.

  As an invention in which the aluminum foil is not cracked during deep drawing even when the thickness of the aluminum foil used for the deep drawing laminate is reduced to about 30 μm to 50 μm, for example, in Patent Document 1, calcium carbonate An invention is disclosed in which a plastic sheet of 150 μm to 300 μm mixed with an inorganic filler as described above is used as a heat seal layer, an aluminum foil of 40 μm to 50 μm as a barrier layer, and a balanced polypropylene film as a base material layer.

Japanese Patent Publication No. 6-002367

  However, the base material layer of the deep drawing laminate must be determined according to the required specifications of the deep drawing container. As the required specification of the deep drawing container, a biaxially oriented polypropylene film is used as the base material of the deep drawing laminate. When a general-purpose heat sheet film is used for the heat seal layer, cracks that cause quality problems at the time of deep drawing occur in the aluminum foil used for the barrier layer. Manufacturing was difficult.

  Therefore, the present invention has a quality problem in deep drawing even when a biaxially stretched polypropylene film is used for the base layer of the laminate for deep drawing and a general heat sheet film is used for the heat seal layer. An object of the present invention is to provide a deep-drawing laminate and a deep-drawing container in which no cracking occurs in the aluminum foil used for the barrier layer.

In the first invention for solving the above-mentioned problem, a base material layer, a barrier layer, and a heat seal layer are laminated from the outer layer to the inner layer, and the tensile breaking elongation in the MD direction and the TD direction at 120 ° C. is 100% or more. A biaxially stretched polypropylene film is used for the base layer, and an Al-Fe-based aluminum alloy foil and nylon film with Fe content of 0.7% or more are used for the barrier layer . It is a laminated body for deep drawing for packaging .

  Since an Al-Fe-based aluminum alloy foil is easier to stretch than a pure aluminum foil, when an Al-Fe-based aluminum alloy foil is used as a barrier layer, a biaxially stretched polypropylene film is used as the base material layer. However, cracks that cause quality problems during deep drawing are not generated in the barrier layer. The Al—Fe-based aluminum alloy foil used for the base material layer may contain a metal other than Al and Fe.

In addition, when the Fe content is 0.7% or more, the Al-Fe aluminum alloy foil is easily stretched. Therefore, like the Al-Fe-based aluminum alloy foil according to JIS alloy numbers 8079 and 8021, the aluminum foil It is preferable to use an Al—Fe-based aluminum alloy foil having an Fe content of 0.7% or more for the barrier layer within a range in which the function of the above is not lost.

In addition, since a biaxially stretched polypropylene film having a tensile elongation at break of 100% or more at 120 ° C. in the MD direction and TD direction is easily stretched when heated, when the biaxially stretched polypropylene film is used as the base material layer, the barrier layer The effect of preventing cracks generated in the Al-Fe-based aluminum alloy foil can be enhanced, which is preferable.

As in the second invention , an Al-Fe-based aluminum alloy foil having a Fe content of 0.7% or more and a nylon film are used for the barrier layer, so that the Fe content is 0.5 at the time of deep drawing . Even if 7% or more Al-Fe-based aluminum alloy foil is cracked, the quality of the contents can be protected.

Furthermore, the second invention is a deep-drawn container produced by deep-drawing a laminate for deep-drawing packaging for retort food according to the first invention .

  According to the present invention described above, the present invention can be applied to a deep drawing even when a biaxially stretched polypropylene film is used as the base layer of the deep drawing laminate and a general heat sheet film is used as the heat seal layer. It is possible to provide a deep-drawing laminate and a deep-drawing container in which cracks that cause quality problems during molding do not occur in the aluminum foil used for the barrier layer.

The figure explaining the basic laminated structure of the laminated body for deep drawing concerning this invention. The figure explaining the laminated structure of the laminated body for deep drawing of an Example. The figure which plotted the fracture | rupture elongation of the laminated body for deep drawing of an Example. FIG. 1 shows an example of a deep-drawn container. FIG. 2 shows an example of a deep-drawn container.

  From this, the embodiments of the present invention will be described to the extent that those skilled in the art of the present invention can understand the contents of the present invention and implement the present invention.

  FIG. 1 is a diagram for explaining a basic laminated structure of a deep drawing laminated body according to the present invention. The basic structure of the deep drawing laminated body 1 illustrated in FIG. 1 uses a base layer 10 using a biaxially stretched polypropylene film and an Al—Fe-based aluminum alloy foil that blocks light, oxygen, hydrogen, and water vapor. The barrier layer 11 and the heat seal layer 12 using a heat-sealable film are laminated from the outer layer to the inner layer, and each layer is bonded via an adhesive.

  As shown in FIG. 1, when an Al—Fe based aluminum alloy foil is used for the barrier layer 11, the Al—Fe based aluminum alloy foil is more easily stretched than pure aluminum foil. Even when a film is used, it is possible to prevent cracking of the aluminum foil, which occurs during deep drawing and causes quality problems.

  In particular, an Al-Fe-based aluminum alloy foil having an Fe content of 0.7% or more is more easily stretched than other Al-Fe-based aluminum alloy foils as long as the function as an aluminum foil is not lost. It is preferable to use such an Al—Fe aluminum alloy foil for the barrier layer 11.

As long as the function of aluminum foil is not lost, the Al-Fe-based aluminum alloy foil with Fe content of 0.7% or more is JIS alloy with Fe content of 0.7 to 1.3%. An Al—Fe aluminum alloy foil conforming to the number 8079 or an Al—Fe aluminum alloy foil conforming to the JIS alloy number 8021 having a Fe content of 1.2 to 1.7% can be used.

  In FIG. 1, the biaxially stretched polypropylene film is a biaxially stretched polypropylene film having a tensile breaking elongation of 100% or more in the MD (MD: Machine Direction) direction and TD (TD: Transverse Direction) direction at 120 ° C. As such a biaxially stretched polypropylene film, “MF20” manufactured by Santox is commercially available.

  A biaxially stretched polypropylene film having a tensile elongation at break of 100% or more in the MD direction and TD direction at 120 ° C. is easier to stretch than other biaxially stretched polypropylene films when heated. The effect of preventing cracking can be enhanced.

  In order to maintain the barrier property even when cracks occur in the Al-Fe-based aluminum alloy foil during deep drawing, the Al-Fe-based aluminum alloy foil and nylon film are used as the barrier layer 11 of the deep-drawing laminate. Is preferably used.

  Next, characteristics of the deep drawing laminated body according to the present invention will be described with reference to examples and comparative examples of the deep drawing laminated body according to the present invention.

  FIG. 2 is a view showing a laminated structure of the deep drawing laminated body 2 in the embodiment. As shown in FIG. 2, the deep drawing laminate 2 of the example is formed by bonding a base material layer 20 using a biaxially stretched polypropylene film, an Al—Fe-based aluminum alloy foil, and a nylon film with a urethane-based adhesive. Each of the barrier layer 21 and the heat seal layer 22 using the non-axially stretched polypropylene film is manufactured by bonding using a urethane-based adhesive, and the substrate layer 20 is obtained by gravure printing, flexographic printing, offset printing, or the like. A printing layer 20 a is formed between the base material layer 20 and the barrier layer 21 by printing a predetermined pattern on the biaxially stretched polypropylene film used.

Example 1
In Example 1, in the deep drawing laminate 2 illustrated in FIG. 2, “ME-1” manufactured by Tosero Co., Ltd., 25 μm, and Al—Fe-based aluminum of the barrier layer 21 are formed on the biaxially oriented polypropylene film of the base material layer 20. “8079”, 30 μm, manufactured by Toyo Aluminum Co., Ltd. on the alloy foil, “ONM-BRT”, 15 μm manufactured by Unitika, on the nylon film of the barrier layer 21, “RXC-” manufactured by Tosero Co., Ltd. on the non-axially stretched polypropylene film of the heat seal layer 22 21 ”, 80 μm, and a predetermined pattern was printed on the inner layer side of the biaxially oriented polypropylene film of the base material layer 20.

(Comparative Example 1)
Comparative Example 1 is the same as Example 1 except that the Al—Fe aluminum alloy foil of the barrier layer 21 is changed to a pure aluminum foil (“1N30” manufactured by Toyo Aluminum Co., Ltd., 40 μm).

  As an evaluation of Example 1 and Comparative Example 1, a constant speed extension type fracture tester was used, and the fracture depths of Example 1 and Comparative Example 1 were measured under the conditions of a push rod diameter of 25 mm and a drawing speed of 10 m / min. did.

Table 1 shows the measurement results of the breaking depths of Example 1 and Comparative Example 1.

  As shown in Table 1, since Example 1 has a deeper drawing depth until it breaks than Comparative Example 1, Example 1 has a quality problem during deep drawing compared to Comparative Example 1. It was found that cracking was difficult to occur in the aluminum alloy foil in the barrier part.

(Example 2-1)
In Example 2-1, in the deep drawing laminated body 2 illustrated in FIG. “8079”, 40 μm, manufactured by Toyo Aluminum Co., Ltd. for the aluminum alloy foil, “N1202”, 15 μm manufactured by Toyobo Co., Ltd., for the nylon film of the barrier layer 21, “ZK99S” manufactured by Toray Film Processing Co., Ltd. 70 μm was used, and a predetermined pattern was printed on the inner layer side of the biaxially stretched polypropylene film of the base material layer 20.

(Example 2-2)
Example 2-2 is the same as Example 2-1 except that the nylon film of the barrier layer 21 is changed to “NAP22” manufactured by Toyobo Co., Ltd.

Example 3
Example 2-3 is the same as Example 2-1 except that the nylon film of the barrier layer 21 is changed to “Bonyl W” manufactured by Kojin Co., Ltd.

(Example 2-4)
Example 2-4 is the same as Example 2-1 except that the nylon film of the barrier layer 21 is changed to “ONM-BRT” manufactured by Unitika.

(Comparative Example 2-1)
Comparative Example 2-1 is the same as Example 1 except that the biaxially stretched polypropylene film of the base material layer 20 is changed to “ME-1” manufactured by Tosero Corporation.

(Comparative Example 2-2)
Comparative Example 2-2 is the same as Example 2 except that the biaxially stretched polypropylene film of the base material layer 20 is changed to “ME-1” manufactured by Tosero Corporation.

(Comparative Example 2-3)
Comparative Example 3 is the same as Example 3 except that the biaxially stretched polypropylene film of the base material layer 20 is changed to “ME-1” manufactured by Tosero.

(Comparative Example 2-4)
Comparative Example 4 is the same as Example 4 except that the biaxially stretched polypropylene film of the base material layer 20 is changed to “ME-1” manufactured by Tosero.

Table 2 shows the measurement results of break elongation (unit: mm) of Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-4. The tensile elongation was measured using a Tensilon universal tester, using a test piece conforming to JIS-Z1702, with a chuck distance of 80 mm and a test speed of 300 m / min.

  FIG. 3 is a graph of Table 2, and the vertical axis of FIG. As shown in FIG. 3, when Examples 1 to 4 and Comparative Examples 1 to 4 are compared, the elongation at break in the TD direction is improved. In Examples 1 to 4, the barrier layer 21 of the deep drawing laminated body 2 is improved. Even if the nylon film used for the change is changed, the balance of break elongation in the MD direction and TD direction is excellent (the difference is small). It has been found that when a stretched polypropylene film is used for the base material layer 20, the deep drawability is improved as compared with other biaxially stretched polypropylene films.

  The deep-drawing laminate described so far is used for the production of deep-drawn containers for retort foods. When manufacturing a deep-drawn container using the deep-drawing laminate according to the present invention, the deep-drawing laminate is stretched and brought into close contact with a predetermined mold using air pressure, vacuum, etc. A squeeze container is manufactured.

  FIG. 4 is a first drawing showing an example of a deep drawing container manufactured by deep drawing a deep drawing laminate, and FIG. 5 is a second drawing. In FIG. 4, the shape of the deep-drawn container manufactured by deep-drawing the deep-drawing laminate depends on the shape of the mold used for deep-drawing, and the rectangular retort container 3 shown in FIG. In addition, the round retort container 3a illustrated in FIG. 5 is widely used.

  As the deep drawing laminate according to the present invention, the deep drawing laminate of Example 1 was used, and a deep drawing container for a retort container was manufactured using a drawing die having a depth of 35 mm. And after filling 25 cc of water into a deep-drawn container and sealing the lid manufactured using the same deep-drawn laminated body to the deep-drawn container, it was heated at 121 ° for 50 minutes. There was no problem.

DESCRIPTION OF SYMBOLS 1, 2 Laminate for deep drawing 10,20 Base material layer 11,21 Barrier layer 12,12 Heat seal layer 3a Square retort container 3b Round retort container

Claims (2)

A base material layer, a barrier layer, and a heat seal layer are laminated from the outer layer to the inner layer, and a biaxially stretched polypropylene film having a tensile breaking elongation of 100% or more at 120 ° C. in the MD direction and the TD direction is applied to the base material layer. A deep-drawing laminate for packaging retort foods, characterized in that an Al-Fe-based aluminum alloy foil having a Fe content of 0.7% or more and a nylon film are used for the barrier layer. A deep-drawn container produced by deep-drawing the laminate for deep-drawing food packaging according to claim 1 .

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