JP2005193949A - Retort packaging bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retort packaging bag, which hardly allows an inner fusion of the bag to happen when holds an oily content, such as curry, and is subjected to a high temperature sterilization process, such as a retort process, keeps a citron-like skin deformation relatively inconspicuous if it is formed, and has design property that offers an original taste. <P>SOLUTION: The retort packaging bag is made of a laminated body comprising a surface base material layer, an intermediate layer, and a heat adhesive resin layer. Fine irregularities, which consist of spot projections of 0.5 to 3.0 mm in diameter and 10 to 100 μm in height each, are formed on the laminated body to reach its entire layers. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  Even when the present invention contains contents containing oil such as curry and is used for processing at a high temperature such as retort sterilization, the packaging bag does not cause internal fusion, and the packaging The present invention relates to a packaging bag for retort that does not stand out in appearance even when cocoon skin occurs in the bag.

Conventionally, a polypropylene resin having excellent heat resistance has been used as the innermost heat-adhesive resin layer of the packaging bag for retort. However, since the polypropylene-based resin is a crystalline resin, not only when it is made of a polypropylene homopolymer, but also when it is made of a copolymer such as an ethylene-propylene block copolymer that is generally used as a sealant film, it is impact resistant. In order to solve these problems, a heat-adhesive resin layer composed of an elastomer component-containing polypropylene resin in which an elastomer component is blended with a polypropylene resin has been used. . Certainly, when the elastomer component-containing polypropylene resin is used as the heat-adhesive resin layer, the impact resistance and the low-temperature sealability are improved, but the heat-adhesive resin layer made of the elastomer component-containing polypropylene resin is used. When packaging food containing a lot of oil such as curry in a retort packaging bag and performing retort processing at a high temperature, the elastomer component-containing polypropylene resin surface inside the packaging bag will be fused. In addition, the oil contained in the curry and the like is transferred to the polypropylene resin layer containing the elastomer component, and the elastomer component dispersed in the polypropylene resin absorbs the oil and swells. (Hereinafter, referred to as “coconut skin”) occurs and the appearance is unpleasant. Also, retort packaging materials are required to have a low-temperature sealing property, and packaging materials using a sealant layer having a low-temperature sealing property have the problem that the sealant layers fuse together during high-temperature sterilization, resulting in deterioration in appearance and deformation. As a composite film that prevents such problems from occurring, a composite film comprising a sealant layer made of an ethylene-α-olefin copolymer and having a surface gloss of 20 to 80% (for example, Patent Document 1) And the like, and the density of polymerized using a single-site catalyst is 0.926 to 0.946 g / cm ³ as a packaging material that prevents cocoon skin from being generated in the packaging material for retort. A retort wrapping material (see, for example, Patent Document 2) having a sealant layer made of an ethylene-α-olefin copolymer is known.
JP 2000-103021 A JP 2003-62924 A

However, in a composite film having a sealant layer with a glossiness of 20 to 80% on the surface of the ethylene-α-olefin copolymer, food containing a large amount of oil such as curry was packaged and retorted at a high temperature. In this case, it is impossible to completely prevent internal fusion of the bag, and an ethylene-α-olefin copolymer having a density of 0.926 to 0.946 g / cm ³ polymerized using a single site catalyst. When it is going to use the sealant layer which consists of a polymer, since these sealant layers are resin of a special composition, they have the faults that it is difficult to obtain and the cost is high.

  An object of the present invention is to provide an oil component such as curry in a retort packaging bag having a heat-adhesive resin layer made of an ethylene-propylene copolymer resin, an elastomer component-containing polypropylene resin, an elastomer component-containing high-density polyethylene resin, or the like. Even if it is used for applications such as retort processing where high-content contents are stored and used, it is difficult for internal fusion to occur in the packaging bag, and even if cocoon skin occurs in the packaging bag, the appearance is conspicuous It is an object of the present invention to provide a retort packaging bag that is difficult and has a unique texture and design.

  In a packaging bag made of a laminate having a surface base material layer, an intermediate layer, and a heat-adhesive resin layer, for retort having a configuration in which fine irregularities made of point-like protrusions reaching all layers of the laminate are formed on the laminate. It is a packaging bag.

  The heat-adhesive resin layer is composed of an elastomer component-containing polypropylene resin.

  The point-like protrusions have a size of 0.5 to 3.0 mm and a height of 10 to 100 μm.

  The point-like protrusions are configured to be point-like protrusions protruding to one surface side of the laminate.

  The intermediate layer of the laminate is configured by any one of aluminum foil, biaxially stretched nylon, and a laminated film of aluminum foil and biaxially stretched nylon.

  In the case of the present invention, even when the contents containing a large amount of oil such as curry are packaged and used for applications such as retort that is sterilized at a high temperature, internal fusion is unlikely to occur in the packaging bag and Even in the case of occurrence of a retort, it is possible to provide a retort packaging bag that is hardly noticeable in appearance.

  In invention of Claim 2, it can be set as the packaging bag for retorts excellent in heat resistance, impact resistance, and low temperature sealing property.

  According to the inventions of claims 3 and 4, the retort packaging bag is excellent in the effect of preventing the internal fusion of the packaging bag upon retort treatment, and has a unique texture design that is inconspicuous even when cocoon skin occurs. It can be.

  In invention of Claim 5, it can be set as the packaging bag for retorts excellent in pinhole resistance and gas barrier property.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is an enlarged plan view showing an example of a dot-like projection formed on a laminate, FIG. 3 is a cross-sectional view taken along the line II in FIG. 2, and FIG. It is an enlarged plan view which shows the other example of the dotted | punctate protrusion formed in the body, 2 is an edge thermal-bonding part, 3 is a fine unevenness | corrugation, 4 is a dotted protrusion, d is the magnitude | size of a dotted protrusion, h Is the height of the dot-like projections, and 10 is a laminate.

  The embodiment of the packaging bag for retort of the present invention is as shown in FIGS. The shape of the packaging bag is a flat four-sided sealing bag formed by the edge thermal bonding portion 2, and is composed of point-like protrusions 4 reaching the entire layer of the laminate 10 on the entire surface of the laminate 10 constituting the packaging bag. In this configuration, fine irregularities 3 are formed. In the embodiment, the fine irregularities 3 formed on the laminate 10 are formed by regularly arranged dot-like projections 4 projecting to the outer surface side when the laminate 10 becomes a packaging bag. Although the four-side sealed bag is used in the embodiment, the shape of the bag is arbitrary, and may be a shape such as a self-supporting bag.

  As shown in FIG. 2, the enlarged plan view of the point-like protrusions 4 in the embodiment is the point-like protrusions 4 regularly arranged in a grid pattern, and an enlarged cross-section of the point-like protrusions 4 in the embodiment. As shown in FIG. 3, the figure is formed so as to protrude to the outer surface side of the laminate 10 constituting the packaging bag. The point-like protrusions 4 formed on the laminate 10 have a point-d protrusion size d of 0.5 to 3.0 mm and a point-like protrusion height h of 10 to 100 μm. If the size d of the point-like projections is smaller than 0.5 mm, it becomes difficult to form the point-like projections by embossing. Conversely, if the size d of the point-like projections is larger than 3.0 mm, the protrusions The contact area becomes large and internal fusion tends to occur. In addition, when the height h of the point-like projections is smaller than 10 μm, the insulator skin becomes conspicuous and internal fusion tends to occur. It becomes difficult to form.

  In the case of the packaging bag for retort according to the embodiment, when a product containing a large amount of oil such as curry is stored and retort sterilized at a temperature of about 120 to 135 ° C., when the retort treatment is performed at a high temperature, the packaging bag Since the protrusions of the fine irregularities formed in contact with each other and the contact area becomes smaller, it is possible to prevent internal fusion from occurring and to form fine irregularities even when cocoon skin occurs in the laminate As a result, the appearance becomes inconspicuous. Moreover, since the fine unevenness 3 including the dot-like projections 4 as in the embodiment is formed on the entire surface of the laminate, it is possible to impart a design with a unique texture.

  In the embodiment, the point-like protrusions 4 are arranged in a grid pattern, but may be arranged in a zigzag grid pattern as shown in FIG. Moreover, in embodiment, although the dotted | punctate protrusion 4 is formed so that it may protrude in the outer surface side of the laminated body 10 which comprises a packaging bag, it is formed so that a dotted | punctate protrusion may protrude in the inner surface side of a laminated body. Alternatively, the dot-like protrusions may be alternately formed so as to protrude to the inner surface side or the outer surface side of the laminate. Further, the dot-like projections can be randomly arranged without being regularly arranged. Although the design of the packaging bag may vary slightly depending on the method of forming the point-like protrusions, packaging when a product containing a large amount of oil such as curry is packaged in a packaging bag and retorted at high temperatures The inner fusion of the bag can be prevented, and the effect of making the appearance inconspicuous even when cocoon skin occurs in the laminate remains the same.

  As a method of forming fine irregularities on the laminate, after preparing a laminate by laminating a base material layer, an intermediate layer, and a thermoadhesive resin layer, a heated embossing roll in which fine irregularities are formed, an embossing roll, By performing embossing using a normal embossing device that performs hot pressing using a pair of pressure rolls, fine irregularities can be formed by embossing on the entire width of the roll-shaped laminate. In embossing, it is preferable to perform embossing by pressurizing the base material layer surface of the laminate so as to be in contact with the heated embossing roll.

  As the surface base layer of the laminate, a biaxially stretched plastic film having excellent heat resistance can be used, but biaxially stretched polyethylene terephthalate (PET) is preferably used. As the intermediate layer of the laminate, aluminum foil (AL), biaxially stretched nylon (ON), a laminate film of aluminum foil and biaxially stretched nylon can be used. As the heat-adhesive resin layer of the laminate, modified polypropylene resin (PP), high-density polyethylene (HDPE) and the like can be used, but it is preferable to use a polypropylene resin blended with an elastomer component. The surface base material layer, the intermediate layer, and the heat-adhesive resin layer are laminated by dry lamination using a urethane-based adhesive. As a structure of a laminated body, they are PET / ON / AL / PP, PET / AL / ON / PP, PET / AL / PP, PET / ON / PP, etc., for example.

The top view which shows embodiment of this invention. The enlarged plan view which shows an example of the dotted | punctate protrusion formed in the laminated body. II sectional view of FIG. The enlarged plan view which shows the other example of the dotted | punctate protrusion formed in the laminated body.

Explanation of symbols

2 Edge thermal bonding part 3 Fine unevenness 4 Point protrusion
10 Laminate d Point-like protrusion size h Point-like protrusion height

Claims (5)

In a packaging bag made of a laminate having a surface base material layer, an intermediate layer, and a heat-adhesive resin layer, the laminate has a structure in which fine irregularities consisting of point-like protrusions reaching all layers of the laminate are formed. A retort packaging bag. The retort packaging bag according to claim 1, wherein the thermal adhesive resin layer is composed of an elastomer component-containing polypropylene resin. The retort packaging bag according to claim 1 or 2, wherein the dot-like projections have a size of 0.5 to 3.0 mm and a height of 10 to 100 µm. The retort packaging bag according to any one of claims 1 to 3, wherein the point-like protrusions are point-like protrusions protruding toward one surface side of the laminate. The intermediate layer of the laminate is composed of any one of aluminum foil, biaxially stretched nylon, and a laminated film of aluminum foil and biaxially stretched nylon. Retort packaging bag.

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