JP5126507B2 - Packaging bag for heat sterilization - Google Patents

Description

  The present invention contains boiled foods such as raw noodles, hams and sausages, pickles, etc., and retort foods such as curry, stew and boiled beans in a packaging bag, and is subjected to hot water heat sterilization treatment by boil treatment or retort treatment. The present invention relates to a packaging bag for heat sterilization that can visually determine the presence or absence of hot water heat sterilization treatment.

  Conventionally, as a packaging bag that can withstand hot water heat sterilization treatment of boil treatment or retort treatment, for example, a stretched polyester film, a stretched nylon film, a stretched polypropylene film, or a stretched polypropylene film having heat resistance and hot water resistance that can withstand the boil / retort treatment. A film on which an inorganic material such as aluminum oxide or silicon oxide is deposited is used as a base material layer. If necessary, a pattern printing layer is provided on the base material layer, and an unstretched polypropylene film, unstretched linear low Using a density polyethylene film, unstretched low-density polyethylene, unstretched ethylene / vinyl acetate copolymer film, a laminate in which a base material layer and a heat-adhesive resin layer are laminated via an adhesive for dry lamination, Well known are three-sided seal bags, four-sided seal bags, and self-supporting bags made from laminates. . Of course, the intermediate layer has barrier properties such as an ethylene / vinyl alcohol copolymer, aluminum foil, etc. in order to satisfy the protective functionality required for the laminate depending on the contents to be packaged, such as moisture resistance and gas barrier properties. Needless to say, the films are laminated.

  When using these packaging bags for boil processing, fill the packaging bags with contents such as raw noodles, and after sealing and sealing, taking into account the type, size, content, expiration date, etc. of the contents, for example The packaged product is manufactured by boiling at a temperature of 85 ° C. to 100 ° C. for 20 to 60 minutes. In addition, when using the above packaging bag for retort processing, fill the packaging bag with contents such as curry, vacuum or deaerate, and seal and seal the contents, taking into account the type, size, content, etc. Then, using a normal retort kettle, for example, a packaged product is manufactured by retorting under pressure at a temperature of 100 ° C. to 140 ° C. and a time of 15 to 60 minutes. However, packaged products that have been boiled or retort-treated with hot water heat sterilization are not different in appearance before and after sterilization, and the packaged products have been subjected to hot water heat sterilization or have not been processed. It is difficult to visually determine whether it is. Therefore, conventionally, as a method for confirming whether or not the boil and retort treatment has been completed or not, the color changes when heated for a certain period of time at the specified temperature in the presence of steam or hot water, and the hot water heat sterilization treatment has been performed. A method of forming an indicator ink layer by printing the indicated ink on a packaging bag by a gravure printing method is known.

  For example, the outer layer film made of resin, the base film, and the inner layer film made of resin are bonded together in the order of the adhesive layer, and water vapor at a sterilization temperature is provided at least between the outer layer film and the base film. A retort packaging sheet in which a discolorable indicator ink layer is formed is known (see, for example, Patent Document 1).

  However, in the above-mentioned retort packaging sheet, since the water vapor discoloration indicator ink layer at the sterilization temperature is formed at least partly between the outer layer film and the base film, Since the water vapor or hot water is not in direct contact with the indicator ink layer, the indicator ink layer is not easily affected by the water vapor or hot water, and it takes time for the indicator ink layer to change color. This hot water heat sterilization treatment has a drawback that the indicator ink layer may not be completely discolored. Further, the indicator ink layer is composed of either an ink containing a transition metal compound and sulfur and / or a sulfur compound, or an ink containing a monoazo dye and an organic acid and / or a metal salt thereof. There is a problem that it is a type that changes color and is not a type that completely erases color. Furthermore, there is a drawback that the ink is expensive.

  In addition, for retort consisting of a laminate having a base material layer and a heat-adhesive resin layer, and having an indicator ink layer made of ink containing an aluminum powder pigment that is erased by retort treatment on the outer surface of the base material layer Packaging bags are known (see, for example, Patent Document 2).

The problem of patent document 1 was improved by the said packaging bag for retorts. However, in recent years, sterilization conditions for retort treatment tend to be employed at high temperatures for a short time, for example, 130 ° C., 20 minutes, etc. On the other hand, with the diversification of food, depending on the contents, In order to prevent deterioration, the sterilization conditions tend to be low, for example, 90 ° C. The indicator ink layers disclosed in Patent Document 1 and Patent Document 2 are of a type that changes color or disappears by hot water heat sterilization, and the sterilization conditions are short (30 minutes or less) or low temperature (100 ° C. or less). ) Has the disadvantage that it may not be completely discolored or decolored.
JP 2003-334897 A JP 2006-219135 A

  Accordingly, the present invention has been made to solve the above-mentioned problems, and the object of the present invention is to store boiled food such as raw noodles, retort food such as curry in a packaging bag, and heat by boiling or retorting. An object of the present invention is to provide a packaging bag for heat sterilization that can easily visually determine the presence or absence of the hot water heat sterilization treatment when the water heat sterilization treatment is performed.

  In order to achieve the above object, the present invention according to claim 1 comprises a laminate having a base material layer and a heat-adhesive resin layer, and a melting point of 100 ° C. or less on the outer surface of the base material layer. A packaging bag for heat sterilization, wherein an indicator ink layer made of an ink containing a thermoplastic resin is formed, and the indicator ink layer is peeled off from the base material layer by boiling or retorting.

  Further, in the present invention according to claim 2, in the packaging bag for heat sterilization according to claim 1, the display portion is formed by printing on the inner surface of the base material layer corresponding to the region where the indicator ink layer is formed. It is characterized by comprising.

  By using the packaging bag for heat sterilization of the present invention, the thermoplastic resin in the indicator ink layer formed on the outer surface of the substrate layer by hot water heat sterilization treatment by boiling or retort treatment is caused by hot hot water. Since the indicator ink layer peels off from the base material layer due to the water flow in the boil tank or retort kettle and falls off, the presence or absence of the indicator ink layer can be visually checked for the presence or absence of the hot water heat sterilization treatment. Can be determined. By forming the indicator ink layer in this way, it is possible to prevent a packaged product that has not been erroneously sterilized by hot water from being distributed to the market, which is convenient for food manufacturers.

  Moreover, in the invention concerning Claim 2, the display part which consists of characters, such as boiled or retort sterilized, is formed in the inner surface of a base material layer by printing, and it is set as the state hidden by the indicator ink layer on the outer surface of the base material layer. Therefore, when the hot water heat sterilization process is completed, the indicator ink layer is detached from the base material layer, and characters such as boiled or retort sterilized in the display portion appear, so the hot water heat sterilization process is surely performed. It can be easily confirmed visually, and can be distinguished from a packaged product that has not been subjected to the hot water heat sterilization treatment.

The above-described present invention will be described below with reference to the drawings.
FIG. 1 is a plan view showing a first embodiment of a packaging bag for heat sterilization according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a second embodiment of the packaging bag for heat sterilization according to the present invention. 4 is a cross-sectional view taken along line BB of FIG. 3, FIG. 5 is a plan view showing a state after the hot water heating sterilization treatment of the first embodiment, and FIG. 6 is a hot water heating of the second embodiment. It is a top view which shows the state after a sterilization process, 1, 1 'is a heat sterilization packaging bag, 2 is a heat bonding part, 3 is an opening part, 4' is an indicator ink layer, 5 is a display part, 6 Is an upper end heat bonding part, 10 is a laminated body, 11 is a base material layer, 12 is a thermoadhesive resin layer, 13 is an adhesive layer, and 20 and 20 'are heat sterilization packaging bodies.

  1st Embodiment of the packaging bag for heat sterilization of this invention is as showing in FIG. 1, FIG. As shown in FIG. 1, the packaging bag 1 for heat sterilization of 1st Embodiment consists of a laminated body which has a base material layer and a thermoadhesive resin layer by the structure by which the indicator ink layer was formed in the outer surface of a base material layer. In this packaging bag, the heat-adhesive resin layers of the laminate are opposed to each other, the peripheral edges are heat-bonded to provide the heat-bonding portion 2, and the upper end is the opening 3. An indicator ink layer 4 made of ink containing a thermoplastic resin having a melting point of 100 ° C. or lower is formed on the outer surface of the lower part of the packaging bag by letter printing.

  As shown in FIG. 2, the cross-sectional configuration of the portion where the indicator ink layer 4 is provided is composed of a laminate 10 including a base material layer 11, an adhesive layer 12, and a thermoadhesive resin layer 13. The indicator ink layer 4 made of an ink containing a thermoplastic resin having a melting point of 100 ° C. or lower is formed on the outer surface of the glass.

  The indicator ink layer 4 is a thermoplastic resin in the indicator ink layer 4 formed on the outer surface of the base material layer 11 by performing hot water heat sterilization treatment by boiling treatment at 90 ° C. for about 30 minutes or retort treatment at 100 ° C. or more. Is softened or melted by hot hot water, and the indicator ink layer 4 is peeled off from the base material layer 11 due to convection of hot water in the boil tank or retort kettle or water flow generated by the rotation of the kettle. By visually observing the presence or absence of the layer 4, the presence or absence of the hot water heat sterilization treatment can be easily determined. In addition, by displaying, for example, “unsterilized” on the indicator ink layer 4, the display of “unsterilized” disappears due to the hot water heat sterilization treatment, so that the sterilized packaging product and the untreated packaging Easy to distinguish from products. In the first embodiment, the indicator ink layer 4 is displayed as “not sterilized”, but the indicator ink layer can be displayed arbitrarily, and is formed to have a pattern such as a round shape, a triangle shape, or a square shape. May be. By printing and displaying characters, symbols, patterns, etc. on the indicator ink layer 4, the display of characters, symbols, patterns, etc. will not be lost by the hot water heat sterilization process. It is easy to check whether or not The display of the indicator ink layer 4 may be a blank character shown in the first embodiment, or may be a solid print of characters and characters.

  A second embodiment of the packaging bag for heat sterilization of the present invention is as shown in FIGS. As shown in FIGS. 3 and 4, the packaging bag 1 ′ for heat sterilization according to the second embodiment includes a laminate 10 having a base material layer 11, an adhesive layer 12, and a thermoadhesive resin layer 13. This is a packaging bag in which the heat-adhesive resin layers 13 of the body 10 are opposed to each other, and the peripheral edges are heat-bonded to provide the heat-bonding portion 2 and the upper end is the opening 3. An indicator ink layer 4 ′ made of ink containing a thermoplastic resin having a melting point of 100 ° C. or less is formed on the outer surface of the lower part of the packaging bag by solid printing, and a base material corresponding to the region where the indicator ink layer 4 ′ is formed The display unit 5 is formed on the inner surface of the layer 11 by printing.

  FIG. 4 shows a cross-sectional configuration of the portion where the indicator ink layer 4 ′ is formed. As shown in FIG. 4, the indicator ink layer 4 ′ solid-printed on the outer surface of the base material layer 11 of the laminate 10 including the base material layer 11, the adhesive layer 12, and the thermoadhesive resin layer 13 is formed. In addition, the display portion 5 is formed by printing on the inner surface of the base material layer 11 corresponding to the indicator ink layer 4 ′, and the display portion 5 printed on the inner surface of the base material layer is solidly printed on the outer surface of the base material layer 11. The display portion 5 is hidden from view by the indicator ink layer 4 ′ so that the display unit 5 cannot be seen from the outside. When the hot-water heat sterilization is performed, the solid-printed indicator ink layer 4 ′ is subjected to a hot-water heat sterilization by a boil treatment at 90 ° C. for about 30 minutes or a retort treatment at 100 ° C. or higher, whereby the base material layer 11 The indicator resin layer 4 'is formed by the convection of hot water in the boil tank or the retort kettle or the water flow generated by rotation of the kettle because the thermoplastic resin in the indicator ink layer 4' formed on the outer surface of the softening or melting is softened or melted by hot hot water. Is peeled off from the base material layer 11 and dropped off. For example, a display printed as “sterilized” on the display unit 5 can be seen through the base material layer 11 from the outside. Presence / absence can be easily determined. In the second embodiment, “sterilized” is displayed on the display unit 5, but the content of the display unit 5 is arbitrary.

  The packaging bag for heat sterilization of the present invention can be easily visually confirmed from the outside whether the indicator ink layer is peeled off from the base material layer by hot water heat sterilization. Yes, the configuration and formation method of the indicator ink layer and the display unit are arbitrary, and the presence or absence of the hot water heating sterilization treatment may be easily confirmed by visual observation.

  FIG. 5 is a plan view showing a state after the hot water heat sterilization treatment of the heat sterilization packaging body 20 using the heat sterilization packaging bag 1 of the first embodiment. As shown in FIG. 5, the package 20 for heat sterilization using the packaging bag 1 for heat sterilization according to the present invention can be used for boiled or retort food or the like from the opening 3 above the packaging bag 1 for heat sterilization shown in FIG. The contents 6 are filled, and then the opening 3 is thermally bonded to form an upper end heat bonding portion 7 to form a packaged product, and then a state of hot water heat sterilization treatment is shown. By performing the water heat sterilization treatment, the indicator ink layer 4 is peeled off from the base material layer 11 and is in a state of nothing. By adopting such a configuration, it is possible to easily determine the presence or absence of the hot water heat sterilization treatment, and it is possible to prevent a packaged product erroneously displayed as “unsterilized” from being distributed to the market.

  FIG. 6 is a plan view showing a state after the hot water heat sterilization treatment of the heat sterilization packaging body 20 ′ using the heat sterilization packaging bag 1 ′ of the second embodiment. As shown in FIG. 6, the packaging body 20 ′ for heat sterilization using the packaging bag 1 ′ for heat sterilization according to the present invention is boiled or retorted from the opening 3 above the packaging bag 1 ′ for heat sterilization in FIG. It is filled with contents 6 such as food, and then the opening 3 is thermally bonded to form an upper end heat bonded portion 7 to form a packaged product, and then shows a state in which hot water heat sterilization is performed. Yes, the indicator ink layer 4 ′, which is solidly printed by performing the hot water heating sterilization treatment, peels off from the base material layer 11, and drops off, and the display of “sterilized” printed on the display unit 5 is based on the outside. The material layer 11 is visible through the material layer 11.

  As the thermoplastic resin having a melting point of 100 ° C. or lower used for the ink for forming the indicator ink layer used in the first and second embodiments, polyamide-based, polyester-based, polyacryl-based, rubber-based, polystyrene-based, polyurethane-based Examples thereof include polyacryl urethane and chlorinated polypropylene. What is necessary is just to select suitably considering the adhesiveness of a base material layer and an indicator ink layer by the kind of base material layer which prints an indicator ink layer. Of these, polyesters or polyacrylurethanes having a melting point of 80 ° C. or less are preferable because they are peeled off from the base material layer by a short hot water heat sterilization treatment. A plasticizer is preferably added to the indicator ink so that the thermoplastic resin can be easily softened in a short time. In addition, it is preferable to add a matting agent such as silica in the ink resin in order to improve the friction resistance of the indicator ink layer and make it easier for moisture to penetrate and peel in a short time. The composition of the indicator ink is not particularly limited, but the mixing ratio (parts by weight) of resin: solvent: pigment: additive may be about 5-25: 70-80: 10-15: 2-10.

  In the first embodiment, the method of forming the indicator ink layer on the outer surface of the base material layer is a pattern of a packaging bag by gravure printing on the inner surface of the base material layer 11 made of a biaxially stretched film such as a biaxially stretched polyethylene terephthalate film. When the layer is formed, the indicator ink layer 4 is formed by printing with the indicator ink on the outer surface of the base material layer 11 in register so as to correspond to the pattern layer printed on the inner surface of the base material layer 11. . In the second embodiment, the method of forming the indicator ink layer on the outer surface of the base material layer and forming the display portion on the inner surface is performed on the inner surface of the base material layer 11 made of a biaxially stretched film such as a biaxially stretched polyethylene terephthalate film. When the pattern layer of the packaging bag is formed, the display unit 5 is formed by printing so as to be at a predetermined position of the pattern layer, and the base material is aligned with the display unit 5 printed on the inner surface of the base material layer 11. The indicator ink layer 4 ′ is formed by solid printing the indicator ink on the outer surface of the layer 11. In addition, when printing indicator ink on the outer surface of the base material layer 11 and forming an indicator ink layer, the base material layer is reversed and printed by a known method.

  As the base material layer 11 constituting the laminate 10, biaxially stretched polyethylene terephthalate (PET), biaxially stretched nylon (ON), biaxially stretched polypropylene, etc., and inorganic films such as aluminum oxide and silicon oxide are deposited on these films. Film etc. are used. The heat-adhesive resin layer 13 may be any material that can withstand hot-water heat sterilization and can be heat-bonded. In the case of retort treatment, unstretched polypropylene (CPP) blended with an elastomer component, high-density polyethylene (HDPE). In the case of boil treatment, low density polyethylene (LDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ionomer, ethylene- An unstretched film such as an acrylic acid copolymer (EAA), an ethylene-ethyl acrylate copolymer, or an ethylene-methacrylic acid copolymer is used. The intermediate layer is a material that satisfies various conditions such as gas barrier properties such as moisture resistance and oxygen gas barrier properties required by the contents and pinhole resistance, puncture strength, impact strength, waist required from packaging conditions. Can be arbitrarily selected and used, and a film used for the above base layer, a biaxially stretched film such as aluminum foil (AL) and polyvinyl alcohol (PVA), saponified ethylene-vinyl acetate copolymer (EVOH), etc. is used. it can. The base material layer, the intermediate layer, and the heat-adhesive resin layer are preferably laminated by a dry lamination (DL) method using a polyester polyol or polyether polyol / isocyanate two-component adhesive.

  Next, the present invention will be described in more detail with reference to the following examples.

  15 parts by weight of a resin using a polyacryl urethane resin having a melting point of 70 ° C. as a thermoplastic resin, carbon black as a pigment, silica as an additive, and a mixed solvent of toluene / isopropyl alcohol / ethyl acetate = 4/4/2 as a solvent, A gravure ink (produced by Showa Ink Industries Co., Ltd.) prepared by mixing 73 parts by weight of a solvent, 10 parts by weight of a pigment, and 2 parts by weight of an additive was used as an indicator ink. Using a PET layer with a thickness of 12 μm as a base layer, print a picture layer on one side with a gravure printer capable of double-sided printing, register it with the picture layer, and use indicator ink at a predetermined position on the opposite side of the PET The indicator ink layer was formed by printing. A polyester polyol / isocyanate two-component adhesive is applied to the pattern layer surface and dried to provide an adhesive layer. A 50 μm-thick single-side corona-treated CPP is used as the heat-adhesive resin layer, and the corona-treated surface is the adhesive layer surface. A laminated body was produced by laminating. The laminated body was aged at 40 ° C. for 3 days and then formed into a bag to produce a flat bag for heat sterilization as shown in FIG.

  Water was sealed in the packaging bag for heat sterilization, and the package for heat sterilization shown in FIG. For retort sterilization, a rotary retort pot manufactured by Nisaka Manufacturing Co., Ltd. was used. The results are shown in Table 1.

  As shown in Table 1, the indicator ink layer was peeled off from the base material layer by boil treatment at a temperature of 85 ° C. or higher. Further, the indicator ink layer peeled off from the base material layer more easily in the retort treatment at 100 ° C. or higher. Moreover, as shown in Table 1, it became clear that the time of peeling and dropping becomes shorter as the temperature of the hot water heat sterilization treatment becomes higher.

It is a top view which shows 1st Embodiment of the packaging bag for heat sterilization of this invention. It is the sectional view on the AA line of FIG. It is a top view which shows 2nd Embodiment of the packaging bag for heat sterilization of this invention. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a top view which shows the state after the hot water heat sterilization process of 1st Embodiment. It is a top view which shows the state after the hot water heat sterilization process of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'Packaging bag for heat sterilization 2 Thermal bonding part 3 Opening part 4, 4' Indicator ink layer 5 Display part 6 Contents 7 Upper end thermal bonding part 10 Laminated body 11 Base material layer 12 Thermal adhesive resin layer 13 Adhesive Layer 20, 20 'Packaging for heat sterilization

Claims (2)

An indicator ink layer made of an ink containing a thermoplastic resin having a melting point of 100 ° C. or lower is formed on the outer surface of the base material layer, and the indicator ink layer is boiled. Or the packaging bag for heat sterilization which consists of a structure peeled from the said base material layer by a retort process. The packaging bag for heat sterilization according to claim 1, wherein the display portion is formed by printing on the inner surface of the base material layer corresponding to the region where the indicator ink layer is formed.

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