JP2012111521A - Packaging bag - Google Patents

Abstract

The present invention provides a packaging bag that can easily retain the shape of an opening after opening and is excellent in resealability and manufacturability.
A packaging bag 1 is configured such that a lower end edge portion of front and rear wall films 3a, 3b is heat-sealed with a lower seal portion 7, and both side edge portions are heat-sealed with a side seal portion 8 so that a storage portion 9 is provided. Is formed. On the inner surfaces of the wall surface films 3a and 3b, two shape holding members 12a and 12b are provided with a storage portion 9 from one side seal portion 8 to the other side seal portion 8 along the inner surfaces of the wall surface films 3a and 3b. It is heat-sealed so as to cross. The thickness of the thermoplastic resin layer 25 on the inner surfaces of the wall films 3a and 3b is 25 μm or more, and the thicknesses of the shape holding members 12a and 12b are 0.4 mm or more and 0.6 mm or less.
[Selection] Figure 1

Description

  The present invention relates to a packaging bag for packaging foods such as liquids, gels, solids, and powders, cosmetics, detergents, pharmaceutical preparations and the like.

  As a packaging form when sealing food, cosmetics, detergents, pharmaceutical preparations, etc. in liquid, gel, solid, powder, etc. with a packaging film, a resin film in which a thermoplastic resin is laminated on the inner surface side is used. A packaging form is used in which a film bag formed by sealing a side or three sides is filled with contents, and then the filling port is sealed. In these packaging forms, the contents are taken out by gripping both sides of an opening notch (notch) formed in the seal portion of the film edge and tearing the film.

  In such a conventional packaging form, since it is difficult to hold the opening end of the packaging bag in an open state, it is difficult to take out the contents, and the contents attached to the opening end of the packaging bag at the time of taking out are not easily removed. There was a problem that fingers were easily soiled. Furthermore, when a part of the contents was not used, the opening end of the packaging bag had to be sealed and stored with an adhesive tape or clip, and the handling was complicated.

  Therefore, various packaging bags have been proposed in which the opening end is held in an open state after opening to improve the takeout of the contents and the resealability after opening is taken into account, for example, Patent Documents 1 to 3 Discloses a packaging bag in which a resin shape holding member is mounted in the vicinity of the opening edge of the packaging bag.

JP 2004-2444023 A JP 2008-105679 A JP 2005-88893 A

  However, the packaging bag of Patent Document 1 has a problem of increasing the cost of the packaging bag because it uses a multi-layer shape holding tape in which a heat seal layer is laminated on the shape holding layer. Moreover, in the packaging bag of patent document 2, only the structure by which the shape maintenance member is heat-sealed to the center part of the opening width of the packaging bag which has a palm seal part is disclosed, and in the said structure, a shape maintenance member After cutting the film into a predetermined length, it is necessary to align and fuse with the film raw material constituting the packaging material, which complicates the manufacturing process and makes it difficult to continuously form packaging bags. It was.

  On the other hand, the packaging bag of Patent Document 3 uses an inexpensive single layer structure shape holding tape, but in order to solve the problem of Patent Document 2, the long shape holding member is used as a film original. A manufacturing method is conceivable in which heat sealing is continuously performed to form a side seal portion of the packaging bag and then cut together with the film raw material. However, Patent Document 3 does not describe any specific conditions for heat-sealing the long shape holding tape to the packaging bag.

  An object of this invention is to provide the packaging bag which can hold | maintain the shape of the opening part after opening easily, and was excellent also in resealability and manufacturability in view of the said problem.

  In order to achieve the above object, the present invention is formed by a laminate including at least a base material layer and a thermoplastic resin layer that is an innermost layer, and includes a storage portion in which contents are enclosed, and a side edge of the storage portion. A package having a side seal portion to be closed and a shape-retaining member having a single-layer structure that is heat-sealed to the inner surface of the laminate on both sides constituting the storage portion so as to cross between the side seal portions. The shape holding member is heat-sealed so that both end portions are sandwiched between the side seal portions, and the thickness of the shape holding member is not less than 0.4 mm and not more than 0.6 mm, and The thermoplastic resin layer has a thickness of 25 μm or more.

  Further, the present invention is a storage unit that is formed of a laminate including at least a base material layer and an innermost thermoplastic resin layer and encloses contents, and a side seal portion that closes a side edge of the storage unit And a shape-retaining member having a single-layer structure that is heat-sealed to the inner surface of the laminated body on one side that constitutes the storage portion so as to cross between the side seal portions, The shape holding member is heat-sealed so that both ends are sandwiched between the side seal portions, the thickness of the shape holding member is 0.4 mm or more and 1.0 mm or less, and the thermoplastic resin layer The thickness is 25 μm or more.

  According to the present invention, in the packaging bag configured as described above, the shape maintaining member is formed by rolling and stretching polyolefin in a uniaxial direction.

  Moreover, the present invention is characterized in that, in the packaging bag having the above configuration, the thermoplastic resin layer is formed of a resin having a melting point of 125 ° C. or lower.

  Further, the present invention is the packaging bag having the above configuration, wherein the thermoplastic resin layer is formed of at least one selected from linear low density polyethylene, low density polyethylene, medium density polyethylene, and ethylene / vinyl acetate copolymer. It is characterized by being.

  According to the first and second configurations of the present invention, the shape holding member having a single layer structure is heat-sealed so that both end portions are sandwiched between the side seal portions on the inner surface of the packaging bag, and the thickness of the shape holding member is And by making the thickness of the thermoplastic resin layer of the laminate constituting the packaging bag within a predetermined range, the sealing performance before opening, the shape retention of the opening after opening, the resealability are excellent, and the cost is low. It becomes a packaging bag that can be easily formed continuously.

  In addition, according to the third configuration of the present invention, in the packaging bag having the first or second configuration, a shape-retaining member formed by rolling and stretching polyolefin in a uniaxial direction can be used at a low cost. The packaging bag is excellent in recyclability and low environmental impact during disposal.

  Further, according to the fourth configuration of the present invention, in the packaging bag having any one of the first to third configurations, the melting point of the thermoplastic resin layer is set to 125 ° C. or less, so that the heat of the side seal portion is increased. Since it is easy to soften at the time of sealing and the gap with the shape holding member can be sufficiently filled, peeling of the shape holding member from the laminate constituting the packaging bag and a decrease in sealing performance can be suppressed.

  According to the fifth configuration of the present invention, in the packaging bag of the fourth configuration, the thermoplastic resin layer is made of linear low density polyethylene, low density polyethylene, medium density polyethylene, ethylene / vinyl acetate copolymer. By forming with at least one selected from coalescence, a thermoplastic resin layer that is inexpensive and excellent in heat sealability can be formed.

The top view of the packaging bag which concerns on 1st Embodiment of this invention. The partial enlarged view of the upper seal part 11 vicinity in the packaging bag 1 of 1st Embodiment. The top view which shows the state by which the packaging bag of 1st Embodiment was opened The top view which looked at the state which bent the opening end of the packaging bag 1 of 1st Embodiment opened from the opening end side The top view which shows the state which resealed the packaging bag 1 by folding up the upper end part of the packaging bag 1 of 1st Embodiment after opening, and also bend | folding both ends. The top view which shows the state which resealed the packaging bag 1 by folding up the upper end part of the packaging bag 1 of 1st Embodiment after opening, and also bend | folding in the middle. Sectional drawing which shows an example of the laminated body 3 which comprises the wall surface films 3a and 3b of the packaging bag of 1st Embodiment. The top view and side view which show an example of the shape holding member used for 1st Embodiment Schematic which shows the manufacturing process of the packaging bag of 1st Embodiment. Side view of first seal forming portion 31 as viewed from the downstream side (left side of FIG. 9) Sectional drawing which shows the side part seal part 8 in case the thermoplastic resin layer 25 is thin Sectional drawing which shows the side part seal part 8 in case the thermoplastic resin layer 25 is thick The top view which shows the semi-finished product of the packaging bag 1 of 1st Embodiment in which the side part seal part 8 and the upper part seal part 11 were formed in three directions The top view of the packaging bag 1 of 1st Embodiment with which the content 40 was filled, the unsealed part 37 was heat-sealed, and the lower seal part 7 was formed. The elements on larger scale near the upper seal part 11 in the packaging bag 1 of 2nd Embodiment of this invention. The top view which looked at the state which bent the opening end of the packaging bag 1 of 2nd Embodiment opened from the opening end side

  Hereinafter, the package of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view of a package according to the first embodiment of the present invention. The packaging bag 1 heat seals the lower end edges of the front and rear wall films 3a and 3b with the lower seal part 7 and heat seals both side edge parts with the side seal parts 8 so that a storage part (body part) 9 is provided. Is formed. Since the lower seal portion 7 is used as a filling port for contents, the lower seal portion 7 is set as an unsealed portion 37 (see FIG. 13) before filling the contents, and is heat sealed after filling the contents.

  Further, an opening notch 10 is provided at the opening position of the upper part of the packaging bag 1 as an opening start means in the side seal portion 8 at one end. Here, the opening notch 10 is provided as the opening means, but instead of the opening notch 10, the side seal portion 8 may be provided with a scar group region composed of a plurality of fine piercing holes.

  The upper edge portion of the packaging bag 1 is heat-sealed by the upper seal portion 11. Further, in the vicinity below the opening notch 10, two shape holding members 12 a and 12 b for holding the shape of the opening after the upper seal portion 11 is cut out from one side seal portion 8 to the other. It is heat-sealed so as to cross the storage portion 9 along the inner surfaces of the wall surface films 3 a and 3 b up to the side seal portion 8.

  FIG. 2 is a partially enlarged view of the vicinity of the upper seal portion 11 in the packaging bag 1 of the first embodiment shown in FIG. As shown in FIG. 2, the two shape holding members 12a and 12b are heat-sealed so as to face each other along the inner surfaces of the wall surface films 3a and 3b.

  Next, the opening method of the packaging bag 1 of this embodiment is demonstrated using FIG.1 and FIG.2. In addition, a uniaxially stretched film is used as the base film 20 (described later) constituting the wall surface films 3a and 3b of the packaging bag 1, and the stretching direction is made to coincide with the opening direction (left and right direction in FIG. 1). When the side seal portion 8 is torn from the opening notch 10, the wall surface films 3 a and 3 b are opened in the left-right direction in FIG. 1 along the stretching direction of the uniaxially stretched film, and the packaging bag 1 including the upper seal portion 11 is opened. The upper end is cut off. At this time, if a half-cut line for opening continuous with the notch 10 for opening is formed on the wall surface films 3a and 3b, the upper end portion of the packaging bag 1 can be cut out cleanly along the half-cut line.

  FIG. 3 shows a state where the upper end portion of the packaging bag 1 including the upper seal portion 11 is completely cut off and the packaging bag 1 is opened. Moreover, the state which looked at the opened packaging bag 1 from the opening end side is shown in FIG. In the packaging bag 1 of the present embodiment, since the shape holding members 12a and 12b are heat-sealed to the inner peripheral edge of the opening end 13 of the packaging bag 1, by bending the opening end 13 as shown in FIG. The open end 13 can be held open. As a result, the content can be easily taken out, and adhesion of the content to the hand or finger when the content is taken out can be suppressed.

  Further, as shown in FIG. 5, the packaging bag 1 can be easily resealed without using an adhesive tape or a clip by folding the opening end 13 of the packaging bag 1 once or a plurality of times and bending both ends. be able to. Accordingly, it is possible to sanitarily preserve the remaining contents by suppressing the ingress of moisture and dust into the packaging bag 1.

  In addition, as shown in FIG. 6, the opening end 13 of the packaging bag 1 is folded once or a plurality of times, and even if it is folded in the middle, it can be stored hygienically without deteriorating the contents for a while. Can do.

  FIG. 7 is a cross-sectional view showing an example of a laminate 3 constituting the wall surface films 3a and 3b of the packaging bag of the present embodiment. The laminate 3 is a laminate in which a base film 20 that is an outermost layer, a printing layer 21, a barrier layer 23, an intermediate layer 24, and a thermoplastic resin layer 25 that is an innermost layer are sequentially laminated. Dry laminate layers 22 are formed between the printing layer 21 and the barrier layer 23, between the barrier layer 23 and the intermediate layer 24, and between the intermediate layer 24 and the thermoplastic resin layer 25, respectively.

  Next, each layer which comprises the laminated body 3 is demonstrated in detail. Since the base film 20 becomes a basic material constituting the packaging bag 1, and when a barrier layer (described later) made of a metal or metal oxide thin film is provided, it becomes a base material for holding the barrier layer. They can withstand the conditions of their formation, processing, etc., and can hold them well without impairing their properties. Furthermore, when manufacturing packaging, workability, heat resistance, slipping, pin resistance It is preferable that it is excellent in hall | hole property, water vapor | steam or gas barrier property, and other various physical properties.

  As the substrate film 20 used in the present invention, a simple substance such as a uniaxial or biaxially stretched nylon film, a uniaxial or biaxially stretched polypropylene film, a uniaxial or biaxially stretched polyester resin film, or a laminate thereof is used. Or a biaxially stretched polyester resin film is particularly preferably used. Specific examples of the polyester resin film include various polyesters such as polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene-2, 6-naphthalate resin, polybutylene-2, 6-naphthalate, and polycyclohexanedimethylene terephthalate resin. Series resins can be used.

  In particular, by using a uniaxially stretched film and aligning the stretching direction and the opening direction of the packaging bag 1 (left-right direction in FIG. 1), the packaging bag 1 is easy to open and excellent in handleability.

  The uniaxially or biaxially stretched polyester-based resin film uses, for example, one or more of the above-mentioned polyester-based resins, and is formed into a film such as an extrusion method, a cast molding method, a T-die method, a cutting method, and an inflation method A method of forming a film of the above-mentioned various resins alone using a method, or a method of forming a multilayer co-extrusion film using two or more kinds of resins, and further, adding two or more kinds of resins. A polyester-based resin film is manufactured by a method of forming a film by mixing in advance before forming a film, and further stretching in a uniaxial or biaxial direction using, for example, a tenter method or a tubular method. A biaxially stretched polyester resin film can be used. As a film thickness of the base film 20, about 3-50 micrometers, More preferably, about 9-30 micrometers is desirable.

  In forming the base film 20, for example, film processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, mold release properties, flame retardancy, antifungal properties Various plastic compounding agents and additives can be added for the purpose of improving and modifying properties, electrical characteristics, strength, etc. Depending on the case, it can be added arbitrarily. In the above, as a general additive, for example, a lubricant, a crosslinking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a reinforcing agent, an antistatic agent, a pigment, and the like can be used. In addition, a modifying resin or the like can also be used.

  An antistatic coating layer may be provided on the surface of the base film 20 in order to prevent problems associated with the generation of static electricity and improve the suitability for laminating, bag making, filling and packaging, and the like. As a method for forming the antistatic coating layer, for example, a resin is used as a main component of the vehicle, and one or more antistatic agents are added thereto, and further, a plasticizer, a stabilizer, and an antioxidant are added as necessary. Add one or more additives such as additives, light stabilizers, UV absorbers, curing agents, crosslinking agents, lubricants, fillers, colorants, etc., and knead thoroughly with solvents, diluents, etc. To prepare a resin composition. Next, the resin composition is used, and this is coated or printed on the surface of the base film 20 by using a normal coating method or a printing method to form an antistatic coating layer.

  Antistatic agents include, for example, anionic surfactants, cationic surfactants, nonionic surfactants, surfactants such as amphoteric surfactants, inorganic antistatic agents such as metal powder and carbon, silicone One or more selected from antistatic agents, higher fatty acids and esters thereof, acid amides, salts, paraffinic hydrocarbons, waxes and the like can be used.

  Examples of the vehicle resin include polyethylene resins, polypropylene resins, ethylene-propylene copolymers, polyvinyl chloride resins, polyvinyl acetate resins, polyacrylonitrile resins, polystyrene resins, acrylonitrile-styrene copolymers. (AS resin), acrylonitrile-butadiene styrene copolymer (ABS resin), acrylic or methacrylic resin, polycarbonate resin, alkyd resin, phenolic resin, maleic resin, natural resin, hydrocarbon resin, polyvinyl butyral One or two selected from resins, polyamide resins, polyester resins, polyurethane resins, epoxy resins, urea resins, melamine resins, aminoalkyd resins, nitrocellulose, ethyl cellulose, chlorinated rubber, cyclized rubber, etc. It is possible to use more than.

  It should be noted that one or more of the above-mentioned antistatic agents are added to the polyester resin pellets that are the raw material of the base film 20, and after sufficiently kneading, a film is formed. Antistatic properties can also be imparted to the material film 20.

  The thermoplastic resin layer 25 only needs to be capable of being melted by heat and fusing the wall films 3a, 3b and the bottom film 3c to each other. For example, the low-density polyethylene, medium-density polyethylene, high-density polyethylene, Chain (linear) low density polyethylene, ethylene / α-olefin copolymer polymerized using metallocene catalyst (single site catalyst), polypropylene, ethylene / vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate Copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, polyolefin resin such as polyethylene or polypropylene, acrylic acid, methacrylic acid, maleic anhydride, Modified with unsaturated carboxylic acid such as fumaric acid One not selected from modified polyolefin resins to be used or two or more.

  Among these, linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, and ethylene / vinyl acetate copolymer having a melting point of 125 ° C. or lower are particularly preferable in terms of heat sealability.

  The thickness of the thermoplastic resin layer 25 may be about 10 μm to 100 μm considering only heat sealability, but the shape holding member 12 is heat-sealed to the inner surfaces of the wall surface films 3 a and 3 b as will be described later. In addition, at least 25 μm or more is required in order to improve the sealing performance of the packaging bag 1 by sufficiently embedding the shape holding members 12a and 12b in the side seal portion 8 to bring the wall surface films 3a and 3b into close contact with the shape holding members 12a and 12b. The thickness of is required.

  In addition, for example, workability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, mold release properties, flame retardancy, antifungal properties, electrical properties, strength, etc. are improved and modified. For this purpose, one or more of the above-mentioned antistatic agents are added to the melt-extruded resin constituting the thermoplastic resin layer 25, and various plastic compounding agents, additives, etc. Can be added. Examples of general additives include lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and the like. Resin etc. can also be used.

  The print layer 21 forms a desired print pattern such as a character, a figure, a symbol, or a pattern between the base film 20 and the thermoplastic resin layer 25. As a method for forming the printed layer 21, the main component is one or more of normal ink vehicles, and as necessary, a plasticizer, a stabilizer, an antioxidant, a light stabilizer, an ultraviolet absorber, a curing agent, Add one or more additives such as crosslinking agents, lubricants, antistatic agents, fillers, etc., add colorants such as dyes and pigments, and knead well with solvents, diluents, etc. Then, the ink composition is adjusted. And using this ink composition, a desired printing pattern is printed on the back surface of the base film 20 by a printing method such as gravure printing, offset printing, letterpress printing, screen printing, transfer printing, flexographic printing, etc. Form.

  The barrier layer 23 imparts a high water vapor barrier property and gas barrier property to the packaging bag 1 when the content to be enclosed is easily altered by moisture and oxygen. The barrier layer 23 can be basically used as long as it is a metal foil or a vapor-deposited film in which a metal or metal oxide is vapor-deposited. Examples of the material include silicon (Si), aluminum (Al), and magnesium. (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), etc. Metals or their oxides can be used. Preferable examples include aluminum foil, aluminum vapor-deposited polyester film, and silica vapor-deposited polyester film.

  The film thickness of the barrier layer 23 is 5 to 30 μm when the barrier layer 23 is a metal foil, and varies depending on the type of metal or metal oxide used when it is a vapor deposition film. Preferably, it is desirable to select and form arbitrarily within the range of 100 to 1000 mm. In addition, a metal or metal oxide used as the barrier layer 23 may be used as a mixture of two or more kinds to form a metal or metal oxide vapor deposition film mixed with different materials.

  When the packaging bag 1 is subjected to physically and chemically severe conditions, the intermediate layer 24 has a high sealing property, puncture resistance (pinhole resistance), heat resistance, light resistance, quality maintenance, Workability, hygiene and the like are imparted.

  As the intermediate layer 24, for example, low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate. Copolymer, ethylene-acrylic acid or methacrylic acid copolymer, methylpentene polymer, polybutene resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinylidene chloride resin, vinyl chloride-vinylidene chloride copolymer, Poly (meth) acrylic resin, polyacrylonitrile resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene styrene copolymer (ABS resin), polyester resin, polyamide resin , Poly -Any known resin film or sheet such as sulfonate resin, polyvinyl alcohol resin, saponified ethylene-vinyl acetate copolymer, fluorine resin, diene resin, polyacetal resin, polyurethane resin, nitrocellulose, etc. Can be used.

  The film or sheet may be any of unstretched and uniaxially or biaxially stretched. Preferable examples include a stretched polyester film and a stretched nylon film. In addition, a light-shielding film or sheet obtained by adding a desired additive such as a colorant or an ultraviolet absorber and kneading to form a film can also be used.

  Although the thickness of the intermediate layer 24 is arbitrary, it can be selected from a range of several μm to 300 μm. The position of the intermediate layer 24 is not particularly limited as long as it is between the base film 20 and the thermoplastic resin layer 25. For example, the order of stacking the barrier layer 23 and the intermediate layer 24 in FIG.

  The dry laminate layer 22 prevents the occurrence of delamination by firmly adhering the print layer 21, the barrier layer 23, the intermediate layer 24, and the thermoplastic resin layer 25 that constitute the laminate. Examples of the laminating adhesive constituting the dry laminating layer 22 include polyvinyl acetate adhesives, homopolymers such as ethyl acrylate, butyl, 2-ethylhexyl ester, and the like, methyl methacrylate, acrylonitrile, styrene. Polyacrylic acid ester adhesives, cyanoacrylate adhesives, and copolymers of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, and methacrylic acid. Polymer-based adhesives, cellulose-based adhesives, polyester-based adhesives, polyamide-based adhesives, polyimide-based adhesives, amino resin-based adhesives such as urea resins or melamine resins, phenolic resin-based adhesives, epoxy-based adhesives, Polyurethane adhesive, reactive (meth) acrylic adhesive Chloroprene rubber, nitrile rubber, styrene - rubber adhesive comprising a butadiene rubber, a silicone-based adhesive, an alkali metal silicate, may be used an inorganic adhesive or the like made of a low-melting-point glass or the like.

The composition system of the above-mentioned adhesive may be any composition form such as an aqueous type, a solution type, an emulsion type, and a dispersion type, and the property is any of film / sheet form, powder form, solid form, etc. Further, the bonding mechanism may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, and a hot pressure type. As a method for forming the dry laminate layer 22, the above laminating adhesive is applied to one side of both layers by, for example, a coating method such as a roll coating method, a gravure roll coating method, a kiss coating method, or a printing method. Then, it can be formed by drying a solvent or the like, and the coating or printing amount is preferably about 0.1 to 10 g / m ^{2 in} a dry state.

In addition, when using the packaging bag 1 for the use in which high sealing performance and puncture resistance are not requested | required, either the barrier layer 23 or the intermediate | middle layer 24 can also be abbreviate | omitted. If the typical structure of the wall surface film 3a is illustrated,
(1) Uniaxially stretched polyethylene terephthalate (base film 20) / printing layer 21 / polyurethane adhesive (dry laminate layer 22) / aluminum-deposited polyester film (barrier layer 23) / polyurethane adhesive (dry laminate layer 22) / Linear low density polyethylene (thermoplastic resin layer 25)
(2) Uniaxially stretched polyethylene terephthalate (base film 20) / printing layer 21 / polyurethane adhesive (dry laminate layer 22) / aluminum foil (barrier layer 23) / polyurethane adhesive (dry laminate layer 22) / polyester film (Intermediate layer 24) / polyurethane adhesive (dry laminate layer 22) / linear low density polyethylene (thermoplastic resin layer 25)
(3) Uniaxially stretched polyethylene terephthalate (base film 20) / printing layer 21 / polyurethane adhesive (dry laminate layer 22) / aluminum foil (barrier layer 23) / polyurethane adhesive (dry laminate layer 22) / linear Low density polyethylene (thermoplastic resin layer 25)
Etc.

  In the case of the layered configuration (3) above, if a strong pressure is applied when the shape retaining members 12a and 12b are sandwiched between the side seal portions 8 and heat-sealed, the aluminum foil may be cracked. Therefore, when an aluminum foil is used as the barrier layer 23, an intermediate layer 24 such as a polyester film is laminated between the aluminum foil (barrier layer 23) and the thermoplastic resin layer 25 as in the laminated structure (2). It is preferable to do.

  FIG. 8 is a plan view and a side view showing an example of a shape holding member used in the present embodiment. The shape holding members 12a and 12b are formed by stretching a polyolefin resin sheet at a total draw ratio of 10 to 40 times, preferably 15 to 35 times, and having a length L, a width W, and a thickness T. It is a layered tape-like member. Examples of the polyolefin resin constituting the shape holding member 12 include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-pentene-1 copolymer. , Ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic ester copolymer, ethylene-vinyl chloride copolymer, ethylene-propylene-butene copolymer, etc., particularly high density polyethylene is preferably used. Is done.

  Moreover, although high density polyethylene may be used independently, you may mix | blend other polyolefin with high density polyethylene. Examples of other polyolefins to be blended with the high density polyethylene include low density polyethylene, ethylene-vinyl acetate copolymer, polyvinyl acetate and the like, with a ratio of 30 parts by weight or less with respect to 100 parts by weight of the high density polyethylene. It is preferable to mix. Further, the high density polyethylene may be cross-linked.

  As will be described later, since the shape holding members 12a and 12b are cut together with the side seal portion 8 in a state where both ends are heat-sealed to the side seal portion 8 of the packaging bag 1, the shape holding members 12a and 12b The length L is equal to the widthwise dimension of the packaging bag 1. Moreover, the width W of the shape holding members 12a and 12b should just be a width which can ensure the shape retention property of the opening end 13 of the packaging bag 1, and is set to about 1 mm-10 mm, Preferably it is about 3 mm-5 mm.

  In addition, as the thickness T of the shape holding members 12a and 12b increases, the shape holding performance increases. However, as will be described later, the shape holding members 12a and 12b and the wall surface are sandwiched between the side seal portions 8 and heat-sealed. Adhesion with the films 3a and 3b may be deteriorated, and the sealing performance at the side seal portion 8 may be reduced. Therefore, in order to ensure the shape holding performance while maintaining the sealing performance of the packaging bag 1, the thickness T of the shape holding members 12a and 12b needs to be 0.4 mm or more and 0.6 mm or less.

  FIG. 9 is a schematic view illustrating a manufacturing process of the packaging bag of the first embodiment. The manufacturing method of the packaging bag of this embodiment is demonstrated using FIG. First, the laminated body 3 having a configuration as shown in FIG. 7 is manufactured and wound up in a roll shape.

  Next, the long laminated body 3 wound in a roll shape is sequentially fed out and cut by a slitter (not shown) while being folded in two in the longitudinal direction to be divided into wall surface films 3a and 3b. At this time, the wall surface film 3a has the thermoplastic resin layer 25 downward, and the wall surface film 3b has the thermoplastic resin layer 25 upward. The wall surface films 3a and 3b slit in advance to a predetermined width may be fed out from separate rolls.

  Next, the long shape holding members 12a and 12b wound in a roll shape are fed out and sandwiched at a predetermined position (the side where the opening end 13 in FIG. 3 is formed) between the wall film 3a and the wall film 3b. Then, heat sealing is performed by the first seal forming unit 31 including the heat seal bar 31a. The state which looked at the 1st seal | sticker formation part 31 from the downstream (left side of FIG. 9) is shown in FIG.

  As shown in FIG. 10, by supplying two shape holding members 12a and 12b in an overlapped manner in accordance with the arrangement of the heat seal bar 31a, the upper shape holding member 12a is placed on the wall film 3a on the lower side. The shape holding member 12b is heat sealed to the wall film 3b. Further, by interposing the heat insulating plate 35 between the shape holding member 12a and the shape holding member 12b, heat fusion between the shape holding member 12a and the shape holding member 12b is prevented. Thereby, the wall surface films 3a and 3b and the shape holding members 12a and 12b can be heat-sealed continuously at the same time.

  Next, in the second seal forming part 32 provided with the heat seal bar 32a, the edge of the wall film 3a on the upper side (left side in FIG. 10) of the shape maintaining member 12 and the wall film 3b is continuously heat sealed, A seal portion 11 (see FIG. 1) is formed.

  Thereafter, the third seal forming portion 33 is heat-sealed at a predetermined interval in the long width direction to form the side seal portion 8, and the opening notch 10 is inserted into one side seal portion 8, and the side seal is formed. Cut in the width direction at the portion 8. As a heat sealing method in the third seal forming unit 33, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, and an ultrasonic seal can be used.

  In the third seal formation part 33, since the heat seal is performed at a higher temperature and higher pressure than the first seal formation part 31 and the second seal formation part 32, the thickness of the thermoplastic resin layer 25 of the wall surface films 3a and 3b is thin. In this case, as shown in FIG. 11, the wall surface film 3a and the shape holding member 12a whose viscosity is reduced by the heat of the third seal forming portion 33, and the thermoplastic resin layer 25 between the wall surface film 3b and the shape holding member 12b are third. It will be pushed out by the pressure of the seal formation part 33, and the adhesiveness of wall surface film 3a, 3b and shape holding member 12a, 12b will fall.

  Therefore, by setting the thickness of the thermoplastic resin layer 25 to 25 μm or more as described above, as shown in FIG. 12, even if heat and pressure are applied at the third seal forming portion 33, the shape holding members 12a, 12b Therefore, the wall surface films 3a and 3b and the shape holding members 12a and 12b can be sufficiently adhered to each other.

  Further, even if the thickness of the thermoplastic resin layer 25 is 25 μm or more, if the thickness T (see FIG. 8) of the shape holding members 12a and 12b exceeds 0.6 mm, the shape holding member 12a even if the manufacturing speed is reduced. The sufficient heat is not transmitted to the contact surface of 12b, and the shape holding member 12a on the wall film 3a side and the shape holding member 12b on the wall film 3b side are not sufficiently heat-sealed. By setting the thickness T of the shape holding members 12a and 12b to 0.6 mm or less, the shape holding member 12a on the wall film 3a side and the shape holding member 12b on the wall film 3b side, which were rectangular in cross section, are deformed flat. Then, the contact surfaces of the shape holding members 12a and 12b are sufficiently heat-sealed.

  Accordingly, considering that the thickness T of the shape holding members 12a and 12b necessary for ensuring the shape holding performance of the packaging bag 1 is 0.4 mm or more, the thickness of the thermoplastic resin layer 25 is 25 μm or more and the shape. By setting the thickness T of the holding members 12a, 12b to 0.4 mm or more and 0.6 mm or less, the packaging bag 1 is excellent in shape retention and sealing performance at the open end and easy to manufacture.

  In this way, as shown in FIG. 13, a semi-finished product of the packaging bag 1 is manufactured in which the side seal portion 8 and the upper seal portion 11 are formed on three sides while leaving the unsealed portion 37. The formation position of the side seal portion 8 can be formed at a predetermined position by detecting an alignment mark (register mark) formed at the same time as the printing layer 21 with a sensor.

  Finally, a predetermined amount of contents 40 are filled from the unsealed portion 37 into the storage portion 9, and the unsealed portion 37 is heat-sealed to form the lower seal portion 7, and the first embodiment as shown in FIG. The packaging bag 1 is manufactured.

  FIG. 15 is a partially enlarged view of the vicinity of the upper seal portion 11 in the packaging bag 1 of the second embodiment of the present invention, and FIG. 16 is a view of the opened packaging bag of the second embodiment as viewed from the opening end side. . In the present embodiment, the shape holding member 12a is heat-sealed only to the wall film 3a. The top view of the packaging bag 1 is the same as that of FIG. 1 of the first embodiment. Further, the laminated structure of the laminated body 3 constituting the wall surface films 3a and 3b of the packaging bag 1, the material of the shape holding member 12, and the manufacturing process of the packaging bag 1 are also the same as those in the first embodiment, and thus description thereof is omitted. .

  Also in the packaging bag 1 of this embodiment, the open end 13 can be held in an open state by bending the open end 13 as shown in FIG. Thereby, it becomes easy to take out the contents, and it is also possible to suppress adhesion to the opening end 13 at the time of taking out the contents.

  Similarly to FIGS. 5 and 6 of the first embodiment, the upper end portion of the opened packaging bag 1 is folded once or a plurality of times, and the both end portions are further folded or folded in the middle to thereby wrap the packaging bag 1. Can be easily resealed. Accordingly, it is possible to sanitarily preserve the remaining contents by suppressing the ingress of moisture and dust into the packaging bag 1.

  In the second embodiment, only one shape retaining member 12a is heat-sealed to the side seal portion 8, so that the shape retention and resealability of the open end 13 are less than those of the first embodiment. On the other hand, since it is not necessary to heat-seal the shape holding members 12a and 12b in the third seal forming portion 33, the thickness T (see FIG. 8) of the shape holding member 12a can be increased. In the second embodiment, the thickness T of the shape holding member 12 is set to 0.4 mm to 1.0 mm in order to ensure the shape holding performance while maintaining the sealing performance of the packaging bag 1.

  The packaging bag 1 of the present invention thus obtained is used as a packaging material for food, cosmetics, detergents, pharmaceutical preparations and the like in liquid, gel, solid, and powder forms, and the contents can be taken out and resealed after opening. Therefore, it is possible to provide a packaging bag with significantly improved usability and cost.

  In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the laminated structure of the laminated body 3 shown in FIG. 7 is a preferable example, and may be a laminated structure including at least the base film 20 and the thermoplastic resin layer 25 that is the innermost layer.

  Further, the packaging bag 1 of the present invention is not limited to the four-sided seal type as shown in each of the above embodiments, and various types of packaging bags are heat-sealed by, for example, a three-sided seal type, a standing pouch type or the like. 1 can be manufactured.

  Further, the above production method is only a preferred example. For example, as a production method of the laminate 3, a lamination method used when producing an ordinary packaging material, for example, a wet lamination method, a solvent-free lamination method, a coextrusion lamination, or the like. The method, the inflation method, and other methods can also be used.

  Further, when the above layers are laminated, if necessary, pretreatment such as anchor coating treatment, corona discharge treatment, ozone treatment, flame treatment, blast treatment, etc. can be optionally applied to the surface of the substrate to be laminated. . Hereinafter, the configuration of the present invention will be described more specifically using examples.

  (1) A uniaxially stretched polyethylene terephthalate film having a thickness of 12 μm is used as the base film 20, a printed layer 21 is formed on the surface of the base layer 20 by gravure printing, and a dry laminate layer 22 is further laminated. As the barrier layer 23, an aluminum-deposited polyethylene terephthalate film having a thickness of 12 μm was laminated. Furthermore, after laminating the dry laminate layer 22 on the surface of the barrier layer 23, a polyethylene film having a thickness of 25 μm was laminated as the thermoplastic resin layer 25 to produce a laminate 3 as shown in FIG.

  (2) The laminate 3 produced in the above (1) and the shape holding members 12a and 12b having a width of 4 mm and a thickness of 0.4 mm made of stretched high-density polyethylene resin (trade name Forte, manufactured by Sekisui Molding Industry Co., Ltd.) The semi-finished product of the packaging bag 1 as shown in FIG. 11 was manufactured by using the manufacturing process shown in FIG.

  (3) The packaging bag 1 manufactured in (2) above is filled with snack confectionery as the contents 40 from the unsealed portion 37, and the unsealed portion 37 is heat-sealed, as shown in FIG. A packaging bag 1 was produced.

  The packaging bag 1 of 2nd Embodiment was manufactured by the manufacturing process similar to Example 1 using the laminated body 3 and the shape holding member 12a which were used in Example 1. FIG.

  Sealing when the thickness T of the shape retaining member 12 of the packaging bag 1 of the first embodiment manufactured in Example 1 is changed in four stages of 0.2 mm, 0.4 mm, 0.6 mm, and 0.8 mm. And the shape retention of the opening were evaluated. The sealing property of the packaging bag 1 was evaluated by the heat-sealing property between the shape holding members 12 a and 12 b when forming the side seal portion 8 in the manufacturing process of the packaging bag 1. The evaluation criteria were ◎ for a level that was sufficiently sealed without reducing the production rate, ○ for a level that could be sealed if the production rate was reduced, and × for a level that was difficult to seal. The evaluation result was an average level when 20 bags of each sample were manufactured.

  The shape retainability of the opening is determined by opening the packaging bag 1 and then opening the opening end 13 by hand and then leaving the opening end 13 for 5 minutes, and after opening the opening end 13 as shown in FIG. The shape after 5 minutes when the part was bent and resealed was visually confirmed. As the evaluation criteria, a level where there is no visual change in shape is indicated by ◎, a level where there is a change in shape but there is no problem in practical use, and a level where there is no shape retention is indicated by ×. The evaluation result was an average level for 20 samples of each condition. Table 1 summarizes the evaluation results of the sealing performance and shape retention.

  As is apparent from Table 1, the packaging bag 1 using the shape holding members 12a and 12b having a thickness of 0.2 mm and 0.4 mm can obtain a good sealing performance without reducing the production speed, and has a thickness of 0. The packaging bag 1 using the 6 mm shape retaining member 12 could be sealed if the production speed was reduced. On the other hand, in the packaging bag 1 using the shape holding members 12a and 12b having a thickness of 0.8 mm, the shape holding members 12a and 12b were not sufficiently heat-sealed even if the production speed was lowered, and sealing was difficult. .

  On the other hand, regarding the shape retention at the time of opening and resealing, the shape did not change even after 5 minutes in the packaging bag 1 using the shape retention member 12 having a thickness of 0.4 mm and 0.6 mm. On the other hand, in the packaging bag 1 using the shape holding members 12a and 12b having a thickness of 0.2 mm, the shape holding property after 5 minutes was not present and it was not practical.

  The thickness T of the shape-retaining member 12a of the packaging bag 1 of the second embodiment manufactured in Example 2 is changed in five stages of 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, and 1.0 mm. The sealing property and the shape retention of the opening were evaluated. The evaluation method and evaluation criteria were the same as in Example 3. Table 2 summarizes the evaluation results of the sealing performance and shape retention.

  As is apparent from Table 2, the packaging bag 1 using the shape holding member 12a having a thickness of 0.2 mm, 0.4 mm, 0.6 mm, and 0.8 mm has good sealing performance without reducing the production speed. In the packaging bag 1 using the shape holding member 12a having a thickness of 1.0 mm, the packaging bag 1 can be sealed if the manufacturing speed is reduced.

  On the other hand, for shape retention at the time of opening and resealing, the shape does not change even after 5 minutes in the packaging bag 1 using the shape retaining member 12a having a thickness of 1.0 mm, the thickness is 0.4 mm, In the packaging bag 1 using the 0.6 mm and 0.8 mm shape holding members 12a, although the shape change was observed, the level was not a problem in practical use, whereas the shape holding member 12a having a thickness of 0.2 mm was used. The packaging bag 1 used was not practical because it did not retain shape after 5 minutes.

  INDUSTRIAL APPLICABILITY The present invention can be used for a packaging bag for packaging food, cosmetics, detergents, pharmaceutical preparations, and the like that are liquid, gel, solid, and powder as contents. By using the present invention, it is possible to provide a packaging bag that is excellent in sealing performance before opening, shape retention of the opening after opening, and resealability, and that can be continuously formed at low cost.

DESCRIPTION OF SYMBOLS 1 Package 3 Laminated body 3a, 3b Wall film 7 Lower seal part 8 Side seal part 9 Storage part 10 Notch for opening 11 Upper seal part 12a, 12b Shape holding member 13 Open end 20 Base film 21 Print layer 22 Dry laminate Layer 23 Barrier layer 24 Intermediate layer 25 Thermoplastic resin layer 31 First seal forming part 32 Second seal forming part 33 Third seal forming part

Claims (5)

A storage unit that is formed of a laminate including at least a base material layer and a thermoplastic resin layer that is an innermost layer, and encloses contents,
A side seal portion for closing a side edge of the storage portion;
A shape-retaining member having a single-layer structure that is heat-sealed to the inner surface of the laminated body on both sides constituting the storage portion so as to cross between the side seal portions;
A packaging bag having
The shape holding member is heat-sealed so that both end portions are sandwiched between the side seal portions, the thickness of the shape holding member is 0.4 mm or more and 0.6 mm or less, and the thermoplastic resin layer The packaging bag is characterized by having a thickness of 25 μm or more. A storage unit that is formed of a laminate including at least a base material layer and a thermoplastic resin layer that is an innermost layer, and encloses contents,
A side seal portion for closing a side edge of the storage portion;
A shape-holding member having a single-layer structure that is heat-sealed to the inner surface of the laminated body on one side that constitutes the storage portion so as to cross between the side seal portions;
A packaging bag having
The shape holding member is heat-sealed so that both end portions are sandwiched between the side seal portions, the thickness of the shape holding member is not less than 0.4 mm and not more than 1.0 mm, and the thermoplastic resin layer The packaging bag is characterized by having a thickness of 25 μm or more.   The packaging bag according to claim 1 or 2, wherein the shape maintaining member is formed by rolling and stretching a polyolefin in a uniaxial direction.   The packaging bag according to any one of claims 1 to 3, wherein the thermoplastic resin layer is formed of a resin having a melting point of 125 ° C or lower.   The thermoplastic resin layer is formed of at least one selected from linear low density polyethylene, low density polyethylene, medium density polyethylene, and ethylene / vinyl acetate copolymer. Item 5. A packaging bag according to any one of Items 4.

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