JP5901035B1 - Food storage bags - Google Patents

Abstract

Disclosed is a microwave oven-heating type food storage bag that is unlikely to cause a situation in which a heat seal at a notch formation portion is inadvertently removed when food is stored inside. A food storage bag is constituted by an antifogging polypropylene resin film laminate obtained by dry laminating two types of antifogging agent-containing stretched polyethylene resin films. A semicircular cutout 2 having a diameter of about 5 mm is formed at the center (left and right center) of the end edge on the back side (end edge on the folding side), and a heat of 0.3 mm width is formed around it. A seal portion 3 is provided. Further, a zipper made of synthetic resin (a type in which a long ridge is fitted into a long concave groove) 4 is fused to the opening, and can be sealed and opened. [Selection] Figure 1

Description

  The present invention relates to a food storage bag that has both a function of suppressing physiological respiration of fruits and vegetables, fermented foods and the like to maintain freshness during distribution and storage, and a function of being put into a microwave oven as it is and capable of cooking by heating. is there.

  As a synthetic resin bag for storing foods, a notch is formed in at least one portion of a bag made of a synthetic resin film, and the periphery of the notch is heat-sealed, and the periphery of the notch By designing the heat seal part of the heat seal part to be lower than the tear strength and peel resistance of other parts, the heat seal part around the notch peels off when the internal pressure rises during heating with a microwave oven. There is known a structure in which a notch is opened and water vapor is allowed to escape from the opened notch (Patent Document 1).

JP 2004-306984 A

  However, when the food storage bag as described in Patent Document 1 stores food inside, the heat seal for the notch formation is inadvertently peeled off, and the freshness of the stored food cannot be maintained. There was a risk of it occurring.

  The object of the present invention is to solve the problems of the conventional food storage bag, and to cope with microwave heating, which is unlikely to cause the heat seal of the notch forming part to be inadvertently removed at the stage of storing food inside. An object of the present invention is to provide a storage bag for maintaining the freshness of food of a mold.

The invention described in claim 1 is formed in a bag shape having an opening that can be released and sealed by a synthetic resin film or an opening that can be sealed, and a notch is formed at least at one end of the edge. And the periphery of the notch is heat sealed, and when the internal pressure is increased in a sealed state, the heat seal around the notch is separated and the notch is opened, The synthetic resin film is an antifogging polypropylene resin film laminate formed by laminating a plurality of polypropylene resin films containing an antifogging agent, and a bag comprising the antifogging polypropylene resin film laminate. The breaking elongation in the width direction is 220% or more and 250% or less.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, a second heat seal part is provided closer to the opening than the heat seal part around the notch. Is.

  The invention according to claim 3 is the invention according to claim 1 or claim 2, and is a rectangular three-sided bag, and the notches are formed so as to be substantially bilaterally symmetrical at the left and right ends thereof. It is characterized by being.

  The food storage bag according to claim 1 is provided with a notch that functions as an escape hole for water vapor during heating in a microwave oven, and is composed of an anti-fogging polypropylene resin film, and Since the elongation at break is adjusted within a predetermined range, it is unlikely that the heat seal of the notch formation part will be inadvertently removed at the stage of storing food. In the case of heating in the range, the heat seal around the notch is peeled off beautifully to open the notch forming portion, and the saturated water vapor can be discharged efficiently. Therefore, it is possible to warm the stored food. In addition, good anti-fogging properties can be exhibited, and even when the fruits and vegetables are stored in the store, the situation in which the stored items are difficult to see due to condensation or the like does not occur.

  The food storage bag according to claim 2 is provided with a second heat seal portion (second heat seal portion) on the opening side of the heat seal portion (first heat seal portion) around the notch. Therefore, it is more practical that a situation in which the heat seal of the notch forming part is inadvertently removed at the stage of storing food is less likely to occur.

In the food storage bag according to claim 3, since the two cutouts are provided so as to be symmetrical with respect to the heat seal portions at the left and right ends, the holes of the cutouts can be designed to be small. Therefore, it is possible to prevent the situation where the heat seal of the notch formation part is inadvertently removed at the stage of storing the food at a higher level. In addition, when heating with a microwave oven in a state where food is stored, the saturated water vapor inside is released to the outside from a plurality of locations, so that the stored food can be made plump.

It is explanatory drawing which shows the outline of a food storage bag.

  In addition, the food storage bag according to the present invention needs to be constituted by an antifogging polypropylene resin film laminate formed by laminating a plurality of polypropylene resin films containing an antifogging agent. Various materials can be used as the polypropylene resin that is a raw material of the polypropylene resin film, but it is preferable to use a crystalline polypropylene resin. Further, among crystalline polypropylene resins, it is more preferable to use an n-heptane-insoluble isotactic propylene homopolymer or a copolymer of polypropylene containing 60% by mass or more of propylene and another α-olefin. preferable. When the propylene homopolymer and the copolymer of propylene and another α-olefin are used, they can be used alone or in combination. In addition, n-heptane insoluble means n-heptane insoluble according to Ministry of Health and Welfare Notification No. 20 in February 1982, and the elution amount when extracted at 25 ° C. for 60 minutes is 150 ppm or less (use temperature is 100 ° C.). The excess is 30 ppm or less).

  As the antifogging agent to be contained in the polypropylene resin film, a nonionic surfactant can be used, and one that exhibits antistatic properties in combination with antifogging properties by bleeding out to the film surface is used. Is preferred. Such antifogging agents include nonionic surfactants such as fatty acid esters of polyhydric alcohols, higher fatty acid amines, higher fatty acid amides, higher fatty acid amines and amide ethylene oxide adducts. Can be mentioned. Among these antifogging agents, it is preferable to use a polyoxyethylene alkylamine type, a polyoxyethylene alkylamine fatty acid ester type, and a fatty acid glycerin ester type in combination.

  The amount of the antifogging agent added to the polypropylene-based resin film is not particularly limited, but is preferably 0.1 to 1.5% by mass and more preferably 0.2 to 1.2% by mass with respect to all layers. 0.3 to 1.0% by mass is particularly preferable. If the addition amount of the antifogging agent is less than 0.1% by mass, the antifogging property is insufficient, and it is not preferable because the contents are difficult to see when the food is stored, packaged and displayed. In addition, if the added amount exceeds 1.5% by mass, it is not preferable because it is excessively expensive and uneconomical.

  As the antifogging polypropylene resin film, a single layer can be used, but a two-layer laminated film having a base material layer and a heat-sealing layer, a base material layer thereof, It is also possible to use a laminated film of three or more layers in which an intermediate layer is provided between the layers.

  Further, as described above, when a laminated film is used, it is preferable that the antifogging agent to be added is selectively present on the surface of the heat-sealing layer. Therefore, from the layer adjacent to the heat-sealing layer or the layer on the opposite side of the heat-sealing layer, the concentration of the antifogging agent blended in each layer is added so as to become gradually thinner. It is preferable. By doing so, it is possible to obtain an effect that the added antifogging agent shifts from a layer having a high concentration to a layer having a low concentration and is expressed on the surface of the heat-sealing layer.

  The antifogging polypropylene resin film laminate constituting the food storage bag according to the present invention is formed by laminating the above antifogging polypropylene resin film (single layer or multilayer) (for example, The laminate is integrated by a method such as dry lamination. In addition, as an adhesive for laminating used in such dry laminating, a polyvinyl acetate adhesive, a homopolymer such as ethyl acrylate, butyl, 2-ethylhexyl ester or the like and methyl methacrylate, acrylonitrile Polyacrylic acid ester adhesives, copolymers of styrene, etc., cyanoacrylate adhesives, copolymers of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid, etc. Ethylene copolymer adhesives, cellulose adhesives, polyester adhesives, polyamide adhesives, polyimide adhesives, amino resin adhesives made of urea resin or melamine resin, phenol resin adhesives, epoxy adhesives Agent, polyurethane adhesive, reactive (meth) acrylic acid Use of adhesives, chloroprene rubber, nitrile rubber, inorganic adhesives made of styrene-butadiene rubber, silicone adhesives, alkali metal silicates, inorganic adhesives made of low-melting glass, and other adhesives it can.

  Among these adhesives, aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate, or aliphatic polyisocyanates such as hexamethylene diisocyanate and xylylene diisocyanate. Polyether polyurethane resins, polyester polyurethane resins, polyacrylate polyurethane resins obtained by reacting polyfunctional isocyanates such as narate with polyether polyols, polyester polyols, polyacrylate polyols, and other hydroxyl group-containing compounds When a resin-based material is used, the anti-fogging polypropylene resin film laminate has good flexibility and flexibility, and the anti-fogging polypropylene resin film laminate On easily adjust the elongation at break, it is possible to improve the processing characteristics of the printing process and the like of the antifogging polypropylene resin film laminate preferable.

In addition, the composition system of the above-described adhesive may be any composition form such as an aqueous type, a solution type, an emulsion type, and a dispersion type, and the properties of the composition are not particularly limited. Moreover, the usage-amount of an adhesive agent is although it does not specifically limit, It is preferable in it being 0.1-10 g / m < ² > (dry state). In addition, lamination can be performed by roll coating, gravure coating, kiss coating, or other coating methods or printing methods.

  The antifogging polypropylene resin film laminate constituting the food storage bag according to the present invention has a breaking elongation in the longitudinal direction (breaking elongation when pulled by a method based on JIS-K-7127) of 220. % Or more and 250% or less, and more preferably 225% or more and 245% or less. When the elongation at break is less than 220%, the heat seal around the notch is easily peeled off even with a slight impact. On the contrary, when the elongation at break exceeds 250%, when heating in a microwave oven, It is not preferable because the heat seal around the notch is difficult to peel off and the notch is difficult to open.

  The food storage bag according to the present invention can be formed by stacking two antifogging polypropylene resin film laminates and heat-sealing the surroundings. The shape of the food storage bag is not limited to the three-sided bag, and may be various shapes such as a retort pouch.

  In addition, the food storage bag according to the present invention needs to have a notch formed in at least one place on the edge. This notch functions as a discharge hole for discharging saturated water vapor when the food is stored and heated inside the food storage bag. The shape of the notch is not particularly limited, and may be a circle, an ellipse, a semicircle, a rectangle, or the like. Further, the position of the notch is not particularly limited, but it is preferable that the notch is located at the front and rear or left and right edges because the heat seal portion around the notch is not carelessly peeled when storing food. Further, the number of notches is not limited to one, and two or more can be provided. Furthermore, it is preferable to provide an even number (2, 4, 6, etc.) of the notches symmetrically because heating spots on the stored food are reduced when heated in a range.

  Furthermore, it is necessary that the periphery of the above-mentioned notch be heat-sealed (first heat-sealed portion). The shape of the heat seal is not particularly limited, but when the notch is circular, it is preferably a concentric fan shape adjacent to the notch. In addition, the method of heat sealing around the notch is not particularly limited, but when the food storage bag is heat-sealed (blown seal), when the food storage bag is heated in a microwave oven Since the heat seal portion around the notch needs to be peeled off preferentially, the heat seal strength needs to be lower than that of the outer heat seal portion. As a method for making the heat seal strength of the heat seal portion around the notch lower than the heat seal strength of the outer heat seal portion, various methods can be adopted. A method of lowering, a method of reducing the width of the heat seal portion, and the like can be suitably used.

  In addition, the food storage bag according to the present invention may be provided with a second heat seal portion on the opening side of the heat seal portion around the notch. The installation position of the second heat seal portion is not particularly limited as long as it is in the vicinity of the notch (a distance of about 2 mm to 10 mm). Further, the shape of the second heat seal portion is not particularly limited, and may be various shapes such as a linear shape having a predetermined thickness and an arc shape. In addition, when the second heat seal portion is linear, it can be provided parallel to the edge of the opening, or when notches are provided on the left and right edges of the food packaging bag. It is also possible to provide an inclined shape with respect to the edge of the opening.

  In addition, the food storage bag according to the present invention can be provided with a zipper or the like at the opening so that the bag can be sealed and released. As such a zipper, it is formed of a synthetic resin such as polyethylene or polypropylene, and various commercially available types such as a type in which a belt-like convex portion is fitted into a belt-like concave portion can be suitably used. Furthermore, the food storage bag according to the present invention is not limited to one provided with an opening that can be sealed and releasable (opening that can be sealed and opened), but is provided with a simple opening (that is, an opening). A zipper or the like is not provided in the part, and the opening can be sealed by a method such as heat sealing after storing food (such as a three-sided bag)).

  In addition, the thickness of the antifogging polypropylene resin film laminate constituting the food storage bag is not particularly limited, but it is preferable to carry out in the range of 5 to 150 μm. It is not preferable because film formation is difficult or handling is difficult. Further, the thickness of each layer is not particularly limited, but when exemplified in a preferable three-layer structure, the base material layer is 20 to 90% of the total thickness, and the heat-sealing layer is 0.85. 15% and the intermediate layer are preferably set in the range of 10 to 80%. If the ratio of the base material layer is low, the film becomes unwieldy and difficult to handle, and the effect of preventing the antifogging agent from being attracted to the laminating adhesive may be reduced. If the ratio is high, the waist is lost, and problems such as poor slipping and blocking resistance may occur. On the contrary, when the ratio of the base material layer is high and the ratio of the heat-sealing layer is high, sufficient stickiness and strength may not be obtained at the time of sealing, which is not preferable. On the other hand, the intermediate layer is not particularly limited and can be arbitrarily set within a range not impairing the characteristics of the present invention.

  In addition, the antifogging polypropylene resin film laminate has the same kind of polypropylene resin layer and other resin layers such as ethylene-acetic acid on the surface of the base material layer for the purpose of further improving the adhesive strength at the time of lamination. A resin such as a saponified vinyl copolymer or a gas barrier resin layer such as polyvinyl alcohol may be further laminated, and is not particularly limited as long as the properties of the present invention are not impaired.

  In addition, the resin forming each layer of the antifogging polypropylene-based resin film laminate includes various additives, fillers, such as heat stabilizers and antioxidants, as long as the properties of each layer are not impaired as required. , Light stabilizer, lubricant, nucleating agent, flame retardant, pigment, dye, calcium carbonate, barium sulfate, magnesium hydroxide, mica, talc, clay, zinc oxide, magnesium oxide, aluminum oxide, antibacterial agent, natural degradability Additives to be added can be added. Furthermore, other thermoplastic resins, thermoplastic elastomers, rubbers, hydrocarbon resins, petroleum resins, and the like may be blended within a range that does not impair the characteristics of the film of the present invention.

  Moreover, the antifogging polypropylene resin film laminate can be arbitrarily produced by a known method, and the production method is not particularly limited. For example, after melt lamination by T-die method or inflation method using an extruder suitable for the number of layers, it is cooled by a cooling roll method, water cooling method or air cooling method to form a laminated film, sequentially biaxial stretching method, simultaneous biaxial Examples of the stretching method include a stretching method and a tube stretching method. In addition, when the anti-fogging laminated polypropylene resin film according to the present invention is produced by the sequential biaxial stretching method, the resin melt-extruded from the T-type die is cooled and solidified by a casting machine, Create a sheet. At this time, the roll temperature for melt casting is preferably set between 15 ° C. and 40 ° C. for the purpose of suppressing crystallization of the resin and improving transparency. Next, after heating the raw sheet to a temperature suitable for stretching, the sheet is stretched in the flow direction of the sheet using the difference in speed between the stretching rolls. Considering this, it is preferable to set between 3 and 6 times. Next, both ears of the longitudinally stretched sheet are gripped by a tenter clip, and stretched while being sequentially expanded in a direction perpendicular to the flow of the sheet while being heated to a temperature suitable for stretching with hot air. In this case, the transverse draw ratio is preferably set between 7 times and 10 times in consideration of thickness variation and productivity.

  Hereinafter, the food storage bag according to the present invention will be described in more detail by way of examples. However, the food storage bag of the present invention is not limited to the embodiments of the examples and does not depart from the spirit of the present invention. Thus, it can be changed as appropriate. Moreover, the physical property and the evaluation method of a characteristic in an Example and a comparative example are as follows.

<Tensile modulus>
In accordance with JIS-K-7127, a film having a width of 10 mm and a length of 200 mm was measured with a tensile tester (AG-20KN × Dplus) manufactured by Shimadzu Corporation at a distance of 100 mm between chucks and a pulling speed of 200 mm at 20 ° C. It calculated from the initial value at the time of pulling at / min. In addition, the measurement of the said tensile elasticity modulus is the longitudinal direction (MD direction: width direction of a food storage bag) of a roll-shaped film, and the width direction (TD direction: height direction of a food storage bag) of a roll-shaped film. It carried out about.

<Elongation at break>
In accordance with JIS-K-7127, a film having a width of 10 mm and a length of 200 mm was measured with a tensile tester (AG-20KN × Dplus) manufactured by Shimadzu Corporation at a distance of 100 mm between chucks and a pulling speed of 200 mm at 20 ° C. The elongation at break was determined by obtaining the elongation at break. In addition, the measurement of the said breaking elongation was implemented about the longitudinal direction of the roll-shaped film, and the width direction of the roll-shaped film similarly to the measurement of the above-mentioned tensile elasticity modulus.

<Peeling of steam hole when storing contents>
Open the opening of the food storage bag (width × height = 150 mm × 220 mm openable zippered three-sided bag) obtained in the examples and comparative examples, and open a lump of storage (broccoli 100 g) near the opening Dropped from. Then, the peeled state of the heat seal around the cutout (steam hole) of the food storage bag after dropping the stored item was visually evaluated in the following three stages.
○: No peeling is observed in the heat seal around the notch.
(Triangle | delta): Peeling is recognized by a part (approximately 1/2 or less) of the heat seal around a notch.
X: The heat seal around the notch was almost peeled off.

<Print ink peeling (dirt in the range)>
After storing 100 g of broccoli in the food storage bags (width × height = 150 mm × 220 mm openable zippered three-sided bags) obtained in the examples and comparative examples, they are left in an atmosphere at 7 ° C. for about 24 hours. The contents were cooled down sufficiently. Thereafter, the food packaging bag was placed in a 600 kw microwave oven and heated for 1 minute 40 seconds. Then, the peeled state of the printed state in the food packaging bag after heating was visually evaluated in the following three stages.
○: No irregularities such as peeling and distortion are observed in the printed state of the food packaging bag.
Δ: Disturbances such as peeling and distortion are slightly observed in the printed state of the food packaging bag.
X: Disturbances such as peeling and distortion are observed in the printed state of the food packaging bag, and ink adhesion is observed in the microwave oven.

<Vapor escape>
Similar to “Printing ink peeling (dirt in the range)”, when the food packaging bag containing 100 g of broccoli and cooled is heated in a microwave oven, the portion other than the formation portion of the cutout (vapor hole) of the food packaging bag Whether or not steam was released from the product was visually evaluated in the following three stages.
○: No escape of steam is observed.
Δ: Slight escape of steam is observed.
X: The vapor | steam omission is recognized from several places other than a notch formation part.

<Vapor hole peeling state>
Similar to “printing ink peeling (dirt in the range)”, the food packaging bag containing 100 g of broccoli and cooled is heated in a microwave oven, and then the heat seal around the cutout (vapor hole) of the food packaging bag is peeled off. The state was visually evaluated in the following four stages.
(Double-circle): The heat seal around a notch has peeled off neatly.
○: A part not slightly peeled off is observed in the heat seal around the notch.
Δ: About half of the heat seal around the notch is not peeled off.
X: The heat seal around the notch is hardly peeled off.

<Anti-fogging property>
Using the films constituting the food storage bags obtained in the examples and comparative examples, antifogging properties were measured by the following procedure.
(1) Put 300 mL of hot water at 50 ° C. into a 500 mL upper opening container.
(2) The container opening is sealed with the film with the antifogging measurement surface of the film facing inside.
(3) Leave in a cold room at 5 ° C.
(4) After leaving in a cold room at 5 ° C. for 30 minutes, take it out of the cold room and evaluate the dew adhesion on the film measurement surface in 6 stages.
・ Evaluation Grade 6: No dew on the entire surface (zero adhesion area)
・ Evaluation grade 5: Slight dew adhesion (up to 1/5 of adhesion area)
・ Evaluation grade 4: Some dew adhesion (up to 1/4 adhesion area)
・ Evaluation 3rd class: About 1/2 dew adhesion (up to 2/4 adhesion area)
・ Evaluation 2nd class: Almost dew adhesion (up to 3/4 adhesion area)
・ Evaluation 1st grade: Dew adhesion on the entire surface

<Heat seal strength>
From the roll-like film (including the laminate film) used for forming the food storage bag in Examples and Comparative Examples, the length in the longitudinal direction = 500 mm × the length in the width direction (direction perpendicular to the longitudinal direction) = 50 mm A strip-shaped test piece having a size of 2 mm was cut out and folded in half along the width direction so that the heat-sealing layer was inside, thereby preparing a rectangular test piece having a size of 250 mm × 50 mm. Thereafter, heat sealing was performed using a thermal inclination tester (HG-100 5-point temperature level type manufactured by Toyo Seiki Co., Ltd.) at a pressure of 98 KPa and a predetermined temperature (130 ° C. and 140 ° C.) for 1 second. And after cutting the center part of the heat-sealed test piece into 15 mm width, the side sealed at low temperature between 20 mm distance chucks using “Tensilon” (STM-T-50BP) manufactured by Toyo Baldwin Co., Ltd. The test piece was gripped with the surface facing up and the strength when peeled at a speed of 200 mm / min (chart speed of 200 mm / min) was measured, and the measured value was defined as the heat seal strength (N / 15 mm).

Moreover, when producing food packaging bags in Examples and Comparative Examples, the following four types of synthetic resin films (polypropylene resin films) were used.
Film A: manufactured by Toyobo Co., Ltd. Antifoggant-containing stretched polypropylene resin (OPP) film P2161 (thickness = 25 μm)
Film B: manufactured by Toyobo Co., Ltd. Anti-fogging agent-containing stretched polypropylene resin (OPP) film P5562 (thickness = 25 μm)
Film C: Gunze Co., Ltd. Expanded polypropylene resin (OPP) film (non-fogging agent-free) SVS2 (thickness = 25 μm)
Film D: Toyobo Co., Ltd. anti-fogging agent-containing stretched polypropylene resin (OPP) film P5563 (thickness = 25 μm)
The characteristics of these films are shown in Table 1 below.

[Example 1]
Using the above-mentioned film D (roll shape with a constant width) and film B (roll shape with a constant width), a dry laminator made by Orient Sogyo Co., Ltd., an ether-based adhesive (Dick Dry LX401A: A laminate film having a thickness of about 50 μm was obtained by dry laminating at room temperature using a polyether polyurethane adhesive). When producing the laminate film, a predetermined ink (DIC Ink for Packaging (Univia NTK1: solvent type (non-toluene)) is used for printing on the surface of the film B (bonding surface with the film D). Then, the laminate film made up of the film D and the film B is continuously folded in two so that the film D is on the inside, and a sealing zipper is provided at the open edge. Further, heat-sealing is performed continuously, and a semi-circular heat seal having a diameter of about 12 mm is intermittently applied at a temperature of about 130 ° C. at a predetermined interval (about 150 mm interval) at the folding edge. A semicircular hole having a diameter of about 5 mm was drilled in the center of the portion, and then a straight line along the width direction of the film so that the semicircular hole was located in the center of the width direction. Then, a food storage bag of Example 1 was obtained by applying a fusing seal having a predetermined width (the width of the heat-sealed portion = about 0.3 mm) at a predetermined temperature (about 370 ° C.). The food storage bag of Example 1 was evaluated by the method described above, and the evaluation results are shown in Table 2 together with the characteristics of the food storage bag.

  An overview of the obtained food storage bag of Example 1 is shown in FIG. The food storage bag 1 is a three-sided bag having a size of width × height = 150 mm × 220 mm, and has a diameter of about 5 mm at the center (left and right center) of the rear edge (folding side edge). A semicircular cutout 2 is formed, and a heat seal portion 3 having a width of 0.3 mm is provided around the cutout 2. Further, a zipper made of synthetic resin (a type in which a long ridge is fitted in a long concave groove) 4 is fused to the opening, and can be sealed and opened.

[Example 2]
A laminate film was obtained by laminating the above-described film C (a roll having a constant width) and the film B in the same manner as in Example 1. After that, the laminate film composed of the film C and the film B is continuously folded in two so that the film C is on the inner side, and a zipper for sealing at the edge of the open end in the same manner as in Example 1. Is continuously heat-sealed, and a semicircular heat seal is intermittently applied to the edge of the folded edge at predetermined intervals, and a semicircular hole is drilled in the center of the heat seal portion, and then the predetermined temperature is reached. Then, a food storage bag of Example 2 was obtained by applying a fusing seal having a predetermined width. The food storage bag of Example 2 was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2 together with the characteristics of the food storage bag.

[Example 3]
A laminated film made of the film C and the film B obtained by the same method as in Example 2 was folded in half continuously so that the film C was inside, and the open end was formed in the same manner as in Example 1. A circular zipper with a diameter of approximately 12 mm at a temperature of approximately 130 ° C. at a predetermined interval (approximately 150 mm interval) at the center in the width direction of the film after continuously sealing a zipper for sealing at the edge. Sealing is performed intermittently, and a circular hole is drilled in the center of the heat seal portion, and then passes through the center of the circular hole and linearly extends along the width direction of the film. The food storage bag of Example 3 was obtained by performing a fusing seal with the width of the fusion part = about 0.3 mm. The food storage bag of Example 3 was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2 together with the characteristics of the food storage bag.

  Moreover, the general view of the food storage bag of Example 3 obtained is shown in FIG. Semicircular cutouts 2 and 2 having a diameter of about 5 mm are formed at the center of the left and right edges (the center in the height direction) of the food storage bag 11, respectively. Heat seal portions 3 and 3 having a width of 0.3 mm are provided around the periphery. Further, similarly to the food storage bag of the first embodiment, a synthetic resin zipper 4 is fused to the opening so that it can be sealed and opened.

[Example 4]
A laminated film made of the film C and the film B obtained by the same method as in Example 2 was continuously folded in half so that the film C was inside as in Example 1, and the edge of the open edge was A sealing zipper was continuously heat-sealed. Thereafter, a circular heat seal (first heat seal) having a diameter of about 12 mm is intermittently applied at a predetermined interval (about 150 mm interval), and the inner side of the circular first heat seal portion (the back side of the bag). Then, a heat seal (second heat seal) was applied to a rectangle having a length of 15 mm and a width of 5 mm so as to be inclined at an angle of about 45 ° with respect to the edge on the open side. Then, after making a circular hole at the center of the circular first heat seal portion, a predetermined width (thermal fusion) passes through the center of the circular hole and along the width direction of the film. The food storage bag of Example 4 was obtained by performing a fusing seal with a width of the portion (about 0.3 mm). Then, the food storage bag of Example 4 was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2 together with the characteristics of the food storage bag.

  In addition, an overview of the obtained food storage bag of Example 4 is shown in FIG. Semicircular cutouts 2 and 2 each having a diameter of about 5 mm are formed at the center (the center in the height direction) of the left and right edges of the food storage bag 21, respectively. The 1st heat seal part 3 and 3 of width 0.3mm is provided in the circumference | surroundings. Further, rectangular second heat seal portions 5 and 5 having a length of 15 mm and a width of 5 mm are provided on the inner side of the cutouts 2 and 2 (the back side of the bag). Inclined at an angle of 45 °. Each of the second heat seal portions 5 and 5 has the same length from both end edges to the center of the notch 2, and the length from the notch 2 to the nearest portion is about 10 mm. In addition, similar to the food storage bag of the first embodiment, a synthetic resin zipper 4 is fused to the opening so that it can be sealed and opened.

[Example 5]
A laminated film composed of the film C and the film B obtained by the same method as in Example 2 was continuously folded in half so that the film C was on the inner side, as in Example 2. A sealing zipper was continuously heat-sealed. Thereafter, a semi-circular heat seal (first heat seal) having a diameter of about 12 mm is intermittently applied to the folding edge at a predetermined interval (about 150 mm interval). A heat seal (second heat seal) was applied to the inner side (center side of the bag) in a rectangular shape having a length of 15 mm and a width of 5 mm so as to be inclined at an angle of about 45 ° with respect to the edge on the open side. Then, after making a semicircular hole having a diameter of about 5 mm in the center of the circular first heat seal portion, the semicircular hole was aligned along the width direction of the film so that the semicircular hole was located at the center in the width direction. A food storage bag of Example 5 was obtained by linearly sealing at a predetermined temperature (about 370 ° C.) with a predetermined width (heat fusion portion width = about 0.3 mm). The food storage bag of Example 5 was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2 together with the characteristics of the food storage bag.

  An overview of the obtained food storage bag of Example 5 is shown in FIG. A semicircular cutout 2 having a diameter of about 5 mm is formed at the center (left and right center) of the rear edge (folding side edge) of the food storage bag 31, and the periphery of the cutout 2. Is provided with a first heat seal portion 3 having a width of 0.3 mm. Further, a rectangular second heat seal portion 5 ′ having a length of 15 mm and a width of 5 mm is provided on the inner side (the back side of the bag) of the notch 2 so as to be substantially parallel to the edge on the opening side. . The second heat seal portion 5 has the same length from both end edges to the center of the notch 2 and the length from the notch 2 to the nearest portion is about 10 mm. In addition, similar to the food storage bag of the first embodiment, a synthetic resin zipper 4 is fused to the opening so that it can be sealed and opened.

[Comparative Example 1]
When forming a three-sided bag, printing is performed on the surface with a roll-shaped film C (DIC Corporation packaging ink (ULTIMA NT: gravure ink for solvent type (non-toluene) surface printing)) without using a laminate film. The food storage bag of Comparative Example 1 was obtained in the same manner as in Example 1 except that it was used alone. And the food storage bag of the comparative example 1 was evaluated by the same method as Example 1. The evaluation results are shown in Table 2 together with the characteristics of the food storage bag.

[Comparative Example 2]
A laminate film was obtained by laminating the above-described film C and film A (roll shape with a constant width) in the same manner as in Example 1. And the laminated film which consists of the obtained film C and the film A is folded in two continuously so that the film C may become an inner side, and it is the same method as Example 1, and is for sealing at the edge of an open end. The zipper was continuously heat sealed. Then, as in Example 1, a semicircular heat seal is intermittently applied to the folded edge at predetermined intervals, and a semicircular hole is drilled in the center of the heat seal portion, and then the predetermined temperature is reached. The food storage bag of Comparative Example 2 was obtained by applying a fusing seal with a predetermined width. And the food storage bag of the comparative example 2 was evaluated by the same method as Example 1. The evaluation results are shown in Table 2 together with the characteristics of the food storage bag.

  From Table 2, the food storage bags of Examples 1 to 4 exhibit good antifogging properties, and when the food storage bags are frozen using the food storage bags and then heated in a microwave oven, the printing ink may peel off. In addition, it can be seen that the notched portion can be exfoliated cleanly during heating and the saturated steam can be discharged, and no steam escapes from the portion other than the notched portion. On the other hand, the food storage bag of Comparative Example 1 that was not produced using a laminate film was susceptible to peeling of the printing ink, and one of the laminate films was not an anti-fogging film, and the elongation at break was 220%. It can be seen that in the food storage bag of Comparative Example 2 below this, the vapor hole portion is easily peeled off.

  Since the food storage bag of the present invention has excellent effects as described above, it can be suitably used as a food storage bag that can be heated in a microwave oven as it is after the food is stored and refrigerated / frozen. .

1, 11, 21, 31 ··· Food storage bag 2 · · Notch 3 · · Heat seal part (first heat seal part)
4. ・ Zipper 5,5 '・ ・ Heat seal part (second heat seal part)

Claims (3)

It is formed in a bag shape having an opening that can be released and sealed by a synthetic resin film, or an opening that can be sealed, and a notch is formed at least at one end of the edge, and the notch When the surroundings are heat-sealed and the internal pressure is raised in a sealed state, the heat-sealing around the notch is separated and the notch opens,
The synthetic resin film is an antifogging polypropylene resin film laminate formed by laminating a plurality of polypropylene resin films containing an antifogging agent,
A food storage bag, wherein the breaking elongation in the width direction of the bag made of the antifogging polypropylene resin film laminate is 220% or more and 250% or less. The food storage bag according to claim 1, wherein a second heat seal portion is provided closer to the opening than the heat seal portion around the notch.   The food storage bag according to claim 1 or 2, wherein the food storage bag is a rectangular three-sided bag, and is formed so that the cutouts are substantially symmetrical at the left and right ends.

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