pouch

Abstract

To provide a pouch which, when being heated in a microwave oven, can suppress tearing thereof and which enables vapor therein to be discharged stably therefrom.SOLUTION: A pouch 10 according to one embodiment of the present invention includes a packaging material. The packaging material comprises a first biaxially-oriented plastic film, a second biaxially-oriented plastic film, a third biaxially-oriented plastic film and a sealant film in this order. The sealant film comprises polypropylene as a main component. Only two biaxially-oriented plastic films are included in the packaging material. Breaking strength in one direction of the packaging material retained under an environment of 100°C for one minute and then measured under the environment of 100°C is 50.0 MPa or more. Seal strength of a sealing part 15 retained under an environment of 100°C for one minute and then measured under the environment of 100°C is 15.0 N or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pouch. [Background technology]

[0002] Conventionally, it has been possible to heat it in a microwave oven and store contents such as retort foods and frozen foods. Stand-up pouches that can be used for packaging are widely available. It is designed to stand on its own in the microwave and to withstand the heat generated by the microwave oven. The pouch is equipped with a steam release mechanism that automatically releases steam that accumulates in the pouch to the outside (for example, Patent Document 1 reference). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4029590 Summary of the Invention [Problem to be solved by the invention]

[0004] When such pouches are heated in a microwave oven, excessive pressure is applied, causing the steam release mechanism to fail. If steam cannot be released, the pouch may break, and even if it does not break, steam cannot be released. Sometimes parts other than the mechanism may open.

[0005] The present invention has been made to solve the above problems. The present invention aims to provide a pouch which is capable of suppressing breakage of the pouch and stably releasing steam. Let us assume that. [Means for solving the problem]

[0006] The present invention includes the following inventions. [1] A pouch including a packaging material and having a storage space, the packaging material comprising a first second a second biaxially oriented plastic film, a third biaxially oriented plastic film, and The first biaxially oriented plastic film and the sealant film are provided in this order, The plastic film is mainly composed of polyester, and the second biaxially oriented plastic The film is made of polyester or polyamide as a main component and is made of the second biaxially oriented plastic. When the main component of the film is polyester, the third biaxially oriented plastic film is The film is made of polyester or polyamide as the main component and is the second biaxially stretched film. In the case where the plastic film is mainly composed of polyamide, the third biaxially oriented plastic film is The sealant film is made of polypropylene. The main component is a biaxially oriented plastic film, and the packaging material contains only three sheets of biaxially oriented plastic film. The pouch is sealed by a sealing portion, and the sealing portion is adapted to be adapted to respond to an increase in pressure in the storage space. and a steam release seal configured to be easily peeled off, the pouch being The packaging material is configured so that steam can escape by peeling off the seal portion, and the packaging material is One-way fracture when measured in a 100°C environment after being held in a 100°C environment for 1 minute The strength is 50.0 MPa or more, and after being held in a 100°C environment for 1 minute, The pouch has a seal strength of 15.0 N or less when measured under the above-mentioned environmental conditions.

[0007] [2] The product of the tensile elongation (%) and the thickness (μm) of the sealant film in one direction is , more than 50,000. The pouch according to [1] above.

[0008] [3] Tensile elongation (%) and thickness of the sealant film in a direction perpendicular to the one direction The pouch according to [1] or [2] above, wherein the product of (μm) exceeds 55,000.

[0009] [4] The sealant film comprises a propylene-ethylene block copolymer and an elastomer. The pouch according to any one of [1] to [3] above, further comprising:

[0010] [5] The first biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film. film, and the second biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film. a biaxially oriented plastic film or a biaxially oriented nylon film, When the back film is the biaxially oriented polyethylene terephthalate film, The third biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film. or a biaxially oriented nylon film, and the second biaxially oriented plastic film is In the case of a biaxially oriented nylon film, the third biaxially oriented plastic film is Any one of [1] to [4] above, which is a biaxially oriented polyethylene terephthalate film. Item 3. A pouch as described in item 1.

[0011] [6] The packaging material comprises the first biaxially oriented plastic film and a second biaxially oriented plastic film. between the second biaxially oriented plastic film or between the third biaxially oriented plastic film The transparent deposition layer is formed between the plastic films. The pouch according to any one of [1] to [5] above, comprising an oxide or an inorganic oxide.

[0012] [7] The packaging material further comprises a transparent gas barrier coating film provided on the surface of the transparent deposition layer. The pouch according to [6] above.

[0013] [8] Any of the above [1] to [7], wherein the storage space of the pouch contains a content. 3. The pouch according to claim 1 . Effect of the Invention

[0014] According to one aspect of the present invention, the pouch can be prevented from breaking during heating in a microwave oven, and This provides a pouch that can stably release steam. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a front view of a pouch according to an embodiment. [Diagram 2] FIG. 2 is a diagram for explaining the dimensions of each component of the pouch shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view of the packaging material used for the pouch. [Figure 4] FIG. 4 is a diagram showing a test piece for measuring the hot breaking strength of a packaging material cut out from the front surface of a pouch. [Diagram 5] FIG. 5 is a diagram showing a test piece for measuring the hot breaking strength of a packaging material being cut out from the back surface of a pouch. [Figure 6] FIG. 6 is a diagram showing how the hot rupture strength is measured using a test piece. [Figure 7] FIG. 7 is a diagram showing a test piece for measuring the hot seal strength of a packaging material being cut out from a pouch. [Figure 8] FIG. 8 is a diagram showing how the hot seal strength is measured using a test piece. [Figure 9] FIG. 9 is a diagram illustrating hot seal strength (maximum tensile strength). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, a pouch according to an embodiment of the present invention will be described with reference to the drawings. In this document, the terms "film", "sheet", etc. are used interchangeably based solely on differences in designation. Therefore, for example, a "film" is also called a "sheet." FIG. 1 is a front view of a pouch according to an embodiment, and FIG. FIG. 3 is a diagram for explaining the dimensions of each component of the pouch shown in FIG. FIG. 4 is a cross-sectional view of a packaging material used in the present invention. Figure 5 shows the state of cutting a test piece from the front surface of the pouch for the purpose of the hot breaking of the packaging material. FIG. 6 shows the state when a test piece for measuring the breaking strength is cut out from the back of the pouch. FIG. 7 is a diagram showing how to measure the hot breaking strength of a test piece. FIG. 8 shows the state in which a test piece for measuring the strength of the test piece is cut out of the pouch. FIG. 9 is a diagram showing how the hot seal strength (maximum tensile strength) is measured using a FIG. 1 is a diagram illustrating the tensile strength.

[0017] <<<Pouch>>> The pouch 10 shown in FIG. 1 is a standing type pouch for containing contents. The container has a storage space 10A. The contents may be, but are not limited to, solids, liquids, or the like. Examples of the contents include curry, stew, soup, etc. Cooked foods include foods that have been sterilized by heat, such as boiling or retorting. In other words, the contents may contain heat-sterilized foods or pressurized heat-sterilized foods. "Retort processing" refers to the process of filling a pouch with the contents and sealing the pouch. After that, the pouch is heated under pressure using steam or heated water. The temperature of the treatment is, for example, 120° C. or higher. The pouch is in a state where no contents are filled. The concept is not limited to pouches, but also includes pouches filled with contents.

[0018] The pouch 10 shown in FIG. 1 comprises a front film 11, a back film 12 and a bottom film. The front film 11 and the back film 12 have a rectangular outline. In the state shown in FIG. 1, the bottom film 13 is folded in half. It is.

[0019] The pouch 10 has an upper portion 10B, a bottom portion 10C opposite the upper portion 10B, and a portion between the upper portion 10B and the bottom portion 10C. 0C. The second side 10E extends between the first side 10D and the second side 10E. is the side opposite to the first side portion 10D. The positions of the "side" and "bottom" refer to the positions of the pouch when it is standing upright.

[0020] The ratio of the height H1 (see FIG. 2) of the pouch 10 to the width W1 (see FIG. 2) of the pouch 10 (H It is preferable that H1 / W1 is 0.6 or more and 2.0 or less. If it is, it can hold more contents, and if H1 / W1 is 2.0 or less, it can hold In this state, the pouch 10 can stand stably. The lower edge of the pouch 10 in the Y direction DRY parallel to the direction in which the first side seal portion 16 extends. The length from 10G to the upper edge 10F of the pouch 10. If the length of the pouch is not constant, The pouch height is the largest value. The width W1 of the pouch 10 is perpendicular to the Y direction DRY. In the X-direction DRX, the pouch 10 is The length from the pouch width W1 to the side edge 10I of the pouch E. If the pouch width W1 is not constant, the pouch width is The shortest value is used. Dimensions of the pouch and components constituting the pouch in this embodiment All of the dimensions are measured with the pouch in a substantially flat state without expanding the gusset portion 14 described below. The value shall be determined as follows.

[0021] As shown in FIG. 1, the pouch 10 has a gusset portion 14 at the bottom portion 10C. By providing the container 14, it is possible to store larger contents or increase the capacity of the contents. This allows the pouch 10 to stand on its own.

[0022] As shown in FIG. 1, the pouch 10 includes a seal portion 15 for sealing the pouch 10. The seal portion 15 of the pouch 10 is a first side seal formed on the first side portion 10D. The second side seal portion 17 formed on the second side portion 10E and the first pleat portion 18 are formed on the second side portion 10E. The first bottom seal portion 20 is provided at the bottom 18, and the second bottom seal portion 20 is provided at the second pleat portion 19, which will be described later. The third bottom portion is provided on the side of the first pleat portion and the side of the second pleat portion. The seal portion 22 is configured to be peeled off by an increase in pressure in the storage space 10A of the pouch 10. In FIG. 1, the upper part of the pouch 10 is Although it is open, after the contents are filled into the storage space 10A, it is heat sealed to the upper part in FIG. The upper seal portion is formed in the upper seal portion planned region R surrounded by the edge 10F and the two-dot chain line, When the upper seal portion is formed, the width W4 of the upper seal portion (see FIG. 2) is ) is preferably, for example, 2 mm or more and 15 mm or less.

[0023] <First side seal portion and second side seal portion> The first side seal portion 16 is formed by sealing the front film 11 and the back film 12 at the first side portion 10D. The fold line 14A is formed at the top edge 10F. The second side seal portion 17 is formed by bonding the front film 11 and the back film 12 together at the second side portion 10E. The film 12 is joined to each other, and extends from the fold line 14A to the upper edge 10F of the pouch 10. When the first side seal portion 16 and the second side seal portion 17 are formed, The front film 11 and the back film 12 are joined by heat sealing (thermal fusion). It can be done.

[0024] The width W2 (see FIG. 2) of the first side seal portion 16 and the second side seal portion 17 is, for example, It is preferable that the first side seal portion 16 and the second side seal portion 17 are 2 mm or more and 15 mm or less, respectively. If the width W2 of the first side seal portion 17 and the width W3 of the second side seal portion 17 are each 2 mm or more, 6 and the second side seal portion 17 can be reliably sealed, and the gap is 15 mm or less. In this specification, each sheet The "width" of the seal portion means the length in the direction perpendicular to the direction in which the seal portion extends. In the case where the width of the seal portion is not constant, the width of the seal portion varies in a direction perpendicular to the direction in which the seal portion extends. The lower limit of the width W2 is preferably 4 mm or more. It is preferable that the upper limit is 10 mm or less.

[0025] The pouch 10 is located below the first side seal portion 16 and the second side seal portion 17. It has a first pleat portion 18 and a second pleat portion 19 .

[0026] <First pleat and second pleat> The first pleat portion 18 and the second pleat portion 19 are portions for forming the gusset portion 14. The first fold 18 is formed by folding the front film 11 and the front fold of the bottom film 13. The first part, which is the part on the room 11 side, is joined to the second part. The bottom film 13 is a part of the back film 12 and the bottom film 13 on the back film 12 side. The first pleat 18 is formed by joining the second part 18a to the first pleat 18b. The joining of the first portion of the front film 11 and the bottom film 13 at the time of the second fold portion 19 The joining of the back film 12 and the second portion of the bottom film 13 during the formation is performed by heat sealing. The first pleat portion 18 and the second pleat portion 19 are, for example, rectangular in shape. It may be so.

[0027] The height H2 of the first fold 18 relative to the height H1 of the pouch 10 in the Y direction DRY (see FIG. It is preferable that the ratio (H2 / H1) of the above H2 (see H2 / H1) is 0.1 or more and 0.5 or less. If / H1 is 0.1 or more, more contents can be stored. Also, if H2 / H1 is 0. If the value is 5 or less, the pouch 10 can be made to stand upright stably. The height H2 of the first pleat 18 is the length in the Y direction DRY. The length is from the first fold 14A to the lower edge 10G of the pouch 10. In this case, the height H2 of the first pleat 18 is set to the smallest value. The height of the pouch 10 in the Y direction DRY may be 0 mm or more and 50 mm or less. The ratio of the height of the second pleat portion 19 to H1 is also the same as H2 / H1.

[0028] The first fold portion 18 is a portion where the front film 11 and the bottom film 13 are joined together. The first bottom seal portion 20 is provided, and the second fold portion 19 is provided between the front film 11 and the bottom film 12. A second portion of the film 13 has a second bottom seal portion 21 joined thereto.

[0029] A part of the side of the first pleat portion 18 and a part of the side of the second pleat portion 19 are in contact with the front film 11. The sealant film 34 and the back film 12 of the packaging material 30 are described below. The third bottom sealant film 34 of the packaging material 30 is joined to the bottom sealant film 34. The third bottom seal portion 22 is joined by a sealant filler. The members 34 are joined together by heat sealing (thermal fusion).

[0030] The third bottom seal portion 22 is a part of the side of the first pleat portion 18 and a part of the side of the second pleat portion 19. The third bottom seal portion 22 is provided on the bottom film 13. The front film 11 and the back film 12 are joined together through the cutouts. In order to spread the bottom film when filling the content part into the storage space, the powder is At the center of the bottom of the chuck, the first pleat and the second pleat must be spaced apart. If the first pleat and the second pleat are completely separated, when the contents are filled into the storage space, the first pleat may be The fold and second fold cannot withstand the weight of the contents, and the gap between the first and second folds opens. In addition, the first biaxially oriented plastic Since films cannot be heat sealed together, the first biaxially oriented plastic film is The first and second pleats facing each other cannot be heat sealed as they are. Therefore, by forming the third bottom seal portion 22, the first pleat portion 18 and the second pleat portion 19 are This allows the bottom film 13 to be attached to both sides of the container when filling the container with contents. Therefore, the pouch 10 can be stably supported without being hindered from spreading.

[0031] As shown in FIG. 1, the first side seal 16 and the second side seal 17 have a seal The opening initiation means 23 is provided on the first side. It is sufficient that the sealing member is provided in either the first side seal portion 16 or the second side seal portion 17.

[0032] <<How to start opening>> The opening initiation means 23 can be a starting point for opening the pouch 10. The step 23 may be a cut or a notch. The opening initiation means 23 shown in FIG. It has a notch.

[0033] The first side portion 10D of the pouch 10 is heated by steam generated in the microwave oven. When the pressure inside the pouch 10 increases, a steam vent is provided to release the steam inside the pouch 10 to the outside. A mechanism 24 is provided.

[0034] <<Steam release mechanism>> The steam release mechanism 24 shown in FIG. 1 is not sealed and isolated from the storage space 10A. The first unsealed portion 25 is isolated from the storage space 10A and is on the first side. and a steam release seal portion 26 extending from the internal seal portion 16 toward the storage space 10A. is.

[0035] <First unsealed part> The first unsealed portion 25 reaches the side edges of the front film 11 and the back film 12. It has an opening 25A which serves as a steam port, and communicates with the outside via the opening 25A.

[0036] <Steam release seal> The steam release seal portion 26 is connected to the first side seal portion 16. The vent seal portion 26 is connected at one end to the upper portion 16A of the first side seal portion 16, and at the other end is connected to the lower portion 16B. As a result, the first unsealed portion 25 is The width W3 of the steam release seal portion 26 (see FIG. 2) is, for example, 2.5 mm or more. It is set to 6mm or less.

[0037] When the pressure inside the pouch 10 reaches a predetermined pressure due to heating, the steam release seal portion 26 As a result, the storage space 10A and the first unsealed portion 25 communicate with each other, and the storage space 10A and the first unsealed portion 25 communicate with each other. The steam in the container space 10A is automatically released to the outside of the pouch 10 through the first unsealed portion 25. In addition, the steam release seal portion 26 is closer to the storage space 10A side than the first side seal portion 16. Since the pouch 10 is protruding, when the pressure inside the pouch 10 increases due to heating in a microwave oven, Stress tends to concentrate on the steam release seal portion 26. In addition, the steam release seal portion 26 may peel off. Since the peeling easily progresses from the first side seal portion 16, etc., it is possible to suppress the peeling from progressing from the first side seal portion 16, etc. can.

[0038] The steam release mechanism 24 can release steam by peeling off the steam release seal portion 26. Any configuration that can achieve this is acceptable, and is not limited to the above example.

[0039] In addition, the pouch 10 has a second unsealed portion 27 formed in the second side sealed portion 17. This is because the first unsealed portion 25 is sealed to the front film 11 during the production of the pouch 10. 2 and is provided to ensure that an opening 25A is formed at the side edge of the back film 12. That is, the second unsealed portion 27 is provided to increase the manufacturing efficiency of the pouch 10. The second unsealed portion 27 is formed on the side edges of the front film 11 and the back film 12. The second unsealed portion 27 does not necessarily have to be provided. .

[0040] <<Packaging materials>> The front film 11 and the back film 12 are made of a packaging material 30 shown in FIG. The bottom film 13 is made of a packaging material 30 shown in FIG. The packaging material 30 includes at least a first biaxially oriented plastic film 31 and , a second biaxially oriented plastic film 32, and a third biaxially oriented plastic film 3 The packaging material 30 includes a packaging material 30 and a sealant film 34 in this order. The sealant film 34 has only three biaxially oriented plastic films. This is the layer that constitutes the inner surface of the pouch 10. The packaging material 30 shown in FIG. Biaxially oriented plastic film 31, printing layer 35, first adhesive layer 36, second biaxially oriented plastic plastic film 32, second adhesive layer 37, third biaxially oriented plastic film 33 , a third adhesive layer 38, and a sealant film 34 in this order. The material is disposed between the first biaxially oriented plastic film 31 and the sealant film 34. The pouch 1 may further include a functional layer that exhibits a desired function, such as a transparent gas barrier layer. The packaging material 30 can be produced by continuously transporting the packaging material 30 wound in a roll. do.

[0041] The packaging material 30 was held in a 100°C environment for 1 minute and then measured in a 100°C environment. The unidirectional breaking strength (hot breaking strength) when the material is packed is 50.0 MPa or more. The hot rupture strength in one direction of the material 30 is preferably 51.0 MPa or more. More preferably, the elastic modulus is 53.0 MPa or more, and even more preferably, the elastic modulus is 56.0 MPa or more. The hot breaking strength of the packaging material 30 in the direction perpendicular to the one direction is 46. It is preferable that the pressure is 50.0 MPa or more, and more preferably 50.0 MPa or more. It is more preferable that the pressure is 3.0 MPa or more, and most preferable that the pressure is 54.0 MPa or more. One direction of the packaging material 30 is, for example, the X-direction DRX (see FIG. 1 ) of the pouch 10. ) and the direction perpendicular to one direction of the packaging material 30 is, for example, the Y direction of the pouch 10. For example, the machine direction (MD) of the packaging material 30 may be the same as that of the pouch 10. For example, the width direction (TD) of the packaging material 30 corresponds to the Y direction (D For example, one direction of the packaging material 30 may correspond to the machine direction (MD). For example, the direction perpendicular to one direction of the packaging material may be the transverse direction (TD). stomach.

[0042] The hot breaking strength of the packaging material 30 was measured with respect to the length of the test pieces S1 and S2 described later. The filling shall be performed in accordance with JIS K7127. First, fill the front surface of the pouch 10. From the room 11, excluding the seal portion 15, one side L1 (see FIG. 4) is 15 mm. A rectangular test piece with one side L1 and the other side L2 (see Figure 4) extending perpendicularly to it being 100 mm long The other side L2 of the test piece S1 is in the X-direction DRX (first side section). The pouch is then cut out so that it is parallel to the direction perpendicular to the extension direction of the roll portion 16. 10 from the back surface film 12 so as not to include the seal portion 15, one side L1 (see FIG. 5 ) is 15 mm, and the other side L2 (see Figure 5) extending in a direction perpendicular to the side L1 is 100 mm long. Five rectangular test pieces S2 (see FIG. 5) are cut out. The other side L2 of the test piece S2 is in the Y direction DR. The cut is made parallel to Y (the direction parallel to the extension of the first side seal portion 16). The Tensilon universal material testing machine RTC-1310A (manufactured by A&D Co., Ltd.) The hot rupture strength of the test piece S1 is measured using the following. As shown in FIG. 6, the test piece S1 is held at both ends in the longitudinal direction by the holding devices 51 and 52. The layer structure of the test pieces S1 and S2 is partially omitted. After holding the test piece S1 in this environment for 1 minute, it was placed in an environment with a temperature of 100°C and a relative humidity of 5%. With the initial gripping distance D1 (see Figure 6) set to 50 mm, the tension speed was 300 mm / min. A tensile test was performed by pulling the test piece S1 in the longitudinal direction of the test piece S1, and the hot rupture strength of the test piece S1 was The hot rupture strength of the test piece S2 is also measured under the same measurement conditions as the test piece S1. The hot breaking strength of the five test pieces S1 was measured, and the average value was calculated as the packing material 3. The hot fracture strength in the X direction DRX of 0 is taken as the hot fracture strength. In addition, the hot fracture strength of five test pieces S2 is The average value is taken as the hot breaking strength of the packaging material 30 in the Y direction DRY.

[0043] The packaging material 30 was held in a 100°C environment for 1 minute and then measured in a 100°C environment. The seal strength (hot seal strength) at this time is 15.0N or less. Hot seal strength is preferably 12.0 N or less, and more preferably 10.0 N or less. Also, if the hot seal strength is too low, the contents may steam before they are sufficiently heated and pressurized. The vent seal portion 26 may peel off, causing a decrease in pressure and temperature in the storage space 10A. Considering this point, the hot seal strength of the seal portion 15 of the pouch 10 is preferably The pressure is preferably 4N or more, and more preferably 5N or more. The seal strength of the steam release seal 26 may also change depending on the treatment, but the pouch 10 may be retorted. When a soldering process is applied, unless otherwise specified, the "sealing strength of the seal part" refers to the soldering strength of the This refers to the seal strength of the sealed part of the pouch after the melting treatment has been applied.

[0044] In measuring the hot seal strength of the packaging material 30, first, one pouch is prepared. The front filter includes a first side seal portion 16 or a second side seal portion 17. When the film 11 and the back film 12 are joined together, one side L3 (see FIG. 7) is 15 mm, and one side L The other side L4 (see Figure 7) extending in a direction perpendicular to the test piece S3 (see Figure 7) is a rectangular test piece S3 (see Figure 7). For example, as shown in FIG. 7, cut out five pieces of the first side seal portion 16. Three test pieces S3 are cut out so as to include the second side seal portion 17. The test pieces S3 are The other side L4 is parallel to the X-direction DRX (the direction perpendicular to the direction in which the first side seal portion 16 extends). and not including the steam release seal portion 26. Three pieces are cut out from the side of the second side seal portion 17 and two pieces are cut out from the side of the second side seal portion 17. Measure the hot seal strength. The hot seal strength is based on JIS Z1707:1997 7.5. Compliant with Tensilon universal material testing machine RTC-1310A (manufactured by A&D Co., Ltd.) First, the two sheets of packaging material 30 in the unsealed portion of the test piece S3 are The test pieces are held by the holding tools 53 and 54 (see FIG. 8) of the tester. , the layer structure of the test piece S3 is partially omitted. In the direction perpendicular to the surface direction of the seal part of one S3, The specimen is pulled at a speed of 1 / min and the maximum tensile stress is measured. The average of the maximum values ​​is then taken as the seal strength. (See Figure 9.) The hot seal strength was measured by placing the test piece S3 at a temperature of 100°C and a relative humidity of After holding for 1 minute in an environment of 100°C and 5% relative humidity, the test was performed in an environment of 5% relative humidity. The hot seal strength of the test piece S3 is measured, and the average value is regarded as the hot seal strength of the pouch. do.

[0045] <Biaxially oriented plastic film> Biaxially oriented plastic film is a plastic film that is stretched in order to improve its mechanical strength. In the present invention, the biaxial stretching is performed intentionally on the plastic film. A stretched plastic film is one that meets at least one of the following criteria: (a) or (b) It refers to something that fulfills. (a) Young's modulus is 1000 MPa or more in one direction and in a direction perpendicular to the one direction (b) Tensile elongation is 200% or less in one direction and in a direction perpendicular to the one direction.

[0046] The Young's modulus and tensile elongation of biaxially oriented plastic film are measured according to JIS K712 7. First, a biaxially oriented plastic film is cut into pieces with a length of 15 mm. A rectangular test piece with one side extending perpendicular to the other side and 150 mm long was cut out. The test piece is kept in an environment of 25°C for 24 hours. Then, it is tested with the Tensilon universal material testing machine RTC- 1310A (manufactured by A&D Co., Ltd.) at a temperature of 25°C and a relative humidity of 50%. The Young's modulus and tensile elongation of the test specimen are measured under the environment. The initial gripping distance is 100m. The test was performed with the initial gripping distance of 100 mm. The length in the direction perpendicular to one side can be adjusted as far as possible.

[0047] (First biaxially stretched plastic film) The first biaxially stretched plastic film 31 is a plastic film stretched in two predetermined directions. The first biaxially oriented plastic film 31 is a packaging material 30. It functions as a base film to give the film a certain strength. The stretching direction of the film 31 is not particularly limited. For example, the first biaxially stretched plastic film The film 31 is stretched in the direction in which the side edge 10H extends and in a direction perpendicular to this direction. The stretching ratio of the first biaxially stretched plastic film 31 may be, for example, 1.0 More than five times as much.

[0048] The first biaxially oriented plastic film 31 contains polyester as a main component. In the fine print, "containing polyester as the main component" means biaxially oriented plastic film. It means that the polyester content is more than 50% by mass. Examples of polyester include: Polyethylene terephthalate (hereinafter referred to as PET), polybutylene terephthalate ( Hereinafter, the first biaxially oriented plastic may be referred to as PBT. More than 50% by mass of the polyester in the film 31 is made of one type of polyester. It may be composed of one or more kinds of polyester. As the first biaxially oriented plastic film, a biaxially oriented PET film can be used. The biaxially stretched PET film preferably contains 80% by mass or more of PET. The biaxially stretched PET film preferably contains 90% by mass or more of PET, and more preferably 95% by mass or more of PET. It is even more preferable that the above is included.

[0049] The thickness of the first biaxially stretched plastic film 31 is preferably 8 μm or more. More preferably, the thickness is 9 μm or more, and further preferably, the thickness is 12 μm or more. The thickness of the first biaxially stretched plastic film 31 is preferably 30 μm or less, and The thickness of the first biaxially stretched plastic film 31 is preferably 8 μm or less. By making the thickness of the first biaxially stretched plastic film 31 to be 1 / 2 inch (m) or more, the first biaxially stretched plastic film 31 has sufficient strength. In addition, the thickness of the first biaxially stretched plastic film 31 is set to 30 μm or less. By doing so, the first biaxially stretched plastic film 31 exhibits excellent formability. Therefore, the process of processing the packaging material 30 to manufacture the pouch 10 can be carried out efficiently. It is possible.

[0050] (Second biaxially oriented plastic film) The second biaxially oriented plastic film 32 is, for example, Like the film 31, it is a base film stretched in two predetermined directions. For example, The second biaxially stretched plastic film 32 is aligned in the direction in which the side edge 10H extends and in this direction. The second biaxially oriented plastic film 3 may be stretched in a direction perpendicular to the first biaxially oriented plastic film 3. The second biaxially oriented plastic film 2 also provides a predetermined strength to the packaging material 30, similar to the first biaxially oriented plastic film 31. The second biaxially oriented plastic film 32 functions as a base film to hold the film in place. The stretching direction of the first biaxially stretched plastic film 31 is not particularly limited, as in the case of the first biaxially stretched plastic film 31. do not have.

[0051] The second biaxially oriented plastic film 32 is a biaxially oriented plastic film containing polyamide as a main component. Plastic film or biaxially oriented plastic containing polyester as the main component In the present specification, the term "containing polyamide as a main component" means a biaxial This means that the oriented plastic film contains more than 50% by weight of polyamide. Examples of amides include aliphatic or aromatic polyamides. Aliphatic polyamides include nylon-6, nylon-6,6, nylon 6 and nylon 6 Examples of aromatic polyamides include polymethylene glycol, ethylene glycol copolymers, and nylon copolymers. Lenadipamide (MXD6) and the like. Second biaxially oriented plastic film 3 Since the second biaxially oriented plastic film 3 contains polyamide as a main component, The puncture strength of the packaging material 30 containing polyester 2 can be increased. Examples of the polyester include those listed in the column for the first biaxially oriented plastic film 31. The second biaxially oriented plastic film 32 may be a biaxially oriented nylon film or a biaxially oriented A stretched polyethylene terephthalate film can be used. A biaxially stretched nylon film can be used. The film preferably contains 80% by mass or more of polyamide. The film preferably contains 90% by mass or more of polyamide, and more preferably 95% by mass or more of polyamide. Even more preferred.

[0052] The second biaxially oriented plastic film 32 is a film containing polyester as a main component. When a biaxially stretched plastic film is used, the thickness of the second biaxially stretched plastic film 32 is The thickness of the second biaxially oriented plastic film 31 can be the same as that of the second biaxially oriented plastic film 32. When a film containing polyamide as a main component is used as the backing film 32, the second The thickness of the biaxially stretched plastic film 32 is preferably 12 μm or more, and more preferably The thickness of the second biaxially stretched plastic film 32 is preferably 15 μm or more. It is preferably 30 μm or less, and more preferably 25 μm or less.

[0053] The second biaxially oriented plastic film 32 has tearability in the machine direction (MD). In the following description, the pull in the machine direction (MD) A biaxially oriented plastic film that has tearability is called a biaxially oriented straight cut film. By using biaxially stretched straight cut film, the machine direction (MD) The packaging material 30 can be provided with tearability. The tensile strength of the straight cut film is the same as that of the biaxially stretched straight cut film in the cross direction (TD). Tensile strength of biaxially stretched straight cut film in machine direction (MD) is greater than that of The strength is the tensile strength of the biaxially stretched straight cut film in the transverse direction (TD), preferably It is 1.05 times or more, more preferably 1.10 times or more, and even more preferably 1.20 times or more. The tensile strength of the biaxially stretched straight cut film in the machine direction (MD) is more than twice as high. is, for example, 200 MPa or more and 300 MPa or less.

[0054] (Third biaxially oriented plastic film) The third biaxially oriented plastic film 33 is, for example, Like the film 31, it is a base film stretched in two predetermined directions. For example, The third biaxially stretched plastic film 33 is aligned in the direction in which the side edge 10H extends and in this direction. The third biaxially stretched plastic film 3 may be stretched in a direction perpendicular to the first biaxially stretched plastic film 3. The first biaxially oriented plastic film 31 also has the function of providing a predetermined strength to the packaging material 30. The third biaxially oriented plastic film 33 functions as a base film to hold the film in place. The stretching direction of the first biaxially stretched plastic film 31 is not particularly limited, as in the case of the first biaxially stretched plastic film 31. do not have.

[0055] When the second biaxially oriented plastic film 32 is mainly composed of polyester, The third biaxially oriented plastic film 33 is made mainly of polyester or polyamide. However, when the second biaxially stretched plastic film 32 is mainly composed of polyamide, The third biaxially stretched plastic film 33 is mainly composed of polyester. Since the stretched plastic film 33 contains polyamide as a main component, the third biaxial The puncture strength of the packaging material 30 including the stretched plastic film 33 can be increased. do.

[0056] The thickness of the third biaxially oriented plastic film 33 is equal to that of the second biaxially oriented plastic film. Since the thickness of the film 32 is the same as that of the film 32, it is omitted here. The plastic film 33 may be a biaxially stretched straight cut film as described above.

[0057] <Sealant film> Next, the sealant film 34 will be described. The sealant film 34 is a single layer. The sealant film 34 is preferably unstretched. The term "unstretched" does not only refer to films that are not stretched at all. This concept also includes a film that is slightly stretched due to the tension applied during film formation. do.

[0058] A sealant film is one that satisfies at least one of the following (c) or (d): It refers to something that is (c) Young's modulus is less than 1000 MPa in one direction and in a direction perpendicular to the one direction. (d) Tensile elongation of 300% or more in one direction and in a direction perpendicular to the one direction

[0059] The Young's modulus and tensile elongation of the sealant film are measured in accordance with JIS K7127. First, one side is 15 mm from the sealant film, and the other side is perpendicular to the direction. A rectangular test piece with the other side extending to the left and the other side extending to the right was cut out and placed in an environment of 25°C. The specimen was then held at this temperature for 24 hours. Then, a Tensilon universal material testing machine RTC-1310A (Corporate A&D (manufactured by A&D) was used to measure the temperature of the test specimens at 25°C and a relative humidity of 50%. The initial gripping distance was 100 mm, and the tensile speed was 300 m. m / min. Note that the initial gripping distance is set to 100 mm, and as far as possible, In this case, the length in the direction perpendicular to one side is adjustable.

[0060] The pouch 10 made of the packaging material 30 is subjected to a sterilization process such as a retort process at high temperatures. Therefore, the sealant film 34 has a heat resistance that can withstand these high temperature processes. The one having the following formula is used.

[0061] The melting point of the material constituting the sealant film 34 is preferably 150° C. or higher. It is more preferable that the melting point of the sealant film 34 is 160° C. or higher. This allows the pouch 10 to be retorted at high temperatures, and thus The time required for the tortuos process can be shortened. The melting points of the materials to be used are the first biaxially oriented plastic film 31 and the second biaxially oriented plastic film 32. The melting points of the resins constituting the plastic film 32 and the third biaxially oriented plastic film 33 Lower.

[0062] The sealant film 34 contains polypropylene as a main component. "Contains polypropylene as the main component" means that the sealant film contains more than 50% polypropylene by mass. The term "propylene" refers to a material that contains propylene as a main component. propylene-ethylene block copolymer, propylene-ethylene random copolymer, Polypropylene such as homopolypropylene, or a mixture of polypropylene and polyethylene Examples of the propylene-ethylene block copolymer include " refers to a material having the structural formula shown in the following formula (1). "Ethylene random copolymer" means a material having the structural formula shown in the following formula (2). In addition, "homopolypropylene" refers to a material having the structural formula shown in the following formula (3): It means.

[0063] [ka] In the above formula (1), m1, m2, and m3 represent integers of 1 or more.

[0064] [ka] In the above formula (2), m and n represent integers of 1 or more.

[0065] [ka] In the above formula (3), m represents an integer of 1 or more.

[0066] A material mainly composed of propylene, which is a mixture of polypropylene and polyethylene. When using the above, the material may have an island-in-a-sea structure. Here, the term "island-in-a-sea structure" means A structure in which polyethylene is discontinuously dispersed within a continuous polypropylene region. cormorant.

[0067] Preferably, the sealant film 34 contains a propylene-ethylene block copolymer. For example, the sealant film 34 is a single-layer film made of propylene-ethylene It is a single-layer unstretched film whose main component is a propylene-ethylene block copolymer. By using the copolymer, the impact resistance of the sealant film 34 can be increased. This can prevent the pouch 10 from being broken due to the impact of being dropped. In addition, the puncture resistance of the packaging material 30 can be improved.

[0068] In addition, by using a propylene-ethylene block copolymer, the The strength of the seal portion formed by the sealant film 34 at 00° C., i.e. The above-mentioned hot seal strength is extremely small compared to the seal strength at low temperatures, for example, at room temperature. Due to the low inter-seal strength, when the pouch 10 is heated in a microwave oven, steam escape is difficult. The seal portion 26 becomes easier to peel off, and steam in the storage space 10A easily escapes to the outside of the pouch 10. Therefore, the internal pressure of the accommodation space 10A can be prevented from becoming excessive. This can prevent damage to the packaging material 30 when heated.

[0069] Propylene-ethylene block copolymers, for example, have a sea component made of polypropylene and The sea component is made of propylene and the island component is made of ethylene-propylene copolymer rubber. The blocking resistance, heat resistance, rigidity, and seal strength of the ethylene block copolymer are improved. In addition, the island component can contribute to the impact resistance of the propylene-ethylene block copolymer. Therefore, by adjusting the ratio of sea component to island component, Tailoring the mechanical properties of sealant films containing propylene-ethylene block copolymers It is possible.

[0070] In propylene-ethylene block copolymers, the quality of the sea component made of polypropylene The mass ratio of the island component made of the ethylene-propylene copolymer rubber component is higher than the mass ratio of the island component made of the ethylene-propylene copolymer rubber component. For example, in the case of propylene-ethylene block copolymers, The mass ratio of the component is at least 51% by mass or more, preferably 60% by mass or more, More preferably, it is 70% by mass or more.

[0071] The single-layer sealant film 34 is a first layer made of a propylene-ethylene block copolymer. In addition to the first thermoplastic resin, the second thermoplastic resin is further included. Examples of the α-olefin copolymer include α-olefin copolymer and polyethylene. The copolymer is, for example, linear low density polyethylene. Examples of polyethylene include high density polyethylene, medium density polyethylene, and high density polyethylene. The thermoplastic resin can contribute to increasing the impact resistance of the sealant film 34. By using the second thermoplastic resin, the above-mentioned hot seal strength can be improved at low temperatures, for example, at normal temperatures. It can be made even smaller than the hot seal strength.

[0072] Low density polyethylene has a density of 0.910g / cm 3 More than 0.925g / cm 3 below Medium density polyethylene has a density of 0.926 g / cm 3 More than 0.9 40g / cm 3 High density polyethylene is polyethylene with a density of 0.941 g / cm 3 More than 0.965g / cm 3 The following polyethylenes are available: Low density polyethylene For example, it is obtained by polymerizing ethylene at a high pressure of 1000 to 2000 atmospheres. Medium density polyethylene and high density polyethylene can be, for example, compressed at pressures of 1 atm to 1000 atm. It is obtained by polymerizing ethylene at medium or low pressure below 1000MPa.

[0073] Medium density polyethylene and high density polyethylene are made from ethylene and α-olefins. In addition, when ethylene is polymerized at a medium or low pressure, However, if it contains a copolymer of ethylene and α-olefin, it is not considered to be medium or low density polyethylene. Such polyethylene can be produced by the linear low density polyethylene described above. Linear low-density polyethylene is produced by polymerizing ethylene at medium or low pressure. By copolymerizing α-olefins with the linear polymer obtained by Examples of α-olefins are 1-butene (C4), 1-hexene (C 6), 4-methylpentene (C6), and 1-octene (C8). The density of linear low density polyethylene is, for example, 0.915 g / cm 3 More than 0.945g / c m 3 The following is the result.

[0074] In addition, the α-olefin that constitutes the second thermoplastic resin of the propylene-ethylene block copolymer The olefin copolymer is not limited to the linear low density polyethylene described above. The copolymer means a material having the structural formula shown in formula (4) below.

[0075] [ka] R 1 , R 2 Each of these is H (hydrogen atom) or an alkyl group such as CH3 or C2H5. In addition, j and k are both integers equal to or greater than 1. In addition, j is greater than k. That is, in the α-olefin copolymer shown in formula (4), R 1 The structure on the left, which contains It serves as the base. 1 For example, H and R 2 For example, C2H5.

[0076] In the sealant film 34, the first layer is made of a propylene-ethylene block copolymer. The mass ratio of the thermoplastic resin in 1 is at least α-olefin copolymer or polyethylene. The mass ratio of the second thermoplastic resin is higher than that of the first thermoplastic resin. wherein the mass ratio of the first thermoplastic resin is a propylene-ethylene block copolymer. The ratio is at least 51% by mass or more, preferably 60% by mass or more, and more preferably In most cases, it is 70 mass % or more.

[0077] As described above, the second thermoplastic resin increases the impact resistance of the sealant film 34. Therefore, the α-olefin copolymer in the single-layer sealant film 34 may contribute to the above-mentioned problems. By adjusting the mass ratio of the second thermoplastic resin containing at least polyethylene or This makes it possible to adjust the mechanical properties of the sealant film 34.

[0078] The sealant film 34 further contains an elastomer such as a thermoplastic elastomer. By using a thermoplastic elastomer, the durability of the sealant film 34 can be improved. It is possible to further improve impact resistance and puncture resistance. In addition, the use of thermoplastic elastomers As a result, the above-mentioned hot seal strength is further reduced compared to the seal strength at low temperatures, for example, at room temperature. It can be reduced.

[0079] The thermoplastic elastomer is, for example, a hydrogenated styrene-based thermoplastic elastomer. The ethylene-based thermoplastic elastomer is a polymer having at least one vinyl aromatic compound as a main component. A polymer based on a polymer block A and at least one hydrogenated conjugated diene compound. The thermoplastic elastomer has a structure consisting of ethylene-α-olefin block B. The ethylene-α-olefin elastomer may be a low crystallinity elastomer. It is a crystalline or amorphous copolymer elastomer, and the main component is 50 to 90 mass % elastomer. It is a random copolymer of ethylene and an α-olefin as a copolymerization monomer.

[0080] The content of propylene-ethylene block copolymer in sealant film 34 is For example, it is 80% by mass or more, and preferably 90% by mass or more.

[0081] The method for producing propylene-ethylene block copolymers is to use a catalyst as the raw material. The polymerization of propylene and ethylene is one example. The catalyst is Ziegler. Natta type or metallocene catalysts can be used.

[0082] The thickness of the sealant film 34 is preferably 30 μm or more, and more preferably 4 The thickness of the sealant film 34 is preferably 100 μm or less. and more preferably 80 μm or less.

[0083] As a single layer sealant film containing a propylene-ethylene block copolymer, There are types such as the ZK500 described below that have high tensile elongation and impact resistance. This type of sealant film 34 preferably has the property of low hot seal strength. This prevents the internal pressure of the storage space 10A from becoming excessive when the pouch 10 is heated. It is possible to suppress the above.

[0084] Sealant film 34 in the machine direction (MD) was left in a 25°C environment for 24 hours. The tensile elongation (%) measured in an environment of 25°C after drying is preferably 800% or more. More preferably, it is 900% or more, and may be 1000% or more, or 1100% or more. In addition, the tensile elongation (%) of the sealant film 34 in the machine direction (MD) and the sealant The thickness (μm) product of the support film 34 is preferably greater than 50,000, more preferably It may be 55,000 or more, or 60,000 or more.

[0085] The sealant film 34 in the transverse direction (TD) was kept in a 25°C environment for 24 hours. The tensile elongation measured in an environment of 25° C. after the heating is preferably 1050% or more, and more preferably The tensile strength of the sealant film in the transverse direction (TD) is 1100% or less. The product of elongation (%) and thickness (μm) of the sealant film is preferably greater than 55,000; More preferably, it is 60,000 or more. The sealant film 34 has a high tensile elongation. This makes it possible to prevent the pouch 10 from being torn due to an impact such as when it is dropped. can.

[0086] Sealant film 34 in the machine direction (MD) was left in a 25°C environment for 24 hours. The tensile modulus measured in an environment of 25°C after drying is preferably 670 MPa or less. More preferably, the sealant filler in the machine direction (MD) is 650 MPa or less. The product of the tensile modulus (MPa) of the sealant film 34 and the thickness (μm) of the sealant film 34 is preferably It is preferably less than 35,000, and more preferably 34,000 or less.

[0087] The sealant film 34 in the transverse direction (TD) was kept in a 25°C environment for 24 hours. The tensile modulus measured in an environment of 25°C after heating is preferably 550 MPa or less, and more preferably 550 MPa or less. The strength of the sealant film in the transverse direction (TD) is preferably 500 MPa or less. The product of the tensile modulus (MPa) of the sealant film 34 and the thickness (μm) of the sealant film 34 is preferably is less than 28,000, more preferably 25,000 or less.

[0088] The tensile modulus of the sealant film 34 is similar to the tensile elongation of the sealant film 34. The measurement shall be performed using the same measurement method and under similar measurement conditions.

[0089] <Print layer> The printing layer 35 provides information about the contents or the packaged product, or provides an aesthetic appearance to the pouch. The printing layer 35 is a layer for attaching the printed material to the substrate and contains, for example, a coloring material and a binder resin. By this, a pattern can be formed on the pouch 10. In this specification, the term "pattern" means , but is not limited to, and broadly includes, for example, figures, letters, designs, patterns, symbols, patterns, marks, etc. The ink used for gravure printing is Finart manufactured by DIC Graphics Corporation. There can be.

[0090] The printing layer 35 may further contain any additives. Examples of the additives include: Lubricants, anti-blocking agents, fillers, hardeners, pigment dispersants, defoamers, leveling agents, waxes Silane coupling agents, preservatives, antioxidants, UV absorbers, rust inhibitors, plasticizers, These additives are used to improve printability and printing effect. The type and amount of each agent used can be selected according to the printing method, printing substrate, and printing conditions. The printing layer 35 is formed on the first biaxially oriented plastic film 31 by a printing method such as gravure printing. It can be formed by:

[0091] (Colorant) The coloring material is not particularly limited, and known pigments and dyes can be used according to the desired color. Choose appropriately.

[0092] (binder resin) Examples of binder resins include linseed oil, tung oil, soybean oil, hydrocarbon oil, rosin, and rosin. resin, rosin-modified resin, shellac, alkyd resin, phenolic resin, maleic acid resin, vinyl chloride resin, polyacetate resin, natural resin, hydrocarbon resin, polyvinyl chloride resin, polyacetate resin, Styrene-based resin, polyvinyl butyral resin, (meth)acrylic resin, polyamide resin , polyester resin, polyurethane resin, epoxy resin, urea resin, melamine resin , aminoalkyd resin, nitrocellulose, ethylcellulose, chlorinated rubber, cyclized rubber , a polymer of a (meth)acrylate compound, or a mixture thereof.

[0093] <First adhesive layer to third adhesive layer> The first adhesive layer 36 is formed by bonding the first biaxially oriented plastic film 31 and the second biaxially oriented plastic film 32 together. The adhesive agent is used to bond the adhesive film 32 to the adhesive film 32 by a dry lamination method. The adhesive layer 37 is disposed between the second biaxially oriented plastic film 32 and the third biaxially oriented plastic film 33. The third adhesive includes an adhesive for bonding the film 33 to the film 33 by a dry lamination method. The layer 38 is a drape made of the third biaxially oriented plastic film 33 and the sealant film 34. Includes adhesives for bonding by lamination method.

[0094] The adhesives constituting the first adhesive layer 36, the second adhesive layer 37, and the third adhesive layer 38 are The first composition containing a base agent and a solvent is mixed with a second composition containing a hardener and a solvent. Specifically, the adhesive is produced by dissolving the main agent in the adhesive composition. This includes a cured product produced by reaction with a curing agent.

[0095] An example of an adhesive is polyurethane. Polyurethane is a base material. It is produced by reacting a polyol as a polymer with an isocyanate compound as a curing agent. Polyurethane is a hardened product of polyol and isocyanate compounds. Examples of the polyurethane include polyether polyurethane and polyester polyurethane. Polyether polyurethane is made of polyether polyol as the base agent and It is a cured product produced by reacting with an isocyanate compound. Urethane is made of polyester polyol as the base material and isocyanate as the hardener. It is a cured product produced by reacting with a compound.

[0096] Isocyanate compounds include tolylene diisocyanate (TDI), 4,4'-diisocyanate, Phenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), etc. Any aromatic isocyanate compound, hexamethylene diisocyanate (HDI), isocyanate, Aliphatic isocyanate compounds such as phenyl diisocyanate (IPDI), or Adducts or oligomers of the above various isocyanate compounds can be used.

[0097] The thicknesses of the first adhesive layer 36, the second adhesive layer 37, and the third adhesive layer 38 are preferably The thickness is preferably 2 μm or more, and more preferably 3 μm or more. The thickness of the second adhesive layer 37 and the third adhesive layer 38 is preferably 6 μm or less, More preferably, it is 5 μm or less.

[0098] As described above, the isocyanate compound constituting the curing agent of the adhesive is There are aromatic isocyanate compounds and aliphatic isocyanate compounds. Aromatic isocyanate compounds are used in food applications under high temperature environments such as heat sterilization. The third adhesive layer 38 is bonded to the sealant film 34. Therefore, when the third adhesive layer 38 contains an aromatic isocyanate compound, The components eluted from the aromatic isocyanate compound are absorbed by the sealant film 34. In consideration of such a problem, Preferably, the adhesive constituting the third adhesive layer 38 is a polyol as a base agent and a hardener. The cured product is produced by reacting with an aliphatic isocyanate compound as a curing agent. This allows the components that cannot be used for food applications, which are caused by the third adhesive layer 38, to be removed from the This can prevent the liquid from adhering to the container.

[0099] <Gas barrier film> First biaxially stretched plastic film 31, second biaxially stretched plastic film 32 Alternatively, the third biaxially stretched plastic film 33 may be a glass film having at least a transparent deposition layer. The gas barrier film may be a gas barrier film on the surface of the transparent deposition layer. The substrate may further include a transparent gas barrier coating film formed on the substrate and having transparency.

[0100] The transparent deposition layer has a gas barrier function that prevents the permeation of oxygen gas and water vapor. The transparent deposition layer may function as a layer that supports the transparent layer. When the above components are present, they may have the same composition or different compositions. The transparent deposition layer can be formed by, for example, vacuum deposition, sputtering, and ion deposition. Physical Vapor Deposition Methods such as the Imprinting Method tion method, PVD method), or plasma chemical vapor deposition method, thermal chemical vapor deposition method, and Chemical Vapor Deposition (CCVD) tion method, CVD method, etc. Specifically, a roller type deposition film forming apparatus The deposition layer can be formed on the deposition roller by using the deposition roller.

[0101] The transparent deposition layer is made of a transparent inorganic material. Examples of the inorganic material include: Metal oxides and inorganic oxides can be mentioned. Metal oxides include aluminum (A l), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), Thorium (Na), Boron (B), Titanium (Ti), Lead (Pb), Zirconium (Zr) Examples of inorganic oxides include oxides of metals such as silicon (S i) oxide. The inorganic material constituting the transparent deposition layer is aluminum oxide. Aluminum oxide or silicon oxide is preferred.

[0102] The thickness of the transparent deposition layer is preferably 40 Å or more and 130 Å or less, more preferably 50 Å or less. or more and 120 Å or less.

[0103] The transparent gas barrier coating film functions as a layer that suppresses the permeation of oxygen gas and water vapor. The transparent gas barrier coating film is a layer represented by the general formula R 3 n M(OR 4 ) m (However, in the formula , R 3 , R 4 represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, and n is 0 or more. represents an integer, m represents an integer of 1 or more, and n+m represents the valence of M. At least one alkoxide and the polyvinyl alcohol resin and / or or an ethylene-vinyl alcohol copolymer, and further comprising a sol-gel catalyst, an acid, A transparent gas barrier composition that is polycondensed by a sol-gel method in the presence of water and an organic solvent. Obtained by things.

[0104] The above general formula R 3 n M(OR 4 ) m The alkoxide represented by the formula: Use at least one of partial hydrolysates and condensates of hydrolysis of alkoxides. In addition, the partial hydrolysis product of the above alkoxide can be obtained by removing all of the alkoxy groups. It is not necessary that all of the amino acids are hydrolyzed, but one or more of them are hydrolyzed, and mixtures thereof are also acceptable. The condensation product of hydrolysis of an alkoxide may be a partially hydrolyzed alkoxide. A dimer or more of cid, specifically a dimer to hexamer, is used.

[0105] The above general formula R 3 n M(OR 4 ) m In the alkoxide represented by the formula: The atomic group includes silicon, zirconium, titanium, aluminum, and others. In this embodiment, preferred metals include, for example, silicon and titanium. In the present embodiment, the alkoxide can be used in the following manner. Use alkoxides of one or more different metal atoms in the same solution. It is also possible.

[0106] In addition, the above general formula R 3 n M(OR 4 ) m In the alkoxide represented by the formula: 3 In table Specific examples of the organic group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and the like. propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group Examples of the alkyl group include an n-octyl group, an n-phenyl group, and the like. General formula R 3 n M(OR 4 ) m In the alkoxide represented by the formula: 4 The organic group represented by Specific examples include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl ... Examples of such groups include the ethyl group, the sec-butyl group, and others. The alkyl groups may be the same or different.

[0107] When preparing the gas barrier composition, for example, a silane coupling agent or the like is added. The silane coupling agent may be a known organoalkane having an organic reactive group. In this embodiment, a silane having an epoxy group can be used. Organoalkoxysilanes are preferably used, specifically, for example, γ-glycidoxypropyl. propyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-( 3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. can be used. The above silane coupling agents may be used alone or in combination of two or more.

[0108] Specific examples of the packaging material 30 include the following packaging materials. When listing layers, the notation is used to indicate the boundaries between layers. The layers are written from the outside to the inside. That is, the layer written on the right side is It is a sealant film. Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented nylon film / adhesive layer / biaxially oriented nylon film Axial stretched PET film / adhesive layer / sealant film Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented PET film / adhesive layer / biaxial Stretched nylon film / adhesive layer / sealant film Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented PET film / adhesive layer / biaxial Stretched PET film / adhesive layer / sealant film Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented nylon film / adhesive layer / biaxially oriented nylon film Axially stretched straight cut PET film / adhesive layer / sealant film Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented PET film / adhesive layer / biaxial Stretched straight cut nylon film / adhesive layer / sealant film Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented PET film / adhesive layer / biaxial Stretched straight cut PET film / adhesive layer / sealant film Biaxially oriented PET film / transparent deposition layer / transparent gas barrier coating film / printing layer / adhesive layer / two Axial stretched nylon film / adhesive layer / biaxial stretched PET film / adhesive layer / sealant film Film Biaxially oriented PET film / transparent deposition layer / transparent gas barrier coating film / printing layer / adhesive layer / two Axial stretched PET film / adhesive layer / biaxial stretched nylon film / adhesive layer / sealant film Film Biaxially oriented PET film / printed layer / adhesive layer / transparent gas barrier coating film / transparent vapor deposition layer / Axial stretched PET film / adhesive layer / biaxial stretched PET film / adhesive layer / sealant film Room

[0109] According to this embodiment, the sample is held in a 100° C. environment for 1 minute, and then measured in a 100° C. environment. The hot rupture strength in one direction (e.g., machine direction (MD)) when This means that the hot breaking strength is high. This can prevent bags from breaking.

[0110] The seal strength of the steam release seal part of a pouch heated to a high temperature in a microwave oven Once it is at a reasonably low value, it will be able to withstand the forces of water vapor generated in the containment space. The steam release seal is more easily peeled off. In other words, the steam release seal peels off at a lower pressure. According to this embodiment, the pouch 10 has a temperature of 100° C. The hot seal strength is 15.0N or less, so the hot seal strength is low and steam Steam can be easily released from the seal portion 26, and the steam can be released stably. do. EXAMPLES

[0111] In order to explain the present invention in detail, the following examples are given. Not limited to the description.

[0112] <Example 1> First, a first biaxially oriented plastic film, a second biaxially oriented plastic film, and a third biaxially oriented plastic film, a 12 μm thick biaxially oriented polyethylene film. Three sheets of ethyl terephthalate film (product name "E5100", manufactured by Toyobo Co., Ltd.) were prepared. Next, a printing layer was formed on one of the films. The thickness of the printing layer was 1.0 μm. In addition, a 60 μm thick unstretched polypropylene film was used as a sealant film. (Product name: ZK500, manufactured by Toray Film Processing Co., Ltd.) was prepared. The materials included the aforementioned propylene-ethylene block copolymers and elastomers.

[0113] ZK500 has higher tensile elongation than general unstretched polypropylene films. Specifically, the tensile elongation of ZK500 in the machine direction (MD) is When the thickness is 60 μm, the ratio is 1180%, and when the thickness is 60 μm, the ratio is 1100%. The tensile elongation of ZK500 in the case of 50 μm thickness is 1240%. For 60 μm, it is 1150%. Therefore, the tensile elongation of ZK500 in the machine direction ( The product of %) and thickness (μm) is 59000 when the thickness is 50 μm, and In the case of ZK500, the tensile elongation (%) and thickness ( The product of (μm) is 62000 when the thickness is 50 μm and 69 when the thickness is 60 μm. The number is 000.

[0114] Next, biaxially oriented polyethylene terephthalate film, A printing layer, a first adhesive layer, a biaxially oriented polyethylene terephthalate film, a second adhesive layer, Biaxially oriented polyethylene terephthalate film, a third adhesive layer and an unoriented polypropylene The first adhesive layer, second adhesive layer, and third adhesive layer were laminated in order to prepare a packaging material. Two-component polyurethane adhesive manufactured by Rock Paint Co., Ltd. (Base: RU-40, Hardener: The main agent, RU-40, is a polyester polyol. The thickness of the adhesive layer, the second adhesive layer and the third adhesive layer was 3.0 μm.

[0115] Then, three sheets of the packaging material prepared above were used to fill 200 ml of water and then placed in the container as shown in FIG. Specifically, we first prepared a standing pouch using the packaging material that will be the bottom film. In this case, the sealant film, unstretched polypropylene film, is placed on the outside. The sheet is folded in half to form a first portion and a second portion connected together via a fold line, When folded in half and cut into a pouch, the bottom edge will be near the bottom of both horizontal edges of the bottom surface. The area was punched out into a circular shape with a diameter of 10 mm to form a through hole.

[0116] And between the packaging material that will be the front film and the packaging material that will be the back film The packaging material that will become the bottom film folded in half is placed in a certain position and heat-sealed under the following conditions. a first pleat having a first side seal, a second side seal, and a first bottom seal; A second pleat having a bottom seal and a steam release seal were formed. The pouch was obtained with an open top. Note that the bottom of the pouch was folded in half at the through hole. Since there is no packaging material that can be used as a film, the packaging material that can be used as the front film and the back The film packaging material was directly fused to form the third bottom seal. (Heat fusion conditions) Heat sealing device: Heat sealer TP-701-A (manufactured by Tester Sangyosha Co., Ltd.) ·Heat fusion temperature: 220℃ Heat sealing pressure: 0.1MPa Heat fusion time: 1 second

[0117] After that, 200 ml of water was poured into each pouch from the opening, and the pouch was then heat-sealed under the same conditions as above. The pouch was sealed by heat sealing under the conditions of The pouch according to Example 1 was subjected to retort treatment under the following conditions. In Example 1, the machine direction (MD) of the packaging material was aligned with the X direction (DRX) of the pouch. The width direction (TD) of the packaging material corresponds to the Y direction DRY of the pouch. (retort processing) Method: Spray type Retort temperature: 135℃ Retort time: 40 minutes

[0118] In the pouch according to Example 1, the height H1 of the pouch is 160 mm. The width W1 is 147 mm, the height H2 of the first pleat and the height H3 of the second pleat are 46 mm. m, the width W2 of the first side seal and the second side seal is 7.0 mm, and the steam release seal The width W3 of the upper seal portion was 5 mm, and the width W4 of the upper seal portion was 10.0 mm.

[0119] <Example 2> In Example 2, the second biaxially stretched plastic film was a 12 μm thick biaxially stretched plastic film. Axially oriented polyethylene terephthalate film (product name "E5200", manufactured by Toyobo Co., Ltd.) Instead of a 15μm thick biaxially oriented nylon film (product name "Bonyl QC", Kogyo Co., Ltd.) The packaging material was prepared in the same manner as in Example 1, except that a packaging material made of acrylic resin (Hanshin Film & Chemicals Co., Ltd.) was used. Using these three sheets of packaging material, the same procedure as in Example 1 was carried out to prepare Example 2. Such a pouch was produced. In Example 2, the machine direction (MD) of the packaging material was the X direction of the pouch. The width direction (TD) of the packaging material corresponds to the Y direction DRY of the pouch. .

[0120] <Example 3> In Example 3, a biaxially stretched plastic film having a thickness of 12 μm was used as the third biaxially stretched plastic film. Axially oriented polyethylene terephthalate film (product name "E5200", manufactured by Toyobo Co., Ltd.) Instead of a 15μm thick biaxially oriented nylon film (product name "Bonyl QC", Kogyo Co., Ltd.) The packaging material was prepared in the same manner as in Example 1, except that a packaging material made of acrylic resin (Hanshin Film & Chemicals Co., Ltd.) was used. Using these three sheets of packaging material, the same procedure as in Example 1 was carried out to prepare Example 3. Such a pouch was produced. In Example 3, the machine direction (MD) of the packaging material was the X direction of the pouch. The width direction (TD) of the packaging material corresponds to the Y direction DRY of the pouch. .

[0121] <Comparative Example 1> In Comparative Example 1, a 70 μm-thick unstretched polypropylene film (product name “ZK2 07" (manufactured by Toray Film Processing Co., Ltd.) as a sealant film, with a thickness of 7 0 μm unstretched polypropylene film (product name "ZK99S", Toray Film Processing Co., Ltd. A packaging material was prepared in the same manner as in Example 1, except that a cellulose acetate sheet (manufactured by Epoxy Co., Ltd.) was used. A pouch according to Comparative Example 1 was produced in the same manner as in Example 1 using three sheets of packaging material. In Example 1, the machine direction (MD) of the packaging material corresponds to the X-direction (DRX) of the pouch, and the width direction of the packaging material corresponds to the The direction (TD) corresponds to the Y direction DRY of the pouch.

[0122] <Hot breaking strength measurement> 10% of the packaging material constituting the pouch after retort treatment in Examples 1 to 3 and Comparative Example 1 The breaking strength at 0° C. (hot breaking strength) was measured. As shown in FIG. 4, the front surface of each pouch was Then, not including the seal part, one side L1 is 15 mm, in the direction perpendicular to one side L1 Five rectangular test pieces S1 with the other side L2 of 100 mm were cut out. The test pieces S1 were The other side L2 is parallel to the X direction DRX (the direction perpendicular to the direction in which the first side seal portion extends). Next, as shown in FIG. 5, each pouch was cut from the back side without the seal portion. In this way, one side L1 is 15 mm, and the other side L2 extending in a direction perpendicular to the side L1 is 100 Five rectangular test pieces S2 with a length of 1.5 mm were cut out. The other side L2 of the test piece S2 is in the Y direction DRY (the direction parallel to the extension direction of the first side seal portion). And A Tensilon universal material testing machine RTC-1310A (manufactured by A&D Co., Ltd.) was used. After holding each test piece S1 for 1 minute in an environment with a temperature of 100°C and a relative humidity of 5%, Under an environment of 100°C and 5% relative humidity, the initial gripping distance D1 is 50 mm and the tensile speed is A tensile test was performed at a strain rate of 300 mm / min, and the hot rupture strength of the test piece S1 was measured. In the same manner, the hot rupture strength of the test piece S2 was measured. The breaking strength was measured, and the average value was taken as the hot breaking strength of the packaging material in the X direction. The hot breaking strength of the test piece S2 was measured, and the average value was calculated as the hot breaking strength in the Y direction of the packaging material. The strength was determined.

[0123] <Hot seal strength measurement> Sealing of pouches after retort treatment in Examples 1 to 3 and Comparative Example 1 at 100°C The strength (hot seal strength) of the retort packs according to Examples 1 to 3 and Comparative Example 1 was measured. One processed pouch was prepared. For each pouch, the first side seal was included, and the front surface was When the film and back film are joined, the side L3 is 15 mm, and the side perpendicular to the side L3 Five rectangular test pieces S3 with the other side L4 extending in the direction of the rod being 70 mm were cut out. As shown in FIG. 7, three pieces are provided to include the first side seal portion, and one piece is provided to include the second side seal portion. Two test pieces S3 were cut out. The other side L4 of the test piece S3 is in the X-direction DRX (first side seam The steam release seal portion is arranged parallel to the direction perpendicular to the direction in which the steam release seal portion extends. The test pieces were used to measure the hot seal strength. The strength of the ball is measured by the Tensilon universal material test in accordance with JIS Z1707:1997 7.5. The measurements were performed using a meter RTC-1310A (manufactured by A&D Co., Ltd.). The two sheets of packaging material in the unsealed portion of the test piece were each gripped with the gripping tool of the tensile tester. In addition, the gripping tools were each placed in a direction perpendicular to the surface direction of the seal portion of the test piece S3. The specimens were pulled in opposite directions at a speed of 300 mm / min, and the maximum tensile stress was measured. The average of the maximum values ​​was taken as the seal strength. The hot seal strength was measured at a temperature of 100°C. After being held in an environment of 5% relative humidity for 1 minute, the test was performed in an environment of 100°C and 5% relative humidity. Measure the hot seal strength of five or more test pieces S3, and calculate the average value of the hot seal strength of the pouch. The seal strength was measured.

[0124] The composition of the packaging materials and the evaluation results are shown in Table 1. [Table 1]

[0125] The results are described below. As shown in Table 1, the pouches according to Examples 1 to 3 were constructed. In the packaging material for the pouch according to Comparative Example 1, the X-direction Because of its high hot breaking strength, the pouch may expand due to steam when heated in a microwave oven. In addition, the pouch according to the first to third embodiments can be prevented from being torn. The packaging material constituting the pouch has a higher hot seal strength than the packaging material constituting the pouch of Comparative Example 1. Because the temperature is low, steam can easily escape through the steam release seal, allowing for stable steam release. It can be pulled out. [Explanation of symbols]

[0126] 10…Pouch 10A…Storage space 11…Front film 12…Back film 13...Bottom film 15…Seal section 26…Steam release seal 30...Packaging materials 31...first biaxially stretched plastic film 32...Second biaxially oriented plastic film 33...Third biaxially oriented plastic film 34…Sealant film

Claims

1. A pouch including a packaging material and having a receiving space, the packaging material comprises a first biaxially oriented plastic film, a second biaxially oriented plastic film, a third biaxially oriented plastic film, and a sealant film, in this order; The first biaxially oriented plastic film is mainly composed of polyester, The second biaxially oriented plastic film is mainly composed of polyester or polyamide, When the second biaxially oriented plastic film is mainly composed of polyester, the third biaxially oriented plastic film is mainly composed of polyester or polyamide, and when the second biaxially oriented plastic film is mainly composed of polyamide, the third biaxially oriented plastic film is mainly composed of polyester, The sealant film is mainly composed of polypropylene and contains a propylene-ethylene copolymer, The packaging material contains only three biaxially oriented plastic films, A seal portion for sealing the pouch is provided, The sealing portion includes a steam release seal portion configured to be peeled off by an increase in pressure in the storage space, The pouch is configured so that steam can be released by peeling off the steam release seal portion, The packaging material has a breaking strength in one direction of 50.0 MPa or more when measured in a 100° C. environment after being held in a 100° C. environment for 1 minute, The pouch has a seal strength of 4.0 N or more and 10.0 N or less when measured in an environment of 100°C after being held in an environment of 100°C for 1 minute.

2. 2. The pouch of claim 1, wherein the product of tensile elongation (%) and thickness (μm) in the one direction of the sealant film exceeds 50,000.

3. 3. The pouch according to claim 1, wherein the product of the tensile elongation (%) and the thickness (μm) of the sealant film in a direction perpendicular to the one direction exceeds 55,000.

4. The pouch according to any one of claims 1 to 3, wherein the first biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film, the second biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film or a biaxially oriented nylon film, and when the second biaxially oriented plastic film is the biaxially oriented polyethylene terephthalate film, the third biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film or a biaxially oriented nylon film, and when the second biaxially oriented plastic film is the biaxially oriented nylon film, the third biaxially oriented plastic film is a biaxially oriented polyethylene terephthalate film.

5. 5. The pouch of claim 1, wherein the packaging material further comprises a transparent vapor deposition layer disposed between the first biaxially oriented plastic film and the second biaxially oriented plastic film or between the second biaxially oriented plastic film and the third biaxially oriented plastic film, the transparent vapor deposition layer comprising a metal oxide or an inorganic oxide.

6. The pouch according to claim 5 , wherein the packaging material further comprises a transparent gas barrier coating film provided on a surface of the transparent vapor deposition layer.

7. The pouch according to claim 1 , wherein the pouch contains a content in the storage space.

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