JP2019069790A - Bread wrapping film and package of bakery goods - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bread wrapping film capable of suppressing the occurrence of tearing of a bag when filling a bag, particularly in winter, and improving the filling property of bread and the productivity of a product. A bread wrapping film 100 of the present invention is a bread wrapping film for wrapping bread, and is a core layer 101 containing polyolefin and a heat seal layer provided on one surface of the core layer 101. 3. The tear strength in the TD direction of the packaging film 100 for bread measured under the conditions of a measurement temperature of 23 ± 3 ° C. and a measurement humidity of 50 ± 5% RH using a light load tear tester. It is 0 N / mm or more, and the static friction coefficient (tan θ) of the surface of the bread packaging film 100 on the heat seal layer 103 side, which is measured by an inclination method using a slip tester, is 2.0 or less. [Selection diagram] Fig. 1

Description

  The present invention relates to a packaging film for bread and a packaging for bread.

Generally, a polyolefin resin film is used as a packaging film for bread.
As a technique regarding such a packaging film for breads, the thing as described in patent document 1 (Unexamined-Japanese-Patent No. 2003-55509) and patent document 2 (Unexamined-Japanese-Patent No. 2007-152730) is mentioned, for example.

In Patent Document 1, 75 to 85% by weight of a propylene polymer (A) and 4 to 12% by weight of an ethylene / α-olefin random copolymer (B) having a melt flow rate in the range of 3 to 10 g / 10 min. And a polyolefin film characterized in that it is obtained from a polyolefin composition with 8 to 18% by weight of ethylene polymer (C).
Patent Document 1 describes that a polyolefin film having the above-described configuration is excellent in melt-sealed seal strength and slip properties.

In Patent Document 2, a printing layer containing a resin composition comprising 70 to 100% by weight of a propylene-based block copolymer resin (C) and 0 to 30% by weight of a propylene-based block copolymer resin (D), Polyolefin comprising two layers of a seal layer comprising a resin composition consisting of 50 to 100% by weight of a propylene based random copolymer resin (A) and 0 to 50% by weight of an ethylene / α-olefin copolymer resin (B) Based resin laminated films are described. In Patent Document 2, in the above laminated film, the gloss of the surface of the printing layer is 13% or less, the wetting index of the surface of the printing layer is 34 to 36 mN / m, and the haze of the film is 60% or more. It is stated that it is a feature.
Patent Document 2 describes that a polyolefin resin laminated film having the above-mentioned configuration has a matte feeling and is excellent in solvent-based ink adhesion strength and its water-based printing bleeding resistance.

Japanese Patent Application Publication No. 2003-55509 Japanese Patent Application Publication No. 2007-152730

According to the study of the present inventors, a packaging bag made using a conventional polyolefin resin film is easily torn by contact or rubbing between the bread and the bag when filling the bag into the bag, particularly in winter. It turns out that there is a case. If the bag is torn, the productivity of the product is reduced.
Therefore, in the conventional packaging film for bread, rapid improvement is achieved from the viewpoint of suppressing the occurrence of tearing of the bag when filling the bag into the bag, especially in winter, and not reducing the filling property of the bread and the productivity of the product. Was required.

  The present invention has been made in view of the above-mentioned circumstances, and in the winter season, in particular, the occurrence of tearing of the bag when filling the bag into the bag can be suppressed, and the filling property of the bread and the productivity of the product are not reduced. It is an object of the present invention to provide a bread packaging film capable of improving productivity.

  The present inventors diligently studied to solve the above problems. As a result, when a film having a specific range of tear strength and static friction coefficient (tan θ) is used, the occurrence of tearing of the bag when filling the bread into the bag can be suppressed, and the filling property of the bread and the productivity of the product It has been found that a bread package can be obtained which can be improved, leading to the present invention.

  That is, according to the present invention, a bread packaging film and a bread packaging shown below are provided.

[1]
Bread packaging film for packaging bread,
A core layer comprising polyolefin,
A heat seal layer provided on one side of the core layer;
Equipped with
The tearing strength in the TD direction of the bread packaging film is 4.0 N / mm or more, which is measured using a light load tear tester at a measurement temperature of 23 ± 3 ° C. and a measurement humidity of 50 ± 5% RH. ,
A packaging film for bread, wherein the coefficient of static friction (tan θ) of the surface on the heat seal layer side of the packaging film for bread is measured by the following method 1 (inclination method) using a slip tester.
(Method 1)
Two sheets of the above-mentioned bread packaging film cut into a size of 50 mm × 75 mm (hereinafter referred to as bread packaging films 1 and 2) are prepared, one of which is the above-mentioned bread packaging film 1 for the above heat seal layer side Fix it to the inclined plate so that it is on top. Next, a friction body whose bottom (size is 41 mm × 26 mm) is made of brass is fixed to the center of the surface of the other side of the bread packaging film 2 opposite to the heat seal layer side. A weight is attached on the body so that the weight applied to the bread packaging film 2 from the friction body is 150 g. Next, the heat seal layer side surfaces of the two bread packaging films 1 and 2 are overlapped. Next, the inclined plate is inclined at a speed of 1 ° / sec, and the value of tan θ is determined from the angle θ when the upper packaging film 2 for bread has slipped out.
[2]
In the packaging film for bread as described in [1] above,
MD direction of the packaging film for bread according to JIS K 7127: 1999 measured at a measurement temperature of 23 ± 3 ° C., a measurement humidity of 50 ± 5% RH, and a tensile speed of 5 mm / min using a tensile tester. Young's modulus _{T 1} and TD direction of the sum of Young modulus _{T 2 (T 1 + T 2} ) packaging films for bread or less 1500MPa or more 700 MPa.
[3]
In the bread packaging film according to the above [1] or [2],
MD direction of the packaging film for bread according to JIS K 7127: 1999 measured at a measurement temperature of 23 ± 3 ° C., a measurement humidity of 50 ± 5% RH, and a tensile speed of 5 mm / min using a tensile tester. bread packaging film Young's modulus _{T 1} of the is equal to or less than 800MPa or more 300 MPa.
[4]
In the bread packaging film according to any one of the above [1] to [3],
The packaging film for breads whose impact strength of said packaging film for breads measured on conditions of 5 +/- 2 degreeC and 50 +/- 5% RH is 3.0 kg * cm or more and 8.0 kg * cm or less.
[5]
In the bread packaging film according to any one of the above [1] to [4],
A packaging film for bread, wherein the piercing strength of the packaging film for bread is 1.5 N or more and 3.5 N or less, which is measured under the conditions of 23 ± 2 ° C. and 50 ± 5% RH in accordance with JIS Z1707: 1997.
[6]
In the bread packaging film according to any one of the above [1] to [5],
A packaging film for bread, wherein the polyolefin comprises a propylene-based block copolymer.
[7]
In the packaging film for bread as described in the above [6],
The bread package wherein the content of the propylene-based block copolymer contained in the core layer is 50% by mass or more and 100% by mass or less when the content of the polyolefin contained in the core layer is 100% by mass. the film.
[8]
In the bread packaging film according to the above [6] or [7],
Pan according to JIS K 7210, wherein the melt flow rate (MFR) of the propylene-based block copolymer measured under conditions of 230 ° C. and 2.16 kg load is 0.5 g / 10 min or more and 20 g / 10 min or less Packaging film.
[9]
In the packaging film for bread according to any one of the above [1] to [8],
A packaging film for bread further comprising a surface layer on the surface of the core layer opposite to the surface on which the heat seal layer is provided.
[10]
In the packaging film for bread as described in the above [9],
The packaging film for bread, wherein the surface layer is one or more selected from homopolypropylene, a propylene-based block copolymer, and a random copolymer of propylene and an α-olefin having 2 to 10 carbon atoms.
[11]
In the bread packaging film according to any one of the above [1] to [10],
The packaging film for bread, wherein the heat seal layer is provided to be in direct contact with the one surface of the core layer.
[12]
In the packaging film for bread according to any one of the above [1] to [11],
The packaging film for bread, wherein the heat seal layer comprises one or more selected from homopolypropylene and a random copolymer of propylene and an α-olefin having 2 or more and 10 or less carbon atoms.
[13]
In the bread packaging film according to any one of the above [1] to [12],
A packaging film for bread, wherein the bread comprises bread.
[14]
The package for breads using the packaging film for breads as described in any one of said [1] thru | or [13].

  According to the present invention, it is possible to provide a bread packaging film which can suppress the occurrence of tearing of the bag when filling the bag into the bag, particularly in winter, and can improve the filling property of the bread and the productivity of the product. Can.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which showed typically an example of the structure of the packaging film for bread | pans of embodiment which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which showed typically an example of the structure of the packaging film for bread | pans of embodiment which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described using the drawings. Note that the figure is a schematic view and does not match the actual dimensional ratio. In addition, "-" in between the numbers in a sentence represents above from the following, unless there is particular notice.

<Packaging film for bread>
FIG. 1: and FIG. 2 are sectional drawings which showed typically an example of the structure of the packaging film 100 for bread | pans of embodiment which concerns on this invention.
The bread packaging film 100 according to the present embodiment is a bread packaging film for packaging bread, and includes a core layer 101 containing polyolefin and a heat seal layer 103 provided on one surface of the core layer 101. The tear strength of the packaging film for bread 100 in the TD direction is 4.0 N / °, measured under conditions of a measurement temperature of 23 ± 3 ° C. and a measurement humidity of 50 ± 5% RH using a light load tear tester. The static friction coefficient (tan θ) of the surface on the heat seal layer 103 side of the bread packaging film 100 measured by the inclination method using a slip tester and being 2.0 mm or less.
(Method 1)
Prepare two bread packaging films according to this embodiment cut into a size of 50 mm × 75 mm (hereinafter referred to as bread packaging films 1 and 2) and heat seal one bread packaging film 1 of them. It fixes to an inclination board so that the layer 103 side may become upper side. Next, a friction body whose bottom (size is 41 mm × 26 mm) is made of brass is fixed to the center of the surface of the other side of the bread packaging film 2 opposite to the heat seal layer 103 side. On the above, a weight is attached such that the weight applied to the bread packaging film 2 from the friction body is 150 g. Subsequently, the heat seal layer 103 side surfaces of the two packaging films 1 and 2 for bread are overlapped. Next, the inclined plate is inclined at a speed of 1 ° / sec, and the value of tan θ is obtained from the angle θ when the upper packaging film 2 for bread has slipped out.

As described above, according to the study of the present inventors, the packaging bag produced using the conventional polyolefin resin film is in contact with the bread and the bag when the bag is filled with the bread, particularly in the winter season. It became clear that there was a case where it was easy to tear by rubbing etc. If the bag is torn, the productivity of the product is reduced.
Therefore, in the conventional packaging film for bread, rapid improvement is achieved from the viewpoint of suppressing the occurrence of tearing of the bag when filling the bag into the bag, especially in winter, and not reducing the filling property of the bread and the productivity of the product. Was required.

The present inventors diligently studied to solve the above problems. As a result, when the bread packaging film 100 having a tear strength equal to or higher than the lower limit and a static friction coefficient (tan θ) equal to or lower than the upper limit, tearing of the bag when the bag is filled with bread It has been found that a package for bread can be obtained which can suppress the occurrence and improve the filling properties of the bread and the productivity of the product.
Here, when the bread packaging film 100 is used, the reason why the occurrence of tearing of the bag when filling the bread into the bag can be suppressed is not necessarily clear, but the following reasons can be considered.
First, by controlling the tearing strength of the bread packaging film 100 to the lower limit value or more, the tolerance of the bread packaging film 100 against contact with the bread, rubbing, etc. is enhanced. Furthermore, by controlling the static friction coefficient (tan θ) to be less than or equal to the above upper limit, the slipperiness of the bread relative to the bag is improved, and the bread can be smoothly filled into the inside of the bag. The friction generated between the and the pan can be reduced. And it is guessed that generation | occurrence | production of the tear of the bag by the contact and rubbing with bread and a bag can be suppressed by these synergistic effects.
That is, according to the bread packaging film 100 according to the present embodiment, by controlling the tear strength and the static friction coefficient (tan θ) within a certain range, the occurrence of tearing of the bag when filling the bag into the bag can be suppressed. Thus, it is possible to realize a bread package which can improve the filling property of the bread and the productivity of the product.
From the above, according to the present embodiment, it is possible to provide a bread package which can suppress the occurrence of tearing of the bag when filling the bread into the bag and can improve the filling property of the bread and the productivity of the product. Can.

In the bread packaging film 100 according to the present embodiment, the tear strength in the TD direction is 4.0 N / mm or more, but from the viewpoint of being able to further suppress the occurrence of tearing of the bag when filling the bag into the bag, It is preferably 4.5 N / mm or more, more preferably 5.0 N / mm or more, and still more preferably 5.5 N / mm or more.
Further, in the bread packaging film 100 according to the present embodiment, the upper limit value of the tear strength in the TD direction is not particularly limited, but is, for example, 12 N / mm or less, preferably 10 N / mm or less.

In the bread packaging film 100 according to the present embodiment, the static friction coefficient (tan θ) of the surface on the heat seal layer 103 side is 2.0 or less, but the occurrence of tearing of the bag when filling the bread into the bag is further enhanced. From the viewpoint of suppression, 1.7 or less is preferable, 1.5 or less is more preferable, 0.7 or less is more preferable, and 0.5 or less is particularly preferable.
Further, in the bread packaging film 100 according to the present embodiment, the lower limit value of the static friction coefficient (tan θ) of the surface on the heat seal layer 103 side is not particularly limited, but is, for example, 0.01 or more.

In the present embodiment, for example, by appropriately adjusting (1) the type and blending ratio of the polyolefin constituting the core layer 101, and (2) the constituent material and thickness of the heat seal layer 103 and the surface layer 105, etc. It is possible to control the tear strength of the packaging film 100 and the static friction coefficient (tan θ) of the surface on the heat seal layer 103 side within the above range.
Among these, for example, a propylene-based block copolymer is contained as the polyolefin constituting the core layer 101, two or more propylene-based block copolymers having different molecular weights (MFRs) are used as the polyolefins, and the molecular weights (MFRs) are different. The blending ratio of the propylene-based block copolymer can be cited as factors for setting the tear strength of the bread packaging film 100 and the static friction coefficient (tan θ) of the surface on the heat seal layer 103 side to a desired numerical range.

  Here, since the ears of the bread are sharp, when the bread is filled into the bag, the ears of the bread collide with the inner surface of the bag, and the tearing of the bag tends to be particularly likely to occur. Therefore, the packaging film 100 for bread according to the present embodiment can be particularly suitably used as a film constituting a packaging body for bread for packaging bread.

In the packaging film 100 for bread according to the present embodiment, the measurement temperature is 23 ± 3 ° C., the measurement humidity is 50 ± 5% RH, and the tensile speed is 5 mm / min according to JIS K7127: 1999. The total value (T ₁ + T ₂ ) of Young's modulus T ₁ in the MD direction and Young's modulus T _{2 in the} TD direction to be measured is preferably 700 MPa or more and 1500 MPa or less, and more preferably 800 MPa or more and 1350 MPa or less It is more preferably 900 MPa or more and 1250 MPa or less, and particularly preferably 950 MPa or more and 1150 MPa or less.
When the sum (T ₁ + T ₂ ) of the Young's modulus T _{1 in the} MD direction and the Young's modulus T _{2 in the} TD direction is within the above range, the stiffness of the bread packaging film 100 according to the embodiment is even better. As a result, it is possible to suppress displacement of the film at the time of heat sealing and the like, and to further suppress the occurrence of sealing failure.
That is, when the total value (T ₁ + T ₂ ) of Young's modulus T ₁ in the MD direction and Young's modulus T _{2 in the} TD direction is within the above range, the packaging suitability of the packaging film 100 for bread according to the present embodiment It can be made even better.
The total value (T ₁ + T ₂ ) of the Young's modulus T _{1 in the} MD direction and the Young's modulus T _{2 in the} TD direction is, for example, the type and content of the polyolefin contained in the core layer 101, the heat seal layer 103 or This can be achieved by adjusting the constituent material, thickness and the like of the surface layer 105.

In the bread packaging film 100 according to the present embodiment, the measurement temperature is 23 ± 3 ° C., the measurement humidity is 50 ± 5% RH, and the tensile speed is 5 mm / min according to JIS K 7127: 1999 using a tensile tester. Young's modulus T ₁ in the MD direction measured under the conditions is preferably 300 MPa or more and 800 MPa or less, more preferably 350 MPa or more and 700 MPa or less, still more preferably 400 MPa or more and 650 MPa or less, and 450 or more and 600 MPa or less Being particularly preferred.
When the Young's modulus T _{1 in the} MD direction is within the above range, the stiffness of the bread packaging film 100 according to the present embodiment can be further improved. As a result, the position of the film when heat sealing is performed. Deviation or the like can be suppressed, and the occurrence of sealing failure can be further suppressed.
That is, when the Young's modulus T ₁ of the MD direction is within the above range, it is possible to make the packaging quality bread packaging film 100 according to this embodiment even more favorable.
Such Young's modulus T _{1 in the} MD direction can be achieved, for example, by adjusting the type and content of the polyolefin contained in the core layer 101, the constituent material and thickness of the heat seal layer 103 and the surface layer 105, and the like.

In the bread packaging film 100 according to the present embodiment, from the viewpoint of being able to further suppress the occurrence of tearing of the bag when filling the bread into the bag, the impact measured under the conditions of 5 ± 2 ° C. and 50 ± 5% RH. The strength is preferably 3.0 kg · cm or more and 8.0 kg · cm or less, more preferably 4.0 kg · cm or more and 7.0 kg · cm or less, and 4.5 kg · cm or more and 6.5 kg · cm It is more preferable that it is the following.
Such impact strength can be achieved, for example, by adjusting the type and content of the polyolefin contained in the core layer 101, the constituent material and thickness of the heat seal layer 103 and the surface layer 105, and the like.

In the bread packaging film 100 according to the present embodiment, from the viewpoint of being able to further suppress the occurrence of tearing of the bag when filling the bread into the bag, 23 ± 2 ° C., 50 ± 5 according to JIS Z1707: 1997. The puncture strength measured under the condition of% RH is preferably 1.5 N or more and 3.5 N or less, and more preferably 2.0 N or more and 3.5 N or less.
Such piercing strength can be achieved, for example, by adjusting the type and content of the polyolefin contained in the core layer 101, the constituent material and thickness of the heat seal layer 103 and the surface layer 105, and the like.

The thickness of the bread packaging film 100 according to the present embodiment is not particularly limited, but tear resistance, impact resistance, water vapor barrier property, cost, bag-making property, mechanical properties, handleability, appearance, transparency, moldability The thickness can be set arbitrarily according to the desired purpose such as lightness, and is not particularly limited, but usually 5 μm to 100 μm, preferably 10 μm to 50 μm, and more preferably 15 μm to 40 μm. .
Tear resistance, impact resistance, water vapor barrier property, cost, bag-making property, mechanical property, handleability, appearance, transparency, moldability, light weight when the thickness of the packaging film 100 for bread is within the above range The balance of etc is better.

  Hereinafter, each layer which comprises the packaging film 100 for bread | pans is demonstrated.

[Core layer]
The core layer 101 according to the present embodiment can be formed of, for example, a resin composition (P) containing a polyolefin.

  The core layer 101 according to the present embodiment may be a single layer, or a plurality of layers formed of the resin composition (P) may be stacked. In addition, the core layer 101 according to the present embodiment may be unstretched, or may be uniaxially stretched or biaxially stretched.

  In the bread packaging film 100, the ratio of the thickness of the core layer 101 to the total thickness of the bread packaging film 100 is preferably 0.40 or more and 0.998 or less, more preferably 0.50 or more and 0. 0 or less. It is 99 or less, more preferably 0.55 or more and 0.97 or less, and particularly preferably 0.60 or more and 0.95 or less.

(Polyolefin)
The resin composition (P) according to the present embodiment, that is, the core layer 101 contains a polyolefin. As a result, it is possible to obtain the core layer 101 excellent in performance balance such as tear resistance, impact resistance, heat resistance, water vapor barrier property, transparency, mechanical properties and rigidity.
The polyolefin according to the present embodiment includes, for example, homopolymers or copolymers of α-olefins such as ethylene, propylene, butene-1, hexene-1, 4-methyl-pentene-1 and octene-1; Density polyethylene; linear low density polyethylene (LLDPE); high density polyethylene; polypropylene; random copolymer of propylene and α-olefin having 2 to 10 carbon atoms; propylene-based block copolymer; ethylene / vinyl acetate copolymer Polymer (EVA); ionomer resin etc. are mentioned. These polyolefins may be used alone or in combination of two or more.
Among these, the polyolefin according to the present embodiment preferably contains a propylene-based block copolymer from the viewpoint of being able to further suppress the occurrence of tearing of the bag when filling the bread into the bag.

  For example, a block copolymer of propylene and an α-olefin having 2 to 10 carbon atoms (excluding propylene) can be used as the propylene-based block copolymer according to the present embodiment. As an alpha-olefin, ethylene, 1-butene, 1-hexene, 4-methyl 1-pentene, 1-octene etc. are mentioned, for example. Among these, ethylene is preferable because of its excellent balance of cold resistance and rigidity.

In addition, the propylene-based block copolymer according to the present embodiment is composed of one or more selected from the group consisting of a polymer part composed of propylene and ethylene and an α-olefin having 4 to 20 carbon atoms. It is more preferable that it is a copolymer containing a polymer part.
Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1- Hexadecene, 1-octadecene, 1-eicosene and the like can be mentioned.
As an α-olefin constituting a polymer portion constituted of one or more selected from the group consisting of ethylene and an α-olefin having 4 to 20 carbon atoms in the propylene-based block copolymer according to the present embodiment, Ethylene or α-olefin having 4 to 10 carbon atoms is preferable, and ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene are more preferable. One of these α-olefins may be used alone, or two or more thereof may be used in combination.
Further, in the propylene-based block copolymer according to the present embodiment, the polymer portion composed of propylene is a matrix portion of the propylene-based block copolymer, and a group consisting of ethylene and an α-olefin having 4 to 20 carbon atoms It is preferable that the polymer part comprised by 1 or more types selected from is a structure which is a domain part.

  The content of α-olefin in the propylene-based block copolymer according to the present embodiment is preferably 1% by mass or more and 20% by mass or less, and more preferably 2% by mass or more, from the viewpoint of being further excellent in impact resistance and rigidity. The content is more preferably 15% by mass or less, and still more preferably 3% by mass or more and 12% by mass or less.

  The melting point of the propylene-based block copolymer according to the present embodiment is a viewpoint to further improve the balance of the heat resistance, transparency, mechanical properties, rigidity, flowability, moldability, etc. of the obtained packaging film 100 for bread. It is preferably in the range of 150 ° C. or more and 175 ° C. or less, more preferably 155 ° C. or more and 170 ° C. or less, still more preferably 160 ° C. or more and 168 ° C. or less.

  Melt flow rate (MFR) of a propylene-based block copolymer according to the present embodiment measured under the conditions of 230 ° C. and a 2.16 kg load in accordance with JIS K 7210, from the viewpoint of making the flowability and the formability better It is preferably 0.5 g / 10 min or more, more preferably 1 g / 10 min or more, still more preferably 2 g / 10 min or more, and from the viewpoint of further stabilizing moldability, preferably 20 g / 10 min or less. More preferably, it is 15 g / 10 minutes or less, still more preferably 12 g / 10 minutes or less.

As polyolefin which comprises core layer 101 concerning this embodiment, based on JIS K 7210, MFR measured on conditions of 230 ° C and 2.16 kg load is 0.5 g / 10 minutes or more and 5.0 g / 10 minutes or less Propylene block copolymer 1 and a propylene block copolymer having an MFR of more than 5.0 g / 10 min and not more than 20 g / 10 min measured under the conditions of 230 ° C. and 2.16 kg load according to JIS K 7210 It is preferable to use 2 in combination.
Further, the ratio of the content of the propylene block copolymer 1 and the propylene block copolymer 2 in the core layer 101 is the mass ratio of propylene block copolymer 1 / propylene block copolymer 2 = It is preferably 15/85 to 90/10, and more preferably 20/80 to 85/15. This can further improve the resistance to puncture and abrasion, particularly at low temperatures.

  The propylene-based block copolymer according to the present embodiment may be used alone or in combination of two or more.

  The propylene-based block copolymer according to this embodiment can be produced by various methods. For example, it can manufacture using well-known catalysts, such as a Ziegler natta type | system | group catalyst and a metallocene type catalyst.

  The content of the resin composition (P) according to the present embodiment, that is, the content of the propylene-based block copolymer contained in the core layer 101 is from the viewpoint of being able to further suppress the occurrence of tearing of the bag when filling the bread into the bag When content of the polyolefin contained in the core layer 101 is 100 mass%, preferably 50 mass% to 100 mass%, more preferably 70 mass% to 100 mass%, further preferably 80 mass% to 100 mass. % Or less, still more preferably 90% by mass or more and 100% by mass or less, particularly preferably 95% by mass or more and 100% by mass or less.

  The resin composition (P) according to the present embodiment, that is, the content of the polyolefin contained in the core layer 101 is preferably 50% by mass to 100% by mass, more preferably 100% by mass of the entire core layer 101. Is 70% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and particularly preferably 95% by mass to 100% by mass. Thereby, the balance of tear resistance, impact resistance, water vapor barrier property, bag-making property, mechanical property, handleability, appearance, transparency, moldability, lightness, etc. can be made better.

(Other ingredients)
In the resin composition (P) according to the present embodiment, if necessary, a tackifier, a heat stabilizer, a weathering stabilizer, an antioxidant, an ultraviolet absorber, a lubricant, a slip agent, a nucleating agent, an antiblocking agent Various additives such as an antistatic agent, an antifogging agent, a pigment, a dye, an inorganic or organic filler and the like may be added within the range not impairing the purpose of the present embodiment.

(Preparation method of resin composition (P))
The resin composition (P) according to the present embodiment is, for example, mixing or melting of the respective components by dry blending, tumbler mixer, Banbury mixer, single screw extruder, twin screw extruder, high speed twin screw extruder, hot roll or the like. -It can be prepared by kneading.

[Heat seal layer]
The bread packaging film 100 which concerns on this embodiment equips one surface of the core layer 101 with the heat seal layer 103, in order to provide heat sealability.
The heat seal layer 103 is preferably provided on the outermost layer of the bread packaging film 100 according to the present embodiment from the viewpoint of making the heat sealing properties of the bread packaging film 100 better.

  The heat seal layer 103 is preferably provided to be in direct contact with the surface of the core layer 101. Thereby, the manufacturing process of the packaging film 100 for bread | pans can be simplified.

In the packaging film 100 for bread, the thickness of the heat seal layer 103 is preferably 0.1 μm to 10 μm, more preferably 0.2 μm to 9 μm, still more preferably 0.5 μm to 8 μm, particularly preferably 1 μm to 8 μm. It is below.
When the thickness of the heat seal layer 103 is not less than the above lower limit value, the heat sealability of the bread packaging film 100 can be further improved.
In addition, when the thickness of the heat seal layer 103 is less than or equal to the above upper limit, the adhesiveness with the core layer 101 is improved, and the heat seal layer 103 can be easily laminated on the core layer 101 without using an adhesive. It becomes.
That is, since the heat seal layer 103 can be easily provided to be in direct contact with the surface of the core layer 101, the manufacturing process of the bread packaging film 100 can be simplified.

  In the bread packaging film 100, the heat seal layer 103 provided on one side is preferably a single layer. Thereby, the manufacturing process of the packaging film 100 for breads can be further simplified.

  In addition, the heat seal layer 103 may be uniaxially or biaxially stretched simultaneously with the film in the state before the stretching of the core layer 101. In this way, the uniaxially or biaxially stretched bread packaging film 100 can be produced using a forming method such as co-extrusion molding method, that is, a laminated film produced by one-time forming, so a bread packaging film The manufacturing process of 100 can be further simplified.

(Polyolefin)
The heat seal layer 103 according to the present embodiment is made of, for example, a polyolefin resin composition (A) containing a polyolefin. Examples of the polyolefin constituting the heat seal layer 103 include homopolymers or copolymers of α-olefins such as ethylene, propylene, butene-1, hexene-1, 4-methyl-pentene-1 and octene-1; High pressure low density polyethylene; linear low density polyethylene (LLDPE); high density polyethylene; polypropylene; random copolymer of propylene and α-olefin having 2 to 10 carbon atoms; ethylene / vinyl acetate copolymer (EVA) And ionomer resins. These polyolefins may be used alone or in combination of two or more.
Among these, as the polyolefin constituting the heat seal layer 103, homopolypropylene and propylene and an α- of 2 or more and 10 or less carbon atoms are preferred because the adhesiveness with the core layer 101 and the balance of heat sealability are excellent. At least one selected from random copolymers with olefins is preferred.

The propylene / α-olefin random copolymer according to this embodiment is a random copolymer of propylene and α-olefin (however, α-olefin excludes propylene), and as the α-olefin, for example, ethylene 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and the like. These copolymers may be used alone or in combination of two or more.
Among the propylene / α-olefin random copolymers, propylene / ethylene random copolymers, propylene / ethylene / 1-butene random copolymers, and propylene / 1-butene random copolymers are preferable.

The melting point of the polyolefin constituting the heat seal layer 103 according to this embodiment is preferably 50 ° C. or more and 175 ° C. or less, more preferably 60 ° C. or more and 170 ° C. or less, still more preferably 65 ° C. or more and 167 ° C. or less. The stickiness of the surface of the heat seal layer 103 can be suppressed as the melting point of the polyolefin is at least the above lower limit value, and the blocking resistance of the bread packaging film 100 can be improved.
Moreover, the heat sealability of the packaging film 100 for breads can be made more favorable for the melting point of polyolefin to be below the said upper limit.

  The melt flow rate (MFR) of the polyolefin constituting the heat seal layer 103 according to this embodiment measured under the conditions of 230 ° C. and a load of 2.16 kg according to JIS K 7210 has better flowability and moldability. From the viewpoint of curing, preferably 0.5 g / 10 min or more, more preferably 1 g / 10 min or more, and still more preferably 2 g / 10 min or more, and from the viewpoint of further stabilizing moldability, preferably 20 g / 10 min. The content is more preferably 15 g / 10 minutes or less, further preferably 10 g / 10 minutes or less.

  The content of polyolefin in the polyolefin resin composition (A) according to the present embodiment, that is, the heat seal layer 103 is preferably 50% by mass or more, based on 100% by mass of the entire polyolefin resin composition (A). The content is 100% by mass or less, more preferably 70% by mass to 100% by mass, still more preferably 90% by mass to 100% by mass, and particularly preferably 95% by mass to 100% by mass. As a result, the balance between the adhesion to the core layer 101 and the heat sealability can be further improved.

(Other ingredients)
In the polyolefin resin composition (A) constituting the heat seal layer 103 according to the present embodiment, as needed, a tackifier, a heat stabilizer, a weathering stabilizer, an antioxidant, an ultraviolet absorber, a lubricant, Various additives such as a slip agent, a nucleating agent, an antiblocking agent, an antistatic agent, an antifogging agent, a pigment, a dye, an inorganic or organic filler and the like may be added within the range not impairing the purpose of the present embodiment.

(Method of preparing polyolefin resin composition (A))
The polyolefin resin composition (A) which concerns on this embodiment mixes each component, for example by dry blending, tumbler mixer, Banbury mixer, single screw extruder, twin screw extruder, high-speed twin screw extruder, heat roll etc. Alternatively, it can be prepared by melting and kneading.

[Surface layer]
The bread packaging film 100 according to the present embodiment has a surface layer on the surface of the core layer 101 opposite to the surface provided with the heat seal layer 103 as shown in FIG. 2 in order to improve the printability of the surface. It is preferable to further include 105.
The surface layer 105 is preferably provided on the outermost layer of the bread packaging film 100 according to the present embodiment, from the viewpoint of making the printability of the bread packaging film 100 better.

  The surface layer 105 is preferably provided to be in direct contact with the surface of the core layer 101. Thereby, the manufacturing process of the packaging film 100 for bread | pans can be simplified.

In bread packaging film 100, the thickness of surface layer 105 is preferably 0.1 to 10 μm, more preferably 0.2 to 9 μm, still more preferably 0.5 to 8 μm, particularly preferably 1 to 8 μm. It is.
When the thickness of the surface layer 105 is not less than the above lower limit value, the printability of the bread packaging film 100 can be further improved.
In addition, when the thickness of the surface layer 105 is less than or equal to the above upper limit, adhesion with the core layer 101 is improved, and it becomes easy to stack the surface layer 105 on the core layer 101 without using an adhesive. .
That is, since it becomes easy to provide surface layer 105 so that it may touch directly on the surface of core layer 101, the manufacturing process of packaging film 100 for breads can be simplified.

  In bread packaging film 100, surface layer 105 is preferably a single layer. Thereby, the manufacturing process of the packaging film 100 for breads can be further simplified.

  Also, the surface layer 105 may be uniaxially or biaxially stretched simultaneously with the film in the state before stretching of the core layer 101. In this way, the uniaxially or biaxially stretched bread packaging film 100 can be produced using a forming method such as co-extrusion molding method, that is, a laminated film produced by one-time forming, so a bread packaging film The manufacturing process of 100 can be further simplified.

  The surface layer 105 may be subjected to surface treatment from the viewpoint of making the printability of the bread packaging film 100 better. Specifically, surface activation treatment such as corona treatment, flame treatment, plasma treatment, primer coating treatment, or ozone treatment may be performed.

(Polyolefin)
The surface layer 105 which concerns on this embodiment is comprised, for example with the polyolefin resin composition (B) containing polyolefin. Examples of the polyolefin constituting the surface layer 105 include homopolymers or copolymers of α-olefins such as ethylene, propylene, butene-1, hexene-1, 4-methyl-pentene-1 and octene-1; high pressure Low density polyethylene; linear low density polyethylene (LLDPE); high density polyethylene; polypropylene; random copolymer of propylene and α-olefin having 2 to 10 carbon atoms; propylene-based block copolymer; ethylene, acetic acid Vinyl copolymer (EVA); ionomer resin etc. are mentioned. These polyolefins may be used alone or in combination of two or more.
Among them, as the polyolefin constituting the surface layer 105, homopolypropylene, a propylene-based block copolymer, propylene and carbon number of 2 or more are preferable from the viewpoint that the adhesion with the core layer 101 and the balance of printability are excellent. At least one selected from random copolymers with 10 or less α-olefins is preferred.

The propylene / α-olefin random copolymer according to this embodiment is a random copolymer of propylene and α-olefin (however, α-olefin excludes propylene), and as the α-olefin, for example, ethylene 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and the like. These copolymers may be used alone or in combination of two or more.
Among the propylene / α-olefin random copolymers, propylene / ethylene random copolymers, propylene / ethylene / 1-butene random copolymers, and propylene / 1-butene random copolymers are preferable.

  As a propylene-type block copolymer used for the surface layer 105, the thing similar to the propylene-type block copolymer mentioned above used for the core layer 101 can be used preferably, for example. The propylene-based block copolymer may be used alone or in combination of two or more.

  The melting point of the polyolefin constituting the surface layer 105 according to this embodiment is preferably 90 ° C. or more and 175 ° C. or less, more preferably 95 ° C. or more and 170 ° C. or less, and further preferably 100 ° C. or more and 167 ° C. or less. The stickiness of the surface of surface layer 105 can be suppressed as the melting point of polyolefin is more than the above-mentioned lower limit, and the blocking resistance of bread packaging film 100 can be improved.

  The melt flow rate (MFR) of the polyolefin constituting the surface layer 105 according to the present embodiment measured under the conditions of 230 ° C. and a 2.16 kg load in accordance with JIS K 7210 has a good flowability and formability. It is preferably 0.5 g / 10 min or more, more preferably 1 g / 10 min or more, still more preferably 2 g / 10 min or more, and from the viewpoint of further stabilizing moldability, preferably 20 g / 10 min or less. More preferably, it is 15 g / 10 minutes or less, more preferably 10 g / 10 minutes or less.

  The content of the polyolefin in the polyolefin resin composition according to the present embodiment, that is, the surface layer 105 is preferably 50% by mass to 100% by mass, based on 100% by mass of the entire polyolefin resin composition (B). More preferably, they are 70 mass% or more and 100 mass% or less, More preferably, they are 90 mass% or more and 100 mass% or less, Especially preferably, 95 mass% or more and 100 mass% or less. Thereby, the balance with the core layer 101 and the printability can be made better.

(Other ingredients)
In the polyolefin resin composition (B) constituting the surface layer 105 according to the present embodiment, if necessary, a tackifier, a heat stabilizer, a weathering stabilizer, an antioxidant, an ultraviolet absorber, a lubricant, a slip Various additives such as an agent, a nucleating agent, an antiblocking agent, an antistatic agent, an antifogging agent, a pigment, a dye, an inorganic or organic filler and the like may be added within the range not impairing the purpose of the present embodiment.

(Preparation method of polyolefin resin composition (B))
The polyolefin resin composition (B) which concerns on this embodiment mixes each component by a dry blend, a tumbler mixer, a Banbury mixer, a single screw extruder, a twin screw extruder, a high speed twin screw extruder, a heat roll etc., for example Alternatively, it can be prepared by melting and kneading.

<Production Method of Packaging Film for Bread>
The bread packaging film 100 according to the present embodiment includes, for example, a resin composition (P) for forming the core layer 101, and a polyolefin resin composition (A) for forming the heat seal layer 103. Accordingly, it can be obtained by coextrusion of the polyolefin resin composition (B) for forming the surface layer 105 in the form of a film. Moreover, you may uniaxially stretch or biaxially stretch the laminated | multilayer film obtained by co-extrusion using a well-known uniaxial stretching method or a biaxial stretching method.
The molding apparatus and the molding conditions are not particularly limited, and conventionally known molding apparatuses and molding conditions can be adopted. As a molding apparatus, a multilayer T-die extruder, a multilayer inflation molding machine or the like can be used.
The bread packaging film 100 according to the present embodiment can also be obtained by separately molding the core layer 101, the heat seal layer 103, and the surface layer 105 as needed, and laminating these and heating and forming them. be able to.

  The bread packaging film 100 which concerns on this embodiment can be used suitably as a film which comprises the package for bread. The bread package according to the present embodiment is, for example, a packaging bag itself used for the purpose of containing bread, or one in which the bread is contained in the bag. In addition, the bread package according to the present embodiment may use the bread packaging film 100 for a part thereof depending on the application, or may use the bread packaging film 100 for the entire bread packaging. .

  Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than the above can also be adopted.

  Hereinafter, the present embodiment will be described in detail with reference to Examples and Comparative Examples. In addition, this embodiment is not limited at all to the description of these Examples.

1. Raw materials The raw materials used in Examples and Comparative Examples are shown below.

(1) Propylene-based block copolymer bPP1: Propylene-based block copolymer (MFR: 6.8 g / 10 min, melting point: 164 ° C., density: 910 kg / m ³ , manufactured by Prime Polymer Co., Ltd.)
bPP2: Propylene block copolymer (MFR: 2.5 g / 10 min, melting point: 164 ° C., density: 910 kg / m ³ , manufactured by Prime Polymer Co.)
bPP 3: Propylene-based block copolymer (MFR: 3.8 g / 10 min, melting point: 132 ° C./162° C., density: 910 kg / m ³ , manufactured by Prime Polymer Co.)
bPP 4: Propylene block copolymer (MFR: 2.6 g / 10 min, melting point: 164 ° C., density: 910 kg / m ³ , manufactured by Prime Polymer Co.)
bPP5: Propylene block copolymer (MFR: 8.7 g / 10 min, melting point: 160 ° C.)
(2) Propylene / α-olefin random copolymer rPP1: Propylene / α-olefin random copolymer (MFR: 7 g / 10 min, melting point: 133 ° C., density: 910 kg / m ³ )
rPP2: Propylene-α-olefin random copolymer (MFR: 7.8 g / 10 min, melting point: 131 ° C., density: 910 kg / m ³ )
rPP3: Propylene-α-olefin random copolymer (melting point: 138 ° C.)
rPP 4: Propylene-α-olefin random copolymer (polymer using metallocene catalyst, MFR: 10 g / 10 min, melting point: 118 ° C.)
(3) Homopolypropylene hPP1: Homopropylene (MFR: 6.8 g / 10 min, melting point: 162 ° C., density 910 kg / m ³ )
(4) Polyethylene PE1: Linear low density polyethylene (MFR: 2.3 g / 10 min, melting point: 126 ° C., density 937 kg / m ³ )
(5) butylene / propylene copolymer BPR1: MFR: 9 g / 10 min, melting point: 58 ° C.
BPR 2: MFR: 9 g / 10 min, melting point: 100 ° C.
(6) Additives AB: Slip agent-containing anti-blocking agent

2. Measurement and evaluation method (1) MFR of propylene-based block copolymer
According to JIS K7210, it measured on conditions of 230 ° C and a 2.16 kg load.

(2) Melting | fusing point of a propylene-type block copolymer The temperature of the largest melting peak of the DSC curve of a propylene-type block copolymer obtained using DSC (differential scanning calorimeter) was made into melting | fusing point.

(3) Young's modulus From the packaging film for bread obtained in Examples and Comparative Examples, strip-shaped test pieces (length: 200 mm, width: 15 mm) in the flow direction (MD) and width direction (TD), respectively I cut it out.
Next, in accordance with JIS K 7127: 1999, using a tensile tester (tensilon universal tester RTC-1225 manufactured by ORIENTEC Co., Ltd.), measurement temperature 23 ± 3 ° C., measurement humidity 50 ± 5% RH, tensile speed (cross Young's modulus of each test piece was measured under the condition of head speed 5 mm / min, distance between chucks 100 mm, and Young's modulus T _{1 in} the MD direction and TD direction of bread packaging film obtained in Examples and Comparative Examples. The Young's modulus T ₂ was used.

(4) Impact strength 100 mm wide test pieces were cut out from the bread packaging films obtained in the examples and the comparative examples. Next, using a film impact tester manufactured by Toyo Seiki Seisaku-sho, the impact strength of each test piece is measured with a hemisphere having a tip shape of 0.5 inch under an atmosphere of 5 ± 2 ° C. and 50 ± 5% RH. did.

(5) Piercing Strength From the bread packaging films obtained in the examples and the comparative examples, test pieces each having a width of 60 mm and a length of 200 to 300 mm were cut out. Subsequently, it measured on conditions of 23 ± 2 ° C. and 50 ± 5% RH according to JIS Z1707: 1997 using Tensilon RTC-1225 manufactured by ORIENTEC Co., Ltd.

(6) Tear strength Using a light load tear tester manufactured by Toyo Seiki Seisakusho, for bread obtained in Examples and Comparative Examples under the conditions of a measurement temperature of 23 ± 3 ° C. and a measurement humidity of 50 ± 5% RH The tear strength in the TD direction of the packaging film was measured.

(7) Coefficient of static friction (tan θ)
The coefficient of static friction (tan θ) of the surface on the heat seal layer side of the bread packaging film obtained in Examples and Comparative Examples was measured by the following method 1 (gradient method) using a slip tester.
(Method 1)
Prepare two sheets of bread packaging film cut into a size of 50 mm × 75 mm (hereinafter referred to as bread packaging films 1 and 2), and heat sealing layer side of one of the above-mentioned bread packaging films 1 is on top It fixed to the inclination board so that it might become. Next, a friction body whose bottom (size is 41 mm × 26 mm) is made of brass was fixed at the center of the surface of the other side of the bread packaging film 2 opposite to the heat seal layer side. Next, a weight was attached on the friction body such that the weight applied to the bread packaging film 2 from the friction body was 150 g. Subsequently, the heat seal layer side surfaces of the two packaging films 1 and 2 for bread were overlapped. Next, the inclined plate was inclined at a speed of 1 ° / sec, and the value of tan θ was determined from the angle θ when the upper packaging film for bread 2 slipped.

(8) Evaluation of Filling Property of Bread Using the packaging film for bread obtained in Examples and Comparative Examples, the heat sealing layer is on the inside of the bag, and the size of 12 cmm in length x 12 cm in width x 22 cm in height A bottom gusset bag was made. Next, the gusset bag was opened and held, and commercially available five-piece bread was baked in an oven toaster with upper and lower heaters for 3 minutes at a power of 1000 W for stacking five sheets. The size of the five-layered bread was measured to be 11.5 cm long × 10.5 cm wide × 13 cm high. Next, the piled bread of the above-mentioned gusset bag was dropped at a time from the top of the opening. It evaluated by the presence or absence of the tear of the gusset bag at that time.
○: no tearing of the bag occurs ×: tearing of the bag occurs

[Examples 1 to 6 and Comparative Examples 1 to 4]
Each package was co-extrusion molded in the layer configuration shown in Tables 1 and 2 to produce bread packaging films, and each evaluation was performed. The coextrusion molding conditions are as follows.
Multilayer extruder: 60 mmφ multilayer T-die extruder (L / D = 27, manufactured by Screw Seiki Co., Ltd.)
Extrusion set temperature: 200 to 270 ° C, processing speed: 34 m / min

  When the bread packaging film of the example was used, it was possible to suppress the occurrence of tearing of the bag when the bag was filled with bread. That is, it was found that when the bread packaging film of the example is used, the filling property of the bread and the productivity of the product can be improved.

100 Packaging film for bread 101 core layer 103 heat seal layer 105 surface layer

Claims (14)

Bread packaging film for packaging bread,
A core layer comprising polyolefin,
A heat seal layer provided on one side of the core layer;
Equipped with
The tear strength in the TD direction of the bread packaging film is 4.0 N / mm or more, which is measured using a light load tear tester at a measurement temperature of 23 ± 3 ° C. and a measurement humidity of 50 ± 5% RH. ,
A packaging film for bread having a static friction coefficient (tan θ) of the surface on the heat seal layer side of the packaging film for bread, which is measured by the following method 1 (inclination method) using a slip tester, which is 2.0 or less.
(Method 1)
Two sheets of the bread packaging film cut into a size of 50 mm × 75 mm (hereinafter referred to as bread packaging films 1 and 2) are prepared, and the heat sealing layer side of the bread packaging film 1 of one sheet is prepared Fix it to the inclined plate so that it is on top. Next, a friction body whose bottom (size is 41 mm × 26 mm) is made of brass is fixed to the center of the surface of the other side of the bread packaging film 2 opposite to the heat seal layer side. A weight is attached on the body so that the weight applied to the bread packaging film 2 from the friction body is 150 g. Next, the heat seal layer side surfaces of the two bread packaging films 1 and 2 are overlapped. Next, the inclined plate is inclined at a speed of 1 ° / sec, and the value of tan θ is determined from the angle θ when the upper packaging film 2 for bread has slipped out. In the bread packaging film according to claim 1,
MD direction of the packaging film for bread according to JIS K 7127: 1999 measured at a measurement temperature of 23 ± 3 ° C., a measurement humidity of 50 ± 5% RH, and a tensile speed of 5 mm / min using a tensile tester. Young's modulus _{T 1} and TD direction of the sum of Young modulus _{T 2 (T 1 + T 2} ) packaging films for bread or less 1500MPa or more 700 MPa. In the bread packaging film according to claim 1 or 2,
MD direction of the packaging film for bread according to JIS K 7127: 1999 measured at a measurement temperature of 23 ± 3 ° C., a measurement humidity of 50 ± 5% RH, and a tensile speed of 5 mm / min using a tensile tester. bread packaging film Young's modulus _{T 1} of the is equal to or less than 800MPa or more 300 MPa. The packaging film for bread according to any one of claims 1 to 3.
A packaging film for bread, wherein the impact strength of the packaging film for bread is 3.0 kg · cm or more and 8.0 kg · cm or less, which is measured under the conditions of 5 ± 2 ° C. and 50 ± 5% RH. The packaging film for bread according to any one of claims 1 to 4.
A packaging film for bread, wherein the piercing strength of the packaging film for bread is 1.5 N or more and 3.5 N or less, which is measured under the conditions of 23 ± 2 ° C. and 50 ± 5% RH in accordance with JIS Z1707: 1997. The packaging film for bread according to any one of claims 1 to 5,
A packaging film for bread, wherein the polyolefin comprises a propylene-based block copolymer. In the bread packaging film according to claim 6,
The package for breads whose content of the said propylene-type block copolymer contained in the said core layer is 50 mass% or more and 100 mass% or less, when content of the said polyolefin contained in the said core layer is 100 mass%. the film. In the bread packaging film according to claim 6 or 7,
Pan according to JIS K 7210, wherein the melt flow rate (MFR) of the propylene-based block copolymer measured under conditions of 230 ° C. and 2.16 kg load is 0.5 g / 10 min or more and 20 g / 10 min or less Packaging film. The packaging film for bread according to any one of claims 1 to 8.
A packaging film for bread further comprising a surface layer on the surface of the core layer opposite to the surface on which the heat seal layer is provided. In the bread packaging film according to claim 9,
The packaging film for bread, the surface layer comprising one or more selected from homopolypropylene, a propylene-based block copolymer, and a random copolymer of propylene and an α-olefin having 2 to 10 carbon atoms. The packaging film for bread according to any one of claims 1 to 10.
The packaging film for bread, wherein the heat seal layer is provided to be in direct contact with the one surface of the core layer. The packaging film for bread according to any one of claims 1 to 11,
The packaging film for bread according to claim 1, wherein the heat seal layer comprises one or more selected from homopolypropylene and a random copolymer of propylene and an α-olefin having 2 to 10 carbon atoms. The packaging film for bread according to any one of claims 1 to 12,
A packaging film for bread, wherein the bread comprises bread.   A bread package using the bread packaging film according to any one of claims 1 to 13.

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