JP2019085541A - Resin composition for easily openable heat seal material, easily openable heat seal material, packaging material and package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for an easy-to-open heat-sealing material capable of realizing an easy-to-open heat-sealing material having an excellent balance between easy-to-open and processable performance. The resin composition for an easy-to-open heat-sealing material of the present invention is a resin composition used for an easy-to-open heat-sealing material, and is a polypropylene-based resin (A) and ethylene / unsaturated carboxylic acid. An unsaturated ester-based random copolymer (B), the above-mentioned polypropylene-based resin (A) in the above-mentioned resin composition, and the above-mentioned ethylene / unsaturated carboxylic acid / unsaturated ester-based random copolymer (B). When the total is 100% by mass, the content of the polypropylene-based resin (A) is 1% by mass or more and 50% by mass or less, and the ethylene / unsaturated carboxylic acid / unsaturated ester-based random copolymer (B). Content is 50% by mass or more and 99% by mass or less. [Selection diagram] None

Description

  The present invention relates to a resin composition for a heat sealable material, a heat sealable material, a packaging material and a package.

  One of the functions required for a package such as a packaging bag is easy-openability. By giving the package easy-openability, the contents can be taken out without breaking the package. Generally as a method of providing easy-openability to a package, the easy-open heat seal material is used.

  As a technique regarding such an easily openable heat sealing material, the thing of patent document 1 and 2 is mentioned, for example.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2013-136151) discloses an easily openable laminated film obtained by sequentially laminating a base material layer, an intermediate layer, and a sealant layer, and the sealant layer is made of polyethylene resin, ethylene · Thermoplastic resin A selected from the group consisting of methacrylic acid copolymer resin and polypropylene resin, and thermoplastic resin B selected from polybutene-1, polypropylene or ethylene-propylene random copolymer, thermoplastic resin A / The layer which has a sea island structure which consists of a resin composition which contains by mass ratio of thermoplastic resin B = 70/30 to 97/3, and in which the domain consisting of the thermoplastic resin B is dispersed in the thermoplastic resin A phase. The ratio of the major axis to the minor axis of the domain cross section is: major axis / minor axis = 14 to 30, and the thickness of the sealant layer is 3 to 15 μm. And wherein, easily openable laminated film is described.

  Patent Document 2 (Japanese Patent Laid-Open No. 2009-96155) describes a multilayer laminated film having a seal layer (A) and a base material layer (B), wherein 10 to 50 parts by weight of high density polyethylene and 50 to 90 parts by weight A base layer (B) consisting of a block or random copolymer of ethylene / propylene is laminated on one or two or more layers on a seal layer (A) consisting of a mixture of polypropylene of part; The multilayer laminated film is characterized in that the layer thickness of the layer) is 1 μm to 20 μm and the layer thickness of the base material layer (B) is 20 μm to 100 μm.

JP, 2013-136151, A JP, 2009-96155, A

In recent years, from the viewpoint of reducing the cost of an easily openable heat seal material used for a package, a resin composition for an easy openability heat seal material capable of obtaining a thin heat seal layer while satisfying the easy openability. Is required.
However, according to the study of the present inventors, when the thin heat seal layer is formed using the conventional resin composition for easy-to-open heat sealing material, the easy-opening property of the obtained packaging material is deteriorated. I found out.
That is, it was revealed that there is room for improvement in the conventional resin composition for easy-openability heat sealing material in terms of the balance of performance of easy-openability and processability.

  The present invention has been made in view of the above circumstances, and provides a resin composition for an easy-openable heat seal material that can realize an easy-open heat seal material excellent in the balance of easy-openability and processability performance. is there.

  The present inventors diligently studied to achieve the above object. As a result, when the polypropylene resin (A) is blended in a specific amount to the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) excellent in processability, the performance of easy opening and processability It has been found that the balance can be improved, and the present invention has been achieved.

  That is, according to the present invention, the following resin composition for easy-to-open heat seal material, easy-to-open heat seal material, packaging material and package are provided.

[1]
A resin composition used for an easy-open heat sealing material,
A polypropylene resin (A) and an ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B),
The polypropylene-based resin (A) when the total of the polypropylene-based resin (A) and the ethylene / unsaturated carboxylic acid / unsaturated ester-based random copolymer (B) in the resin composition is 100% by mass. Easy to open, the content of which is 1% by mass to 50% by mass, and the content of the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) is 50% by mass to 99% by mass Heat sealing material resin composition.
[2]
In the resin composition for an easily openable heat sealing material as described in the above [1],
The melt flow rate (MFR) of the polypropylene-based resin (A) is 1.0 g / 10 minutes to 50 g / 10 minutes, which is measured under the conditions of 230 ° C. and 2160 g load according to JIS K 7210: 1999.
The melt flow rate (MFR) of the above-mentioned ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) is 1.0 g which is measured under the conditions of 190 ° C. and 2160 g load according to JIS K 7210: 1999. The resin composition for easily openable heat sealing materials which is / 10 minutes or more and 50 g / 10 minutes or less.
[3]
In the resin composition for easily opening heat sealing material according to the above [1] or [2],
The polypropylene-based resin (A) is easily selected one or more selected from homopolypropylene, a random copolymer of propylene and ethylene or an α-olefin having 4 to 20 carbon atoms, and a propylene-based block copolymer Resin composition for openable heat sealing material.
[4]
In the resin composition for easily opening heat sealing material according to the above [1] or [2],
The resin composition for easily openable heat sealing materials in which the said polypropylene resin (A) contains a propylene-type block copolymer.
[5]
In the resin composition for an easily openable heat sealing material according to any one of the above [1] to [4],
The content of the constitutional unit derived from the above-mentioned ethylene contained in the above-mentioned ethylene · unsaturated carboxylic acid · unsaturated ester random copolymer (B) is 50 mass% or more and 98.9 mass% or less, Easy openability wherein the content of the structural unit derived from the carboxylic acid is 0.1% by mass to 20% by mass and the content of the structural unit derived from the unsaturated ester is 1% by mass to 30% by mass Resin composition for heat sealing materials.
[6]
In the resin composition for an easily openable heat sealing material according to any one of the above [1] to [5],
The resin composition for easily openable heat sealing materials in which the said unsaturated carboxylic acid in the said ethylene and unsaturated carboxylic acid and unsaturated ester random copolymer (B) contains (meth) acrylic acid.
[7]
In the resin composition for an easily openable heat sealing material according to any one of the above [1] to [6],
The resin composition for easily openable heat sealing materials in which the said unsaturated ester in the said ethylene and unsaturated carboxylic acid and unsaturated ester random copolymer (B) contains (meth) acrylic acid ester.
[8]
The easily openable heat sealing material comprised with the resin composition for easily openable heat sealing materials as described in any one of said [1] thru | or [7].
[9]
A substrate layer,
A heat seal layer provided on at least one surface of the base material layer and comprising the easily openable heat seal material according to the above [8];
Packaging material.
[10]
In the packaging material according to the above [9],
The packaging material whose thickness of the said heat seal layer is 20 micrometers or less.
[11]
In the packaging material according to the above [9] or [10],
The heat seal layer has a sea-island structure,
Packaging in which at least the polypropylene resin (A) is present in the island phase in the sea-island structure, and the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) is present in the sea phase in the sea-island structure Material.
[12]
The package using the packaging material as described in any one of said [9] thru | or [11].

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition for easy-openability heat sealing materials which can implement | achieve the easy-openability heat sealing material excellent in the performance balance of easy-openability and workability can be provided.

  Hereinafter, embodiments of the present invention will be described. In addition, "X-Y" of a numerical range represents X or more and Y or less unless there is particular notice. Also, in the present embodiment, "(meth) acrylic" means acrylic, methacrylic or both acrylic and methacrylic.

1. Resin Composition for Easy-to-Open Heat Sealing Material (P) The resin composition for easy-to-open heat sealing material (P) according to the present embodiment (hereinafter also referred to as a resin composition (P)) has easy-openability. A resin composition used for a heat seal material, which comprises a polypropylene resin (A) and an ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B).
And, in the resin composition (P), 100 mass of the total of the above-mentioned polypropylene resin (A) and the above-mentioned ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) in the resin composition (P) %, The content of the polypropylene resin (A) is 1% by mass to 50% by mass, and the content of the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) is 50% % Or more and 99% by mass or less.
In addition, the lower limit value of the content of the polypropylene resin (A) in the resin composition (P) is preferably 2% by mass or more, more preferably 3% by mass or more, from the viewpoint of making easy openability better. More preferably, it is 5% by mass or more, particularly preferably 6% by mass or more. The upper limit value of the content of the polypropylene resin (A) in the resin composition (P) is preferably 40% by mass or less, more preferably 30% by mass or less, particularly preferably from the viewpoint of making the processability better. It is 20 mass% or less.
The lower limit of the content of the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) in the resin composition (P) is preferably 60 mass% from the viewpoint of making the processability better. % Or more, more preferably 70% by mass or more, particularly preferably 80% by mass or more. The upper limit of the content of the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) in the resin composition (P) is preferably 98% by mass from the viewpoint of improving the easy opening property. The content is more preferably 97% by mass or less, particularly preferably 95% by mass or less.

As described above, according to the study of the present inventors, when the thin heat seal layer is formed using the conventional resin composition for easy-to-open heat sealing material, the easy-opening property of the obtained packaging material is deteriorated. I found that I would do it.
Moreover, the present inventors discovered that it was difficult for the conventional resin composition for easy-to-open heat seal materials to form a thin easy-to-open heat seal layer stably. That is, the present inventors have found that there is room for improvement in the conventional resin composition for an easily openable heat sealing material, from the viewpoint of the balance between the easy openability and the processability.

The present inventors diligently studied to achieve the above object. As a result, by blending the polypropylene resin (A) to a content within the above range with respect to the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) excellent in processability, It has been found that even when a thin heat-seal layer is formed, good easy-openability can be obtained, resulting in the present invention.
By compounding the polypropylene resin (A) to the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) so as to have a content within the above range, good processability is obtained It is considered that the adhesion of the heat sealing material obtained can be reduced and the easy-openability can be improved.
That is, according to the resin composition (P) which concerns on this embodiment, the easily openable heat sealing material excellent in the performance balance of easy openability and thin film processability is realizable.

  In the resin composition (P) according to the present embodiment, the total content of the content of the polypropylene resin (A) and the content of the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) is When the total amount of the resin composition (P) is 100% by mass, it is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more Preferably it is 95 mass% or more. The openability of the packaging material obtained when the total content of the content of the polypropylene resin (A) and the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) is within the above range The performance balance of processability can be further improved.

  Hereinafter, each component which comprises resin composition (P) is demonstrated.

<Polypropylene resin (A)>
Examples of the polypropylene resin (A) according to this embodiment include homopolypropylene, a random copolymer of propylene and ethylene or an α-olefin having 4 to 20 carbon atoms (hereinafter also referred to as random polypropylene), and propylene. Examples include a block copolymer (hereinafter also referred to as block polypropylene) and the like.
The polypropylene resin (A) according to the present embodiment may be used singly or in combination of two or more.
Among these, block polypropylene is preferable as the polypropylene resin (A) from the viewpoint of being able to obtain an easily openable heat seal material having a more excellent performance of easy opening and processability.
In addition, from the viewpoint of being able to obtain an easily openable heat seal material further excellent in the balance of easy openability and processability, as the polypropylene resin (A), ethylene, unsaturated carboxylic acid, unsaturated ester random The polypropylene resin (A) incompatible with the copolymer (B) is preferable.

  In the random polypropylene according to the present embodiment, examples of ethylene or an α-olefin having 4 to 20 carbon atoms include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 1- Dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 4-methyl-1-pentene and the like can be mentioned. Among these, ethylene or an α-olefin having 4 to 10 carbon atoms is preferable, ethylene or 1-butene is more preferable, and ethylene is more preferable. The content of the structural unit derived from α-olefin in random polypropylene is preferably 10 mol% or less, and 5 mol% or less, when the content of all structural units in random polypropylene is 100 mol%. It is more preferable that the content be 2 mol% or less. One of these α-olefins may be used alone, or two or more thereof may be used in combination.

As the block polypropylene according to the present embodiment, for example, a block copolymer of propylene and ethylene or an α-olefin having 4 to 20 carbon atoms can be used. Examples of ethylene or α-olefins having 4 to 20 carbon atoms include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene 1-octadecene, 1-eicosene, 4-methyl-1-pentene and the like. Among these, ethylene or an α-olefin having 4 to 10 carbon atoms is preferable, ethylene or 1-butene is more preferable, and ethylene is more preferable. The content of the structural unit derived from the α-olefin in the block polypropylene is preferably 1 mol% or more and 30 mol% or less, when the content of all the structural units in the block polypropylene is 100 mol%, and 2 It is more preferable that it is mol% or more and 20 mol% or less. One of these α-olefins may be used alone, or two or more thereof may be used in combination.
Further, the block polypropylene according to the present embodiment is a group consisting of a polymer part composed of at least one polypropylene selected from the group consisting of homopropylene and random polypropylene, ethylene and an α-olefin having 4 to 20 carbon atoms. And a copolymer including a polymer part composed of at least one olefin selected from

  In the present embodiment, from the viewpoint of further improving the flowability and the moldability, the melt of the polypropylene resin (A) according to the present embodiment, which is measured under the conditions of 230 ° C. and 2160 g load according to JIS K 7210: 1999. The flow rate (MFR) is preferably 1.0 g / 10 minutes to 50 g / 10 minutes, more preferably 3.0 g / 10 minutes to 45 g / 10 minutes, and 5.0 g / 10 minutes. More preferably, it is 40 g / 10 min or less.

  The melting point of the polypropylene resin (A) according to the present embodiment is preferably 120 ° C. or more and 180 ° C. or less, more preferably 130 ° C. or more and 175 ° C. or less, still more preferably 140 ° C. or more and 170 ° C. or less. When the melting point of the polypropylene-based resin (A) is at least the lower limit value, the balance of the easy-openability, the heat resistance, the handleability, and the like of the heat seal material to be obtained can be improved. Moreover, heat sealing property of the heat sealing material obtained can be made more favorable for the melting point of a polypropylene resin (A) to be below the said upper limit.

  The manufacturing method of a polypropylene resin (A) is not specifically limited, It can manufacture by a well-known method. Moreover, you may use what is marketed as a polypropylene resin (A).

<Ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B)>
The ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) according to this embodiment copolymerizes ethylene, at least one unsaturated carboxylic acid, and at least one unsaturated ester. Polymer. As the ethylene-unsaturated carboxylic acid-unsaturated ester random copolymer (B), a copolymer containing ethylene, an unsaturated carboxylic acid and an unsaturated ester can be exemplified.

Examples of the unsaturated carboxylic acid constituting the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) according to the present embodiment include acrylic acid, methacrylic acid, 2-ethyl acrylic acid, crotonic acid, and the like. Maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, monomethyl maleate, monoethyl maleate and the like can be mentioned.
Among these, the above-mentioned unsaturated carboxylic acid is at least one selected from acrylic acid and methacrylic acid from the viewpoints of productivity, hygiene and the like of ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B). Is preferred. These unsaturated carboxylic acids may be used alone or in combination of two or more.

  Examples of the unsaturated ester constituting the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) according to this embodiment include vinyl esters such as vinyl acetate and vinyl propionate; (meth) acrylic acid Methyl, ethyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, n-butyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate Meta) acrylic acid ester etc. are mentioned. These unsaturated esters may be used alone or in combination of two or more. Among these, (meth) acrylic acid esters are preferable, and at least one selected from isobutyl (meth) acrylate and n-butyl (meth) acrylate (that is, butyl (meth) acrylate) is preferable.

In the present embodiment, as the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B), ethylene (meth) acrylic acid / (meth) acrylic acid ester copolymer is more preferable, and ethylene · (meth) Particularly preferred is at least one selected from (meth) acrylic acid / (meth) acrylic acid isobutyl copolymer and ethylene / (meth) acrylic acid / (meth) acrylic acid n-butyl copolymer.
In the present embodiment, “(meth) acrylic acid” means acrylic acid, methacrylic acid or acrylic acid and methacrylic acid, and as ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer Examples are ethylene-acrylic acid-acrylic acid ester copolymer, ethylene-methacrylic acid-acrylic acid ester copolymer, ethylene-acrylic acid-methacrylic acid ester copolymer, ethylene-methacrylic acid-methacrylic acid ester copolymer, etc. It can be illustrated.
The ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) according to the present embodiment may be used alone or in combination of two or more.

In the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) according to this embodiment, the content of the structural unit derived from ethylene is preferably 50% by mass or more and 98.9% by mass or less. Preferably it is 65 to 94.5 mass%, More preferably, it is 75 to 91.5 mass%.
When the content of the structural unit derived from ethylene is equal to or more than the above lower limit value, the heat resistance, the mechanical strength and the like of the obtained heat seal material can be further improved. Moreover, transparency, a softness | flexibility, adhesiveness, etc. of the heat sealing material obtained as the content of the structural unit derived | led-out from ethylene is below the said upper limit can be made more favorable.

In the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) according to the present embodiment, the content of the structural unit derived from the unsaturated carboxylic acid is preferably 0.1% by mass or more and 20% by mass The following content is more preferably 0.5% by mass to 10% by mass, and still more preferably 0.5% by mass to 5% by mass.
When the content of the structural unit derived from the unsaturated carboxylic acid is equal to or more than the above lower limit, the transparency, the flexibility, the adhesiveness, and the like of the obtained heat sealing material can be further improved. Moreover, the processability of a resin composition (P) can be made more favorable as content of the structural | constituent unit derived | led-out from unsaturated carboxylic acid is below the said upper limit.

In the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) according to the present embodiment, the content of the structural unit derived from the unsaturated ester is preferably 1% by mass or more and 30% by mass or less, more preferably Preferably it is 3 to 25 mass%, More preferably, it is 5 to 15 mass%.
When the content of the structural unit derived from the unsaturated ester is equal to or more than the above lower limit value, the transparency, the flexibility, the adhesiveness, and the like of the heat sealing material obtained can be further improved. Moreover, the processability of a resin composition (P) can be made more favorable as content of the structural unit derived | led-out from unsaturated ester is below the said upper limit.

  In the present embodiment, from the viewpoint of further improving the flowability and moldability, the ethylene / unsaturated carboxylic acid / unmodified according to the present embodiment is measured under the conditions of 190 ° C. and 2160 g load according to JIS K 7210: 1999. The melt flow rate (MFR) of the saturated ester random copolymer (B) is preferably 1.0 g / 10 minutes to 50 g / 10 minutes, and is 3.0 g / 10 minutes to 40 g / 10 minutes. And more preferably 5.0 g / 10 minutes or more and 30 g / 10 minutes or less.

  The method for producing the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) according to the present embodiment is not particularly limited, and can be produced by a known method. For example, it can be obtained by radical copolymerization of each polymerization component under high temperature and high pressure. Further, as the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B), those commercially available may be used.

<Other ingredients>
The resin composition (P) according to the present embodiment is not limited to the polypropylene resin (A) and the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B), as long as the effects of the present invention are not impaired. You may contain an ingredient. The other components are not particularly limited. For example, plasticizers, antioxidants, UV absorbers, antistatic agents, surfactants, colorants, light stabilizers, foaming agents, lubricants, crystal nucleating agents, crystallization Accelerator, crystallization retarder, catalyst deactivator, thermoplastic resin, thermosetting resin, inorganic filler, organic filler, impact modifier, slip agent, crosslinking agent, crosslinking aid, tackifier, Silane coupling agent, processing aid, mold release agent, hydrolysis inhibitor, heat resistant stabilizer, anti blocking agent, antifogging agent, flame retardant, flame retardant auxiliary, light diffusing agent, antibacterial agent, mildew agent, dispersion Agents, other resins, etc. can be mentioned. The other components may be used alone or in combination of two or more.

<Method of Preparing Resin Composition (P)>
The method for preparing the resin composition (P) is not particularly limited. For example, the polypropylene resin (A) and an ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) are dry blended and mixed. Method of preparing by melting; method of preparing by melt mixing a polypropylene resin (A) and an ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) with an extruder etc .; can do. From the viewpoint of improving the dispersibility of the polypropylene resin (A) in the ethylene · unsaturated carboxylic acid · unsaturated ester random copolymer (B), the polypropylene resin (A) and the ethylene · unsaturated carboxylic acid · unsaturated The method of preparing by melt-mixing a saturated ester random copolymer (B) with an extruder etc. is preferable.

2. Easy-to-open heat seal material The easily-openable heat seal material according to the present embodiment is composed of the resin composition (P) for easy-open heat seal material according to the present embodiment.
The easily openable heat sealing material according to the present embodiment is composed of the resin composition (P) for easily openable heat sealing material, and thus is excellent in the balance of easy openability and processability.

  The manufacturing method of the easily openable heat sealing material according to the present embodiment is not particularly limited, and a conventionally known manufacturing method can be used. For example, a press molding method, an extrusion molding method, an injection molding method, a compression molding method, a cast A molding method, a calendar molding method, an inflation molding method, etc. can be used.

3. Packaging Material The packaging material according to the present embodiment includes, for example, a base material layer, and a heat seal layer provided on at least one surface of the base material layer and comprising the easily openable heat sealing material according to the present embodiment And.
Since the packaging material which concerns on this embodiment is equipped with the heat seal layer which consists of an easily openable heat sealing material which concerns on this embodiment, it is excellent in the performance balance of easy opening property and workability. Therefore, it can be suitably used for applications where easy openability is required.

  In the packaging material according to the present embodiment, the thickness of the heat seal layer made of the heat sealing material according to the present embodiment is, for example, 1 μm or more and 20 μm or less, preferably 2 μm or more and 15 μm or less, more preferably 3 μm or more 12 μm or less. Since the easily openable heat sealing material according to the present embodiment is excellent in processability, such a thin heat sealing layer can be realized, and in particular, it can be suitably used for easy peel application.

In the packaging material according to the present embodiment, the heat seal layer preferably has a sea-island structure from the viewpoint of further improving the performance balance of easy-openability and processability. When the heat seal layer has a sea-island structure, at least a polypropylene resin (A) is present in the island phase in the sea-island structure, and an ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) in the sea phase in the sea-island structure ) Is preferably present.
The sea-island structure in the heat seal layer can be observed by, for example, a scanning electron microscope (SEM) image or a transmission electron microscope (TEM) image.

The base material layer which concerns on this embodiment is a layer provided in order to improve characteristics, such as the handleability of a packaging material, mechanical characteristics, electroconductivity, heat insulation, heat resistance, moisture resistance, etc. more. As the base material layer, for example, resin films such as olefin resin, polyester, polyamide, ethylene / vinyl alcohol copolymer, polyvinyl chloride, polyvinylidene chloride, polystyrene, acrylonitrile / butadiene / styrene copolymer (ABS), polycarbonate and the like A metal foil; paper; an aluminum vapor deposited polyester film, an aluminum vapor deposited polypropylene film, a silica vapor deposited polyester film, a plastic film having a metal surface or a ceramic surface such as an alumina vapor deposited polyester film; It is also good.
These may be used alone or in combination of two or more. These may be uniaxially or biaxially stretched.

The substrate layer may be surface-treated to improve adhesion to the heat seal layer. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coating treatment, etc. may be performed.
The thickness of the base material layer is preferably 1 μm to 200 μm, more preferably 2 μm to 100 μm, and still more preferably 5 μm to 80 μm.
Although the shape of a base material layer is not specifically limited, For example, shapes, such as a sheet | seat and a film, are mentioned.

The packaging material according to the present embodiment may be composed of only the base material layer and the heat seal layer, or from the viewpoint of imparting various functions to the packaging material, layers other than the base material layer and the heat seal layer ( Hereinafter, it may also be referred to as another layer). Examples of other layers include foam layers, metal layers, inorganic layers, gas barrier resin layers, antistatic layers, hard coat layers, adhesive layers, antireflective layers, antifouling layers and the like. One other layer may be used alone, or two or more layers may be used in combination.
Here, the adhesive layer is a layer provided to enhance the adhesion between the layers.

The packaging material according to the present embodiment may be uniaxially or biaxially stretched at any rate, as needed.
Further, the shape of the packaging material according to the present embodiment is not particularly limited, but a film or a sheet is preferable.

  The packaging material which concerns on this embodiment can be suitably used as a packaging material used, for example, for packaging foodstuffs, such as confectionery and meat, pharmaceuticals, industrial goods, daily necessities, cosmetics etc., and packaging of foodstuffs and medicines. It can be particularly suitably used as a material.

The manufacturing method of the packaging material which concerns on this embodiment is not specifically limited, The shaping | molding method generally used can be applied about a thermoplastic resin. For example, it can be carried out by a known method using a T-die extruder or an inflation molding machine.
For example, after a film made of the resin composition (P) according to the present embodiment is formed, a dry lamination method of bonding a base material layer using an adhesive or the like; a resin composition (P Method of extruding and laminating a): A method of extruding and laminating a substrate layer on a film made of the resin composition (P) according to the present embodiment can be used.
Here, since the resin composition (P) according to the present embodiment is excellent in processability, a thin heat seal is used in the extrusion lamination molding method in which the resin composition (P) is melt-extruded and laminated on the base material layer. Layers can be formed with high productivity. Therefore, from the viewpoint of productivity, the packaging material according to the present embodiment is preferably manufactured by the extrusion laminating method.

4. Package The package according to the embodiment uses the packaging material according to the embodiment.
The package according to the present embodiment is, for example, one in which the contents are contained in the packaging bag itself or the packaging bag used for the purpose of containing the contents of food, medicine, industrial goods, daily necessities and the like. Moreover, the package which concerns on this embodiment may use the packaging material which concerns on this embodiment for the one part, and may use the packaging material which concerns on this embodiment for the whole package.
Although the form of the package which concerns on this embodiment is not specifically limited, For example, a three-sided bag, a four-sided bag, a pillow bag, a gusset bag, a stick bag etc. are mentioned. The package according to the present embodiment can be used, for example, as a food packaging bag, a pharmaceutical packaging bag, an industrial packaging bag, a daily packaging bag, and the like. In particular, it can be suitably used as a food packaging bag.

  As mentioned above, although embodiment of this invention was described, these are the illustrations of this invention, and various structures other than the above can also be employ | adopted.

  EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

  The details of the components used for preparation of the resin composition (P) are as follows.

<Polypropylene resin (A)>
Homo PP1: homopolypropylene (manufactured by Prime Polymer Co., Ltd., trade name: F113G, MFR (230 ° C., 2160 g load): 3.0 g / 10 min, density: 910 kg / m ³ , melting point: 157 ° C.)
Random PP2: random polypropylene (manufactured by Prime Polymer Co., Ltd., trade name: F227D, MFR (230 ° C., 2160 g load): 7.0 g / 10 min, density: 910 kg / m ³ , melting point: 138 ° C.)
Block PP3: block polypropylene (manufactured by Prime Polymer Co., Ltd., trade name: J715M, MFR (230 ° C., 2160 g load): 9.0 g / 10 min, density 910 kg / m ³ , melting point 165 ° C.)
Block PP4: block polypropylene (manufactured by Prime Polymer Co., Ltd., trade name: J707G, MFR (230 ° C., 2160 g load): 30 g / 10 min, density: 910 kg / m ³ , melting point: 165 ° C.)

<Ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B)>
EMAA · BA: ethylene / methacrylic acid / butyl acrylate copolymer (ethylene content: 88.5 mass%, methacrylic acid content: 4.0 mass%, butyl acrylate content: 7.5 mass%, MFR (190 ° C, 2160 g load): 14 g / 10 min, density: 930 kg / m ³ )

<Other copolymers>
EMAA 1: ethylene / methacrylic acid copolymer (ethylene content: 96.0% by mass, methacrylic acid content: 4.0% by mass, MFR (190 ° C., 2160 g load): 7.0 g / 10 minutes)
EMAA 2: ethylene / methacrylic acid copolymer (ethylene content: 91.0% by mass, methacrylic acid content: 9.0% by mass, MFR (190 ° C., 2160 g load): 8.2 g / 10 minutes)
EMAA 3: ethylene / methacrylic acid copolymer (ethylene content: 90.0% by mass, methacrylic acid content: 10.0% by mass, MFR (190 ° C., 2160 g load): 35 g / 10 min)
Ionomer 1: Ionomer of ethylene / methacrylic acid copolymer (metal ion: Na ion, MFR (190 ° C., 2160 g load): 3.0 g / 10 min, degree of neutralization: 35%)
LLDPE 1: Linear low density polyethylene (MFR (190 ° C., 2160 g load): 11 g / 10 min), density: 940 kg / m ³ )
HDPE 1: High density polyethylene (MFR (190 ° C, 2160 g load): 5.2 g / 10 min), density: 965 kg / m ³ )
TPX1: Polymethylpentene (MFR (230 ° C, 2160 g load): 100 g / 10 min)
APL 1: cyclic olefin resin ((MFR (260 ° C., 2160 g load): 80 g / 10 min))

Example 1
(1) Base Layer As the base layer, a laminated film of OPP film (20 μm) / LDPE film (15 μm) / alumina-deposited PET film (12 μm) was used.
An undercoat layer was provided between the OPP film and the LDPE film.
(2) Preparation of Packaging Material An anchor coat layer is applied to the PET surface of the above-mentioned laminated film on the alumina-deposited PET film (12 μm) side using an extrusion coating apparatus, and then the resin temperature under the die is 315 ° C. Using the resin composition (P), a 10 μm thick heat seal layer was extrusion coated on the above-mentioned anchor coat layer to obtain a packaging material.
Here, resin composition (P) was prepared by melt-mixing each component by the mixing | blending shown in Table 1 using a 30 mm diameter co-axial twin-screw extruder.
In addition, the obtained packaging material was stored for 2 days in a 40 degreeC atmosphere thermostat, and the process which solidifies an anchor coat layer was performed.
The following evaluation was performed about the obtained resin composition (P) and a packaging material. The results are shown in Table 1.

<Evaluation>
(1) Processability evaluation The processability of the resin composition (P) was evaluated by the following method.
When a heat seal layer with a thickness of 10 μm is extrusion-coated on the above base layer using a resin composition (P) under the conditions of a processing speed of 200 m / min, the resin melt film is broken or the end of the resin melt film The product which was able to extrusion-coat the resin composition (P) on the substrate layer with the same width and the same thickness without shaking the part was evaluated as "○", and the same width and the same thickness The thing which could not carry out extrusion coating of resin composition (P) on a base material layer by this, was evaluated as "x".

(2) Easy openability evaluation First, the obtained packaging material was cut out into A4 size. Next, a heat sealer (manufactured by Tester Sangyo Co., Ltd.) was used to produce a three-sided sealed bag of the cut-out packaging material. The heat seal conditions were heat seal temperature: 110 to 130 ° C., heat seal pressure: 0.2 MPa, and heat seal time: 0.5 seconds.
Next, the obtained three-way sealed bag was opened using a human hand, and easy openability (peelability and state of peel interface) was evaluated based on the following criteria.
-Evaluation of removability Evaluation was performed by five panelists, and those evaluated as good by all five were evaluated as "◎", those evaluated by one to four as good as "○", all five as poor. Each thing was evaluated as "x".
Good: Those that could open the bag without stress with appropriate force. Poor: The bag could not be opened if it was not strong enough and it is clearly difficult to open; when opening the bag, the substrate layer Evaluation of the state of the peeling interface which corresponds to any of the broken ones; the heat sealing property of the mouth of the bag is obviously weak and the mouth opens immediately and that the mouth of the bag can not be heat sealed; : The skin feels loose and fluff is not observed at the interface after peeling, and can be peeled off neatly ○: The hair is not observed at the interface after peeling, but the skin feeling is rough is observed ×: After peeling Fluff is observed at the interface of

[Examples 2 to 4 and Comparative Examples 1 to 9]
A resin composition (P) and a packaging material were produced in the same manner as in Example 1 except that the composition shown in Table 1 was used, and the same evaluation as in Example 1 was performed. The obtained results are shown in Table 1, respectively.

The resin compositions (P) and the packaging materials of Examples 1 to 4 were excellent in the balance of easy-openability and processability. Moreover, the sea island structure was observed by the scanning electron microscope (SEM) image in the heat seal layer obtained by the resin composition (P) of Examples 1-4.
On the other hand, the resin compositions (P) and the packaging materials of Comparative Examples 1 to 9 were inferior in the balance of easy-openability and processability.

Claims (12)

A resin composition used for an easy-open heat sealing material,
A polypropylene resin (A) and an ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B),
The polypropylene-based resin (A) when the total of the polypropylene-based resin (A) and the ethylene / unsaturated carboxylic acid / unsaturated ester-based random copolymer (B) in the resin composition is 100% by mass Easy opening whose content of the ethylene, unsaturated carboxylic acid, unsaturated ester random copolymer (B) is 50% by mass to 99% by mass. Heat sealing material resin composition. In the resin composition for easy-openability heat sealing material according to claim 1,
The melt flow rate (MFR) of the polypropylene-based resin (A) is 1.0 g / 10 minutes to 50 g / 10 minutes, which is measured under conditions of 230 ° C. and 2160 g load in accordance with JIS K 7210: 1999,
The melt flow rate (MFR) of the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) is 1.0 g measured in accordance with JIS K 7210: 1999 at 190 ° C. under a load of 2160 g. The resin composition for easily openable heat sealing materials which is / 10 minutes or more and 50 g / 10 minutes or less. In the resin composition for easily openable heat sealing materials according to claim 1 or 2,
The polypropylene-based resin (A) is one or more selected from homopolypropylene, random copolymers of propylene and ethylene or α-olefins having 4 to 20 carbon atoms, and propylene-based block copolymers. Resin composition for openable heat sealing material. In the resin composition for easily openable heat sealing materials according to claim 1 or 2,
The resin composition for easily openable heat sealing materials in which the said polypropylene resin (A) contains a propylene-type block copolymer. In the resin composition for easily openable heat sealing materials according to any one of claims 1 to 4,
The content of the structural unit derived from the ethylene contained in the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) is from 50% by mass to 98.9% by mass, and the above unsaturated Easy openability wherein the content of the structural unit derived from carboxylic acid is 0.1% by mass to 20% by mass, and the content of the structural unit derived from the unsaturated ester is 1% by mass to 30% by mass Resin composition for heat sealing materials. In the resin composition for easily openable heat sealing materials according to any one of claims 1 to 5,
The resin composition for easily openable heat sealing materials in which the said unsaturated carboxylic acid in the said ethylene and unsaturated carboxylic acid and unsaturated ester random copolymer (B) contains (meth) acrylic acid. In the resin composition for easily openable heat sealing materials according to any one of claims 1 to 6,
The resin composition for easily openable heat sealing materials in which the said unsaturated ester in the said ethylene * unsaturated carboxylic acid * unsaturated ester type random copolymer (B) contains (meth) acrylic acid ester.   The easily openable heat sealing material comprised with the resin composition for easily openable heat sealing materials as described in any one of Claims 1 thru | or 7. A substrate layer,
A heat seal layer provided on at least one surface of the base material layer and comprising the easily openable heat seal material according to claim 8;
Packaging material. In the packaging material according to claim 9,
The packaging material whose thickness of the said heat seal layer is 20 micrometers or less. In the packaging material according to claim 9 or 10,
The heat seal layer has a sea-island structure,
Package in which at least the polypropylene resin (A) is present in the island phase in the sea-island structure, and the ethylene / unsaturated carboxylic acid / unsaturated ester random copolymer (B) is present in the sea phase in the sea-island structure Material.   A package using the packaging material according to any one of claims 9 to 11.