JP2005335118A - Easily tearable laminated film and bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a re-sealable and easily tearable laminated film suitable for a bag capable of preventing mischief such as opening or the like, and the bag using it and effectively preventing mischief. <P>SOLUTION: The easily tearable laminated film is constituted by laminating a base material film (II) having easily tearable properties on the thermoplastic resin layer (A) of a coextrusion multilayered film (I), which is formed by successively laminating the thermoplastic resin layer (A), a pressure-sensitive adhesive resin layer (B) and a heat sealing resin layer (C), so that the flow direction of the coextrusion multilayered film (I) becomes parallel to a tearing direction. The bag is formed by superposing the films one upon another so that the heat sealing resin layers (C) come into contact with each other to heat-seal the end parts of the film and providing two rows of heat sealing parts parallel to the tearing direction of the base material film (II) to the part becoming an opening part by tearing of the folded film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laminate film and a bag that can be easily torn and can be resealed when the heat-sealed portion is opened and the opened portion exhibits good adhesiveness.

  The conventional re-sealable multilayer film is a flexible packaging material comprising a base layer, a pressure-sensitive adhesive layer adjacent to the base layer, and a skin layer (heat seal layer) covering the pressure-sensitive adhesive layer. Each surface of the packaging material has a coefficient of friction so that the material can be machined in the packaging machine, and the material is sealed against itself by the sealing jaws of the packaging machine and during normal handling Has an initial bond strength that will remain closed, but can be packaged with a seal that can be easily pulled apart by hand for opening, and this skin layer will break when the seal is pulled apart. Adhesive adhesive is exposed at the surface of the seal area, so that the packaging material is sealed against itself in the area of the seal by the application of hand pressure only to reclose the package Ur and flexible packaging material are known (e.g., see Patent Document 1.).

  Furthermore, as a multilayer film that can be resealed, hydrogenation of a surface resin layer (A) containing a thermoplastic resin (a) and a rubbery block copolymer containing a styrene block and a diene block The adhesive resin layer (B) containing the product (b1) and the tackifier (b2), and the heat seal resin layer (C) containing the thermoplastic resin (c) are (A) / (B) / (C) is a multilayer film laminated in the order of heat sealing the heat seal resin layer (C) and the heat seal resin layer (C) and a heat sealable thermoplastic resin layer. Then, when peeled off, the heat seal resin layer (C) and the adhesive resin layer (B) are broken and the adhesive resin layer (B) and the surface resin layer (A) are separated from each other. B) Viscosity that can be resealed in the heat seal area Multilayer film exposed in the state is also known (e.g., see Patent Document 2.).

  Each of these bags using multilayer films is heat-sealed by overlapping the heat seal layers of the multilayer films so that they are in contact with each other, forming a bag shape, placing the article in the bag, and further heating the article entry port. By sealing and sealing, it is possible to form a package in which the heat seal portion can be easily peeled off by hand when opened. The heat seal layer of these bags breaks when the seal is pulled away and the adhesive adhesive is exposed at the surface of the seal area so that the packaging material is against itself in the area of the seal by the application of hand pressure only. It can be sealed to reclose the package. However, since these bags can be resealed, there is a problem that tampering (tampering) such as resealing and returning to the display shelf after opening the bags on the display shelf is easy.

  As a bag that can prevent such mischief, the heat-sealing resin layer of the film having resealability and easy tearability is overlaid so that it is heat-sealed at the edge of the film, and by tearing A bag having two rows of heat-sealed portions parallel to the tearing direction at the opening portion, for example, the heat-sealing resin layers are stacked so that the heat-sealing resin layers are in contact with each other, heat-sealing is performed at the edge of the film, and the tearing direction After creating a bag with parallel openings and filling with articles, etc., perform two heat seals in parallel at the edge of the opening and at a distance from the film, and if necessary, Further, a bag formed by creating a tear notch at the bag end between two rows of heat seal portions is conceivable. This bag has no margin for peeling because the edge of the film is heat-sealed. Therefore, to open the bag, first tear the bag from one end to the other end between the two heat seals, and then peel off the heat seal part using the torn part as a margin. Therefore, there is an advantage that a torn part is easily recognized and mischief cannot be performed. However, in order to obtain this bag, it is essential to use a film having resealability and easy tearability, and the resealable multilayer film described in Patent Documents 1 and 2 is easily tearable. Since it does not have property, it is not preferable. In addition, the re-sealable multilayer film described in Patent Documents 1 and 2 has a pressure-sensitive adhesive layer and a pressure-sensitive resin layer (B), and therefore imparts good easy tearability by uniaxial stretching or the like. Is usually difficult.

Japanese National Publication No. 04-502588 (page 2-3) JP2003-175567 (page 4-7)

  An object of the present invention is to provide a film having an easy tear property as well as a resealability suitable for a bag capable of preventing the tampering, and a bag effective for preventing a tampering using the film. is there.

  As a result of intensive studies, the inventors of the present invention have disclosed a surface resin layer (A) containing the thermoplastic resin (a) of the multilayer film coextruded multilayer film described in Patent Document 2 and capable of being resealed. On top of this, a film made by laminating a base film having easy tearability so that the flow direction and tear direction of the coextruded multilayer film are parallel to each other has excellent resealability and good tearability. It is suitable as a film for packaging bags that can prevent the mischief, and is suitable for a packaging bag that can prevent the mischief, and a bag using this can effectively prevent mischief As a result, the present invention has been completed.

  That is, in the present invention, the thermoplastic resin layer (A), the pressure-sensitive adhesive resin layer (B), and the heat seal resin layer (C) are laminated in the order of (A) / (B) / (C). On the thermoplastic resin layer (A) of the coextruded multilayer film (I) having resealability, the base film (II) having easy tearability is torn along with the flow direction of the coextruded multilayer film (I). It is an object of the present invention to provide an easily tearable laminate film characterized by being laminated so that the directions are parallel to each other.

  In the present invention, the heat-sealing resin layer (C) of the easily tearable laminate film is superposed so as to be in contact with each other and heat-sealed at the end of the film, and a base material is formed in a portion that becomes an opening portion by tearing. A bag comprising two rows of heat seal portions parallel to the tearing direction of the film (II) is provided.

  The easily tearable laminate film of the present invention is suitable as a film for bags having excellent resealability and good easy tearability and preventing the above-mentioned mischief. Effectively prevent mischief.

  The coextruded multilayer film (I) having resealability used for the easily tearable laminate film of the present invention comprises a thermoplastic resin layer (A), a pressure-sensitive adhesive resin layer (B), and a heat seal resin layer (C). And (A) / (B) / (C) are films having a multilayered resin layer laminated by the coextrusion method in order, and heat-sealed by overlapping so that the heat-seal resin layer (C) is in contact Thereafter, when the film is peeled off, the pressure-sensitive adhesive resin layer (B) is a multilayer film exposed in a re-sealable state at the heat seal portion.

  As such a co-extrusion multilayer film (I), for example, the heat seal resin layer (C) is broken when the heat seal resin layer (C) is overlapped and heat sealed so as to be in contact and then peeled off. At the same time, the pressure-sensitive adhesive resin layer (B) and the heat-seal resin layer (C) are separated from each other, and the pressure-sensitive adhesive resin layer (B) is exposed in an adhesive state that can be resealed at the heat-seal portion. Sealable coextruded multilayer film (1), heat-seal resin layer (C) breaks and pressure-sensitive adhesive resin layer (B) peels off due to cohesive failure, and can be resealed at the heat-sealed part Resealable coextruded multilayer film (2), pressure-sensitive adhesive resin layer (B) and heat-seal resin layer (C) that are exposed at the same time, and thermoplastic resin layer (A) and pressure-sensitive adhesive resin layer (B) layer peels off, pressure sensitive adhesion Resealable co-extruded multilayer film (3) where the resin layer (B) is exposed in an adhesive state that can be resealed at the heat seal portion, and the like. Resin coextrusion multilayer films (1) and (3) are preferred because of their strong and stable adhesive strength.

  As the resealable coextruded multilayer film (1), for example, when the heat seal portion is peeled off, the heat seal resin layer (C) breaks and the pressure sensitive adhesive resin layer (B) and the heat seal are peeled off. Since the interlayer of the resin layer (C) needs to be peeled off, the interlayer adhesive strength between the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C) (tensile speed of 300 mm in accordance with JIS Z-1707) (Strength measured in minutes / min., Hereinafter the same) is 2 to 20 N / 15 mm, preferably 2 to 18 N / 15 mm, and the interlayer adhesion between the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) Less than the strength, preferably the difference in interlayer adhesion strength between the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) is 5 N / 15 mm or more, and the thickness of the heat seal resin layer (C) Is 0.6 to 10 μm, preferably 1 The coextruded multilayer film is 10 to 10 μm, more preferably 1 to 6 μm, and the total of the resin layers (A), (B), and (C) is 20 to 100 μm, preferably 20 to 60 μm.

  As the resealable coextruded multilayer film (2), for example, when the heat seal portion is peeled off, the heat seal resin layer (C) is broken and the pressure sensitive adhesive resin layer (B) is cohesive failure Therefore, the cohesive failure strength of the pressure-sensitive adhesive resin layer (B) (strength measured at a tensile speed of 300 mm / min according to JIS Z-1707. The same applies hereinafter) is 10 to 30 N /. 15 mm, preferably 13 to 28 N / 15 mm, the interlayer adhesive strength between the thermoplastic resin layer (A) and the pressure sensitive adhesive resin layer (B), the pressure sensitive adhesive resin layer (B) and the heat seal resin layer (C ) Is greater than the cohesive failure strength of the pressure-sensitive adhesive resin layer (B), preferably 25 N / 15 mm or more, more preferably 25 to 40 N / 15 mm, and the heat seal resin layer (C). The thickness is 0. 30 .mu.m, preferably at 2 to 20 [mu] m, the total of the resin layer (A) and (B) (C) is 20 to 100 [mu] m, with preference given to coextruded multilayer films of 20 to 60 [mu] m.

  Further, as the resealable coextruded multilayer film (3), when the heat seal portion is peeled off, the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C) break and the thermoplastic resin. A multi-layered resin layer in which the layer between the layer (A) and the pressure-sensitive adhesive resin layer (B) is peeled off and the pressure-sensitive adhesive resin layer (B) is exposed in a resealable state at the heat seal portion. The interlayer adhesive strength between the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) is 2 to 23 N / 15 mm, preferably 2 to 18 N / 15 mm, and the pressure-sensitive adhesive resin layer (B ) And the heat-sealing resin layer (C), and the difference between the pressure-sensitive adhesive resin layer (B) and the heat-sealing resin layer (C) is preferably 5 N / 15 mm or more. Moreover, the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer ( ) Is 3 to 25 μm, preferably 3.5 to 23 μm, more preferably 4 to 20 μm, and the total of the resin layers (A), (B) and (C) is 20 to 100 μm, preferably 20 to 20 μm. A co-extruded multilayer film of 60 μm can be mentioned. In addition, the thickness of the heat seal resin layer (C) is generally 0.6 to 10 μm, preferably 1 to 10 μm, and more preferably 1 to 6 μm.

  In addition, in the coextruded multilayer film (I) used in the present invention, it is important to appropriately select a combination of resin layers in order to achieve a target interlayer adhesive strength. It is necessary to consider that the interlayer adhesive strength also changes. Even if the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C) are used in a combination that is relatively excellent in adhesiveness, for example, it is composed of a metal neutralized product of an ethylene- (meth) acrylic acid copolymer. In the case of the heat seal resin layer, if the thickness is as small as 0.1 to 0.5 μm, the interlayer adhesive strength with the pressure-sensitive adhesive resin layer (B) is greatly reduced, and conversely if it is as large as 20 to 30 μm, the interlayer The adhesive strength takes a large value without decreasing.

  The thermoplastic resin layer (A) of the coextruded multilayer film (I) used in the present invention may be a resin layer containing the thermoplastic resin (a) as a main component, and is a resin layer having a single layer structure. Alternatively, a resin layer having a multilayer structure may be used. Examples of the thermoplastic resin (a) used herein include olefin resins such as ethylene resins and propylene resins, styrene resins, ester resins, and amide resins and imide resins when oxygen barrier properties are to be maintained. Examples thereof include resins, saponified resins of ethylene-vinyl acetate copolymer, and the like, and are used as a single layer constituting resin or a multilayer constituting resin by mixing two or more kinds.

  Examples of the ethylene resin include ethylene resins such as very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE); Ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate- Ethylene copolymers such as maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA); and ethylene-acrylic acid copolymer Of metal neutralized polymer, ethylene-methacrylic acid copolymer Genus in the hydrate, and the like.

  Examples of the propylene resin include propylene homopolymers, copolymers of propylene and other α-olefins such as ethylene and butene, and the copolymers include random copolymers and block copolymers. Either can be used. Examples of the propylene homopolymer include isotactic polypropylene, syndiotactic polypropylene, and attack polypropylene. Among these, isotactic polypropylene is preferable.

  These thermoplastic resins (a) are preferably ethylene-based resins and propylene-based resins because they are inexpensive and excellent in moldability. In particular, in the case of the resealable coextruded multilayer film (3), the interlayer adhesive strength between the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) is appropriate and easily peeled off. There is little roughness of the delamination surface of the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) when the seal portion is peeled off, and the reseal strength is high when opening and resealing are repeated. Therefore, ethylene- (meth) acrylic acid copolymers such as ethylene-acrylic acid copolymer (EAA) and ethylene-methacrylic acid copolymer (EMAA) and / or metal neutralized products thereof are preferred, and ethylene- ( A metal neutralized product of a (meth) acrylic acid copolymer is particularly preferred. As the metal neutralized product of the ethylene- (meth) acrylic acid copolymer, for example, at least 10 mol%, preferably 10 to 60 mol% of the carboxyl group is a metal ion such as sodium or zinc. What is summed up.

  Further, for the thermoplastic resin layer (A), an antifogging agent, an antistatic agent, a thermal stabilizer, a nucleating agent, an antioxidant, a lubricant, an antiblocking agent, a release agent, and an ultraviolet absorber are optionally provided. In addition, components such as a colorant may be added as long as the object of the present invention is not impaired.

  The pressure-sensitive adhesive resin layer (B) of the co-extruded multilayer film (I) used in the present invention may be a resin layer containing a thermoplastic resin that can be melted and extruded and has pressure-sensitive adhesiveness. Although not particularly limited, the amorphous olefin resin (b1) is an essential component, and if necessary, a rubbery thermoplastic resin (b2) and / or a tackifier (b3), other olefin resins (b4) And a resin layer containing a rubber-like thermoplastic resin (b2) and / or a tackifier (b3) as essential components. Specific examples include a resin layer made of only an amorphous olefin resin (b1), a resin layer made of an amorphous olefin resin (b1) and another olefin resin (b4), an amorphous olefin resin ( a resin layer comprising b1) and a rubbery thermoplastic resin (b2), a resin layer comprising an amorphous olefin resin (b1) and a tackifier (b3), an amorphous olefin resin (b1) and rubbery heat A resin layer comprising a plastic resin (b2) and a tackifier (b3), an amorphous olefin resin (b1), a rubbery thermoplastic resin (b2), a tackifier (b3), and another olefin resin (b4) And a resin layer made of a rubbery thermoplastic resin (b2) and a tackifier (b3).

  The amorphous olefin resin (b1) may be a resin layer having an adhesiveness with an amorphous olefin resin having an α-olefin-derived component content of 3 or more carbon atoms of 50 mol% or more, Among these, an amorphous olefin-based resin having a content of an α-olefin derived from 3 to 20 carbon atoms is preferably 50 mol% or more, and a content of an α-olefin derived component having 3 to 12 carbon atoms is 80 mol. % Of an amorphous olefin resin is more preferable, and an amorphous olefin resin having a content of an α-olefin-derived component having 3 to 4 carbon atoms of 80 mol% or more is most preferable.

  Moreover, as said amorphous olefin resin (b1), even if it is a homopolymer of an α-olefin having 3 or more carbon atoms, for example, two or more α-olefins having 3 or more carbon atoms are used. The copolymer may be a copolymer of an α-olefin having 3 or more carbon atoms and another monomer, or a mixture thereof. Specific examples of the amorphous olefin-based resin (b1) include homopolymers such as amorphous polypropylene and amorphous poly-1-butene, 50 mol% or more of 1-butene and other α-olefins, For example, a copolymer with propylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-dexene, etc., 50 mol% or more of propylene and other α-olefins, for example, 1 And copolymers with -butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-dexene, etc., and amorphous propylene homopolymer, amorphous 1-butene Homopolymer, amorphous propylene-1-butene copolymer having a propylene-derived component content of 50 mol% or more, amorphous 1-butene-propylene copolymer having a 1-butene-derived component content exceeding 50 mol% Coalescence etc. An amorphous 1-butene-propylene copolymer having a 1-butene-derived component content of more than 60 mol% is particularly preferred.

  The number average molecular weight of the amorphous olefin resin (b1) is preferably 100,000 to 500,000, and when the amorphous olefin resin (b1) is a copolymer, Either a copolymer or a block copolymer may be used, but a random copolymer is preferred.

  Commercially available products that can be used as the amorphous olefin-based resin (b1) include, for example, “Retax” from Huntsman, Inc., “Cataloy” from Sun Allomer, “Ubetak” from Ube Lexellen, Ube Industries, Ltd. “CAP” and “Tough Selenium” from Sumitomo Chemical Co., Ltd.

  In the present invention, the amorphous property of the amorphous olefin resin (b1) means that the sample is 5 mg from a differential scanning calorimeter (DSC) at a rate of temperature increase of 10 ° C./min from 20 ° C. to 230 ° C. When measured, no melting peak is observed, and the heat of fusion of the maximum peak in the endothermic curve is 0.7 J / g or less.

  The amorphous olefin resin (b1) has a high molecular weight and is sticky, and resin pellets tend to adhere to each other. Therefore, clogging occurs in the piping section for delivery to the extruder, and adhesion to the meter when blending. However, there is a problem in raw material handling such that accurate formulation is difficult, but in order to improve raw material handling, the content of other olefin resin (b4), for example, an α-olefin derived component having 3 or more carbon atoms It is preferable to use together olefin resin other than the said amorphous olefin resin (b1) whose is 50 mol% or more.

  A method of using the amorphous olefin resin (b1) and the other olefin resin (b4) in combination is not particularly limited. For example, the amorphous olefin resin (b2) and another olefin resin (b4). It is preferable to melt and knead the mixture with a twin-screw extruder or the like, or coat the amorphous olefin resin (b2) with another olefin resin (b4) and then pelletize it. The melt index (measured at 230 ° C. according to MI, JIS K-7210) of the pellets is preferably 0.1 to 30 g / 10 minutes because flow disturbance is unlikely to occur. More preferably, it is 5 to 20 g / 10 minutes. The weight ratio (b1) / (b4) when the amorphous olefin resin (b2) and the other olefin resin (b4) are used in combination is preferably 99/1 to 60/40, and 97/3 to 70. / 30 is more preferable.

  The pressure-sensitive adhesive resin layer (B) is a resin layer having a good balance between pressure-sensitive adhesiveness and heat-resistant resealability (resealability at 5 to 90 ° C., for example, under heating). A resin layer containing the amorphous olefin resin (b1) and the rubbery thermoplastic resin (b2) is preferable, and among them, the amorphous olefin resin (b1) and the rubbery thermoplastic resin (b2) A resin layer containing the tackifier (b3) is particularly preferable. In this case, the other olefin resin (b4) can also be used in combination for improving the raw material handling of the amorphous olefin resin (b1).

  When the pressure-sensitive adhesive resin layer (B) is a resin layer containing an amorphous olefin resin (b1) and a rubbery thermoplastic resin (b2) as necessary, these (b1) and ( The use ratio of b2) is preferably such that the weight ratio (b1) / (b2) is 20/80 to 100/0, and in particular, the balance between pressure-sensitive adhesiveness and heat-resistant resealability is good. Since it becomes a resin layer, it is more preferable that the weight ratio (b1) / (b2) is a ratio of 30/70 to 80/20.

  Further, the pressure-sensitive adhesive resin layer (B) is a resin layer containing a non-crystalline olefin resin (b1) and a rubber-like thermoplastic resin (b2) and a tackifier (b3) as necessary. In some cases, the use ratio of (b1), (b2) and (b3) is such that the weight ratio (b1) / (b2) is 20/80 to 100/0 and the weight ratio (b1 + b2) / (b3) Is preferably in a ratio of 50/50 to 98/2. In particular, since the resin layer has a good balance between adhesiveness and heat resealability, the weight ratio (b1) / (b2) is 30/70. It is more preferable that the ratio is ˜80 / 20 and the weight ratio (b1 + b2) / (b3) is 60/40 to 90/10.

  In the pressure-sensitive adhesive resin layer (B), the rubber thermoplastic resin (b2) and the tackifier (b3) are also used when the rubber thermoplastic resin (b2) and the tackifier (b3) are used in combination. ) Is preferably kneaded and pelletized.

  The rubbery thermoplastic resin (b2) is not particularly limited as long as it is a rubbery thermoplastic resin. For example, a styrene-butadiene block copolymer (SB), a hydrogenated product thereof, styrene-butadiene- Styrene block copolymer (SBS), its hydrogenated product, styrene-isoprene-styrene block copolymer (SIS), its hydrogenated product, styrene-isoprene block copolymer (SI), its hydrogenated product styrene-ethylene -Rubber block copolymer containing styrene block such as propylene block copolymer (SEP) and its hydrogenated product; ethylene-propylene copolymer (EP), ethylene-butene-1 copolymer (EB) ), Ethylene-octene copolymer (EO), propylene-butadiene copolymer (PB), ethylene- Acid vinyl copolymer (EVA) rubber copolymer the ethylene was obtained as an essential component as such, and the like.

  Among these rubbery thermoplastic resins (b2), a rubbery block copolymer containing a styrene block and a diene block, and its hydrogenated product are preferred, have low odor, gel, fish eye, fluid disturbance, etc. Since a co-pressed film having no appearance defect and capable of continuous production for a long time and having good resealability is obtained, a complete and / or partially hydrogenated product of styrene-butadiene block copolymer (SB), styrene -Complete and / or partial hydrogenation of butadiene-styrene block copolymer (SBS), complete and / or partial hydrogenation of styrene-isoprene-styrene block copolymer (SIS), styrene-isoprene block copolymer (SI) complete and / or partially hydrogenated styrene block and diene block More preferred is a complete and / or partially hydrogenated block copolymer of styrene-butadiene block copolymer (SB) (HSBR), styrene-butadiene-styrene block copolymer (SBS). Complete hydrogenated product (SEBS), Partial hydrogenated product of styrene-butadiene-styrene block copolymer (SBS) (SBBS), Hydrogenated product of styrene-isoprene-styrene block copolymer (SIS) (styrene-ethylene- Propylene-styrene block copolymer (SEPS) is most preferred.

  The hydrogenation ratio of the hydrogenated product of the rubbery copolymer is usually 10 to 100 mol%, and preferably 30 to 100 mol%. Further, the melt index (measured at 190 ° C. in accordance with MI, JIS K-7210) is preferably 2 to 30 g / 10 minutes because flow disturbance is unlikely to occur.

  Examples of the tackifier (b3) include resins having an adhesive property at room temperature, such as natural resins and synthetic resins, such as natural resin rosin, polymerized rosin, hydrogenated rosin, glycerinster rosin, pentaerythritol, and the like. Rosin resins; Terpene resins such as terpenes, aromatic modified terpenes, terpene phenols, hydrogenated terpenes; petroleum resins such as aliphatic petroleum resins, aromatic petroleum resins, hydrogenated alicyclic petroleum resins; And liquid polybutadiene, liquid polyisoprene at room temperature, and polyisobutylene liquid at room temperature. Among them, rosin resin, terpene resin, and petroleum resin are preferable.

  The other olefin-based resin (b4) may be an olefin-based resin other than the amorphous olefin-based resin (b1) in which the content of the α-olefin-derived component having 3 or more carbon atoms is 50 mol% or more. For example, propylene-based resin, 1-butene-based resin, trimethylpentene-1 (TPX) and the like can be mentioned. Among them, propylene-based resin is preferable because it has heat resistance, a high melting point, and is easily available.

  If necessary, various additives such as softeners, oils (mineral oils), stabilizers (antioxidants, etc.), surfactants, liquid paraffin, etc. are added to the adhesive resin layer (B). Also good.

  The heat-seal resin layer (C) of the coextruded multilayer film (I) used in the present invention may be any heat-sealable resin layer containing the thermoplastic resin (c), and the thermoplastic resin (herein used) Examples of c) include olefin resins such as ethylene resins and propylene resins, styrene resins, and ester resins.

  Examples of the ethylene resin used as the thermoplastic resin (c) in the heat seal resin layer (C) include the ethylene resins exemplified as the thermoplastic resin (a). Examples of the propylene resin include propylene and Copolymers with other α-olefins, such as propylene-ethylene copolymers and propylene-butene copolymers, can be mentioned. As these propylene-based copolymers, any of random copolymers and block copolymers can be used, but random copolymers are preferred.

  Examples of the ester resin used as the thermoplastic resin (c) in the heat seal resin layer (C) include ester resins such as polyethylene terephthalate and polybutylene terephthalate, and polyethylene terephthalate is particularly preferable.

  When the coextruded multilayer film (I) used in the present invention is heat-sealed so that the heat-seal resin layer (C) of this film is in contact with it, the pressure-sensitive adhesive resin layer (B) is peeled off when peeled off. Are exposed in a resealable state at the heat seal portion, and as such a resealable film, as described above, the resealable coextruded multilayer films (1), (2), (3 ) And the like.

  In the case of the resealable coextruded multilayer film (1), the heat seal resin layer (C) of the resealable coextruded multilayer film (1) was overlaid and heat sealed, and then peeled off. In this case, it is necessary to select the resin configuration of the heat seal resin layer (C) so that the pressure sensitive adhesive resin layer (B) and the heat seal resin layer (C) are easily separated from each other.

  In the resealable coextruded multilayer film (1), the combination of the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C) can be easily separated as described above. A combination having an adhesive strength of 2 to 20 N / 15 mm and smaller than the interlayer adhesive strength of the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) can be mentioned as a preferable one. This interlayer adhesive strength is a strength that can maintain the function as a multilayer film, and is a strength that allows relatively easy delamination. To do this, the heat seal resin layer (C) has a moderate adhesiveness with the pressure-sensitive adhesive resin layer (B), and the adhesive strength between these layers is reduced to about 2 to 20 N / 15 mm. What is necessary is just to select a sealing resin layer and to combine with a pressure sensitive adhesive resin layer (B). As such a heat seal resin layer, for example, ethylene- (meth) acrylic acid such as ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA) as the thermoplastic resin (c). A resin layer using a copolymer and / or a metal neutralized product thereof is preferable, and a resin layer using a metal neutralized product of an ethylene- (meth) acrylic acid copolymer is a pressure-sensitive adhesive resin. The pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (when the heat seal portion is peeled off) when the interlayer adhesive strength between the layer (B) and the heat seal resin layer (C) becomes appropriate and peels easily. The delamination surface of C) is less rough, and the resealing strength when opening and resealing is high is particularly preferable.

  In the resealable coextruded multilayer film (1), the thermoplastic resin layer (A) may be a resin layer containing the thermoplastic resin (a) as a main component, but is a pressure-sensitive adhesive resin. It is necessary that the interlayer adhesive strength with the layer (B) is a resin layer that is larger than the interlayer adhesive strength between the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C). For this reason, as the thermoplastic resin (a) used in the thermoplastic resin layer (A), the interlayer adhesive strength between the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) is a pressure-sensitive adhesive resin layer ( It is preferable to select an appropriate resin in consideration of being larger than the interlayer adhesive strength between B) and the heat seal resin layer (C). For example, olefin resins such as ethylene resins and propylene resins, styrene resins Examples thereof include resins, ester resins, ethylene resins having adhesiveness with ester resins, styrene resins or ethylene resins having adhesiveness with styrene resins. Of these, ethylene resins and propylene resins are preferable, and ethylene resins are particularly preferable.

  In the resealable coextruded multilayer film (1), the ethylene resin contained in the thermoplastic resin layer (A) includes the above-described ethylene resins, styrene resins and ester resins as the thermoplastic resin (a). Can be used. Examples of the propylene resin include the ethylene resins described above as the thermoplastic resin (a), such as a propylene-ethylene copolymer and a propylene-butene copolymer. Further, in order to increase the interlayer adhesion strength between the surface resin layer (A) and the adhesive resin layer (B), an adhesive resin, for example, a resin obtained by graft polymerization of maleic anhydride or the like onto an olefin, or the aforementioned tackifier ( An appropriate amount of b3) may be added.

  In the resealable coextruded multilayer film (1), as a preferable combination of the resin layers, for example, a thermoplastic resin layer containing an ethylene resin or a propylene resin, and a carbon atom number of 3 A hydrogenated product of a rubbery block copolymer containing an amorphous olefin resin having a content of 12 α-olefin-derived components of 80 mol% or more, a styrene block and a diene block, and a tackifier (b3); A combination of a pressure-sensitive adhesive resin layer containing a propylene-based resin and a heat seal resin layer containing an ethylene- (meth) acrylic acid copolymer and / or a metal neutralized product thereof may be mentioned. Among these, what used 1 or more types of resin chosen from the group which consists of a rosin resin, a terpene resin, and petroleum resin as a tackifier (b3) in a pressure sensitive adhesive resin layer (B). Particularly preferred.

  In the case of the resealable coextruded multilayer film (2), when the heat seal resin layer (C) of this film is laminated and heat sealed so as to be in contact, the thermoplastic resin layer (A) is peeled off. And the pressure-sensitive adhesive resin layer (B) and the pressure-sensitive adhesive resin layer (B) and the heat-seal resin layer (C) are not separated, and the pressure-sensitive adhesive resin layer (B) It is necessary to select the resin configuration of the pressure-sensitive adhesive resin layer (B) so as to cause cohesive failure.

  In the resealable coextruded multilayer film (2), the resin composition that causes the cohesive failure of the pressure-sensitive adhesive resin layer (B) is hydrogenation of a rubbery block copolymer containing a styrene block and a diene block. A resin composition containing 80% by weight or more of the product can be mentioned as a preferable one.

  In the resealable coextruded multilayer film (2), preferable combinations of the resin layers include, for example, a thermoplastic resin layer containing an ethylene resin or a propylene resin, a styrene block, and a diene block. A non-crystalline olefin-based resin having a content of a hydrogenated rubber block copolymer containing 3 and α-olefin-derived components having 3 to 12 carbon atoms of 80 mol% or more, and a tackifier (b3), A pressure-sensitive adhesive resin layer containing a propylene-based resin and having a hydrogenated content of the rubbery block copolymer of 80% by weight or more, an ethylene-based resin, a propylene-based resin, a styrene-based resin, or The combination of the heat seal resin layer formed by containing ethylene-type resin which has adhesiveness with styrene-type resin or ester-type resin is mentioned. Among these, what used 1 or more types of resin chosen from the group which consists of a rosin resin, a terpene resin, and petroleum resin as a tackifier (b3) in a pressure sensitive adhesive resin layer (B). Particularly preferred.

  In the case of the resealable coextruded multilayer film (3), when the heat seal resin layer (C) of this film is overlaid and heat sealed, and then peeled off, the surface resin layer (A) and It is necessary to select the resin configuration of the surface resin layer (A) so that the layers of the adhesive resin layer (B) can be easily separated.

  In the resealable coextruded multilayer film (3), as described above, the interlayer adhesive strength is 2 as the combination in which the surface resin layer (A) and the adhesive resin layer (B) are easily separated from each other. A combination that is ˜23 N / 15 mm and that is smaller than the interlayer adhesive strength between the adhesive resin layer (B) and the heat seal resin layer (C) can be mentioned. This interlayer adhesive strength is a strength that can maintain the function as a multilayer film, and is a strength that allows relatively easy delamination. To do this, select a surface resin layer (A) that has moderate adhesiveness with the adhesive resin layer (B), and the adhesive strength between these layers is reduced to about 2 to 23 N / 15 mm. And may be combined with the adhesive resin layer (B). As such a surface resin layer, for example, an ethylene- (meth) acrylic acid copolymer such as an ethylene-acrylic acid copolymer (EAA) or an ethylene-methacrylic acid copolymer (EMAA) can be used as the thermoplastic resin (a). A resin layer containing a polymer and / or a metal neutralized product thereof is preferable, and a resin layer containing a metal neutralized product of an ethylene- (meth) acrylic acid copolymer is a surface resin layer ( Interlaminar peeling surface of surface resin layer (A) and adhesive resin layer (B) when the adhesive strength between layers A) and adhesive resin layer (B) becomes appropriate and easily peels off and the heat seal part is peeled off This is particularly preferable because of low roughness and high reseal strength when opening and resealing are repeated.

  In the resealable coextruded multilayer film (3), the heat seal resin layer (C) is an interlayer with the pressure sensitive adhesive resin layer (B) as in the resealable coextruded multilayer film (1). There is no need to select a thermoplastic resin for peeling off the resin, and there is an advantage that the degree of freedom in resin selection is high. For this reason, what is necessary is just to select suitably the said thermoplastic resin (c) contained in a heat seal resin layer (C) in consideration of the kind, shape, weight, etc. of the articles | goods with which a bag is filled. Examples of the thermoplastic resin (c) used here include olefin resins such as ethylene resins and propylene resins, ethylene resins having adhesion to styrene resins or ester resins, styrene resins, and ester resins. Examples thereof include olefin resins (including ethylene resins having adhesiveness to styrene resins or ester resins).

  In the resealable coextruded multilayer film (3), a preferable combination of the resin layers contains, for example, an ethylene- (meth) acrylic acid copolymer and / or a metal neutralized product thereof. A pressure-sensitive adhesive resin layer comprising a thermoplastic resin layer, a hydrogenated rubber block copolymer containing an amorphous olefin resin, a styrene block and a diene block, and a tackifier (b3) And a combination of heat seal resin layers containing an olefin resin. Among these, a rubber containing a non-crystalline olefin resin, a styrene block, and a diene block in which the pressure-sensitive adhesive resin layer has an α-olefin-derived component content of 3 to 12 carbon atoms of 80 mol% or more. More preferably, the pressure-sensitive adhesive resin layer contains a hydrogenated block copolymer, a tackifier (b3), and a propylene-based resin. Moreover, as the tackifier (b3), those using one or more resins selected from the group consisting of rosin resins, terpene resins and petroleum resins are particularly preferable.

  In the heat seal resin layer (C) of the coextruded multilayer film (I), an olefin resin such as an ethylene resin or a propylene resin, or an ester resin such as polyethylene terephthalate is used as the thermoplastic resin (c). When it does, since it is excellent in adhesiveness between films, stability of seal strength, etc., it is 190 ° C. for ethylene resin, 210 ° C. for propylene resin, and 260 ° C. for ester resin in accordance with JIS K-7210. Those having an MI (melt index) measured in (2) of 2 to 80 g / 10 min are preferred.

  Further, as the heat seal resin layer (C) of the co-extruded multilayer film (I), the friction coefficient of the heat seal resin layer (C) is 0. It is preferably 7 or less, especially 0.5 or less. For this reason, it is preferable to add a lubricant and an antiblocking agent to the heat seal resin layer (C) as appropriate.

  Furthermore, in the heat seal resin layer (C), if necessary, a filler, an antifogging agent, an antistatic agent, a heat stabilizer, a nucleating agent, an antioxidant, a lubricant, an antiblocking agent, a release agent, You may add a ultraviolet absorber, a coloring agent, etc. in the range which does not impair the objective of this invention.

  In the case of the resealable coextruded multilayer films (2) and (3), the layer between the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C) when the heat seal portion is peeled off. Therefore, even if additives such as lubricants and anti-blocking agents are added to the heat seal resin layer (C), there is an effect on the delamination part due to the addition of lubricants and anti-blocking agents. In addition, there is an advantage that a resealable coextruded multilayer film having a stable reseal adhesive strength without lowering the tackiness can be obtained.

  As a method for producing the coextruded multilayer film (I) used in the present invention, a resin for the thermoplastic resin layer (A) containing the thermoplastic resin (a) and an amorphous olefin resin (b1) are used. A pressure-sensitive adhesive resin layer (B) which is an essential component and further contains a rubber-like thermoplastic resin (b2) and / or a tackifier (b3), another olefinic resin (b4) and the like as necessary. Resin for heat sealing resin layer (C) containing thermoplastic resin (c) is heated and melted in separate extruders, and known methods such as coextrusion multilayer die method and feed block method are used. Examples thereof include a coextrusion method in which the layers are laminated in the order of (A) / (B) / (C) in a molten state by a method, and then coextrusion lamination is formed into a film shape by inflation, a T-die chill roll method, or the like. Further, in order to improve the adhesiveness of printing and the suitability for lamination, it is desirable to subject the thermoplastic resin layer (A) to a surface treatment.

  Examples of the surface treatment include corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, surface oxidation treatment such as ozone / ultraviolet treatment, and surface unevenness treatment such as sand blasting. is there.

  In the method for producing the coextruded multilayer film (I) as described above, when the rubber-like thermoplastic resin (b2) is used as the pressure-sensitive adhesive resin layer (B), styrene is used as the rubber-like thermoplastic resin (b2). The use of a hydrogenated rubber block copolymer containing a block and a diene block is preferable because of excellent thermal stability and stable production over a long period of time. Further, in the method for producing a multilayer film by this coextrusion method, since the pressure-sensitive adhesive resin layer (B) is sandwiched between the thermoplastic resin layer (A) and the heat seal resin layer (C), it is usually 200 ° C. There is an advantage that it is difficult to receive a direct heat history from a feed block, a die or the like heated to a high temperature exceeding 1, and that the adhesive resin layer (B) is less likely to cause gel, fish eye, fluid turbulence and the like.

  The easily tearable laminate film of the present invention comprises a base film (II) having easy tearability on the thermoplastic resin layer (A) of the coextruded multilayer film (I) and a coextruded multilayer film (I). It is a film formed by laminating so that the flow direction and the tearing direction are parallel to each other. For example, it is easy to tear on the thermoplastic resin layer (A) of the coextruded multilayer film (I) via an adhesive resin or an adhesive. A film formed by laminating a base film (II) having a property so that its tearing direction is parallel to the flow direction of the coextruded multilayer film (I). In this lamination, a film-like material such as aluminum foil may be inserted between the coextruded multilayer film (I) and the easily tearable base film (II) for lamination, or it may be easily tearable. You may use metal vapor deposition films, such as an aluminum vapor deposition film, as a base film (II) so that a metal vapor deposition surface may become a coextrusion multilayer film (I).

  The base film (II) having easy tearability is not particularly limited as long as it can be easily teared by hand, but imparts easy tearability by uniaxial stretching or biaxial stretching. Examples thereof include a thermoplastic resin film such as a stretched polypropylene film, a stretched polyethylene terephthalate film, and a stretched polyamide film. Specific examples include uniaxially stretched polypropylene films such as Mitsui Noblen ASCM manufactured by Mitsui Chemicals Platec Co., Ltd., biaxially stretched polyester films such as Emblet PC manufactured by Unitika Co., Ltd., and Uniathlon BT manufactured by Idemitsu Unitech Co., Ltd. There are axially stretched polyamide films and the like. The thickness of the base film (II) having easy tearability is usually 8 to 50 μm, preferably 10 to 40 μm.

  Examples of the method for laminating the coextruded multilayer film (I) and the easily tearable base film (II) include wet lamination, non-solvent lamination, dry lamination, extrusion lamination, and thermal lamination. Examples of the dry lamination adhesive include a polyester-polyurethane adhesive and a polyether-polyurethane adhesive.

  The bag of the present invention is laminated so that the heat-sealing resin layer (C) of the easily tearable laminate film is in contact with each other and heat-sealed at the end of the film, and the base film is formed on the portion that becomes the opening by tearing It is a bag characterized by having two rows of heat-sealed portions parallel to the tearing direction of (II), for example, by stacking easily tearable laminate films so that the heat-sealing resin layers (C) are in contact with each other, Make a bag with an opening parallel to the tearing direction by heat sealing at the edge of the film, and after filling with goods etc., at the edge of the film at the opening and at a suitable distance A bag formed by carrying out two heat seals in parallel, preferably a bag formed by creating a tear notch at the end of the bag between two rows of heat seal portions for easy tearing.

  This bag of the present invention has a heat seal at the edge of the film, so there is no allowance for tearing off, and tearing between two heat seals parallel to open or cutting with scissors After that, since it is necessary to peel off the heat-sealed portion while holding the cut portion, it can be easily determined that there is a cut portion even if it is resealed after opening.

  Examples of preferable applications for using the bag of the present invention include packaging applications for lightweight foods, stationery, cosmetics, pharmaceuticals, and the like. Bread packaging bags such as bread and confectionery bread, confectionery packaging bags such as snack confectionery and chocolate confectionery, bags for packaging processed fishery products such as delicacy, small fish and seaweed, bags for packaging processed meat products such as sliced ham, cheese, etc. Bags for packaging dairy products, wet tissue, sweat paper, fragrance, disposable diapers, etc. , Emergency plasters, and bags for packaging pharmaceutical products such as throat candy. In these applications, dozens of times are used semi-permanently and maintenance of re-sealing strength is not required, but re-sealing strength that can withstand 2 to 10 times of use is required. Such resealability is maintained in the inventive bag.

Next, the present invention will be described in more detail with reference to examples and comparative examples.
Example 1
A medium density polyethylene resin having a density of 0.93 g / cm ³ is used as the resin for the thermoplastic resin layer (A), and an amorphous polypropylene resin [manufactured by Ube Lexelene Co., Ltd.] as the resin for the pressure-sensitive adhesive resin layer (B). Ubetac UT2780] Pellets obtained by melting and kneading 20 parts by weight of propylene-ethylene copolymer (COPP) having a density of 0.90 g / cm ³ and an ethylene-derived component content of 3% by weight using a twin screw extruder (1) and a hydrogenated product having a hydrogenation rate of 40 mol% [styrene-butadiene-butylene-styrene block obtained by selectively hydrogenating a 1,2-bond portion of a styrene-butadiene-styrene block copolymer (SBS). Copolymer (SBBS)] 70 parts by weight and petroleum resin [Arakawa Chemical Co., Ltd. hydrogenated petroleum resin Alcon P-125] 29.5 parts by weight and phenolic The pellet (2) obtained by melt-kneading 0.5 parts by weight of the anti-oxidizing agent with a twin-screw extruder to be pelletized, has a weight ratio (1) / (2) of the pellets (1) and (2) of 50/50. An ethylene-methacrylic acid copolymer having a density of 0.94 g / cm ³ and a methacrylic acid-derived component content of 10% by weight as a heat seal resin layer (C) using a resin mixture (12) dry-blended at a mixing ratio of (A) layer using resin mixture (3) in which erucamide (lubricant) and natural silica (anti-blocking agent) are added to EMAA and mixed at a ratio of erucamide concentration of 1000 ppm and natural silica concentration of 2000 ppm. Extruder (50 mm diameter), (B) layer extruder (50 mm diameter), (C) layer extruder (40 mm diameter), and T-die / chill roll co-extrusion method Each is supplied to each extruder of the film manufacturing apparatus, and co-melt extrusion is performed under the conditions of a temperature of 200 to 230 ° C., a feed block and a T die temperature of 270 ° C., and three layers (A) / (B) / (C) With the constitution, a coextruded multilayer film (X1) having an average thickness of each layer of 40 μm / 5 μm / 5 μm, an overall thickness of 50 μm, and a friction coefficient of 0.6 on the surface of the heat seal resin layer (C) was obtained. The interlayer resin strength of the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) of the obtained coextruded multilayer film (X1) is 15 N / 15 mm, and the pressure-sensitive adhesive resin layer (B) and the heat seal resin The interlayer adhesion strength of (C) was 7 N / 15 mm.

  In addition, when the amorphous propylene-based resin Ubetak UT2780 5 mg was measured with a differential scanning calorimeter at a rate of temperature increase of 10 ° C./min from 20 to 230 ° C., no melting peak was observed, and the maximum peak in the endothermic curve The heat of fusion was 0.7 J / g or less.

  Biaxially stretched polyamide film substrate having easy tearability (straight cut property) on the thermoplastic resin layer (A) side of the obtained coextruded multilayer film (X1) [Uniathlon TB1000 manufactured by Idemitsu Unitech Co., Ltd., thickness 15 μm ] Were laminated by dry lamination to obtain a laminate film (Y1). At this time, as a dry lamination adhesive, a two-component curable adhesive (polyester adhesive LX63F and a curing agent KP90) manufactured by Dainippon Ink & Chemicals, Inc. was used.

Next, the two obtained laminate films (Y1) were laminated with the heat seal resin layers so that the opening portions were parallel to the tear direction, and heat sealing (upper seal bar) was performed at the three ends. The temperature was 150 ° C., the lower seal bar temperature was 30 ° C., the pressure was 2 kg / cm ² , the time was 1 second, and the seal width was 10 mm.

50 g of dried plums are put in this bag, and the end of the opening is heat-sealed and sealed, and heat-sealed again 10 mm away from the sealed part (upper seal bar temperature 150 ° C., lower seal bar temperature 30 ° C., After performing a pressure of 2 kg / cm ² , a time of 1 second, and a seal width of 10 mm), a notch for tearing was put at the end between the two heat seal parts to prepare an actual package (P-1).

  The actual packaged product (P-1) was torn by hand from the notched bag end to the opposite end, and when it was torn, the cut edge was greatly bent and it seemed to touch either of the two heat seal parts If it is judged that there is no easy tearability (NG), the number of the actual packages (P-1) that are judged to be easy tearability (NG) is examined. Nothing was judged, and all had good easy tearability.

  Subsequently, the remaining heat-sealed part of the actual package (P-1) after tearing was manually opened to expose the pressure-sensitive adhesive resin layer (B). When this exposed part was observed, in both cases, the heat seal resin layer (C) of the laminate film (Y1) was broken and the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C) were separated. The pressure-sensitive adhesive resin layer (B) was exposed in a resealable state at the heat seal part.

  Furthermore, after the films were pressure-bonded again with a finger, the seal strength (reseal strength) when opened again and the seal strength after repeated opening and resealing 10 times (repeated reseal strength) were measured. Was 2.0 N / 15 mm, and repeated reseal strength (10 times) was 1.5 N / 15 mm.

Example 2
As the resin for the thermoplastic resin layer (A), a zinc neutralized product (ionomer resin) of ethylene-methacrylic acid copolymer having a density of 0.94 g / cm ³ is used as the resin for the pressure-sensitive adhesive resin layer (B). , 80 parts by weight of an amorphous propylene-based resin (Ubetac UT2780 manufactured by Ube Rexelen Co., Ltd.) and 20 parts by weight of a propylene-ethylene copolymer (COPP) having a density of 0.90 g / cm ³ and an ethylene-derived component content of 3% by weight And a hydrogenated product of a styrene-butadiene-styrene block copolymer (SBS) [styrene-ethylene-butylene-styrene block copolymer (SEBS) )] 70 parts by weight and terpene resin [YShara Chemical Co., Ltd. YS Resin PX1150] 28.5 parts by weight and phenolic antioxidant 0.5 weight And 1 part by weight of liquid paraffin were melt-kneaded with a twin-screw extruder and pelletized (2), the weight ratio (1) / (2) between pellets (1) and (2) was 50/50 Propylene-ethylene copolymer (COPP) having a density of 0.90 g / cm ³ and an ethylene-derived component content of 3% by weight as a resin for heat seal resin layer (C) using a resin mixture (12) dry-blended at a mixing ratio Erucic acid amide (lubricant) and natural silica (anti-blocking agent) were added and mixed at a ratio of erucic acid amide concentration of 1000 ppm and natural silica concentration of 2000 ppm, except that these were used respectively. In the same manner as in Example 1, with a three-layer structure of (A) / (B) / (C), each layer having an average thickness of 37 μm / 10 μm / 3 μm and a total thickness of 50 μm To obtain a film (X2). The interlayer adhesive strength between the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) of the obtained coextruded multilayer film (X2) is 15 N / 15 mm, and the pressure-sensitive adhesive resin layer (B) and the heat seal The interlayer adhesive strength of the resin (C) was 20 N / 15 mm.

  Biaxially stretched polyethylene terephthalate film base (Embret PC manufactured by Unitika Ltd., thickness 12 μm) and aluminum foil having easy tearability on the thermoplastic resin layer (A) side of the obtained coextruded multilayer film (X2) (Thickness 9 μm) were bonded together by dry lamination to obtain a laminate film (Y2) laminated in the order of polyethylene terephthalate film substrate / aluminum foil / coextruded multilayer film (X2). At this time, as a dry lamination adhesive, a two-component curable adhesive (polyester adhesive LX63F and a curing agent KP90) manufactured by Dainippon Ink & Chemicals, Inc. was used.

  Next, a 110 × 150 mm bag was prepared in the same manner as in Example 1 except that the obtained laminate film (Y2) was used, and then the actual package (P-2) in which 50 g of dried plums was put in the same manner. Created.

  The actual packaged product (P-2) is torn by hand from the notched bag end to the opposite end, and 10 of the actual packaged product (P-2) are not easily tearable (NG). As a result of investigating whether it was judged, none was judged as having no easy tearability (NG), and all of them had good easy tearability.

  Next, the remaining heat-sealed portion of the actual package (P-2) after tearing was manually opened to expose the pressure-sensitive adhesive resin layer (B). When this exposed part was observed, both of the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C) of the laminate film (Y2) were broken, and the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin were both broken. The layers of the layer (B) were peeled off, and the pressure-sensitive adhesive resin layer (B) was exposed in a resealable state on the surface of the heat seal region.

  Furthermore, after the films were pressure-bonded again with a finger, the seal strength (reseal strength) when opened again and the seal strength after repeated opening and resealing 10 times (repeated reseal strength) were measured. Was 3.0 N / 15 mm, and repeated reseal strength (10 times) was 2.5 N / 15 mm.

Example 3
Uniaxially stretched polypropylene film base material [Mitsui Chemicals Platec Co., Ltd. Mitsui Nobrene Film ASCM, thickness which has easy tearing property on the thermoplastic resin layer (A) side of the coextruded multilayer film (X2) obtained in Example 2 25 μm] was laminated by dry lamination to obtain a laminate film (Y3). At this time, as a dry lamination adhesive, a two-component curable adhesive (polyester adhesive LX63F and a curing agent KP90) manufactured by Dainippon Ink & Chemicals, Inc. was used.

  Next, a 110 × 150 mm bag was prepared in the same manner as in Example 1 except that the obtained laminate film (Y3) was used, and then the actual package (P-3) containing 50 g of dried plums was similarly prepared. Created.

  The actual packaged product (P-3) was torn by hand from the notched bag end to the opposite end, and 10 of the actual packaged product (P-2) were not easily tearable (NG). As a result of investigating whether it was judged, none was judged as having no easy tearability (NG), and all of them had good easy tearability.

  Subsequently, the remaining heat-sealed part of the actual package (P-3) after tearing was manually opened to expose the pressure-sensitive adhesive resin layer (B). When this exposed part was observed, both of the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C) of the laminate film (Y3) were broken and the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin were used. The layers of the layer (B) were peeled off, and the pressure-sensitive adhesive resin layer (B) was exposed in a resealable state on the surface of the heat seal region.

  Furthermore, after the films were pressure-bonded again with a finger, the seal strength (reseal strength) when opened again and the seal strength after repeated opening and resealing 10 times (repeated reseal strength) were measured. Was 2.5 N / 15 mm, and repeated reseal strength (10 times) was as good as 2.0 N / 15 mm.

Comparative Example 1
Biaxially stretched polypropylene base material that does not have easy tearability on the thermoplastic resin layer (A) side of the coextruded multilayer film (X2) obtained in Example 2 [Pyrene P2161, manufactured by Toyobo Co., Ltd., thickness 25 μm] Were laminated by dry lamination to obtain a laminate film (Y4). At this time, as a dry lamination adhesive, a two-component curable adhesive (polyester adhesive LX63F and a curing agent KP90) manufactured by Dainippon Ink & Chemicals, Inc. was used.

  Next, a 110 × 150 mm bag was prepared in the same manner as in Example 1 except that the obtained laminate film (Y4) was used, and then the actual package (P-3) containing 50 g of dried plums was also added. Created.

  The actual packaged product (P-4) was torn by hand from the notched bag end to the opposite end, and 10 of the actual packaged product (P-2) were not easily tearable (NG). As a result of investigating whether it was judged, there were nine pieces judged to have no easy tearability (NG), and the tearability was inferior.

  Subsequently, the remaining heat-sealed part of the actual package (P-3) after tearing was manually opened to expose the pressure-sensitive adhesive resin layer (B). When this exposed part was observed, both of the pressure-sensitive adhesive resin layer (B) and the heat seal resin layer (C) of the laminate film (Y4) were broken, and the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin were used. The layers of the layer (B) were peeled off, and the pressure-sensitive adhesive resin layer (B) was exposed in a resealable state on the surface of the heat seal region.

Next, after pressure-bonding the films again with a finger, the seal strength when reopened (reseal strength) and the seal strength after repeated opening and resealing 10 times (repeated reseal strength) were measured. The reseal strength was 2.5 N / 15 mm, and the repeat reseal strength (10 times) was as good as 2.0 N / 15 mm.

Claims (8)

It has resealability in which a thermoplastic resin layer (A), a pressure-sensitive adhesive resin layer (B), and a heat seal resin layer (C) are laminated in the order of (A) / (B) / (C). On the thermoplastic resin layer (A) of the coextruded multilayer film (I), the base film (II) having easy tearability is set so that the flow direction and tear direction of the coextruded multilayer film (I) are parallel to each other. An easily tearable laminate film characterized by being laminated. Resin in which coextruded multilayer film (I) contains amorphous olefin resin (b1), rubber thermoplastic resin (b2) and tackifier (b3) as pressure-sensitive adhesive resin layer (B) The easily tearable laminate film according to claim 1, which is a film having a layer. When the coextruded multilayer film (I) is heat-sealed with the heat-seal resin layer (C) in contact with each other and then peeled off, the pressure-sensitive adhesive resin layer (B) and the heat-seal resin layer (C ) Is broken and the thermoplastic resin layer (A) and the pressure-sensitive adhesive resin layer (B) are separated from each other, so that the pressure-sensitive adhesive resin layer (B) can be resealed at the heat seal portion. The easily tearable laminate film according to claim 1, which is a resealable coextruded multilayer film (3) exposed at A resealable coextruded multilayer film (3) comprising an ethylene- (meth) acrylic acid copolymer and / or a metal neutralized product thereof, a thermoplastic resin layer, an amorphous olefin resin, and styrene A pressure-sensitive adhesive resin layer containing a hydrogenated rubber block copolymer containing a block and a diene block and a tackifier (b3), and a heat seal resin layer containing an olefin resin The easily tearable laminate film according to claim 3, which is a coextruded multilayer film having a thickness of 20 to 60 μm laminated in order. The easily tearable laminate film according to claim 4, wherein the tackifier (B3) is at least one resin selected from the group consisting of a rosin resin, a terpene resin and a petroleum resin. The easily tearable laminate film according to any one of claims 1 to 5, wherein the base film (II) is a stretched polypropylene film, a stretched polyester film or a stretched polyamide film. The heat-sealing resin layer (C) of the easily tearable laminate film according to any one of claims 1 to 6 is superposed so as to be in contact with each other and heat-sealed at the edge of the film, and an opening is formed by tearing. A bag comprising two rows of heat-sealed portions parallel to the tearing direction of the base film (II) in the portion to be. The bag according to claim 7, further comprising a tear notch at a bag end portion between two rows of heat seal portions parallel to the tear direction.