JP6369221B2 - Package - Google Patents

Description

  The present invention relates to a package having a multilayer film as a lid or bottom material, and more particularly to a re-sealable package that is suitably used for packaging foods, pharmaceuticals, and the like.

  Conventionally, various packages with resealing function have been used as packaging means for cosmetics and sanitary products that are repeatedly opened and resealed every time they are used, or for food and pharmaceuticals that cannot be consumed once. . This package can prevent oxidative deterioration of the contents remaining after opening, or deterioration due to moisture absorption, drying, etc. For example, a zipper type package in which a plastic zipper is laminated is known. However, although this package can be repeatedly opened and has excellent durability, a dedicated device for attaching an accessory such as a zipper to the package is necessary, and a processing step associated therewith is also necessary. There are problems such as increased manufacturing costs and reduced production efficiency.

  On the other hand, a multilayer film that can give a reseal function to the package itself without attaching an accessory such as a zipper has been developed. For example, Patent Documents 1 and 2 include a surface resin layer, an adhesive resin layer containing a hydrogenated styrene-diene rubber block copolymer and a tackifier, and a heat seal resin layer. A multilayer film that can be exposed in an adhesive state in which the adhesive resin layer can be resealed at the heat seal portion when the multilayer film used as a lid material is peeled from the bottom material of the package is disclosed. Yes.

  However, these multilayer films contain a large amount of hydrogenated rubber block copolymer as essential components in the adhesive resin layer and tackifying resins such as rosin resins, terpene resins, petroleum hydrocarbon resins as essential components. Contains. When this multilayer film is used for food packaging, the amount of extraction tends to increase in the elution test using n-heptane, which is a pseudo-solvent for oily food, for the tackifying resin. It is preferable not to mix the tackifier resin with the adhesive resin layer as much as possible.

  Further, in Patent Documents 2 and 3, a heat seal resin layer (corresponding to a weld layer in Patent Document 3) and this heat seal resin layer and a heat-sealable thermoplastic resin layer are heat sealed, and then peeled off. In this case, the heat seal resin layer breaks and the heat seal resin layer and the adhesive resin layer (corresponding to the intermediate adhesive layer in Patent Document 3) are separated, and the adhesive resin layer is resealed at the heat seal portion. A package using a multilayer film characterized by being exposed in a possible adhesive state as a container lid is disclosed.

  However, in these packages, since the adhesive resin layer and the heat seal resin layer are directly adjacent, additives such as lubricants and antiblocking agents added to the heat seal resin layer after opening are exposed over time. There is a concern that the reseal peel strength with the adhesive resin layer may decrease due to bleeding on the surface of the heat seal resin layer.

  Patent Document 4 discloses a heat-sealing packaging material in which an adhesive resin layer (adhesive layer) and a heat seal agent layer are formed in this order on at least one surface of a base material, and the adhesive resin layer and the above-mentioned A packaging material is disclosed in which the adhesive strength between the heat sealant layers is smaller than the heat seal strength between the heat sealant layer and the layer to be heat sealed.

  Specifically, as an example, on a biaxially stretched polypropylene surface of a laminate film (thickness 50 μm) made of polyester and biaxially stretched polypropylene, 10% by mass of styrene and 90% by mass of a diene hydrocarbon are formed. Heat seal in which an adhesive resin layer having a thickness of 25 μm is laminated by extrusion lamination using a random copolymer with a hydrogenated product of a random copolymer, and a solvent-soluble acrylic heat seal lacquer is further coated on the adhesive resin layer The packaging material which laminated | stacked the agent layer is illustrated. In the case of a package body cut out in a circle with a tab and heat-sealed in a polystyrene container as a lid material, if the tab is pinched and pulled, peeling occurs at the interface between the adhesive resin layer and the heat-sealant layer, and the peeling occurs It is described that when a lid is placed on a container and pressure-bonded with a finger or the like, the adhesive resin layer re-adheres to the flange portion and is sealed again.

  However, the packaging body having the above structure has a process in which the adhesive resin is exposed to the outside before coating the heat sealing agent, and dust, dust, etc. floating in the atmosphere adhere to the adhesive resin. In some cases, resealability may be reduced, and special equipment such as a coater for coating and a drying equipment is required, resulting in an increase in manufacturing cost.

  The present inventors use the styrenic thermoplastic elastomer having specific viscoelastic properties as the main component of the adhesive resin layer, and arrange the release resin layer between the adhesive resin layer and the heat seal resin layer to achieve the above problem. Was found to be able to be solved, and succeeded in commercialization (Patent Documents 5 to 9).

  In Patent Documents 5 to 9, the heat seal resin layer (D) has olefin resin (ethylene resin, polypropylene resin, etc.), styrene resin, ester resin, and styrene thermoplastic resin elastomer as main components. It is disclosed that a resin is suitably used.

  In Patent Documents 6, 7, and 8, the heat seal resin layer (D) has a delamination strength between the release resin layer (C) and the adhesive resin layer (B) and the release resin layer (C). It is disclosed that an adhesive resin can be contained in the heat seal resin layer (D) in order to make it greater than the interlaminar peel strength.

  However, when an adhesive resin is disposed on the heat seal layer (D), the slipping property of the heat seal layer is reduced, and film roll defects such as winding slip, bumps, and width fluctuations occur, resulting in poor productivity. was there. In particular, when the roll is stored in a high temperature environment in summer, blocking occurs due to the low molecular weight component (sticky component) contained in the adhesive resin and the base material of the adhesive resin, and the heat seal surface becomes rough when unwinding the film There was a problem that transparency was lost. Moreover, it is necessary to spray blocking prevention powder on a surface resin layer (A) at the process of laminating | stacking laminate base materials, such as a lamination lamination and an extrusion lamination.

  Among conventional lid materials, a lid material using a polypropylene resin as a sealant has a high sealing temperature and is inferior in contaminant sealability. On the other hand, when a hot-melt type resin with improved low-temperature sealability is used in the heat seal layer of the lid, there is a problem that the hot tack property is poor, and if stress is applied immediately after sealing, delamination occurs.

JP 2003-175567 A JP 2004-75181 A Special Table 2000-500722 JP 2005-41539 A Japanese Patent No. 4749119 Japanese Patent No. 4902237 Japanese Patent No. 5106795 Japanese Patent No. 51212244 Japanese Patent No. 5117225

  The present invention has been made in order to solve the problems of the conventional multilayer film, and the problem to be solved is that the heat seal resin of the bottom or lid of the package body to be sealed is a propylene resin. Excellent blocking resistance, good low-temperature sealability (contaminant sealability and hot tack), excellent food hygiene, good easy-openability, and good pressure and pressure bonding with hands and fingers Another object of the present invention is to provide a re-sealable package that has both good resealability.

  As a result of intensive studies, the present inventors have used a styrene-based thermoplastic elastomer having specific viscoelastic properties as a main component of the adhesive resin layer, and a release resin layer between the adhesive resin layer and the heat seal resin layer. And using the random polypropylene adhesive resin having a specific Vicat softening point and molecular weight distribution for the heat seal resin layer, the inventors found that the above problems can be solved, and have completed the present invention.

  That is, the gist of the present invention is to cover a multilayer film in which a surface resin layer (A), an adhesive resin layer (B), a release resin layer (C), and a heat seal resin layer (D) are sequentially laminated. It is a package formed by heat-sealing the heat-seal resin layer (D) of the multilayer film on the bottom or lid of the package, which is a sealed body, In the sealing part, when the adhesive resin layer (B) and the release resin layer (C) are delaminated, both the layers are exposed in a resealable state, and the adhesive resin layer (B) Is a layer composed mainly of a styrene-based thermoplastic elastomer having a temperature showing a peak value of loss tangent (tan δ) measured at a frequency of 10 Hz by dynamic viscoelasticity measurement of −35 ° C. or more, and the heat Seal resin layer (D) The Vicat softening point is 80 ° C. or more and 105 ° C. or less, the peak value of the weight average molecular weight measured by the high temperature GPC method is 400,000 or more and 500,000 or less, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). The present invention lies in a package comprising a layer composed mainly of a random polypropylene adhesive resin having a polydispersity (Mw / Mn) of 1.5 or more and 2.3 or less.

  According to the present invention, it is excellent in blocking resistance, excellent in sealing properties of foreign substances with propylene resin and hot tack, good easy opening, and good resealability only by pressure pressing with hands and fingers. A re-sealable packaging body can be provided, and the industrial value of the present invention is high.

Partial sectional view of the package of the present invention using the multilayer film defined in the present invention as a lid In the package shown in FIG. 1, a partial cross-sectional view of the package in a state in which a part of the lid is peeled from the container In the package shown in FIG. 1, a partial cross-sectional view showing a state in which the lid and the bottom material are resealed Partial sectional view of the package of the present invention using the multilayer film defined in the present invention as a bottom material In the package shown in FIG. 4, a partial cross-sectional view of the package in a state where a part of the lid is peeled from the container 4 is a partial cross-sectional view showing a state where the lid and the bottom material are resealed in the package shown in FIG.

Hereinafter, the multilayer film with a reseal function, a lid material, a bottom material, and a package that constitute the package of the present invention will be described in detail.
In the present specification, “configured as a main component” is intended to allow other components to be included within a range that does not impede the action and effect of the resin constituting each layer. Further, this term does not limit the specific content, but it is 70% by mass or more and 100% by mass or less, preferably 85% by mass or more and 100% by mass or less, more preferably 95% by mass of the total components of each layer. It means that it occupies% or more and 100 mass% or less.

  The film constituting the package of the present invention is a multilayer film in which a surface resin layer (A), an adhesive resin layer (B), a release resin layer (C), and a heat seal resin layer (D) are sequentially laminated. The adhesive resin layer (B) is composed mainly of a styrene-based thermoplastic elastomer having a temperature at which a peak value of loss tangent (tan δ) measured at a frequency of 10 Hz by dynamic viscoelasticity measurement is −35 ° C. or more. The heat sealing resin layer (D) has a Vicat softening point of 80 ° C. or more and 105 ° C. or less, a peak value of weight average molecular weight measured by the high temperature GPC method is 400,000 or more and 500,000 or less, and weight The main component is a random polypropylene adhesive resin having a polydispersity (Mw / Mn) of 1.5 or more and 2.3 or less, which is the ratio of the average molecular weight (Mw) to the number average molecular weight (Mn). It is a multilayer film which consists of a layer comprised.

  And this multilayer film has the following function. That is, the multilayer film is used as one of the lid or bottom material of the packaging body, and the heat seal resin layer (D) of the multilayer film is heat sealed at the bottom material of the packaging body that is the sealed body or the heat seal portion of the lid material. Then, when the multilayer film is peeled from the heat seal portion, the adhesive resin layer (B) and the release resin layer (C) are delaminated in the heat seal portion, and the adhesive resin layer ( B) has a reseal function that is exposed to the release resin layer (C) in a resealable state.

  First, the surface resin layer (A) of the film will be described. The surface resin layer (A) is a layer composed of the thermoplastic resin (a) as a main component, and the delamination strength between the surface resin layer (A) and the adhesive resin layer (B) at the time of peeling is adhesive. The layer structure is not particularly limited as long as it is greater than the delamination strength between the resin layer (B) and the release resin layer (C), and may be a single layer or a multilayer.

  The thermoplastic resin (a) used as the main component of the surface resin layer (A) is the resin used as the main component of the adhesive resin layer (B), the release resin layer (C), and the heat seal resin layer (D). It is preferable to select appropriately considering the type. Since the thermoplastic resin (a) has a melt extrusion temperature in a range of approximately 180 ° C. or more and 300 ° C. or less, a thermoplastic resin that can be melt extruded within this range is suitably used. Specific examples of the thermoplastic resin (a) include olefin resins (ethylene resins, propylene resins, cyclic olefin resins, etc.), amide resins, saponified ethylene-vinyl acetate copolymers, ester resins, Examples thereof include styrene resins and carbonate resins. These thermoplastic resins can be used alone or as a mixed resin composition of two or more, and can form a single layer structure or a multilayer structure.

  In the present invention, in consideration of molding processability, production cost, transparency, etc., the thermoplastic resin (a) includes olefin resin, amide resin, saponified ethylene-vinyl acetate copolymer, ester resin, and At least one thermoplastic resin selected from the group consisting of styrenic resins can be suitably used.

  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 copolymer (EMA), ethylene-acrylic acid copolymer Polymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-glycidyl methacrylate copolymer (E-GMA), ethylene-vinyl acetate-glycidyl methacrylate copolymer (E-VA-GMA), ethylene- Maleic anhydride copolymer (E-MA ), Ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), and the like; and further, metal-neutralized ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer Examples thereof include a metal neutralized product of coalescence. These may be used alone or in combination of two or more.

  Examples of the propylene-based resin include propylene homopolymers, copolymers of propylene and other α-olefins such as ethylene and butene, and the copolymers include any of random copolymers and block copolymers. Can also be used. The stereoregularity may be any of an isotactic structure, a syndiotactic structure, an atactic structure, a stereo block structure, and the like. These may be used alone or in combination of two or more.

  Examples of the amide-based resin include, as aliphatic polyamide polymers, ring-opening polymers of cyclic lactams, polycondensates of aminocarboxylic acids, and polycondensates of dicarboxylic acids and diamines. Specifically, a homopolymer of ε-caprolactam referred to as 6 nylon, polyhexamethylene adipamide referred to as 66 nylon, or 6-66 nylon as a copolymer thereof can be used. Moreover, as an aromatic polyamide polymer, a resin containing 70 mol% or more of a polyamide constituent unit composed of xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms in the molecular chain, etc. Can be used. Specifically, homopolymers such as polymetaxylylene adipamide, polymetaxylylene pimeramide, polymetaxylylene azelamide, polyparaxylylene azelamide, polyparaxylylene decanamide, metaxylylene / paraxylylene azamide Examples of the copolymer include a amide copolymer, a metaxylylene / paraxylylene pimeramide copolymer, a metaxylylene / paraxylylene azeramide copolymer, and a metaxylylene / paraxylylene sepacamide copolymer. These may be used alone or in combination of two or more.

  The saponified ethylene-vinyl acetate copolymer has an ethylene content of 29% or more, preferably 32% or more, 47 mol% or less, preferably 44 mol% or less, and a saponification degree of 90%. Above, preferably 95% or more is suitably used. By selecting a grade in which the ethylene content and the degree of saponification are in the above ranges, the gas barrier properties and mechanical strength of the film can be improved. These may be used alone or in combination of two or more.

  Examples of the ester resin include polyethylene terephthalate resin, polypropylene terephthalate resin, polybutylene terephthalate resin, polyethylene isophthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, polyethylene terephthalate / isophthalate copolymer resin, 1,4-cyclohexane. Represented by low crystalline or amorphous polyethylene terephthalate resin, polyethylene / neopentyl terephthalate copolymer resin, and polylactic acid-based resin containing 15 to 50 mol% of dimethanol units in all glycol monomer units. Examples include aliphatic polyester resins.

  In addition, a thermoplastic polyester elastomer having a high melting point and high crystallinity aromatic polyester as a hard segment and an amorphous polyester or amorphous polyether as a soft segment may be appropriately mixed with the ester resin. These elastomers may be used alone or in a suitable mixture of two or more.

  Examples of the styrenic resin include general-purpose polystyrene (GPPS), high impact polystyrene (HIPS), styrene- (meth) acrylic acid ester copolymer, and a styrenic copolymer composed of a styrenic monomer and a (meth) acrylic acid ester. A resin containing 1% by mass or more and 20% by mass or less of a rubber-like elastic body as dispersed particles in the continuous phase. You may use these individually by 1 type or in mixture of 2 or more types.

  In order to impart functions such as gas barrier properties and pinhole resistance to the multilayer film, the surface resin layer (A) is composed of two or more layers, and the saponified ethylene-vinyl acetate copolymer is the main component. It is preferable to have at least one layer mainly composed of an amide resin or the like. However, when the surface resin layer (A) has a multilayer structure, the delamination strength between the resin layers constituting the multilayer is the delamination strength between the adhesive resin layer (B) and the release resin layer (C). It is also important to appropriately select and use an adhesive resin that is larger than that.

  Here, as the adhesive resin, ethylene-based resins such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), and ethylene-vinyl acetate copolymer (EVA), propylene homopolymer, and Propylene-based resins such as copolymers of propylene and other α-olefins, monobasic unsaturated fatty acids such as acrylic acid or methacrylic acid, or methyl acrylate, methyl methacrylate, or glycidyl methacrylate An olefin-based adhesive resin in which an ester compound of a monobasic unsaturated fatty acid or an anhydride of a dibasic fatty acid such as maleic acid, fumaric acid or itaconic acid is chemically bonded is preferably used. Specific examples of such an adhesive resin include trade name “Admer” manufactured by Mitsui Chemicals, Inc. and trade name “Modic” manufactured by Mitsubishi Chemical Corporation.

  Other components may be appropriately added to the surface resin layer (A) as long as the gist of the present invention is not impaired. Specific examples include components such as an antifogging agent, an antistatic agent, a heat stabilizer, a nucleating agent, an antioxidant, a lubricant, an antiblocking agent, a release agent, and an ultraviolet absorber. When the surface resin layer (A) has a multilayer structure, it may be added only to a specific layer or may be added to all layers.

  Next, the adhesive resin layer (B) will be described. The adhesive resin layer (B) is mainly composed of a styrene-based thermoplastic elastomer (b) having a temperature showing a peak value of loss tangent (tan δ) measured at a frequency of 10 Hz by dynamic viscoelasticity measurement of −35 ° C. or more. It is important that the layer is composed. Here, if the temperature showing the peak value of the loss tangent (tan δ) is −35 ° C. or higher, the pressure-sensitive adhesive layer (B) and the release resin layer (C) exposed at the time of peeling are only pressure-bonded by hand or fingers. It is preferable because of practical resealability. The resealability is presumed to be affected by viscoelastic properties at room temperature, particularly the value of loss tangent (tan δ), and the value of loss tangent (tan δ) at room temperature is 0.1 or more (upper limit) The value is usually more preferably about 0.6). Moreover, the upper limit of the temperature which shows the peak value of loss tangent (tan-delta) of a styrene-type thermoplastic elastomer (b) is 10 degrees C or less normally from the characteristic as an elastomer. Furthermore, since the package of the present invention may be used even in a low-temperature environment such as a refrigeration facility typified by a refrigerator, taking these into consideration, the temperature showing the peak value of loss tangent (tan δ) The preferred range is −35 ° C. or higher, more preferably −25 ° C. or higher, and 5 ° C. or lower, more preferably 0 ° C. or lower.

  The styrenic thermoplastic elastomer (b) is preferably styrene, a copolymer of a styrene homologue such as α-methylstyrene and a conjugated diene, or a hydrogenated derivative thereof. Here, examples of the conjugated diene constituting the conjugated diene moiety include 1,3-butadiene, isoprene, 1,3-pentadiene, and the like. These may be used singly or in combination of two or more in the copolymer. It may be included. However, the thermal stability and weather resistance when a double bond mainly consisting of vinyl bonds in the conjugated diene moiety remains are extremely poor. To improve this, 80% or more, preferably 95% of the double bonds. It is preferable to use one added with hydrogen.

  The temperature showing the peak value of the loss tangent (tan δ) of the styrenic thermoplastic elastomer (b) mainly consists of the styrene content and the vinyl bond content of the conjugated diene part (for example, 1,2 bond in the case of butadiene, isoprene). In this case, the amount depends on the amount of 1,2 and 3,4 bonds. In the present invention, the styrene content is 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, 25% by mass or less, preferably 20% by mass or less, more preferably 15% by mass or less. A styrenic thermoplastic elastomer having a vinyl bond content of the conjugated diene moiety of 40 mol% or more, preferably 50 mol% or more is suitably used.

  Specific examples of such a styrenic thermoplastic elastomer include the product name “Hibler 7311” manufactured by Kuraray Co., Ltd., the product name “Tuftec H1221” manufactured by Asahi Kasei Co., Ltd., and the product name “Dynalon” manufactured by JSR Corporation. 1320P "etc. can be illustrated.

  Other resins and components may be appropriately added to the pressure-sensitive adhesive resin layer (B) as long as the gist of the present invention is not impaired. Specific examples include low crystalline or amorphous olefin resins, softeners, oils (mineral oils), stabilizers (antioxidants, etc.), liquid paraffin, and the like.

  Next, the release resin layer (C) will be described. The release resin layer (C) is a layer composed mainly of the thermoplastic resin (c), and the delamination strength between the adhesive resin layer (B) and the release resin layer (C) during the peeling is the surface. Especially if it is a layer structure which becomes smaller than the delamination strength between the resin layer (A) and the adhesive resin layer (B) and between the release resin layer (C) and the heat seal resin layer (D) However, it may be a single layer or multiple layers as desired.

  The thermoplastic resin (c) contained as the main component of the release resin layer (C) has a melt extrusion temperature of about 180 ° C. or higher, like the thermoplastic resin (a) constituting the main component of the surface resin layer (A). A thermoplastic resin that can be melt-extruded at 300 ° C. or lower is preferably used. Specifically, as the thermoplastic resin (c), the balance between easy-openability and resealability with the adhesive resin layer (B) containing the styrenic thermoplastic elastomer (b) as a main component, molding processability and transparency. In view of the properties, at least one thermoplastic resin selected from the group consisting of ester resins, amide resins, cyclic olefin resins, and saponified ethylene-vinyl acetate copolymers may be mentioned.

  In the present invention, the thermoplastic resin (c) that is suitably used in the release resin layer (C) is excellent in rigidity, and the adhesive resin layer (B) by an external force at the time of delamination from the adhesive resin layer (B). And the release surface of the release resin layer (C) can be reduced in roughness, unevenness of each layer, etc., easy openability and good resealability when opening-resealing is repeated, industrially stable, It is also preferable to use an amide resin that is available at a relatively low cost. Among them, it is excellent in moldability, transparency, etc., and does not delaminate or open with a slight impact, and can be easily delaminated when opening, 6-66 nylon, 12 nylon, terephthalic acid, etc. An amide resin such as a low crystalline or amorphous polyamide resin obtained by reacting a dicarboxylic acid such as isophthalic acid with a diamine such as hexamethylenediamine or isophoronediamine can be preferably used.

  Examples of the amide-based resin include 6-66 nylon resin such as “Novamid 2063” manufactured by Mitsubishi Engineering Plastics Co., Ltd. and “UBE Nylon 5033B” manufactured by Ube Industries, Ltd. Examples of the 12 nylon resin include a product name “UBESTA 3035UF” manufactured by Ube Industries, Ltd., a product name “Griramid L25” manufactured by EMS Showa Denko Corporation, and the like. Examples of the amorphous polyamide resin include trade name “Novamid X21” manufactured by DSM Japan Engineering Plastics Co., Ltd. and trade name “Sealer PA3426” manufactured by Mitsui DuPont Polychemical Co., Ltd.

  By disposing the release resin layer (C) between the adhesive resin layer (B) and the heat seal resin layer (D), the heat seal portion of the bottom material or lid material of the package body to be sealed is configured. Without being limited to the resin, it is possible to impart a good initial peel strength and resealability with the adhesive resin layer (B). In the present invention, it is preferable to use, as the thermoplastic resin (c), a thermoplastic resin having an excellent initial peel strength from the adhesive resin layer (B) and resealability rather than the thermoplastic resin (d).

  Specifically, as the resin constituting the heat seal portion of the sealed object, an olefin resin that can be heat-sealed under the heat seal condition (temperature: about 120 to 180 ° C.) that is usually employed is mainly used. However, in the present invention, considering the low-temperature sealing property (hot tack property immediately after sealing and foreign matter sealing property), good initial peel strength and resealability with the adhesive resin layer (B) are obtained. As the release resin layer (C), the amide resin is used, and as the heat seal resin layer (D), the Vicat softening point is 80 ° C. or more and 105 ° C. or less, and the peak value of the weight average molecular weight measured by the high temperature GPC method is 400,000 or more. Randomness of 500,000 or less and polydispersity (Mw / Mn), which is a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn), of 1.5 or more and 2.3 or less The polypropylene based adhesive resin respectively selecting the layer mainly composed.

  In addition, in the release resin layer (C), in order to develop stable resealability between the adhesive resin layer (B) and the release resin layer (C), mixing with an additive that easily bleeds on the surface of the release resin layer (C) It is preferable not to do as much as possible.

  Next, the heat seal resin layer (D) will be described. The heat seal resin layer (D) has a Vicat softening point of 80 ° C. or more and 105 ° C. or less, a peak value of weight average molecular weight measured by the high temperature GPC method is 400,000 or more and 500,000 or less, and a weight average molecular weight (Mw). Heat-sealable resin layer comprising, as a main component, a random polypropylene-based adhesive resin (d) having a polydispersity (Mw / Mn) which is a ratio of the number average molecular weight (Mn) of 1.5 to 2.3. It is.

When the heat seal resin layer (D) is heat-sealed at the heat-sealed portion of the object to be sealed and then the multilayer film is peeled off from the heat-sealed portion, the release resin layer (C) and the heat seal resin layer (D ) Between the adhesive resin layer (B) and the release resin layer (C) is not particularly limited as long as it has a layer structure. It may be a resin layer having a layer structure or a resin layer having a multilayer structure.

  Random polypropylene adhesive resin (d) is made of the sealing material of the lid or bottom material, the surface resin layer (A), the adhesive resin layer (B), and the release resin layer (C), which are the objects to be sealed. In consideration of the type of resin used as the main component, a resin having an appropriate heat seal strength can be appropriately selected and used.

  The random polypropylene adhesive resin (d) is produced using a known Ziegler catalyst, vanadium catalyst, single site catalyst, etc., and a metallocene catalyst, a geometrically constrained catalyst (CGC), or a nonmetallocene complex is used as the single site catalyst. A catalyst etc. are mentioned.

Among them, the random polypropylene adhesive resin manufactured using a single site catalyst shows a very sharp molecular weight distribution compared to the random polypropylene adhesive resin manufactured using a conventional Ziegler-Natta catalyst, Since the distribution is uniform, blocking is difficult and surface lubricity is excellent.
Therefore, it is not necessary to use an anti-blocking powder, and even when a slip agent or an anti-blocking agent is added, the amount added can be reduced. Further, even during high-temperature storage, blocking can be prevented because there is little elution of low molecular weight components. Furthermore, the sealing temperature can be lowered even for a bottom material using a polypropylene resin as a sealant, and the contaminant sealing property and hot tack property are excellent.

  On the other hand, when a random polypropylene-based adhesive resin using a Ziegler-Natta catalyst is used, since a low molecular weight component is contained, it is easy to block and a defective phenomenon occurs, resulting in poor productivity. Further, in storage at high temperatures, there is a problem that the sticking component such as a low molecular weight component causes blocking, and the heat seal tree surface becomes rough when unwinding.

  Examples of the random polypropylene adhesive resin (d) suitable for the present invention include propylene homopolymers, and propylene resins such as propylene and α-olefin copolymers via a single site catalyst, acrylic acid, or Monobasic unsaturated fatty acids such as methacrylic acid, or ester compounds of monobasic unsaturated fatty acids such as methyl acrylate, methyl methacrylate, or glycidyl methacrylate, or dibasic such as maleic acid, fumaric acid or itaconic acid Polypropylene in which a fatty acid anhydride or the like is chemically bonded is preferably used. These may be used alone or in combination of two or more.

Among these, the random polypropylene adhesive resin having a Vicat softening point of 80 ° C. or higher and 105 ° C. or lower is used in film slitting work (mechanically making a cut in the film winding direction and winding it while cutting). It is possible to finish with a good roll appearance without causing defects such as wrinkles, shifts and sagging.
The lower limit of the Vicat softening point is preferably 85 ° C. or higher, and the upper limit is preferably 100 ° C. or lower.

  When the Vicat softening point is 80 ° C. or lower, the softening point tends to block at high temperatures, so that the Vicat softening point tends to block. Further, when the Vicat softening point is 105 ° C. or higher, the sealing temperature must be increased, the contaminant sealing property is inferior, the hot tack property is poor, and if stress is applied immediately after sealing, delamination occurs. The problem becomes noticeable.

  In the present invention, the “Vicat softening point” refers to the Vicat softening point measured by a method defined in JIS K7206 (1999) [Plastic-thermoplastic plastic—Vicat softening temperature (VST) test method].

  The peak value of the weight average molecular weight of the heat seal resin layer (D) of the present invention is preferably from 400,000 to 500,000, and more preferably from 410000 to 490000. The higher the molecular weight of the peak value and the sharper, the smaller the branching of the side chain, and the more uniform the molecular weight and comonomer distribution.

  In the conventional Ziegler-Natta catalyst, since the peak value of the weight average molecular weight is less than 400,000 and the molecular weight distribution tends to be wide, the amount of low molecular weight components increases, causing stickiness. On the other hand, if the peak value of the weight average molecular weight is 500,000 or more, the extrusion moldability is deteriorated and film formation becomes difficult. In the present invention, the molecular weight peak value means the maximum molecular weight measured by high-temperature GPC.

  The weight average molecular weight (Mw) / number average molecular weight (Mn) ratio (hereinafter referred to as polydispersity Mw / Mn) representing the molecular weight distribution is preferably 1.5 to 2.3. More preferably, it is from 8 to 2.3. This means that the smaller the Mw / Mn, the smaller the variation in the molecular weight of the comonomer and the narrower the molecular weight distribution. However, when the Mw / Mn is less than 1.5, problems such as a decrease in extrusion moldability occur. Production is difficult. On the other hand, when Mw / Mn exceeds 2.3, the amount of low molecular weight components increases, and problems such as easy film blocking due to elution of the low molecular weight components occur.

  Specific examples of such adhesive resins include metallocene catalyzed random polypropylene adhesive resins such as Mitsui Chemicals' brand name “Admer” and Mitsubishi Chemical Corporation's brand name “Modic”. It can be illustrated.

  Further, the heat-seal resin layers (D) are overlapped, stored in a constant temperature layer at 40 ° C. for 24 hours, left to stand at 23 ° C. and 50% RH for 24 hours, and then the blocking force measured by ASTM 3354 is 3N or less. And more preferably 2.5N or less. If the blocking force is 3N or more, defects such as wrinkles, displacement and sagging may occur during slit processing.

  It is preferable to add a lubricant or an anti-blocking agent to the heat seal resin layer (D) as appropriate from the viewpoints of processing suitability during extrusion film formation and packaging suitability in a filling machine such as a deep drawing packaging machine. Here, when the surface resin layer (A) / adhesive resin layer (B) / heat seal resin layer (D) disclosed in Patent Document 1 are laminated in this order and the heat seal portion is peeled off, the adhesive resin layer In the multilayer film which peels between the layers of (B) and the heat seal resin layer (D), there are the following problems.

  That is, since the adhesive resin layer (B) and the heat seal resin layer (D) are directly adjacent to each other, additives such as a lubricant and an antiblocking agent added to the heat seal resin layer (D) after opening are changed over time. There is a concern that the reseal peel strength with the adhesive resin layer (B) may decrease due to bleeding on the exposed surface of the heat seal resin layer. On the other hand, like the multilayer film prescribed | regulated by this invention, the peeling resin layer (C) was distribute | arranged between the adhesion resin layer (B) and the heat seal resin layer (D), and the heat seal part was peeled off. In the case of a multilayer film that delaminates between the adhesive resin layer (B) and the release resin layer (C), additives such as lubricants and antiblocking agents that are suitably added to the heat seal resin layer (D) Since it is difficult to directly affect the peeled portion, there is also an advantage that stable resealability can be obtained with little influence on reseal strength.

  Furthermore, you may add suitably another component to the heat seal resin layer (D) in the range which does not impair the main point of this invention. Specific examples include antifogging agents, antistatic agents, heat stabilizers, nucleating agents, antioxidants, mold release agents, and ultraviolet absorbers.

  When the multilayer film specified in the present invention heat-seal the resin layer (D) of the film at the heat-sealed portion of the object to be sealed and then peel the multilayer film from the heat-sealed portion, the adhesive resin layer (B ) In the heat seal portion, the release resin layer (C) and the heat seal resin layer (D) are broken from the multilayer film, and the adhesive resin layer (B) and the release resin layer (C). ), And the release resin layer (C) and the heat seal resin layer (D) are transferred to the sealed body side. The delamination strength between the resin layer (B) and the release resin layer (C) is between the surface resin layer (A) and the adhesive resin layer (B), and between the release resin layer (C) and the heat seal resin layer (D Between) It is preferable to reduce consisting configuration than away strength. At the same time, it is also important to ensure the delamination strength to such an extent that the function as a package can be maintained so that the layers are not easily peeled off or opened by a slight impact.

  From these viewpoints, as a combination of resins selected for the adhesive resin layer (B) and the release resin layer (C), the interlayer peel strength (initial peel strength) is in the range of 1 N / 15 mm width to 20 N / 15 mm width. It is preferable to select as follows. Here, if the delamination strength is 1 N / 15 mm width or more, problems such as easy opening of the packaging body due to a slight impact are unlikely to occur, and if it is 20 N / 15 mm width or less, the packaging body Is easy because it is easy to open by hand, which is preferable.

  In the present invention, the more preferable range of the interlaminar peel strength (initial peel strength) between the adhesive resin layer (B) and the release resin layer (C) has a lower limit of 3 N / 15 mm width or more, and more preferably 5 N / 15 mm. It is not less than the width and the upper limit is not more than 15 N / 15 mm width, more preferably not more than 10 N / 15 mm width.

  Next, with regard to resealability after opening, for example, the adhesive resin layer (B) and the release resin layer (C) after repeated opening and resealing a total of 5 times only by pressure pressing with hands or fingers. The delamination strength (reseal peel strength) is preferably 0.5 N / 15 mm width or more. Here, the reseal peel strength is 0.5 N / 15 mm width or more, preferably 0.75 N / 15 mm width or more, more preferably 1.0 N / 15 mm width or more (only re-seal strength is obtained by pressure bonding with hands or fingers). The upper limit of the sealing peel strength is not more than the delamination strength between the adhesive resin layer (B) and the release resin layer (C), preferably not more than 10 N / 15 mm width, more preferably not more than 5.0 N / 15 mm width. If so, it is preferable because practical resealability can be obtained.

  In the present invention, as a preferable combination of the surface resin layer (A), the adhesive resin layer (B), the release resin layer (C), and the heat seal resin layer (D) satisfying such a condition, as described above, the surface The resin layer (A) is mainly composed of at least one thermoplastic resin selected from the group consisting of an olefin resin, an amide resin, a saponified ethylene-vinyl acetate copolymer, an ester resin, and a styrene resin. A styrene-based thermoplastic elastomer having a temperature of −35 ° C. or higher, which is a layer having a structure and has a peak value of loss tangent (tan δ) measured at a frequency of 10 Hz by dynamic viscoelasticity measurement as an adhesive resin layer (B) A layer composed mainly of an ester-based resin as the release resin layer (C), and a heat seal resin layer As D), the peak value of the weight average molecular weight measured by the high temperature GPC method at a Vicat softening point of 80 ° C. or more and 105 ° C. or less is 400,000 or more and 500,000 or less and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) Examples thereof include a layer composed mainly of a random polypropylene adhesive resin having a dispersity (Mw / Mn) of 1.5 or more and 2.3 or less.

  Next, the thickness of each layer described above will be described. The surface resin layer (A) is a resin layer having a single layer or a multilayer structure, and usually has a thickness of 1 μm or more, preferably 10 μm or more, more preferably 20 μm or more, and 1000 μm or less, preferably 600 μm or less, Preferably it is 500 micrometers or less. Here, if the thickness of the surface resin layer (A) is 1 μm or more, it is easy to dispose a layer imparting characteristics such as gas barrier properties and pinhole resistance and an adhesive resin layer, and the thickness thereof. Is preferably 1000 μm or less, because heat can be easily transferred to the heat seal resin layer (D) during heat sealing, and can be easily heat sealed with the sealing portion of the object to be sealed.

  The adhesive resin layer (B) is usually a resin layer having a single layer structure, and the thickness thereof is not particularly limited, but the balance between easy-openability and resealability, moldability, production cost, etc. Therefore, 0.5 μm or more, preferably 5 μm or more, more preferably 10 μm or more and 100 μm or less, preferably 70 μm or less, more preferably 50 μm or less is suitably employed.

  The total thickness of the release resin layer (C) and the heat seal resin layer (D) is not particularly limited, but is 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, 30 μm or less, preferably 25 μm. In the following, it is more preferable that the thickness is 15 μm or less. Here, if the total thickness is 1 μm or more, it is preferable because the deformation such as pressurization by a heat seal hot plate at the time of heat sealing can prevent problems such as deterioration of the function of each layer, and the thickness is also preferable. If it is 30 μm or less, the release resin layer (C) and the heat seal resin layer (D) can be easily broken when the adhesive resin layer (B) and the release resin layer (C) are peeled off. It is preferable because the layer (B) can be exposed in a resealable state.

  Further, the thickness of the release resin layer (C) is 0.5 μm or more, preferably 2 μm or more, more preferably 3 μm or more and 29.5 μm or less, preferably 20 μm or less, more preferably 10 μm or less. If the thickness of the release resin layer (C) is 0.5 μm or more, the release resin layer (C) is deformed by the heat sealing pressure during heat sealing, and there are few problems such as a decrease in the function as the release resin layer. If the thickness is 29.5 μm or less, the release resin layer (C) can be easily broken at the time of opening even when a resin having a high rigidity such as an ester resin is disposed. The layer (C) and the heat seal resin layer (D) are preferred because they do not easily break down such as a layer remaining on the multilayer film side without breaking.

  Further, the thickness of the heat seal resin layer (D) is 0.5 μm or more, preferably 2 μm or more, more preferably 3 μm or more and 29.5 μm or less, preferably 20 μm or less, more preferably 10 μm or less. When the thickness of the heat seal resin layer (D) is 0.5 μm or more, the release resin layer (C) and good interlayer adhesive strength can be maintained. Moreover, the release resin layer (D) is deformed by the heat seal pressure during heat sealing, which is preferable because defects such as deterioration of the function as the heat seal resin layer are reduced, and the thickness is preferably 29.5 μm or less. For example, even when a resin having a high impact strength such as a metallocene random polypropylene adhesive resin is disposed on the heat seal resin layer (D), it is easily broken at the time of opening, and the release resin layer (C) and the heat seal resin layer (D) is preferable because defects such as a layer remaining on the multilayer film side without being broken are less likely to occur.

  Next, the manufacturing method of the film of this invention is demonstrated. Although it does not restrict | limit especially as a manufacturing method of the film of this invention, The coextrusion method excellent in protection, productivity, hygiene, etc. of an adhesive resin layer (B) can be used suitably. That is, each resin composition used for the surface resin layer (A), the adhesive resin layer (B), the release resin layer (C), and the heat seal resin layer (D) described above is heated and melted in a separate extruder, After being laminated in the order of (A) / (B) / (C) / (D) in a molten state by a known method such as a multi-manifold method or a feed block method, a multilayer film is formed by a T-die / chill roll method or an inflation method. Can be molded. Here, in order to improve printing suitability and laminate suitability, it is preferable to perform a surface treatment on the surface of the outermost layer of the surface resin layer (A) of the obtained multilayer film. Examples of the surface treatment method include corona treatment, plasma treatment, chromic acid treatment, flame treatment, surface oxidation treatment such as hot air treatment ozone / ultraviolet treatment, sand blasting, and the like. Corona treatment is preferably used from the viewpoint of effects, productivity, and manufacturing cost.

  The multilayer film specified in the present invention is formed on the surface resin layer (A) opposite to the surface on which the adhesive resin layer (B) is laminated by a known method such as a dry lamination method or an extrusion lamination method, as necessary. Then, a laminate base material can be laminated through an adhesive resin, an adhesive, or the like to obtain a laminate film or laminate sheet. Here, the laminate substrate is not particularly limited, for example, biaxially stretched polypropylene film, biaxially stretched nylon film, biaxially stretched polyethylene terephthalate film, unstretched polypropylene sheet, unstretched polyethylene terephthalate sheet, An aluminum foil, paper, a nonwoven fabric, etc. are mentioned. In the present invention, a dry lamination method is preferably used, and examples of the adhesive used at that time include a polyester-polyurethane adhesive and a polyether-polyurethane adhesive.

  In the present invention, the film itself or a laminate film or laminate sheet obtained by laminating a film and a laminate base material can be used as a cover material or a bottom material of various packaging bodies, respectively. For example, when a laminate film is used as a lid for a package (container), the package (container) (sealed body) filled with a heat seal resin layer (D) of the lid and contents such as food By overlapping and heat-sealing with the heat-sealing resin layer, a package (container) having airtightness, practical initial peel strength, and resealing function can be obtained. This package (container) is exposed on the peeled surface after opening in a state where the adhesive resin layer (B) can be resealed, and can be resealed only by pressure pressing with a hand or a finger. Moreover, as a bottom material of various packaging bodies (containers), it is possible to obtain a packaging body (container) having a reseal function similarly by performing deep drawing or the like.

Next, the resealing function in the deep drawn package using the multilayer film defined in the present invention as a lid or bottom material will be described. FIG. 1 is a partial cross-sectional view of a deep-drawn package using a multilayer film defined in the present invention as a lid, and FIG. 2 is a diagram illustrating a part of the lid in the deep-drawn package shown in FIG. FIG. 3 is a partial cross-sectional view showing a state in which the lid material and the bottom material are resealed in the deep-drawn package shown in FIG. 2.
FIG. 4 is a partial cross-sectional view of a deep-drawn package using the film defined in the present invention as a bottom material, and FIG. 5 is a diagram illustrating a part of the lid material in the deep-drawn package shown in FIG. FIG. 6 is a partial cross-sectional view of the deep-drawn package body in a state of being peeled from the material, and is a partial cross-sectional view showing a state in which the lid material and the bottom material are resealed in the deep-drawn package body shown in FIG. 5.

  1 to 3, reference numeral 1 is a lid member, reference numeral 2 is a bottom material (sealed body), reference numeral 3 is a surface resin layer of the lid member, reference numeral 4 is an adhesive resin layer of the lid member, and reference numeral 5 is a lid member. , 6 is a heat seal resin layer of the lid material, 7 is a surface resin layer of the bottom material, 8 is a heat seal resin layer of the bottom material, 9 is a heat seal portion, 10 is a tab portion, Reference numeral 11 denotes an exposed portion of the adhesive resin layer 4 at the time of peeling, and reference numeral 12 denotes an exposed portion of the peeling resin layer 5 at the time of peeling.

  4 to 6, reference numeral 41 is a bottom material, reference numeral 42 is a lid member (sealed body), reference numeral 43 is a bottom surface resin layer, reference numeral 44 is a bottom adhesive resin layer, and reference numeral 45 is a bottom material. Peeling resin layer, reference numeral 46 is a heat seal resin layer of the bottom material, reference numeral 47 is a surface resin layer of the cover material, reference numeral 48 is a heat seal resin layer of the cover material, reference numeral 49 is a heat seal portion of the cover material, and reference numeral 50 is a cover. The tab part of the material, reference numeral 51 is an exposed part of the adhesive resin layer 44 at the time of peeling, and reference numeral 52 is an exposed part of the peeling resin layer 45 at the time of peeling.

  As shown in FIG. 1, in the package of the present invention, the cover material 1 includes a surface resin layer 3, an adhesive resin layer 4, a release resin layer 5, and a heat seal resin layer 6 in this order. The heat seal resin layer 6 of the lid 1 is heat-sealed with the heat seal resin layer 8 of the bottom material 2 that is the object to be sealed. That is, the lid member 1 and the bottom member 2 are bonded by the heat seal portion 9 formed by heat sealing.

  When the tab portion 10 provided on the lid member 1 is picked and pulled, as shown in FIG. 2, in the heat seal portion 9, first, the release resin layer 5 and the heat seal resin layer 6 on the tab portion 10 side are separated from the lid material 1. While being broken, peeling is started between the adhesive resin layer 4 and the release resin layer 5 in the lid member 1. When peeling between the adhesive resin layer 4 and the release resin layer 5 reaches the heat seal portion 9 on the side opposite to the tab portion 10 side, the release resin layer 5 and the heat seal resin layer 6 of the lid member 1 are broken. The release resin layer 5 and the heat seal resin layer 6 of the lid material 1 that has been broken move to the bottom material 2 side that is a sheet body, and the exposed portion 11 of the adhesive resin layer 4 and the exposed portion 12 of the release resin layer 5 It is formed.

  In the case of resealing, as shown in FIG. 3, the peeled cover material 1 is covered on the bottom material 2, and the surface resin layer 3 is pressure-bonded by hand or fingers to form the adhesive resin layer 4 of the cover material 1. By overlapping the exposed portion 11 and the exposed portion 12 of the release resin layer 5 of the lid material 1 that has moved to the bottom material 2, the lid material 1 and the bottom material 2 can be resealed.

  On the other hand, when the multilayer film defined in the present invention is used as a bottom material of a deep drawn package, as shown in FIG. 4, the bottom material 41 includes a surface resin layer 43, an adhesive resin layer 44, a release resin layer 45, and The heat seal resin layer 46 is laminated in this order. As in FIG. 1, the lid member 42 and the bottom member 41 are bonded together by a heat seal portion 49 formed by heat sealing.

  When the tab portion 50 provided on the lid member 42 is pinched and pulled, as shown in FIG. 5, first, in the heat seal portion 49, the release resin layer 45 and the heat seal resin layer 46 on the tab portion 50 side break from the bottom material 41. At the same time, peeling is started between the adhesive resin layer 44 and the release resin layer 45 in the bottom material 41. When the peeling between the adhesive resin layer 44 and the release resin layer 45 reaches the heat seal portion 49 on the side opposite to the tab portion 50 side, the release resin layer 45 and the heat seal resin layer 46 of the bottom material 41 are broken. The peeled resin layer 45 and the heat seal resin layer 46 of the broken bottom material 41 are transferred to the lid member 42 that is the sheet body, and the exposed portion 51 of the adhesive resin layer 44 and the exposed portion 52 of the surface resin layer 45 are separated. It is formed.

  Then, as shown in FIG. 6, when resealing, cover the peeled lid material 42 on the bottom material 41, and press and pressure-bond the surface resin layer 47 of the lid material with a hand or a finger to obtain the bottom material. The cover material 42 and the bottom material 41 can be resealed by overlapping the exposed portion 51 of the adhesive resin layer 44 of 41 and the exposed portion 52 of the release resin layer 45 of the bottom material 41 transferred to the cover material 42. .

  The package of the present invention can be used as a lid or bottom material for various containers, and its use is not particularly limited. For example, instant noodles, snack confectionery, chocolate confectionery, livestock meat processing such as sliced ham Such as cosmetics, sanitary products, shipping medicines, emergency adhesive plasters, throat candy, etc. that are used as containers packed in several units, such as products, wet tissues, sweat paper, fragrances, disposable diapers, etc. It can be used as a container in which pharmaceutical products are packaged. In particular, it can be suitably used as a package for storing contents that remain susceptible to deterioration such as oxidative deterioration, moisture absorption, and drying after the opening.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. In addition, the various measured value and evaluation about the film displayed in this specification were performed as follows. Here, the flow direction from the extruder of the film is called the vertical direction, and the orthogonal direction is called the horizontal direction.

(1) Temperature showing peak value of loss tangent (tan δ) A sample was cut into a length of 4 mm and a width of 60 mm, and a viscoelastic spectrometer DVA-200 (manufactured by IT Measurement Co., Ltd.) was used, with a vibration frequency of 10 Hz and a strain of 0.1. %, Temperature rising rate of 3 ° C./min, and chuck spacing of 25 mm, the lateral direction was measured from −100 ° C., and the temperature (° C.) showing the peak value of loss tangent (tan δ) was obtained from the obtained data.

(2) Vicat softening point A plate-shaped test piece of about 10 mm × width 10 mm × thickness 3 mm was molded by injection molding and then left in a constant temperature and humidity chamber at a temperature of 23 ° C. and a relative humidity of 50% for 24 hours to adjust the state. . Using a heat distortion tester S3EH type (Toyo Seiki Seisakusho), the temperature at which the indenter entered 1 mm into the test piece was measured under the condition of a heating rate of 50 ° C./hr using a 50 N weight. The test was performed twice, and the average value was defined as the Vicat softening point (° C.).

(3) Peak value of weight average molecular weight and polydispersity of molecular weight After dissolving 4 mg of a sample pellet in 4 ml of a solvent o-dichlorobenzene at 140 ° C., a column using a high temperature GPC system GPCV2000 (manufactured by Nippon Waters Co., Ltd.) Styragel HT6E, 4,3 (4.6 mm diameter 300 mm, triple) (manufactured by Nippon Waters Co., Ltd.), standard sample polystyrene, temperature 140 ° C., weight average molecular weight (Mw) and number average molecular weight (Mn) Analysis was conducted to determine the peak value of the weight average molecular weight and the molecular weight polydispersity (Mw / Mz).

(4) Initial peeling strength The bottom material of the obtained deep-drawn package and the heat seal part of the lid were cut into strips having a width of 15 mm and used as test pieces. This test piece was measured using a universal testing machine (manufactured by Intesco) under the conditions of a temperature of 23 ° C., a tensile speed of 200 mm / min, and a tensile angle of 180 degrees, and an adhesive resin layer (B) and a release resin layer (C) The initial peel strength was defined as the interlaminar peel strength (N / 15 mm width). In addition, the following standards are also shown.
A: When the initial peel strength is 5 N / 15 mm width or more and 10 N / 15 mm B: When the initial peel strength is less than 5 N / 15 mm width or 10 N / 15 mm or more

(5) Remaining layer The situation when peeled by hand from the bottom seal of the obtained deep-drawn package and the heat seal part of the lid was visually evaluated according to the following criteria.
A: When the release resin layer (C) and the heat seal resin layer (D) are cleanly broken from the multilayer film and do not fluff B: The release resin layer (C) and the heat seal resin layer (D) are the multilayer film If there is fuzz even if it cannot be broken from

(6) Reseal peel strength The bottom material of the obtained deep-drawn package and the heat seal part of the lid were cut into strips of 15 mm width and used as test pieces. The heat seal part is opened, and the part peeled between the adhesive resin layer (B) and the release resin layer (C) is pressure-pressed with a finger and resealed five times. Then, using a universal testing machine (manufactured by Intesco), the peel strength (N / 15 mm width) measured under the conditions of a temperature of 23 ° C., a tensile speed of 200 mm / min, and a tensile angle of 180 degrees was defined as the re-sealing peel strength. In addition, the following standards are also shown.
A: When the reseal peel strength is 0.5 N / 15 mm width or more B: When the reseal peel strength is less than 0.5 N / 15 mm width

(7) Sliding property The static friction coefficient of the surface resin layer (A) and the heat seal resin layer (D) of the obtained multilayer film was measured by the method defined in JIS K 7125. In addition, the following standards are also shown.
A: When the static friction coefficient is less than 2.0 and the roll appearance is good when slitting B: When the static friction coefficient is 2.0 or more and the roll appearance is poor when slitting

(8) Blocking property The obtained multilayer film was cut into a size of 10 × 15 cm, the heat seal resin layers (D) were overlapped, and sandwiched between glass plates. It was stored in a constant temperature layer at 40 ° C. for 24 hours and then left at 23 ° C. and 50% humidity for 24 hours. Two films were peeled off by a tensile tester by the method of ASTM D3354, and the blocking force was measured. In addition, the following standards are also shown.
A: Blocking force is 3N or less B: Blocking force is 3N or more

(9) Interlaminar adhesive strength The obtained multilayer film was cut into a strip shape having a width of 15 mm and used as a test piece. The heat seal layers (D) of the test pieces are stacked and heat sealed, and the release resin layer (C) and the heat seal resin layer (D) are peeled off, and a universal testing machine (manufactured by Intesco Co., Ltd.) is attached. The peel strength (N / 15 mm width) measured under the conditions of a temperature of 23 ° C., a tensile speed of 200 mm / min, and a tensile angle of 180 degrees was defined as an interlayer adhesive strength. In addition, the following standards are also shown.
A: When the interlayer adhesion strength is 1.5 N / 15 mm width or more B: When the interlayer adhesion strength is less than 1.5 N / 15 mm width

(10) Sealing start temperature In the heat sealing between the lid and the bottom material, a deep drawing packaging machine (manufactured by Mulchback, model number R-530, sealing time 2 seconds, sealing pressure 4 kg / cm ² ) is used. It carried out on the conditions set at 10 degreeC or more above 130 degreeC, and it was confirmed by pulling both materials by hand whether the seal was made.
The lowest sealing temperature at which sealing could be performed reliably was taken as the sealing start temperature.
The lower the seal start temperature, the better the low temperature sealing property, that is, the better the sealing property and the hot tack property.

Example 1:
[Cover material]
The surface resin layer (A) has a three-layer structure using the following three types of resins.
A1: Saponified ethylene-vinyl acetate copolymer (manufactured by Kuraray Co., Ltd., trade name “Eval E105”, hereinafter abbreviated as “EVOH”)
A2: 6-66 nylon resin (manufactured by DSM Japan Engineering Plastics Co., Ltd., trade name “Novamid 2030”, hereinafter abbreviated as “6-66Ny”)
A3: Olefin-based adhesive resin (manufactured by Mitsui Chemicals, trade name “Admer NF558”, hereinafter abbreviated as “AD1”)

  The pressure-sensitive adhesive resin layer (B) is a styrene-based thermoplastic elastomer resin (manufactured by Kuraray Co., Ltd., trade name “HIBLER 7311”, a styrene content of 12% by mass, a temperature indicating a peak value of loss tangent (tan δ) of −18.6 ° C. And a tan δ value of 0.19 at 20 ° C., hereinafter abbreviated as “TPS1”).

  The release resin layer (C) was configured using an amorphous polyamide resin (trade name “Novamid X21” manufactured by DSM Japan Engineering Plastics Co., Ltd.).

  The heat seal resin layer (D) has a Vicat softening point of 98 ° C., a peak value of weight average molecular weight measured by a high temperature GPC method of 445,000, and a polydispersity that is a ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn). Random polypropylene adhesive resin (hereinafter abbreviated as “AD2”) manufactured using a metallocene catalyst having a degree (Mw / Mn) of 1.8, 500 ppm of erucic acid amide as a lubricant, and as an antiblocking agent A resin composition in which 1000 ppm of natural silica was added and mixed was used.

  (A) Extruder for layer (single screw extruder of 50 mm in diameter for all three layers), (B) Extruder for layer (single screw extruder of 50 mm in diameter), (C) Extruder for layer (caliber) 50 mm single-screw extruder), (D) T-die / chill roll co-extrusion multi-layer film production apparatus having a layer extruder (single-screw extruder with a diameter of 50 mm) is supplied to each extruder and set for extrusion. Co-extruded under the conditions of a temperature of 190 to 230 ° C. and a T die set temperature of 235 ° C., and the average of each layer in a six-layer configuration of (A1) / (A2) / (A3) / (B) / (C) / (D) A multilayer film (X1) having a thickness of 10 μm / 20 μm / 10 μm / 20 μm / 5 μm / 5 μm and a total thickness of 70 μm was obtained.

  Next, dry lamination of a biaxially stretched polyethylene terephthalate film (manufactured by Unitika Ltd., trade name “Embret PET”, thickness 16 μm) on the outermost layer side of the surface resin layer (A) of the obtained multilayer film (X1) By laminating by the method, a laminate film (X1LF) having a total thickness of 86 μm was obtained and used as a cover material of the package.

  In addition, as an adhesive for dry lamination, a two-component curable adhesive (manufactured by Dainippon Ink Co., Ltd. as a main agent, trade name “Dick Dry LX-75A”, a trade name of Dainippon Ink Co., Ltd. “Dick Dry KW-40” was used.

[Bottom material]
From the outermost layer side, EVOH, 6-66Ny, AD1, random polyprolene resin (manufactured by Nippon Polypropylene Co., Ltd., trade name “Novatech PP EG7FTB”, hereinafter abbreviated as “PP1”) as a lubricant with 1000 ppm of erucamide is used. In addition, a resin composition (heat seal resin layer) in which 2000 ppm of natural silica was added and mixed as an antiblocking agent was laminated in this order, and each layer had an average thickness of 10 μm / 20 μm / 10 μm / 30 μm and a total thickness of 70 μm. A film (Y1) was obtained by a coextrusion method.

  An unstretched polyethylene terephthalate sheet (Mitsubishi Chemical Co., Ltd., trade name “Novaclear”) having a total thickness of 250 μm is bonded to the outermost layer side (EVOH surface) of this multilayer film (Y1) by a dry lamination method. A laminate sheet (Y1LS) having a thickness of 320 μm was obtained and used as the bottom material of the package. In addition, the grade similar to the case where a laminate film (X1LF) is produced was used as an adhesive for dry lamination.

[Deep-drawn packaging]
Using a deep-drawing packaging machine (manufactured by Mulchback, model number: R-530), the bottom material (Y1LS) is deep-drawn so that the non-stretched polyethylene terephthalate sheet layer is an outer layer, and the length is 130 mm. The container is processed into a rectangular container having a width of 170 mm and a flange width of 6 mm. In the heat seal portion, the above-mentioned lid material (X1LF) is applied to the flange portion provided on the deeply drawn bottom material, and the heat seal temperature (seal A deep-drawn package was produced by heat sealing under conditions of 150 ° C. (starting temperature), sealing time 2 seconds, and sealing pressure 4 kg / cm ² . The results of evaluation using this deep-drawn package are shown in Table 1 below.

Example 2:
[Cover material]
In the same manner as in Example 1, a laminate film (X1LF) was obtained and used as a lid for the package.

[Bottom material]
Example except that the resin used for the heat seal resin layer used in Example 1 was changed to homopolypropylene (manufactured by Nippon Polypro Co., Ltd., trade name “NOVATEC PP FB3HAT”, hereinafter abbreviated as “PP2”). 1, a resin composition (heat seal resin layer) in which EVOH, 6-66Ny, AD1, and PP2 are mixed with 1000 ppm of erucic acid amide as a lubricant and 2000 ppm of natural silica as an antiblocking agent from the outermost layer side. A multilayer film (Y2) having an average thickness of each layer of 10 μm / 20 μm / 10 μm / 30 μm and a total thickness of 70 μm was obtained by coextrusion.

  An unstretched polyethylene terephthalate sheet having a total thickness of 250 μm (product name “Novaclear”, manufactured by Mitsubishi Chemical Corporation) is bonded to the outermost layer side (EVOH surface) of the multilayer film (Y2) by a dry lamination method. A laminate sheet (Y2LS) having a thickness of 320 μm was obtained and used as a bottom material of the package. In addition, the grade similar to the case where a laminate film (X1LF) is produced was used as an adhesive for dry lamination.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1 except that the heat seal temperature was changed to a seal start temperature of 170 ° C. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 3:
[Cover material]
In the same manner as in Example 1, a laminate film (X1LF) was obtained and used as a lid for the package.
[Bottom material]
Example 1 except that the resin used in the heat seal resin layer used in Example 1 was changed to polyethylene (made by Nippon Polyethylene Co., Ltd., trade name “NOVATEC LL UF240”, hereinafter abbreviated as “LL”). In the same manner as above, from the outermost layer side, EVOH, 6-66Ny, AD1, and LLDPE were mixed with 1000 ppm of erucic acid amide as a lubricant and 2000 ppm of natural silica as an antiblocking agent in order of a resin composition (heat seal resin layer). A multilayer film (Y3) having an average thickness of each layer of 10 μm / 20 μm / 10 μm / 30 μm and a total thickness of 70 μm was obtained by coextrusion.

  An unstretched polyethylene terephthalate sheet having a total thickness of 250 μm (manufactured by Mitsubishi Chemical Corporation, trade name “Novaclear”) is bonded to the outermost layer side (EVOH surface) of this multilayer film (Y3) by a dry lamination method. A laminate sheet (Y3LS) having a thickness of 320 μm was obtained and used as the bottom material of the package. In addition, the grade similar to the case where a laminate film (X1LF) is produced was used as an adhesive for dry lamination.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1 except that the heat seal temperature was changed to a seal start temperature of 140 ° C. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 4:
[Cover material]
In Example 1, except that the resin used for the heat seal resin layer (D) was changed to a resin composition in which 90 parts by mass of AD2 used in Example 1 and 110 parts by mass of a random polypropylene resin “PP” were mixed. Is a 6-layer configuration of (A1) / (A2) / (A3) / (B) / (C) / (D) as in Example 1, and the average thickness of each layer is 10 μm / 20 μm / A multilayer film (X2) having a thickness of 10 μm / 20 μm / 5 μm / 5 μm and a total thickness of 70 μm was obtained. Next, in the same manner as in Example 1, a biaxially stretched polyethylene terephthalate film was bonded by a dry lamination method to obtain a laminate film (X2LF) having a total thickness of 86 μm, which was used as a lid for a package.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 5:
[Cover material]
A biaxially stretched polyethylene terephthalate film (manufactured by Unitika Ltd., trade name “Embret PET”, thickness 16 μm) is dried on the outermost layer side (EVOH surface) of the multilayer film (Y1) produced from the bottom material of Example 1 By laminating by a lamination method, a laminate film (Y1LF) having a total thickness of 86 μm was obtained and used as a cover material of a package.

[Bottom material]
On the outermost layer side (EVOH surface) of the multilayer film (X1) produced with the lid material of Example 1, an unstretched polyethylene terephthalate sheet having a total thickness of 250 μm (trade name “Novaclear” manufactured by Mitsubishi Chemical Corporation) was dried. By laminating by a lamination method, a laminate sheet (X1LS) having a total thickness of 320 μm was obtained and used as a bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 6:
[Cover material]
A biaxially stretched polyethylene terephthalate film (manufactured by Unitika Ltd., trade name “Embret PET”, thickness 16 μm) is dried on the outermost layer side (EVOH surface) of the multilayer film (Y2) produced from the bottom material of Example 2 By laminating by a lamination method, a laminate film (Y2LF) having a total thickness of 86 μm was obtained and used as a cover material of a package.

[Bottom material]
On the outermost layer side (EVOH surface) of the multilayer film (X1) produced with the lid material of Example 1, an unstretched polyethylene terephthalate sheet having a total thickness of 250 μm (trade name “Novaclear” manufactured by Mitsubishi Chemical Corporation) was dried. By laminating by a lamination method, a laminate sheet (X1LS) having a total thickness of 320 μm was obtained and used as a bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1 except that the heat seal temperature was changed to a seal start temperature of 140 ° C. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 1:
[Cover material]
In Example 1, the resin used for the heat seal resin layer (D) is a Vicat softening point of 78 ° C., the peak value of the weight average molecular weight measured by the high temperature GPC method is 385000, the weight average molecular weight (Mw) and the number average molecular weight. The polydispersity (Mw / Mn), which is the ratio of (Mn), is 2.4, except that it is changed to a random polypropylene adhesive resin (hereinafter abbreviated as “AD3”) manufactured using a metallocene catalyst. In the same manner as in Example 1, a six-layer structure of (A1) / (A2) / (A3) / (B) / (C) / (D), and the average thickness of each layer is 10 μm / 20 μm / 10 μm, respectively. A multilayer film (X3) having a thickness of / 20 μm / 5 μm / 5 μm and a total thickness of 70 μm was obtained.

  Subsequently, in the same manner as in Example 1, a biaxially stretched polyethylene terephthalate film base material was bonded by a dry lamination method to obtain a laminate film (X3LF) having a total thickness of 86 μm, and was used as a lid for a package.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 2:
[Cover material]
In Example 1, the resin used for the heat seal resin layer (D) has a Vicat softening point of 112 ° C., a peak value of the weight average molecular weight measured by the high temperature GPC method is 405000, the weight average molecular weight (Mw) and the number average molecular weight. The polydispersity (Mw / Mn), which is the ratio of (Mn), is 2.1, except that it is changed to a random polypropylene adhesive resin (hereinafter abbreviated as “AD4”) manufactured using a metallocene catalyst. In the same manner as in Example 1, a six-layer structure of (A1) / (A2) / (A3) / (B) / (C) / (D), and the average thickness of each layer is 10 μm / 20 μm / 10 μm, respectively. A multilayer film (X4) having a thickness of / 20 μm / 5 μm / 5 μm and a total thickness of 70 μm was obtained.

  Next, in the same manner as in Example 1, a biaxially stretched polyethylene terephthalate film was bonded by a dry lamination method to obtain a laminate film (X4LF) having a total thickness of 86 μm, which was used as a lid for a package.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1 except that the heat seal temperature was changed to a seal start temperature of 170 ° C. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 3:
[Cover material]
In Example 1, the resin used for the heat seal resin layer (D) is a Vicat softening point of 109 ° C., the peak value of the weight average molecular weight measured by the high temperature GPC method is 376000, the weight average molecular weight (Mw) and the number average molecular weight ( Except for changing to a random polypropylene-based adhesive resin (hereinafter abbreviated as “AD5”) manufactured using a Ziegler-Natta catalyst having a polydispersity (Mw / Mn) ratio of 2.5 of Mn). In the same manner as in Example 1, a six-layer structure of (A1) / (A2) / (A3) / (B) / (C) / (D), and the average thickness of each layer is 10 μm / 20 μm / 10 μm, respectively. A multilayer film (X5) having a thickness of / 20 μm / 5 μm / 5 μm and a total layer thickness of 70 μm was obtained.

  Next, in the same manner as in Example 1, a biaxially stretched polyethylene terephthalate film was bonded by a dry lamination method to obtain a laminate film (X5LF) having a total thickness of 86 μm, which was used as a lid for a package.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1 except that the heat seal temperature was changed to a seal start temperature of 170 ° C. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 4:
[Cover material]
A laminate film (X5LF) was obtained in the same manner as in Comparative Example 3, and used as a lid for the package.

[Bottom material]
As in Example 3, a laminate sheet (Y3LS) was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 5:
[Cover material]
In Example 1, the resin used for the adhesive resin layer (B) was changed from TPS1 to a styrene thermoplastic elastomer (manufactured by Asahi Kasei Co., Ltd., trade name “Tuftec H1052”, styrene content 20 mass%, loss tangent (tan δ) peak. (A1) / (A2) / in the same manner as in Example 1 except that the temperature was changed to −42.2 ° C., a tan δ value of 0.06 at 20 ° C., and hereinafter abbreviated as “TPS2”. (A3) / (B) / (C) / (D), a multilayer film having an average thickness of 10 μm / 20 μm / 10 μm / 20 μm / 5 μm / 5 μm and a total thickness of 70 μm. (X6) was obtained.

  Next, in the same manner as in Example 1, a biaxially stretched polyethylene terephthalate film was bonded by a dry lamination method to obtain a laminate film (X6LF) having a total thickness of 86 μm, which was used as a lid for a package.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 6:
[Cover material]
In Example 1, the resin used for the adhesive resin layer (B) was changed from TPS1 to styrene-based thermoplastic elastomer (styrene content: 20% by mass, loss tangent (tan δ) showing peak values of 2 ° C. and tan δ at 20 ° C. (A1) / (A2) / (A3) / (B) / (C) / (D) In the same manner as in Example 1 except that the value is changed to 0.07 (hereinafter abbreviated as “TPS3”). A multilayer film (X7) having an average thickness of 10 μm / 20 μm / 10 μm / 20 μm / 5 μm / 5 μm and a total thickness of 70 μm was obtained.

  Next, in the same manner as in Example 1, a biaxially stretched polyethylene terephthalate film was bonded by a dry lamination method to obtain a laminate film (X7LF) having a total thickness of 86 μm, which was used as a lid material for a package.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Reference example:
[Cover material]
In Example 1, in the six-layer configuration of (A1) / (A2) / (A3) / (B) / (C) / (D), the thickness of the release resin layer (D) was 40 μm, and the average thickness of each layer A multilayer film (X8) having a total thickness of 105 μm was obtained in the same manner as in Example 1 except that the thickness was changed to 10 μm / 20 μm / 10 μm / 20 μm / 5 μm / 40 μm.

  Next, in the same manner as in Example 1, a biaxially stretched polyethylene terephthalate film was bonded by a dry lamination method to obtain a laminate film (X8LF) having a total thickness of 121 μm, which was used as a lid for a package.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

From Table 1, the re-sealable packaging body (deep-drawing packaging body) formed with the lid or bottom material using the multilayer film defined in the present invention has an initial peel strength, a remaining layer and a reseal peel strength. It was confirmed that there was no problem in all the properties of slipperiness, blocking property, delamination strength, low temperature sealing property (contaminant sealing property and hot tack property), and excellent practicality (Examples 1 to 5). .
Further, it was confirmed that even if the heat seal resin layer of the body to be sealed (bottom material) was a polyethylene resin, it had a sufficient seal strength (initial peel strength). (Examples 2, 3, and 6).

On the other hand, a multilayer film in which a random polypropylene adhesive resin produced using a metallocene catalyst having a Vicat softening point of 78 ° C. and a weight average molecular weight peak of 385000 and a polydispersity of 2.4 is arranged on a heat seal resin layer The roll appearance at the time of slit processing was poor due to poor sliding property, and blocking occurred during high temperature storage (Comparative Example 1).
In addition, a multilayer in which a random polypropylene adhesive resin produced using a metallocene catalyst having a Vicat softening point of 112 ° C., a weight average molecular weight peak of 405000, and a polydispersity of 2.5 is disposed on the heat seal resin layer The film had low interlayer adhesion strength with the release resin layer (C), and the delamination phenomenon occurred. Moreover, the sealing start temperature was as high as 170 ° C., and the low temperature sealing properties (contaminant sealing properties and hot tack properties) were inferior (Comparative Example 2).

In addition, the multilayer film provided with a random polypropylene adhesive resin produced using a Ziegler-Natta catalyst having a Vicat softening point of 109 ° C. and a weight average molecular weight peak of 376000 and a polydispersity of 2.5 is poor in slipperiness and high temperature. Blocking also occurred during storage. Further, the sealing start temperature was as high as 170 ° C., and the low temperature sealing properties (contaminant sealing properties and hot tack properties) were inferior (Comparative Example 3).
Moreover, when the heat seal resin of the to-be-sealed body (bottom material) is a polyethylene resin, it was difficult to heat seal (Comparative Example 4).

When a styrenic thermoplastic elastomer having viscoelastic properties outside the range specified in the present invention was used for the adhesive resin layer, the reseal peel strength was insufficient (Comparative Examples 5 and 6).
When the total thickness of the release resin layer and the heat seal resin layer is increased (when exceeding 30 μm), the release resin layer and the heat seal resin layer cannot be broken when peeled by hand from the heat seal portion, and the object to be sealed A layer remained on the bottom material side (reference example).

DESCRIPTION OF SYMBOLS 1 Cover material 2 Bottom material 3 Cover resin surface resin layer 4 Cover material adhesive resin layer 5 Cover material peeling resin layer 6 Cover material heat seal resin layer 7 Bottom material surface resin layer 8 Bottom material heat seal resin layer DESCRIPTION OF SYMBOLS 9 Heat seal part of bottom material 10 Tab part of lid material 11 Exposed part of adhesive resin layer at the time of peeling 12 Exposed part of heat seal resin layer at the time of peeling 41 Bottom material 42 Lid material 43 Surface resin layer of bottom material 44 Bottom material Adhesive resin layer 45 Base material release resin layer 46 Base material heat seal resin layer 47 Surface resin layer of lid material 48 Heat seal resin layer of lid material 49 Heat seal part of lid material 50 Tab part of lid material 51 During peeling Exposed part of adhesive resin layer in 52 Exposed part of release resin layer during peeling

  The multilayer film of the present invention has excellent blocking resistance and good low-temperature sealing properties (contaminant sealing properties and hot tack properties) even if the heat seal resin of the package to be sealed is a propylene resin. Yes, it is excellent in hygiene, has good easy-openability, and has good resealability only by pressure and pressure bonding with hands and fingers. These advantages are very useful for the content manufacturing industry, the packaging manufacturing industry, and consumers in the packaging of foods and pharmaceuticals.

Claims (7)

A multilayer film in which a surface resin layer (A), an adhesive resin layer (B), a release resin layer (C), and a heat seal resin layer (D) are sequentially laminated is used as one of the lid or bottom material of the package. , A heat-sealing resin layer (D) of the multilayer film heat-sealed to the bottom material or lid material of the package body to be sealed, and in the heat-sealing part of the package body, the adhesive resin layer When (B) and the release resin layer (C) are delaminated, both layers are exposed in a resealable state, and the adhesive resin layer (B) is a dynamic viscoelasticity measurement. The temperature of the loss tangent (tan δ) measured at a frequency of 10 Hz is a layer composed mainly of a styrene thermoplastic elastomer having a temperature of −35 ° C. or more, and the heat seal resin layer (D) Vicat softening point is 80 ℃ The polydispersity (the upper limit is 105 ° C. or less, the peak value of the weight average molecular weight measured by the high temperature GPC method is 400,000 or more and 500,000 or less, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn)) A package comprising a layer composed mainly of a random polypropylene adhesive resin having a Mw / Mn) of 1.5 or more and 2.3 or less. The exposure of the pressure-sensitive adhesive resin layer (B) in the heat-sealed portion of the package is a breakage of the release resin layer (C) and the heat-seal resin layer (D) from the multilayer film, and the pressure-sensitive adhesive resin layer (B) and the release resin layer. The package according to claim 1, which is carried out by delamination with (C) and transfer of the release resin layer (C) and the heat seal resin layer (D) to the sealed body side.
The surface resin layer (A) is mainly composed of at least one thermoplastic resin selected from the group consisting of olefin resin, amide resin, saponified ethylene-vinyl acetate copolymer, ester resin, and styrene resin. The package according to claim 1, wherein a multilayer film configured as is used. The package according to any one of claims 1 to 3, wherein the release resin layer (C) uses a multilayer film composed mainly of an amide resin. The surface resin layer (A) is composed of two or more layers, and uses a multilayer film having a layer containing a saponified ethylene-vinyl acetate copolymer as a main component and / or a layer containing a polyamide-based resin as a main component. The package in any one of -4. The packaging body in any one of Claims 1-5 using the multilayer film whose sum total thickness of a peeling resin layer (C) and a heat seal resin layer (D) is 1 micrometer or more and 30 micrometers or less. The heat-seal resin layers (D) are overlapped and stored in a constant temperature layer at 40 ° C. for 24 hours, and after standing for 24 hours at 23 ° C. and 50% RH, the blocking force measured by ASTM D3354 is 3N or less. The package according to any one of claims 1 to 6.

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