JP2008150541A - Sealant film, laminated film and polypropylene container lid - Google Patents

Abstract

The present invention provides a sealant film having a degree of freedom in film forming conditions without requiring high material costs and having a stable seal, and a laminated film including the sealant film is an easy peel as a packaging material. In addition, it is possible to provide a lid that has an easy peel property and a stable sealing property of a polypropylene container.
A sealant film is formed by coextrusion lamination of a base material layer 2, an olefin-based cohesive failure layer 3, and a heat seal layer 3.
[Selection] Figure 1

Description

  The present invention relates to a sealant film, a laminate film, and a polypropylene container lid, and more particularly to an easy peel sealant film, a laminate film including the easy peel sealant film, and an easy peel lid for a polypropylene container.

The easy-peel sealant films currently on the market mainly include an interfacial release type sealant film, a cohesive failure type sealant film, and an delamination type sealant film. Interfacial release type sealant film is peeled off at the interface with the adherend, and the state after peeling is clean, but there are problems in terms of seal strength, heat resistance, stability, boil suitability and seal resistance are low There are drawbacks. The cohesive peeling type sealant film has a stable peel strength, but has a defect that cohesive failure marks remain on the adherend. The delamination type sealant film has both peel stability and seal stability, but has a drawback of leaving a thin skin on the adherend during peeling.
As described above, each of the three types of sealant films has advantages and disadvantages, and needs to be selected in consideration of the status of the product and necessary physical properties.
The cohesive fracture sealant film is composed of at least two layers, and the first layer serving as a sealing layer is composed of ethylene / methacrylic acid copolymer, ethylene / methyl methacrylate copolymer, ionomer, ethylene / acrylic acid copolymer. And at least one polymer selected from the group consisting of an ethylene / ethyl acrylate copolymer and an ethylene / methyl acrylate copolymer, and at least one selected from the group consisting of polyethylene, polypropylene and an ethylene / propylene copolymer. A layer containing a blend polymer with a polymer, the thickness and cohesive failure strength of the first layer being specified, and the second layer adjacent to the first layer is an ethylene / methacrylic acid copolymer, ethylene Methyl methacrylate copolymer, ionomer, ethylene / vinyl acetate Contains at least one polymer selected from the group consisting of copolymers, ethylene / acrylic acid copolymers, ethylene / ethyl acrylate copolymers, ethylene / methyl acrylate copolymers and maleic acid graft copolymers There is known an easy peel co-extruded laminated film in which the cohesive failure strength of the second layer is 1.5 times or more the cohesive failure strength of the first layer (see Patent Document 1).
Further, regarding the cohesive fracture sealant film, the base layer made of polypropylene is composed of an outer layer, an intermediate layer and a seal layer, and the seal layer is 50 to 90% by weight of ethylene / methacrylic acid copolymer and 10 to 50% by weight. A cushion layer made of a mixture of polypropylene and a sealant layer made of polyethylene, the sealant layer being 10 μm or less, and the ethylene / methacrylic acid copolymer melt flow rate A of the cushion layer and the melt of the sealant layer A multilayer film having a flow rate B of 1.5 ≦ B / A ≦ 5.0 is known (see Patent Document 2).
For the delaminating sealant film, a composition comprising a crystalline propylene random copolymer, polyethylene and olefin copolymer rubber is used as an intermediate layer (A), and a homogenous layer is formed on one side of the intermediate layer (A). A polypropylene-based multilayer film is known in which a crystalline propylene random copolymer layer (C) is laminated as a sealing layer on the other side of a polypropylene layer (B) (see Patent Document 3).
JP-A-5-212835 JP 2002-283513 A Japanese Patent Laid-Open No. 62-117741

However, the sealant films described in Patent Document 1 and Patent Document 2 have a high material cost, a low degree of freedom in film forming conditions (blending conditions, film forming methods, etc.), and a composition in which materials having different sealing layers are blended. Since it consists of a thing, it has the fault that stability of a seal is inadequate.
Moreover, although the sealant film described in Patent Document 3 has high sealing stability, delamination is destroyed due to strong sealing, and easy peel is lost, and the seal is weakly conscious of it. As a result, there is a concern that the thin film layer made of the crystalline propylene random copolymer as the seal layer may remain as a foreign substance on the adherend.
The problems to be solved by the present invention are a sealant film that does not require high material costs, has a degree of freedom in film forming conditions, and has a stable seal, a laminated film including the sealant film, and a polypropylene container It is to provide a cover material.

  The invention described in claim 1 solves the above-mentioned problems relating to the sealant film, and is summarized in a sealant film formed by coextrusion lamination of a base material layer, an olefin-based cohesive failure layer, and a heat seal layer.

In the present invention, the heat seal layer is made of polypropylene, desirably low melting point polypropylene. As the low melting point polypropylene, a metallocene random polypropylene having a melting point of 105 ° C. to 155 ° C., a random copolymer of propylene and other olefins such as ethylene and butene, and a block copolymer can be used. As a product, “Wintech WFX4TA” manufactured by Nippon Polypro Co., Ltd., “Novatech FW4BT” manufactured by Nippon Polypro Co., Ltd., etc., which are polypropylene random copolymers using a metallocene catalyst, can be used. The thickness of the heat seal layer is 0.5 to 10 μm, preferably 1 to 5 μm. If it exceeds 10 μm, the heat seal layer is not cut well and the easy peel property is impaired. On the other hand, if the thickness is less than 0.5 μm, the stability of the seal is deteriorated and it is easy to peel off, which is not preferable.
Further, the heat seal layer may be composed of a polyolefin resin instead of the low melting point polypropylene.

  According to the present invention, the olefin-based cohesive failure layer is a layer made of a polypropylene-based resin composition in which polypropylene and polyethylene are kneaded, and a high-density polyethylene-based, high-density polyethylene and polybutene-based resin are kneaded. It consists of a resin composition layer or a layer composed of a resin composition based on linear low density polyethylene and kneaded with linear low density polyethylene and polybutene resin, which requires high material costs. In addition, it is possible to provide a sealant film having a degree of freedom in film forming conditions and a stable seal.

  In the present invention, in the olefin-based cohesive failure layer, the blending ratio of the base polypropylene, high-density polyethylene or linear low-density polyethylene and the additive polyethylene, polybutene-based resin is not particularly limited, A preferred blending ratio is 70 parts base and 30 parts additive. In order to obtain cohesive failure, the melt index value of the base polypropylene, high density polyethylene or linear low density polyethylene and the melt index value of the additive polyethylene or polybutene resin must be 5 or more apart. is required.

  Invention of Claim 6 solves the subject regarding said laminated | multilayer film, The lamination | stacking which laminated | stacked at least one barrier film on the base material layer side of the sealant film in any one of Claim 1 thru | or 5. The gist is the film.

  Invention of Claim 7 solves the subject regarding said polypropylene container lid | cover material, and co-extrusion laminates the heat seal layer which consists of a base material layer, an olefin type cohesive failure layer, and a low melting point polypropylene. The gist is a polypropylene container lid made by laminating at least one barrier film on the base material layer side of the sealant film.

The sealant film of the present invention is formed by coextrusion lamination of a base material layer, an olefinic cohesive failure layer, and a heat seal layer. In that case, the olefinic cohesive failure layer is made of polypropylene, high-density polyethylene, or linear low Since it is composed of a resin composition in which polyethylene and polybutene-based resin are kneaded as a base with high density polyethylene, according to the present invention, high material costs are not required and film forming conditions are free. It is possible to provide a sealant film which has a high degree of sealing stability. The laminated film of the present invention can be used as a packaging material to form an easy peel packaging bag.
Moreover, the lid | cover material for polypropylene containers of this invention can be effectively utilized as a lid | cover material which has the easy peel property and stable sealing property of a polypropylene container.

  FIG. 1 shows a cross-sectional view of the sealant film of the present invention.

  As shown in FIG. 1, the sealant film 1 of the present invention is formed by coextrusion laminating a base material layer 2, an olefin-based cohesive failure layer 3, and a heat seal layer 4.

  The material of the base material layer 2 is a propylene resin such as a homopolymer of propylene or a copolymer of propylene and an α-olefin such as ethylene, etc., high density polyethylene, medium density polyethylene, low density polyethylene (LDPE) by high pressure polymerization method Select from a wide range of polyethylene resins such as ethylene-α / olefin copolymers polymerized using a multisite Ziegler-Natta catalyst, ionomers, polyamide resins, polyacrylic resins, polyvinyl chloride resins, polyester resins and others. Can do.

The olefin-based cohesive failure layer 3 is a layer made of a polypropylene-based resin composition kneaded with polypropylene and polyethylene, and a resin composition kneaded with high-density polyethylene and polybutene-based resin based on high-density polyethylene. It is comprised by the layer which consists of a resin composition which knead | mixed linear low density polyethylene and polybutene-type resin based on a layer or linear low density polyethylene. Thus, the polypropylene-based olefin-based cohesive failure layer 3 promotes peeling by simple cohesive failure. The olefin-based cohesive failure layer 3 based on high-density polypropylene or linear low-density polyethylene is obtained by adding a delamination factor together with cohesive failure.
Since the olefin-based cohesive failure layer 3 is made of the above-described material, it does not require a high material cost and has a degree of freedom in film forming conditions.

  In the present invention, in the olefin-based cohesive failure layer, the blending ratio of the base polypropylene, high-density polyethylene or linear low-density polyethylene and the additive polyethylene, polybutene-based resin is not particularly limited, A preferred blending ratio is 70 parts base and 30 parts additive. In order to obtain cohesive failure, the melt index value of the base polypropylene, high density polyethylene or linear low density polyethylene and the melt index value of the additive polyethylene or polybutene resin must be 5 or more apart. is required.

  The heat seal layer 4 is made of polypropylene, desirably low melting point polypropylene. As the low melting point polypropylene, a metallocene random polypropylene having a melting point of 105 ° C. to 155 ° C., a random copolymer of propylene and other olefins such as ethylene and butene, and a block copolymer can be used. As a product, “Wintech WFX4TA” manufactured by Nippon Polypro Co., Ltd., “Novatech FW4BT” manufactured by Nippon Polypro Co., Ltd., etc., which are polypropylene random copolymers using a metallocene catalyst, can be used. The thickness of the heat seal layer is 0.5 to 10 μm, preferably 1 to 5 μm. If it exceeds 10 μm, the sealing layer is not cut well and the easy peel property is impaired, which is not preferable. On the other hand, if the thickness is less than 0.5 μm, the stability of the seal is deteriorated and it is easy to peel off, which is not preferable.

  The heat seal layer 4 may be made of polyethylene resin instead of polypropylene resin.

  Next, in the present invention, a method for producing the sealant film 7 using the resin composition of each layer of the sealant film 1 will be described. First, a resin composition of each layer of the sealant film is prepared as described above, and then the resin composition is co-extruded using, for example, a T-die co-extrusion machine or an inflation co-extrusion machine. A three-layer three-layer sealant film 1 having a structure in which one layer is a base material layer 2, the second layer is an olefin-based cohesive failure layer 3, and the third layer is a heat seal layer 4 can be manufactured.

Next, in the present invention, the resin composition of each layer constituting the sealant film 1 will be described in more detail.
First, as a resin composition for forming the base material layer 2, for example, the above-described polypropylene resin or polyethylene resin, ionomer resin, polyamide resin, polyacrylic resin, polyvinyl chloride resin, polyester resin and the like are the main components. Furthermore, if necessary, when forming the film, for example, film processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slip properties, mold release properties, flame retardancy, For the purpose of improving and modifying the inertia, electrical characteristics, strength, etc., one or more kinds of various plastic compounding agents and additives are arbitrarily added, and if necessary, a solvent and a diluent. Etc. can be added and kneaded sufficiently to prepare the resin composition of the base material layer 2.

  Next, the resin composition for forming the olefin-based cohesive failure layer 3 includes base polypropylene, high-density polyethylene or linear low-density polyethylene, additive polyethylene, and polybutene resin, and if necessary. When forming a film, for example, film processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, mold release properties, flame retardancy, anti-glare properties, electrical properties For the purpose of improving and modifying strength and others, one or more kinds of various plastic compounding agents and additives are arbitrarily added, and if necessary, a solvent, a diluent, etc. are sufficiently added. And the resin composition of the olefin-based cohesive failure layer 3 can be prepared.

    Next, as the resin composition for forming the heat seal layer 4, polypropylene, in particular, a metallocene random polypropylene having a melting point of 105 ° C. to 155 ° C., a random copolymer of propylene and other olefins such as ethylene and butene, A block copolymer can be used, and as a commercial product, a polypropylene-based random copolymer using a metallocene catalyst, “Wintech WFX4TA” manufactured by Nippon Polypro Co., Ltd., “Novatech FW4BT” manufactured by Nippon Polypro Co., Ltd. Or a polyethylene-based resin, and if necessary, when forming the film, for example, film processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, release properties, etc. In order to improve and improve shape, flame retardancy, weather resistance, electrical properties, strength, etc. 1 to 2 or more types such as a pack compounding agent and an additive are optionally added, and if necessary, a solvent, a diluent and the like are added and kneaded sufficiently to form a first light-shielding adhesive resin layer 3 And the resin composition which forms the 2nd light-shielding adhesive resin layer 5 can be prepared.

Further, as the above-mentioned compounding agents and additives, specifically, it is possible to use a lubricant that itself has a lubricity and has a low migration in the resin. For example, liquid paraffin, white petrolatum, petroleum Waxes, such as waxes, microcrystalline wax, montan wax, and polyethylene wax, higher fatty acids having 8 to 22 carbon atoms, or higher fatty acids such as aluminum, higher fatty acid calcium, higher fatty acid magnesium, higher fatty acid zinc, and higher fatty acid lithium Fatty acids or metal salts thereof, linear aliphatic monohydric alcohols having 8 to 18 carbon atoms, aliphatic alcohols such as glycerin, glycerin, sorbitol, propylene glycol, pentaerythritol, triethylene glycol, and 4 to 22 carbon atoms Higher fatty acids and straight chain aliphatics with 8 to 18 carbon atoms Esters with trivalent alkoxide, tributyl acetylcitrate, di-2ethyl-hexyl adipate, azelaic acid-n-hexyl, ethanediol montanate, poly (1,3-butanediol adipic acid) ester, acetylricinoleic acid Methyl, poly (1,3-butylene glycol, 1,4-butylene glycol, octyl alcohol adipate) ester, esters of sugar alcohol and fatty acid, hydrogenated edible oil, castor oil, palm acetyl wax, acetylated monoglyceride, etc. Glycerides, having 16 to 18 carbon atoms, such as ethylene bis fatty acid amides represented by ethylene bis oleyl amide, higher fatty acid amides having 8 to 22 carbon atoms, stearyl erucamide, erucic acid amide, oleyl palmitoamide, etc. High grade fat Amides, other silicone oils such as methylhydrodiene polysiloxane, dimethylpolysiloxane, methylphenylphenylpolysiloxane, polyoxyalkylene, dimethylpolysiloxane, methylphenylpolysiloxane, polyoxyalkylene, dimethylpolysiloxane, rosin and maleic acid One type or two or more types such as glycerin ester of modified rosin can be used.
In the present invention, among the lubricants as described above, erucic acid amide, ethylene bis oleyl amide, stearic acid amide, oleic acid amide, methylene bis stearic acid amide, etc. themselves have lubricity and are extremely effective. Material.

  Next, a laminated film using the above sealant film will be described.

  FIG. 2 shows an embodiment of the laminated film of the present invention. FIG. 3 shows another embodiment of the laminated film of the present invention.

A laminated film 5 shown in FIG. 2 is provided with a laminating adhesive layer 7 on the side of the base material layer 2 of a sealant film 1 formed by coextrusion laminating a base material layer 2, an olefin-based cohesive failure layer 3 and a heat seal layer 4. The barrier film 6 is laminated.
3 has a laminating adhesive layer 7 on the side of the base material layer 2 of the sealant film 1 formed by co-extrusion laminating the base material layer 2, the olefin-based cohesive failure layer 3 and the heat seal layer 4. The first barrier film 6a is laminated, and the second barrier film 6b is laminated on the first barrier film 6a via the laminating adhesive layer 7.

Thus, the barrier films 6, 6a and 6b have excellent mechanical, physical, chemical and other properties, are excellent in strength, toughness, etc., and further have heat resistance, moisture resistance, and pin resistance. A resin film excellent in hole property, puncture resistance, transparency and the like can be used.
Specifically, for example, films of polyester resins, polyamide resins, polyaramid resins, polyethylene resins, polypropylene resins, polycarbonate resins, polyacetal resins, fluorine resins, and other various resins can be used.
Thus, as the resin film, either an unstretched film or a stretched film stretched in a uniaxial direction or a biaxial direction can be used.
In addition, the above film may have a thickness that keeps strength, puncture resistance, rigidity, etc. to the minimum necessary. If it is too thick, there is a disadvantage that the cost increases. , Puncture resistance, rigidity and the like are not preferable.
For the reasons described above, the thickness of the barrier film 6 is most preferably about 10 μm to 100 μm, preferably about 12 μm to 50 μm.
Among the above-described resin films or sheets, a biaxially stretched polyester film, a biaxially stretched polyamide film, or a biaxially stretched polypropylene resin film having a thickness of about 9 μm to 30 μm is particularly preferable.

Next, in the present invention, as the barrier films 6, 6a, 6b, for example, a material having a property of blocking light such as sunlight or a property of not transmitting gas such as water vapor, water, oxygen, etc. is used. This can be not only a single film, but also a composite film in which two or more materials are combined.
Specifically, for example, a resin film having a deposited film of an inorganic oxide such as silicon oxide or aluminum oxide having a barrier property, low density polyethylene having a barrier property such as water vapor or water, medium density polyethylene, high density polyethylene, direct Resin film such as chain low density polyethylene, polypropylene, ethylene-propylene copolymer, gas barrier property polyvinyl alcohol, ethylene-vinyl acetate copolymer saponified product, resin film such as nylon MXD6, pigment on resin, etc. Various colored resin films having a light-shielding property obtained by kneading a colorant and the like into a film can be used.
The thickness of the barrier films 6, 6a, 6b is usually about 5 μm to 300 μm, preferably 10 μm to 100 μm.

  Further, examples of the resin film that supports the above-described deposited film include polyester film, polyamide film, polyolefin, polyvinyl chloride film, polycarbonate film, polyvinylidene chloride film, polyvinyl alcohol film, and ethylene-vinyl acetate copolymer saponification. A physical film or the like can be used.

As the inorganic oxide constituting the vapor-deposited layer of inorganic oxide, for example, silicon oxide (SiO _x ), aluminum oxide, indium oxide, tin oxide, zirconium oxide and the like can be used.
Furthermore, a mixture of silicon monoxide and silicon dioxide or a mixture of silicon oxide and aluminum oxide can be used as the inorganic oxide.
In the present invention, as a method for forming a thin film layer of an inorganic oxide, a vacuum deposition method such as an ion beam method or an electron beam method, a sputtering method, or the like can be employed.
In order to obtain a sufficient barrier property, the thickness of the inorganic oxide thin film layer is usually preferably from 100 to 2000 mm, and particularly preferably from 200 to 1500 mm in the present invention. When the thickness of the thin film layer of the inorganic oxide exceeds 1500 mm, particularly when it exceeds 2000 mm, cracks and the like easily enter the vapor-deposited layer of the inorganic oxide, and there is a risk that the barrier property is lowered. It is not preferable because there is a problem that the material cost becomes high. Also, when it is less than 200 mm, particularly less than 100 mm, it is difficult to recognize the barrier effect of the thin film layer of the inorganic oxide, which is not preferable.

In the present invention, the barrier films 6, 6 a, 6 b have the property that they do not adsorb fragrance components contained in the packaged contents to be packaged, have a high fragrance retention property, and do not cause a taste change or a strange odor. A resin film can be used.
Specifically, for example, polyacrylic resin, polymethacrylic resin, polyacrylonitrile resin, polymethacrylonitrile resin, polystyrene resin, polycarbonate resin, polyethylene terephthalate resin or part of its ethylene component and / or terephthalate component Polyester resin such as polyethylene naphthalate resin, polyamide resin, saponified ethylene-vinyl acetate copolymer, polyvinyl alcohol resin, polyvinyl chloride Resin film, polyvinylidene chloride resin and other resin films can be used.
Thus, in the present invention, among the resin films described above, it is desirable to use a resin film that has a fragrance retention property and a barrier property against oxygen gas, water vapor, and the like. -It is desirable to use a resin film made of a saponified vinyl acetate copolymer, a polyamide-based resin, a polyacrylonitrile-based resin, a polyester-based resin or the like and having a high aroma retaining property and a barrier property.

On the base material layer 2 or the barrier film 6 of the sealant film 1 of the present invention, printing layers such as letters, figures, symbols, and patterns can be provided.
Specifically, the printing layer is mainly composed of an ink vehicle composed of one or more resins such as a resin, and if necessary, a plasticizer, a stabilizer, an antioxidant, a light stabilizer, an ultraviolet ray. Add one or more of absorbers, curing agents, cross-linking agents, lubricants, antistatic agents, fillers and other additives, add colorants such as dyes and pigments, solvent, dilute Add an agent, etc., and knead well to prepare an ink composition. Then, using this ink composition, for example, gravure printing, offset printing, letterpress printing, screen printing, transfer printing, flexographic printing and other printing Depending on the method, printing of characters, figures, symbols, patterns, and the like can be performed on the base material layer 2 or the barrier film 6 of the sealant film 1.

  As the ink vehicle, known ones such as linseed oil, tung oil, soybean oil, hydrocarbon oil, rosin, rosin ester, rosin modified resin, shellac, alkyd resin, phenolic resin, maleic resin, natural resin, carbonized Hydrogen resin, polyvinyl chloride resin, polyvinyl acetate resin, polystyrene resin, polyvinyl butyral resin, acrylic or methacrylic resin, polyamide resin, polyester resin, polyurethane resin, epoxy resin, urea resin, melamine resin Amino alkyd resins, phenol resins, nitrocellulose, ethyl cellulose, chlorinated rubber, cyclized rubber, and other one or more types can be used.

Next, the laminating adhesive layer 7 will be described.
Examples of the laminating adhesive include, for example, polyvinyl acetate adhesive, homopolymers such as ethyl acrylate, butyl, 2-ethylhexyl ester, and copolymers thereof with methyl methacrylate, acrylo-tolyl, styrene, etc. Polyacrylic acid ester adhesives, cyanoacrylate adhesives, ethylene copolymer adhesives made of copolymers of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid, etc., cellulose Adhesive, polyester adhesive, polyamide adhesive, polyimide adhesive, amino resin adhesive made of urea resin or melamine resin, phenolic resin adhesive, epoxy adhesive, polyurethane adhesive, reaction Mold (meth) acrylic adhesive, chloroprene rubber, nitrile rubber Styrene - rubber adhesive comprising a butadiene rubber, a silicone-based adhesive, an alkali metal silicate, may be used an inorganic adhesive or other adhesives such as low melting glass. The composition system of these adhesives may be any form such as an aqueous type, a solvent type, an emulsion type, and a dispersion type. Further, the shape may be any of film / sheet, powder, solid and the like. Further, the adhesion mechanism may be any form such as a chemical reaction type, a solvent volatilization type, a heat melting type, and a hot pressure type.
Thus, the laminating adhesive can be applied by, for example, a roll coating method, a gravure roll coating method, a kiss coating method, or other coating methods or printing methods. The coating amount of the laminating adhesive is desirably about 0.1 to 10 g / m ² (dry state).

  As a method of laminating the barrier film 6 on the base material layer 2 side of the sealant film 1, instead of the dry laminating method, an adhesion assistant layer such as a primer layer or an anchor coat layer, a melt-extruded resin layer, etc. are provided and then bonded. A melt extrusion lamination method in which the barrier film 6 is laminated on the base material layer 2 side of the sealant film 7 through an auxiliary layer and a melt extrusion resin layer can also be adopted.

  In the present invention, as the primer layer, for example, polyurethane resin, polyester resin, polyamide resin, epoxy resin, phenol resin, (meth) acrylic resin, polyvinyl acetate resin, polyolefin such as polyethylene or polypropylene The primer layer can be used by using a resin composition comprising a main resin or a copolymer or modified resin thereof, a cellulose resin or the like as a main component.

In the present invention, as the anchor coating agent, for example, organic titanium-based, isocyanate-based, polyethyleneimine-based, polybutadiene-based and other various aqueous or oil-based anchor coating agents such as alkyl titanates can be used. In that case, the coating amount of the anchor coating agent is desirably about 0.1 to 5 g / m ² (dry state).

A method of making a packaging bag using the laminated film 5 of the present invention will be described. The laminated film 5 as described above is used as a packaging material, and the laminated film is folded so that the heat-seal layer surface is on the inside, or two square laminated films are so that the heat-seal layer surface is on the inside. Various types of packaging bags can be manufactured by overlapping and further heat-sealing the peripheral edge. In this case, the side seal type, two-side seal type, three-side seal type, four-side seal type, envelope-attached seal type, jointed seal type (pillow seal type), pleated seal type, flat bottom seal type , Square bottom seal type and others.
In addition, a self-supporting packaging bag (standing pouch) can also be manufactured.
Moreover, heat sealing can be performed by well-known methods, such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, an ultrasonic seal, for example.
Note that, for example, a one-piece type, a two-piece type, other spout, an opening zipper, or the like can be arbitrarily attached to the packaging bag.

FIG. 4 shows a state in which the lid 9 made of the laminated film of the present invention is sealed at the opening of the polypropylene cup container 10. In that case, aiming at complete adhesion of the heat seal layer 4 of the laminated film 5 to the polypropylene cup container 10, the laminated film 5 composed of polypropylene, preferably low melting point polypropylene, is effective as a lid for polypropylene containers. It can be used. This polypropylene container lid material has a stable sealing property with respect to the polypropylene cup container 10 and an appropriate easy peel property.
FIG. 5 shows that the polypropylene container lid material 9 is cut from the polypropylene cup container 10 sealed with the polypropylene container lid material 9 as described above, and the heat seal layer 4 of the polypropylene container lid material 9 is broken. The state where the system cohesive failure layer 3 is broken and peeled is shown.

  Next, the present invention will be described in detail with reference to examples.

In carrying out top blown inflation coextrusion film formation of three types and three layers, materials of three layers were prepared as follows.
As the first layer resin composition, a base layer resin composition comprising 100 parts by weight of a polypropylene resin (Novatec FW4BT manufactured by Nippon Polypro Co., Ltd., density = 0.900 g / cm ³ , MFR = 6.5 g / 10 min) Was prepared.
As the resin composition for the second layer, 70 parts by weight of a polypropylene resin (Novatec FL02C manufactured by Nippon Polyethylene Co., Ltd., density = 0.900 g / cm ³ , MFR = 18 g / 10 min) and a low density polyethylene resin (Nippon Polyethylene Co., Ltd.) 30 parts by weight of Novatec LC522 (density = 0.923 g / cm ³ , MFR = 3.7 g / 10 min) were sufficiently kneaded to prepare a resin composition for an olefin-based cohesive failure layer.
As a resin composition for the third layer, a low melting point polypropylene resin (Wing WFX4TA manufactured by Nippon Polypro Co., Ltd., density = 0.900 g / cm ³ , MFR = 7.0 g / 10 minutes) 100 parts by weight resin for heat seal layer A composition was prepared.
Using a three-type three-layer T-die co-extrusion film forming machine, a total thickness of 30 μm of three layers consisting of a resin composition for a first layer 22 μm, a resin composition for a second layer 5 μm, and a resin composition for a third layer 3 μm A light-shielding laminated sealant film was obtained.
The surface of the first layer of the obtained light-shielding laminated sealant film is subjected to corona treatment, and a two-component curable urethane adhesive (main agent: polyester polyol, curing agent: aliphatic isocyanate) is applied to the surface, and a polyester film ( Two layers of Toyobo Co., Ltd. biaxially stretched PET film [E5200], double-sided treatment, thickness 12 μm) and polyester film (Toyobo Co., Ltd. biaxially stretched PET film [E5100], single-sided treatment, thickness 12 μm) are bonded together. A laminated film was obtained.
Using this laminated film as a lid, the water is sealed on a flange of a polypropine cup container filled with water with a flat seal under conditions of a seal temperature of 200 ° C., a seal pressure of 1 kg / cm ² , and a seal time of 1 second. A cup container filled with was prepared. After sealing, there was no leakage of the package contents or tearing of the lid. Furthermore, a drop test from a height of 1 m was performed three times, but no tearing, leakage, etc. were observed on the lid. Moreover, as a result of the peeling test of the cover material, a part of the heat seal layer was broken, and then the cohesive failure of the olefin-based cohesive failure layer occurred, and the cover material could be peeled with a good peel feeling. Moreover, the lid material was not torn or torn at the time of peeling, and the stringing of the heat seal layer was not observed.
Moreover, when the line seal (ring seal) performed at a high pressure was performed, the heat seal layer was not broken and showed a very stable peel behavior.

In carrying out top blown inflation coextrusion film formation of three types and three layers, materials of three layers were prepared as follows.
As a resin composition for the first layer, an ethylene-α-olefin copolymer polymerized using a single-site catalyst (metallocene catalyst) (Evolue SP2020 manufactured by Sumitomo Mitsui Chemicals, density = 0.916 g / cm ³ , A resin composition for a base layer comprising 100 parts by weight of MFR = 1.5 g / 10 min) was prepared.
As the resin composition for the second layer, 70 parts by weight of high-density polyethylene (Novatec HJ580 manufactured by Nippon Polyethylene Co., Ltd., density = 0.960 g / cm ³ , MFR = 11 g / 10 min) and polybutene resin (ethylene-propylene-) Copolymer resin of butene 1: 30 parts by weight of Tuffmer BL400 manufactured by Mitsui Chemicals Co., Ltd., density = 0.915 g / cm ³ , MFR = 1.8 g / 10 min) was sufficiently kneaded and a resin composition for an olefin-based cohesive failure layer Was prepared.
As a resin composition for the third layer, a low melting point polypropylene resin (Wing WFX4TA manufactured by Nippon Polypro Co., Ltd., density = 0.900 g / cm ³ , MFR = 7.0 g / 10 minutes) 100 parts by weight resin for heat seal layer A composition was prepared.
Using a three-layer, three-layer top-blown air-cooled inflation coextrusion film forming machine, the total thickness of the three layers comprising the first layer resin composition 22 μm, the second layer resin composition 5 μm, and the third layer resin composition 3 μm A 30 μm light-shielding laminated sealant film was obtained.
The surface of the first layer of the obtained light-shielding laminated sealant film is subjected to corona treatment, and a two-component curable urethane adhesive (main agent: polyester polyol, curing agent: aliphatic isocyanate) is applied to the surface, and a polyester film ( Two layers of Toyobo Co., Ltd. biaxially stretched PET film [E5200], double-sided treatment, thickness 12 μm) and polyester film (Toyobo Co., Ltd. biaxially stretched PET film [E5100], single-sided treatment, thickness 12 μm) are bonded together. A laminated film was obtained.
Using this laminated film as a lid, the flange of a polypropylene cup container filled with water is sealed with a flat seal under conditions of a seal temperature of 200 ° C., a seal pressure of 1 kg / cm ² , and a seal time of 1 second. A cup container filled with was prepared. After sealing, there was no leakage of the package contents or tearing of the lid. Furthermore, a drop test from a height of 1 m was performed three times, but no tearing, leakage, etc. were observed on the lid. In addition, as a result of the peeling test of the lid material, a part of the heat seal layer is broken, and then the cohesive failure of the cohesive failure layer and the delamination between the cohesive failure layer and the heat seal layer occur, and the lid material is improved. It was peelable with a peel feeling. Moreover, the lid material was not torn or torn at the time of peeling, and the stringing of the heat seal layer was not observed.
Moreover, when the line seal (ring seal) performed at a high pressure was performed, the heat seal layer was not broken and showed a very stable peel behavior.

In carrying out top blown inflation coextrusion film formation of three types and three layers, materials of three layers were prepared as follows.
As a resin composition for the first layer, an ethylene-α-olefin copolymer polymerized using a single-site catalyst (metallocene catalyst) (Evolue SP2020 manufactured by Sumitomo Mitsui Chemicals, density = 0.916 g / cm ³ , A resin composition for a base layer comprising 100 parts by weight of MFR = 1.5 g / 10 min) was prepared.
As the resin composition for the second layer, 70 parts by weight of high-density polyethylene (Novatec HJ590N manufactured by Nippon Polyethylene Co., Ltd., density = 0.960 g / cm ³ , MFR = 40 g / 10 min) and polybutene resin (ethylene-propylene-) Copolymer resin of butene 1: 30 parts by weight of Tuffmer BL400 manufactured by Mitsui Chemicals Co., Ltd., density = 0.915 g / cm ³ , MFR = 1.8 g / 10 min) was sufficiently kneaded and a resin composition for an olefin-based cohesive failure layer Was prepared.
As a resin composition for the third layer, a resin composition for a heat seal layer comprising 100 parts by weight of a polypropylene resin (Wing WFX4TA manufactured by Nippon Polypro Co., Ltd., density = 0.900 g / cm ³ , MFR = 7.0 g / 10 min) Was prepared.
Using a three-layer, three-layer top-blown air-cooled inflation coextrusion film forming machine, the total thickness of the three layers comprising the first layer resin composition 22 μm, the second layer resin composition 5 μm, and the third layer resin composition 3 μm A 30 μm light-shielding laminated sealant film was obtained.
The surface of the first layer of the obtained light-shielding laminated sealant film is subjected to corona treatment, and a two-component curable urethane adhesive (main agent: polyester polyol, curing agent: aliphatic isocyanate) is applied to the surface, and a polyester film ( Two layers of Toyobo Co., Ltd. biaxially stretched PET film [E5200], double-sided treatment, thickness 12 μm) and polyester film (Toyobo Co., Ltd. biaxially stretched PET film [E5100], single-sided treatment, thickness 12 μm) are bonded together. A laminated film was obtained.
Using this laminated film as a lid, the flange of a polypropylene cup container filled with water is sealed with a flat seal under conditions of a seal temperature of 200 ° C., a seal pressure of 1 kg / cm ² , and a seal time of 1 second. A cup container filled with was prepared. After sealing, there was no leakage of the package contents or tearing of the lid. Furthermore, a drop test from a height of 1 m was performed three times, but no tearing, leakage, etc. were observed on the lid. In addition, as a result of the peeling test of the lid material, a part of the heat seal layer is broken, and then the cohesive failure of the cohesive failure layer and the delamination between the cohesive failure layer and the heat seal layer occur, and the lid material is improved. It was peelable with a peel feeling. Moreover, the lid material was not torn or torn at the time of peeling, and the stringing of the heat seal layer was not observed.
Moreover, when the line seal (ring seal) performed at a high pressure was performed, the heat seal layer was not broken and showed a very stable peel behavior.

In carrying out top blown inflation coextrusion film formation of three types and three layers, materials of three layers were prepared as follows.
As the first layer resin composition, a base layer resin composition comprising 100 parts by weight of a polypropylene resin (Novatec FW4BT manufactured by Nippon Polypro Co., Ltd., density = 0.900 g / cm ³ , MFR = 6.5 g / 10 min) Was prepared.
As the resin composition for the second layer, 70 parts by weight of a polypropylene resin (Novatec FL02C manufactured by Nippon Polyethylene Co., Ltd., density = 0.900 g / cm ³ , MFR = 18 g / 10 min) and a low density polyethylene resin (Nippon Polyethylene Co., Ltd.) 30 parts by weight of Novatec LC522 (density = 0.923 g / cm ³ , MFR = 3.7 g / 10 min) were sufficiently kneaded to prepare a resin composition for an olefin-based cohesive failure layer.
As a resin composition for the third layer, a resin composition for a heat seal layer comprising 100 parts by weight of a polypropylene resin (Wing WFX4TA manufactured by Nippon Polypro Co., Ltd., density = 0.900 g / cm ³ , MFR = 7.0 g / 10 min) Was prepared.
Using a three-layer, three-layer top-blown air-cooled inflation coextrusion film forming machine, the total thickness of the three layers comprising the first layer resin composition 22 μm, the second layer resin composition 5 μm, and the third layer resin composition 3 μm A 30 μm light-shielding laminated sealant film was obtained.
The surface of the first layer of the obtained light-shielding laminated sealant film is subjected to corona treatment, and a two-component curable urethane adhesive (main agent: polyester polyol, curing agent: aliphatic isocyanate) is applied to the surface, and a polyester film ( Toyobo Co., Ltd. biaxially stretched PET film [E5200], double-sided treatment, thickness 12 μm) and polyester film (Dai Nippon Printing Co., Ltd. silica vapor-deposited stretched PET film [IB-PET-RB], single-sided treatment, thickness 12 μm) These two layers were bonded together to obtain a laminated film.
Using this laminated film as a lid, the flange of a polypropylene cup container filled with water is sealed with a flat seal under conditions of a seal temperature of 200 ° C., a seal pressure of 1 kg / cm ² , and a seal time of 1 second. A cup container filled with was prepared. After sealing, there was no leakage of the package contents or tearing of the lid. Furthermore, a drop test from a height of 1 m was performed three times, but no tearing, leakage, etc. were observed on the lid. Further, as a result of the peeling test of the lid material, a part of the heat seal layer was broken, and then the cohesive failure of the cohesive failure layer occurred, and the lid material could be peeled with a good peel feeling. Moreover, the lid material was not torn or torn at the time of peeling, and the stringing of the heat seal layer was not observed.
Moreover, when the line seal (ring seal) performed at a high pressure was performed, the heat seal layer was not broken and showed a very stable peel behavior.

[Experimental example]
About the laminated film of said Examples 1-4, (1) film thickness and (2) peel strength were measured and evaluated based on the measurement result.
(1) Measurement of film thickness This was measured from a cross-sectional photograph using a μ-meter manufactured by Sony Corporation.
(2) Measurement of peel strength The lid material was sealed into a polypropylene cup container under the conditions of a flat seal, a seal temperature of 200 ° C., a seal pressure of 1 kg / cm ² , and a seal time of 1 second. Next, a strip-shaped test piece having a width of 15 mm was cut out, and the tensile test was performed on the test piece at 300 mm / min using a tensile tester.

  As is clear from the measurement results shown in Table 1, the laminated films of Examples 1 to 4 can be peeled with an appropriate peel strength.

The sealant film of the present invention has sealing stability and can be peeled off at an appropriate peel strength. The laminated film including the sealant film is used as a packaging material to form an easy peel packaging bag. Can be provided.
Moreover, the polypropylene container lid made of the laminated film of the present invention can be effectively used as a lid having the easy peel property and stable sealing property of the polypropylene container.

It is an expanded sectional view of the sealant film of the present invention. It is an expanded sectional view of an embodiment of a laminated film of the present invention. It is an expanded sectional view of another embodiment of the laminated film of the present invention. It is a side view of the polypropylene cup container which sealed the opening part with the cover material which consists of laminated films of this invention. It is explanatory drawing which shows the state which peeled the cover material which consists of a laminated film of this invention from the cup container made from a polypropylene.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealant film 2 Base material layer 3 Olefin system cohesive failure layer 4 Heat seal layer 5 Laminated film 6, 6a, 6b Barrier film 7 Adhesive layer for laminating 9 Cover material which consists of laminated film of this invention 10 Polypropylene cup container

Claims (10)

  A sealant film obtained by coextrusion lamination of a base material layer, an olefinic cohesive failure layer, and a heat seal layer.   The sealant film according to claim 1, wherein the heat seal layer is made of a low melting point polypropylene.   The sealant film according to claim 1 or 2, wherein the olefin-based cohesive failure layer is made of a polypropylene-based resin composition in which polypropylene and polyethylene are kneaded.   The sealant film according to claim 1 or 2, wherein the olefin-based cohesive failure layer is made of a resin composition based on high-density polyethylene and kneaded with high-density polyethylene and polybutene resin.   The sealant film according to claim 1 or 2, wherein the olefin-based cohesive failure layer is made of a resin composition based on linear low-density polyethylene and kneaded with linear low-density polyethylene and polybutene-based resin.   A laminated film comprising at least one barrier film laminated on the base material layer side of the sealant film according to any one of claims 1 to 5.   A container for a polypropylene container made by laminating at least one barrier film on the base material layer side of a sealant film obtained by coextrusion laminating a heat seal layer made of a base material layer, an olefinic cohesive failure layer and a low melting point polypropylene. .   8. The polypropylene container lid according to claim 7, wherein the olefin-based cohesive failure layer comprises a polypropylene-based resin composition in which polypropylene and polyethylene are kneaded.   The olefin-based cohesive failure layer is made of a resin composition based on high-density polyethylene and kneaded with high-density polyethylene and a polybutene-based resin. The sealant film according to claim 7, wherein the olefin-based cohesive failure layer is formed of a resin composition based on linear low-density polyethylene and kneaded with linear low-density polyethylene and a polybutene resin.

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