Packaging material for tube container, tube container and method for manufacturing resin pellet

Abstract

To provide a packaging material for a tube container, a tube container and a method for manufacturing a resin pellet, which can reduce environmental loads.SOLUTION: A packaging material 10 for a tube container includes a first sealant layer 11, a peeling layer 12, and a second sealant layer 13, which are arranged in order from an outer surface 101 to an inner surface 102. At least 90% or more of the first sealant layer 11 is the same resin-based material. The peeling layer 12 is composed of a material dissolvable in water.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a packaging material for tube containers, a tube container, and a method for producing resin pellets. [Background technology]

[0002] Conventionally, tubular containers including aluminum foil have been known (for example, Patent Document 1). Patent Document 1 discloses a tubular container that can suppress the occurrence of wrinkles in the aluminum foil layer at the side seam portion when the side seam is made into a cylindrical body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-187819 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, such tube containers containing aluminum foil are generally incinerated without recycling the resin.

[0005] On the other hand, in recent years, there has been an increasing demand for the creation of a recycling-oriented society, and therefore, there is a demand for reducing the environmental load by recycling resins from tube containers by various methods.

[0006] The present disclosure has been made in consideration of these points, and aims to provide a packaging material for tube containers, a tube container, and a method for producing resin pellets that are capable of reducing the environmental impact. [Means for solving the problem]

[0007] The embodiments of the present disclosure relate to the following [1] to [6].

[0008] [1] The sealant includes a first sealant layer, a release layer, and a second sealant layer, which are arranged in this order from the outer surface to the inner surface, At least 90% of the first sealant layer is made of the same resin-based material; The packaging material for tube containers, wherein the release layer is made of a material that dissolves in water.

[0009] [2] The packaging material for tube containers according to [1], wherein the second sealant layer contains a material of the same resin system.

[0010] [3] The packaging material for tube containers according to [1] or [2], further comprising a base material layer provided between the release layer and the second sealant layer.

[0011] [4] The packaging material for tube containers according to any one of [1] to [3], further comprising a barrier layer provided between the release layer and the second sealant layer.

[0012] [5] The packaging material for tube containers according to any one of [1] to [4], wherein at least one of the first sealant layer and the second sealant layer contains a biomass-derived resin.

[0013] [6] In a tube container, [1] to [5], and a body tube having the packaging material for a tube container according to any one of the above. a head member joined to one end of the body tube.

[0014] [7] A method for producing resin pellets, comprising the steps of: A step of recovering the packaging material for tube containers according to any one of [1] to [5] or the tube container according to [6]; A step of crushing the collected tube container packaging material or the tube container; a step of agitating the crushed tube container packaging material or the tube container in water to dissolve the release layer, thereby separating the first sealant layer from the second sealant layer and removing foreign matter from the first sealant layer; drying and screening the first sealant layer separated from the second sealant layer; pulverizing the selected first sealant layer; Melting the pulverized first sealant layer; forming a resin pellet from the molten first sealant layer; and cooling the resin pellets. Effect of the Invention

[0015] According to the present disclosure, the environmental burden can be reduced. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing a resin pellet according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a packaging material for tube containers according to one embodiment. [Diagram 3] FIG. 3 is a cross-sectional view showing a packaging material for tube containers according to one embodiment. [Figure 4] FIG. 4 is a partial vertical cross-sectional view showing a tube container according to one embodiment. [Diagram 5] FIG. 5 is a flow chart illustrating a recycling method and a method for producing resin pellets according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] An embodiment will be described below with reference to the drawings. FIGS. 1 to 5 are diagrams showing an embodiment. Each of the figures shown below is a schematic diagram. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, the present invention can be modified appropriately within the scope of the technical concept. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed explanations may be omitted. In addition, the numerical values ​​such as the dimensions of each member and the material names described in this specification are examples of an embodiment, and are not limited to these and can be appropriately selected and used. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and vertical, are interpreted to include substantially the same state in addition to their strict meanings.

[0018] First, with reference to FIG. 1, the structure of a resin pellet 1 produced by the recycling method and the method for producing resin pellets according to the present embodiment will be described.

[0019] <Resin pellets> As shown in Fig. 1, the resin pellet 1 is a resin lump with a maximum width of about 1 mm to 7 mm. In the illustrated example, the resin pellet 1 has a cylindrical shape. Although not shown, the resin pellet 1 may have a spherical shape. The resin pellet 1 is a resin lump produced by cutting extruded resin (strands) extruded in a string shape from a filter into granules in a pellet production device (not shown).

[0020] The resin pellets 1 contain recycled resin (hereinafter, simply referred to as recycled resin). This can reduce the environmental impact of the tube container packaging material 10 and the like produced from the resin pellets 1. In this specification, the term "recycled resin" refers to a resin material obtained by removing foreign matter and dirt from a resin body. The resin body may be a resin product used in the market (a tube container 40 described later), or a material generated in a resin product manufacturing process before it is released to the market (a tube container packaging material 10 described later). In other words, the recycled resin may be a resin obtained by post-consumer recycling (PCR), or may be a resin obtained by post-industrial recycling (PIR). In addition, when the recycled resin is produced by post-consumer recycling (PCR), the recycled resin may be a resin recycled from another tube container 40 produced from the resin pellets 1.

[0021] When obtaining recycled resin, first, a resin body (a tube container packaging material 10 or a tube container 40 described later) is selected and crushed. Then, foreign matter is removed from the crushed resin body. As a result, flakes from which foreign matter has been removed are obtained. At this time, if necessary, the crushed resin body may be washed with water, hot water, a surfactant, an alkaline cleaning solution, or the like to remove dirt adhering to the flakes. In this case, for example, an aqueous solution of a mixture of a surfactant and an alkaline cleaning solution may be heated to about 80°C, and the crushed resin body may be washed with the aqueous solution. Then, the flakes are further treated at high temperature and reduced pressure for a certain period of time to obtain a resin material from which foreign matter and dirt have been removed (i.e., recycled resin).

[0022] In this embodiment, at least 90% or more of the recycled resin is a material of the same resin system. In this case, the recycled resin can be classified as a so-called mono-material material, and can be suitably used for manufacturing a packaging container (so-called mono-material packaging container) made of the same material. In addition, the recycled resin (resin pellets 1) is made from a mono-material material (a packaging material 10 for a tube container described later) or a mono-material packaging container (a tube container 40 described later). This makes it possible to easily increase the content of the material of the same resin system in the recycled resin (resin pellets 1). The material constituting the recycled resin may be polyolefin. Specifically, the material constituting the recycled resin may be polyethylene or polypropylene. In other words, the resin pellets 1 may contain polyethylene or polypropylene as a main component.

[0023] Here, for example, polyethylene includes high-density polyethylene and linear low-density polyethylene. These high-density polyethylene and linear low-density polyethylene are classified as "materials of the same resin system" in this specification. On the other hand, for example, polyethylene and polyester are not classified as materials of the same resin system.

[0024] The resin pellets 1 may further contain an ethylene-vinyl alcohol copolymer (EVOH). In a packaging material for a tube container constituting the body tube of a tube container, a layer containing an ethylene-vinyl alcohol copolymer may be provided as a barrier layer. Therefore, when the resin pellets 1 are produced from such a tube container, the resin pellets 1 contain an ethylene-vinyl alcohol copolymer. In this case, the content of the ethylene-vinyl alcohol copolymer in the resin pellets 1 may be 5% by weight or less.

[0025] Furthermore, the resin pellets 1 may further contain metal particles. In the packaging material for a tube container constituting the body tube of the tube container, a metal foil (e.g., aluminum foil, etc.) or a vapor-deposited film of a metal (e.g., aluminum, etc.) may be provided as a barrier layer. Therefore, when the resin pellets 1 are produced from such a tube container, the resin pellets 1 contain metal particles. In this case, the content of the metal particles in the resin pellets 1 may be 1% by weight or less.

[0026] The resin pellets 1 may be produced by a so-called hot cut method in which the molten resin is cut in a molten state without being cooled. Alternatively, the resin pellets 1 may be produced by a so-called cold cut method in which the molten resin is cut after being cooled. When cooling the molten resin in this way, a cooling method such as a water cooling method in which water is directly poured onto the molten resin, a mist cooling method in which water is turned into a mist and poured onto the molten resin, or an air cooling method in which air is blown onto the molten resin may be used.

[0027] Next, the tube container packaging material 10 according to this embodiment will be described.

[0028] <Packaging material for tube containers> 2 and 3, the tube container packaging material 10 includes a first sealant layer 11, a peelable layer 12, and a second sealant layer 13, which are arranged in this order from an outer surface 101 to an inner surface 102. The tube container packaging material 10 may further include a base layer 14 provided between the peelable layer 12 and the second sealant layer 13. The tube container packaging material 10 may further include a barrier layer 15 provided between the peelable layer 12 and the second sealant layer 13.

[0029] 2, the tube container packaging material 10 includes, in this order from an outer surface 101 to an inner surface 102, a first sealant layer 11, a first adhesive layer 16a, a peel layer 12, a base layer 14, a printed layer 17, a second adhesive layer 16b, a barrier layer 15, a third adhesive layer 16c, and a second sealant layer 13. In the tube container packaging material 10 shown in FIG. 2, the first sealant layer 11 constitutes the outer surface 101 of the tube container packaging material 10, and the second sealant layer 13 constitutes the inner surface 102 of the tube container packaging material 10.

[0030] 3, the tube container packaging material 10 includes, in this order from the outer surface 101 to the inner surface 102, a first sealant layer 11, a first adhesive layer 16a, a peel layer 12, a base material layer 14, a printed layer 17, a second adhesive layer 16b, a barrier layer 15, an intermediate layer 18, a third adhesive layer 16c, and a second sealant layer 13. In the tube container packaging material 10 shown in FIG. 3, the first sealant layer 11 forms the outer surface 101 of the tube container packaging material 10, and the second sealant layer 13 forms the inner surface 102 of the tube container packaging material 10.

[0031] Each layer of the tube container packaging material 10 will be described below.

[0032] <<First sealant layer>> The first sealant layer 11 is a layer for bonding together the tube container packaging materials 10. This first sealant layer 11 is a layer that becomes the outermost layer when a tube container 40, which will be described later, is produced from the tube container packaging material 10.

[0033] In this embodiment, at least 90% or more of the first sealant layer 11 is made of the same resin material. This makes it possible to increase the content of the same resin material in the recycled resin (resin pellets 1) produced from the tube container 40 when the tube container 40 described later is recycled.

[0034] The material constituting the first sealant layer 11 may be a material that melts and fuses by heat. In this case, the material constituting the first sealant layer 11 is a material of the same resin system as the material constituting the second sealant layer 13. The first sealant layer 11 may be made of, for example, polyolefin. More specifically, the first sealant layer 11 may be made of, for example, one or more resins such as acid-modified polyolefin resins obtained by modifying polyolefin resins such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), polypropylene, polyethylene, or polypropylene with acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, or other unsaturated carboxylic acids, polyvinyl acetate resins, polyester resins, polystyrene resins, polyacrylonitrile, saturated polyesters, or polyvinyl alcohol.

[0035] The first sealant layer 11 may contain a resin derived from biomass. For example, when the first sealant layer 11 contains polyethylene or polypropylene, the polyethylene may be biomass polyethylene, and the polypropylene may be biomass polypropylene. Since the first sealant layer 11 contains a resin derived from biomass, the amount of fossil fuel used can be reduced, and the environmental impact of the packaging material 10 for tube containers can be reduced. Note that biomass polyethylene is a monomer polymer containing ethylene derived from biomass. Since ethylene derived from biomass is used as the raw material monomer, the polyolefin obtained by polymerization is derived from biomass. The content of ethylene derived from biomass in the raw material monomer does not need to be 100% by mass, and is, for example, preferably 50% or more, more preferably 80% or more. The raw material monomer may contain ethylene derived from fossil fuel, and may contain α-olefin monomers such as butylene, hexene, and octene.

[0036] For example, biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from a plant raw material. The plant raw material is not particularly limited, and any conventionally known plant can be used. Examples of conventionally known plants include corn, sugarcane, beet, and manioc.

[0037] The first sealant layer 11 may also be composed of a film made from the above-mentioned resin pellets 1. In this case, the film may be made, for example, by using the resin pellets 1 and an inflation method or other molding method. The film made from the resin pellets 1 may contain recycled resin, and at least 90% of the recycled resin may be a material of the same resin system.

[0038] The film made from the above-mentioned resin pellets 1 may further contain an ethylene-vinyl alcohol copolymer. In this case, the content of the ethylene-vinyl alcohol copolymer in the film may be 5% by weight or less.

[0039] The film may further contain metal particles. In this case, the content of the metal particles in the film may be 1% by weight or less.

[0040] Furthermore, the film may further contain virgin resin. Note that "virgin resin" refers to a resin material that has not been subjected to a recycling process. By containing virgin resin in the film in this way, the hygiene of the film can be improved.

[0041] The material for the first sealant layer 11 may be a material to which, for example, an antiblocking agent, a lubricant (fatty acid amide, etc.), a flame retardant, an inorganic or organic filler, etc. are optionally added.

[0042] In the present embodiment, the thickness of the first sealant layer 11 is preferably not less than 50 μm and not more than 250 μm.

[0043] <<Release layer>> The release layer 12 is a layer for peeling the first sealant layer 11 and the second sealant layer 13 from each other. The release layer 12 is made of a material that dissolves in water. A coating agent or the like may be used as a material constituting the release layer 12. For example, hydroxypropyl cellulose or hypromellose may be used as the coating agent. As an example, the release layer 12 may be made of a coating agent in which a crosslinking agent is added to a vinyl alcohol resin.

[0044] The material constituting the release layer 12 may be a water-soluble polymer. The water-soluble polymer is a polymer that is soluble in water or an aqueous solvent at room temperature and normal pressure. The water-soluble polymer is, for example, a polymer that has a solubility in water of 1 (g / 100g) or more, preferably 5 (g / 100g) or more, at 23°C and 1 atm. The water-soluble polymer is preferably a polymer whose solubility in water is improved when water is heated to an appropriate temperature. The heating temperature may be, for example, 50°C or more and 100°C or less.

[0045] The water-soluble polymer is not particularly limited, and examples thereof include synthetic resins and natural polymers. Examples of the synthetic resin include polyvinyl alcohol-based resins such as polyvinyl alcohol or modified polyvinyl alcohol, polyvinyl acetate-based resins, cellulose-based resins, acrylic resins, polyacrylamide-based resins, polyethylene oxide-based resins, polyurethane-based resins, and amino-based resins. Examples of the natural polymer include polysaccharides such as starch or polypeptide, glue, casein, and natural rubber. The above-mentioned materials may be used alone or in combination of two or more.

[0046] The aqueous solvent is a mixed solvent containing water and a hydrophilic solvent. The hydrophilic solvent is a solvent that can be dissolved uniformly in water. Examples of the hydrophilic solvent include alcohols such as methanol, glycols such as ethylene glycol, cellosolves such as methyl cellosolve, and esters such as ethyl acetate.

[0047] Methods for forming the release layer 12 include, for example, roll coating, gravure coating, gravure reverse coating, microgravure coating, slot die coating, die coating, knife coating, inkjet coating, dispenser coating, kiss coating, spray coating, screen printing, offset printing, and flexographic printing.

[0048] In the present embodiment, the thickness of the release layer 12 is preferably not less than 2 μm and not more than 5 μm.

[0049] <<Second sealant layer>> The second sealant layer 13 is a layer for bonding the tube container packaging materials 10 together. For example, the second sealant layer 13 is a layer that becomes the innermost layer when a tube container 40 (described later) is produced from the tube container packaging material 10. The second sealant layer 13 is preferably made of a virgin resin. In this way, the second sealant layer 13 that becomes the innermost layer of the tube container 40 is made of a virgin resin, thereby improving the hygiene of the tube container 40.

[0050] The material constituting the second sealant layer 13 is a material that melts and fuses by heat. In this case, the second sealant layer 13 contains a material of the same resin type as that constituting at least 90% or more of the first sealant layer 11. That is, the material constituting the second sealant layer 13 is a material of the same resin type as that constituting the first sealant layer 11. For example, polyolefin may be used for the second sealant layer 13. More specifically, for example, the second sealant layer 13 may be a resin made of one or more of acid-modified polyolefin resins obtained by modifying polyolefin resins such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), polypropylene, polyethylene, or polypropylene with acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, or other unsaturated carboxylic acids, polyvinyl acetate resins, polyester resins, polystyrene resins, polyacrylonitrile, saturated polyester, or polyvinyl alcohol.

[0051] The second sealant layer 13 may contain a biomass-derived resin. For example, when the second sealant layer 13 contains polyethylene, the polyethylene may contain a biomass-derived component. When the second sealant layer 13 contains a biomass-derived resin, the amount of fossil fuel used can be reduced, and the environmental impact of the tube container packaging material 10 can be reduced.

[0052] The material for the second sealant layer 13 may be a material to which, for example, an antiblocking agent, a lubricant (fatty acid amide, etc.), a flame retardant, an inorganic or organic filler, etc. are optionally added.

[0053] In the present embodiment, the thickness of the second sealant layer 13 is preferably not less than 50 μm and not more than 250 μm.

[0054] <<Base material layer>> The base layer 14 is a layer for supporting, for example, the first sealant layer 11 and the second sealant layer 13, and for increasing the strength of the entire packaging material 10 for tube containers. The base layer 14 may be made of a film made from the above-mentioned resin pellets 1, similar to the first sealant layer 11. In addition, as the base layer 14, in addition to a film made from the resin pellets 1, a resin film constituting a normal packaging material may be appropriately used. As a material constituting the base layer 14, for example, a polyester-based resin, a polyamide-based resin, a polyaramid-based resin, a polyolefin-based resin, a polycarbonate-based resin, a polyacetal-based resin, a fluorine-based resin, a film or sheet of other tough resin, and others may be used. As an example, the base layer 14 may contain polyethylene terephthalate. When the base layer 14 contains a polyester-based resin, the polyester-based resin may contain a biomass polyester. Biomass polyester refers to a polyester obtained from a raw material containing a monomer derived from biomass.

[0055] The resin film or sheet may be an unstretched film, or a uniaxially or biaxially stretched film, etc. Among these, in the present embodiment, a biaxially stretched polyester resin film is preferred because of its excellent printability.

[0056] In the present embodiment, the thickness of the base layer 14 is preferably not less than 10 μm and not more than 25 μm.

[0057] <<Barrier layer>> The barrier layer 15 is a layer for suppressing the permeation of oxygen gas, water vapor, etc. By providing the tube container packaging material 10 with the barrier layer 15, the permeation of oxygen gas, etc. can be suppressed, and weight loss and deterioration of the contents can be effectively suppressed.

[0058] The barrier layer 15 may be, for example, a vapor-deposited film of an inorganic substance or an inorganic oxide, or a layer made of a gas barrier resin such as an ethylene-vinyl alcohol copolymer, polyvinylidene chloride, polyvinyl alcohol, or MXD6, etc. The barrier layer 15 may also be formed by a combination of the above-mentioned vapor-deposited films or layers made of gas barrier resins.

[0059] In order to ensure the visibility of the contents, the barrier layer 15 is preferably transparent. In this case, a vapor deposition film of an inorganic oxide may be particularly preferably used as the barrier layer 15. The inorganic oxide forming the vapor deposition film may be an inorganic oxide that is transparent and has gas barrier properties against oxygen gas, water vapor, and the like. Examples of such inorganic oxides include oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide. Among these, aluminum oxide and silicon oxide may be particularly preferably used in terms of gas barrier properties and production efficiency.

[0060] <<adhesive layer>> The adhesive layers, such as the first adhesive layer 16a, the second adhesive layer 16b, and the third adhesive layer 16c, are layers for bonding the first sealant layer 11, the release layer 12, the second sealant layer 13, etc. to each other. The material constituting the adhesive layer can be appropriately selected depending on the resin constituting the layer to be bonded.

[0061] The adhesive layer may be, for example, an anchor coating agent such as an isocyanate (urethane), polyethyleneimine, polybutadiene, or organic titanium. The adhesive layer may be, for example, a polyurethane, polyacrylic, polyester, epoxy, polyvinyl acetate, cellulose, or other laminating adhesive.

[0062] As materials constituting the adhesive layer, for example, polyethylene, polypropylene, ethylene-vinyl alcohol, ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid copolymer, ionomer, maleic anhydride modified polyolefin resin, etc. can be suitably used.

[0063] In the present embodiment, the thickness of each adhesive layer is preferably not less than 3 μm and not more than 60 μm.

[0064] <<Print layer>> The printed layer 17 is a layer for enhancing the design of the tube container packaging material 10 and the like. The printed layer 17 is a layer on which a picture such as a predetermined character, figure, pattern, or color coding is formed by ink. A known ink may be used. For example, the ink may contain at least one of an organic pigment and an inorganic pigment, and a binder resin, and may further contain various additives as necessary. The printed layer 17 can be formed, for example, on the base material layer 14 by a known printing method such as gravure printing, offset printing, letterpress printing, or screen printing.

[0065] <<Middle layer>> The intermediate layer 18 is a layer for increasing the strength of the entire tube container packaging material 10. The intermediate layer 18 is preferably made of a material having impact resistance and pinhole resistance. For example, a polyamide resin film such as a biaxially oriented nylon film may be used as the intermediate layer 18. The thickness of the intermediate layer 18 may be appropriately determined depending on the use and function of the tube container packaging material 10. The thickness of the intermediate layer 18 may be, for example, about 15 μm or more and 25 μm or less.

[0066] In such a tube container packaging material 10, the first sealant layer 11, the peeling layer 12, the second sealant layer 13, etc. may be laminated to each other by, for example, a wet lamination method, a dry lamination method, a solventless dry lamination method, an extrusion lamination method, a co-extrusion lamination method, an inflation method, or any other method. In addition, when carrying out the above-mentioned lamination, the films constituting each layer may be subjected to a pretreatment such as a corona treatment or an ozone treatment.

[0067] Furthermore, the recycled resin content in the tube container packaging material 10 may be 20% by weight or more and 80% by weight or less. When the recycled resin content is 20% by weight or more, the environmental impact of the tube container packaging material 10 can be effectively reduced. When the recycled resin content is 80% by weight or less, the hygiene of the tube container 40 produced from the tube container packaging material 10 can be improved.

[0068] Next, a tube container 40 including the tube container packaging material 10 according to this embodiment will be described.

[0069] As shown in Fig. 4, the tube container 40 includes a body tube 41, which is a laminated molded tube, and a head member 43 joined to one end 42 of the body tube 41. The body tube 41 has a generally cylindrical shape. The body tube 41 includes a tube container packaging material 10. In this case, the body tube 41 may be configured such that an outer surface 101 of the tube container packaging material 10 faces away from the contents, and an inner surface 102 faces the contents.

[0070] The body tube 41 has a body seal portion 44 formed by joining together the tube container packaging material 10. This body seal portion 44 is formed along the longitudinal direction of the body tube 41. Such a body tube 41 may be obtained, for example, by rolling the tube container packaging material 10 into a cylindrical shape, overlapping opposing ends, and joining them together, for example, by heat sealing.

[0071] The body tube 41 also has a bottom seal portion 45 where the tube container packaging materials 10 are joined together. The bottom seal portion 45 is a portion where the tube container packaging materials 10 are joined together near an opening (not shown) formed at the other end 46 of the body tube 41 after an appropriate amount of content C is filled into the tube container packaging materials 10.

[0072] The head member 43 has a shoulder portion 47 and a mouth portion 48. A cap 49 is attached to the mouth portion 48. The head member 43 is molded by, for example, compression molding. The head member 43 is made of, for example, a resin material such as high density polyethylene (HDPE).

[0073] Next, the operation of this embodiment having the above-mentioned configuration, that is, the method for recycling the resin body and the method for producing the resin pellets 1 will be described.

[0074] First, the resin body is collected (collection step, reference symbol S1 in FIG. 5). At this time, the resin body may be a resin product (tube container 40) that has been used on the market, or may be a material (packaging material 10 for tube containers or tube container 40) generated in a resin product manufacturing process before it is released to the market. The resin body may be another packaging material 10 for tube containers or tube container 40 made from resin pellets 1.

[0075] Next, the collected resin body (the tube container packaging material 10 or the tube container 40) is crushed (crushing step, reference symbol S2 in FIG. 5). The resin body may be crushed using, for example, a crusher (shredder), a crushing mill (hammer mill), or a grinder (grinder). The resin body may also be crushed into pieces of, for example, about 10 mm x 10 mm in size.

[0076] Next, the crushed resin body is stirred in water to dissolve the peeling layer 12, thereby separating the first sealant layer 11 from the second sealant layer 13, and removing foreign matter from the first sealant layer 11 (separation and foreign matter removal step, reference symbol S3 in FIG. 5). As described above, the peeling layer 12 is made of a material that dissolves in water. Therefore, the peeling layer 12 is dissolved by stirring the resin body in water. As a result, the first sealant layer 11 and the second sealant layer 13 are separated from each other. Furthermore, the crushed resin body is stirred in water to remove foreign matter from the first sealant layer 11. As a result, resin flakes from which dirt and foreign matter attached to the resin body have been removed are obtained. Furthermore, in the foreign matter removal step, foreign matter may be removed and the resin body may be washed using a washing liquid containing a sodium hydroxide aqueous solution or other surfactant. Note that, if necessary, a decontamination step for removing contaminants may be performed. In the separation and foreign matter removal step, for example, the temperature of the water in the stirrer may be 20°C or higher and 70°C or lower. The stirring speed may be 150 rpm or more and 250 rpm or less, and the stirring time may be 30 minutes or more and 60 minutes or less.

[0077] Next, the first sealant layer 11 separated from the second sealant layer 13 is dried and sorted (drying and sorting step, reference symbol S4 in FIG. 5). At this time, the first sealant layer 11 may be sorted by various sorting methods such as a specific gravity sorting method, a wind sorting method, or an electrostatic sorting method. In the drying and sorting step, the drying temperature may be 20° C. or more and 50° C. or less. The drying time may be 30 minutes or more and 180 minutes or less.

[0078] Next, the selected first sealant layer 11 is pulverized (pulverization step, reference symbol S5 in FIG. 5). The first sealant layer 11 may be pulverized using, for example, a pulverizer (shredder), a pulverizing mill (hammer mill), or a grinder. The first sealant layer 11 may be pulverized to a size of, for example, about 5 mm x 5 mm.

[0079] Next, the pulverized first sealant layer 11 is melted (melting step, reference symbol S6 in FIG. 5). The first sealant layer 11 is melted, for example, in a pellet producing device (not shown). In the melting step, the melting temperature may be 170° C. or more and 200° C. or less.

[0080] Next, the resin pellets 1 are formed from the molten first sealant layer 11 (molding step, reference symbol S7 in FIG. 5). At this time, the molten first sealant layer 11 is first extruded in a string-like shape from a filter in a pellet producing device (not shown). Then, the extruded first sealant layer 11 (strand) is cut into granular shapes. In this way, the resin pellets 1 are formed.

[0081] Thereafter, the resin pellets are cooled (cooling step, reference numeral S8 in FIG. 5).

[0082] In this manner, the tube container 40 and the like are recycled, and the resin pellets 1 containing the recycled resin are obtained.

[0083] Next, a method for producing the tube container packaging material 10 will be described.

[0084] For example, when producing a tube container packaging material 10 shown in Fig. 2, first, a first sealant layer 11 is prepared. At this time, for example, a resin pellet 1 produced by the method shown in Fig. 5 is used as the first sealant layer 11, and a film may be produced by, for example, an inflation method.

[0085] A base layer 14 is also prepared. For example, a polyethylene terephthalate film or the like may be used as the base layer 14. Next, a coating agent, for example, a vinyl alcohol resin to which a crosslinking agent has been added, is applied to the outer surface of the polyethylene terephthalate film as the release layer 12. The release layer 12 may be formed by various printing and coating methods, for example, gravure printing, letterpress printing, flexographic printing, offset printing, or silk screen printing. A printing layer is also formed on the inner surface of the polyethylene terephthalate film.

[0086] Also, a barrier layer 15 is prepared. As the barrier layer 15, for example, an aluminum foil or the like may be used.

[0087] Furthermore, the second sealant layer 13 is prepared. As the second sealant layer 13, for example, a polyethylene film or the like may be used.

[0088] Next, the first sealant layer 11, the base layer 14, the barrier layer 15 and the second sealant layer 13 are laminated together by a dry lamination method, etc. In this manner, the tube container packaging material 10 shown in FIG.

[0089] As described above, according to the present embodiment, the tube container packaging material 10 includes the first sealant layer 11, the peeling layer 12, and the second sealant layer 13, which are arranged in this order from the outer surface 101 to the inner surface 102. At least 90% of the first sealant layer 11 is made of the same resin material. This allows the quality of the resin pellets 1 produced from the first sealant layer 11 of the tube container packaging material 10 to be stabilized. Furthermore, the peeling layer 12 is made of a material that dissolves in water. This allows the first sealant layer 11 to be easily separated from the second sealant layer 13 by stirring the tube container packaging material 10 in water. Therefore, the first sealant layer 11 of the tube container packaging material 10 can be easily recycled. As a result, the environmental impact of the tube container packaging material 10 can be reduced. In particular, the first sealant layer 11 can be separated from the second sealant layer 13 by melting the peeling layer 12. For this reason, even if a layer (e.g., base layer 14 or barrier layer 15) made of a material different from the material constituting the first sealant layer 11 is provided between the peel layer 12 and the second sealant layer 13, only the first sealant layer 11 can be easily recycled.

[0090] Moreover, according to the present embodiment, the tube container packaging material 10 further includes a base material layer 14 provided between the peeling layer 12 and the second sealant layer 13. This can increase the strength of the entire tube container packaging material 10.

[0091] Moreover, according to this embodiment, the packaging material 10 for tube containers further includes a barrier layer 15 provided between the peeling layer 12 and the second sealant layer 13. This makes it possible to suppress the permeation of oxygen gas and the like in the tube container 40 produced from the packaging material 10 for tube containers, and effectively suppress weight loss and deterioration of the contents.

[0092] Furthermore, according to this embodiment, at least one of the first sealant layer 11 and the second sealant layer 13 contains a biomass-derived resin. In the tube container 40 produced from the tube container packaging material 10, the amount of fossil fuel used can be reduced. Therefore, the environmental impact of the tube container 40 can be reduced.

[0093] Further, according to the present embodiment, the method for producing the resin pellets 1 includes a step of recovering the tube container packaging material 10 and the like, a step of crushing the recovered tube container packaging material 10 and the like, a step of stirring the crushed tube container packaging material 10 and the like in water to dissolve the peeling layer 12 and thereby separate the first sealant layer 11 from the second sealant layer 13 and remove foreign matter from the first sealant layer 11, a step of drying and selecting the first sealant layer 11 separated from the second sealant layer 13, a step of crushing the selected first sealant layer 11, a step of melting the crushed first sealant layer 11, a step of forming the resin pellets 1 from the melted first sealant layer 11, and a step of cooling the resin pellets 1. As a result, the resin pellets 1 contain recycled resin, and the environmental impact of the product (e.g., tube container 40) produced from the resin pellets 1 can be reduced. Moreover, at least 90% or more of the first sealant layer 11 for producing the resin pellets 1 is made of the same resin material. This makes it possible to stabilize the quality of products produced from the resin pellets 1. Furthermore, since at least 90% or more of the first sealant layer 11 is made of the same resin material, it makes it easier to recycle products produced from the resin pellets 1. EXAMPLES

[0094] Next, a specific example of the above embodiment will be described.

[0095] (Example) A resin film (thickness: 180 μm) containing linear low-density polyethylene as a main component was prepared as the first sealant layer. The content of linear low-density polyethylene in the first sealant layer was 95%.

[0096] A polyethylene terephthalate film (thickness 12 μm) was prepared as a base layer. Next, a coating agent made of a vinyl alcohol resin with a crosslinking agent added thereto was applied to the outer surface of the polyethylene terephthalate film as a release layer. A print layer was also formed on the inner surface of the polyethylene terephthalate film.

[0097] In addition, as an intermediate layer, a polyethylene terephthalate film (thickness 12 μm) on which an aluminum vapor deposition film (barrier layer) was formed was prepared.

[0098] Furthermore, as a second sealant layer, a resin film (thickness: 80 μm) made of virgin resin of linear low-density polyethylene was prepared.

[0099] Next, the first sealant layer, the base layer, the intermediate layer and the second sealant layer were laminated together by dry lamination. The layer structure of the obtained packaging material for tube containers is as follows. LLDPE / adhesive layer / peeling layer / PET / print / adhesive layer / vapor deposition film / PET / adhesive layer / LLDPE In the above, "LLDPE" means a resin film containing linear low density polyethylene as the main component or a resin film made of virgin resin of linear low density polyethylene (hereinafter the same), and "PET" means a polyethylene terephthalate film (hereinafter the same).

[0100] Next, a tube container as shown in Fig. 4 was produced from the obtained laminate. At this time, high density polyethylene (HDPE) was used as the material for the head member.

[0101] (Comparative Example) The thickness of the first sealant layer was 130 μm, no peeling layer was provided, and the second sealant layer was made of low-density polyethylene (density 0.92 g / cm 3 A packaging material for tube containers was produced in the same manner as in Example, except that a resin film (thickness: 180 μm) made of virgin resin of 1,2-dichloro-1,3 ... The layer structure of the obtained packaging material for tube containers is as follows. LLDPE / adhesive layer / PET / print / adhesive layer / vapor deposition film / PET / adhesive layer / LDPE

[0102] Next, a tube container as shown in Fig. 4 was produced from the obtained laminate. At this time, high density polyethylene (HDPE) was used as the material for the head member.

[0103] (1) Recyclability evaluation Next, recyclability was evaluated. At this time, resin pellets were produced from each of the tube containers according to the embodiment and the comparative example by the method shown in Fig. 5. At this time, in the separation and foreign matter removal process, the temperature of the water in the mixer (general-purpose mixer, BL1200, manufactured by Shinto Scientific Co., Ltd.) was 50°C, the mixing speed was 200 rpm, and the mixing time was 30 minutes. In addition, in the drying and sorting process, the drying temperature was 50°C, and the drying time was 180 minutes. Furthermore, in the melting process, the melting temperature was 190°C.

[0104] (2) Quality evaluation Next, the quality of the prepared resin pellets was evaluated by evaluating the melt flow rate (MFR), Charpy impact strength, tensile yield strength, flexural modulus, and odor of the resin pellets.

[0105] The melt flow rate (MFR) of the resin pellets was measured by Method A (mass measurement method) in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 21.2N.

[0106] The Charpy impact strength of the resin pellets was measured using a Charpy impact tester (manufactured by Toyo Seiki Co., Ltd.) in accordance with JIS K7111-1:2012. Specifically, first, a dumbbell-shaped test piece with a notch was prepared from each of the resin pellets prepared from the tube containers according to the examples and the comparative examples. Next, the test piece was placed in the Charpy impact tester by supporting both ends of the test piece. Next, the test piece was destroyed by striking the test piece with a hammer from the opposite side of the notch. Then, the impact strength at which the test piece was destroyed was measured as the Charpy impact strength.

[0107] The tensile yield strength of the resin pellets was measured using a tensile tester (manufactured by Toyo Seiki Co., Ltd., product name "Universal Testing Machine / Tensile Tester "Strograph VG"") in accordance with JIS K7161-1:2014. Specifically, first, dumbbell-shaped test pieces were prepared from the resin pellets prepared from the tube containers according to the examples and comparative examples. Next, the test pieces were placed in the tensile tester by chucking the vicinity of both ends in the longitudinal direction of the test pieces with the gripping members of the tensile tester. Next, the test pieces were pulled by moving the gripping members in the direction away from each other at a test speed of 300 mm / min. The strength at which the test pieces broke was measured as the tensile yield strength.

[0108] The flexural modulus of the resin pellets was measured using a three-point bending tester (Shimadzu Corporation, fully automatic plastic tensile / bending tester) in accordance with JIS K7161-1:2014. Specifically, first, dumbbell-shaped test pieces were prepared from the resin pellets prepared from the tube containers according to the examples and comparative examples, and the test pieces were placed in the three-point bending tester. Next, the test pieces were deformed by applying pressure to the approximate center of the longitudinal direction of the test pieces. At this time, the load was applied so as to be gradually increased from 0 N to 120 N. Then, the flexural modulus was calculated from the stress and strain amount when the test pieces were deformed.

[0109] The above results are shown in Tables 1 and 2.

[0110] [Table 1]

[0111] [Table 2]

[0112] In the "Separability" column in Table 1, "good" means that the first sealant layer and the second sealant layer were easily separated, and "bad" means that the first sealant layer and the second sealant layer could not be separated.

[0113] In the "Moldability" column in Table 1, "good" means that the filter of the pelletizer was not clogged and the strands extruded in the pelletizer had a clean appearance, while "bad" means that the resin clogged the filter and resin pellets (strands) could not be formed.

[0114] In the "Appearance" column of Table 1, "good" means that the appearance of the resin pellet was smooth and no undissolved resin (so-called fish eyes) was visually observed, while "bad" means that undissolved resin (fish eyes) was visually observed.

[0115] In the "MFR" column in Table 2, "good" means that the melt flow rate was greater than 0.3 g / 10 min and less than 100 g / 10 min, and "bad" means that the melt flow rate was less than 0.3 g / 10 min.

[0116] In the "Charpy impact strength" column of Table 2, "good" means that the Charpy impact strength is 2.5 kJ / m 2 "Bad" means that the Charpy impact strength was 2.5 kJ / m or more. 2 This means that it was less than

[0117] In the "tensile yield strength" column in Table 2, "good" means that the tensile yield strength was 5.0 MPa or more and less than 25.0 MPa, and "bad" means that the tensile yield strength was less than 5.0 MPa.

[0118] In the "flexural modulus" column in Table 2, "good" means that the flexural modulus was 100 MPa or more and less than 900 MPa, and "bad" means that the flexural modulus was 900 MPa or more.

[0119] In the "Odor" column in Table 2, "good" means that almost no residual odor was detected in the sensory evaluation, and "bad" means that a residual odor was detected in the sensory evaluation.

[0120] As a result, as shown in Tables 1 and 2, the tube container packaging material according to the embodiment achieved good results in all items. That is, the tube container packaging material according to the present embodiment was able to maintain high quality of the recycled resin when the resin was recycled. Therefore, it was found that the present embodiment can reduce the environmental load.

[0121] It is also possible to combine the multiple components disclosed in the above embodiments as necessary, or to delete some of the components disclosed in the above embodiments. [Explanation of symbols]

[0122] 1 Resin pellets 10. Packaging materials for tube containers 11 First sealant layer 12 Release layer 13 Second sealant layer 14 Base material layer 15 Barrier Layer 40 Tube Container 41 Body tube 42 one end 43 Head parts 101 Exterior 102 Inside

Claims

1. The sealant layer includes a first sealant layer, a release layer, and a second sealant layer, which are arranged in this order from the outer surface to the inner surface, At least 90% of the first sealant layer is made of the same resin-based material, The packaging material for tube containers, wherein the release layer is made of a material that dissolves in water.

2. The packaging material for tube containers according to claim 1 , wherein the second sealant layer contains a material of the same resin system.

3. The packaging material for tube containers according to claim 1 , further comprising a base material layer provided between the release layer and the second sealant layer.

4. The packaging material for tube containers according to claim 1 , further comprising a barrier layer provided between the release layer and the second sealant layer.

5. The packaging material for tube containers according to claim 1 , wherein at least one of the first sealant layer and the second sealant layer contains a resin derived from biomass.

6. In a tube container, A body tube having the packaging material for a tube container according to any one of claims 1 to 5; a head member joined to one end of the body tube.

7. A method for producing resin pellets, comprising the steps of: A step of recovering the packaging material for tube containers according to any one of claims 1 to 5 or the tube container according to claim 6; A step of crushing the collected tube container packaging material or the tube container; a step of agitating the crushed tube container packaging material or the crushed tube container in water to dissolve the release layer, thereby separating the first sealant layer from the second sealant layer and removing foreign matter from the first sealant layer; drying and screening the first sealant layer separated from the second sealant layer; pulverizing the selected first sealant layer; Melting the pulverized first sealant layer; forming a resin pellet from the molten first sealant layer; and cooling the resin pellets.

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