JP2018058596A - Laminated body for heat insulation container, heat insulation container, manufacturing method of laminated body for heat insulation container, and manufacturing method of heat insulation container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated body for a heat insulation container provided with a printing layer on its surface, which can deal with small lot and multi-product, has no fear of environmental pollution and can suppress the occurrence of so-called migration.SOLUTION: In the laminate body for a heat insulation container having, at least, a printing layer, a cover layer, a base material layer composed of paper, a steam barrier layer for blocking steam generated from the paper constituting the base material layer in sequence from the outer surface side, the cover layer is made of a foamable thermoplastic resin, and a binder is contained in the printing layer, and an urethane structure polymer and either of both of a photopolymerization initiator and by-products of the photopolymerization initiator are contained in the binder. Here, the ratio of the urethane structure polymer to the total mass of the printing layer is 15 mass% or more and 90 mass% or less.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a laminated body for a heat insulating container, a heat insulating container, a method for producing a laminated body for a heat container, and a method for producing a heat insulating container.

  Conventionally, a laminated body for a heat insulating container in which a foam layer is provided on one surface of a base material made of paper and a non-foam layer is provided on the other surface is known. For example, Patent Document 1 discloses a heat insulating container having a layer structure of foamed low density polyethylene (LDPE) / paper / medium density polyethylene (MDPE) from the surface side.

JP-A-57-110439

  A general heat insulating container and a laminated body for a heat insulating container for molding the heat insulating container including the heat insulating container disclosed in Patent Document 1 are resins for foaming on the surface of paper serving as a base material (in Patent Document 1). Is a low-density polyethylene), and another resin (medium-density polyethylene in Patent Document 1) is also provided on the back side to form a laminated body for a heat insulating container. By heating this, moisture contained in the paper is evaporated. The surface side resin (low density polyethylene in Patent Document 1) is foamed by this water vapor, so-called water vapor foaming.

  In such a laminate for a heat insulating container, a printing layer for imparting designability may be provided on the resin on the surface side, but for offset printing that can handle small lots and multiple items. The ionization curable ink used generally has a high film strength and a high crosslink density, making it difficult to form a foamed layer. Therefore, the printing layer is generally formed by gravure printing using a rotary press, and is not suitable for small lots and many items. In addition, because so-called solvent-based inks are used for gravure printing, environmental problems due to volatile components (solvents) and the migration of ink components to the product after printing may occur, making it unsuitable as a food container. There was also a case.

  The present invention has been made in such a situation, and is a laminated body for a heat insulating container provided with a printed layer on the surface, can be applied to small lots and many items, has no fear of environmental pollution, and The main object is to provide a laminated body for a heat insulating device capable of suppressing the occurrence of so-called migration, a heat insulating container using the laminated body, a method for producing a laminated body for a heat insulating container, and a method for producing a heat insulating container.

  In order to solve the above problems, the present invention provides, from the outer surface side, a printing layer, a cover layer, a base material layer composed of paper, and a water vapor shielding layer that intercepts water vapor generated from the paper constituting the base material layer. A laminate for a heat insulating container having at least the cover layer is made of a foamable thermoplastic resin, the printing layer includes a binder, and the binder includes a urethane structure polymer and photopolymerization. One or both of an initiator and a by-product of a photopolymerization initiator, and the ratio of the urethane structure polymer to the total mass of the printing layer is 15% by mass or more and 90% by mass or less. It is characterized by.

  In the above invention, the binder contains a by-product of a photopolymerization initiator, and the proportion thereof is 0.2% by mass or more and 1.5% by mass or less with respect to the total mass of the printing layer. There may be.

  In the above invention, the foamable thermoplastic resin may be any one of a high-pressure method low-density polyethylene, polypropylene, and an ethylene / α-olefin copolymer.

  In the above invention, a surface layer may be provided between the print layer and the cover layer.

  In the above invention, the cover layer may be foamed.

  Another invention of the present application for solving the above problems is a heat insulating container, wherein at least a part thereof is constituted by the laminate for a heat insulating container of the present invention.

  In said invention, it has a trunk | drum and a bottom part, and the said trunk | drum may be comprised with the laminated body for heat insulation containers of the said this invention.

  Yet another invention of the present application for solving the above-mentioned problems is a water vapor barrier that shuts off water vapor generated from a printed layer, a cover layer, a base material layer made of paper, and paper forming the base material layer from the outer surface side. A step of preparing a prepared body having at least the cover layer, the base material layer, and the water vapor blocking layer, and a cover layer in the prepared body The method includes a printing step of printing using an ionizing curable ink, and an irradiation step of irradiating the ionizing radiation ink printed on the cover layer with an ionizing radiation to form a printed layer.

  Further, another invention for solving the above-mentioned problems is that, from the outer surface side, a printed layer, a surface layer, a cover layer, a substrate layer composed of paper, and water vapor generated from the paper constituting the substrate layer. A method for producing a laminate for a heat insulating container having at least a water vapor barrier layer for blocking, the step of preparing a preparation having at least the surface layer, the cover layer, the base material layer, and the water vapor barrier layer; A printing step of printing using an ionizing curable ink on the surface layer in the preparation; an irradiation step of irradiating ionizing radiation to the ionizing curable ink printed on the surface layer to form a printed layer; It is characterized by including.

  Still another invention for solving the above problems is a method for manufacturing a heat insulating container, the step of preparing a heat insulating container laminate manufactured by the method for manufacturing a heat insulating container laminate, and the heat insulation. A punching process for punching the laminated body for containers into a predetermined shape, a molding process for molding the punched laminated body for insulated containers into a container shape, and heating and covering the laminated body for insulated containers molded into the container shape And a heating step for foaming the layer.

  Still another invention for solving the above problems is a method for manufacturing a heat insulating container, the step of preparing a heat insulating container laminate manufactured by the method for manufacturing a heat insulating container laminate, and the heat insulation. A punching process for punching a container laminate into a predetermined shape, a heating process for heating the punched laminate for a thermal insulation container to foam a cover layer, and a laminate for a thermal insulation container in a state where the cover layer is foamed And a molding step of molding the container into a container shape.

  Still another invention for solving the above problems is a method for manufacturing a heat insulating container, the step of preparing a heat insulating container laminate manufactured by the method for manufacturing a heat insulating container laminate, and the heat insulation. A heating step of heating the container laminate to foam the cover layer; a punching step of punching out the insulating container laminate in a state where the cover layer is foamed; and the punched insulating container laminate. And a molding step of molding into a container shape.

  According to the laminate for a heat insulating container of the present invention, the binder of the printing layer contains the urethane structure polymer and the photopolymerization initiator by-product in a predetermined ratio, that is, the printing layer is ionized. Since it is formed of a curable ink, it is possible to form this printed layer by a printing method that can use an ionizing curable ink such as offset printing, flexographic printing, inkjet printing, or screen printing. Therefore, it is possible to meet the demand for small lots and many items, the amount of solvent used can be reduced compared to solvent-based inks, and the occurrence of so-called migration can also be suppressed.

  Moreover, even if it exists in the heat insulation container of this invention, since it shape | molds using the laminated body for heat insulation containers of the said this invention, there exists an effect similar to the above.

  In addition, the same effects as described above can be achieved even in the method for manufacturing a laminate for a heat insulating container of the present invention and the method for manufacturing a heat insulating container of the present invention.

It is sectional drawing of the laminated body for heat insulation containers of the state which the cover layer concerning embodiment of this invention does not foam. It is sectional drawing of the laminated body for heat insulation containers of the state which the cover layer concerning the embodiment of this invention foamed.

  Hereinafter, the laminated body for heat insulation containers and the heat insulation container concerning embodiment of this invention are demonstrated in detail using drawing.

  FIG. 1 is a cross-sectional view of a laminate for a heat insulating container in a state where a cover layer is not foamed according to an embodiment of the present invention.

  FIG. 2 is a cross-sectional view of a laminate for a heat insulating container in a state where a cover layer is foamed according to an embodiment of the present invention.

  As shown in FIG. 1, the laminated body 10A for a heat insulating container according to this embodiment includes a base layer 12 composed of a printed layer 15, a surface layer 16, a cover layer 11A, and paper in this order from the outer surface side. At least a water vapor barrier layer 13 that blocks water vapor generated from the paper constituting the base material layer 12 is provided on the surface of the base material layer 12 on the side where the cover layer 11A is not laminated. It is configured by being laminated. The surface layer 16 is not an essential layer but a layer that can be arbitrarily formed.

  And as shown in FIG. 2, the low density which comprises a cover layer with the water vapor | steam which generate | occur | produces from the paper which comprises the base material layer 12 by heating 10A of laminated bodies for heat insulation containers concerning this embodiment shown in FIG. Polyethylene is in a foamed state.

  In the present specification, both the state where the cover layer (11A) is not foamed and the state where the cover layer (11) is foamed are expressed as a laminate for a heat insulating container (10A, 10). To do. Moreover, when forming a heat insulation container using the laminated body for heat insulation containers, the side located outside the heat insulation container is referred to as an “outer surface side”, and the side located inside the heat insulation container is referred to as an “inner surface side”. In FIG. 1 and FIG. 2, the upper side is the “outer surface side” and the lower side is the “inner surface side”.

  Below, each layer which comprises laminated body 10A, 10 for heat insulation containers is demonstrated.

(Cover layer)
The cover layer 11A before foaming is made of a foamable thermoplastic resin. Examples of foamable thermoplastic resins include medium / low pressure ethylene homopolymers, high pressure low density polyethylene, polypropylene, ethylene / α-olefin copolymers, ethylene / vinyl acetate copolymers, ethylene / ethyl acrylate. A copolymer, an ethylene / acrylic acid copolymer, an ethylene / methacrylic acid copolymer, etc. can be mentioned, and even in other cases, a desired foamed state can be formed by water vapor generated from a base material layer described later Can be appropriately selected and used. Among these, it is preferable to use high-pressure method low-density polyethylene from the viewpoint of improving the expansion ratio. In the following description, the cover layer 11A (11) is used to clearly distinguish the high-pressure low-density polyethylene constituting the cover layer 11A (11) and the polyethylene resin constituting the surface layer 16 described later. The high-pressure method low-density polyethylene constituting is represented as “high-pressure method low-density polyethylene (B)”, and the polyethylene-based resin constituting the surface layer 16 is represented as “polyethylene-based resin (A)”.

  The high pressure method low density polyethylene (B) constituting the cover layer 11A in the present embodiment can be obtained by a conventionally known high pressure method radical polymerization method.

  The melt mass flow rate (hereinafter simply referred to as “MFR”) measured by JIS K6922-1 (1997) of the high pressure method low density polyethylene (B) is 4 to 100 g / 10 min. Is preferable, more preferably 10 to 30 g / 10 minutes, and still more preferably 10 to 25 g / 10 minutes.

Further, the density (hereinafter simply referred to as “density”) measured by JIS K6922-1 (1997) of the high-pressure method low-density polyethylene (B) is 870 to 935 kg / m ³ because of excellent foamability. More preferably, it is 890-935 kg / m < ³ >, More preferably, it is the range of 900-925 kg / m < ³ >.

  For the high-pressure low-density polyethylene (B) constituting the cover layer 11A in this embodiment, an antioxidant, a light stabilizer, an antistatic agent, a lubricant, an antiblocking agent, etc. are generally used for polyolefin resins as necessary. The additives that have been used may be added within a range that does not impair the object of the present invention.

  Furthermore, other polyolefins may be mixed with the high pressure method low density polyethylene (B). At this time, since the foamability is excellent, the mixing ratio is preferably 50 to 99% by weight for the high pressure method low density polyethylene (B) and 1 to 50% by weight for the other polyolefins.

Examples of the polyolefin to be mixed with the high-pressure method low-density polyethylene (B) include ethylene / α-olefin copolymers, polypropylene, polybutene, and the like, and since it has excellent foamability, the density is 850 kg / m ³ or more and 920 kg / m. An ethylene / α-olefin copolymer (B) of less than ³ is preferred.

  Examples of the α-olefin used in the ethylene / α-olefin copolymer (B) include propylene, 1-butene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-pentene, 1-pentene, Examples include hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, and the like, and one or more of these are used.

  Furthermore, the method for obtaining the ethylene / α-olefin copolymer (B) is not particularly limited, and examples thereof include a high / medium / low pressure ion polymerization method using a Ziegler-Natta catalyst, a Philips catalyst, or a metallocene catalyst. Such a copolymer can be conveniently selected from commercially available products.

  When the polyolefin is mixed with the high-pressure method low-density polyethylene (B) constituting the cover layer 11A in the present embodiment, the pellets are a mixture of pellets of the high-pressure method low-density polyethylene (B) and the polyolefin pellets in a solid state. However, a mixture obtained by melt-kneading with a single screw extruder, a twin screw extruder, a kneader, a Banbury or the like is preferable because a product with stable quality can be obtained. When using a melt-kneading apparatus, the melting temperature is preferably about the melting point of polyethylene resin to about 300 ° C.

Furthermore, in this embodiment, the loss elastic modulus G calculated | required by measuring dynamic viscoelasticity using the cone-disk rheometer in 190 degreeC of the polyethylene-type resin (A) which comprises the surface layer 16 mentioned later. The storage elastic modulus G ′ _a (500) at an angular velocity ω (s ⁻¹ ) where (Pa) is 500 Pa is G ′ of the high-pressure low-density polyethylene (B) used for the cover layer 11A obtained by the same method. It is preferable that it is smaller than _b (500) because stable extrusion molding is possible and an excellent foam appearance is obtained, and an excellent foam appearance is obtained when G ′ _b (500) is 95 Pa or less. preferable.

  The thickness of the cover layer 11A before foaming is not particularly limited, but is preferably 10 to 150 μm and more preferably 30 to 100 μm, and more preferably 30 to 30 μm from the viewpoint of economy, and further excellent heat insulation. 80 μm.

  The cover layer 11A before foaming shown in FIG. 1 is formed on the base material layer 12 as described above, and is heated by the water vapor generated from the paper constituting the base material layer 12 as shown in FIG. The cover layer 11 is in the foamed state.

  The heating temperature at this time is not particularly limited as long as it is not lower than the melting point of the low-density polyethylene as the material and the laminated body 10 for a heat insulating container is not altered, but is usually 100 to 200 ° C., preferably 110 to It is 160 degreeC, More preferably, it is 110-125 degreeC. The heating time is not particularly limited, but is usually about 10 seconds to 10 minutes. The heating method is not particularly limited, and heating can be performed by a conventionally known method. Examples include heating with hot air, infrared rays, far infrared rays, microwaves, high frequencies, and the like.

  The thickness of the cover layer 11 after foaming is also not particularly limited, but is preferably 20 to 1200 μm, more preferably 300 to 900 μm, and still more preferably 400 to 800 μm because of excellent heat insulation and foam appearance.

(Surface layer)
In the heat insulating container laminates 10A and 10 according to the present embodiment, the surface layer 16 is provided on the cover layers 11A and 11, but this is an arbitrary layer and is not necessarily provided. . By providing the surface layer 16, it is possible to flatten a portion (surface) on which a printing layer to be described later is formed, and to improve the design.

  The material of the surface layer 16 is not particularly limited, and can be appropriately selected from materials that can achieve the above-described effects. In particular, the measurement is based on JIS K6922-2 (2010). It is preferable to use a polyethylene resin (A) whose melting point is higher than the melting point of the high-pressure method low-density polyethylene (B) constituting the cover layers 11A and 11. By providing the surface layer 16 made of such a material, the cover layer 11A can be uniformly foamed without being affected by the printing layer 15 described later.

  The polyethylene resin (A) constituting the surface layer 16 includes medium / low pressure ethylene homopolymer, high pressure low density polyethylene, polypropylene, ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer, ethylene -Ethyl acrylate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, etc., but ethylene / α-olefin copolymer (A), medium / low pressure ethylene homopolymer ( A) is particularly preferable because the foaming ratio of the cover layer 11A can be improved and the laminate appearance is excellent.

  Examples of the α-olefin used in the ethylene / α-olefin copolymer (A) include propylene, 1-butene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-pentene, 1-hexene, 1 -Heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene and the like can be mentioned, and one or more of these can be used.

  The method for obtaining such an ethylene / α-olefin copolymer (A) is not particularly limited, and a high / medium / low pressure ion polymerization method using a Ziegler-Natta catalyst, a Phillips catalyst, or a metallocene catalyst is used. It can be illustrated. Such a copolymer can be conveniently selected from commercially available products, but since the laminate has an excellent appearance, an ethylene / α-olefin copolymer obtained by a polymerization method using a Ziegler-Natta catalyst is used. Particularly preferred.

  The medium / low pressure ethylene homopolymer (A) can be obtained by a conventionally known medium / low pressure ion polymerization method.

  When the MFR of the polyethylene resin (A) constituting the surface layer 16 in the present embodiment is in the range of 0.1 to 100 g / 10 minutes, more preferably in the range of 3 to 50 g / 10 minutes, when the laminate is molded. Processing becomes easy.

  The ethylene / α-olefin copolymer (A) and the medium / low pressure ethylene homopolymer (A) constituting the surface layer 16 are blended with other polyolefins such as high pressure low density polyethylene and polypropylene. The blending ratio of these other polyolefins is preferably 1 to 30% by weight from the viewpoint of laminate moldability and laminate appearance.

  Furthermore, the polyethylene resin (A) constituting the surface layer 16 may be added to polyolefin resins such as an antioxidant, a light stabilizer, an antistatic agent, a lubricant, an antiblocking agent, etc. An agent may be added as long as the object of the present invention is not impaired.

  The thickness of the surface layer 16 is not particularly limited, but is preferably 1 to 20 μm, and more preferably 4 to 12 μm because of excellent appearance.

  Further, the ratio of the thickness of the surface layer 16 and the cover layer 11A before foaming is preferably 1: 2 to 1:30 because of excellent balance between heat insulation and foam appearance, more preferably 1: 4 to 1: 1. 12, more preferably 1: 6 to 1:10.

  The ratio of the thickness of the surface layer 16 to the thickness of the cover layer 11 after foaming is preferably 1:15 to 1: 360, since it is excellent in the balance between heat insulation and foam appearance, more preferably 1:45. It is 1: 240, More preferably, it is 1: 80-1: 150. In addition, the thickness of the cover layer 11 after foaming is preferably the above by using paper having a large basis weight or paper having a high water content as the base material layer 12 or by increasing the thickness of the cover layer 11A before foaming. It is possible to make the thickness more than the ratio, but even if it is thicker than this, the heat insulation and design will not be improved dramatically, and overspec when used for normal size heat insulation containers It is thought that it becomes.

(Print layer)
In the heat insulating container laminates 10A and 10 according to the embodiment of the present invention, the printing layer 15 is provided on the surface layer 16, and the printing layer 15 includes a binder. The urethane structure polymer and any one or both of a photopolymerization initiator and a photopolymerization initiator by-product, and the ratio of the urethane structure polymer to the total mass of the printed layer is 15 masses % Or more and 90% by mass or less. And it is especially preferable that the ratio of the by-product of the said photoinitiator with respect to the total mass of the said printing layer is 0.2 to 1.5 mass%. Since such a printing layer is formed of an ionization curable ink, the printing layer can be formed by a printing method that can use an ionization curable ink such as offset printing, flexographic printing, inkjet printing, or screen printing. Is possible. Therefore, it is possible to meet the demand for small lots and many items, the amount of solvent used can be reduced compared to solvent-based inks, and the occurrence of so-called migration can also be suppressed. Moreover, according to such a printing layer 15, what is called followability can be improved, and when the cover layer 11A is in a foamed state, the foam of the cover layer 11A can be followed well and surface smoothness can be ensured. And can exhibit excellent design properties. Such a print layer 15 does not necessarily have to be formed on the entire surface layer 16, and may be formed partially as shown in FIGS.

  Further, the print layer 15 is not necessarily a single layer, and as shown in FIGS. 1 and 2, a plurality of print layers (in FIG. 1 and FIG. 2, three print layers 15a, 15b, and 15c). In this case, all the printing layers (15a, 15b, and 15c) contain a binder, and the binder includes a urethane structure polymer and Any one or both of a photopolymerization initiator and a photopolymerization initiator by-product, and the ratio of the urethane structure polymer to the total mass of the printing layer is 15% by mass or more and 90% by mass or less. It is. And preferably, the ratio of the by-product of the said photoinitiator with respect to the total mass of the said printing layer is 0.2 to 1.5 mass%.

  Here, the “urethane structure polymer” referred to in the present specification is an acrylate structure obtained by polymerizing an acrylate containing a urethane structure, and has been conventionally used in the art. It is intended to use urethane in a broad sense including modified urethane such as urethane or urethane urea. Moreover, the urethane structure used in the present invention is not particularly limited by the production method thereof, and may be various urethane resins obtained by applying a known or well-known method relating to urethane.

  On the other hand, the “by-product of the photopolymerization initiator” referred to in the specification of the present application intends a material disproportionated with the recombination of the photopolymerization initiator. That is, the reaction of the photopolymerization initiator is generally about 90% to 97%, causing recombination and disproportionation in addition to the reaction, and this is intended in the present specification.

  Further, the printing layer 15 may contain a photopolymerization initiator in addition to the urethane structure polymer and the byproduct of the photopolymerization initiator. As photopolymerization initiators, acetophenone, benzophenone, α-hydroxyalkylphenone, Michler's ketone, benzoin, benzylmethyl ketal, benzoylbenzoate, α-acyloxime ester, thioxanthones, α-aminoalkylphenone, acylphosphine oxide, benzyldimethyl Ketal etc. are mentioned, These can be used individually or in mixture of 2 or more types.

  The binder component of the printing layer 15 is not limited to the urethane structure polymer, the by-product of the photopolymerization initiator, and the photopolymerization initiator, and various pigments may be used to realize a desired design. Additives such as wax, dye, and wax can be used freely.

  Examples of the binder component other than the urethane structure polymer include polyester acrylate, polyol acrylate, and epoxy acrylate. These can be used alone or in admixture of two or more.

  Furthermore, inorganic and organic pigments and dyes generally used in printing inks can be used as the colorant. Examples of inorganic pigments include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, aluminum hydroxide, chromium oxide, silica, carbon black, aluminum, mica (mica), and the like. On the other hand, examples of the organic pigment include soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments. The colorants can be used alone or in admixture of two or more for the purpose of adjusting the hue and density.

  In addition, in order to improve functionality as ink, print quality and various resistances, pigment dispersants, leveling agents, waxes, crosslinking agents, surfactants, antifoaming agents, plasticizers, titanium chelates, Additives such as light stabilizers, infrared absorbers, ultraviolet absorbers, fragrances, and flame retardants can also be included.

  The method for forming the printing layer 15 is not particularly limited, but it is preferably formed by a printing method that can use an ionizing curable ink, such as offset printing, flexographic printing, ink jet printing, or screen printing, and particularly, formed by offset printing. It is particularly preferable to do this. Moreover, it is preferable to use a photocurable ink among ionizing curable inks.

  The thickness of the printing layer 15 is not particularly limited, and can be appropriately designed to achieve a desired design, but is usually about 0.1 to 10 μm.

(Base material layer)
The base material layer 12 is made of paper. Since this paper becomes a basic material constituting the heat insulating container, it is possible to use paper having formability, bending resistance, rigidity, waist, strength and the like. As paper, for example, it is a main strength material, and uses various types of paper base materials such as high-size bleached or unbleached paper base, or pure white roll paper, kraft paper, paperboard, processed paper, milk base paper, etc. can do. The base material layer 12 may be a laminate of a plurality of these papers. The paper has a basis weight of about 80 to 600 g / m ² , preferably about 100 to 450 g / m ² , and has a thickness of about 110 to 860 μm, preferably about 140 to 640 μm. .

As described above, moisture contained in the paper constituting the base material layer 12 is required for foaming the cover layer 11A. Therefore, the above-mentioned cover layer 11A and the water vapor blocking layer 13 described later are provided on the base material layer 12. The paper constituting the base material layer 12 in any stage such as a stage before being provided, or at the same time as these are provided, and further, a stage before heating the laminated body 10A for the heat insulating container is formed. You may perform the moisture adjustment process of adjusting a moisture content. Depending on how much the cover layer 11A is foamed, for example, it is preferable to adjust the water content in the paper to be about 2 to 8%, and when using paper with a basis weight of 250 g / m ^2. In that case, it is preferable to perform the moisture adjustment step. The specific method of the moisture adjustment step is not particularly limited, and for example, paper may be soaked in water.

(Water vapor barrier)
In the heat insulating container laminates 10 </ b> A and 10 according to the present embodiment, the water vapor blocking layer 13 is provided on the inner surface side of the base material layer 12. The layer is a layer that functions to block water vapor generated from the paper constituting the base material layer 12 and efficiently send the generated water vapor to the cover layer 11A side. There is no particular limitation. For example, by using a resin whose melting point is 5 degrees or more higher than that of the resin constituting the cover layer, the water vapor blocking function is excellent, and in addition, the pinhole resistance is also excellent.

  Examples of the material of the water vapor blocking layer 13 include polyethylene resin (C), clay (D), and polypropylene.

Among these, as the water vapor barrier layer 13, a polyethylene resin (C) is preferable, and since the heat insulation is excellent, the density is preferably in the range of 925 to 970 kg / m ³ , more preferably 930 to 970 kg / m ³ , and still more preferably. Is 935-965 kg / m ³ .

  The polyethylene resin (C) is an ethylene homopolymer, or an ethylene / α-olefin copolymer, and a composition thereof, and the molecular chain may be linear and has 6 or more carbon atoms. It may have a long chain branch. Such a polyethylene-based resin (C) is not particularly limited, and it is sufficient that the density range is not exceeded.

  Examples of the ethylene homopolymer include medium / low pressure ethylene homopolymer, high pressure low density polyethylene, and the like. The medium / low pressure ethylene homopolymer can be obtained by a conventionally known medium / low pressure ion polymerization method. The high pressure method low density polyethylene can be obtained by a conventionally known high pressure radical polymerization method.

  Examples of the α-olefin used in the ethylene / α-olefin copolymer include propylene, 1-butene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-pentene, 1-hexene and 1-heptene. 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene and the like, and one or more of these may be used. The method for obtaining the ethylene / α-olefin copolymer is not particularly limited, and examples thereof include a high / medium / low pressure ion polymerization method using a Ziegler-Natta catalyst, a Philips catalyst, or a metallocene catalyst. Such a copolymer can be conveniently selected from commercially available products.

  In the polyethylene resin (C), additives generally used for polyolefin resins such as an antioxidant, a light stabilizer, an antistatic agent, a lubricant, an antiblocking agent and the like are impaired as necessary. Although it does not matter if it is added in such a range, it is preferable that the additive is not included (no additive) because it is used as the innermost layer of the heat insulating container.

  The method for forming the water vapor barrier layer 13 composed of the polyethylene resin (C) is not particularly limited, and as with the cover layer 11, extrusion coating, pre-made film lamination, dry lamination, and the like are used.

  Moreover, although it does not specifically limit about the thickness of the water vapor | steam barrier layer 13 comprised from a polyethylene-type resin (C), Usually, it is preferable that it is about 10-50 micrometers.

  On the other hand, when clay (D) is used as a material for the water vapor barrier layer 13, that is, when the clay coat layer is used as the water vapor barrier layer 13, the clay coat layer applies a coating liquid containing clay to the base material layer 12. The clay particles are spread on the surface of the base material layer 12 on which the cover layer is not provided. The clay (D) used is not particularly limited as long as it is generally called clay or clay, but kaolin, talc, bentonite, smectite, vermiculite, mica, chlorite, kibushi clay, gyrome clay, halloysite. Mica is used. Of these, kaolin and talc are preferably used as the clay. Kaolin has excellent concealability and water absorption, and talc has low hardness (Mohs hardness 1) and excellent heat resistance. Improvement in dimensional stability can be expected.

  The clay coat layer preferably contains calcium carbonate, titanium dioxide, amorphous silica, expandable barium sulfate, satin white and the like as a pigment in addition to clay. By using calcium carbonate or titanium dioxide as the pigment, the smoothness of the surface of the clay coat layer can be increased and the concealability can be increased. Furthermore, calcium carbonate is preferably used because it is inexpensive.

  The coating liquid for coating the clay coat layer contains the above clay, a binder, and, if necessary, other pigments and additives in a solvent. As the solvent, water, alcohol or the like is usually used. The binder is usually a latex binder (eg, styrene butadiene latex, acrylic latex vinyl acetate latex), water soluble binder (eg starch (modified starch, oxidized starch, hydroxyethyl etherified starch, phosphate ester). Modified starch), polyvinyl alcohol, casein and the like. Examples of additives that can be used include pigment dispersants, antifoaming agents, antifoaming agents, viscosity modifiers, lubricants, water resistance agents, water retention agents, coloring materials, and printability improvers.

  The blending ratio of the clay coating layer coating solution is not particularly limited, but is preferably about clay: pigment: binder = 1-20%: 50-90%: 10-30%.

  The coating method of the clay coat layer is not particularly limited, and a conventionally known coating method is used, but a coating method such as air knife coating, blade coating, short dwell coating, cast coating or the like is used.

Although the coating amount and thickness of the clay coat layer are not particularly limited, the basis weight after drying is usually 5 to 40 g / m ² , preferably 10 to 40 g / m ² . If the basis weight after drying is less than 5 g / m ² , water vapor generated from the paper constituting the base material layer 12 cannot be effectively blocked, and the cover layer 11 cannot be brought into a desired foamed state. If the basis weight after drying exceeds 40 g / m ² , the overall thickness of the laminated body 10 for a heat-insulating container may become too thick, and the suitability for production may deteriorate.

  In addition, since the material in which the clay coat layer which consists of the above-mentioned material etc. was already formed in the base material layer 12 which consists of paper is marketed now, you may use this. In this case, another layer may be provided at an appropriate position.

  Further, in a normal case, the clay coat layer is provided in order to improve the printability of paper. This is because printing quality is improved when printing is performed on paper on which the clay coat layer is formed. In the heat insulating container laminate 10 according to the present embodiment, the clay coat layer is formed on the inner side of the base material layer 12, that is, on the surface on which the printed layer is not provided in the heat insulating container laminate 10. In that the water vapor generated from the paper is prevented from permeating and the water vapor flows out to the cover layer 11 side, the operational effect is different from the conventional clay coat layer.

  The water vapor barrier layer 13 is not necessarily a single layer and may have a laminated structure of two or more layers. For example, a polyethylene-based resin may be laminated on the inner surface of the clay coat layer in order to impart box making properties.

(Other layers)
In the laminated bodies 10A and 10 for a heat insulating container according to the present embodiment, layers that exhibit various functions may be included in addition to the above-described layers.

  For example, in the case where barrier properties are imparted to the laminate for a heat insulating container according to the present embodiment, a PET film, a film in which an inorganic oxide is deposited on the inner side of the water vapor barrier layer 13, or a metal foil such as an aluminum foil A barrier layer made of MX nylon or the like may be provided.

  Moreover, you may provide conventionally well-known various contact bonding layers in order to improve the adhesiveness of each layer between each layer mentioned above.

(Insulated container and method for producing insulated container)
Below, the insulated container concerning embodiment of this invention and the manufacturing method of a thermally insulated container are demonstrated.

  The heat insulation container according to the present embodiment is a heat insulation container having a body part and a bottom part, and at least the body part is constituted by the laminated body for a heat insulation container 10 and 10A described above. That is, the cover layer of the laminated body for a heat insulating container constituting the body part of the heat insulating container according to the present embodiment may be in a state before foaming or in a state after foaming, but heat insulation as a final product. The cover layer of the container is in a state after foaming.

  As a manufacturing method of such a heat insulating container, after forming the laminated body 10A (before foaming) for the heat insulating container according to the present embodiment, it is punched into a blank shape of the container, and in some cases, the end face is skived and hemmed. As a heat-insulating container, the bottom part in the molding machine and if necessary, the top part is heat-sealed by hot air heating, flame heating, etc. to form a container shape, and then the cover layer is foamed by heating. Also good. In addition, the manufacturing method is not limited to this, and the cover layer may be foamed by heating after punching the laminated body 10A for a heat insulating container into a blank shape of the container, and then molded by a molding machine. Furthermore, the cover layer may be foamed by heating the laminate for a heat insulating container, and then punched into a blank shape of the container and molded by a molding machine.

  About the shape of this heat insulation container, what is necessary is just to determine suitably according to a use, the objective, etc. For example, shapes, such as a gable top type, a brick type, a flat top type, a tray type, a cup type etc. are mentioned. In addition, for example, a polyethylene cap, a pull tab type opening mechanism, or the like may be appropriately provided at the spout of the heat insulating container.

  The contents filled in the heat insulating container according to the present embodiment are not particularly limited, and various solids and liquids can be used as the contents. For example, when the shape of the heat insulating container is a cup shape, the contents may be dry noodles, miso soup, various soups, and the like.

(Preparation of laminated body for heat insulation container)
Extrusion from the back of the base material layer composed of paper through a T-die at a temperature of 310 ° C., and extrusion blocking so that the take-off speed is 100 m / min, the air gap length is 140 mm, and the thickness is 40 μm. A layer was formed. Furthermore, the surface layer and the cover layer were formed on the surface of the base material layer by co-pressing the surface layer and the cover layer at a take-up speed of 60 m / min. Next, a white ink was printed on the entire surface layer with a calibrator, and then a color ink was printed on the pattern to obtain a laminate for a heat insulating container before foaming.

Example 1
The laminated body for heat insulation containers of Example 1 which consists of the following structures by said preparation method was obtained.
·Layer structure:
Print layer / surface layer / cover layer / base material layer / water vapor barrier layer / print layer:
Contains 16.2% by mass of urethane structure polymer and 1% by mass of photopolymerization initiator by-product. Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
Melting temperature 121 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer:
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
40 μm thick

(Example 2)
The laminated body for heat insulation containers of Example 2 which consists of the following structures by said production method was obtained.
·Layer structure:
Print layer / surface layer / cover layer / base material layer / water vapor barrier layer / print layer:
Contains 40% by mass of urethane structure polymer and 1% by mass of photopolymerization initiator by-product. Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
Melting temperature 121 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer:
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
40 μm thickness

(Example 3)
The laminated body for heat insulation containers of Example 3 which consists of the following structures by said production method was obtained.
·Layer structure:
Print layer / surface layer / cover layer / base material layer / water vapor barrier layer / print layer:
Contains 85% by weight of urethane structure polymer and 1% by weight of photopolymerization initiator by-product. Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
Melting temperature 121 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer:
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
40 μm thick

Example 4
By extruding only the cover layer in the above production method, a laminate for a heat insulating container of Example 4 having the following configuration was obtained.
·Layer structure:
Print layer / cover layer / base material layer / water vapor barrier layer / print layer:
40% by mass of urethane structure polymer and 1% by mass of photopolymerization initiator by-product-Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer:
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
40 μm thickness

(Example 5)
While extruding only the cover layer in the above production method and making the water vapor blocking layer have a three-layer structure, a laminate for a heat insulating container of Example 5 having the following configuration was obtained.
·Layer structure:
Print layer / cover layer / base material layer / water vapor barrier layer / print layer of three-layer structure:
40% by mass of urethane structure polymer and 1% by mass of photopolymerization initiator by-product-Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer (1):
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
Thickness 15μm
・ Water vapor barrier layer (2):
PET (T-4100 manufactured by Toyobo Co., Ltd.)
Thickness 12μm
・ Water vapor barrier layer (3):
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
30 μm thick

(Comparative Example 1)
The laminated body for heat insulation containers of the comparative example 1 which consists of the following structures by said production method was obtained.
·Layer structure:
Print layer / surface layer / cover layer / base material layer / water vapor barrier layer / print layer:
Contains 10% by mass of urethane structure polymer and 1% by mass of photopolymerization initiator by-product. Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
Melting temperature 121 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer:
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
40 μm thickness

(Comparative Example 2)
The laminated body for heat insulation containers of the comparative example 2 which consists of the following structures by said preparation method was obtained.
·Layer structure:
Print layer / surface layer / cover layer / base material layer / water vapor barrier layer / print layer:
Contains 50% by weight of the polyester structure polymer and 1% by weight of a photopolymerization initiator by-product. Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
Melting temperature 121 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer:
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
40 μm thickness

(Comparative Example 3)
The laminated body for heat insulation containers of the comparative example 3 which consists of the following structures by said production method was obtained.
·Layer structure:
Print layer / surface layer / cover layer / base material layer / water vapor barrier layer / print layer:
Contains 50% by weight of the polyol structure polymer and 1% by weight of a photopolymerization initiator by-product. Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
Melting temperature 121 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer:
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
40 μm thick

(Comparative Example 4)
The laminated body for heat insulation containers of the comparative example 4 which consists of the following structures by said production method was obtained.
·Layer structure:
Print layer / surface layer / cover layer / base material layer / water vapor barrier layer / print layer:
10 mass% of epoxy structure polymer and 1 mass% of by-product of photopolymerization initiator ・ Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
Melting temperature 121 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer:
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
40 μm thick

(Comparative Example 5)
By the above production method, a laminated body for a heat insulating container of Comparative Example 5 having the following configuration was obtained.
·Layer structure:
Print layer / surface layer / cover layer / base material layer / water vapor barrier layer / print layer:
10% by mass of a chlorine-based PP structure polymer and 1% by mass of a photopolymerization initiator by-product. Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
Melting temperature 121 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 07C03C)
Density 917kg / m ³
Melting temperature 107 ° C
60μm thickness before foaming
・ Base material layer:
Nippon Paper Industries Co., Ltd. Cup base paper Basis weight 280g / m ²
・ Water vapor barrier layer:
MDPE (Tosoh Corporation Petrocene LW04-1)
Density 940kg / m ³
Melting temperature 133 ° C
40 μm thick

  About each laminated body for heat insulation containers of the said Examples 1-5 and Comparative Examples 1-5, foaming thickness, the external appearance, and the designability were evaluated. Each evaluation is as follows.

(Foam thickness)
The laminates for heat insulating containers of Examples 1 to 5 and Comparative Examples 1 to 5 are cut into a cylindrical shape, and the cover layer is foamed by heating at 117 ° C. for 6 minutes using a convection oven. The thickness was evaluated.
○: 600 μm or more ×: less than 600 μm

(appearance)
It evaluated by observing visually about the surface of the printing layer after foaming.
○: surface smoothness is good ×: surface smoothness is inferior or film cracking occurs

(Creativity)
Evaluated by visually observing the surface of the printed layer after foaming: Excellent surface smoothness and excellent pattern reproducibility ×: Inferior surface smoothness or poor pattern reproducibility

(Evaluation results)
Table 1 shows the evaluation results for the foam thickness, appearance, and design properties.

  As is clear from Table 1 above, it can be seen that according to the laminated body for a heat insulating container according to the example of the present invention, all evaluation results of the foam thickness, the appearance, and the design are excellent.

10 ... Laminated body for insulated container (after foaming)
10A ... Laminated body for heat insulation container (before foaming)
11 ... Cover layer (after foaming)
11A ... cover layer (before foaming)
12 ... Base material layer 13 ... Water vapor barrier layer 15 ... Print layer 16 ... Surface layer

Claims (12)

From the outer surface side, a laminate for a heat insulating container having at least a printed layer, a cover layer, a substrate layer composed of paper, and a water vapor blocking layer that blocks water vapor generated from the paper constituting the substrate layer,
The cover layer is made of a foamable thermoplastic resin,
The printing layer includes a binder,
The binder includes a urethane structure polymer, and one or both of a photopolymerization initiator and a byproduct of the photopolymerization initiator,
A laminate for a heat-insulating container, wherein the ratio of the urethane structure polymer to the total mass of the printing layer is 15% by mass or more and 90% by mass or less.   The binder contains a by-product of a photopolymerization initiator, and the proportion thereof is 0.2% by mass or more and 1.5% by mass or less based on the total mass of the printing layer. Item 2. The laminate for a heat-insulating container according to Item 1.   The laminate for a heat insulating container according to claim 1 or 2, wherein the foamable thermoplastic resin is any one of high-pressure low-density polyethylene, polypropylene, and an ethylene / α-olefin copolymer.   It has a surface layer between the said printing layer and cover layer, The laminated body for heat insulation containers as described in any one of Claims 1-3 characterized by the above-mentioned.   The said cover layer is foaming, The laminated body for heat insulation containers as described in any one of Claims 1-4 characterized by the above-mentioned.   At least one part is comprised with the laminated body for heat insulation containers as described in any one of the said Claims 1-5, The heat insulation container characterized by the above-mentioned. Have a torso and a bottom,
The at least said trunk | drum is comprised by the laminated body for heat insulation containers as described in any one of the said Claims 1-5, The heat insulation container of Claim 6 characterized by the above-mentioned. From the outer surface side, a printed layer, a cover layer, a base material layer composed of paper, and a water vapor barrier layer that shields water vapor generated from the paper constituting the base material layer, at least a method for producing a laminate for a heat insulating container There,
Preparing a preparation having at least the cover layer, the base material layer, and the water vapor blocking layer;
A printing step of printing using an ionizing curable ink on the cover layer in the preparation;
An irradiation step of irradiating ionizing radiation to the ionization curable ink printed on the cover layer to form a printed layer;
The manufacturing method of the laminated body for heat insulation containers characterized by including. A laminate for a heat-insulating container having at least a printed layer, a surface layer, a cover layer, a substrate layer composed of paper, and a water vapor blocking layer that blocks water vapor generated from the paper constituting the substrate layer from the outer surface side A manufacturing method comprising:
Preparing a preparation having at least the surface layer, the cover layer, the base material layer, and the water vapor blocking layer;
A printing step of printing using an ionizing curable ink on the surface layer in the preparation;
An irradiation step of irradiating ionizing radiation to the ionization curable ink printed on the surface layer to form a printed layer;
The manufacturing method of the laminated body for heat insulation containers characterized by including. Preparing a laminate for a heat-insulating container manufactured by the method for manufacturing a laminate for a heat-insulating container according to claim 8 or 9,
A punching step of punching the laminate for a heat insulating container into a predetermined shape;
A molding step of molding the punched laminated body for a heat insulating container into a container shape;
A heating step of foaming the cover layer by heating the laminate for a heat insulating container molded into the container shape;
The manufacturing method of the heat insulation container characterized by including. Preparing a laminate for a heat-insulating container manufactured by the method for manufacturing a laminate for a heat-insulating container according to claim 8 or 9,
A punching step of punching the laminate for a heat insulating container into a predetermined shape;
A heating step of foaming the cover layer by heating the punched laminated body for a thermal insulation container;
A molding step of molding the laminate for a heat-insulating container in a state where the cover layer is foamed into a container shape;
The manufacturing method of the heat insulation container characterized by including. Preparing a laminate for a heat-insulating container manufactured by the method for manufacturing a laminate for a heat-insulating container according to claim 8 or 9,
A heating step of heating the laminate for a heat insulating container to foam the cover layer;
A punching step of punching the laminate for a heat insulating container in a state where the cover layer is foamed into a predetermined shape;
A molding step of molding the punched laminated body for a heat insulating container into a container shape;
The manufacturing method of the heat insulation container characterized by including.

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