JPWO2017073537A1 - Laminated body for heat insulation container, heat insulation container and method for producing heat insulation container - Google Patents

Abstract

To provide a laminate for a heat insulating container, which is a material for a heat insulating container having a printed layer on the surface, which is excellent in smoothness of the surface of the printed layer even after foaming and can realize a desired design. In the laminate for a heat insulating container having at least a printed layer, a surface layer, a cover layer, a base material layer made of paper, and a water vapor blocking layer for blocking water vapor generated from the paper constituting the base material layer from the outer surface side The cover layer is made of high-pressure low-density polyethylene, and the surface layer has a melting point temperature measured by JIS K6922-2 (2005). The melting point temperature of the high-pressure low-density polyethylene constituting the cover layer It is comprised from higher polyethylene-type resin, the said printing layer contains urethane resin as a binder, and the ratio of the said urethane resin with respect to the total mass of the total solid of a printing layer shall be 18 mass% or more.

Description

  The present invention relates to a laminate for a heat insulating container, a heat insulating container, and a method for manufacturing 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 laminated body for a heat insulating container, a printed layer for imparting designability may be provided on the resin on the surface side. However, if there is a part where the printed layer is provided, a part where it is not provided, and a part where the printed layer is provided, even if the printed layer is thick or thin, Depending on the part, the degree of foaming of the resin on the surface side located under each part may differ, which may cause a step on the surface of the printed layer and impair the design. It was.

  The present invention has been made in such a situation, and is a laminated body for a heat insulating container provided with a printing layer on the surface, and the surface layer can be foamed to a desired degree. A laminated body for a heat insulating container having excellent surface smoothness and capable of realizing a desired design, a heat insulating container formed using the laminated body for a heat insulating container, and a heat insulating container using the laminated body for a heat insulating container It is a main subject to provide a manufacturing method.

  In order to solve the above problems, the present invention provides a substrate layer composed of a printed layer, a surface layer, a cover layer, paper, and a water vapor barrier that blocks water vapor generated from the paper constituting the substrate layer from the outer surface side. The cover layer is composed of at least a high-pressure method low-density polyethylene, and the surface layer has a melting point measured according to JIS K6922-2 (2010). The cover layer is made of a polyethylene-based resin having a melting point higher than that of the high-pressure method low-density polyethylene, and the printing layer contains a urethane resin as a binder, and the total mass of the printing layer with respect to the total mass The ratio of the urethane resin is 18% by mass or more.

  In the above invention, the printing layer has a laminated structure in which a plurality of printing layers are stacked, and all the printing layers contain a urethane resin as a binder, and the total solid content of each printing layer The ratio of the urethane resin to the mass may be 18% by mass or more.

  The ratio of the thickness of the surface layer to the thickness of the cover layer before foaming may be 1: 2 to 1:30.

  The cover layer may be foamed.

  The ratio of the thickness of the surface layer to the thickness of the cover layer after foaming may be 1:15 to 1: 360.

  The cover layer after foaming may have a thickness of 300 to 900 μm.

  Another invention of the present application for solving the above-mentioned problem is a heat insulating container having a body part and a bottom part, wherein at least the body part is constituted by the laminate for a heat insulating container of the present invention. .

  Furthermore, another invention of the present application for solving the above-mentioned problem is a method for manufacturing a heat insulating container having a body part and a bottom part, wherein at least the body part is constituted by the laminate for a heat insulating container of the present invention, and thereafter The cover layer of the laminated body for heat insulation containers is foamed by heating the laminated body for heat insulation containers that constitutes the body portion.

  According to the laminated body for a heat-insulating container of the present invention, the surface layer can be foamed to a desired degree even though the printed layer is provided on the surface layer. Moreover, even after the surface layer is foamed, the smoothness of the surface of the printed layer can be made good. Therefore, a desired design can be realized.

  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.

  Also in the manufacturing method of 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.

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, the heat insulation container, and the manufacturing method of a 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.

  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 at least a high pressure method low density polyethylene. 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. it is preferred, more preferably 890~935kg / ^{m 3,} still more preferably from 900~925kg / ^{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. Since the foam 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 ) (Pa) of 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 5 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 700 μm because of excellent heat insulation and foam appearance.

(Surface layer)
In the laminated bodies 10A and 10 for heat insulating containers according to the present embodiment, the melting points measured by JIS K6922-2 (2010) constitute the cover layers 11A and 11 on the cover layers 11A and 11. The high-pressure method low-density polyethylene (B) is characterized in that a surface layer composed of a polyethylene resin (A) higher than the melting point of the high-pressure method low-density polyethylene (B) is provided. 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. More specifically, for example, even if the printing layer 15 described later is composed of a white ink printing portion and a color ink printing portion, the step between the white ink printing portion and the color ink printing portion is 200 μm. It becomes possible to suppress to less than.

  The polyethylene resin (A) constituting the surface layer 16 includes medium / low pressure ethylene homopolymer, high pressure low density polyethylene, ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic. Examples include ethyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / α-olefin copolymer (A), medium / low pressure ethylene homopolymer (A). However, it is particularly preferable because the expansion ratio of the cover layer 11A can be improved and the appearance of the laminate is also 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 the preferable ratio by using paper having a large basis weight or paper having a high water content as the base material 12 or by increasing the thickness of the cover layer 11A before foaming. It is possible to make the thickness more than this, but even if it is thicker than this, the heat insulation and design will not be improved dramatically, and when used for heat insulation containers of normal size, It is considered to be.

(Print layer)
In the heat insulating container laminates 10A and 10 according to the embodiment of the present invention, a printing layer 15 is provided on the surface layer 16, and the printing layer 15 includes a urethane resin as a binder resin, and is printed. Another characteristic is that the ratio of the urethane resin to the total mass of the total solid content of the layer is 18% by mass or more. By using the printing layer 15 containing such a specific binder, the followability of the printing layer 15 can be improved, and when the cover layer 11A is in a foamed state, the foaming of the cover layer 11A can be followed well. Moreover, surface smoothness can be ensured and excellent design properties can be exhibited. 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 printing layer 15 is not necessarily a single layer, and as shown in FIGS. 1 and 2, a plurality of printing layers (in FIG. 1 and FIG. 2, three printing layers 15a, 15b, and 15c). In this case, all the printing layers (15a, 15b, and 15c) include a urethane resin as a binder, and each printing layer (15a, 15b, And the ratio of the urethane resin to the total mass of the total solid content of 15c) is preferably 18% by mass or more.

  Here, the “urethane resin” referred to in the present specification intends a broad meaning urethane resin including a modified urethane resin such as a general urethane resin or a urethane urea resin conventionally used in the technical field. Moreover, the urethane resin 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 the urethane resin. Although it does not specifically limit, In this invention, the urethane resin obtained by making a polyol compound and organic diisocyanate react is mentioned as one preferable embodiment of a urethane resin. Another embodiment includes a modified urethane resin obtained by modifying a prepolymer of a urethane resin with an amine compound or an amide compound.

  In such a component of the printing layer 15, particularly limited except that the urethane resin is included as a binder resin and the ratio of the urethane resin to the total mass of the total solid content of the printing layer is 18% by mass or more. In order to realize a desired design, additives such as various pigments and dyes, and further wax can be freely used.

  In addition to urethane resins, binder resins used include nitrified cotton resins, vinyl copolymers, polyamide resins, alkyd resins, acrylic resins, rosin resins, dimer acid resins, maleic acid resins, and chlorinated polypropylene resins. Terpene resin, ketone resin, butyral resin, petroleum resin and the like. 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 print layer 15 is not particularly limited, but may be formed by gravure printing, offset printing, or the like.

  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 so that the water content in the paper is 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.

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

The density of the polyethylene-based resin (C) as the water vapor blocking layer 13 is preferably in the range of 925 to 970 kg / m ³ , more preferably 930 to 970 kg / m ³ , and still more preferably 935 because of excellent heat insulation. it is a ~965kg / ^{m 3.}

  Such a polyethylene resin (C) has a higher melting point than the high-pressure method low-density polyethylene (B) constituting the cover layer 11A, and water vapor blocking performance is also superior to that of the high-pressure method low-density polyethylene (B). In addition, since it has excellent pinhole resistance, it can be suitably used as the water vapor blocking layer 13 in the laminated body 10A, 10 for the heat insulating container according to the present embodiment.

  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 (D). 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 (D), 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.

The coating amount and thickness of the clay coat layer is not particularly limited, the basis weight after drying was 5 to 40 g / ^{m 2,} preferably 10 to 40 g / ^{m 2.} When 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 efficiently 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 production suitability 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 laminated body 10 for a heat insulating container according to the present embodiment, the clay coat layer is formed on the inner side of the base material layer 12, that is, the surface of the packaging material 10 on which the printing layer is not provided, and from the paper of the base material layer 12 In the point which prevents the water vapor | steam which generate | occur | produces permeate | transmitting and the said water vapor | steam comes out to the cover layer 11 side, the 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 method for manufacturing such a heat insulating container, at least the body portion is constituted by the heat insulating container laminate 10A before the cover layer 11A is foamed, and the heat insulating container laminate 10A is heated to laminate the heat insulating container. The body cover layer may be foamed. More specifically, after forming the laminated body 10A for heat insulation container according to the present embodiment (before foaming), punching, skive hemming the end face so that the contents do not contact the end face, the bottom in the molding machine, If necessary, the top portion may be heat-sealed by hot air heating, flame heating, or the like to form a container, and then heated to foam the cover layer to form a heat insulating container.

  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 shape of a gable top type, a brick type, a flat top 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.

  The present invention will be described more specifically with reference to examples and comparative examples.

(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. Then, after a white ink was printed on the entire surface layer with a gravure proofing machine, a color ink was printed in a pattern to obtain a laminate for a heat insulating container before foaming. Then, the laminated body for a heat insulating container was cut into a columnar shape and heated at 120 ° C. for 5 minutes using a convection oven to foam the cover layer to obtain a foamed heat insulating container laminated body.

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:
Ratio of urethane resin to the total mass of the total solid content of the printed layer after drying 35% by mass
・ Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
MFR 20g / 10min Melting temperature 121 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 212)
Density 919kg / m ³
MFR 13g / 10min Melting temperature 107 ° C
60μm thickness before foaming
700μm thickness after foaming (including surface layer)
・ 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
MFR 7g / 10min 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:
Ratio of urethane resin to the total mass of the total solid content of the printed layer after drying 35% by mass
・ Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
MFR 20g / 10min Melting temperature 121 ° C
5 μm thick
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 212)
Density 919kg / m ³
MFR 13g / 10min Melting temperature 107 ° C
60μm thickness before foaming
700μm thickness after foaming (including surface layer)
・ 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
MFR 7g / 10min Melting temperature 133 ° C
40 μm thick

(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:
Ratio of urethane resin to the total mass of the total solid content of the printed layer after drying 35% by mass
・ Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
MFR 20g / 10min Melting temperature 121 ° C
Thickness 2.5μm
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 212)
Density 919kg / m ³
Melting temperature 107 ° C
MFR13g / 10min Thickness before foaming 70μm
750μm thickness after foaming (including surface layer)
・ 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
MFR 7g / 10min Melting temperature 133 ° C
40 μm thick

Example 4
The laminated body for heat insulation containers of 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:
Ratio of urethane resin to the total mass of the total solid content of the printed layer after drying 35% by mass
・ Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M65)
Density 920kg / m ³
MFR 20g / 10min Melting temperature 120 ° C
10 μm thickness
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 212)
Density 919kg / m ³
Melting temperature 107 ° C
MFR13g / 10min Thickness before foaming 60μm
700μm thickness after foaming (including surface layer)
・ 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
MFR 7g / 10min Melting temperature 133 ° C
40 μm thick

(Example 5)
The laminated body for heat insulation containers of Example 5 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:
Ratio of urethane resin to the total mass of the total solid content of the printed layer after drying 25% by mass
・ Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
MFR 20g / 10min Melting temperature 121 ° C
Thickness 5μm
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 212)
Density 919kg / m ³
MFR 13g / 10min Melting temperature 107 ° C
60μm thickness before foaming
Thickness after foaming 600μm (including surface layer)
・ 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
MFR 7g / 10min Melting temperature 133 ° C
40 μm thick

(Example 6)
The laminated body for heat insulation containers of Example 6 which consists of the following structures was obtained with said preparation method.
·Layer structure:
Print layer / surface layer / cover layer / base material layer / water vapor barrier layer / print layer:
18% by mass of urethane resin relative to the total mass of the total solid content of the printed layer after drying
・ Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
MFR 20g / 10min Melting temperature 121 ° C
Thickness 5μm
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 212)
Density 919kg / m ³
MFR 13g / 10min Melting temperature 107 ° C
60μm thickness before foaming
400μm thickness after foaming (including surface layer)
・ 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
MFR 7g / 10min Melting temperature 133 ° C
40 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:
Ratio of urethane resin to the total mass of the total solid content of the printed layer after drying 35% by mass
・ Surface layer:
LDPE (Petrocene 213 manufactured by Tosoh Corporation)
Density 918kg / m ³
Melting temperature 102 ° C
MFR 8g / 10min Thickness 10μm
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 212)
Density 919kg / m ³
MFR 13g / 10min Melting temperature 107 ° C
60μm thickness before foaming
650μm thickness after foaming (including surface layer)
・ 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
MFR 7g / 10min Melting temperature 133 ° C
40 μm thick

(Comparative 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:
Ratio of urethane resin to the total mass of the total solid content of the printed layer after drying 10% by mass
・ Surface layer:
LLDPE (Tosoh Corporation Nipolon-L M72)
Density 925kg / m ³
MFR 20g / 10min Melting temperature 121 ° C
5 μm thick
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 212)
Density 919kg / m ³
MFR 13g / 10min Melting temperature 107 ° C
60μm thickness before foaming
250 μm thickness after foaming (including surface layer)
・ 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
MFR 7g / 10min Melting temperature 133 ° C
40 μm thick

(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 / cover layer / base material layer / water vapor barrier layer / print layer:
Ratio of urethane resin to the total mass of the total solid content of the printed layer after drying 35% by mass
・ Cover layer:
LDPE (Tosoh Co., Ltd. Petrocene 212)
Density 919kg / m ³
MFR 13g / 10min Melting temperature 107 ° C
60μm thickness before foaming
700μm thickness after foaming (including surface layer)
・ 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
MFR 7g / 10min Melting temperature 133 ° C
40 μm thick

  About the laminated body for heat insulation containers of the said Examples 1-6 and Comparative Examples 1-3, foam thickness, foam followability, and foam appearance were evaluated. Each evaluation is as follows.

(Foam thickness)
The thickness before and after foaming was measured using a thickness meter (Dial Thickness Gauge G: manufactured by Ozaki Mfg. Co., Ltd.), and the sum of the thicknesses of the surface layer and the cover layer of the portion where white ink and color ink were laminated was calculated from the difference. And evaluated according to the following criteria.
A: 450 μm or more B: 300 μm or more and less than 450 μm C: Less than 300 μm

(Foaming followability)
Using the thickness gauge (Dial Thickness Gauge G: manufactured by Ozaki Mfg. Co., Ltd.), the thickness of the white ink printing part and the thickness of the color ink printing part laminated on this white ink printing part on the surface of the printing layer after foaming The difference was taken as the step. And this level | step difference was evaluated according to the following references | standards.
A: Step difference between the white ink printing portion and the color ink portion is less than 100 μm B: Step difference between the white ink printing portion and the color ink portion is not less than 100 μm and less than 200 μm C: Step difference between the white ink printing portion and the color ink portion is not less than 200 μm

(Foam appearance)
The appearance of the color ink printed part after foaming was visually observed and touched, and the surface smoothness was evaluated according to the following criteria.
A: The surface is smooth and does not feel unevenness.
B: Slight irregularities are felt.
C: It is quite uneven and feels rough.

(Evaluation results)
Table 1 shows the evaluation results for each of the foam thickness, foam followability, and foam appearance.

  As can be seen from Table 1 above, according to the laminated body for a heat insulating container according to the example of the present invention, it can be seen that all the evaluation results of the foam thickness, the foam followability, and the foam appearance are excellent. On the other hand, in the laminated body for a heat insulating container according to Comparative Example 1, since the melting point of the resin constituting the surface layer is lower than the melting point of the resin constituting the cover layer, the evaluation of foam followability and foam appearance is low. It has become. Moreover, in the laminated body for heat insulation containers concerning the comparative example 2, since the ratio of the urethane resin with respect to the total mass of the total solid of a printing layer is less than 18 mass%, foaming thickness is inadequate. Moreover, in the laminated body for heat insulation containers concerning the comparative example 3, since the surface layer is not provided, evaluation of foaming followability and foaming appearance is low.

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 (8)

A laminate for a heat insulating container having at least a printed layer, a surface layer, a cover layer, a base material layer made of paper, and a water vapor blocking layer for blocking water vapor generated from the paper constituting the base material layer from the outer surface side. There,
The cover layer is composed of at least a high pressure method low density polyethylene,
The surface layer is made of a polyethylene-based resin having a melting point measured by JIS K6922-2 (2010) higher than the melting point of the high-pressure low-density polyethylene constituting the cover layer,
The printing layer contains a urethane resin as a binder, and the ratio of the urethane resin to the total mass of the total solid content of the printing layer is 18% by mass or more.
A laminate for a heat-insulating container.   The printing layer has a laminated structure in which a plurality of printing layers are stacked, all the printing layers contain a urethane resin as a binder, and the ratio of the urethane resin to the total mass of the total solid content of each printing layer is It is 18 mass% or more, The laminated body for heat insulation containers of Claim 1 characterized by the above-mentioned.   The laminate for a heat-insulating container according to claim 1 or 2, wherein a ratio between the thickness of the surface layer and the thickness of the cover layer before foaming is 1: 2 to 1:30.   The said cover layer is foaming, The laminated body for heat insulation containers as described in any one of Claims 1-3 characterized by the above-mentioned.   The laminate for a heat-insulating container according to claim 4, wherein a ratio of the thickness of the surface layer to the thickness of the cover layer after foaming is 1:15 to 1: 360.   The laminate for a heat-insulating container according to claim 4 or 5, wherein the cover layer after foaming has a thickness of 300 to 900 µm. An insulated container having a trunk and a bottom,
The at least said trunk | drum is comprised with the laminated body for heat insulation containers as described in any one of the said Claims 1-6, The heat insulation container characterized by the above-mentioned. A method for manufacturing a heat insulating container having a trunk and a bottom,
At least the body part is constituted by the laminate for a heat insulating container according to any one of claims 1 to 3,
Then, the cover layer of the laminated body for heat insulation containers is made to foam by heating the laminated body for heat insulation containers which comprises the said trunk | drum, The manufacturing method of the heat insulation container characterized by the above-mentioned.

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