JP6507705B2 - Foam laminate - Google Patents

Description

  [Technical Field] The present invention relates to a foam laminate having a large thickness of a foam layer and exhibiting good heat insulation and excellent gas barrier properties.

  Heretofore, many containers made of synthetic resin, particularly polystyrene, have been used as containers having heat insulating properties. However, expanded polystyrene containers have disadvantages such as high environmental load at the time of disposal and poor printability, and substitution with other materials is being studied. Under such circumstances, a container in which a heat-insulating layer is formed by laminating corrugated paper on the outer peripheral surface of the paper cup barrel, a container in which a laminate of non-woven pulp and coated paper is joined to the outer peripheral surface of the paper cup Developed and used.

  However, both methods are disadvantageous in that they are not easy to process and form, and cost increases. Therefore, a technique of laminating a low melting point thermoplastic synthetic resin film on at least one surface of a substrate containing water, and heating it, thereby causing the synthetic resin film to be unevenly formed by utilizing the water contained in the substrate. Have been devised (see, for example, Patent Documents 1 to 3). However, in the material thus obtained, the thickness of the foam layer was thin and the heat insulation was insufficient.

  Also, as means for obtaining a thick foam of foam layer, a container body and a bottom plate member, and a thermoplastic resin film of high melting point is laminated on the inner wall surface of the base paper of the container body and bottom plate member A heat insulating paper container has been proposed in which a low melting point thermoplastic synthetic resin film is laminated on the outer wall surface of a base paper of a member, and the low melting point thermoplastic synthetic resin film is heat treated to foam (for example, See Patent Document 4). However, the heat insulating paper container having the thermoplastic synthetic resin of high melting point on the inner wall surface is inferior in the gas barrier property.

  Further, as a method for obtaining a foam laminate excellent in gas barrier properties, a method has been proposed in which a barrier layer made of an aluminum foil or a stretched polyester film for suppressing permeation of water vapor is provided on the inner wall surface and a sealant layer is provided thereon For example, refer to patent documents 5-6).

  However, the method of providing the barrier layer and the sealant layer uses an expensive barrier layer, is complicated in layer constitution, and inferior in cost performance.

Japanese Patent Publication No. 48-32283 Japanese Patent Application Laid-Open No. 57-110439 JP 2001-270571 A JP 2007-217024 A JP 2003-261128 A Unexamined-Japanese-Patent No. 2004-231197

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a foam laminate having a large thickness of a foam layer and exhibiting good heat insulation and excellent gas barrier properties.

  MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, the present inventors discover that a specific foam laminated body shows the outstanding thermal insulation and gas-barrier property, and came to complete this invention.

That is, at least the (A) layer is disposed adjacent to the paper base layer, and the (B) layer and the (B) layer adjacent to the paper base are adjacent to the paper base on the other side of the paper base (C) layer, and (C) layer is a foam laminate in which the (D) layer is disposed on the outer surface than the (C) layer, and the density of the (A) layer is 925 kg measured by JIS K 6922-1 (2011) / ^{m 3} or more 970 kg / ^{m 3} or less is polyethylene resin (a), (B) layer is JIS K6922-1 pressure was measured density of 910 kg / ^{m 3} or more 930 kg / ^{m 3} or less by (2011) Method low density polyethylene (b), polyethylene resin (c), (D) layer whose melting temperature measured according to JIS K6922-2 (2010) is higher than high pressure method low density polyethylene (b) Gas barrier coating agent (d The present invention relates to a foam laminate characterized in that

  Hereinafter, the present invention will be described in detail.

The density (hereinafter simply referred to as density) of the polyethylene-based resin (a) constituting the present invention as measured according to JIS K 6922-1 (2011) is excellent in heat insulation and foam stability, so it is 925 to 970 kg in the range of / ^{m 3,} preferably in the range of 935~970kg / ^{m 3,} more preferably 945~970kg / ^{m 3,} most preferably from 950~965kg / ^{m 3.} If the density of the polyethylene-based resin (a) is less than 925 kg / m ^3, it is not preferable because of poor heat insulation, and if it exceeds 970 kg / m ³ , it is not preferable because of poor foam appearance.

  The polyethylene resin (a) constituting the present invention is an ethylene homopolymer or an ethylene / α-olefin copolymer and a composition thereof, and the form of the molecular chain thereof may be linear, and has 6 carbon atoms. It may have the above long chain branching. Such a polyethylene-based resin (a) is not particularly limited, and it is sufficient if it does not deviate from the density range.

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

  Examples of the α-olefin used for the ethylene / α-olefin copolymer 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 may be used.

  The method for obtaining the ethylene / α-olefin copolymer is not particularly limited, and examples include Ziegler / Natta catalysts, Phillips catalysts, high / medium / low pressure ionic polymerization methods using metallocene catalysts, and the like. Such a copolymer can be conveniently selected from commercially available products.

Among these, low-pressure ethylene homopolymer (e) having a density of 935 to 980 kg / m ³ and / or ethylene / α-olefin having a density of 935 to 980 kg / m ³ because of excellent laminate moldability. Ethylene resin comprising 10 to 90% by weight of the copolymer (f) and 90 to 10% by weight of high-pressure low density polyethylene (g) (the total of (e), (f) and (g) is 100%) It is preferable that it is a composition (h).

  Such a low-pressure ethylene homopolymer (e) is excellent in laminating processability of the ethylene-based resin composition (h), so that the melt mass flow rate (hereinafter referred to simply as MFR) measured according to JIS K 6922-1 (2011) 6 to 100 g / 10 min is preferable, and more preferably 8 to 60 g / 10 min.

Furthermore, in the low-pressure ethylene homopolymer (e), the density is preferably in the range of 945 to 975 kg / m ³ because the laminate processability and productivity of the ethylene-based resin composition (h) are excellent.

  In such an ethylene / α-olefin copolymer (f), the MFR is preferably in the range of 6 to 100 g / 10 min, and more preferably 8 because the laminate processability of the ethylene resin composition (h) is excellent. 60 g / 10 min.

Furthermore, in the ethylene / α-olefin copolymer (f), the density is preferably in the range of 945 to 975 kg / m ³ because the laminate processability and productivity of the ethylene-based resin composition (h) are excellent.

  In the high pressure low density polyethylene (g), the MFR is preferably in the range of 0.1 to 20 g / 10 min, more preferably 0.3 to 10 g, because the extrusion laminating processability of the ethylene resin composition (h) is excellent. It is in the range of 10 minutes, most preferably 1 to 4 g / 10 minutes.

Moreover, in the high pressure method low density polyethylene (g), the density is preferably in the range of 910 to 935 kg / m ³ because the film formation stability of the ethylene-based resin composition (h) is excellent.

  The MFR of the ethylene-based resin composition (h) is preferably in the range of 1 to 50 g / 10 min, and more preferably in the range of 3 to 20 g / 10 min, because of excellent laminate formability.

  The polyethylene resin (a) constituting the present invention may be blended with other polyolefin such as polypropylene, and the blending ratio of these polyolefins is 1 to 30% by weight of the laminate formability and laminate appearance. It is preferable from the point of view.

  When mixing polyolefin with the polyethylene resin (a) constituting the present invention, a pellet mixture of pellets of the polyethylene resin (a) and pellets of the polyolefin in a solid state may be used, but a single screw extruder may be used. A mixture melt-kneaded with a twin-screw extruder, a kneader, 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 the polyethylene resin to about 300 ° C.

Furthermore, additives generally used for polyolefin resins, such as antioxidants, light stabilizers, antistatic agents, lubricants, antiblocking agents, etc., are optionally added to the polyethylene resin (a) constituting the present invention. May be added as long as the object of the present invention is not impaired.
The high pressure low density polyethylene (b) constituting the present invention can be obtained by a conventionally known high pressure radical polymerization method.

The high-pressure low-density polyethylene (b) has a density of 910 to 930 kg / m ³ , more preferably 914 to 926 kg / m ³ , and still more preferably 916 to 924 kg / m ³ because of its excellent thermal insulation and foam appearance. It is in the range of ³ . If the density of the high-pressure low density polyethylene (b) is less than 910 kg / m ^3, it is not preferable because the foam appearance is inferior, and if it exceeds 930 kg / m ³ , it is not preferable because of poor heat insulation.

  In addition, the MFR of the high-pressure low-density polyethylene (b) is preferably in the range of 10 to 30 g / 10 min because of excellent heat insulation and foam appearance, more preferably 12 to 30 g / 10 min, and still more preferably 13 It is in the range of -24 g / 10 min, most preferably 13-18 g / 10 min.

  The high-pressure low-density polyethylene (b) constituting the present invention may be blended with other polyolefins such as ethylene / α-olefin copolymer.

  When a polyolefin is mixed with the high-pressure low-density polyethylene (b) constituting the laminate of the present invention, a pellet mixture of pellets of high-pressure low-density polyethylene (b) and pellets of polyolefin mixed in a solid state Although it is good, a mixture melt-kneaded by a single screw extruder, a twin screw extruder, a kneader, 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 300 ° C. of the melting point of the polyolefin resin.

  In addition, the high-pressure low-density polyethylene (b) constituting the laminate of the present invention is generally used for polyolefin resins such as an antioxidant, a light stabilizer, an antistatic agent, a lubricant, an antiblocking agent, if necessary. Additives may be added as long as the object of the present invention is not impaired.

  The polyethylene resin (c) is excellent in the gas barrier property and the foam appearance, and therefore the melting temperature measured by JIS K6922-2 (2010) is higher than the high pressure low density polyethylene (b).

  Such polyethylene-based resin (c) is a low-pressure ethylene homopolymer, high-pressure low-density polyethylene, ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, Ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, and compositions thereof, etc. may be mentioned, but ethylene / α-olefin copolymer, low-pressure ethylene homopolymer, the expansion ratio of (B) layer In particular, the laminate appearance is excellent, and the laminate appearance is also excellent.

  There is no particular limitation on the method for obtaining such ethylene / α-olefin copolymer, and Ziegler / Natta catalyst, Phillips catalyst, high / medium / low pressure ionic polymerization method using metallocene catalyst, etc. may be exemplified. Can. Such a copolymer can be conveniently selected from commercially available products, but since the laminate appearance is excellent, an ethylene / α-olefin copolymer obtained by a polymerization method using a Ziegler-Natta catalyst is Particularly preferred.

  The thickness of the layer (C) constituting the present invention is preferably 1 to 20 μm, more preferably 5 to 15 μm, and most preferably 7 to 12 μm because the gas barrier property is excellent.

  The barrier coating agent (d) constituting the present invention is a liquid containing a barrier resin, an inorganic filler and the like, and is not particularly limited as long as the object of the present invention is achieved.

  Examples of such barrier resin include ethylene / vinyl alcohol copolymer, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyester, polyamide, and compositions thereof. Among these, ethylene / vinyl alcohol copolymer and polyvinyl alcohol are preferable because they are excellent in barrier property and handling property.

  As such inorganic fillers, oxides such as silica, diatomaceous earth, alumina, iron oxide, hydroxides such as calcium hydroxide and magnesium hydroxide, carbonates such as calcium carbonate and hydrotalcite, sulfuric acid such as calcium sulfate Examples thereof include salts, calcium silicates, clays, micas, silicates such as montmorillonite, nitrides such as aluminum nitride, and carbons such as graphite.

  Further, the shape of the inorganic filler is not particularly limited, and fibrous, spherical, plate-like, needle-like, granular, layered and the like are exemplified. However, it is preferable to use layered inorganic filler because it has excellent gas barrier properties.

  For example, as a commercially available barrier coating agent (d), “Ecostage GB7” manufactured by Sakata Inx Co., Ltd., “LG-OX barrier agent” manufactured by Tokyo Ink Co., Ltd. And Mitsubishi Gas Chemical Co., Ltd. “Maxeeve M-100”.

  Although the thickness of the layer (D) comprising such a barrier coating agent (d) is not particularly limited as long as the object of the present invention is achieved, it is excellent in handling property, gas barrier property and economic efficiency. It is preferable that it is 0.2 to 2.0 μm, more preferably 0.2 to 1.0 μm, and most preferably 0.4 to 0.8 μm.

  The thickness before foaming of the layer (B) constituting the laminate of the present invention is not particularly limited as long as the object of the present invention is achieved, but it is excellent in foamability and has few problems such as breakage. The thickness is preferably 100 to 100 μm, and in the light of economy, the range of 20 to 50 μm is most preferable.

  The thickness of the layer (A) is not particularly limited as long as the object of the present invention is achieved, but is preferably in the range of 60 to 150 μm, more preferably 80 to 120 μm, and still more preferably , 80 to 100 μm.

Although there is no limitation in particular about the paper base material which constitutes the layered product of the present invention, since the foaming ratio of high pressure method low density polyethylene (b) can be improved, the basis weight of a paper base is 150-400 g / m. ² is preferable, More preferably, it is 250-350 g / m < ² >.

The water content of such a paper base is not particularly limited, but is preferably 20 to 40 g / m ² , and more preferably, because the expansion ratio of high-pressure low density polyethylene (b) is improved. It is 20-35 g / m < ² >.

  As a method of obtaining the laminate of the present invention, a paper base material is extrusion laminated with polyethylene resin (a), high-pressure low density polyethylene (b) and polyethylene resin (c), and barrier coating agent (d) is obtained. After coating, a method to be obtained by heating and foaming, (B) a foam to be a layer is adhered to paper, and a polyethylene resin (a) and a polyethylene resin (c) are extrusion laminated to form a barrier coating The method etc. which are obtained by coating an agent (d) can be illustrated. Since processing is easy, the polyethylene resin (a) is laminated, and the high-pressure low density polyethylene (b) and the polyethylene resin (c) are coextrusion laminated to form a barrier coating agent (d). After processing, a method obtained by heating and foaming is preferable.

  Various extrusion laminating methods, such as a single laminating method, a tandem laminating method, a sandwich laminating method, and a coextrusion laminating method, can be exemplified as a method of obtaining a laminate by the extrusion laminating method. The temperature of the resin in the extrusion laminating method is preferably in the range of 260 to 350 ° C., and the surface temperature of the cooling roll is preferably in the range of 10 to 50 ° C.

Also, in extrusion lamination processing, immediately after the polyethylene resin is made into an extruded layer in a molten state, the substrate adhesion surface of the layer is exposed to an oxygen-containing gas or an ozone-containing gas, and the method of bonding to the substrate is used. It is preferable because it is excellent in adhesiveness with the material layer. When the adhesiveness between the thermoplastic resin and the substrate is improved by the ozone-containing gas, the amount of ozone gas to be treated is 0.5 mg or more of ozone per 1 m ^{2 of} film made of thermoplastic resin extruded from a die. Spraying is preferred.

  The extrusion lamination method in the method of obtaining the laminate of the present invention by heating foaming further improves the adhesion between the thermoplastic resin layer and the base layer, so that the temperature at which the polyethylene resin does not foam, for example 30 ° C. It can be heat-treated at a temperature of -60 ° C for 10 hours or more. If necessary, the adhesive surface of the paper substrate may be subjected to known surface treatment such as corona treatment, flame treatment, plasma treatment and the like. In addition, if necessary, an anchor coating agent may be applied to the paper substrate.

  The method for applying such a barrier coating agent (d) is not particularly limited as long as the object of the present invention is achieved, and a gravure coating device, a bar coating device, a doctor coating device, a roll coating device, a blade coating The method using an apparatus, a knife coat apparatus, etc. can be illustrated.

  As a method of obtaining the foam laminate of the present invention, water is applied to one side or both sides of the paper substrate before laminating the polyethylene resin and the paper substrate layer, because the heat insulation and economy of the foam laminate are excellent. You may

  The method of applying the water is not particularly limited as long as the object of the present invention is achieved, and a method using a roll coating device, a lip coating device, a spray device, a die coating device, a gravure device, a dampening device, etc. be able to. A method using a dampening apparatus is preferable because the amount of water applied is uniform.

  Such a dampening apparatus is, for example, a product name "High Rotor S" from Suzuki Sangyo Co., Ltd., a trade name "WEKO Rotor Dampening" from Nikka Co., and a trade name "Tokiki Electronics Co., Ltd." TSD-3000 "is marketed. In particular, it is preferable to use the "High Rotor S" because the application of water is not uneven and the quality is stable.

The application amount of water in the present invention is not particularly limited as long as the object of the present invention is achieved, but the expansion ratio of high-pressure low density polyethylene (b) can be increased, and a paper base and polyethylene resin ( a) and / or ² to 30 g / m ² or less is preferable, and ^{2 to} 10 g / m ² or less is more preferable because adhesion strength with the high pressure low density polyethylene (b) does not decrease.

  The heat source for heating in the method of obtaining the laminate of the present invention by heating foaming is not particularly limited as long as the object is achieved, and examples of laminates and molded containers include hot air, electric heat, electron beams, etc. In the case of a body-shaped container, it can be exemplified that a high temperature object is contained to utilize the heat of the filling. In addition, the heating method can be performed by a method performed batchwise in an oven, a method performed continuously by a conveyor, or the like.

Furthermore, conditions such as heating temperature and heating time are not particularly limited as long as the object of the present invention is achieved, and generally, when hot air is used as a heat source, the heating temperature is high pressure low density polyethylene (b) The melting point is 150 ° C. or less, the air volume is 0.5 to 2.0 m ³ / hour, and the heating time is 10 seconds to 6 minutes.

As such heating conditions, in order to be excellent in heat insulation, it is preferable that the reduction rate constant k (minute ⁻¹ ) of water satisfy the condition of 0.60 to 1.30, and more preferably 0.65 to 1.1. 30, most preferably 0.80 to 1.10.

The decrease rate constant k (minute ⁻¹ ) of water is the amount of change in water dW / dt per unit time at a given heating time t (minute) in the step of foaming high-pressure low density polyethylene (b). It is a proportionality constant in the first order velocity equation represented by the following equation (1) which is a relational expression with the water concentration W in the paper base material at the heating time t (minute).

dW / dt = -kW (1)
Specifically, the reduction rate constant k (min ⁻¹ ) of water is laminated in the order of paper base / polyethylene resin, the density of the polyethylene resin is 940 kg / m ³ , and the thickness of the polyethylene resin is 40 μm. It can be determined using a change in weight upon heating of a certain laminate. Derived from the weight reduction amount ΔW _t (g / m ² ) per unit area after heating at a given time t (minute) which is obtained when heat treatment is applied to a laminate made of paper base material / polyethylene resin and the equation (1) The weight loss per unit area ΔW _{t, cal} (g / m ² ) at a given time t (minute) obtained by calculating the following formula (2) Decreasing rate constant k of water (min) so that the total value from 0.5 minutes to 6 minutes of error ε _t at a given time t (min) expressed by ^{Find the -1} ).

ΔW _{t, cal} = W ₀ [1-exp (−kt)] (2)
ε _t = [(ΔW _t −ΔW _{t, cal} ) / ΔW _t ] ² (3)
Here, W ₀ is the amount of water per unit area (g / m ² ) of the paper base / polyethylene resin before heating.

  In the laminate of the present invention, the total thickness of the foam layer is preferably 700 μm or more, more preferably 800 μm or more, and most preferably 900 μm or more, because the foam layer is excellent in heat insulation.

  In the laminate of the present invention, at least the layer (A) is disposed adjacent to the paper base layer, and on the other side of the paper base, the layer (B) which is a foam layer adjacent to the paper base The (D) layer is disposed on the outer surface than the (C) layer and the (C) layer adjacent to the (B) layer, and the (C) layer and the (D) layer are adjacent and Also, they do not have to be adjacent to each other. In addition, it may include other components, for example, (E) layer, as well as those consisting only of five components of (A) layer, paper base, (B) layer, (C) layer and (D) layer. . Specifically, (A) layer / paper base / (B) layer / (C) layer / (D) layer, (A) layer / paper base / (B) layer / (C) layer / (A) Layer) / (D) layer, (A) layer / paper substrate / (B) layer / (C) layer / (D) layer / (A) layer, (A) layer / (A) layer / paper substrate / (B) layer / (C) layer / (D) layer, (B) layer / (A) layer / paper base material / (B) layer / (C) layer / (D) layer, (A) layer / Paper base / (B) layer / (C) layer / (D) layer / (B) layer, (C) layer / (A) layer / paper base / (B) layer / (C) layer / (D) ) Layer, (A) layer / paper substrate / (B) layer / (C) layer / (E) layer / (D) layer, (A) layer / paper substrate / (B) layer / (C) layer / (D) layer / (E) layer, (E) layer / (A) layer / paper base / (B) layer / (C) layer / (D) layer, (A) layer / paper base / (( B) layer / (C) layer / (E) layer / (B) layer / (D) layer, (A) layer / paper base (B) layer / (C) layer / (D) layer / (E) layer / (D) layer, (B) layer / (A) layer / paper base material / (B) layer / (C) layer / (( E) layer / (A) layer / (D) layer etc. are illustrated.

  Examples of the layer (E) include a layer formed of a synthetic high molecular weight polymer, a woven fabric, a non-woven fabric, a metal foil, papers, cellophane and the like. For example, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon 6 and nylon 66, high density polyethylene, low density polyethylene, linear low density polyethylene, ethylene-ethyl acrylate copolymer, ethylene- Polyethylene resin such as methacrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ionomer, polypropylene resin, polybutene, acrylic resin, polyvinyl alcohol, polymethylpentene, polyvinyl chloride, The layer etc. which are formed from synthetic high molecular polymers, such as polyvinylidene chloride, a polystyrene, a polycarbonate, a polyurethane, a cellulose resin, etc. are mentioned. Furthermore, these polymer films and sheets may be further subjected to aluminum vapor deposition, alumina vapor deposition, silicon dioxide vapor deposition, and acrylic treatment. Moreover, these polymer films and sheets may be further printed using a urethane-based ink or the like. Examples of the metal foil include aluminum foil and copper foil, and examples of the paper include paperboard such as kraft paper, high-quality paper, stretch paper, glassine paper, cup base paper and printing paper base paper.

  The foam laminate of the present invention is a foam laminate having a large thickness of the foam layer and exhibiting good heat insulation and excellent gas barrier properties.

Hereinafter, the present invention will be described by way of Examples and Comparative Examples, but the present invention is not limited thereto.
(1) Density Density was measured in accordance with JIS K 6922-1 (2011).
(2) Melt mass flow rate (MFR)
MFR was measured in accordance with JIS K6922-1 (2011).
(3) Melting temperature Melting temperature was measured in accordance with JIS K6922-2 (2010).
(4) Heat Foaming A gear-type aging tester (No. 102-SHF-77 manufactured by Yasuda Seiki Seisakusho Co., Ltd.) in which the laminate obtained in the example is cut into 10 cm × 20 cm and cylindrically shaped samples are heated to a predetermined temperature. After leaving it for a predetermined time while applying hot air, it was taken out and cooled to room temperature in air. Moreover, it was set as "HIGH" of the "AGING" button about the air volume at the time of heating.
(5) Moisture content of paper base It measured using the Karl-Fisher method moisture measuring apparatus (Mitsubishi Chemical Co., Ltd. make, brand name CA-05) about the paper base before lamination of polyethylene system resin. The measurement temperature is 165 ° C.
(6) Foamed Layer Thickness The foam obtained according to the example and the laminated laminate before foaming as a blank were sampled, and a cross-sectional photograph was taken with an optical microscope. The thickness of the foam layer was measured from the cross-sectional photograph and measured at five points.
(7) Oxygen Permeability Measured according to JIS K7126 A method using the laminate before foaming obtained in the examples and using a differential pressure type gas permeation tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) .

Example 1
As resin of (A) layer, high-density polyethylene (Made by Tosoh Corp., trade name Petrosen LW 04-1) (A1) having MFR of 7 g / 10 min and density of 940 kg / m ³ , resin of (B) layer As high-pressure low-density polyethylene (Tosoh Corp. trade name Petrocene 212) (B1) having a MFR of 13 g / 10 min, a density of 918 kg / m ³ , and a melting temperature of 107 ° C. As high-pressure low-density polyethylene (Tosoh Corp. trade name Petrocene 205) with a MFR of 3 g / 10 min, a density of 924 kg / m ³ , and a melting temperature of 113 ° C. As Eco stage GB7 (made by Sakata Inc.) (D1) was used.

First, (A1) is supplied to a single-screw extrusion laminator (Musushi Nokikai Co., Ltd. product) having a screw with a diameter of 90 mmφ, extruded from a T-die at a temperature of 320 ° C., and the water content is 24.0 g / m ^2. The extrusion lamination was performed on a paper substrate having an amount of 320 g / m ² so that the take-up speed was 60 m / min, the air gap length was 130 mm, and the thickness was 40 μm. Furthermore, (B1) is supplied to a single-screw extruder (Musushi Nokikai Co., Ltd.) having a screw with a diameter of 90 mmφ, and (C1) is supplied to a single-screw extruder (Mushishinokikai Co., Ltd.) having a screw with a diameter of 65 mmφ, After extruding so that the thickness of (B1) becomes 60 μm and the thickness of (C1) becomes 10 μm at a temperature of 320 ° C., a take-up speed of 60 m / min, and an air gap length of 130 mm, Corona treatment was performed under conditions of minutes / m ² . The resulting laminate was cut into a size of 30 cm × 40 cm and subjected to corona treatment to the surface of the layer (C) to obtain a bar coater No. 6 (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) and laminate (D1) so that the film thickness after drying is 0.5 μm, polyethylene resin (A1), paper base, high-pressure low density polyethylene ( B1), a polyethylene resin (C1) and a barrier coating agent (D1) were laminated in this order to obtain a laminate. The resulting laminate was foamed by heating at 120 ° C. for 5 minutes with an air flow rate of HIGH to obtain a foam laminate. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 1.

Example 2
Ethylene / 1-butene copolymer having a MFR of 20 g / 10 min, a density of 936 kg / m ³ , and a melting temperature of 126 ° C. as a polyethylene resin of the layer (C) (manufactured by Tosoh Corp., trade name Niporon-L A laminated body before and after foaming was obtained in the same manner as in Example 1 except that M70) (C2) was used. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 1.

Example 3
Ethylene / 1-butene copolymer having a MFR of 8 g / 10 min, a density of 925 kg / m ³ , and a melting temperature of 123 ° C. as a polyethylene resin of the layer (C) (manufactured by Tosoh Corp., trade name Niporon-L M60) A laminated body before and after foaming was obtained by the same method as in Example 1 except that (C3) was used. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 1.

Example 4
A laminate before and after foaming was obtained in the same manner as in Example 3 except that the layers (B) and (C) were laminated such that the thickness of the layer (B) was 66 μm and the thickness of the layer (C) was 4 μm. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 1.

Example 5
90% by weight of a high density polyethylene (made by Tosoh Co., Ltd., trade name Nipolon Hard 2000) having a MFR of 21 g / 10 min and a density of 952 kg / m ³ as a resin of the layer (A) High-pressure low-density polyethylene (Tosoh Corp. trade name: Petrocene 360) having a density of 919 kg / m ³ is compounded to be 10% by weight, and a single-screw extruder (diameter: 50 mm, manufactured by Plako Co., Ltd.) A laminate before and after foaming was obtained in the same manner as in Example 3, except that the melt-kneaded ethylene-based resin composition (A2, MFR 16 g / 10 min, density 949 kg / m ³ ) was used. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 1.

Example 6
90% by weight of a high density polyethylene (made by Tosoh Co., Ltd., trade name Nipolon Hard 1000) having a MFR of 20 g / 10 min and a density of 966 kg / m ³ as a resin of the layer (A) 90 wt% High-pressure low-density polyethylene (Tosoh Corp. trade name: Petrocene 360) having a density of 919 kg / m ³ is compounded to be 10% by weight, and a single-screw extruder (diameter: 50 mm, manufactured by Plako Co., Ltd.) Laminates before and after foaming were obtained in the same manner as in Example 3 except that melt-kneaded ethylene-based resin composition (A3, MFR 16 g / 10 min, density 961 kg / m ³ ) was used. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 1.

比較例１
（Ｃ）層を積層しなかったこと以外は、実施例１と同様の手法により発泡前後の積層体を得た。得られた発泡前後の積層体について、発泡層の厚み及び酸素透過度を評価した。評価の結果を表２に示す。酸素透過度に劣っていた。

Comparative Example 1
(C) A laminate before and after foaming was obtained in the same manner as in Example 1 except that the layer was not laminated. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 2. It was inferior to the oxygen permeability.

Comparative example 2
A laminate before and after foaming was obtained in the same manner as in Example 5 except that the layer (C) was not laminated. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 2. It was inferior to the oxygen permeability.

Comparative example 3
(C) The laminated body before and behind foaming was obtained by the method similar to Example 6 except not having laminated | stacked the layer. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 2. It was inferior to the oxygen permeability.

Comparative example 4
A laminate before and after foaming was obtained in the same manner as in Example 3 except that the layer (D) was not laminated. The thickness and oxygen permeability of the foam layer were evaluated for the obtained laminate before and after foaming. The results of the evaluation are shown in Table 2. It was inferior to the oxygen permeability.

  The foam laminate of the present invention is suitably used for containers requiring heat insulation, such as paper containers for high-temperature beverages such as coffee and soup, and containers for instant foods such as instant noodles.

Claims (11)

The layer (A) is disposed at least adjacent to the paper substrate layer, and on the other side of the paper substrate, the layer (B) which is a foam layer adjacent to the paper substrate and the layer (B) are adjacent. It is a foam laminate in which the (D) layer is disposed on the outer surface than the (C) layer and the (C) layer, and the density of the (A) layer measured by JIS K 6922-1 (2011) is 925 kg / m ³ or more 970 kg / ^{m 3} or less is polyethylene resin (a), (B) layer pressure was measured density of 910 kg / ^{m 3} or more 930 kg / ^{m 3} or less by the JIS K 6922-1 (2011 years) Method low density polyethylene (b), polyethylene resin (c) whose melting temperature measured according to JIS K 6922-2 (2010) is 6 ° C or more higher than high pressure method low density polyethylene (b), (C) layer (D) layer is a gas barrier coating agent ( d) A foam laminate characterized in that (C) The layer is composed of a polyethylene resin (c) whose melting temperature measured by JIS K 6922-2 (2010) is higher than the high-pressure low density polyethylene (b) by 6 ° C. or more and 19 ° C. or less A foam laminate according to claim 1, characterized in that: The thickness of the (D) layer is 0.2 micrometers or more and 2.0 micrometers or less, The foam laminated body of Claim 1 or 2 characterized by the above-mentioned. Polyethylene resin (a) is, JIS K 6922-1 to claims 1 to 3 any one density measured is equal to or less than 935 kg / ^{m 3} or more 970 kg / ^{m 3} by (2011) Foam laminate as described. Polyethylene resin (a) is, JIS K 6922-1 to claims 1 to 4 any one measured density equal to or less than 945 kg / ^{m 3} or more 970 kg / ^{m 3} by (2011) Foam laminate as described. Polyethylene resin (a) is, JIS K 6922-1 to claims 1 to 5 any one measured density equal to or less than 950 kg / ^{m 3} or more 965 kg / ^{m 3} by (2011) Foam laminate as described. Low-pressure ethylene homopolymer (e) having a density of 935 to 980 kg / m ³ measured by JIS K 6922-1 (2011) and / or JIS K 6922-1 (2011). 10-90% by weight of ethylene / α-olefin copolymer (f) having a density of 935 to 980 kg / m ³ , and 10 to 90% by weight of high pressure low density polyethylene (g) ((e ) and (f) a foam laminate according total in any one of claims 1 to 6, characterized in that an ethylene-based resin composition (h) containing 100 wt%) of (g). Foam laminate according to any one of claims 1 to 7 the basis weight of the paper substrate is characterized in that it is 150 g / ^{m 2} or more 400 g / ^{m 2} or less. The thickness of a (C) layer is 1-20 micrometers, The foam laminated body as described in any one of the Claims 1 thru | or 8 characterized by the above-mentioned. The thickness of a (C) layer is 7 micrometers or more and 12 micrometers or less , The foam laminated body of Claim 9 characterized by the above-mentioned. A container comprising the foam laminate according to any one of claims 1 to 10 .