JP6093975B2 - Method for producing foam laminate and foam laminate - Google Patents

Description

  The present invention relates to a method for producing a foam laminate and the foam laminate.

  Conventionally, as a container having a heat insulating property, a synthetic resin, in particular, a polystyrene foamed one is often used. However, the expanded polystyrene container has drawbacks such as high environmental load at the time of disposal and poor printability, and alternatives to other materials are being studied. Under such circumstances, a container in which corrugated paper is pasted on the outer peripheral surface of the paper cup body to form a heat insulating layer, a container in which a laminate of pulp nonwoven fabric and coated paper is bonded to the outer peripheral surface of the paper cup, etc. Has been developed and used.

  However, each method has a drawback that it is not easy to process and mold, and the cost is high. Therefore, by laminating and heating a low-melting-point thermoplastic synthetic resin film on at least one surface of the moisture-containing base material, the synthetic resin film is foamed into irregularities using the moisture contained in the base material. Has been devised (see, for example, Patent Documents 1 to 3). However, the material thus obtained has a thin foam layer and insufficient heat insulation.

  Further, as a means for obtaining a foam having a thick foam layer, a technique has been proposed in which at least a part of the foam surface is vacuum-sucked to thicken the foam layer of the foam cell (see, for example, Patent Document 4). The container body member and the bottom plate member are composed of a high-melting point thermoplastic synthetic resin film laminated on the inner wall surface of the base material of the container body member and the bottom plate member, and the low melting point heat is applied to the outer wall surface of the base material of the container body member. There has been proposed a heat-insulating paper container in which a plastic synthetic resin film is laminated and the low-melting thermoplastic synthetic resin film is foamed by heat treatment (see, for example, Patent Document 5).

  However, the method of thickening the foamed layer by vacuum suction has a problem that it is inferior in cost performance because a vacuum suction device is necessary and a step of performing vacuum suction is required in the manufacturing process. Moreover, in the heat insulating paper container which has a high melting-point thermoplastic synthetic resin in an inner wall surface, the thickness of the foamed layer was thin and heat insulation was inadequate.

Japanese Patent Publication No. 48-32283 JP-A-57-110439 JP 2001-270571 A JP 2004-58534 A Japanese Patent Laid-Open No. 2007-217024

  The objective of this invention is providing the manufacturing method of a foaming laminated body with a thick foam layer and favorable heat insulation.

  As a result of intensive studies to solve the above problems, the present inventors have found that a foamed laminate produced by a specific method exhibits excellent heat insulation properties, and have completed the present invention.

That is, it is a manufacturing method of the foaming laminated body which has at least (A) layer / paper base material / (B) layer in this order, Comprising: It passes through the process of (i)-(iii) shown below at least. The present invention relates to a method for producing a foam laminate.
(I) Step of applying an organic solvent to one or both sides of a paper substrate (ii) (A) The thermoplastic resin (a) constituting the layer and the thermoplastic resin (b) constituting the layer (B) Step of laminating on material (iii) Step of applying heat treatment to laminate made of thermoplastic resin (a) / paper substrate / thermoplastic resin (b) to foam at least thermoplastic resin (a) It is related with the foaming laminated body manufactured by this method.

  Moreover, it is related with the container which consists of a foaming laminated body manufactured by the method of this invention.

  Hereinafter, the present invention will be described in detail.

  In step (i) of the production method of the present invention, an organic solvent is applied to one side or both sides of the paper base material because the resulting foam laminate is excellent in heat insulation.

  The method of applying the organic solvent is not particularly limited as long as the object of the present invention is achieved, and examples include a method using a roll coater, a lip coater, a spray device, a die coater, a gravure device, a dampening device, and the like. can do. Since the coating amount of the organic solvent becomes uniform, a method using a dampening device is preferable.

  Such a dampening apparatus is, for example, a product name “WEKO rotor dampening” from Nikka Co., Ltd., a product name “High Rotor S” from Suzuki Sangyo Co., Ltd., and a product name “Toko Electronics Co., Ltd.” "TSD-3000" is sold. In particular, it is preferable to use “High Rotor S” because there is no uneven coating of the organic solvent and the quality is stable.

The coating amount of the organic solvent in the present invention is not particularly limited as long as the object of the present invention is achieved, but the expansion ratio of the thermoplastic resin can be increased, and the paper base material and the thermoplastic resin (a) and / or Or since adhesive strength with a thermoplastic resin (b) does not fall, 1.5-30 g / m < ² > is preferable and the range of 15-25 g / m < ² > is more preferable.

  Such an organic solvent is not particularly limited as long as the object of the present invention is achieved, and hydrocarbons such as alkanes, alkenes, alkynes, cycloalkanes, and their halides, alcohols, ketones, aldehydes. Carboxylic acids, esters, ethers, amines, amides, nitriles, aromatics and the like can be exemplified, but alcohols are preferred because of excellent heat insulation.

  Such alcohols are methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, 2-methyl 1-propanol, 2-methyl 2-propanol, 1-pentanol, 2-pentanol, 3 -Monovalent aliphatic alcohols such as pentanol, 2-methyl 1-butanol, 2-methyl 2-butanol, vinyl alcohol, 1-propenol, ethinol, 1-propinol, and divalent aliphatic alcohols such as ethylene glycol and propylene glycol And monovalent alicyclic alcohols such as cyclopropanol, cyclobutanol, cyclopentanol and cyclohexanol, divalent alicyclic alcohols such as cyclopropanediol, aromatic alcohols such as benzyl alcohol, etc. C Excellent Doringu properties, and, since it is excellent in heat insulating property of the foam laminate, monohydric aliphatic alcohols are preferred.

  The boiling point of such an organic solvent is preferably 90 to 110 ° C., more preferably 95 to 105 ° C., because it has excellent heat insulation properties.

  These organic solvents may be used alone or in combination of two or more.

  In step (ii) of the production method of the present invention, the thermoplastic resin (a) and the thermoplastic resin (b) are laminated on both sides of the paper base material.

  The method of laminating the thermoplastic resin (a) and the thermoplastic resin (b) is not particularly limited as long as the object of the present invention is achieved. As a method of molding the laminate of the present invention, an extrusion laminate molding method, Examples thereof include a dry laminate molding method, a wet laminate molding method, a thermal laminate molding method, a hot melt laminate molding method, and a compression molding method. The molding method of the thermoplastic resin (a) and the molding method of the thermoplastic resin (b) may use the same method or different methods.

  Among these molding methods, the extrusion lamination molding method is preferable from the viewpoints of production efficiency and the quality of the molded laminate.

  Examples of the method for obtaining a laminate by an extrusion laminate molding method include various extrusion lamination methods such as a single lamination method, a tandem lamination method, a sandwich lamination method, and a coextrusion lamination 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.

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

  The extrusion laminating method in the method of obtaining the laminate of the present invention by heat foaming further improves the adhesion between the thermoplastic resin layer and the base material layer, so that the temperature at which the thermoplastic resin does not foam, for example, 30-60. Heat treatment can be performed at a temperature of 10 ° C. for 10 hours or more. Moreover, you may perform well-known surface treatments, such as a corona treatment, a flame treatment, and a plasma treatment, with respect to the adhesive surface of a base material as needed. If necessary, an anchor coating agent may be applied to the substrate.

  In the step (iii) of the production method of the present invention, since the heat insulation is excellent, the thermoplastic resin (a) / paper substrate / thermoplastic resin (b) is subjected to heat treatment, and at least the thermoplastic resin (a) is foamed. Let

  The heating method is not particularly limited as long as the object of the present invention is achieved.In addition to hot air, electric heat, and electron beam, the laminate is formed into a container shape, and a high-temperature object is filled in to heat the filling. Arbitrary means such as use can be used. Heating can be performed by a batch method in an oven, a continuous method using a conveyor, or the like.

  Although the heating temperature and the heating time vary depending on the kind of the thermoplastic resin, the heating temperature is generally not lower than the melting point of the thermoplastic resin and not higher than 300 ° C., and the heating time is 10 seconds to 5 minutes.

Although there is no limitation in particular about the paper base material which comprises the laminated body of this invention, since the foaming ratio of a thermoplastic resin can be improved, 150-400 g / m < ² > is preferable for the basic weight of a paper base material, Furthermore, preferably, a 250-350 g / ^{m 2.}

While such no particular limitation on the water contained in the paper substrate, such, since the improved expansion ratio of the thermoplastic resin is preferably from 20 to 30 g / m ^2, more preferably 20~28g / m ² .

  In the production method of the present invention, as long as the object of the present invention is achieved, other steps may be included, and a step of laminating other layers such as paper and thermoplastic resin on the surface of the thermoplastic resin, Examples thereof include a step of printing on a plastic resin or / and paper, a step of boxing the thermoplastic resin (a) / paper base material / thermoplastic resin (b) into a container shape, and the like.

  The thermoplastic resin (a) constituting the laminate of the present invention is not particularly limited as long as the object of the present invention is achieved. Low-density polyethylene, high-density polyethylene, ethylene / 1-butene copolymer, ethylene 1-hexene copolymer, ethylene / 1-octene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid Ethylene polymers such as acid copolymers, ethylene / acrylic acid ester copolymers, ethylene / methacrylic acid ester copolymers, and propylene polymers such as polypropylene, propylene / ethylene copolymers, propylene / 1-butene copolymers Polymers, polyolefins such as poly 1-butene, poly 1-hexene, poly 4-methyl-1-pentene, polyethylene Polyester such as phthalate, polyamide such as nylon 6, polyvinyl alcohol, saponified ethylene / vinyl acetate copolymer, polystyrene, ABS resin, polyvinyl chloride, polymethylmethacrylic acid and other acrylic resins, polyacetal, polycarbonate, polyphenylene sulfide, polyimide Etc. can be illustrated. An ethylene resin, a propylene resin, and polystyrene are preferable because of the excellent thickness of the foamed layer, and an ethylene resin is more preferable because of excellent processability.

  These thermoplastic resins (a) may be used singly or in combination of two or more.

  When mixing a plurality of these thermoplastic resins (a), it may be a pellet mixture in which pellets of a plurality of thermoplastic resins (a) are mixed in a solid state, but a single screw extruder, a twin screw extruder, A mixture obtained by melt-kneading with a kneader, Banbury or the like is preferable because a product with stable quality can be obtained. When using a melt kneader, the melting temperature is preferably about the melting point of the thermoplastic resin to about 300 ° C.

  Further, the thermoplastic resin (a) constituting the laminate of the present invention is generally used for thermoplastic resins such as antioxidants, light stabilizers, antistatic agents, lubricants, antiblocking agents and the like as necessary. Additives may be added as long as the object of the present invention is not impaired.

  The thermoplastic resin (b) constituting the laminate of the present invention is not particularly limited as long as the object of the present invention is achieved. Low-density polyethylene, high-density polyethylene, ethylene / 1-butene copolymer, ethylene 1-hexene copolymer, ethylene / 1-octene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid Ethylene polymers such as acid copolymers, ethylene / acrylic acid ester copolymers, ethylene / methacrylic acid ester copolymers, and propylene polymers such as polypropylene, propylene / ethylene copolymers, propylene / 1-butene copolymers Polymers, polyolefins such as poly 1-butene, poly 1-hexene, poly 4-methyl-1-pentene, polyethylene Polyester such as phthalate, polyamide such as nylon 6, polyvinyl alcohol, saponified ethylene / vinyl acetate copolymer, polystyrene, ABS resin, polyvinyl chloride, polymethylmethacrylic acid and other acrylic resins, polyacetal, polycarbonate, polyphenylene sulfide, polyimide Etc. can be illustrated. An ethylene resin, a propylene resin, and polystyrene are preferable because of the excellent thickness of the foamed layer, and an ethylene resin is more preferable because of excellent processability.

  These thermoplastic resins (b) may be used singly or in combination of two or more.

  When mixing a plurality of these thermoplastic resins (b), a pellet mixture in which pellets of a plurality of thermoplastic resins (b) are mixed in a solid state may be used, but a single screw extruder, a twin screw extruder, A mixture obtained by melt-kneading with a kneader, Banbury or the like is preferable because a product with stable quality can be obtained. When using a melt kneader, the melting temperature is preferably about the melting point of the thermoplastic resin to about 300 ° C.

  Further, the thermoplastic resin (b) constituting the laminate of the present invention is generally used for thermoplastic resins such as antioxidants, light stabilizers, antistatic agents, lubricants, antiblocking agents and the like as necessary. Additives may be added as long as the object of the present invention is not impaired.

Among the thermoplastic resins constituting the laminate of the present invention, since the thickness and workability of the foamed layer are excellent, at least the thermoplastic resin (a) has a density (hereinafter referred to as JIS K6922-1 (1997)). A high pressure method low density polyethylene (c) having a density of 915 to 930 kg / m ³ is preferred. Since it is excellent in foam layer thickness, it is more preferable if it is in the range of 910 to 925 kg / m ³ .

  Such a high pressure method low density polyethylene (c) can be obtained by a conventionally known high pressure method radical polymerization method.

  Further, 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 (c) is 6 to 30 g / 10 min. Is more preferable, more preferably 8 to 30 g / 10 minutes, still more preferably 10 to 24 g / 10 minutes, and most preferably 13 to 18 g / 10 minutes.

  You may mix | blend other polyolefins, such as an ethylene-alpha-olefin copolymer, with the high pressure method low density polyethylene (c) which comprises this invention.

  When the polyolefin is mixed with the high pressure method low density polyethylene (c) constituting the laminate of the present invention, the pellet mixture may be a mixture of pellets of the high pressure method low density polyethylene (c) and polyolefin pellets in a solid state. Although a mixture obtained by melt-kneading with a single screw extruder, twin screw extruder, kneader, Banbury or the like is preferable, a product with stable quality can be obtained. When using a melt kneader, the melting temperature is preferably about the melting point of the polyolefin resin to about 300 ° C.

  In addition, the high-pressure low-density polyethylene (c) 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, and an antiblocking agent 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, the thermoplastic resin (b) constituting the laminate of the present invention is preferably a polyethylene resin (d) having a density of 935 to 970 kg / m ³ , because it is excellent in heat insulation and foaming stability, More preferably, it is 945-970 kg / m < ³ >, Most preferably, it is 950-965 kg / m < ³ >.

  As the polyethylene resin (d) constituting the laminate of the present invention, an ethylene homopolymer, an ethylene / α-olefin copolymer, or a composition thereof can be used. It may be a chain or may have a long chain branch having 6 or more carbon atoms. Such polyethylene resin (d) is not particularly limited.

  Examples of such ethylene homopolymers include low pressure ethylene homopolymers and high pressure low density polyethylene.

  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, 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 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.

  Such a low-pressure ethylene homopolymer can be obtained by a conventionally known low-pressure ion polymerization method.

  Such a high pressure method low density polyethylene can be obtained by a conventionally known high pressure radical polymerization method.

  Among these, since the laminate moldability is excellent, the high-density polyethylene (e) 10 to 90% by weight and the high-pressure method low-density polyethylene (f) 90 to 10% by weight (the total of (e) and (f) is 100). It is preferable that it is an ethylene resin composition (g) containing (weight%).

  Examples of the high density polyethylene (e) include a low-pressure ethylene homopolymer and an ethylene / α-olefin copolymer.

  Moreover, in high density polyethylene (e), since it is excellent in the laminate processability of an ethylene-type resin composition (g), MFR has the preferable range of 6-100 g / 10min, More preferably, it is 8-60 g / 10min. It is a range.

Furthermore, in the high density polyethylene (e), the density of the ethylene resin composition (g) is preferably in the range of 935 to 980 kg / m ³ , more preferably 945 to 975 kg / m in order to be excellent in laminate processability and productivity. ³ range.

  The high pressure method low density polyethylene (f) can be obtained by a conventionally known high pressure radical polymerization method.

  Further, in the high-pressure method low-density polyethylene (f), since the extrusion processability of the ethylene-based resin composition (g) is excellent, the MFR is preferably in the range of 0.1 to 20 g / 10 minutes, more preferably 0.3. It is in the range of -10 g / 10 min, most preferably 1-4 g / 10 min.

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

  The MFR of such an ethylene resin composition (g) is preferably in the range of 1 to 50 g / 10 minutes, and more preferably in the range of 3 to 20 g / 10 minutes because of excellent laminate moldability.

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

  When the polyolefin is mixed with the polyethylene resin (d) constituting the laminate of the present invention, a pellet mixture in which the pellets of the polyethylene resin (d) and the polyolefin pellets are mixed in a solid state may be used. A mixture obtained by melt kneading with a screw extruder, twin screw extruder, 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 polyethylene resin to about 300 ° C.

  Furthermore, the polyethylene-based resin (d) constituting the present invention includes additives generally used for polyolefin resins, such as an antioxidant, a light stabilizer, an antistatic agent, a lubricant, and an antiblocking agent, as necessary. May be added as long as the object of the present invention is not impaired.

  The thickness before foaming of the layer (A) constituting the laminate of the present invention is not particularly limited as long as the object of the present invention is achieved, but is 30 μm because it has excellent foaming properties and less problems such as breakage. The thickness is preferably ˜5 mm, and is preferably 60 to 200 μm, and most preferably 80 to 150 μm, since the foam appearance is excellent.

  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 is 30 μm because it has excellent foaming properties and small problems such as breakage. The thickness is preferably ˜5 mm, and the range of 30 to 150 μm is most suitable from the viewpoint of economy.

  For the laminate of the present invention, the total thickness of the foamed layer is preferably 900 μm or more, more preferably 1000 μm or more, and most preferably 1100 μm or more in order to have excellent heat insulation.

  The laminate of the present invention is characterized in that at least (A) layer / paper base material / (B) layer is laminated, and (A) layer, paper base material, and (B) layer are formed of this layer. They are adjacent in order. (A) A layer, a paper base material, and the (B) layer may contain not only what consists only of 3 components but the other component, for example, (C) layer. Specifically, (A) layer / paper substrate / (B) layer, (A) layer / paper substrate / (B) layer / (A) layer, (B) layer / paper substrate / (A) Layer / (B) layer, (A) layer / paper substrate / (B) layer / (B) layer, (A) layer / (A) layer / paper substrate / (B) layer, (A) layer / Paper substrate / (B) layer / (C) layer, (B) layer / paper substrate / (A) layer / (C) layer, (C) layer / (B) layer / paper substrate / (A) Layer / (B) layer / (C) layer, (A) layer / paper substrate / (B) layer / (C) layer / (B) layer / (A) layer, (B) layer / paper substrate / Examples include (A) layer / (C) layer / (A) layer / (B) layer.

  Examples of the layer (C) include layers formed from synthetic polymer, woven fabric, non-woven fabric, 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- Methacrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyethylene resin such as ionomer, polypropylene resin, polybutene, acrylic resin, polyvinyl alcohol, polymethylpentene, polyvinyl chloride, Examples thereof include a layer formed from a synthetic polymer such as polyvinylidene chloride, polystyrene, polycarbonate, polyurethane, and cellulose resin. Further, these polymer films and sheets may be further subjected to aluminum vapor deposition, alumina vapor deposition, silicon dioxide vapor deposition, or acrylic treatment. Further, these polymer films and sheets may be further printed using urethane ink or the like. Examples of the metal foil include aluminum foil and copper foil, and examples of paper include kraft paper, fine paper, stretched paper, glassine paper, paperboard such as base paper for cups and photographic paper.

  The container of the present invention is composed of at least a trunk member and a bottom member punched to a predetermined size, and is excellent in heat insulation. Therefore, the foamed laminate produced by the production method of the present invention is used for at least the trunk member. Is preferred. There is no particular limitation on the method for producing the container as long as the object of the present invention is achieved.

  Moreover, although the order of the process of boxing a container is not particularly limited, it is preferably performed between the process (ii) and the process (iii) because of high production efficiency.

  By the production method of the present invention, a foamed laminate having a large foam layer and good heat insulation can be produced.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to these.
(1) Density Density was measured according to JIS K6922-1 (1997).
(2) Melt mass flow rate (MFR)
MFR was measured according to JIS K6922-1 (1997).
(3) Heat-foaming Gear-type aging tester (No. 102-SHF-77 manufactured by Yasuda Seiki Seisakusho Co., Ltd.) obtained by heating a sample obtained by cutting out the laminate obtained in Examples into 10 cm × 20 cm and forming it into a cylindrical shape at 120 ° C. The mixture was allowed to stand in the inside for a predetermined time, then taken out and cooled in air to room temperature.
(4) Water content of paper base material The paper base material before lamination of the polyethylene resin was measured by using a Karl Fischer method water measuring device (trade name CA-05, manufactured by Mitsubishi Chemical Corporation). The measurement temperature is 165 ° C.
(5) Foam Layer Thickness Samples were taken of the foam obtained in the examples and the laminate laminate before foaming as a blank, 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 locations. When the thickness of the foamed layer was less than 900 μm, it was evaluated as “x”, when it was 900 μm or more and less than 1000 μm, Δ, and when it was 1000 μm or more and less than 1100 μm, it was rated as “good”. In addition, it evaluated that it was favorable if the foamed layer thickness was 1000 micrometers or more.
(6) State of foam surface The smoothness of the surface of the obtained foam was visually observed. The case where the smoothness of the surface was good was marked with ◯, the case where it was good but slightly inferior was marked with Δ, and the case where it was poor was marked with ×.
(7) Adhesive strength with paper substrate About the laminate obtained by the examples, the adhesive strength between the paper substrate and polyethylene resin was measured using Autograph DCS-100 (manufactured by Shimadzu Corporation). did. The tensile speed was 300 mm / min, the distance between chucks was 50 mm, and the length and width of the test piece were 70 mm and 15 mm, respectively. When the adhesive strength was less than 5 N / 15 mm, it was evaluated as x when the adhesive strength was 5 N / 15 mm or more and less than 6 N / 15 mm, and when it was 6 N / 15 mm or more. In addition, it evaluated that it was favorable if adhesive strength with a paper base material was 5 N / 15mm or more.

Example 1
As the thermoplastic resin (a), a high-pressure low-density polyethylene (trade name Petrocene 212 manufactured by Tosoh Corporation) (A1) having an MFR of 13 g / 10 min and a density of 919 kg / m ³ is used as the thermoplastic resin (b). As an organic solvent, high-density polyethylene (trade name Petrocene LW04-1 manufactured by Tosoh Corporation) (B1) having an MFR of 7 g / 10 min and a density of 940 kg / m ³ is a hydrocarbon and has a boiling point. Normal heptane (S1) at 99 ° C. was used.

First, a paper substrate having a water content of 24 g / m ² and a basis weight of 320 g / m ² using a high rotor S (manufactured by Suzuki Sangyo Co., Ltd.) on the surface of the paper substrate on which (A1) is laminated. 10 g / m ² of (S1) was applied to the substrate, and (A1) was supplied to a single-screw extrusion laminator (manufactured by Musashinokikai Co., Ltd.) having a screw with a diameter of 90 mmφ and extruded from a T-die at a temperature of 320 ° C. Extrusion lamination was performed on the substrate so that the take-up speed was 60 m / min, the air gap length was 130 mm, and the thickness was 70 μm. Further, (B1) was supplied to a single screw extruder (Musashi Nokikai Co., Ltd.) having a screw with a diameter of 90 mmφ, a temperature of 320 ° C., a take-up speed of 60 m / min, an air gap length of 130 mm, 70 μm Extrusion laminating was performed to obtain a thickness, and a laminate obtained by laminating a high-pressure method low-density polyethylene (A1), a paper base material, and a high-density polyethylene (B1) in this order was obtained. The obtained laminate was heated and foamed at 120 ° C. for 5 minutes to obtain a foam laminate. About the obtained laminated body before and behind foaming, the thickness of the foamed layer and the adhesive strength with the paper substrate were evaluated. The evaluation results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 2
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was a ketone and diethyl ketone (S2) having a boiling point of 101 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 3
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was pentanal (S3) which was an aldehyde and had a boiling point of 103 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 4
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper substrate was carboxylic acids and formic acid (S4) having a boiling point of 101 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 5
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper substrate was normal propyl acetate (S5) having an ester and a boiling point of 102 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 6
A laminate before and after foaming was obtained by the same method as in Example 1 except that the organic solvent applied to the paper base material was ethers and 1,4-dioxane (S6) having a boiling point of 101 ° C. . About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 7
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was amines and butylethylamine (S7) having a boiling point of 108 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 8
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was nitriles and propylnitrile (S8) having a boiling point of 97 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 9
A laminated body before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was toluene (S9) which is an aromatic and has a boiling point of 111 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 10
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was alcohol, and 2-butanol (S10) having a boiling point of 100 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 1. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

実施例１１
紙基材に塗布した有機溶剤を、アルコール類であり、沸点が１０８℃であるイソブチルアルコール（Ｓ１１）とした以外は、実施例１と同様の手法により発泡前後の積層体を得た。得られた積層体について、発泡層の厚み、紙基材との接着強度を評価した。結果を表２に示す。発泡後の発泡層の厚み、発泡表面の平滑性、紙基材との接着強度はともに良好であった。

Example 11
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was alcohols and the isobutyl alcohol (S11) having a boiling point of 108 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 2. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 12
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was alcohol and 1-butanol (S12) having a boiling point of 117 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 2. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 13
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was alcohol and isopropanol (S13) having a boiling point of 83 ° C. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 2. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 14
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent applied to the paper base material was alcohol and the boiling point was 91 ° C. cyclopropanol (S14). About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 2. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

実施例１５
紙基材における（Ａ１）を積層する面に１ｇ／ｍ^２の（Ｓ１０）を塗布した以外は、実施例１０と同様の手法により発泡前後の積層体を得た。得られた積層体について、発泡層の厚み、紙基材との接着強度を評価した。結果を表３に示す。発泡後の発泡層の厚み、発泡表面の平滑性、紙基材との接着強度はともに良好であった。

Example 15
A laminate before and after foaming was obtained in the same manner as in Example 10 except that 1 g / m ² of (S10) was applied to the surface of the paper substrate on which (A1) was laminated. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 3. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 16
A laminate before and after foaming was obtained in the same manner as in Example 10 except that ² g / m ² of (S10) was applied to the surface of the paper substrate on which (A1) was laminated. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 3. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.
Example 17
A laminate before and after foaming was obtained in the same manner as in Example 10 except that 20 g / m ² of (S10) was applied to the surface of the paper base material on which (A1) was laminated. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 3. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 18
A laminate before and after foaming was obtained in the same manner as in Example 10 except that 30 g / m ² of (S10) was applied to the surface of the paper substrate on which (A1) was laminated. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 3. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 19
A laminated body before and after foaming was obtained in the same manner as in Example 10 except that 35 g / m ² of (S10) was applied to the surface of the paper substrate on which (A1) was laminated. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 3. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 20
Example 10 except that 15 g / m ² of (S10) was applied to the surface of the paper substrate on which (A1) was laminated, and 15 g / m ² of (S10) was applied to the surface of (B1) to be laminated. A laminate before and after foaming was obtained by the same method. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 3. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 21
(S10) is not applied to the surface on which (A1) is laminated in the paper substrate, and 30 g / m ² of (S10) is applied to the surface on which (B1) is laminated. A laminate before and after foaming was obtained. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 3. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 22
(B) As a resin for the layer, 90% by weight of high density polyethylene (trade name Nipolon Hard 2000 manufactured by Tosoh Corporation) having an MFR of 21 g / 10 min and a density of 952 kg / m ³ , and MFR of 1.6 g / 10 min The high-pressure low-density polyethylene having a density of 919 kg / m ³ (trade name Petrocene 360 manufactured by Tosoh Corporation) was blended to 10% by weight, and a single-screw extruder (Placo Corporation diameter 50 mm) was used. Laminate molding was carried out in the same manner as in Example 18 except that the melt-kneaded ethylene resin composition (B2, MFR 16 g / 10 min, density 949 kg / m ³ ) was used to obtain a laminate before and after foaming. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 3. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 23
(B) As the resin of the layer, 90% by weight of high density polyethylene (trade name Nipolon Hard 1000 manufactured by Tosoh Corporation) having an MFR of 20 g / 10 min and a density of 966 kg / m ³ , and MFR of 1.6 g / 10 min The high-pressure low-density polyethylene having a density of 919 kg / m ³ (trade name Petrocene 360 manufactured by Tosoh Corporation) was blended to 10% by weight, and a single-screw extruder (Placo Corporation diameter 50 mm) was used. Laminate molding was performed in the same manner as in Example 18 except that the melt-kneaded ethylene resin composition (B3, MFR 16 g / 10 min, density 961 kg / m ³ ) was used, and a laminate before and after foaming was obtained. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 3. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

実施例２４
（Ａ１）の厚みを８０μｍとした以外は、実施例１０と同様の手法により発泡前後の積層体を得た。得られた積層体について、発泡層の厚み、発泡表面の状態、紙基材との接着強度を評価した。評価の結果を表４に示す。発泡後の発泡層の厚み、発泡表面の平滑性、紙基材との接着強度はともに良好であった。

Example 24
A laminate before and after foaming was obtained in the same manner as in Example 10 except that the thickness of (A1) was 80 μm. About the obtained laminated body, the thickness of the foam layer, the state of the foam surface, and the adhesive strength with a paper base material were evaluated. Table 4 shows the evaluation results. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 25
A laminate before and after foaming was obtained in the same manner as in Example 17 except that the thickness of (A1) was 80 μm. About the obtained laminated body, the thickness of the foam layer, the state of the foam surface, and the adhesive strength with a paper base material were evaluated. Table 4 shows the evaluation results. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 26
A laminated body before and after foaming was obtained in the same manner as in Example 18 except that the thickness of (A1) was 80 μm. About the obtained laminated body, the thickness of the foam layer, the state of the foam surface, and the adhesive strength with a paper base material were evaluated. Table 4 shows the evaluation results. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 27
A laminate before and after foaming was obtained in the same manner as in Example 18 except that the thickness of (A1) was 100 μm. About the obtained laminated body, the thickness of the foam layer, the state of the foam surface, and the adhesive strength with a paper base material were evaluated. Table 4 shows the evaluation results. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 28
A laminate before and after foaming was obtained by the same method as in Example 18 except that the thickness of (A1) was 120 μm. About the obtained laminated body, the thickness of the foam layer, the state of the foam surface, and the adhesive strength with a paper base material were evaluated. Table 4 shows the evaluation results. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 29
A laminate before and after foaming was obtained by the same method as in Example 18 except that the thickness of (A1) was 150 μm. About the obtained laminated body, the thickness of the foam layer, the state of the foam surface, and the adhesive strength with a paper base material were evaluated. Table 4 shows the evaluation results. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

Example 30
A laminated body before and after foaming was obtained in the same manner as in Example 23 except that the thickness of (A1) was 100 μm. About the obtained laminated body, the thickness of the foam layer, the state of the foam surface, and the adhesive strength with a paper base material were evaluated. Table 4 shows the evaluation results. The thickness of the foamed layer after foaming, the smoothness of the foamed surface, and the adhesive strength with the paper substrate were all good.

比較例１
紙基材に有機溶剤を塗布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。得られた積層体について、発泡層の厚み、紙基材との接着強度を評価した。結果を表５に示す。発泡表面の平滑性及び紙基材との接着強度は良好であったものの、発泡後の発泡層の厚みに劣っていた。

Comparative Example 1
A laminate before and after foaming was obtained in the same manner as in Example 1 except that the organic solvent was not applied to the paper substrate. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 5. Although the smoothness of the foamed surface and the adhesive strength with the paper substrate were good, the thickness of the foamed layer after foaming was inferior.

Comparative Example 2
A laminate before and after foaming was obtained in the same manner as in Example 22 except that the organic solvent was not applied to the paper base material. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 5. Although the smoothness of the foamed surface and the adhesive strength with the paper substrate were good, the thickness of the foamed layer after foaming was inferior.

Comparative Example 3
A laminate before and after foaming was obtained in the same manner as in Example 23 except that the organic solvent was not applied to the paper substrate. About the obtained laminated body, the thickness of the foam layer and the adhesive strength with a paper base material were evaluated. The results are shown in Table 5. Although the smoothness of the foamed surface and the adhesive strength with the paper substrate were good, the thickness of the foamed layer after foaming was inferior.

  The foamed laminate of the present invention is suitably used for containers that require 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 (10)

A method for producing a foam laminate having at least (A) layer / paper substrate / (B) layer in this order, wherein the laminate is subjected to at least the following steps (i) to (iii): Body manufacturing method.
(I) A step of applying an organic solvent having a boiling point of 83 ° C. or higher and 117 ° C. or lower on one side or both sides of a paper base material (ii) The thermoplastic resin (a) and the (B) layer constituting the (A) layer are constituted. Step (iii) Laminating Thermoplastic Resin (b) on Paper Substrate (iii) A laminate comprising the thermoplastic resin (a) / paper substrate / thermoplastic resin (b) is subjected to heat treatment, and at least the thermoplastic resin (a ) Foaming process ^{2. The} method for producing a foam laminate according to claim 1, wherein the amount of the organic solvent applied to the paper substrate is 1.5 g / m ² or more and 30 g / m ² or less. An organic solvent is apply | coated to a paper base material using a dampening apparatus, The manufacturing method of the foaming laminated body of Claim 1 or 2 characterized by the above-mentioned. The method for producing a foam laminate according to any one of claims 1 to 3, wherein the boiling point of the organic solvent applied to the paper substrate is 90 ° C or higher and 110 ° C or lower. The method for producing a foam laminate according to any one of claims 1 to 4, wherein the organic solvent applied to the paper substrate is an alcohol. Method for producing a foam laminate according to claim 1, 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 the (A) layer before foaming is 60 micrometers or more and 200 micrometers or less, The manufacturing method of the foaming laminated body in any one of Claims 1-6 characterized by the above-mentioned. The thermoplastic resin (a) is characterized in that it is a JIS K 6922-1 high-pressure measured density of 915 kg / ^{m 3} or more 930 kg / ^{m 3} or less by (1997) low density polyethylene (c) method for producing a foam laminate according to any one of claims 1-7. Claim the thermoplastic resin (b) is the density measured by JIS K 6922-1 (1997 years) is characterized in that it is a 930 kg / ^{m 3} or more 970 kg / ^{m 3} or less is polyethylene resin (d) The manufacturing method of the foaming laminated body in any one of 1-8 . The polyethylene resin (d) contains 10 to 90% by weight of high-density polyethylene (e) and 10 to 90% by weight of high-pressure low-density polyethylene (f) (the total of (e) and (f) is 100% by weight). It is an ethylene-type resin composition (g), The manufacturing method of the foaming laminated body of Claim 9 characterized by the above-mentioned.