Laminate and paper container for liquid

Abstract

To provide a laminate with excellent interlayer adhesiveness and excellent straw piercing characteristics, and a paper container for liquid in which the same is used.SOLUTION: Provided is a laminate 1 including a first polyethylene layer 12 on one of surfaces of a paper base material layer 10 and a multilayer resin layer 24 on the other surface with a first adhesive layer 16 interposed therebetween. The multilayer resin layer 24 has a second polyethylene layer 18 and a third polyethylene layer 20. The second polyethylene layer 18 is composed of mixed resin of high-density polyethylene resin and low-density polyethylene resin. The third polyethylene layer 20 is composed of linear low-density polyethylene resin or mixed resin of linear low-density polyethylene resin and low-density polyethylene resin. Also provided is a paper container for liquid in which this laminate 1 is used.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laminate and a paper container for liquids using the laminate. [Background technology]

[0002] 2. Description of the Related Art Paper containers used for juice, alcoholic beverages, and the like include paper containers having a paper base material on which a polyethylene layer and an aluminum layer are laminated (see Patent Document 1).

[0003] Such paper containers are manufactured by heating and bonding (sealing) a vertical seal panel connected to a body panel made of a paper base material having thermoplastic resin laminated on both sides to the edge of the body panel, to form the cylindrical body of the paper container, and by bonding the upper and lower ends of the body panel together, the top and bottom are sealed to form the paper container (see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-2196 A [Patent Document 2] Patent Publication No. 2021-147101 Summary of the Invention [Problem to be solved by the invention]

[0005] When drinking the beverage liquid in the paper container described in Patent Document 2, a straw is inserted into the straw insertion port provided at the top of the paper container, and the beverage liquid in the paper container is drunk by sucking through the straw. Therefore, the resin layer laminated on the paper base layer is required to have good straw piercing properties. In addition, if the paper base material curls, it becomes difficult to bond the paper base materials together by heating, so the resin layer laminated on the paper base material layer is required to not curl and to have good adhesion between the paper base materials.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a laminate that does not curl, has good adhesion between laminates, and is easy to pierce with a straw, and a paper container for liquids using the same. [Means for solving the problem]

[0007] The present invention has been made to solve the above problems, and has been completed based on the discovery that the problems of the present invention can be solved by using a specific resin as the resin constituting the second polyethylene layer and the third polyethylene layer provided on the other side of the paper base layer. The gist of the present invention is as follows.

[0008] [1] A laminate having a first polyethylene layer on one side of a paper base layer and a multilayer resin layer on the other side via a first adhesive layer, the multilayer resin layer having at least a second polyethylene layer and a third polyethylene layer provided on the opposite side of the second polyethylene layer from the paper base layer, the second polyethylene layer being composed of a mixed resin of a high-density polyethylene resin and a low-density polyethylene resin, the high-density polyethylene resin content being 5% by mass or more and 30% by mass or less with respect to the total resin constituting the second polyethylene layer, the third polyethylene layer being composed of a linear low-density polyethylene resin or a mixed resin of a linear low-density polyethylene resin and a low-density polyethylene resin, the low-density polyethylene resin content being 30% by mass or less with respect to the total resin constituting the third polyethylene layer, and the polyethylene resin constituting the second polyethylene layer having a melt flow rate of 0.2 to 3.0 g / 10 min. [2] The laminate according to [1], wherein the multilayer resin layer is formed by laminating the second polyethylene layer and the third polyethylene layer in contact with each other. [3] The laminate according to [1] or [2], which has a gas barrier layer between the paper base layer and the first adhesive layer. [4] The laminate according to any one of [1] to [3], wherein the first adhesive layer is made of a linear low-density polyethylene resin. [5] The laminate according to [3], wherein the paper base layer and the gas barrier layer are laminated via a second adhesive layer. [6] The laminate described in [5], wherein the second adhesive layer is composed of a linear low-density polyethylene resin. [7] The laminate according to any one of [1] to [6], wherein the multilayer resin layer has heat sealability. [8] The laminate according to any one of [1] to [7], wherein at least one of the first polyethylene layer, the second polyethylene layer, and the third polyethylene layer contains biomass low-density polyethylene and has a biomass degree of 70% or more. [9] The laminate according to any one of [1] to [8], wherein the gas barrier layer contains polyethylene terephthalate as a constituent resin, and the polyethylene terephthalate has an intrinsic viscosity of 0.58 to 0.80 dl / g.

[10] The laminate according to any one of [1] to [9], wherein the polyethylene resin constituting the first polyethylene layer and the third polyethylene layer has a melt flow rate of 0.8 to 10 g / 10 min.

[11] The laminate according to any one of [1] to

[10] , wherein the difference between the melt flow rate of the high-density polyethylene resin of the second polyethylene layer and the melt flow rate of the low-density polyethylene resin is 2.8 g / 10 min or less.

[12] The laminate according to any one of [1] to

[11] , wherein the difference between the melt flow rate of the linear low density polyethylene resin of the third polyethylene layer and the melt flow rate of the low density polyethylene resin is 3 g / 10 min or less.

[13] The basis weight of the paper constituting the paper base layer is 100 to 500 g / m 2 The laminate according to any one of [1] to

[12] ,

[14] A paper container for liquids comprising the laminate according to any one of [1] to

[13] . Effect of the Invention

[0009] According to the present invention, it is possible to provide a laminate which does not curl, has good adhesion between laminates, and has good straw piercing properties, and a paper container for liquids using the same. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a conceptual diagram showing a laminate of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The laminate and paper container for liquid according to the present invention will be described below with reference to the accompanying drawings. Fig. 1 is a conceptual diagram showing the laminate of the present invention.

[0012] [Laminate] The laminate 1 of the present invention has a first polyethylene layer 12 on one side of a paper base layer 10, and a multilayer resin layer 24 on the other side via a first adhesive layer 16. The multilayer body 24 has at least a second polyethylene layer 18 and a third polyethylene layer 20 provided on the side of the second polyethylene layer 18 opposite the paper base layer 10. In the laminate 1 of the present invention, the third polyethylene layer 20 side becomes the inner surface side of a liquid paper container or a packaged product, and the first polyethylene layer 12 side becomes the surface side.

[0013] <Paper base layer> The paper base material constituting the paper base material layer 10 is not particularly limited as long as it does not impair the effects of the present invention, and any known paper base material used for liquid paper containers and packaging products can be used. Specifically, the paper may be any of the following: acidic paper made from pulp or recycled pulp and made at an acidic pH, pseudo-neutral paper made at a pseudo-neutral pH, neutral paper made at a neutral pH, and alkaline paper made at an alkaline pH. Of these, the use of acidic paper is preferred in the present invention for the reason of reducing residual hydrogen peroxide during packaging sterilization.

[0014] The paper base material has a basis weight of 100 to 500 g / m 2 The basis weight is preferably in the range of 100 g / m 2 If the stiffness is more than 500 g / m, the stiffness is sufficient and there is no risk of molding defects. 2If the paper base material is less than 150 g / m2, the stiffness is not too high and molding is easy. 2 More preferably, the range is 200 to 300 g / m 2 It is more preferable that the range is .

[0015] <First polyethylene layer> The laminate 1 of the present invention has a first polyethylene layer 12 on one surface (front side) of a paper base layer 10. The first polyethylene layer 12 may be polyethylene derived from fossil fuels, polyethylene derived from biomass, or a mixture of these.

[0016] In the production of biomass-derived ethylene, it is preferable to use biomass-derived fermented ethanol obtained from a plant raw material as a raw material. Examples of plant raw materials include, but are not limited to, corn, sugarcane, and beet. In addition, the method for polymerizing a monomer containing biomass-derived ethylene is not particularly limited, and can be carried out by a known method.

[0017] The polyethylene constituting the first polyethylene layer 12 preferably contains low density polyethylene (LDPE) with a biomass ratio of 70% or more. With a biomass ratio of 70% or more, the amount of fossil fuel used can be significantly reduced, and the environmental load can be reduced to fully meet the needs of global warming countermeasures and the creation of a recycling-oriented society. From the above viewpoints, the biomass ratio is more preferably 80% or more, even more preferably 90% or more, and may be 100%.

[0018] In addition, when there is an odor originating from the biomass, it is also preferable to incorporate a deodorant into the biomass polyethylene layer. Examples of the deodorant include porous substances, metal oxides, and chemically adsorbent substances having acidic or basic groups. The biomass content is only included in materials of biological origin. 14 It can be identified by measuring C.

[0019] The thickness of the first polyethylene layer 12 is preferably in the range of 1 to 30 μm. When the thickness of the first polyethylene layer 12 is 1 μm or more, the heat sealability is sufficient, and when it is 30 μm or less, the repulsion is not strong and molding is easy. From the above viewpoints, the thickness of the polyethylene layer is more preferably in the range of 5 to 20 μm, and further preferably in the range of 10 to 15 μm. The melt flow rate (hereinafter sometimes referred to as "MFR") of the first polyethylene layer 12 is preferably 0.8 to 10 g / 10 min. When the MFR is in this range, sufficient strength and good film formability can be obtained. The melt flow rate can be measured in accordance with ASTM D1238, and the value measured at a measurement temperature of 190° C. and a measurement load of 2.16 kg is used in this embodiment. The same applies hereinafter.

[0020] <Gas barrier layer> The laminate 1 of the present invention preferably has a gas barrier layer 14 on the side of the paper base layer 10 opposite to the first polyethylene layer 12. The gas barrier layer 14 is a layer for preventing deterioration of the quality of the contents due to oxidation, etc. As the gas barrier layer 14, a commonly used aluminum foil can be used. From the viewpoint of recycling resources, it is preferable that the gas barrier layer 14 contains polyethylene terephthalate (hereinafter, also referred to as "PET"). By using PET for the gas barrier layer 14, it can be recycled in the same way as milk cartons and the like.

[0021] Furthermore, by including recycled PET as the PET material, it is possible to make the laminate more environmentally friendly. As for PET, a mixture of recycled PET and virgin PET can be used, and the content of recycled PET is preferably 5% or more, more preferably 80% or more, from the viewpoint of environmental friendliness, and may be 100% recycled PET.

[0022] In the laminate 1 of the present invention, a known vapor-deposited film in which aluminum oxide and / or silicon oxide are vapor-deposited on one side of a film substrate made of PET can also be used as the gas barrier layer 14. In particular, a vapor-deposited film in which aluminum oxide and silicon oxide are two-dimensionally vapor-deposited is preferred. Such a vapor-deposited film has high gas barrier properties and excellent flex resistance. The deposition method is not particularly limited, and may be a vacuum deposition method, a sputtering method, a physical deposition method, a chemical deposition method, or the like.

[0023] The thickness of the gas barrier layer 14 is preferably in the range of 1 to 30 μm. If the thickness of the gas barrier layer 14 is 1 μm or more, sufficient barrier properties are obtained, and if it is 30 μm or less, the repulsion is not strong and molding is easy. From the above viewpoints, the thickness of the gas barrier layer is more preferably in the range of 5 to 20 μm, and further preferably in the range of 9 to 15 μm.

[0024] <Second adhesive layer> The gas barrier layer 14 is preferably laminated to the paper base layer 10 via a second adhesive layer 22. The second adhesive layer 22 improves the adhesion between the paper base layer 10 and the gas barrier layer 14, resulting in better gas barrier properties. The type of adhesive constituting the second adhesive layer 22 is not particularly limited as long as it is capable of adhering the paper base layer 10 and the gas barrier layer 14, and the same adhesive as that used for the first adhesive layer 16, which will be described in detail later, may be used. The thickness of the second adhesive layer 22 is preferably in the range of 1 to 40 μm. If the thickness of the second adhesive layer 20 is 1 μm or more, the adhesion between the paper base layer 10 and the gas barrier layer 14 is sufficient and there is no concern about peeling. On the other hand, if it is 40 μm or less, the repulsion is not strong and molding is easy. From the above viewpoints, the thickness of the second adhesive layer 20 is more preferably in the range of 5 to 30 μm, and even more preferably in the range of 10 to 25 μm.

[0025] <Multilayer resin layer> The laminate 1 of the present invention has a multilayer resin layer 24 on the gas barrier layer 14 via a first adhesive layer 16. The multilayer resin layer 24 has at least a second polyethylene layer 18 and a third polyethylene layer 20 provided on the side of the second polyethylene layer 18 opposite the gas barrier layer 14. FIG. 1 shows the multilayer resin layer 24 consisting of two layers, the second polyethylene layer 18 and the third polyethylene layer 20, in which the third polyethylene layer 20 is provided on the outermost surface opposite the gas barrier layer 14, and the second polyethylene layer 18 is provided in contact with the third polyethylene layer 20 and as an inner layer thereof. Since a paper container for liquid is produced using the laminate 1 of the present invention, it is preferable that the multilayer resin layer 24 has heat sealability. The heat sealability is not particularly limited, and for example, there is a method of heating and melting polyethylene by utilizing the action of ultrasonic vibration, high-frequency induction, high-frequency dielectric, or laser light to seal. Of these, ultrasonic heat sealing is preferable because reliable sealing is possible even if the width of the sealed portion of the paper container for liquid is narrowed.

[0026] (Second polyethylene layer) The resin forming the second polyethylene layer 18 constituting the multi-layer resin layer 24 is a mixed resin obtained by mixing a high density polyethylene resin (HDPE: High Density Polyethylene) and a low density polyethylene resin, and the content of the high density polyethylene resin is 5% by mass or more and 30% by mass or less with respect to the total resin constituting the second polyethylene layer 18. If the content of the high density polyethylene resin is less than 5% by mass, the multi-layer resin layer 24 will be largely elongated, and will not break when pierced with a straw, resulting in poor straw piercing properties. If the content of the high density polyethylene resin exceeds 30% by mass, a high temperature will be required for heat sealing, which may result in poor adhesion. The content of the high density polyethylene resin is preferably 10% by mass or more and 30% by mass or less.

[0027] The MFR of the second polyethylene layer 18 is 0.2 to 3.0 g / 10 min. If the MFR is outside this range, sufficient strength cannot be obtained. If the MFR exceeds 3.0 g / 10 min., mixing of the materials constituting the second polyethylene layer 18 may be insufficient.

[0028] The difference in MFR between the high-density polyethylene resin and the low-density polyethylene resin constituting the second polyethylene layer 18 is preferably 2.8 g / 10 min or less, more preferably 2 g / 10 min or less, and even more preferably no difference. By keeping the difference in MFR within the above range, the high-density polyethylene resin and the low-density polyethylene resin can be easily mixed, thereby improving film formability.

[0029] The thickness of the second polyethylene layer 18 is preferably in the range of 5 μm to 20 μm. By setting the thickness of the second polyethylene layer 18 in the above range, curling of the multilayer body 1 can be suppressed, and the liquid paper container can be easily manufactured. In addition, stretching of the second polyethylene layer 18 can be prevented, and therefore the piercing ability of the straw can be improved. The thickness of the second polyethylene layer 18 is more preferably 5 μm to 10 μm.

[0030] The polyethylene constituting the second polyethylene layer 18 may be fossil-derived polyethylene, biomass-derived polyethylene, or a mixture thereof, similar to the first polyethylene layer 12. From the viewpoint of reducing the environmental load sufficient to meet the needs of global warming countermeasures and the establishment of a recycling-oriented society, the biomass ratio is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more, and may be 100%.

[0031] (Third polyethylene layer) As the resin forming the third polyethylene layer 20 constituting the multi-layer resin layer 24, a linear low density polyethylene resin (LLDPE: Linear Low Density Polyethylene) or a mixed resin of a linear low density polyethylene resin and a low density polyethylene resin is used. When a low density polyethylene resin is used, the content is 30% by mass or less with respect to the total resin constituting the third polyethylene layer 20. By including a linear low density polyethylene resin, the heat sealability during the manufacture of a paper container for liquid can be improved, and the paper container for liquid can be easily manufactured. Furthermore, if the content of the low density polyethylene resin exceeds 30% by mass with respect to the total resin, a blocking phenomenon (a phenomenon in which the third polyethylene layers stick together) is likely to occur, making it difficult to manufacture the paper container for liquid. Furthermore, if the content of the low density polyethylene resin exceeds 30% by mass, the multi-layer resin layer 24 becomes easily stretched, and the piercing ability of a straw becomes poor. The content of the low density polyethylene resin is preferably 10% by mass or more and 30% by mass or less.

[0032] The third polyethylene layer 20 preferably has an MFR of 0.8 to 10 g / 10 min. When the MFR is in this range, sufficient strength is obtained and good film formability is obtained.

[0033] When the third polyethylene layer 20 uses a mixed resin of a linear low-density polyethylene resin and a low-density polyethylene resin, the difference in MFR between the linear low-density polyethylene resin and the low-density polyethylene resin is preferably 3 g / 10 min or less, more preferably 2 g / 10 min or less, and even more preferably no difference. By setting the difference in MFR within the above range, the linear low-density polyethylene resin and the low-density polyethylene resin can be easily mixed, thereby improving film formability.

[0034] The thickness of the third polyethylene layer 20 is preferably in the range of 10 μm to 40 μm. By setting the thickness of the third polyethylene layer 20 in the above range, the piercing property of a straw can be improved. In addition, sufficient heat sealability can be achieved and the repulsion is not strong, so that the liquid paper container can be easily formed. The thickness of the third polyethylene layer 20 is more preferably 20 μm to 35 μm, and further preferably 25 μm to 35 μm.

[0035] The polyethylene constituting the third polyethylene layer 20 may be fossil-derived polyethylene, biomass-derived polyethylene, or a mixture thereof, similar to the first polyethylene layer 12 and the second polyethylene layer 18. From the viewpoint of reducing the environmental load sufficient to meet the needs of global warming countermeasures and the establishment of a recycling-oriented society, the biomass ratio is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more, and may be 100%.

[0036] The method for forming the multi-layer resin layer 24 is not particularly limited, and it can be formed, for example, by an inflation method. In the inflation method, a resin composition for forming the second polyethylene layer 18 and a resin composition for forming the third polyethylene layer 20 are separately prepared, and the resin compositions are extruded into a cylindrical film shape from a circular die provided at the end of the extruder using multiple extruders. Air is fed into the film-like resin to inflate it, and it is air-cooled and solidified, and slits are provided on both ends of the film to divide the film, forming the multi-layer resin layer 24. The multi-layer resin layer 24 can be formed by a T-die method. The T-die method is a method in which a resin composition forming the second polyethylene layer 18 and a resin composition forming the third polyethylene layer 20 are extruded from a T-die provided at the front of an extruder, and then quenched and solidified by a cooling roll to form the multi-layer resin layer 24. The formed multilayer resin layer 24 is laminated on the gas barrier layer 14 via a first adhesive layer 16 described below. Moreover, other resin layers such as the first polyethylene layer 12 can be formed by the T-die method.

[0037] Furthermore, the method for forming the multilayer resin layer 24 is not limited to the above-mentioned formation method, and the multilayer resin layer 24 can also be formed by supplying a resin composition for forming the second polyethylene layer 18 onto the gas barrier layer 14 on which the first adhesive layer 16 is provided, forming the second polyethylene layer 18, providing an adhesive layer on the second polyethylene layer 18, supplying a resin composition for forming the third polyethylene layer 20, and forming the third polyethylene layer 20. Furthermore, a film consisting of the second polyethylene layer 18 and a film consisting of the third polyethylene layer 20 can be produced, and the films can be bonded together by heat sealing or with an adhesive layer to form a multilayer resin layer 24, which can then be laminated on the gas barrier layer 16.

[0038] Furthermore, the multi-layer resin layer 24 may be three or more layers as long as the effects of the present invention are not impaired. When the multi-layer resin layer 24 is three or more layers, it is preferable that the surface of the multi-layer resin layer 24 opposite the gas barrier layer be a third polyethylene layer 20, and that the second polyethylene layer 18 be laminated on the inner layer in contact with the third polyethylene layer 20. By making the inner surface side of the paper container for liquids the third polyethylene layer 20 and the second polyethylene layer 18, the paper container for liquids can be made to have good straw pierceability.

[0039] <First adhesive layer> The multilayer resin layer 24 is laminated on the gas barrier layer 14 via the first adhesive layer 16. By using the first adhesive layer 16, the adhesion between the gas barrier layer 14 and the multilayer resin layer 24 is improved, resulting in better gas barrier properties. From the viewpoint of improving adhesion between the gas barrier layer 14 and the multilayer resin layer 24, it is preferable to use a low-density polyethylene resin or a linear low-density polyethylene resin as the first adhesive layer 16, and linear low-density polyethylene resin is particularly preferable. The thickness of the first adhesive layer 16 is preferably in the range of 1 to 30 μm. If the thickness of the first adhesive layer 16 is 1 μm or more, the adhesion between the gas barrier layer 14 and the multilayer resin layer 24 is sufficient. On the other hand, if the thickness is 30 μm or less, the repulsion is not strong and molding is easy. From the above viewpoints, the thickness of the first adhesive layer 16 is more preferably in the range of 3 to 20 μm, and further preferably in the range of 5 to 15 μm.

[0040] [Liquid paper containers] The paper container for liquids of the present invention is formed by using the laminate of the present invention in accordance with a known forming process. For example, the manufacturing process of a paper container for liquids to hold liquid beverages such as milk or juice usually includes the steps of creating a base material, printing, creasing, punching (creating a blank), pasting, filling with contents, and sealing. The shape of the paper container to be formed is not particularly limited, and the paper container may be formed into any shape, such as a substantially conical shape, a cube, or a tetrahedron. By using biomass-derived polyethylene for the first polyethylene layer 12, the second polyethylene layer 18 and the third polyethylene layer 20, the paper container for liquid of the present invention can provide a paper container for liquid that reduces the environmental burden and is fully responsive to the needs of measures against global warming and the creation of a circular society. EXAMPLES

[0041] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0042] (Experimental Example 1) As the resin constituting the second polyethylene layer, a resin composition was produced at the blending ratio shown in Table 2. In addition, as the resin constituting the third polyethylene layer, a resin composition was produced at the blending ratio shown in Table 2. Using these resin compositions, a multilayer film (multilayer resin layer) in which the second polyethylene layer and the third polyethylene layer were laminated was produced by coextrusion. In addition, as Comparative Example 5, a single layer film of 100% LLDPE was produced.

[0043] (Materials used) The resins used in the above experimental examples are shown in Table 1. The MFR in Table 1 is a value measured at a measurement temperature of 190° C. and a measurement load of 2.16 kg in accordance with ASTM D1238. Resin No. C hardly flowed under a load of 2.16 kg. [Table 1]

[0044] The multilayer film produced in Experimental Example 1 was evaluated by the following evaluation method. The straw piercing property was evaluated for the multilayer film, and the curl of the multilayer film was also evaluated. The results are shown in Table 2.

[0045] (Evaluation method) (1) Film curl The film was cut to a size of 30 cm x 30 cm and allowed to stand without application of any external pressure, and the state of curling was evaluated according to the following criteria. A: The film edge is curled up B: The film end is curled up, and the curl is less than 15 cm. C: The film edge is rolled up, and the roll-up is 15cm or more. (2) Straw piercing strength (strength (N), elongation (mm)) The multilayer film produced in Experimental Example 1 was cut and fixed to a film fixing jig. The film fixing jig was placed on the Strograph, and the straw fixing jig was set on the load cell. The position was adjusted so that the straw passed through the hole in the center of the film fixing jig, and the load cell was lowered at 200 mm / min to measure the maximum force [N] (strength) and elongation [mm] when the straw penetrated.

[0046] [Table 2]

[0047] It was confirmed that Examples 1 to 5, in which the second polyethylene layer contained 30 mass% or less HDPE, had less elongation and were easier to pierce with a straw than Comparative Example 2, which contained no HDPE, and Comparative Example 5, which was a single layer of 100% LLDPE. Moreover, it was confirmed that Example 5, in which the third polyethylene layer contained LDPE, was able to further reduce elongation. In Comparative Example 1, in which the second polyethylene layer contained 50% HDPE, the film itself was hard and had poor puncture resistance, and in Comparative Example 3, in which the third polyethylene layer contained 70% LD, the strength was low and film formation was not possible. [Industrial Applicability]

[0048] Since the present invention has good adhesion between laminates and good straw piercing properties, it can be suitably used for paper containers for liquids such as juices and alcoholic beverages. [Explanation of symbols]

[0049] 1. Laminate 10 Paper base layer 12 First polyethylene layer 14 Gas barrier layer 16 First adhesive layer 18 Second polyethylene layer 20 Third polyethylene layer 22 Second adhesive layer 24 Multilayer resin layer

Claims

1. A laminate having a first polyethylene layer on one side of a paper base layer and a multilayer resin layer on the other side via a first adhesive layer, The multilayer resin layer has at least a second polyethylene layer and a third polyethylene layer provided on the opposite side of the second polyethylene layer to the paper base layer, the second polyethylene layer is composed of a mixed resin of a high-density polyethylene resin and a low-density polyethylene resin, and the content of the high-density polyethylene resin is 5% by mass or more and 30% by mass or less with respect to the total resin constituting the second polyethylene layer; the third polyethylene layer is composed of a linear low-density polyethylene resin or a mixed resin of a linear low-density polyethylene resin and a low-density polyethylene resin, and a content of the low-density polyethylene resin is 30% by mass or less with respect to the total resin constituting the third polyethylene layer; A laminate, wherein the melt flow rate of the polyethylene resin constituting the second polyethylene layer is 0.2 to 3.0 g / 10 min.

2. The laminate according to claim 1 , wherein the multi-layer resin layer is laminated such that the second polyethylene layer and the third polyethylene layer are in contact with each other.

3. The laminate according to claim 1 or 2, further comprising a gas barrier layer between the paper substrate layer and the first adhesive layer.

4. The laminate according to claim 1 or 2, wherein the first adhesive layer is constituted by a linear low density polyethylene resin.

5. The laminate according to claim 3 , wherein the paper base layer and the gas barrier layer are laminated via a second adhesive layer.

6. 6. The laminate of claim 5, wherein the second adhesive layer is comprised of a linear low density polyethylene resin.

7. The laminate according to claim 1 or 2, wherein the multi-layer resin layer has heat sealability.

8. 3. The laminate according to claim 1 or 2, wherein at least one of the first polyethylene layer, the second polyethylene layer, and the third polyethylene layer contains biomass low density polyethylene and has a biomass content of 70% or more.

9. The gas barrier layer contains polyethylene terephthalate as a constituent resin, 4. The laminate according to claim 3, wherein the polyethylene terephthalate has an intrinsic viscosity of 0.58 to 0.80 dl / g.

10. 3. The laminate according to claim 1, wherein the melt flow rate of the polyethylene resin constituting the first polyethylene layer and the third polyethylene layer is 0.8 to 10 g / 10 min.

11. 3. The laminate according to claim 1, wherein the difference between the melt flow rate of the high density polyethylene resin of the second polyethylene layer and the melt flow rate of the low density polyethylene resin is 2.8 g / 10 min or less.

12. 3. The laminate according to claim 1, wherein a difference between a melt flow rate of the linear low density polyethylene resin of the third polyethylene layer and a melt flow rate of the low density polyethylene resin is 3 g / 10 min or less.

13. The basis weight of the paper constituting the paper base layer is 100 to 500 g / m ２ The laminate according to claim 1 or 2,

14. A paper container for liquids, comprising the laminate according to claim 1 or 2.

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