Resin laminate, packaging material, and method for producing resin laminate

Abstract

To provide a packaging material having two-stage heat sealability that allows the easy peelability (an easy-to-open state) or the full sealability (a hard-to-open state) to be exhibited selectively.SOLUTION: This invention relates to a resin laminate having heat sealability, the resin laminate including a paper substrate, and a resin mixture layer provided on at least one side of the paper substrate. The resin mixture layer includes a polyolefin resin and a biomass resin. The content of the biomass resin is 10-49 mass% relative to the total mass of the resin mixture layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a resin laminate, a packaging material, and a method for producing a resin laminate. [Background technology]

[0002] Conventionally, various types of packaging containers have been developed. For example, as a packaging container for food, a packaging container is known which is formed by filling a container with food or the like and then heat-sealing a lid material to an opening of the container. Plastic containers and lid materials are often used as materials for constructing such packaging containers.

[0003] For example, Patent Document 1 discloses a three-layer coextruded laminate film in which a resin layer made of a resin composition mainly composed of polybutylene succinate, a resin layer made of a resin composition mainly composed of a polyethylene resin, and a resin layer made of a resin composition mainly composed of a polylactic acid resin are coextruded in that order, and discloses an easy peel sealant in which a resin layer made of a resin composition mainly composed of a polylactic acid resin is used as a sealing layer. Patent Document 2 discloses a sealant film having a resin layer made of a resin blend obtained by mixing a substrate, a polyolefin resin, a hydrolyzable thermoplastic resin, and a compatibilizer. Patent Document 2 lists resin films such as PET, NY, and OPP as substrates to be bonded to the sealant layer.

[0004] In recent years, from the viewpoint of environmental conservation, there is an increasing demand for such packaging containers to be made without plastic. For this reason, it has been considered to change some of the packaging containers from plastic containers to paper containers. For example, Patent Document 3 discloses a laminate having a paper base material and a synthetic resin layer containing biomass resin on at least one side of the paper base material, in which the synthetic resin layer is a kneaded product of biomass resin and synthetic resin, and discloses that this laminate is processed into paper containers such as paper cups and paper squeeze trays. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-320060 A [Patent Document 2] JP 2013-234224 A [Patent Document 3] JP 2008-188812 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a packaging container composed of a main container and a lid material, the lid material having heat sealability is pasted to the opening of the main container to seal it. In this case, the lid material is required to have heat sealability and exhibit excellent sealing. On the other hand, the lid material may be required to be easily opened. For example, when a plurality of types of food are packed separately, there may be a mixture of a part where the lid material and the main container are firmly attached and easy to open, and a part where easy to open is required, and a variety of functions are required for packaging materials that have become more diverse in recent years. In addition, when the contents are packaged in a bag shape (pillow packaging) using a resin laminate having heat sealability, both easy opening and difficult opening may be required.

[0007] Therefore, the inventors have conducted research with the aim of providing a packaging material with two-stage heat sealability that can exhibit either easy opening (easy peelability) or difficult opening (complete peelability) by controlling the heat sealing conditions. [Means for solving the problem]

[0008] As a result of intensive research to solve the above problems, the inventors have found that in a resin laminate having a paper base material and a mixed resin layer, by selecting the resin types that make up the mixed resin layer and setting the blending ratio of each resin type within a predetermined range, it is possible to obtain a packaging material that can exhibit two-stage heat sealability, which exhibits either easy-to-open properties (easy peel property) or difficult-to-open properties (complete peel property). Specifically, the present invention has the following configuration.

[0009] [1] A paper base material and a mixed resin layer provided on at least one side of the paper base material, The mixed resin layer contains a polyolefin resin and a biomass resin, The content of the biomass resin is 10 to 49 mass% based on the total mass of the mixed resin layer, A resin laminate having heat sealability. [2] The resin laminate according to [1], wherein in the mixed resin layer, the polyolefin resin and the biomass resin are mixed approximately uniformly. [3] The resin laminate according to [1] or [2], wherein the biomass resin is at least one selected from the group consisting of polylactic acid, polybutylene succinate, and polyhydroxyalkanoic acid. [4] The resin laminate according to any one of [1] to [3], wherein the polyolefin resin is a plant-derived polyolefin resin. [5] A packaging material comprising the resin laminate described in any one of [1] to [4]. [6] A method for producing the resin laminate according to any one of [1] to [4], A step of melt-mixing a polyolefin resin and a biomass resin to obtain a resin blend; and spreading the resin blend on a paper substrate by a coating method or a melt extrusion method. [7] The method for producing a resin laminate according to [6], wherein the melting temperature in the step of obtaining the resin blend is 180 to 330°C. Effect of the Invention

[0010] According to the present invention, it is possible to obtain a resin laminate capable of exhibiting two-stage heat sealability, that is, either easy opening property (easy peel property) or difficult opening property (complete peel property). [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a cross-sectional view illustrating the configuration of the resin laminate of the present embodiment. [Diagram 2] FIG. 2 is a cross-sectional view illustrating another configuration of the resin laminate of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "~" means a range including the numerical values ​​before and after "~" as the lower and upper limits.

[0013] (Resin laminate) The present invention relates to a resin laminate having heat sealability, which comprises a paper base material and a mixed resin layer provided on at least one side of the paper base material, wherein the mixed resin layer contains a polyolefin resin and a biomass resin, and the content of the biomass resin is 10 to 49% by mass based on the total mass of the mixed resin layer.

[0014] Fig. 1 is a cross-sectional view illustrating the configuration of the resin laminate of this embodiment. As shown in Fig. 1, the resin laminate 100 has a paper substrate 10 and a mixed resin layer 20. An optional layer as described below may be provided between the paper substrate 10 and the mixed resin layer 20, but the mixed resin layer 20 may be provided so as to be in direct contact with the paper substrate 10.

[0015] The resin laminate of the present invention has the above-mentioned structure, and therefore can exhibit two-stage heat sealability. In this specification, the two-stage heat sealability refers to a property in which either easy-to-open property (easy peel property) or difficult-to-open property (complete peel property) is exhibited depending on the heat seal conditions. That is, when heat sealing is performed using a resin laminate having two-stage heat sealability, easy peel property and complete peel property can be used separately depending on the heat seal conditions. For example, when heat sealing is performed using a resin laminate having two-stage heat sealability, if the heat seal temperature is lowered, easy peel property is exhibited, and if the heat seal temperature is raised, complete peel property is exhibited. In addition, when heat sealing is performed using a resin laminate having two-stage heat sealability, heat sealing can be performed so that easy peel property is exhibited in one part, and complete peel property is exhibited in the other part. For example, when heat sealing is performed on a container in which a plurality of types of food are divided and filled, heat sealing can be performed so that easy peel property is exhibited in the first divided part, and complete peel property is exhibited in the second divided part.

[0016] In this specification, when the resin laminate is heat-sealed to an adherend, for example, if the seal strength is less than 7.0 N / 15 mm, it can be determined that there is easy peel property, and if the seal strength is 7.0 N / 15 mm or more, it can be determined that there is complete sealability.

[0017] The resin laminate of the present invention also has excellent moisture resistance and is suitable for applications such as sealing food, medicine, etc. In this specification, the moisture resistance of the resin laminate can be evaluated by the moisture permeability of the resin laminate. More specifically, the resin laminate is set in a moisture permeability measuring device and the moisture permeability is measured under conditions of 40°C and 90% relative humidity. The moisture permeability of the resin laminate under conditions of 40°C and 90% relative humidity is 50 g / m 2 / 24hr or less is preferable, and 40g / m 2 / 24hr or less is more preferable, and 30g / m 2 / 24hr is even more preferred.

[0018] Furthermore, the resin laminate of the present invention has a high biomass ratio and contributes to reducing greenhouse gas emissions. Such a resin laminate can be used as a packaging material with reduced environmental impact. The biomass ratio can be calculated by carrying out a biomass carbon measurement test in accordance with ASTM D 6866 "Standard Test Methods for Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis." The biomass ratio may also be calculated by referring to literature values.

[0019] In addition, the resin laminate of the present invention has excellent biodegradability because it has a paper base material. Furthermore, by blending a biodegradable biomass resin in the mixed resin layer, it is possible to exhibit even better biodegradability.

[0020] The overall thickness of the resin laminate is preferably 20 to 300 μm. By setting the thickness of the resin laminate within the above range, a balance between strength and flexibility can be maintained, making it suitable for packaging applications. Furthermore, the tensile strength of the resin laminate is preferably 2 N / 15 mm or more, more preferably 4 N / 15 mm or more, and even more preferably 6 N / 15 mm or more. By setting the tensile strength of the resin laminate within the above range, breakage during packaging can be suppressed.

[0021] (Paper base material) The paper base material contains pulp. Examples of pulp that can be used in this embodiment include wood pulp, cotton, hemp, waste paper pulp, non-wood pulp, etc. Among them, it is preferable to use wood pulp, and examples of wood pulp include coniferous tree-derived pulp (NKP) and broadleaf tree-derived pulp (LKP). Examples of non-wood pulp include hemp pulp, kenaf pulp, bamboo pulp, etc. The paper base material used in this embodiment contains 90% by mass or more of pulp. Specifically, examples of the paper base material that can be used include fine paper, glassine paper, coated paper, cast-coated paper, and kraft paper.

[0022] Among them, the pulp is preferably softwood-derived pulp (NKP). By using softwood-derived pulp (NKP) as the pulp, the strength of the paper base material can be effectively increased. In addition, when printing is performed on the paper base material, hardwood-derived pulp (LKP) may be used in combination to improve printability.

[0023] The freeness of the pulp is preferably 300mlcsf to 600mlcsf. The freeness of the pulp is the Canadian standard freeness defined in JIS P 8121-2:2 Pulp - Freeness test method - Part 2: Canadian standard freeness method. By setting the freeness of the pulp within the above range, the strength of the paper base material can be effectively increased.

[0024] The basis weight of the paper base material is not particularly limited, but is preferably 15 g / m 2 It is preferable that the thickness is 20 g / m or more. 2 More preferably, it is 30 g / m or more. 2 It is more preferable that the basis weight of the paper base material is 200 g / m or more. 2 It is preferable that the thickness is less than 150 g / m 2 More preferably, it is 100 g / m or less. 2It is more preferable that the basis weight of the paper substrate is less than 100%. The basis weight of the paper substrate is measured in accordance with JIS P 8124:2011. By setting the basis weight of the paper substrate within the above range, the balance between the strength and flexibility of the resin laminate can be maintained. This makes it easier to impart two-stage heat sealability to the resin laminate.

[0025] The thickness of the paper substrate is preferably 20 μm or more, more preferably 25 μm or more, and even more preferably 30 μm or more. The thickness of the paper substrate is preferably 250 μm or less, and more preferably 200 μm or less. It is more preferable that the thickness is 150 μm or less.

[0026] The tear strength, burst strength, water resistance, wet strength, etc. of the paper base material can be appropriately adjusted according to the packaging application, for example, by using pulp type, freeness, basis weight, internal additives (paper strength agents, wet strength agents, rosin size, alkoxyketene dimer, ASA, etc.), etc.

[0027] The paper base material may contain optional components in addition to pulp, such as internal sizing agents, external sizing agents, aluminum sulfate, paper strength agents, wet strength agents, fixing agents, retention aids, defoamers, fillers, colorants, etc.

[0028] (Mixed resin layer) The mixed resin layer contains a polyolefin resin and a biomass resin. In the mixed resin layer, the polyolefin resin and the biomass resin are preferably mixed substantially uniformly. In this specification, when the resin ratios at any 10 points in the mixed resin layer are calculated, if there is no difference of 5 mass% or more in the resin ratios at any 10 points, it can be determined that the polyolefin resin and the biomass resin are substantially uniformly mixed. The resin ratio is determined by infrared spectroscopy, electron microscope observation, or the like.

[0029] Examples of the polyolefin resin include copolymerized polyolefin resins containing 50 mol% or more of structural units derived from polypropylene, polyethylene, propylene, or ethylene. The polyolefin resin may be a plant-derived polyolefin resin. The plant-derived polyolefin resin can be obtained, for example, as follows. First, starch such as corn or potato or plant-derived cellulose is saccharified and then converted into alcohol, and ethylene is synthesized from the alcohol (plant-derived ethylene). Furthermore, propylene is synthesized from plant-derived ethylene (plant-derived propylene), and a polymer is synthesized from monomers such as plant-derived ethylene and plant-derived propylene, thereby obtaining a plant-derived polyolefin resin. In this case, the biomass degree of the resin laminate is further increased, which is preferable. Examples of the plant-derived polyolefin resin include a plant-derived polyethylene resin and a plant-derived polypropylene resin.

[0030] Examples of biomass resins include polylactic acid, polybutylene succinate, polyhydroxyalkanoic acid, microbial polyester, cellulose acetate, polyamide 11, polyamide 610, polyamide 1010, and polyamide 1012. Among them, the biomass resin is preferably at least one selected from the group consisting of polylactic acid, polybutylene succinate, polyhydroxyalkanoic acid, and polyamide 11, and is particularly preferably polylactic acid. It is particularly preferable that the biomass resin is a resin having biodegradability.

[0031] The content of the biomass resin is 10 to 49% by mass with respect to the total mass of the mixed resin layer. The content of the biomass resin may be 10% by mass or more with respect to the total mass of the mixed resin layer, preferably 15% by mass or more, and more preferably 20% by mass or more. The content of the biomass resin may be 49% by mass or less with respect to the total mass of the mixed resin layer, preferably 45% by mass or less, and more preferably 40% by mass or less. By setting the content of the biomass resin in the mixed resin layer within the above range, the moisture resistance of the resin laminate can be more effectively improved while increasing the biomass degree of the resin laminate. Furthermore, by setting the content of the biomass resin in the mixed resin layer within the above range, the resin laminate can exhibit two-stage heat sealability. For example, when heat sealing is performed using the resin laminate, it is possible to selectively use easy peel property and complete peel property, or to selectively use easy peel property and complete peel property partially depending on the heat sealing conditions.

[0032] The mixed resin layer may further contain an optional component in addition to the polyolefin resin and the biomass resin. For example, a compatibilizer can be mentioned as an optional component. For example, the compatibilizer can be hydrogenated styrene butadiene rubber (HSBR), styrene ethylene butylene olefin crystalline block polymer (SEBC), olefin crystalline ethylene butylene olefin block polymer, styrene ethylene butylene styrene block polymer, polyglycerin fatty acid ester synthesized from coconut palm oil, polyethylene glycidyl methacrylate, graft copolymers having a main chain of polyolefin or polycarbonate and a side chain of vinyl polymer, and the like. In addition, for example, commercially available compatibilizers can be Chirabazol manufactured by Taiyo Kagaku, Modiper manufactured by NOF Corp., and Bondfast manufactured by Sumitomo Chemical Co., Ltd. When the mixed resin layer contains a compatibilizer, the content of the compatibilizer is preferably 1% by mass or more, more preferably 3% by mass or more, based on the total mass of the mixed resin layer. The content of the compatibilizer is preferably 10% by mass or less, more preferably 7% by mass or less, based on the total mass of the mixed resin layer. By including the compatibilizer in the mixed resin layer, the uniform dispersion of the polyolefin resin and the biomass resin is further improved, and a resin laminate having excellent heat seal properties and moisture resistance can be easily obtained.

[0033] The basis weight of the mixed resin layer is not particularly limited, but is preferably 5 g / m 2 It is preferable that the thickness is 8 g / m or more. 2 More preferably, it is 12 g / m or more. 2 The mixed resin layer preferably has a basis weight of 40 g / m or more. 2 Preferably, it is 35 g / m or less. 2 More preferably, it is 30 g / m or less. 2 It is more preferable that the basis weight of the mixed resin layer is less than 100%. The basis weight of the mixed resin layer is measured in accordance with JIS P 8124:2011. By setting the basis weight of the mixed resin layer within the above range, it becomes easier to impart two-stage heat sealability to the resin laminate. In addition, by setting the basis weight of the mixed resin layer within the above range, it becomes easier for the resin laminate to exhibit better moisture resistance.

[0034] The thickness of the mixed resin layer is preferably 5 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more. The thickness of the mixed resin layer is preferably 40 μm or less, more preferably 35 μm or less, and even more preferably 30 μm or less.

[0035] Examples of other optional components contained in the mixed resin layer include colorants, ultraviolet absorbing agents, light scattering agents, preservatives, moisture absorbents, antioxidants, and fillers.

[0036] The mixed resin layer is preferably a layer formed by a melt extrusion method. That is, the mixed resin layer is preferably a melt-kneaded resin layer. The mixed resin layer may be a single layer, or may have a layer structure in which two or more layers are laminated. For example, the mixed resin layer may be a layer formed by laminating two or more mixed resin layers in which the resin ratio or the ratio of the optional component is changed.

[0037] (arbitrary layer) The resin laminate may have an optional layer in addition to the paper base material and the mixed resin layer. For example, the resin laminate may have a single resin layer on at least one side of the paper base material. In this case, the resin laminate is preferably a laminate in which the paper base material / single resin layer / mixed resin layer are laminated in this order. The single resin layer is preferably a polyolefin resin layer, and examples of the polyolefin resin constituting the single resin layer include polypropylene, polyethylene, and copolymerized polyolefin resins containing 50 mol% or more of structural units derived from propylene or ethylene. The polyolefin resin constituting the single resin layer may also be a plant-derived polyolefin resin.

[0038] Fig. 2 is a cross-sectional view illustrating the structure of a resin laminate 100 including a single resin layer 30. As shown in Fig. 2, the resin laminate 100 may have a paper base material 10, a single resin layer 30, and a mixed resin layer 20 in this order. The single resin layer 30 may be provided on both sides of the paper base material 10.

[0039] Examples of other optional layers that the resin laminate may have include an inorganic layer, an anchor layer, an adhesive layer, a printed layer, a decorative layer, and a light-shielding layer.

[0040] (Method of manufacturing resin laminate) The present invention also relates to a method for producing the above-mentioned resin laminate. The method for producing the resin laminate includes at least a step of melt-mixing a polyolefin resin and a biomass resin to obtain a resin blend, and a step of spreading the resin blend on a paper substrate by a coating method or a melt extrusion method. Among them, it is preferable to use the melt extrusion method in the step of spreading the resin blend on the paper substrate.

[0041] In the step of obtaining the resin blend, the polyolefin resin and the biomass resin are melt-mixed. The melting temperature at this time is preferably 180° C. or higher, more preferably 200° C. or higher. The melting temperature is preferably 330° C. or lower, more preferably 300° C. or lower, and even more preferably 280° C. or lower.

[0042] Before the step of obtaining the resin blend, a step of dry-blending the polyolefin resin and the biomass resin may be performed. In the dry-blending step, pellets of the polyolefin resin and pellets of the biomass resin are preferably mixed.

[0043] After the step of spreading the resin blend on the paper substrate, a step of pressurizing and cooling is preferably carried out in order to enhance the adhesion between the paper substrate and the mixed resin layer. The cooling temperature in this step is preferably 80° C. or less, more preferably 50° C. or less.

[0044] In addition, in the method for producing a resin laminate, a step of forming another layer on the paper substrate may be provided before the step of spreading the resin blend on the paper substrate, or a step of subjecting the paper substrate to a surface treatment may be provided.

[0045] (Application) The resin laminate of the present invention is a resin laminate having heat sealability, and therefore can be used as a sealant film (heat seal film). The present invention may also relate to a packaging material including the above-mentioned resin laminate. The packaging material may be made of the above-mentioned resin laminate, or may be made by laminating another layer on the above-mentioned resin laminate. The packaging material may also be made by molding the above-mentioned resin laminate.

[0046] The resin laminate of the present invention may also relate to a packaging material used for forming a bag. For example, the resin laminate may be used to package the contents in a bag (pillow packaging) or to package the contents in a caramel shape. The resin laminate may also be used to package the contents by sealing four or three sides. EXAMPLES

[0047] The features of the present invention will be described in more detail below with reference to examples and comparative examples. The materials, amounts used, ratios, processing contents, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the specific examples shown below. In the following, Examples 1 to 7 should be read as Reference Examples 1 to 7, respectively.

[0048] Example 1 The polyolefin resin used was low-density polyethylene (LDPE), Novatec LD LC520 (made by Nippon Polyethylene, MFR 3.6g / 10min (JIS K 6922-2, temperature 190°C, load 2.16kg), density 0.923g / cm 3 The mixture was mixed with 75 parts by mass of pellets of 1,000 spunbonded cellulose (melting point 111°C) and polylactic acid (Luminiy PLA L-175, manufactured by Total Corbion PLA, MFR 4.5 g / 10 min (temperature 190°C, load 2.16 kg, density 1.25 g / cm3) as a biomass resin. 325 parts by mass of pellets with a melting point of 170°C and a biomass content of 100% were dry-blended and then kneaded in a twin-screw melt mixer to obtain mixed pellets. The kneading temperature was 220°C. The obtained mixed pellets were fed into an apparatus equipped with a single-screw extruder and a T-die, and melt-extruded at 300°C into a film having a thickness of 20 μm. The resulting film was then extruded into a paper base material (unbleached kraft paper manufactured by Oji Materia, basis weight 70 g / m 2 ) and pressure was applied with a nip roll to a cooling roll (temperature 20° C.) to obtain a resin laminate.

[0049] Example 2 A resin laminate was obtained in the same manner as in Example 1, except that the blending amount of the Novatec LD LC520 pellets was changed to 90 parts by mass, and the blending amount of the Luminiy PLA L-175 pellets was changed to 10 parts by mass.

[0050] Example 3 A resin laminate was obtained in the same manner as in Example 1, except that the blending amount of the Novatec LD LC520 pellets was changed to 80 parts by mass, and the blending amount of the Luminiy PLA L-175 pellets was changed to 20 parts by mass.

[0051] Example 4 A resin laminate was obtained in the same manner as in Example 1, except that the blending amount of the Novatec LD LC520 pellets was changed to 65 parts by mass, and the blending amount of the Luminiy PLA L-175 pellets was changed to 35 parts by mass.

[0052] Example 5 A resin laminate was obtained in the same manner as in Example 1, except that the blending amount of the Novatec LD LC520 pellets was changed to 55 parts by mass, and the blending amount of the Luminiy PLA L-175 pellets was changed to 45 parts by mass.

[0053] Example 6 Instead of Luminiy PLA L-175, we used BioPBS F791, a polybutylene succinate resin (manufactured by Mitsubishi Chemical, MFR 5g / 10min (temperature 190°C, load 2.16kg, density 1.26g / cm 3A resin laminate was obtained in the same manner as in Example 1, except that a polyester resin having a melting point of 115° C. and a biomass content of 50%) was used.

[0054] Example 7 Instead of Luminiy PLA L-175, we used semi-crystalline PHA, a polyhydroxyalkane (manufactured by CJ BIO, MFR 10g / 10min (temperature 190℃, load 2.16kg), density 1.23g / cm 3 A resin laminate was obtained in the same manner as in Example 1, except that a polystyrene resin having a melting point of 119° C. and a biomass content of 100%) was used.

[0055] Example 8 Instead of Novatec LD LC520, we used SBC818 (Braskem, MFR 8g / 10min (temperature 190°C, load 2.16kg, density 0.916g / cm3), a plant-derived polyethylene (bio-PE). 3 A resin laminate was obtained in the same manner as in Example 1, except that a polystyrene resin having a melting point of 108° C. and a biomass content of 95%) was used.

[0056] Comparative Example 1 Pellets of Novatec LD LC520 were fed into a device equipped with a single-screw extruder and a T-die, and melt-extruded into a film with a thickness of 20 μm. At the same time, the paper substrate (unbleached kraft paper made by Oji Materia, basis weight 70 g / m) was extruded. 2 ) and pressure was applied with a nip roll to a cooling roll (temperature 20° C.) to obtain a resin laminate.

[0057] Comparative Example 2 Pellets of Luminiy PLA L-175 were fed into an apparatus equipped with a single-screw extruder and a T-die, and melt-extruded into a film with a thickness of 20 μm. At the same time, a paper substrate (unbleached kraft paper made by Oji Materia, basis weight 70 g / m) was added. 2 ) and pressure was applied with a nip roll to a cooling roll (temperature 20° C.) to obtain a resin laminate.

[0058] Comparative Example 3 A resin laminate was obtained in the same manner as in Example 1, except that the blending amount of the Novatec LD LC520 pellets was changed to 95 parts by mass, and the blending amount of the Luminiy PLA L-175 pellets was changed to 5 parts by mass.

[0059] Comparative Example 4 A resin laminate was obtained in the same manner as in Example 1, except that the blending amount of the Novatec LD LC520 pellets was changed to 40 parts by mass, and the blending amount of the Luminiy PLA L-175 pellets was changed to 60 parts by mass.

[0060] Comparative Example 5 A resin laminate was obtained in the same manner as in Example 1, except that the blending amount of the Novatec LD LC520 pellets was changed to 25 parts by mass, and the blending amount of the Luminiy PLA L-175 pellets was changed to 75 parts by mass.

[0061] (evaluation) <Moisture permeability> The resin laminates obtained in the examples and comparative examples were set in a moisture permeability measuring device (L80-4000, manufactured by LYSSY), and the moisture permeability was measured under conditions of 40° C. and a relative humidity of 90%.

[0062] <Heat seal strength> The resin layers of the resin laminates obtained in the Examples and Comparative Examples were placed on top of each other and placed in a heat seal tester (TP701B, manufactured by Tester Sangyo Co., Ltd.) and laminated at a sealing temperature of 140°C or 170°C. The lamination conditions were 0.55 MPa for 1 second. Thereafter, the laminated product obtained was cut to a width of 15 mm, and the T-peel strength was measured using a Tensilon, and this T-peel strength was taken as the heat seal strength. In Table 1, if the seal strength was less than 7.0 N / 15 mm, it was evaluated as having easy peel properties (peeling at the interface of the resin layer), and if the seal strength was 7.0 N / 15 mm or more, it was evaluated as having complete seal properties (paper substrate material breakage).

[0063] <Biomass ratio> The biomass degree is the biomass degree relative to the total resin, and was calculated from the biomass degree of each biomass resin.

[0064] [Table 1]

[0065] In the resin laminate obtained in the examples, when the heat sealing temperature was 140°C, the seal strength was less than 7.0 N / 15 mm, so that easy peeling property was exhibited, and when the heat sealing temperature was 170°C, the seal strength was 7.0 N / 15 mm or more, so that complete peeling property was exhibited. Thus, the resin laminate obtained in the examples had two-stage heat sealing property (a property that allows easy peeling property and complete peeling property to be used separately depending on the heat sealing conditions). In addition, the resin laminate obtained in the examples had a high biomass degree and excellent moisture resistance. [Explanation of symbols]

[0066] 10 Paper base material 20 Mixed resin layer 30 Single resin layer 100 Resin laminate

Claims

1. A paper base material and a mixed resin layer provided on at least one surface side of the paper base material, The mixed resin layer contains a polyolefin resin and a biomass resin, The polyolefin resin is a plant-derived polyethylene, The biomass resin is at least one selected from the group consisting of polylactic acid, polybutylene succinate, polyhydroxyalkanoic acid, and polyamide 11; The content of the biomass resin is 10 to 49% by mass based on the total mass of the mixed resin layer, When the mixed resin layers are overlapped and heat-sealed at a heat sealing temperature of 140°C, the seal strength is less than 7.0 N / 15 mm, and when the mixed resin layers are overlapped and heat-sealed at a heat sealing temperature of 170°C, the seal strength is 7.0 N / 15 mm or more.

2. The resin laminate according to claim 1 , wherein in the mixed resin layer, the polyolefin resin and the biomass resin are mixed approximately uniformly.

3. A packaging material comprising the resin laminate according to claim 1 or 2.

4. A method for producing the resin laminate according to claim 1 or 2, A step of melt-mixing a polyolefin resin and a biomass resin to obtain a resin blend; and spreading the resin blend on a paper substrate by a coating method or a melt extrusion method.

5. The method for producing a resin laminate according to claim 4, wherein the melting temperature in the step of obtaining the resin blend is 180 to 330°C.

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