Mount for skin pack and skin pack packaging body

Abstract

To provide a mount for skin pack which is reduced in the occurrence of curl even under severe conditions such as a high-temperature and high-humidity environment, and which exhibits high strength as a mount.SOLUTION: A mount for skin pack has a thermoplastic resin layer on at least one surface of a paper base material, wherein a basis weight of the mount for skin pack is 300 g / m2 or more, and a king index of a pulp constituting the paper base material is 3,000 [1 / m] or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a skin pack liner and a skin pack packaging body. [Background technology]

[0002] In the field of food packaging, skin packs are used to maintain the freshness and extend the shelf life of food, in which the food is placed on a tray and the tray and food are vacuum-packed using a barrier film. Skin packs, especially when used to package meat and other foods, can suppress dripping (water that escapes from food during storage), which can extend the expiration date and reduce food waste, and so they are increasingly being used.

[0003] In light of this, taking into consideration design aspects such as printability and reduced environmental impact, skin packs have been developed in which food is placed on a paper backing and then sealed in film, instead of plastic trays made of polystyrene or polypropylene.

[0004] For example, Patent Document 1 discloses a skin pack backing paper having a specific air permeability, which has an uncoated paper with a specific basis weight, a design printed layer, and an adhesive layer formed from an aqueous emulsion heat-sensitive adhesive, for the purpose of producing a skin pack package by effectively absorbing a skin pack film.

[0005] Furthermore, Patent Document 2 discloses a skin pack package in which a backing sheet has a base material, a peel-off layer, and an adhesive layer, and a skin pack film is adhered to the base material via the adhesive layer, with the aim of providing a skin pack package that allows the packaged item to be easily removed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-172659 A [Patent Document 2] JP 2014-181075 A Summary of the Invention [Problem to be solved by the invention]

[0007] A skin pack mount using a paper substrate usually has a laminated structure with a resin layer on the paper substrate from the viewpoint of preventing deterioration when in contact with food and adhesion to the skin pack film. However, due to the difference in properties between paper and resin, curling may occur, especially under harsh conditions such as high temperature and humidity environments and environments with rapid temperature changes. If the skin pack mount curls, there is a problem that it becomes difficult to wrap with a skin pack film, and even if wrapping is possible, there are problems such as poor adhesion between the mount and the skin pack film and reduced design. Furthermore, since the skin pack mount is used to package contents such as meat, it must be strong enough to withstand the weight of the contents.

[0008] The present disclosure provides a mount for skin packs that reduces curling even under harsh conditions such as high temperature and humidity environments and has excellent strength as a mount. [Means for solving the problem]

[0009] As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by setting the basis weight of the mount and the kink index of the paper base material to specific ranges.

[0010] [1] A skin pack mount having a thermoplastic resin layer on at least one surface of a paper base material, The skin pack mount has a basis weight of 300 g / m 2 That's all. The kink index of the pulp constituting the paper base material is 3000 [1 / m] or less; Mounting paper for skin packs. [2] The paper substrate contains a sizing agent, The content of the sizing agent in the paper base material is 0.03 to 0.60 parts by mass per 100 parts by mass of the pulp constituting the paper base material. A skin pack mount according to [1]. [3] The content of the sizing agent in the paper base material is 0.25 to 0.40 parts by mass per 100 parts by mass of the pulp constituting the paper base material. The skin pack mount described in [2]. [4] The skin pack mount according to any one of [1] to [3], wherein the skin pack mount has a lateral breaking elongation of 5.5 to 7.5%, as measured in accordance with JIS P 8113:2006. [5] The mount for skin packs according to any one of [1] to [4], wherein the paper base material has a disintegration freeness of 350 to 600 mL. [6] The skin pack mount according to any one of [1] to [5], wherein the kink index of the pulp constituting the paper base material is 1800 to 2700 [1 / m]. [7] The skin pack mount described in any one of [1] to [6], wherein the paper base material is a laminate having, in order from the surface in contact with the thermoplastic resin layer, a paper base material layer A, an adhesive layer, and a paper base material layer B. [8] The skin pack liner according to [7], wherein the ratio of the kink index of the pulp constituting the paper base layer A to the kink index of the pulp constituting the paper base layer B (kink index of paper base layer A / kink index of paper base layer B) is 1.00 to 1.20. [9] [1] to [8], comprising a skin pack mount, a storage item, and a resin film, A skin pack packaging body, in which the item to be contained is contained between the skin pack backing and the resin film. Effect of the Invention

[0011] According to the present disclosure, it is possible to provide a backing sheet for a skin pack that reduces curling even under harsh conditions such as high temperature and humidity environments and has excellent strength as a backing sheet. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic diagram illustrating a method for evaluating the strength of a skin pack mount. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In this specification, the expressions "X to Y" and "X to Y" representing a numerical range mean a numerical range including the lower and upper limits, unless otherwise specified. When the lower and upper limits of a numerical range are individually stated, the numerical range includes any lower limit and any upper limit. It can be a combination of the above. Furthermore, for example, a description such as "at least one selected from the group consisting of X, Y, and Z" means any of X, Y, Z, a combination of X and Y, a combination of X and Z, a combination of Y and Z, or a combination of X, Y, and Z.

[0014] The "machine direction" refers to the machine direction (MD) of the paper substrate, which is the direction in which the fibers are oriented, and the "cross direction" refers to the direction perpendicular to the machine direction (CD).

[0015] <Skin pack mount> The skin pack mount of the present disclosure has a thermoplastic resin layer on at least one side of a paper base material. The inventors have found that, by satisfying both of the following requirements (A) and (B) in the skin pack mount, curling is reduced even under harsh conditions such as high temperature and humidity environments, and the mount has excellent strength. Requirement (A): The basis weight of the skin pack backing paper is 300 g / m 2 That's all. Requirement (B): The kink index of the pulp that constitutes the paper base material is 3000 [1 / m] or less.

[0016] Each requirement is explained below. First, regarding requirement (A), the basis weight of the skin pack mount is 300 g / m 2 That's all. The skin pack mount has a basis weight of 300 g / m 2 With a basis weight of 300g / m or more, the strength required for the backing paper is satisfactory. 2 If it is less than this, the strength will be insufficient to withstand the weight of the contents and it will be prone to sagging.

[0017] There is no upper limit on the basis weight of the skin pack mount, but from the viewpoint of processability, it is set to 800 g / m 2 The basis weight of the skin pack mount is preferably 350 to 800 g / m 2 , more preferably 450 to 700 g / m 2 , and more preferably 500 to 650 g / m 2 It is. Basis weight is measured in accordance with JIS P 8124:2011 ("Paper and paperboard -- Determination of basis weight", revised on March 22, 2011). The specific procedure is described below.

[0018] Next, requirement (B) is that the kink index of the pulp that constitutes the paper base material is 3000 [1 / m] or less. The kink index is an index of the amount of bent fibers in the pulp fibers, and the higher the kink index, the more bent fibers there are in the pulp fibers of the paper base material layer.

[0019] If the kink index is 3000 [1 / m] or less, it indicates that there are few bent fibers, and the moisture expansion rate is small, so that curling is more easily suppressed. Since the smaller the kink index, the better, there is no particular lower limit, but it is preferably 1700 [1 / m] or more.

[0020] The kink index can be controlled by the temperature when beating the pulp. The higher the beating temperature, the smaller the kink index, and the easier it is to control it within the above range. It can also be controlled by the pulp concentration when beating the pulp. Specifically, the higher the pulp concentration when beating, the higher the kink index tends to be. The method for measuring the kink index will be described later.

[0021] The kink index of the pulp constituting the paper base material is preferably 1700 to 3000 [1 / m], more preferably 1800 to 2700 [1 / m], and even more preferably 1800 to 2200 [1 / m]. When it is within this range, curling can be more easily suppressed.

[0022] As described above, by satisfying both of the above-mentioned requirements (A) and (B), the occurrence of curling is reduced even under harsh conditions such as high temperature and humidity environments, and the strength as a mount is excellent. Preferred embodiments of the mount for skin packs will be described below.

[0023] The lateral breaking elongation of the skin pack mount measured in accordance with JIS P 8113:2006 is preferably 5.5 to 7.5%, more preferably 5.5 to 6.5%, and even more preferably 5.5 to 6.3%. The breaking elongation indicates the ease with which the paper stretches. When the breaking elongation is equal to or less than the upper limit, curling can be more easily suppressed. Furthermore, when the breaking elongation is equal to or more than the lower limit, the strength of the mount is improved. The breaking elongation can be controlled by the freeness during beating. If the freeness is small, the breaking elongation tends to be large.

[0024] The thickness of the skin pack mount is preferably 350 to 900 μm, more preferably 500 to 800 μm, and further preferably 600 to 700 μm. The density of the skin pack mount is preferably 0.60 to 1.10 g / cm 3 and more preferably 0.70 to 1.00 g / cm 3 and more preferably 0.80 to 1.00 g / cm 3 It is. When the thickness and density are within the above ranges, the basis weight of the skin pack mount described above is easily satisfied.

[0025] (Paper base material) The skin pack mount is not particularly limited in terms of the constituent material and layer structure of the paper base material, as long as it satisfies the above basis weight and kink index. The paper base material may be a laminated paper including two or more paper base layers, or may be a single paper consisting of one paper base layer. From the viewpoints of barrier properties, mount strength, and ease of manufacture, it is preferable that the paper base material be a laminated paper.

[0026] When the paper substrate is a slip sheet, the number of paper substrate layers included in the slip sheet, the lamination method of each paper substrate layer, the physical properties of each paper substrate layer, etc. are not particularly limited. The paper substrate preferably has a paper substrate layer A, an adhesive layer, and a paper substrate layer B in this order. The slip sheet having the paper substrate layer A, the adhesive layer, and the paper substrate layer B in this order may be a slip sheet consisting of only the paper substrate layer A, the adhesive layer, and the paper substrate layer B, or may be a slip sheet in which another paper layer is laminated via an adhesive layer. In this case, the same paper layer as the paper substrate layer A may be used as the paper substrate layer B. Also, the same paper layer as the paper substrate layer A or the paper substrate layer B may be used as the other paper layer.

[0027] The paper substrate is preferably a laminate having, in order from the surface in contact with the thermoplastic resin layer, a paper substrate layer A, an adhesive layer, and a paper substrate layer B. The paper substrate may further have other paper substrate layers as long as the effects of the present disclosure are not impaired. As long as the relationship between the fiber orientation ratio and the basis weight is satisfied, the constituent materials and layer configurations of the paper substrate layer A and the paper substrate layer B (hereinafter sometimes simply referred to as "paper substrate layers") are not particularly limited. In this case, the paper base layer that contacts the thermoplastic resin layer is referred to as paper base layer A, but the thermoplastic resin layers may be provided on both sides of the paper base. In that case, the paper base layer with the larger basis weight is referred to as paper base layer A. If the basis weights are the same, one of them is referred to as paper base layer A and the other is referred to as paper base layer B.

[0028] Furthermore, when the paper base layer A is in contact with a thermoplastic resin layer, it is preferable that the basis weight of the paper base layer A and the basis weight of the paper base layer B satisfy the relationship of basis weight of paper base layer A ≧ basis weight of paper base layer B. Since the paper base layer A is in contact with the thermoplastic resin layer, it is less likely to absorb and release moisture than the paper base layer B. Therefore, by making the basis weight of the paper base layer A equal to or greater than the basis weight of the paper base layer B, the paper base is less susceptible to the effects of moisture, and curling can be further suppressed.

[0029] More preferably, the relationship of grammage of paper base layer A>grammage of paper base layer B is satisfied. This makes it easier to suppress curling. From the viewpoint of suppressing curling, the ratio of the grammage of paper base layer A to the grammage of paper base layer B (grammage of paper base layer A / grammage of paper base layer B) is 1.5 to 9.0. is preferable, 3.0 to 8.0 is more preferable, and 5.0 to 7.0 is even more preferable.

[0030] The basis weight of the paper base layer is not particularly limited as long as it satisfies the basis weight of the above-mentioned skin pack mount. The basis weight of the paper base layer A is preferably 200 to 1000 g / m 2 , more preferably 250 to 700 g / m 2 , and more preferably 300 to 600 g / m 2 , particularly preferably 350 to 550 g / m 2 It is.

[0031] The basis weight of the paper base layer B is preferably 30 to 600 g / m 2 , more preferably 40 to 500 g / m 2 , and more preferably 50 to 300 g / m 2 , and particularly preferably 50 to 200 g / m 2 It is.

[0032] The kink index of the paper base layer is not particularly limited as long as it satisfies the basis weight of the paper base layer described above. The kink index of the pulp constituting the paper base layer A is preferably 1700 to 3000 [1 / m], more preferably 1800 to 2700 [1 / m], and even more preferably 1800 to 2200 [1 / m]. The kink index of the pulp constituting the paper base layer B is preferably 1700 to 3000 [1 / m], more preferably 1800 to 2700 [1 / m], and even more preferably 1800 to 2200 [1 / m].

[0033] The ratio of the kink index of the pulp constituting the paper base layer A to the kink index of the pulp constituting the paper base layer B (kink index of paper base layer A / kink index of paper base layer B) is preferably 1.00 to 1.20, more preferably 1.00 to 1.10, and even more preferably 1.00 to 1.05. Within this range, the difference in moisture expansion / contraction rate between the paper base layers A and B becomes smaller, making it easier to suppress curling.

[0034] The basis weight of the paper base material is preferably 250 to 1000 g / m 2 , more preferably 400 to 800 g / m 2 , and more preferably 450 to 700 g / m 2 It is.

[0035] The paper base layer may be a single-layer structure by single-layer papermaking, or a multi-layer structure by multi-layer papermaking. From the viewpoint of being able to arbitrarily adjust the raw material composition, basis weight, papermaking conditions, etc. of each layer, the paper base layer is preferably a multi-layer structure. When the paper base layer has a multi-layer structure, the number of layers constituting the paper base layer is usually 2 to 10, preferably 3 to 9, more preferably 4 to 8, and even more preferably 4 to 6.

[0036] The paper base material preferably contains a sizing agent. The content of the sizing agent in the paper base material is preferably 0.03 to 0.60 parts by mass, more preferably 0.12 to 0.52 parts by mass, and even more preferably 0.25 to 0.40 parts by mass, relative to 100 parts by mass of the pulp constituting the paper base material. When the content of the sizing agent is equal to or greater than the lower limit, curling can be more easily suppressed. Furthermore, in many cases, printing is applied to skin pack mounts from the viewpoint of design. Although there is a trade-off between suppressing curling by using a sizing agent and achieving printability, when the content of the sizing agent is equal to or less than the upper limit, curling can be easily suppressed and printability can be achieved at the same time. The method for measuring the content ratio of the sizing agent will be described later.

[0037] The sizing agent is not particularly limited and may be any known sizing agent. Examples of the sizing agent include rosin-based sizing agents, alkyl ketene dimers, alkenyl succinic anhydrides, and styrene-containing polymers such as styrene-(meth)acrylate copolymers. The sizing agent is preferably a rosin-based sizing agent. Examples of the rosin-based sizing agent include acidic papermaking sizing agents, weakly acidic papermaking sizing agents, neutral papermaking sizing agents, and reinforced rosin-based sizing agents.

[0038] The disintegrated freeness of the paper base material is preferably 350 to 600 mL, more preferably 400 to 600 mL, and even more preferably 500 to 600 mL. Disintegrated freeness refers to the Canadian standard freeness measured in accordance with JIS P 8121-2:2012 ("Pulp-Disintegration Method-Part 1: Disintegration of Chemical Pulp", established on April 20, 2012) for pulp obtained by disintegrating paper after papermaking in accordance with JIS P 8220-1:2012 ("Pulp-Freeness Test Method-Part 2: Canadian Standard Freeness Method", established on June 20, 2012). By setting the disintegrated freeness in the above range, it becomes easier to set the elongation of the paper base material in a more appropriate range, and it becomes easier to control the breaking elongation in the above range. Therefore, curling becomes easier to be suppressed. The disintegration freeness can be controlled by the freeness in beating the pulp during papermaking, and is usually about 50 mL greater than the freeness of the pulp.

[0039] The paper base layer is not particularly limited as long as it is a commonly used paper, and is preferably paper whose main component is plant-derived pulp, and more preferably paper whose main component is wood pulp. Specific examples of the paper base layer include kraft paper, fine paper, (white) paperboard, base paper for paper containers, milk carton base paper, cup base paper, liner paper, coated paper, one-sided gloss paper, glassine paper, and graphene paper. Among these, the paper base layer is preferably a paper selected from the group consisting of kraft paper, fine paper, (white) paperboard, base paper for paper containers, cup base paper, and one-sided gloss paper, and from the viewpoint of rigidity, it is more preferable that the (white) paperboard is a paper selected from the group consisting of high-grade paperboard, special paperboard, cup base paper, and kraft paper. Examples of kraft paper include bleached kraft paper, unbleached kraft paper, and one-sided gloss bleached kraft paper. Among these, the kraft paper is preferably a paper selected from the group consisting of bleached kraft paper and one-sided gloss bleached kraft paper from the viewpoint of printability and hygiene.

[0040] As described above, the pulp constituting the paper base layer is preferably wood pulp, and more preferably kraft pulp. Kraft pulp includes hardwood kraft pulp (LKP) and softwood kraft pulp (NKP) based on the difference in raw materials. As hardwood kraft pulp (LKP), hardwood bleached kraft pulp (LBKP) is preferable, and as softwood kraft pulp (NKP), softwood bleached kraft pulp (NBKP) is preferable. In addition, as the difference in processing state, bleached kraft pulp (BKP), unbleached kraft pulp (UKP), and oxygen bleached kraft pulp (OKP) are mentioned, and from the viewpoint of printability, bleached kraft pulp (BKP) is preferable.

[0041] Among these, the pulp is preferably one or more selected from the group consisting of hardwood kraft pulp (LKP) and softwood kraft pulp (NKP), and more preferably a mixture of hardwood kraft pulp (LKP) and softwood kraft pulp (NKP). In the mixture, the mass ratio of hardwood kraft pulp (LKP) to softwood kraft pulp (NKP) (LKP / NKP) is not particularly limited as long as it is a ratio used in general paper, and is preferably 1 / 99 to 99 / 1, more preferably 30 / 70 to 70 / 30, and even more preferably 40 / 60 to 60 / 40.

[0042] The Oken smoothness (JIS P 8155:2010) of the paper base layer is preferably 5 seconds or more, more preferably 10 seconds or more and 1,000 seconds or less. From the viewpoint of printability, the 75° gloss of the paper base layer is preferably 5% or more, more preferably 10% or more and 70% or less.

[0043] (adhesive layer) When the paper base material is a slip sheet, the adhesive layer that bonds the paper base material layer A and the paper base material layer B is preferably a layer made of a material having adhesive properties, and preferably contains a thermoplastic resin. By using a thermoplastic resin, the slip sheet can be easily obtained by coating at least one of the paper base material layers with a heat-melted adhesive layer and laminating the other paper base material layer.

[0044] The thermoplastic resin preferably contains one or more resins selected from the group consisting of polyolefin-based resins, polyester-based resins, polylactic acid, styrene-based resins, and acrylic-based resins, and more preferably contains a polyolefin-based resin. Examples of polyolefin resins include polyethylene (low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), etc.), polypropylene (PP), and polymethylpentene. Examples of polyester resins include polyethylene terephthalate and polybutylene terephthalate. Examples of the styrene resin include polystyrene, acrylonitrile styrene, and acrylonitrile butadiene styrene. Examples of acrylic resins include polymers and copolymers of acrylic monomers such as acrylic acid esters. Among these, the polyolefin resin is preferably one or more selected from the group consisting of polyethylene and polypropylene, more preferably one or more selected from the group consisting of LDPE and MDPE, and even more preferably MDPE.

[0045] The following adhesives may be used as the adhesive layer. The adhesive is not particularly limited, and may be a water-based adhesive, a solvent-based adhesive, a UV-based adhesive, or the like. Among these, the adhesive used in the adhesive layer is preferably a water-based adhesive. The water-based adhesive is preferably one or more selected from the group consisting of an acrylic adhesive, a polyurethane adhesive, and an isocyanate adhesive, and is more preferably an acrylic adhesive in terms of ease of control of adhesive strength and excellent heat resistance.

[0046] The amount of the adhesive layer per unit area is not particularly limited, but is preferably 1.0 g / m 2 More than 50.0g / m 2 Less than 1.0 g / m, more preferably 1.0 g / m 2 More than 20.0g / m 2 When forming the adhesive layer, it is preferable to coat the adhesive on the paper base layer A and / or the paper base layer B so that the solid content is in this amount.

[0047] The adhesive layer may be formed as a single layer of a single resin, or may be formed as a single layer of a mixture of multiple resins, or may be formed as multiple layers made of the same or different types of resins. The thickness of the adhesive layer is not particularly limited, but is preferably 5 to 100 μm, and more preferably 10 to 50 μm.

[0048] (thermoplastic resin layer) The skin pack mount has a thermoplastic resin layer on at least one surface of a paper substrate. When the paper substrate is a slip sheet, the paper substrate layer in contact with the thermoplastic resin layer is the paper substrate layer A. The thermoplastic resin layer protects the surface of the skin pack mount from stored items such as food, and protects the stored items from external stimuli such as oxygen. In addition, for example, when the stored items are sandwiched between the skin pack mount and a resin film, the thermoplastic resin layer adheres to the resin film.

[0049] The thermoplastic resin layer may be a single layer of a thermoplastic resin or a laminate containing a thermoplastic resin. However, it is preferable that the layer is a laminate containing a barrier layer, and in particular, a laminate having a barrier layer between thermoplastic resin layers, such as "thermoplastic resin layer / barrier layer / thermoplastic resin layer." It is preferable that the thermoplastic resin layer is a laminate layer.

[0050] When the thermoplastic resin layer is a laminate having a barrier layer, the barrier layer is not particularly limited as long as it is a layer that can barrier oxygen and / or water vapor, and may have a single layer structure or a multilayer structure of two or more layers.

[0051] Specifically, the resin forming the barrier layer is preferably one or more selected from the group consisting of polyamide resins, polyvinyl alcohol, ethylene-vinyl alcohol copolymers (EVOH), and polyvinylidene chloride resins, and more preferably one or more selected from the group consisting of polyamide resins, polyvinyl alcohol, and ethylene-vinyl alcohol copolymers. The polyamide resin is preferably an aromatic polyamide, and more preferably polyamide MXD6. The barrier layer may further contain one or more other resins such as biomass resins and biodegradable resins. Alternatively, the barrier layer may be a metal layer.

[0052] The thickness of the barrier layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 3 to 50 μm, and further preferably 5 to 30 μm.

[0053] The thermoplastic resin used in the thermoplastic resin layer is preferably one that can be laminated to the paper base layer. The thermoplastic resin may be appropriately selected from known thermoplastic resins. Specific examples include polyester-based resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactic acid, and polybutylene succinate; polyolefin-based resins such as polyvinyl chloride, polyvinylidene chloride, polybutene, polybutadiene, ethylene-vinyl acetate copolymer, polyethylene, polypropylene, ethylene-vinyl alcohol copolymer, ethylene-propylene copolymer, and polymethylpentene; polycarbonate; polyurethane; polyamides such as nylon 6; polyacrylonitrile; and poly(meth)acrylate.

[0054] Among these thermoplastic resins, the thermoplastic resin used in the laminate layer is preferably one or more selected from the group consisting of polyethylene (PE) and polypropylene (PP) because of its excellent extrusion lamination properties and barrier properties. In addition, the PE is preferably one or more selected from the group consisting of low density polyethylene (LDPE) and medium density polyethylene (MDPE) because of its excellent extrusion lamination properties.

[0055] The total thickness of the thermoplastic resin layer is not particularly limited, but is preferably 1 to 200 μm, more preferably 1 to 100 μm, even more preferably 5 to 50 μm, and even more preferably 10 to 40 μm.

[0056] Commercially available resin laminates (laminated films) suitable for use in the thermoplastic resin layer include a non-oriented multilayer film made of nylon-ethylene vinyl alcohol copolymer manufactured by Mitsubishi Chemical Corporation (product name: Diamiron MF F903, thickness 40 μm), a three-layer film of PP (polypropylene) / PVOH (polyvinyl alcohol) / PP manufactured by Futamura Chemical Industry Co., Ltd. (product name: ECO-B, thickness 20 μm), a three-layer film of NY6 (nylon 6) / EVOH (ethylene-vinyl alcohol copolymer) / NY6 manufactured by Gunze Limited (product name: Heptax HP, thickness 17 μm), and a three-layer film of NY6 / MXD6 (polyamide MXD6) / NY6 manufactured by Unitika Limited (product name: Embron M, thickness 15 μm).

[0057] (Adhesive layer) When the surface of the thermoplastic resin layer has adhesive properties, the thermoplastic resin layer is directly bonded to the surface of the paper base material. However, in order to prevent peeling during production, transportation and display of the skin pack package, it is preferable to have an adhesive layer between the paper substrate and the thermoplastic resin layer. The adhesive constituting the adhesive layer is not particularly limited, but is preferably a resin-based adhesive suitable for dry lamination and wet lamination. Specifically, the adhesive constituting the adhesive layer may be of a water-based, solvent-based, UV-based, or other type, and among these, a water-based adhesive is preferred. Among the water-based adhesives, at least one selected from the group consisting of an acrylic adhesive, a polyurethane adhesive, and an isocyanate adhesive is preferred, and an acrylic adhesive is more preferred.

[0058] The amount of adhesive layer per unit area is 1 to 50 g / m 2 and more preferably 1 to 20 g / m 2 It is preferable to coat the pressure-sensitive adhesive layer on the surface of the paper substrate or the surface of the thermoplastic resin layer so that the solid content is within this range. For coating, it is preferable to use a coating liquid containing the pressure-sensitive adhesive, and it is more preferable to use a mixed coating liquid in which a curing agent is mixed into a coating liquid containing the pressure-sensitive adhesive.

[0059] The thickness of the pressure-sensitive adhesive layer is not particularly limited, but from the viewpoint of moldability, it is preferably from 5 μm to 100 μm, more preferably from 8 μm to 30 μm.

[0060] (other layers) The skin pack mount according to the present embodiment may include other layers as long as the effects of the present disclosure are not impaired. For example, the skin pack mount may be a paper base material having a printed layer made of ink formed by offset printing on one or both sides of the paper base material. When the skin pack mount has a printed layer, it is preferable to provide a thermoplastic resin layer on the surface of the printed layer via an adhesive layer.

[0061] <Manufacturing method for skin pack mount> The method for producing the skin pack mount according to the present embodiment is not particularly limited, and any known method can be used. An example of the production method is shown below.

[0062] (Preparation of paper base layer) First, a paper base layer is obtained by making a paper material containing pulp. The obtained paper base layer can be used as a single paper to form a paper base material. If necessary, the obtained paper base layer can be bonded together with an adhesive layer to obtain a paper base material.

[0063] The freeness (freeness) of the pulp during papermaking is preferably 300 to 700 mL, more preferably 350 to 600 mL, and further preferably 450 to 550 mL. The freeness here refers to the Canadian standard freeness measured in accordance with JIS P8121:2012. The method of beating the pulp to adjust the freeness can be a known method.

[0064] From the viewpoint of controlling the kink index, the temperature during beating is preferably from 30 to 70°C, more preferably from 40 to 60°C, and even more preferably from 50 to 60°C. In addition, when preparing the pulp, internal additives may be added to the pulp, such as sizing agents, fillers, paper strength agents, retention aids, pH adjusters, drainage improvers, water resistance agents, softeners, antistatic agents, defoamers, slime control agents, dyes, and pigments.

[0065] For example, it is possible to use a rosin-based sizing agent, a paper strength agent, aluminum sulfate, etc. The amount of the paper strength agent is preferably 0.05 to 0.50 parts by mass with respect to 100 parts by mass of pulp.

[0066] The obtained pulp is added with an internal additive as necessary to obtain a paper stock, which is then made into paper. In the paper making process, a known wet paper machine can be appropriately selected and used. Examples of the paper machine include a twin wire paper machine, a fourdrinier paper machine, a gap former type paper machine, a cylinder paper machine, and a short wire paper machine.

[0067] The obtained paper base layer may be subjected to a surface treatment using a calendar to make the thickness and profile uniform. For the calendar treatment, a known calendaring machine can be appropriately selected and used.

[0068] When the paper base material is a single sheet, the obtained paper base material layer can be used as the paper base material and a thermoplastic resin layer can be provided to obtain a skin pack mount. When the paper base material is a slip sheet, there is no particular restriction on the procedure for forming the skin pack liner after obtaining the paper base material layer A and the paper base material layer B. The paper base material layer A and the paper base material layer B may be bonded together via an adhesive layer to obtain a paper base material, and then a thermoplastic resin layer may be provided to obtain the skin pack liner. The skin pack liner may be obtained by providing a thermoplastic resin layer on the paper base material layer A, and providing an adhesive layer and the paper base material layer B on the side of the paper base material layer A opposite to the side in contact with the thermoplastic resin layer, thereby obtaining the skin pack liner.

[0069] It is preferable to first carry out the lamination step of the paper base layer A and the paper base layer B. For example, the surface of one of the paper base layers can be coated with the resin contained in the heat-melted adhesive layer, and the other paper base layer can be laminated to the coated surface to obtain a paper base that is a laminate.

[0070] Alternatively, a paper substrate layer as a laminate can be obtained by applying an adhesive coating liquid containing an aqueous solution or emulsion in which the resin contained in the adhesive layer is dissolved or dispersed in water to the surface of one of the paper substrate layers, removing some or all of the moisture as necessary, and laminating the other paper substrate layer on the applied surface. In this case, for example, a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a rod blade coater, a lip coater, a die coater, or a curtain coater can be used as a method for applying the adhesive coating liquid. For removing moisture, it is preferable to use drying with hot air or drying with infrared radiation. If necessary, a printing step of printing on the surface of the paper base layer or a printing layer lamination step of providing a printed layer may be performed either before or after the lamination step of each paper base layer.

[0071] (Formation of Thermoplastic Resin Layer) When a thermoplastic resin layer is provided on one or both sides of a paper substrate, the thermoplastic resin layer may be directly adhered to the paper substrate, or may be adhered to the paper substrate via an adhesive layer. In the latter case, it is preferable to apply a coating liquid containing an adhesive onto the surface of the paper substrate, and then laminate the thermoplastic resin layer onto the surface of the paper substrate via the adhesive layer. In this case, a film may be attached to the paper substrate as the thermoplastic resin layer.

[0072] (processing) The skin pack mount obtained as described above may be cut to an appropriate size, taking into consideration the size and shape of the contents to be stored, and suitability for transportation and display. From the viewpoint of efficiently obtaining skin pack mounts of the same shape, cutting is preferably performed by punching. The punching process is preferably carried out using a high-speed automatic punching machine, a flat-bed punching machine, or a rotary punching machine, and more preferably a high-speed automatic punching machine. By carrying out the punching process using a high-speed automatic punching machine or a flat-bed punching machine, skin pack mounts having shapes such as a rectangle, a rounded rectangle, an ellipse, and the like can be easily and efficiently obtained.

[0073] <Skin pack packaging> The present disclosure relates to a skin pack package having the above-mentioned skin pack mount, a storage item, and a resin film, the storage item being stored between the skin pack mount and the resin film. The skin pack package according to the present embodiment is preferably one that hermetically stores the storage item.

[0074] The resin film can be appropriately selected depending on the type and shape of the stored item, but preferably has excellent adhesiveness and is peelable when the stored item is removed, since it needs to be adhered to the thermoplastic resin layer of the skin pack mount to store the stored item. Therefore, the resin film is preferably made of the thermoplastic resin used in the above-mentioned thermoplastic resin layer, and more preferably has a barrier layer when the contents are food, etc. As the barrier layer, the barrier layer used in the above-mentioned thermoplastic resin layer is preferably used.

[0075] There are no restrictions on the items to be stored, and examples include food, daily necessities, etc., but preferably, since the items to be stored can be sealed, it is suitable for storing fresh foods such as vegetables, meat, fresh fish, and other processed foods. EXAMPLES

[0076] The present invention will be described in more detail below with reference to examples and comparative examples. The materials, amounts, ratios, processing contents, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present disclosure. Therefore, the scope of the present disclosure should not be interpreted as being limited by the specific examples shown below.

[0077] <Example 1> (Paper base layer A) 50 parts by mass of bleached hardwood kraft pulp (LBKP) and 50 parts by mass of bleached softwood kraft pulp (NBKP) were beaten at a temperature of 55°C to a Canadian standard freeness (CSF) of 500 mL to obtain a pulp slurry. A double disk refiner was used for the beating. 0.60 parts by mass (solids equivalent) of aluminum sulfate (liquid aluminum sulfate manufactured by Asahi Chemical Industry Co., Ltd.), 0.20 parts by mass (solids equivalent) of an internal paper strength enhancer (Polystron 1430 manufactured by Arakawa Chemical Industry Co., Ltd.), and 0.32 parts by mass (solids equivalent) of an internal rosin sizing agent (Sizepine N-817 manufactured by Arakawa Chemical Industry Co., Ltd.) were added to 100 parts by mass of pulp (solids) in the obtained pulp slurry to prepare five layers of paper materials for the surface layer, the surface underlayer, the middle layer, the back underlayer, and the back layer. Using this stock, paper was made using a five-ply twin-wire paper machine with the same basis weight for all five plies. The basis weight was 450 g / m 2 Thereafter, a smoothing treatment was carried out using a calendar to obtain a paper base layer A.

[0078] (Paper base layer B) 50 parts by mass of bleached hardwood kraft pulp (LBKP) and 50 parts by mass of bleached softwood kraft pulp (NBKP) were beaten at a temperature of 55°C to a Canadian standard freeness (CSF) of 500 mL to obtain a pulp slurry. A double disk refiner was used for the beating. 0.60 parts by mass (solids equivalent) of aluminum sulfate (liquid aluminum sulfate manufactured by Asahi Chemical Industry Co., Ltd.), 0.20 parts by mass (solids equivalent) of an internal paper strength enhancer (Polystron 1430 manufactured by Arakawa Chemical Industry Co., Ltd.), and 0.32 parts by mass (solids equivalent) of an internal rosin sizing agent (Sizepine N-817 manufactured by Arakawa Chemical Industry Co., Ltd.) were added to 100 parts by mass of pulp (solids) in the obtained pulp slurry to prepare five layers of paper materials for the surface layer, the surface underlayer, the middle layer, the back underlayer, and the back layer. This paper stock was used to make a five-ply paper using a twin-wire paper machine with the same basis weight for all five plies. The basis weight was 70 g / m 2 Thereafter, a smoothing treatment was carried out using a calendar to obtain a paper base layer B.

[0079] (Paper base lamination process) One side of paper base layer A was melt-extrusion coated with MDPE (8010 manufactured by ENEOS NUC) as an adhesive layer to a dry film thickness of 20 μm, and paper base layer B was laminated to the coated surface to obtain a two-layer paper base.

[0080] (Lamination process) A non-oriented multilayer film (Diamilon MF F903, Mitsubishi Chemical Corporation; film thickness 40 μm) made of nylon-ethylene vinyl alcohol copolymer as a thermoplastic resin layer was coated on one side with a coating weight of 6.0 g / m2 after heat drying. 2 A water-based acrylic adhesive (Polystick EM-575 manufactured by Arakawa Paint Industries Co., Ltd.) was applied using a reverse roll coater so that the thickness of the adhesive-coated surface was 100 μm or more. Next, the two-layered paper base layer A side obtained as described above was attached to the adhesive-coated surface, and dry laminated to obtain a skin pack mount.

[0081] <Example 2> A paper base layer A was obtained in the same manner as in Example 1, except that beating was performed under a temperature condition of 45° C. A paper base layer B was obtained in the same manner as in Example 1, except that beating was performed under a temperature condition of 45° C. The obtained paper base layer A and paper base layer B were used to obtain a skin pack liner in the same manner as in Example 1.

[0082] <Example 3> A paper base layer A was obtained in the same manner as in Example 1, except that beating was performed under a temperature condition of 35° C. A paper base layer B was obtained in the same manner as in Example 1, except that beating was performed under a temperature condition of 35° C. The obtained paper base layer A and paper base layer B were used to obtain a skin pack mount in the same manner as in Example 1.

[0083] <Example 4> Basis weight: 200g / m 2 A paper base layer A was obtained in the same manner as in Example 2, except that the basis weight was 90 g / m 2 Except for this, a paper base layer B was obtained in the same manner as in Example 2. A skin pack mount was obtained in the same manner as in Example 1 using the obtained paper base layer A and paper base layer B.

[0084] <Example 5> A paper base layer A was obtained in the same manner as in Example 2. The basis weight was 240 g / m 2 Except for this, a paper base layer B was obtained in the same manner as in Example 2. A skin pack mount was obtained in the same manner as in Example 1 using the obtained paper base layer A and paper base layer B.

[0085] <Example 6> Except for adding 0.54 parts by mass (solid content equivalent) of the internal rosin sizing agent, a paper base layer A was obtained in the same manner as in Example 2. Also, except for adding 0.54 parts by mass (solid content equivalent) of the internal rosin sizing agent, a paper base layer B was obtained in the same manner as in Example 2. Using the obtained paper base layer A and paper base layer B, a skin pack liner was obtained in the same manner as in Example 1.

[0086] <Example 7> A paper base layer A was obtained in the same manner as in Example 2, except that 0.16 parts by mass (solid content equivalent) of the internal rosin sizing agent was added. A paper base layer B was obtained in the same manner as in Example 2, except that 0.16 parts by mass (solid content equivalent) of the internal rosin sizing agent was added. A skin pack liner was obtained in the same manner as in Example 1 using the obtained paper base layer A and paper base layer B.

[0087] <Example 8> A paper base layer A was obtained in the same manner as in Example 2, except that 0.06 parts by mass (solid content equivalent) of the internal rosin sizing agent was added. A paper base layer B was obtained in the same manner as in Example 2, except that 0.06 parts by mass (solid content equivalent) of the internal rosin sizing agent was added. A skin pack liner was obtained in the same manner as in Example 1 using the obtained paper base layer A and paper base layer B.

[0088] <Example 9> A paper base layer A was obtained in the same manner as in Example 2, except that the paper was beaten to a Canadian standard freeness (CSF) of 400 mL. A paper base layer B was obtained in the same manner as in Example 2, except that the paper was beaten to a Canadian standard freeness (CSF) of 400 mL. A skin pack liner was obtained in the same manner as in Example 1 using the obtained paper base layer A and paper base layer B.

[0089] <Example 10> A paper base layer A was obtained in the same manner as in Example 2, except that the paper was beaten to a Canadian standard freeness (CSF) of 350 mL. A paper base layer B was obtained in the same manner as in Example 2, except that the paper was beaten to a Canadian standard freeness (CSF) of 350 mL. A skin pack liner was obtained in the same manner as in Example 1 using the obtained paper base layer A and paper base layer B.

[0090] <Example 11> Basis weight: 520g / m 2 A paper base layer A was obtained in the same manner as in Example 1, except that the paper base layer A was used as the paper base. Thereafter, a thermoplastic resin layer was provided in the same manner as in the lamination process of Example 1, to obtain a skin pack mount.

[0091] <Comparative Example 1> A paper base layer A was obtained in the same manner as in Example 1, except that beating was performed under a temperature condition of 25° C. A paper base layer B was obtained in the same manner as in Example 1, except that beating was performed under a temperature condition of 25° C. The obtained paper base layer A and paper base layer B were used to obtain a skin pack liner in the same manner as in Example 1.

[0092] <Comparative Example 2> Basis weight: 100g / m 2 Except for the above, a paper base layer A was obtained in the same manner as in Example 2. A paper base layer B was obtained in the same manner as in Example 2. A skin pack mount was obtained in the same manner as in Example 1 using the obtained paper base layer A and paper base layer B.

[0093] The physical properties of the skin pack mounts prepared in the Examples and Comparative Examples were measured and evaluated by the following methods. The results are shown in Table 1.

[0094] [Basic weight] The basis weights of the skin pack liner and the paper base layer were measured in accordance with JIS P 8124:2011 ("Paper and paperboard -- Determination of basis weight," revised March 22, 2011). When measuring the basis weight of the paper base layer (paper base layer A and paper base layer B in the case of interleaving paper) from the skin pack mount, the paper base layer can be separated by the following procedure. The skin pack mount is placed in a beaker containing xylene heated to 100°C, and left to stand for 30 minutes while immersed in the xylene to dissolve the thermoplastic resin. The thermoplastic resin remaining on the surface of the paper base layer is wiped off with a rag, and if any thermoplastic resin remains, it is immersed in xylene again, and the process is repeated until the thermoplastic resin is completely removed. If the paper base layer is interleaving paper, the xylene treatment also separates paper base layer A and paper base layer B. After the work, the paper base layers A and B are subjected to sufficient evaporation of xylene in a draft or the like, and then the moisture is conditioned in a humidity-conditioning environment specified in JIS P 8111:1998 before being used to measure the basis weight.

[0095] <Kink index> First, the thermoplastic resin layer is removed from the skin pack mount by the above-mentioned xylene treatment to obtain a paper base material. The divided paper base layer is cut into 40 cm squares, soaked in ion-exchanged water, adjusted to a concentration of 2%, and soaked for 24 hours. After soaking for 24 hours, it is processed using a standard disintegrator (manufactured by Kumagai Riki Kogyo Co., Ltd.) in accordance with JISP8220-2:2012 until there is no undisintegrated fiber. The pulp is broken down into fibers by processing. The slurry after disintegration (dispersion of pulp fibers) is adjusted to a solids concentration of 0.1% by mass, and the pulp solids concentration is calculated in accordance with JIS P8225:2003. The slurry after disintegration is adjusted to a solids concentration of 0.004% by mass, and 500 g of slurry is obtained, and the amount taken is recorded. The solids concentration and the amount of slurry taken are used to calculate the dry weight of the sample. The obtained slurry is used to measure the "kink index" using a fiber length measuring device (model: Valmet FS-5 with UHD base unit, manufactured by Valmet Co., Ltd.).

[0096] The kink index (1 / m) in this disclosure is the Kibblewhite's kink index calculated by the following formula (1). The kink index is calculated by weighting the number of kinks in each angle range according to the increase in angle and dividing the weighted number by the total fiber length. The measurement is performed in accordance with ISO 16065-2:2007. The device also has an attached camera that can detect and measure each individual fiber, taking pictures in a measurement cell with a depth of field of 0.5 mm according to the ISO 16505-2:2007 standard. The device captures fiber lengths between 0.01 mm and 10.00 mm.

number

[0097] The symbols in formula (1) represent the following: n1 = Number of kinks (bends) between 21° and 45° in the measurement sample n2 = Number of kinks (bending angles) between 46° and 90° in the measurement sample n3 = Number of kinks (bending angles) between 91° and 180° in the measurement sample L c = Total fiber length of the measured sample (m) When the paper base material is a single sheet, the kink index obtained is taken as the kink index of the pulp that constitutes the paper base material. When the paper base material is a laminated paper, the kink index of each paper base layer is measured after separation, and the weighted average according to the basis weight of the paper base layer is taken as the kink index. For example, when the paper base material has paper base layer A and paper base layer B, it is calculated using the following formula. Kink index when the paper base material is a slip sheet = Kink index of paper base layer A × (basis weight of paper base layer A / sum of basis weight of paper base layer A and basis weight of paper base layer B) + Kink index of paper base layer B × (basis weight of paper base layer B / sum of basis weight of paper base layer A and basis weight of paper base layer B)

[0098] <Thickness> In accordance with JISP8118:2014, measure the thickness of the skin pack mount after humidity conditioning in the humidity-controlled environment specified in JISP8111:1998. A paper thickness gauge (company name: Toyo Seiki Seisakusho Co., Ltd., model number: No. 132 digital thickness gauge) can be used as the measuring device. Ten points of the sample are measured, and the arithmetic average value is used.

[0099] <density> From the measured basis weight and thickness, the basis weight value (g / m 2 Calculate the density using the formula: ) ÷ paper thickness (μm).

[0100] <Breaking elongation> The horizontal breaking elongation of the skin pack mount is specified in JIS P 8111:1998. After conditioning the moisture in a humidity-controlled environment, the measurements are made in accordance with JIS P 8113:2006 (Testing methods for tensile properties of paper and paperboard). The tests are performed using a horizontal tensile tester (manufactured by L&W, CODE SE-064). Specifically, a skin pack mount that has been left to stand for at least one day in an environment of 23±1°C and 50±2% relative humidity as a temperature and humidity control treatment is cut into a sample with a width of 15 mm and a length of 150 mm. The sample is attached to a tensile tester with a chuck distance of 100 mm, and a tensile test is performed at a speed of 10 mm / min to measure the breaking elongation in the CD (transverse direction). The arithmetic mean value of the 10 samples is taken.

[0101] <Content of sizing agent> The thermoplastic resin layer is removed from the skin pack mount by the above-mentioned xylene treatment to obtain a paper base material. After taking 150 μg of the paper base material, the content of the sizing agent is measured by mass spectrometry using a pyrolysis GC / MS decomposition device (Agilent Technologies, Inc.). The values ​​represent the content (parts by mass) relative to 100 parts by mass of the pulp that constitutes the paper base material. When the paper base material is an interleaving paper, for example when the paper base material has paper base material layer A and paper base material layer B, the content of sizing agent in each paper base material layer is measured, and then the weighted average value according to the above-mentioned basis weight is used as the kink index.

[0102] <Disintegration Freeness> The thermoplastic resin layer is removed from the skin pack mount by the above-mentioned xylene treatment to obtain a paper base material. The obtained paper base material is disintegrated in accordance with JIS P 8220-1:2012 ("Pulp-Disintegration method-Part 1: Disintegration of chemical pulp", established on April 20, 2012) to obtain a pulp slurry. The obtained pulp slurry is measured in accordance with JIS P 8121-2:2012 ("Pulp-Freeness test method-Part 2: Canadian standard freeness method", established on June 20, 2012). The measuring device used was a Canadian Freeness Tester (measuring funnel type: modified type) manufactured by Kumagai Riki Kogyo Co., Ltd.

[0103] [Curl Evaluation] Each skin pack mount produced in the Examples and Comparative Examples was punched into a rectangle of 280 mm length x 180 mm width. An automatic flat-plate punching machine (Carton Master AP-1300-TSG-8, manufactured by Asahi Machinery Co., Ltd.) was used for punching. The obtained sample was left to stand for 24 hours in a high-temperature and high-humidity environment at a temperature of 40°C and a relative humidity of 90% (constant temperature and humidity tester PR-3KP, manufactured by Espec Corporation). After that, the curl state of the mount was checked after 5 minutes. The mount was placed flat on a horizontal hard surface, and the lifting of each of the four corners of the mount was measured, and the average value was used and evaluated according to the following criteria. When placing the mount flat on a horizontal hard surface, the paper base side was placed flat on the hard surface and the lifting was measured. If no lifting occurred, the thermoplastic resin layer side was placed flat on the hard surface and the lifting was measured, and the result was used.

[0104] Evaluation criteria A: The average of the four corners is less than 4 mm B: The average of the four corners is 4 mm or more and less than 7 mm C: The average of the four corners is 7 mm or more and less than 10 mm D: The average of the four corners is 10 mm or more

[0105] [Printability evaluation] The paper base materials obtained in the examples and comparative examples were cut into flat sheets measuring 550 mm in length and 800 mm in width, and 50 sheets of each were offset printed (on an offset printing machine L-644 manufactured by Komori Corporation, Color: Black, solid printing) After printing, the printed surface was observed and evaluated according to the following criteria. A: There is no sign of uneven ink density (uneven printing). B: Slight printing unevenness is observed, but it does not cause any practical problems. C: There are printing irregularities.

[0106] [Strength of mount] The skin pack mounts obtained in the Examples and Comparative Examples were punched into rectangles measuring 280 mm in length and 180 mm in width using an automatic flat-plate punching machine (Carton Master AP-1300-TSG-8, manufactured by Asahi Machinery Co., Ltd.). The obtained sample was fixed on four square stands. Specifically, as shown in Figures 1A and 1C, the evaluation paper piece 11 was placed on four square stands 13 so that the four corners of the evaluation paper piece 11 were placed on each stand at 1 cm x 1 cm. Then, as shown in Figures 1B and 1C, one weight 15 of 200 g (oval shape with major axis 150 mm x minor axis 100 mm) was placed on the center of the evaluation paper piece 11, and the degree of bending was confirmed. The number of centimeters that the evaluation paper piece 11 sunk was measured from both the vertical and horizontal directions, and the evaluation was made based on the larger bending according to the following criteria. A: Deflection is less than 2.50 cm B: Deflection is 2.50 cm or more

[0107] [Table 1] In the table, the sizing agent content is expressed in parts by mass relative to 100 parts by mass of the pulp constituting the paper base material.

Claims

1. A skin pack mount having a thermoplastic resin layer on at least one surface of a paper base material, The skin pack mount has a basis weight of 300 g / m ２ That's all. The kink index of the pulp constituting the paper base material is 3000 [1 / m] or less; Mounting paper for skin packs.

2. The paper substrate contains a sizing agent, The content of the sizing agent in the paper base material is 0.03 to 0.60 parts by mass per 100 parts by mass of the pulp constituting the paper base material. The skin pack mount according to claim 1.

3. The content of the sizing agent in the paper base material is 0.25 to 0.40 parts by mass per 100 parts by mass of the pulp constituting the paper base material. The skin pack mount according to claim 2.

4. The skin pack mount according to claim 1, wherein the skin pack mount has a lateral breaking elongation of 5.5 to 7.5%, as measured in accordance with JIS P 8113:2006.

5. The skin pack mount according to claim 1, wherein the paper base material has a disintegrated freeness of 350 to 600 mL.

6. The skin pack mount according to claim 1, wherein the kink index of the pulp constituting the paper base material is 1800 to 2700 [1 / m].

7. The skin pack mount according to claim 1, wherein the paper base material is a laminate having, in order from the surface in contact with the thermoplastic resin layer, a paper base material layer A, an adhesive layer, and a paper base material layer B.

8. The skin pack liner according to claim 7, wherein the ratio of the kink index of the pulp constituting the paper base layer A to the kink index of the pulp constituting the paper base layer B (kink index of paper base layer A / kink index of paper base layer B) is 1.00 to 1.

20.

9. A skin pack comprising the skin pack mount according to any one of claims 1 to 8, a storage item, and a resin film, A skin pack packaging body, in which the item to be contained is contained between the skin pack backing and the resin film.

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