Laminate, and packaging paper, packaging bag, and packaging body made of the laminate

Abstract

To provide a laminate comprising a paper base material and a thermoplastic resin layer, which allows easy opening of a package made of the laminate. [Solution] 180g / m 2 and a thermoplastic resin layer, wherein the paper substrate has a formation index of less than 20.

Description

[Technical Field]

[0001] The present invention relates to a paper-based laminate comprising a thermoplastic resin layer. [Background technology]

[0002] Paper-based laminates with thermoplastic layers are used in a variety of applications, for example, a thermoplastic layer on paperboard is used in the production of paper cups.

[0003] Furthermore, paper-based laminates containing thermoplastic resins are also used to package various items such as tissue paper and paper towels. For example, Patent Document 1 discloses a sanitary paper packaging bag made of a laminate having an extruded laminate layer of thermoplastic resin on a paper base material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-102394 Summary of the Invention [Problem to be solved by the invention]

[0005] A paper-based laminate having a thermoplastic resin layer is formed into a packaging bag by, for example, heat sealing and used to package various items. Such packaging bags usually have an opening such as a perforation, and when both sides of the opening are pushed apart with fingers or the like, the opening breaks, allowing the packaging bag to be opened. The packaged item can then be removed from the packaging bag through the opening formed by the opening.

[0006] When opening a packaging bag, if the strength of the tearing portion of the packaging bag is excessively high, a large force is required to open the packaging bag, which can make it difficult to open. Therefore, it is preferable that the tearing portion of the packaging bag can be opened with little force.

[0007] An object of the present invention is to provide a laminate comprising a paper base material and a thermoplastic resin layer, which allows a packaging bag made of the laminate to be easily opened. [Means for solving the problem]

[0008] After extensive research, the inventors discovered that in a laminate comprising a paper base material and a thermoplastic resin layer, using a paper base material with a formation index of less than a predetermined value makes it easier to open a packaging bag made of the laminate, and thus completed the present invention.

[0009] A first aspect of the present invention is 180g / m 2 a paper substrate having a basis weight of less than thermoplastic resin layer A laminate comprising: The laminate has a paper substrate formation index of less than 20.

[0010] The thickness of the thermoplastic resin layer is preferably less than 100 μm.

[0011] The oxygen permeability of the laminate of the present invention is 10.0 cc / (m 2 It is preferable that the temperature is greater than 1000°C (days).

[0012] The water vapor permeability of the laminate of the present invention is 20.0 g / (m 2 It is preferable that the temperature is greater than 100°C (day).

[0013] The laminate of the present invention preferably has an air resistance of 5000 seconds or less.

[0014] A second aspect of the present invention is The present invention relates to a wrapping paper comprising the laminate of the first aspect of the present invention.

[0015] A third aspect of the present invention is The present invention relates to a packaging bag made of the packaging paper of the second aspect of the present invention.

[0016] A fourth aspect of the present invention is The packaged item, and The packaging bag according to the third aspect of the present invention, which contains the packaged item. The present invention relates to a packaging body comprising:

[0017] In the fourth aspect of the present invention, the packaging bag is preferably heat-sealed. [Effects of the Invention]

[0018] The laminate of the present invention can make it easy to open a package made of the laminate, that is, the laminate of the present invention can provide a packaging bag that is easy to open.

[0019] The wrapping paper of the present invention can also make it easier to open a package made of the wrapping paper.

[0020] The packaging bag of the present invention is easy to open, and therefore requires less force to open.

[0021] Furthermore, the package of the present invention is also easy to open, so that the packaged items can be removed with less force.

[0022] In this way, the present invention can provide a packaging bag or a package that is easy to open. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a diagram showing an embodiment of a packaging body of the present invention. [Figure 2] 1 is an enlarged cross-sectional view of one embodiment of a laminate of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] [Laminate] A first aspect of the present invention is 180g / m 2 a paper substrate having a basis weight of less than thermoplastic resin layer A laminate comprising: The laminate has a paper substrate formation index of less than 20.

[0025] [Paper base material] The laminate of the present invention includes a paper substrate. There may be a plurality of paper substrates, but it is preferable to use one paper substrate in order to reduce the overall layer thickness.

[0026] The paper base weight (measurement method: JIS P 8124

[2011] ) is 180 g / m 2 Less than 160 g / m 2 Less than 140 g / m 2 Less than 120 g / m is more preferable. 2 More preferably, less than 100 g / m 2 It is even more preferable that the basis weight of the paper substrate is less than 10 g / m. By reducing the basis weight of the paper substrate, the thickness of the paper substrate can be reduced. This can increase the flexibility of the paper substrate, and in turn, increase the flexibility of the laminate of the present invention. On the other hand, in terms of ease of production, the basis weight of the paper substrate is 10 g / m. 2 More than 20g / m is preferable. 2 More preferably, 30 g / m 2 Therefore, the basis weight of the paper substrate is 10 g / m 2 ~180g / m 2 Less than 10 g / m is preferable. 2 ~160g / m 2 Less than 20 g / m is more preferable. 2 ~140g / m 2 Even more preferably less than 20 g / m 2 ~120g / m 2 Even more preferably less than 30 g / m 2 ~100g / m 2 Even more preferred is less than 10 ...

[0027] The thickness of the paper substrate (measurement method: JIS P 8118

[2014] ) is preferably 300 μm or less, more preferably 250 μm or less, and even more preferably 200 μm or less. The thickness of the paper substrate is preferably 20 μm or more, more preferably 30 μm or more, and even more preferably 40 μm or more. Therefore, the thickness of the paper substrate is preferably 20 μm to 300 μm, more preferably 30 μm to 250 μm, and even more preferably 40 μm to 200 μm.

[0028] The raw material for the paper substrate is not particularly limited, and examples thereof include natural fibers such as cotton, wood pulp, and wool, recycled fibers such as rayon, and synthetic fibers made from synthetic polymers such as vinylon, nylon, polyester, polyethylene, polypropylene, and acrylic. These fibers may be used alone or may be mixed and composited.

[0029] The raw material for the paper substrate is preferably wood pulp, and virgin wood pulp, recycled paper pulp, or a mixture thereof can be used. Examples of wood pulp that can be used include softwood pulp such as NBKP (softwood bleached kraft pulp) and NUKP (softwood unbleached pulp), hardwood pulp such as LBKP (hardwood bleached kraft pulp) and LUKP (hardwood unbleached pulp), and mixtures of softwood pulp and hardwood pulp.

[0030] The type of paper substrate is not particularly limited, and various types of paper can be used, but crepe paper is preferred. Crepe paper has numerous wrinkles and therefore has excellent stretchability. Therefore, by using crepe paper as the paper substrate, the packaging bag made of the laminate of the present invention can have high deformability. In particular, by using crepe paper as the paper substrate, the packaging bag made of the laminate of the present invention has excellent stretchability and improves its ability to follow deformations caused by external forces, thereby preventing the packaging bag from tearing.

[0031] In the present invention, the paper substrate has a formation index of less than 20.

[0032] The "Formation Index" is a measure of the uniformity of the fiber structure of paper. A higher Formation Index means better formation, i.e., a more uniform distribution of fibers in the paper.

[0033] A method for determining the formation index is described in US Pat. No. 6,440,267, which is incorporated herein by reference.

[0034] Specifically, the formation index can be measured by quantifying the fluctuations in the amount of transmitted light using a point light source drum scan optical analyzer, and specifically, the formation index can be measured using the "3D Sheet Analyzer" manufactured by M / K Systems Co., Ltd. In this measurement, the light source intensity is automatically calibrated according to the paper thickness, and it is known that the evaluation can be made regardless of differences in basis weight, etc.

[0035] In actual measurements, the paper substrate is A4 size and wrapped around the device so that the paper substrate does not float. Then, the formation index is measured based on transmitted light at measurement range 1 (standard sensitivity) and a light source aperture of 1.5 mm. The specific formation index is calculated as follows, with the peak class P set to 32. The measurement area is 10 cm x 10 cm. A = P / (N 100) A: Formation index P: Number of peaks (number of transmitted light intensity classes) N: The number of classes in which 0.1% or more of the pixels are distributed + the number of the class with the largest number of counts less than 0.1%, rounded to the nearest tenths place

[0036] A low formation index means that the fiber distribution in the paper is more uneven, with relatively many areas with excess or insufficient fiber. Therefore, a low formation index results in relatively many variations in the density, thickness, etc. of the paper. Furthermore, the strength of the paper is reduced in areas with insufficient fiber.

[0037] It is generally recognized that a more uniform fiber distribution in paper is preferable, and that paper with good formation, i.e., a high formation index, is preferred.

[0038] However, in the present invention, a paper base material with poor formation, i.e., a low formation index, is used. Paper with poor formation has weak interfiber bonds in areas with low density, thickness, etc., and is relatively prone to tearing. Therefore, if an opening section such as a perforation is formed in a packaging bag made of the laminate of the present invention, the opening section opens from that section, so less force is required to open the bag.

[0039] This effect is not limited to perforations, but also works when other known easy-open processing methods are used, such as notches, microslits made by laser processing, etc. Even if the package is not easy-open, it can be opened with less force by using paper with poor texture.

[0040] The formation index of the paper base is preferably 18 or less, more preferably 16 or less, even more preferably 14 or less, and even more preferably 12 or less.

[0041] The formation index of a paper base material can be controlled by known methods, for example, by appropriately adjusting the selection of pulp, papermaking conditions, etc. Specifically, the formation index can be controlled by appropriately adjusting the mixing ratio of softwood pulp and hardwood pulp, the selection of tree species, the degree of beating, the papermaking speed during papermaking, the suction conditions, the jet wire ratio in the wire part, adjustment of the wire shaker, tension, the use of dandy rolls, press pressure, etc.

[0042] [Thermoplastic resin layer] The laminate of the present invention includes a thermoplastic resin layer. The number of thermoplastic resin layers is not particularly limited, and a plurality of thermoplastic resin layers may be present, but the number of thermoplastic resin layers is preferably one or two. By limiting the number of thermoplastic resin layers to one or two, the thickness of the laminate can be reduced.

[0043] The thermoplastic resin layer does not need to be present over the entire surface of the paper substrate, but may be present over at least a portion of the surface (for example, an edge), but it is preferable that the thermoplastic resin layer be present over the entire surface of the paper substrate.Furthermore, it is preferable that the thermoplastic resin layer be present on one surface of the paper substrate, whether it is a single layer or multiple layers.

[0044] When a plurality of thermoplastic resin layers are present, the plurality of thermoplastic resin layers are preferably adjacent to each other.

[0045] Since the laminate of the present invention includes a thermoplastic resin layer, a packaging bag can be easily produced by melting and heat-sealing the thermoplastic resin layer.

[0046] The thickness of the thermoplastic resin layer is not particularly limited, but can be, for example, less than 100 μm.

[0047] The thickness of the thermoplastic resin layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1.0 μm or more. On the other hand, the thickness of the thermoplastic resin layer is preferably 90 μm or less, more preferably 80 μm or less, and even more preferably 70 μm or less. That is, the thickness of the thermoplastic resin layer is preferably 0.1 μm to 90 μm, more preferably 0.5 μm to 80 μm, and even more preferably 1.0 μm to 70 μm.

[0048] When multiple thermoplastic resin layers are present, the total thickness of the thermoplastic resin layers is preferably 0.2 μm or more, more preferably 1.0 μm or more, and even more preferably 2.0 μm or more. On the other hand, the total thickness of the thermoplastic resin layers is preferably 180 μm or less, more preferably 160 μm or less, and even more preferably 140 μm or less. That is, the total thickness of the thermoplastic resin layers is preferably 0.2 μm to 180 μm, more preferably 1.0 μm to 160 μm, and even more preferably 2.0 μm to 140 μm.

[0049] (thermoplastic resin) The thermoplastic resin layer contains at least one thermoplastic resin, and a single type of thermoplastic resin may be used, or multiple types of resins may be used in combination.

[0050] The type of thermoplastic resin is not particularly limited, and examples thereof include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polylactic acid, polyamides such as nylon, polyvinyl chloride, polyvinylidene chloride, poly(meth)acrylate, etc. It is preferable that the thermoplastic resin layer contains polyolefin.

[0051] The polyolefin is made of at least one olefin having 2 to 10 carbon atoms. Two or more olefins may be used in combination. Specific examples of the olefin include ethylene, propylene, and α-olefin.

[0052] Examples of polyolefins include homopolymers or copolymers of ethylene, homopolymers or copolymers of propylene, homopolymers or copolymers of butene, etc. Random or block copolymers of ethylene and propylene may also be used.

[0053] The polyolefin is preferably an ethylene homopolymer or copolymer. The ethylene copolymer is preferably a copolymer of ethylene and propylene and / or an α-olefin, more preferably a copolymer of ethylene and an α-olefin. The α-olefin includes those having 3 to 20 carbon atoms, preferably 3 to 8 carbon atoms, and specific examples include 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, and vinylcyclohexane, with 1-hexene being preferred. The polyolefin is particularly preferably a copolymer of ethylene and 1-hexene, or a copolymer of ethylene, propylene, and 1-hexene.

[0054] The polyolefin is preferably one synthesized using a metallocene catalyst, more preferably one synthesized by a gas phase method. Examples of polyolefins synthesized using a metallocene catalyst include Kernel KF260T, KF270, KF271, KF282, KF283, KF360T, KF370, KF380, KC452T, KC570S, KC580S, KC573, KC577T, KS240T, KS340T, KS260, KS560T, KS571, and KJ640T manufactured by Japan Polyethylene Corporation. Examples of those synthesized by a gas phase method using a metallocene catalyst include Harmolex NF324A, NF375B, NF366A, NF384A, NF444A, NF464A, NC564A, NF325N, NF464N, NF444N, NH645A, NH745N, NH845N, and NJ744N manufactured by Japan Polyethylene Corporation, and Evolue SP0510, SP1020, SP1520, SP1510, SP2020, and SP2320 manufactured by Prime Polymer Corporation.

[0055] The thermoplastic resin layer preferably contains a thermoplastic resin having a melting temperature (by DSC method) of 80°C or higher as measured according to JIS K7121. More preferably, the thermoplastic resin contained in the thermoplastic resin layer consists solely of a thermoplastic resin having a melting temperature (by DSC method) of 80°C or higher as measured according to JIS K7121. Even more preferably, the thermoplastic resin having a melting temperature (by DSC method) of 80°C or higher as measured according to JIS K7121 is the polyolefin. The melting temperature (by JIS K7121) of the thermoplastic resin is more preferably 85°C or higher, even more preferably 90°C or higher, even more preferably 95°C or higher, and even more preferably 100°C or higher.

[0056] When the laminate of the present invention includes a thermoplastic resin layer containing a thermoplastic resin having the above-mentioned specific melting temperature, a packaging bag manufactured using the laminate has excellent strength and can prevent tearing of the packaging bag in areas other than the opening portion, thereby maintaining the packaging of the packaged item in good condition.

[0057] It is more preferable that the thermoplastic resin layer contains a thermoplastic resin having a melting temperature (by DSC method) of 110°C or higher as measured in accordance with JIS K7121. It is even more preferable that the thermoplastic resin contained in the thermoplastic resin layer consists solely of a thermoplastic resin having a melting temperature (by DSC method) of 110°C or higher as measured in accordance with JIS K7121. It is even more preferable that the thermoplastic resin having a melting temperature (by DSC method) of 110°C or higher as measured in accordance with JIS K7121 is a polyolefin. Examples of such polyolefins include HARMOLEX NF324A, NF375B, NF366A, NF384A, NF444A, NF464A, NC564A, NF325N, NF464N, NF444N, NH645A, NH745N, NH845N, and NJ744N manufactured by Japan Polyethylene Corporation, and EVOLUE SP0510, SP1020, SP1520, SP1510, SP2020, and SP2320 manufactured by Prime Polymer Co., Ltd. The melting temperature of the thermoplastic resin measured according to JIS K7121 is more preferably 115°C or higher, and even more preferably 120°C or higher. In this case, the relatively high melting temperature of the thermoplastic resin can particularly improve the tear strength of the packaging bag made of the laminate of the present invention.

[0058] The amount of thermoplastic resin can be, for example, in the range of 50% by weight to 100% by weight, preferably 60% by weight to 99% by weight, more preferably 70% by weight to 97% by weight, and even more preferably 80% by weight to 95% by weight, based on the total weight of the thermoplastic resin layer.

[0059] (lubricant) The thermoplastic resin layer preferably contains a lubricant. A single type of lubricant may be used, or multiple types of lubricants may be used in combination.

[0060] Any type of lubricant, such as inorganic, organic, or inorganic / organic composite lubricant, can be used. In terms of compatibility with thermoplastic resins, organic lubricants are preferred. Examples of organic lubricants include fatty acid amides, fatty acids, fatty acid esters, and waxes, with fatty acid amides being preferred.

[0061] Examples of fatty acid amides include unsaturated fatty acid amides such as oleic acid amide and erucic acid amide, saturated fatty acid amides such as behenic acid amide, stearic acid amide, palmitic acid amide, myristic acid amide, lauric acid amide, caprylic acid amide and capric acid amide, and combinations thereof. Erucic acid amide is preferred.

[0062] The amount of lubricant is not particularly limited, but can be, for example, in the range of 0.1% by weight to 1.0% by weight, preferably 0.2% by weight to 0.8% by weight, and even more preferably 0.3% by weight to 0.6% by weight, based on the total weight of the thermoplastic resin layer.

[0063] In the present invention, a plurality of thermoplastic resin layers may be present, and the thermoplastic resin layer forming the inner surface of the packaging bag may contain a lubricant. It is preferable that the plurality of thermoplastic resin layers are adjacent to each other. In this case, by not incorporating a lubricant into the thermoplastic resin layer that does not form the inner surface of the packaging bag and that comes into contact with the paper substrate, it is possible to avoid the influence of the lubricant on the adhesion between the paper substrate and the entire thermoplastic resin layer, and for example, it is possible to avoid a decrease in the adhesion between the paper substrate and the entire thermoplastic resin layer due to the lubricant.

[0064] (Other ingredients) The thermoplastic resin layer may contain any additives, such as various organic or inorganic fillers, tackifiers, antioxidants, anti-fogging agents, various organic or inorganic pigments, flame retardants, crosslinking agents, and ultraviolet protection agents.

[0065] [Other layers] The laminate of the present invention can include layers other than the paper substrate and the thermoplastic resin, for example, an optional intermediate layer such as an adhesive layer between the paper substrate and the thermoplastic resin layer. Also, an optional layer such as a protective layer or a printed layer can be provided on the surface of the paper substrate opposite the surface facing the thermoplastic resin. However, in order to reduce the thickness of the laminate and increase the deformability of the laminate, it is preferable that the laminate consists of only the paper substrate and the thermoplastic resin layer.

[0066] [Gas barrier properties] The laminate of the present invention does not have to have gas barrier properties, for example, the laminate of the present invention may be permeable to oxygen and / or water vapor.

[0067] When a gas barrier layer is coated or laminated onto a paper substrate to improve gas barrier properties, the thickness of the laminate increases, which in turn increases its stiffness, reducing processability and usability, increasing the cost of manufacturing the laminate, and the presence of the gas barrier layer also increases the environmental load.

[0068] The oxygen permeability of the laminate of the present invention is 10.0 cc / (m 2 ·day·atom), and preferably more than 20.0cc / (m 2 ·day·atom), and more preferably 30.0cc / (m 2 The oxygen permeability can be measured in accordance with JIS K 7126-1 (differential pressure method) under atmospheric pressure, a temperature of 23°C, and a relative humidity of 50%.

[0069] The water vapor permeability of the laminate of the present invention is 20.0 g / (m 2 ·day), and more than 30.0 g / (m 2 ·day), and more preferably 40.0 g / (m 2 The water vapor permeability can be measured in accordance with JIS Z 0208:1976 (cup method) Method B (temperature 40°C ± 0.5°C, relative humidity 90% ± 2%) by positioning the paper laminate so that the resin layer is on the inner side (low humidity side).

[0070] The air resistance of the laminate of the present invention is preferably 5000 seconds or less, more preferably 2000 seconds or less, and even more preferably 1000 seconds or less. The air resistance (Oken method) can be measured in accordance with JIS P8117:2009 under atmospheric pressure, a temperature of 23°C, and a relative humidity of 50%.

[0071] When the laminate of the present invention is gas permeable, it can be suitably used for packaging medical instruments, vegetables and fruits, prepared foods, boxed lunches, and the like.

[0072] [Method for manufacturing laminate] The method for producing the laminate of the present invention is not particularly limited, and can be, for example, by integrating a paper substrate and a thermoplastic resin layer by extrusion lamination of a thermoplastic resin, applying and drying an aqueous emulsion or aqueous dispersion containing thermoplastic resin particles onto the paper substrate, or integrating a thermoplastic resin film and a paper substrate with an adhesive. The method of integrating a paper substrate and a thermoplastic resin layer by extrusion lamination is preferred. That is, the thermoplastic resin is preferably an extrusion coating layer. Another preferred method is to apply an aqueous emulsion or aqueous dispersion containing thermoplastic resin particles onto the paper substrate and dry it. If necessary, a protective layer, a printing layer, etc. can be formed by applying and drying a composition containing components for a protective layer, a printing layer, etc. to the surface of the paper substrate and / or the thermoplastic resin layer.

[0073] The tensile strength (JIS P8113) of the laminate of the present invention at 23°C and a relative humidity of 50% in the MD is preferably 1.1 kN / m to 10.0 kN / m, more preferably 1.2 kN / m to 8.0 kN / m, and even more preferably 1.3 kN / m to 6.0 kN / m, and the tensile strength of the laminate of the present invention at 23°C and a relative humidity of 50% in the CD is preferably 0.5 kN / m to 5.0 kN / m, more preferably 0.6 kN / m to 4.0 kN / m, and even more preferably 0.7 kN / m to 3.0 kN / m.

[0074] The tear strength (JIS P8116) of the laminate of the present invention at 23°C and 50% relative humidity is preferably 500 mN or more, and more preferably 500 mN or more in both the MD and CD. When the tear strength of the laminate of the present invention at 23°C and 50% relative humidity is 500 mN or more, a packaging bag made of the laminate is particularly resistant to tearing in areas other than the opening portion, and a package made of the packaging bag has particularly excellent packaging stability. The tear strength of the laminate of the present invention at 23°C and 50% relative humidity is more preferably 530 mN or more in the MD, and even more preferably 550 mN or more. The tear strength of the laminate of the present invention at 23°C and 50% relative humidity is more preferably 560 mN or more in the CD, and even more preferably 580 mN or more.

[0075] The laminate of the present invention has an elongation (JIS P8113) in the MD direction at 23°C and a relative humidity of 50% of preferably 0.5% to 10.0%, more preferably 1.0% to 9.0%, and even more preferably 1.5% to 8.0%, and in the CD direction at 23°C and a relative humidity of 50% of preferably 2.0% to 8.0%, more preferably 3.0% to 7.0%, and even more preferably 4.0% to 6.0%.

[0076] The burst strength (JIS P8112) of the laminate of the present invention at 23° C. and a relative humidity of 50% is preferably 70 kPa to 400 kPa, more preferably 80 kPa to 380 kPa, and even more preferably 90 kPa to 360 kPa.

[0077] The thickness of the laminate of the present invention (measurement method: JIS P 8118

[2014] ) is preferably 30 μm to 350 μm, more preferably 50 μm to 300 μm, and even more preferably 70 μm to 250 μm.

[0078] The basis weight of the laminate of the present invention is 20 g / m 2 ~200g / m 2 is preferred, and 30 g / m 2 ~190g / m 2 More preferably, 40 g / m 2 ~180g / m 2 is even more preferred.

[0079] The density of the laminate of the present invention is 0.40 g / cm 3 ~1.00g / cm 3 is preferred, and 0.50 g / cm 3 ~0.90g / cm 3 More preferably, 0.60 g / cm 3 ~0.80g / cm 3 is even more preferred.

[0080] [Application] The laminate of the present invention can be used for various purposes, and is preferably used for packaging purposes.

[0081] Another aspect of the present invention is A packaging paper made of the above laminate. A packaging bag made of the above packaging paper. and A package including an item to be packaged and the above-mentioned packaging bag for containing the item to be packaged. The packaging body of the present invention is capable of enclosing an item to be packaged in a packaging bag.

[0082] It should be noted that containers such as paper cups that cannot enclose the packaged item are not packaging bags in the present invention.

[0083] The packaging paper of the present invention has a paper base material and a thermoplastic resin layer, and is heat-sealable. Therefore, packaging bags can be produced by heat-sealing the packaging paper of the present invention. If necessary, a composition containing components for a protective layer, a printed layer, etc. can be applied to the surface of the paper base material and / or the thermoplastic resin layer of the packaging paper of the present invention and dried to form a protective layer, a printed layer, etc.

[0084] The packaging of the present invention uses a packaging bag made of a paper-based laminate, and therefore can address environmental issues such as environmental pollution caused by plastic remaining in the environment when discarded, compared to when packaging bags made of plastic film are used.

[0085] In particular, the paper substrate that constitutes the packaging bag is originally an organic material derived from plants and is a carbon-neutral renewable resource, which reduces the burden on the environment. Therefore, the packaging of the present invention is environmentally friendly.

[0086] When crepe paper is used as the paper substrate, the number of contact points between the packaging bag made of the laminate of the present invention and the packaged item is reduced, which also prevents the packaged item from getting caught on the packaging bag, making it easier to package packaged items such as sanitary paper, which are prone to have adverse effects when caught on the packaging bag.

[0087] The packaging bag or package of the present invention may have an opening portion that allows the packaging bag to be opened. The number of opening portions is not particularly limited, and the packaging bag or package of the present invention may have one or more opening portions.

[0088] The shape of the opening portion is not particularly limited, and any shape may be used as long as the packaging bag can be opened, but it is preferable that the opening portion has perforations.

[0089] The position of the opening part is not particularly limited, and it can be located at any position on the packaging bag. For example, if the packaging bag of the present invention is substantially box-shaped, the opening part can be provided on one of the surfaces that make up the substantially box shape, and it is preferable to provide the opening part on the top surface of the substantially box-shaped packaging bag.

[0090] An example of the packaging bag and packaging body of the present invention will be described below.

[0091] The packaging bag of the present invention is made of the laminate of the present invention. The shape of the packaging bag is not particularly limited, and it can be, for example, a non-box shape or a box shape.

[0092] In the present invention, the packaging bag is made of a laminate including a paper base material and a thermoplastic resin layer, so the strength of the packaging bag can be improved compared to when the packaging bag is made of only a paper base material.

[0093] Furthermore, in the present invention, since a paper base material is used, it is easy to make the packaging bag into a gusseted bag having a so-called "gusset."

[0094] In the packaging bag of the present invention, the thermoplastic resin layer preferably forms the inner surface of the packaging bag. The thermoplastic resin layer may form a part of the inner surface of the packaging bag, but preferably forms the entire inner surface.

[0095] In the packaging bag of the present invention, it is preferable that the paper substrate forms the outer surface of the packaging bag, which makes it easy to recognize that the packaging bag of the present invention is made of paper.

[0096] The method for producing the packaging bag or package of the present invention is not particularly limited, and for example, the planar laminate of the present invention can be transformed into a packaging bag having a storage section, and after storing the packaged item in the storage section, the opening of the storage section can be sealed by heat sealing to produce the package. Alternatively, the opening of the storage section of the packaging bag can be sealed with an adhesive or the like to produce the package. It is preferable to produce the package by sealing the opening of the storage section of the packaging bag by heat sealing.

[0097] The heat sealing temperature depends on the type of thermoplastic resin, but is preferably 80°C to 350°C, more preferably 100°C to 300°C, and even more preferably 150°C to 250°C.

[0098] The heat sealing time also depends on the type of thermoplastic resin, but is preferably 5 seconds or less, more preferably 3 seconds or less, and even more preferably 1 second or less.

[0099] In the packaging bag or package of the present invention, other layers such as a protective layer or a printed layer may be present on at least a part of the outer surface of the packaging bag, and it is preferable that an anti-slip layer be present on at least a part of the outer surface of the packaging bag. The type of anti-slip layer is not particularly limited, and for example, a member having an anti-slip function may be provided on the outer surface of the packaging bag, or unevenness having an anti-slip function may be formed on the outer surface of the packaging bag.

[0100] When a non-slip device is provided on a part of the outer surface of the packaging bag, the location of the non-slip device is not particularly limited and can be any position on the outer surface of the packaging bag, but the vicinity of the opening part is preferable. For example, when the opening part has a perforation, it is preferable to provide multiple non-slip devices on both sides of the perforation.

[0101] The anti-slip layer is preferably an anti-slip layer having a surface with anti-slip properties. The material constituting the anti-slip layer is not particularly limited, and various inorganic and / or organic materials can be used, but organic materials are preferred, and natural resins and / or synthetic resins are more preferred. The synthetic resin is preferably a synthetic resin different from the thermoplastic resin constituting the thermoplastic resin layer.

[0102] The surface shape of the anti-slip layer is not particularly limited and can be any shape such as a circle, an ellipse, a square, etc. The color of the anti-slip layer is also not particularly limited and can be white, black, various chromatic colors, or transparent.

[0103] The anti-slip layer is preferably a coating film, and more preferably a cured varnish layer. The type of varnish is not particularly limited, and a single type of varnish may be used, or multiple types of varnishes may be used in combination. For example, an organic solvent solution of a resin such as a urethane resin, an alkyd resin, or an epoxy resin may be used as the varnish. A cured varnish layer can be formed by partially applying the varnish to the outer surface of the packaging bag and drying and curing it.

[0104] When the outer surface of the packaging bag is made of a paper substrate, at least a part of the paper substrate may be impregnated with a varnish, which is then dried and cured to provide an anti-slip surface. The method of impregnation is not particularly limited, and for example, the varnish may simply be applied to the outer surface of the paper substrate.

[0105] If there is an anti-slip material on at least a portion of the outer surface of the packaging bag, for example, when the packaging bag is gripped with the fingers or the like to open the opening portion, it is possible to make the gripped portion of the packaging bag less slippery, making the opening operation even easier.

[0106] (Packaged item) The packaged items contained in the packaging of the present invention are not particularly limited, and various items such as food and paper products can be packaged, but it is preferable to package solid items other than liquids.

[0107] The type of food is not limited, and examples include snack foods such as potato chips, corn snacks, crackers, biscuits, popcorn, and chocolate snacks, which are distributed in a packaged state, as well as dried sweets such as chocolates and candies.

[0108] The type of paper product is not limited, and can be, for example, sanitary paper. Sanitary paper is paper used for the purpose of improving hygiene, and examples include disposable paper such as tissue paper (also known as facial wipes, cosmetic paper, etc.), tissue paper, paper towels (kitchen paper, etc.), toilet paper, and watting (cotton paper) (see, for example, Paper and Pulp Technology Handbook, 5th Edition, page 459, published January 30, 1992, edited and published by the Paper and Pulp Technology Association). Sanitary paper is also called sanitary paper (JIS P0001:1998).

[0109] As the sanitary paper, paper towels such as kitchen paper are preferred. Kitchen paper (including cooking paper) is mainly used in the kitchen for draining water and oil from meat, fish, vegetables, etc., as a cutting board cover, wiping dishes, wiping oil from frying pans, maintaining gas ranges and ventilation fans, wiping dirt from dining tables, etc.

[0110] Sanitary paper is porous and has the ability to absorb liquids, such as water and oil. Therefore, sanitary paper has water- and oil-absorbent properties and is suitable for use in kitchens, for example.

[0111] The fibrous material constituting the sanitary paper is not particularly limited, and examples include natural fibers such as cotton, wood pulp, and wool; recycled fibers such as rayon; and synthetic fibers made from synthetic polymers such as vinylon, nylon, polyester, polyethylene, polypropylene, and acrylic. These fibers may be used alone or in a composite mixture. Wood pulp is preferred as the fibrous material constituting the sanitary paper, and virgin wood pulp, recycled paper pulp, or a mixture of these can be used. Examples of wood pulp include softwood pulp such as NBKP (softwood bleached kraft pulp) and NUKP (softwood unbleached pulp) and hardwood pulp such as LBKP (hardwood bleached kraft pulp) and LUKP (hardwood unbleached pulp), either alone or in a suitable mixture. For example, the softwood pulp:hardwood pulp ratio can be 1 (25%):3 (75%) to 1 (50%):1 (50%).

[0112] The basis weight of the sanitary paper is not particularly limited, but the basis weight (measurement method: JIS P 8124

[2011] ) is 10 g / m 2 ~100g / m 2 is preferred, and 30 g / m 2 ~50g / m 2 The thickness of the sanitary paper is not particularly limited, but the thickness (measurement method: JIS P 8118

[2014] ) is preferably 50 μm to 300 μm, more preferably 80 μm to 200 μm.

[0113] The sanitary paper preferably has irregularities on one or both surfaces thereof. The irregularities may be present on a part of the surface of the sanitary paper or on the entire surface.

[0114] The unevenness is preferably imparted by embossing. The height of the unevenness (the vertical height from the bottom of the recess to the level of the apex of the protrusion) is not particularly limited, but may be, for example, 0.1 mm to 5 mm, or 1 mm to 3 mm.

[0115] The form of the sanitary paper is not particularly limited, and it may be in the form of a roll of long sanitary paper, but the sanitary paper is preferably in a non-roll form, more preferably in the form of a laminate of multiple flat sanitary papers, and even more preferably the flat sanitary paper is folded and stored in a packaging bag. The sanitary paper may be in the form of a single sheet (so-called 1-ply) folded in half for use, or in the form of a set of two sheets (so-called 2-ply) or three or more sheets (so-called 3-ply) laminated together and used in the same way as a single sheet.

[0116] It is preferable that the sanitary paper be contained in the packaging bag in a pop-up manner, since after the sanitary paper is removed from the packaging bag, part of the next sanitary paper is outside the packaging bag, making it easy to remove the next sanitary paper.

[0117] Preferably, the sanitary paper is not a garment such as a diaper, adult incontinence pants, or infant training pants.

[0118] [Example of packaging] Figure 1 shows an embodiment of the package of the present invention, with Figures 1(A) and 1(B) showing the front and back sides, respectively, of the embodiment of the package of the present invention, and Figure 1(C) is a cross-sectional view taken along line AA in Figure 1(A).

[0119] In Figure 1, 1 represents a package, 2 represents a packaging bag, and 3 represents a plurality of flat sanitary papers contained in a storage section within the packaging bag 2. In the example of Figure 1, the sanitary paper 3 is in the form of a laminate. In the embodiment shown in Figure 1, the packaging bag 2 is made of a laminate comprising a paper base material and a thermoplastic resin layer. In the embodiment shown in Figure 1, the packaging bag 2 is formed by heat-sealing a part (edge) of the laminate, and contains the sanitary paper 3.

[0120] A plurality of air holes 4 are formed in the packaging bag 2, and allow the air inside the packaging bag 2 to be discharged to the outside. By discharging the air inside the packaging bag 2 to the outside through the air holes 4, the volume of the packaging bag 2 can be reduced, which can make it easier to pack and transport the packaging bag 2, for example.

[0121] In the embodiment shown in Figure 1, a perforation 2-1 that can form an opening for removing the sanitary paper 3 is formed on part of the surface of the packaging bag 2, and when removing the sanitary paper 3, the perforation 2-1 is torn to form an opening, and the sanitary paper 3 can be removed to the outside through the opening.

[0122] In the embodiment shown in Fig. 1, the sanitary paper sheets 3 are stacked in a so-called pop-up style and stored inside the packaging bag 2. Therefore, when one sheet of sanitary paper sheet 3 is removed from the removal opening, part of the next sheet of sanitary paper sheet 3 can protrude from the removal opening, making it easy to remove the sanitary paper sheets 3.

[0123] Fig. 2 is an enlarged cross-sectional view of an example of a laminate that forms the packaging bag 2 of Fig. 1. In the example shown in Fig. 2, the laminate 5 includes a paper base material 5-1 and a single thermoplastic resin layer 5-2 that is present on one surface of the paper base material 5-1, and the thermoplastic resin layer 5-2 is an extrusion coating layer that is formed by extrusion laminating on the surface of the paper base material 5-1.

[0124] The laminated paper 5 shown in Figure 2 consists only of a paper base material 5-1 and a thermoplastic resin layer 5-2, with the thermoplastic resin layer 5-2 forming the inner surface and facing the sanitary paper 3 shown in Figure 1, and the paper base material 5-1 forming the outer surface.

[0125] The packaging body 1 in Figure 1 uses a packaging bag 2 made of a laminate 5 consisting of a paper base material 5-1 and a thermoplastic resin layer 5-2, so the strength of the packaging bag 2 is improved and tearing of the packaging bag 2 can be reduced compared to when a packaging bag 2 consisting only of the paper base material 5-1 is used.

[0126] Sanitary paper has high porosity due to its excellent water and oil absorption properties, and is relatively prone to fluffing. Therefore, when a paper packaging bag comes into contact with the sanitary paper, the sanitary paper tends to get caught on the packaging bag, making the packaging process difficult. However, in the packaging body 1 shown in FIG. 1, the thermoplastic resin layer 5-2 shown in FIG. 2 faces the sanitary paper 3, so during packaging, the sanitary paper 3 comes into contact with the smooth surface of the thermoplastic resin layer 5-2 and does not come into contact with the paper base material 5-1. This prevents the sanitary paper 3 from getting caught on the packaging bag 2. Therefore, the packaging body 1 can maintain the packaging of the sanitary paper 3 well and makes packaging easy.

[0127] 1, the outer surface of the packaging bag 2 is formed by a paper base material 5-1, so that it is easy to recognize from the outside that the packaging bag 2 is made of paper. [Industrial Applicability]

[0128] The present invention can provide a packaging bag or a packaging body that can be easily opened. For example, the laminate of the present invention can form a packaging bag or a packaging body that can be easily opened.

[0129] Furthermore, the laminate of the present invention can be suitably used for packaging purposes as a wrapping paper with reduced environmental impact.

[0130] The thermoplastic resin layer of the laminate or packaging paper of the present invention can be heat-sealed, making it easy to produce packaging bags or packages.

[0131] The packaging bag or package of the present invention is easy to open.

[0132] Furthermore, the packaging bag of the present invention can prevent sanitary paper, which is prone to fuzzing, from getting caught on the packaging bag, making the packaging bag of the present invention suitable for packaging sanitary paper.

[0133] The package of the present invention is easy to open and can be strong enough to resist tearing, making it suitable for storage and transportation. [Example]

[0134] The present invention will be described in more detail below using examples and comparative examples, but the scope of the present invention is not limited to the examples.

[0135] <Paper base material formation index> The formation index based on the transmitted intensity of various paper substrates was measured using a 3D sheet analyzer manufactured by M / K Systems. First, the paper substrate was A4 size and wrapped around the device so that the paper substrate did not float. Next, the transmitted light formation index was measured at measurement range 1 (standard sensitivity) and light source aperture of 1.5 mm. The specific method for calculating the formation index is as follows, with the peak class P set to 32. The measurement area was 10 cm x 10 cm. A = P / (N 100) A: Formation index P: Number of peaks (number of transmitted light intensity classes) N: The number of classes in which 0.1% or more of the pixels are distributed + the number of the class with the largest number of counts less than 0.1%, rounded to the nearest tenths place The larger the numerical value of the formation index, the better the formation.

[0136] [Example 1] Polyethylene (Harmolex manufactured by Japan Polyethylene Co., Ltd.) was extruded onto a paper substrate (50 g of unbleached kraft paper (formation index 8.0)) using an extrusion laminator, and laminated onto the paper substrate to a resin thickness of 25 μm to produce a laminate comprising a thermoplastic resin layer on the paper substrate. The laminate was formed into a bag shape using a horizontal pillow packaging machine with the thermoplastic resin layer facing inward, sanitary paper (paper towel manufactured by Tryfe Co., Ltd.) was placed inside, and the opening was sealed by heat sealing at 200°C for 1 second to produce a package. Perforations were made on the top surface of the package, and furthermore, slit-shaped air holes, each 3 mm long, were provided in two rows at 25 mm intervals on the side.

[0137] [Example 2] A package was produced in the same manner as in Example 1, except that the paper substrate was changed to 80 g of Clupak paper (formation index 8.7).

[0138] [Example 3] A package was produced in the same manner as in Example 1, except that the paper substrate was changed to 35 g of bleached glossy paper (formation index 9.1) and a thermoplastic resin layer was provided on the glossy side.

[0139] [Example 4] A package was produced in the same manner as in Example 1, except that the paper substrate was changed to 35 g of bleached glossy paper (formation index 9.6) and a thermoplastic resin layer was provided on the non-glossy side.

[0140] [Example 5] A package was produced in the same manner as in Example 1, except that the paper substrate was changed to 75 g of unbleached kraft paper (formation index 9.9).

[0141] [Example 6] A package was produced in the same manner as in Example 1, except that the paper substrate was changed to 50 g of unglazed bleached kraft paper (formation index 13.2).

[0142] [Comparative Example 1] A package was produced in the same manner as in Example 1, except that the paper substrate was changed to 70 g of unglazed bleached kraft paper (formation index 52.5).

[0143] Comparative Example 2 A package was produced in the same manner as in Example 1, except that the paper substrate was changed to 80 g of bleached glossy paper (formation index 70.2) and a thermoplastic resin layer was provided on the non-glossy side.

[0144] Comparative Example 3 A package was produced in the same manner as in Example 1, except that the paper substrate was changed to 100 g of fine paper (formation index 85.3).

[0145] [evaluation] Ten panelists evaluated the ease of opening the packages of Examples 1 to 6 and Comparative Examples 1 to 3 based on the following criteria. 5: Very easy to open 4: Easy to open 3:Can be opened 2: Somewhat difficult to open 1: Difficult to open The evaluation results were averaged, and 4 or more was given a ◎, 3 or more was given a ○, and less than 3 was given an ×. The results are shown in Table 1 below.

[0146] [Table 1]

[0147] As is clear from Table 1, when a paper base material with a formation index of less than 20 was used, the packaging bag was easy to open and could be opened with little force. Furthermore, when a paper base material with a formation index of less than 9 was used, the packaging bag was particularly easy to open and could be opened with even less force. [Explanation of symbols]

[0148] 1 package 2 packaging bag 3 Sanitary paper 4 air vents 5. Laminate 5-1 Paper base material 5-2 Thermoplastic resin layer

Claims

1. 180 g / m ２ a paper substrate having a basis weight of less than thermoplastic resin layer A laminate comprising: The paper base has a formation index of less than 20, A laminate having a tear strength of 500 mN or more at 23°C and 50% relative humidity.

2. The laminate of claim 1 , wherein the thermoplastic resin layer has a thickness of less than 100 μm.

3. Oxygen permeability is 10.0cc / (m 2 2. The laminate of claim 1, wherein the surface tension is greater than 1 / day / atom.

4. Water vapor permeability is 20.0g / (m 2 2. The laminate of claim 1, wherein the temperature is greater than 100°C.

5. 2. The laminate according to claim 1, having an air resistance of 5,000 seconds or less.

6. A wrapping paper comprising the laminate of claim 1.

7. A packaging bag made from the packaging paper according to claim 6.

8. The packaged item, and The packaging bag according to claim 7, which contains the packaged item. A packaging body comprising:

9. 9. The package of claim 8, wherein the packaging bag is heat sealed.

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