Packaging laminate

Abstract

To provide a novel packaging laminate capable of exhibiting excellent heat sealing performance with a small resin amount.SOLUTION: A packaging laminate 100 comprises a base material layer 10 and a sealant laminate 20. The sealant laminate 20 includes a first layer 22 and a second layer 24 in order from the base material layer 10 side. The first layer 22 contains first sealant resin and calcium carbonate. The second layer 24 contains second sealant resin. The content rate of calcium carbonate in the second layer 24 is lower than that of calcium carbonate in the first layer 22.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a packaging laminate. [Background technology]

[0002] Conventionally, plastic sheets have been widely used for packaging purposes. Packages made from such sheets have many advantages, such as excellent water resistance, and are therefore used as alternative materials to paper packaging containers. On the other hand, from an environmental standpoint, it is considered necessary to reduce the use of petroleum-based resources as much as possible. From this standpoint, calcium carbonate has been mixed into plastic sheets.

[0003] Patent Document 1 discloses a household garbage bag that is characterized in that 10% by weight of linear low-density polyethylene, 15% by weight of low-density polyethylene, and 75% by weight of calcium carbonate are mixed and stirred at high temperature after injecting a solvent, and then injection molded in a reduction molding machine to produce a resin composition, and then 30% by weight of this resin composition and 70% by weight of high-density polyethylene are mixed and stirred in a dryer at 80°C, and molded in a polyethylene blowing film molding machine.

[0004] Patent Document 2 discloses a sheet that is made of a resin composition containing a thermoplastic resin and inorganic particles in a ratio of 85:15 to 20:80 and further containing a polyolefin resin having a hydrophilic group, and that has an elastic modulus of 1,000 MPa or more.

[0005] Patent Document 3 discloses a polyethylene resin composition in which calcium carbonate is blended with a polyethylene resin, wherein at least a part of the calcium carbonate in the polyethylene resin composition is calcium carbonate having an average particle size of 0.1 to 5.0 μm derived from an EVA-based masterbatch containing calcium carbonate and an ethylene-vinyl acetate resin, and the proportion of calcium carbonate derived from the EVA-based masterbatch to the total content of calcium carbonate in the polyethylene resin composition is 30 mass% or more. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-114301 A [Patent Document 2] JP 2018-48229 A [Patent Document 3] Patent Publication No. 2022-6831 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention provides a novel packaging laminate which can provide good heat sealability with a small amount of resin. [Means for solving the problem]

[0008] As a result of intensive research, the present inventors have found that the above problems can be solved by the following means, and have completed the present invention. That is, the present invention is as follows: <Aspect 1> A substrate layer and a sealant laminate, the sealant laminate has, in order from the base layer side, a first layer and a second layer, the first layer comprises a first sealant resin and calcium carbonate; the second layer contains a second sealant resin, and the content of calcium carbonate in the second layer is lower than the content of calcium carbonate in the first layer; Packaging laminates. <Aspect 2> The packaging laminate according to aspect 1, wherein the calcium carbonate content in the second layer is 1 / 10 or less of the calcium carbonate content in the first layer. <Aspect 3> The packaging laminate according to aspect 1 or 2, wherein the calcium carbonate content is greater than 50 mass% based on the mass of the packaging laminate. <Aspect 4> The packaging laminate according to any one of Aspects 1 to 3, wherein the content of the calcium carbonate is 60 to 75 mass % relative to the mass of the first layer. <Aspect 5> The packaging laminate according to any one of Aspects 1 to 4, wherein the content of the calcium carbonate is 55 to 70 mass% relative to the mass of the sealant laminate. <Aspect 6> The packaging laminate according to any one of Aspects 1 to 5, wherein the first and second sealant resins are both polyethylene-based resins. <Aspect 7> The packaging laminate according to any one of Aspects 1 to 6, wherein the sealant laminate has a third layer between the base layer and the first layer, and the third layer contains a third sealant resin and calcium carbonate. <Aspect 8> The packaging laminate according to Aspect 7, wherein the polyethylene resin has a tensile breaking stress of 13 N or more as measured in accordance with JIS K7161-1:2014. <Aspect 9> The packaging laminate according to aspect 7 or 8, wherein the polyethylene resin has a flexural modulus of elasticity of 170 MPa or more as measured in accordance with JIS K7171:2016. A packaging bag having the packaging laminate according to any one of Aspects 1 to 9. <Aspect 11> The packaging bag described in Aspect 10, wherein the calcium carbonate content is greater than 50 mass% relative to the mass of the packaging bag. <Aspect 12> A packaging bag containing contents, comprising the packaging bag described in aspect 10 or 11, and contents stored in the packaging bag. Effect of the Invention

[0009] According to the present invention, it is possible to provide a novel packaging laminate which can obtain good heat sealability with a small amount of resin. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a side cross-sectional view of the packaging laminate of the present invention. [Diagram 2] FIG. 2 is a diagram comparing the packaging laminate of the present invention with a conventional packaging laminate. [Diagram 3] FIG. 3 is a schematic diagram of another conventional packaging laminate. [Figure 4] Fig. 4(a) is a rear view of a pillow bag for evaluating the suitability for bag making, and Fig. 4(b) is a cross-sectional view taken along line bb in Fig. 4(a). [Diagram 5] Fig. 5(a) is a front view of a laminate for evaluation of heat seal strength, and Fig. 5(b) is a side cross-sectional view taken along line bb in Fig. 5(a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <<Packaging laminate>> The packaging laminate 100 of the present invention is A substrate layer 10 and a sealant laminate 20 are included. The sealant laminate 20 has, in order from the base layer 10 side, a first layer 22 and a second layer 24, the first layer 22 includes a first sealant resin and calcium carbonate; The second layer 24 contains a second sealant resin, and the calcium carbonate content in the second layer 24 is lower than the calcium carbonate content in the first layer 22 .

[0012] The present inventors have found that by using a sealant laminate 20 having a first layer 22 containing a first sealant resin and calcium carbonate, and a second layer 24 having a calcium carbonate content lower than the calcium carbonate content in the first layer 22, as shown in FIG. 2(a), it is possible to obtain sufficient heat seal strength without causing sealing defects with a small amount of resin.

[0013] In contrast, when the sealant layer 20a made only of resin in the conventional packaging laminate 200a shown in FIG. 2(b) is simply changed to a sealant layer 20b containing calcium carbonate throughout, as shown in FIG. 3(a), in order to reduce the amount of resin used, sufficient heat seal strength may not be obtained.

[0014] Furthermore, as shown in FIG. 3(b), when the amount of resin used is reduced by using a thinner sealant layer 20c, sealing defects such as pinholes may occur during heat sealing, particularly at the intersections of the seal parts, such as the back seal part of a pillow bag.

[0015] The calcium carbonate content in the packaging laminate of the present invention may be more than 50% by mass, 55% by mass or more, or 60% by mass or more, and may be 70% by mass or less, or 65% by mass or less, based on the mass of the packaging laminate.

[0016] Each component of the present invention will now be described.

[0017] <Base material layer> The substrate layer may be composed of a thermoplastic resin having excellent impact resistance, abrasion resistance, etc., such as a vinyl resin, a polyester resin, a polyamide resin, a polypropylene resin, etc. The substrate layer may be a single layer or a laminate.

[0018] Examples of vinyl resins include polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polychlorotrifluoroethylene, polytetrafluoroethylene, and polyacrylonitrile (PAN).

[0019] Examples of polyester resins include polyethylene terephthalate (PET) and polybutylene terephthalate.

[0020] Examples of polyamide resins include nylons such as Nylon (registered trademark) 6 and Nylon MXD6.

[0021] As the polypropylene-based resin, the resins mentioned in relation to the first layer of the sealant laminate can be used.

[0022] The thickness of the base material layer is preferably 7 μm or more, or 10 μm or more, from the viewpoint of the mechanical strength of the packaging laminate, and is preferably 55 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less, from the viewpoint of increasing the calcium carbonate content in the entire packaging laminate.

[0023] The resin constituting the base layer may be one type or a blend of two or more types, and additives for imparting functionality, etc. may be blended as necessary.

[0024] The base layer is preferably made of a preformed film. The film to be the base layer may be a film formed from the above-mentioned resin or the like, and may be unstretched or uniaxially or biaxially stretched. Among them, a biaxially stretched film is preferable.

[0025] <Sealant laminate> The sealant laminate has, in this order from the substrate layer side, a first layer and a second layer, and the second layer has a lower calcium carbonate content than the first layer.

[0026] The content of calcium carbonate in the sealant laminate is preferably 55% by mass or more, 60% by mass or more, or 65% by mass or more, based on the mass of the sealant laminate, from the viewpoint of increasing the content of calcium carbonate in the entire packaging laminate. From the viewpoint of heat seal strength, this content is preferably 70% by mass or less.

[0027] The sealant laminate may further include a third layer between the base layer and the first layer, i.e., the sealant laminate may include, in order from the base layer side, the third layer, the first layer, and the second layer.

[0028] The sealant laminate can be produced by kneading the resin compositions constituting each layer using, for example, a batch-type kneader such as a kneader, a Banbury mixer, a mixing roll, or a conical mixer, or a continuous kneader such as a twin-screw kneader, and then molding the kneaded resin into a film by an extrusion molding method such as an inflation method or a T-die method. In producing the sealant laminate, film formation and lamination may be performed simultaneously by a co-extrusion method such as a multi-layer inflation method or a multi-layer T-die method.

[0029] (First layer) The first layer contains a first sealant resin and calcium carbonate, and is located closer to the base layer than the second layer.

[0030] The first sealant resin may be, for example, a polyolefin resin, such as a polyethylene resin or a polypropylene resin.

[0031] The polyethylene resin is a resin that contains more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of ethylene group repeating units in the main chain of the polymer, and is, for example, selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), derivatives thereof, and mixtures thereof.

[0032] The polypropylene-based resin is a resin that contains more than 50 mol%, 60 mol% or more, 70 mol% or more, or 80 mol% or more of propylene group repeating units in the polymer main chain, and examples thereof include polypropylene (PP) homopolymer, random polypropylene (random PP), block polypropylene (block PP), chlorinated polypropylene, acid-modified polypropylene, and derivatives thereof, and mixtures thereof.

[0033] When the first sealant resin is a polyethylene resin, from the viewpoint of heat seal strength, it is preferable that the tensile stress at break of this polyethylene resin according to JIS K7161-1:2014 is 13 N or more, 14 N or more, 15 N or more, 16 N or more, 17 N or more, 18 N or more, or 19 N or more. This tensile stress at break may be, for example, 100 N or less, 90 N or less, 80 N or less, 70 N or less, 60 N or less, 50 N or less, or 40 N or less.

[0034] When the first sealant resin is a polyethylene resin, the flexural modulus of this polyethylene resin according to JIS K7171:2016 is preferably 120 MPa or more, 130 MPa or more, 140 MPa or more, 150 MPa or more, 160 MPa or more, 170 MPa or more, 180 MPa or more, 190 MPa or more, 200 MPa or more, 220 MPa or more, 250 MPa or more, 280 MPa or more, or 300 MPa or more from the viewpoint of heat seal strength. This flexural modulus may be 1000 MPa or less, 900 MPa or less, 800 MPa or less, 700 MPa or less, 600 MPa or less, 500 MPa or less, or 400 MPa or less.

[0035] The content of calcium carbonate in the first layer is preferably 60% by mass or more, 65% by mass or more, or 70% by mass or more from the viewpoint of increasing the content of calcium carbonate in the entire packaging laminate, and is preferably 75% by mass or less from the viewpoint of heat seal strength.

[0036] The thickness of the first layer is preferably 25 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 45 μm or more, 50 μm or more, or 55 μm or more from the viewpoint of increasing the calcium carbonate content in the entire packaging laminate and from the viewpoint of suitability for bag making. This thickness may be 100 μm or less, 90 μm or less, 85 μm or less, 80 μm or less, 75 μm or less, 70 μm or less, or 65 μm or less.

[0037] The thickness of the first layer may be 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, or 65% or more of the total thickness of the packaging laminate, and may be 85% or less, 80% or less, 75% or less, or 70% or less.

[0038] (Second layer) The second layer contains a second sealant resin and is a layer that is present on the outer side of the first layer. When the second layer is made into a packaging bag, it can be a layer that is located on the content side. As the second sealant resin, the resins listed as the first sealant resin can be used. The second sealant resin may be the same type of resin as the first sealant resin, or may be a different type of resin. For example, both the first and second sealant resins may be polyethylene-based resins.

[0039] The calcium carbonate content in the second layer is lower than the calcium carbonate content in the first layer, and is particularly preferably 1 / 5 or less, 1 / 10 or less, 1 / 15 or less, 1 / 20 or less, 1 / 30 or less, 1 / 40 or less, or 1 / 50 or less of the calcium carbonate content in the first layer, or 0 mass%, from the viewpoint of obtaining heat seal strength.

[0040] The thickness of the second layer is preferably 5 μm or more, 7 μm or more, or 9 μm or more from the viewpoint of suitability for bag making. The thickness is preferably 20 μm or less, 17 μm or less, 15 μm or less, or 12 μm or less from the viewpoint of increasing the content of calcium carbonate in the entire packaging laminate.

[0041] The thickness of the second layer may be 5% or more, 7% or more, or 10% or more, and may be 25% or less, 22% or less, 20% or less, 15% or less, or 13% or less of the total thickness of the packaging laminate.

[0042] (Third layer) The third layer is an optional layer that contains a third sealant resin and calcium carbonate and is present closer to the base layer than the first layer. The third sealant resin may be the same resin as the first sealant resin. The third sealant resin may be a resin of the same type as the first sealant resin, or may be a resin of a different type. For example, both the first and third sealant resins may be polyethylene-based resins.

[0043] The calcium carbonate content in the third layer is preferably 60% by mass or more, 65% by mass or more, or 70% by mass or more, from the viewpoint of increasing the calcium carbonate content in the entire packaging laminate. This content is preferably 80% by mass or less, or 75% by mass or less, from the viewpoint of heat seal strength. This content may be the same as the calcium carbonate content in the first layer. In particular, it is preferable that the third layer is composed of the same resin composition as the first layer, from the viewpoint of ease of production.

[0044] The thickness of the third layer is preferably 5 μm or more, 7 μm or more, or 9 μm or more from the viewpoint of increasing the content of calcium carbonate in the entire packaging laminate. The thickness may be 20 μm or less, 17 μm or less, 15 μm or less, or 12 μm or less.

[0045] The thickness of the third layer may be 5% or more, 7% or more, or 10% or more, and may be 25% or less, 22% or less, 20% or less, 15% or less, or 13% or less, of the total thickness of the packaging laminate.

[0046] Other Layers The packaging laminate of the present invention may have other optional layers, such as an adhesive layer between the reinforcing layer and the base resin layer, an anchor coat layer, and a barrier layer.

[0047] As the adhesive layer, for example, a dry lamination adhesive, a hot lamination adhesive, or the like can be used.

[0048] The barrier layer may be made of a material capable of preventing moisture, organic gases, and inorganic gases from penetrating into the gas absorbing layer from the outside. Examples of the barrier layer include a single metal foil layer such as copper foil or aluminum foil, an alloy foil layer such as stainless steel foil, an inorganic vapor deposition film such as a silica vapor deposition film, an alumina vapor deposition film, or a silica-alumina binary vapor deposition film, or an organic coating film such as a polyvinylidene chloride coating film, a polychlorotrifluoroethylene coating film, or a polyvinylidene fluoride coating film.

[0049] When an inorganic vapor deposition film or an organic coating film is used as the barrier layer, the thickness of the barrier layer is preferably 100 nm or more, 200 nm or more, 300 nm or more, 500 nm or more, 700 nm or more, or 1 μm or more from the viewpoint of ensuring strength and barrier properties, and is preferably 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less from the viewpoints of reducing the overall thickness of the packaging laminate and reducing the resin content in the entire packaging laminate.

[0050] When a metal foil layer or a barrier resin layer is used as the barrier layer, the thickness of the barrier layer is preferably 7 μm or more, 10 μm or more, or 15 μm or more from the viewpoint of ensuring strength and barrier properties, and is preferably 50 μm or less, 45 μm or less, 40 μm or less, or 35 μm or less from the viewpoint of reducing the thickness of the entire packaging laminate.

[0051] 《Packaging bag》 The packaging bag of the present invention is a packaging bag having the above-mentioned packaging laminate.

[0052] In particular, the packaging bag of the present invention comprises one or more of the above-mentioned packaging laminates, One or more sheets of the packaging laminate are formed into a bag by heat-sealing a portion of the packaging laminate to another portion of the packaging laminate or to another film.

[0053] Here, the other film may be another packaging laminate or may be another film other than the packaging laminate, but it is preferable to use the other packaging laminate from the viewpoint of increasing the calcium carbonate content of the entire packaging bag.

[0054] The packaging bag of the present invention can be a content-containing packaging bag having the above-mentioned packaging bag and the content stored in the packaging bag.

[0055] The packaging bag of the present invention may be in the form of, for example, a three-side sealed bag, a four-side sealed bag, a pillow bag, a gusset bag, a standing pouch, or the like.

[0056] The calcium carbonate content in the packaging bag of the present invention may be greater than 50% by mass, 55% by mass or more, or 60% by mass or more, and may be 70% by mass or less, or 65% by mass or less, relative to the mass of the packaging bag.

[0057] <Contents> The contents are the contents stored in the packaging bag. The contents are not limited as long as they can deteriorate when exposed to the outside air, and examples of the contents include medicines, food, cosmetics, medical instruments, medical equipment, electronic parts, precision machinery, recording materials, etc. Furthermore, medicines include pharmaceutical preparations, cleaning agents, agricultural chemicals, etc. EXAMPLES

[0058] The present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these.

[0059] Comparison with and without calcium carbonate <Preparation of Packaging Laminate> Example 1 Using a coextrusion molding machine (KZW15TW-45MG-NH-2200, Technobel Co., Ltd.), a two-kind, three-layer sealant laminate was obtained by the coextrusion T-die method, having a third layer with a thickness of 10 μm, a first layer with a thickness of 60 μm, and a second layer with a thickness of 10 μm.

[0060] The third and first layers were made of 90 parts by mass of a master batch containing 80% by mass of calcium carbonate and 20% by mass of polyethylene, and 10 parts by mass of linear low-density polyethylene (PE1, density 0.925 g / cm 3 A resin composition having a kneaded strength of 20 N and a flexural modulus of 320 MPa was used. For the second layer, PE1 was used alone.

[0061] Next, a 15 μm nylon film as a base layer and the third layer of the obtained sealant laminate were laminated by dry lamination to obtain the packaging laminate of Example 1. In the dry lamination, a urethane-based two-component dry lamination adhesive was used.

[0062] Comparative Example 1 A packaging laminate of Comparative Example 1 was obtained in the same manner as in Example 1, except that the above-mentioned resin composition was used for each of the first, second, and third layers.

[0063] Comparative Example 2 A packaging laminate for Comparative Example 2 was obtained in the same manner as in Example 1, except that a resin composition kneaded with 82.8 parts by mass of the above master batch and 16.2 parts by mass of PE1 was used as the first, second, and third layers.

[0064] Comparative Example 3 A packaging laminate of Comparative Example 3 was obtained in the same manner as in Example 1, except that the above PE1 was used alone for the first, second, and third layers.

[0065] Comparative Example 4 The packaging laminate of Comparative Example 4 was obtained in the same manner as in Example 1, except that the above PE1 was formed into a 26 μm film and used instead of the sealant laminate. The thickness of this film in Comparative Example 4 was set so that it contained the same mass of PE as that contained in the sealant laminate of the Example.

[0066] <evaluation> (Bag making suitability) The bag-making suitability was evaluated by forming each packaging laminate 100 into a pillow bag 300 as shown in Figures 4(a) and (b). More specifically, the produced packaging laminate 100 was cut into a size of 420 mm x 380 mm, and the second layers were placed opposite each other to obtain a bottom seal portion 310 and a back seal portion 320 by heat sealing, thereby producing a pillow bag with outer dimensions of 200 mm x 380 mm. The heat sealing was performed using an impulse sealer (electric sealer FA-300-10W, Fuji Impulse Co., Ltd.) under conditions of a heating temperature of 1.0 seconds and a cooling temperature of 2.0 seconds.

[0067] Ageless Checker was sprayed with a spray bottle toward intersection 330 of bottom seal 310 and back seal 320 of fabricated pillow bag 300, and the intersection was left for one minute, and the appearance of the intersection was visually inspected. The evaluation criteria were as follows: A: There was no leak of the Ageless Checker at the intersection. B: There was an ageless checker leak at the intersection.

[0068] (Heat seal strength) 5(a) and (b), the second layer 24 of the same packaging laminate 100 was placed facing each other, and heat-sealed under the conditions of upper die temperature 140°C, lower die temperature 140°C, sealing time 0.5 seconds, and sealing pressure 0.2 MPa to obtain an evaluation laminate 400. The heat seal strength was measured by T-peeling in the X direction under the conditions of width 15 mm, chuck distance 50 mm, and tensile speed: 300 mm / min. The width 410A of the sealed portion 410 in the peeling direction was 10 mm, and the width 410B in the direction perpendicular to the peeling direction was 15 mm.

[0069] (Suitable for incineration) The evaluation criteria for suitability for incineration are as follows: A: The resin content is less than 50% by mass based on the mass of the packaging laminate. B: The resin content is 50% by mass or more based on the mass of the packaging laminate.

[0070] Table 1 shows the configurations and evaluation results of the examples and comparative examples.

[0071] [Table 1]

[0072] From Table 1, it can be seen that the packaging laminate of Example 1, which had a first layer containing a first sealant resin and calcium carbonate, and a second layer having a calcium carbonate content lower than the calcium carbonate content in the first layer, was good in all of bag formability, heat seal strength, and incineration suitability.

[0073] Comparison by resin type and thickness <Preparation of Packaging Laminate> The content of the master batch was adjusted so that the calcium carbonate content of each layer was the value shown in Table 1, and polyethylenes shown in Table 1 were used as the remaining resin, and the thickness of each layer was set to the thickness shown in Table 1. The packaging laminates of Examples 2 to 10 were produced in the same manner as in Example 1. Details of each polyethylene used are as follows. PE2: Linear low-density polyethylene, density 0.930g / cm 3 , tensile breaking stress 20N, bending modulus 340MPa PE3: Linear low-density polyethylene, density 0.920g / cm 3 , tensile breaking stress 14N, bending modulus 170MPa PE4: Linear low-density polyethylene, density 0.898g / cm 3 , tensile breaking stress 8N, bending modulus 50MPa PE5: Low density polyethylene, density 0.918g / cm 3, tensile breaking stress 12N, bending modulus 110MPa

[0074] <evaluation> (Heat seal strength) 5(a) and (b), the second layer 24 of the same packaging laminate 100 was placed facing each other, and heat-sealed under the conditions of upper die temperature 140°C, lower die temperature 140°C, sealing time 0.5 seconds, and sealing pressure 0.2 MPa to obtain an evaluation laminate 400. The heat seal strength was measured by T-peeling in the X direction under the conditions of width 15 mm, chuck distance 50 mm, and tensile speed: 300 mm / min. The width 410A of the seal portion 410 in the peeling direction was 10 mm, and the width 410B in the direction perpendicular to the peeling direction was 15 mm.

[0075] The configurations and evaluation results of Examples 1 to 10 are shown in Table 2.

[0076] [Table 2]

[0077] It can be seen from Table 2 that, among the examples, when PE1, PE2 and PE3 were used as the polyethylene, the heat seal strength was particularly good. PE1, PE2 and PE3 are all polyethylenes having a tensile stress of 12 N or more and a flexural modulus of 170 MPa or more.

[0078] In addition, in the examples using PE4 and PE5, as in Comparative Example 1, it can be assumed that the heat seal strength would be further reduced if layers having the same calcium carbonate content were used as the first layer and the second layer. [Explanation of symbols]

[0079] 100 Packaging laminate 10 Base material layer 20 Sealant laminate 22 First Layer 24 Second Layer 26 The Third Layer 200a Conventional packaging laminate 20a, 20b, 20c Conventional sealant layer 300 pillow bag 310 Lower seal part 320 Back seal 330 Intersection of lower seal and back seal 400 Evaluation laminate 410 Seal part 410A Width of the seal in the peeling direction 410B Width of the seal in the direction perpendicular to the peeling direction X Peeling direction

Claims

1. a substrate layer and a sealant laminate, the sealant laminate has, in order from the base layer side, a first layer and a second layer, the first layer comprises a first sealant resin and calcium carbonate; the second layer contains a second sealant resin, and the content of calcium carbonate in the second layer is lower than the content of calcium carbonate in the first layer; Packaging laminate.

2. 2. The packaging laminate according to claim 1, wherein the content of calcium carbonate in the second layer is 1 / 10 or less of the content of calcium carbonate in the first layer.

3. 3. The packaging laminate according to claim 1, wherein the content of the calcium carbonate is more than 50% by mass relative to the mass of the packaging laminate.

4. 3. The packaging laminate according to claim 1, wherein the content of the calcium carbonate is 60 to 75% by mass relative to the mass of the first layer.

5. 3. The packaging laminate according to claim 1, wherein the content of the calcium carbonate is 55 to 70% by mass relative to the mass of the sealant laminate.

6. 3. The packaging laminate according to claim 1, wherein the first and second sealant resins are both polyethylene-based resins.

7. 3. The packaging laminate according to claim 1, wherein the sealant laminate has a third layer between the base layer and the first layer, and the third layer contains a third sealant resin and calcium carbonate.

8. The packaging laminate according to claim 6, wherein the polyethylene resin has a tensile breaking stress in accordance with JIS K7161-1:2014 of 13 N or more.

9. The packaging laminate according to claim 6, wherein the polyethylene resin has a flexural modulus in accordance with JIS K7171:2016 of 170 MPa or more.

10. A packaging bag comprising the packaging laminate according to claim 1 or 2.

11. The packaging bag according to claim 10, wherein the content of the calcium carbonate is more than 50% by mass relative to the mass of the packaging bag.

12. A packaging bag containing contents, comprising the packaging bag according to claim 10 and contents stored in the packaging bag.

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