sealant film

Abstract

To provide a film and / or a packaging bag which allows the content to be easily taken out even when the content is viscous, exhibits sufficient heat sealability, and exhibits excellent easy peelability.SOLUTION: A laminate is formed by laminating a sealant film composed of a resin composition containing (a) a polypropylene-based resin, (b) a polyethylene-based resin, and (c) a silylated polyethylene resin and satisfying the following (1), (2), and (3), and at least a stretched polyamide film. (1) The contents of (a), (b), and (c) are 30-70 wt.% for (a), 10-40 wt.% for (b), and 3-30 wt.% for (c), with respect to the total amount of the resin composition. (2) The silylated polyethylene resin is represented by the following formula: CH3-(CH2)n-2-CH2-Si(CH3)2O-(-Si(CH3)2-O-)d-Si(CH3)2-CH2-(CH2)n-2-CH3 (where d is an integer of 1 or larger, and n is an integer of 100 or larger). (3) The polyethylene-based resin is a high-pressure low-density polyethylene.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a sealant film and a laminate using the same. More specifically, it relates to a sealant film with excellent liquid repellency, heat sealability, slipperiness, and blocking properties, and a laminate packaging bag using the same. [Background technology]

[0002] Plastic film packaging bags are lightweight, airtight, transparent, high-strength, and easy to handle, making them widely used for packaging solids, liquids, powders, pastes, viscous substances, and mixtures thereof, as well as foods, pharmaceuticals, and other products.

[0003] However, it is common knowledge from experience that when removing food, medicine, or other products from their packaging, liquids, pastes, or viscous substances tend to stick to the inside of the packaging, making them difficult to remove. Furthermore, discarding packaging with remaining contents can pose hygiene problems.

[0004] To address these challenges, films coated with surfactants or films with surfactants incorporated into them have been proposed (see, for example, Patent Documents 1 and 2). However, these films do not allow for easy removal of the contents and suffer from problems such as reduced heat seal strength.

[0005] Furthermore, films containing silicone resin or silicone oil to improve liquid repellency have also been proposed (see, for example, Patent Documents 3 and 4), but their liquid repellency was not sufficient.

[0006] Furthermore, films made of silylated polyolefins with improved liquid repellency have also been proposed (see, for example, Patent Documents 5, 6, and 7). In addition, films have been proposed in which polyethylene resin is mixed with polypropylene resin to impart easy-peel properties, but their liquid-repellent properties were not sufficient (see, for example, Patent Document 8). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2000-355362 [Patent Document 2] Japanese Patent Publication No. 2001-48229 [Patent Document 3] Japanese Patent Application Publication No. 08-337267 [Patent Document 4] Patent No. 3539723 [Patent Document 5] Patent No. 5990131 [Patent Document 6] Japanese Patent Publication No. 2014-177541 [Patent Document 7] Japanese Patent Publication No. 2015-024548 [Patent Document 8] Patent No. 5394096 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention has been made in consideration of the above technical background, and aims to provide a film and / or packaging bag that is easy to remove from the packaging bag even if the contents are viscous, exhibits sufficient heat sealability, and has excellent easy-peel properties. [Means for solving the problem]

[0009] In view of these circumstances, the inventors conducted diligent studies and found that the above problems can be solved by using a resin composition containing a polypropylene resin and a silylated polyolefin, and by setting the temperature dependence of the heat seal strength in a layer made of this resin composition to a specific range, thus leading to the present invention. In other words, the present invention is a sealant film comprising a seal layer made of a resin composition containing the following (a), (b), and (c), and satisfying the following (1), (2), and (3). (a) Polypropylene resin (b) Polyethylene resin (c) Silylated polyethylene resin (1) The contents of (a), (b), and (c) are 30 to 70% by weight, 10 to 40% by weight, and 3 to 30% by weight, respectively, based on the total resin composition. (2) The silylated polyethylene resin is represented by the following formula. CH3-(CH2) , n-2 , -CH2-S i (CH3)2O-(-S i (CH3)2-O-) d -S i (CH3)2-CH2-(CH2) n-2 -CH3 (In the formula, d is an integer of 1 or more. n is an integer of 100 or more.) (3) The polyethylene resin is at least one polyethylene resin selected from the group consisting of high-pressure low-density polyethylene and linear low-density polyethylene.

[0010] Or, it is a film including a sealant layer composed of a resin composition containing the following (a), (b), and (c), and is a film for a sealant that satisfies the following (4), (5), and (6). (a) Polypropylene resin (b) Polyethylene resin (c) Silylated polyethylene resin (4) The contents of (a), (b), and (c) are 30 to 85% by weight, 10 to 40% by weight, and 3 to 30% by weight, respectively, based on the total resin composition. (5) The silylated polyethylene resin is represented by the following formula. CH3-(CH2) n-2 -CH2-S i (CH3)2O-(-S i (CH3)2-O-) d -S i (CH3)2-CH2-(CH2) n-2 -CH3 (In the formula, d is an integer of 1 or more. n is an integer of 100 or more.) (6) The polyethylene resin is an elastomer consisting of a copolymer of ethylene monomer and α-olefin.

[0011] In these cases, it is preferable that the resin composition contains particles made of inorganic oxides or synthetic resins.

[0012] Furthermore, in these cases, it is preferable that the resin composition contains (d) a fatty acid ester or a fatty acid amide.

[0013] Furthermore, in these cases, it is preferable that the following conditions (7) and (8) be satisfied. (7) The ratio of silicon atoms (Si) to carbon atoms (C) contained in the seal layer (S i The value of / C) is between 0.001 and 0.02. (8) The ratio of silicon atoms (Si) to carbon atoms (C) on the surface of the seal layer (S i The value of / C) is between 0.05 and 0.2.

[0014] Furthermore, in these cases, it is preferable that the following (9) be satisfied. (9) Silicon atoms S contained in the seal layer i and the relative abundance of carbon atoms (S i The silicon atoms S on the surface of the sealing layer relative to / C i and the relative abundance of carbon atoms (S i The ratio of / C) is 2 or greater.

[0015] Furthermore, in these cases, it is preferable that the blocking value of the surface of the sealing layer is 200 mN / 70 mm or less.

[0016] Furthermore, a laminate comprising the sealant film and the base film is also preferred. [Effects of the Invention]

[0017] The present invention provides a packaging bag that allows for easy removal of viscous contents such as pastes and viscous substances, and also provides a sealant film and its laminate that have good heat-sealing properties, as well as excellent slipperiness and blocking resistance. [Brief explanation of the drawing]

[0018] [Figure 1] Average Si concentration and surface Si concentration values ​​of the films described in Comparative Examples 1 and 4, and Examples 2 to 4 and 13. [Figure 2] Schematic diagram of the procedure for evaluating liquid repellency. [Figure 3] EDX mapping measurement photograph of the film surface [Figure 4] TEM observation image of the film cross-section [Figure 5] Photograph of the area around the nozzle of a resin extruder die. [Modes for carrying out the invention]

[0019] (Seal layer) In the present invention, the resin composition constituting the sealing layer must include (a) a polypropylene resin, (b) a polyethylene resin, and (c) a silylated polyolefin resin.

[0020] (Polypropylene resin) The polypropylene resin used in the present invention refers to a homopolymer of propylene monomer, a random copolymer and / or block copolymer of propylene monomer and α-olefin, or a mixture thereof. Examples of α-olefins include ethylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, octen-1, decene-1, and the like.

[0021] The polypropylene resin used is preferably homopolypropylene or a polypropylene random copolymer, and more preferably a polypropylene-α-olefin random copolymer, which is a random copolymer of 85% by weight or more of propylene and 15% by weight or less of α-olefin. When obtaining such a polypropylene random copolymer, ethylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, etc., can be used as α-olefin monomers, but ethylene and butene-1 are particularly preferred from the standpoint of productivity. Furthermore, at least one type of α-olefin is required for copolymerization, and two or more types can be mixed and used as needed.

[0022] The peak melting point temperature of the polypropylene resin is preferably 130°C or higher. The melting point is measured by the method described in the examples below. When the peak melting point temperature of the polypropylene resin is 130°C or higher, the shape of the packaging is less likely to collapse, the film can be transported more smoothly during high-speed packaging processing, and the resulting bags are less prone to wrinkles. In addition, retort processing and semi-retort processing are also possible.

[0023] The lower limit of the density of the polypropylene resin is preferably 880 kg / cm³. 3 More preferably, 885 kg / cm³ 3 It is 880 kg / cm². 3 The above is preferable because it allows for both heat resistance and heat sealability. The upper limit of the density of the polypropylene resin added to the seal layer is preferably 920 kg / cm³. 3 More preferably 900 kg / cm² 3 It is 920 kg / cm². 3 The following is preferable because it allows for both heat resistance and heat sealability.

[0024] The lower limit of the melt flow rate (MFR) of the polypropylene resin is preferably 2.0 g / 10 min, more preferably 2.5 g / 10 min, and even more preferably 2.7 g / 10 min. If it is 2.0 g / 10 min or higher, the polypropylene resin and polyethylene resin are easily finely dispersed without layer separation, and the peel strength between the seal layers after heat sealing does not decrease too much. The upper limit of the melt flow rate of the polypropylene resin is preferably 10.0 g / 10 min, more preferably 8.0 g / 10 min, and even more preferably 7.0 g / 10 min. If it is 10.0 g / 10 min or less, the polypropylene and polyethylene resin do not mix well and are easily finely dispersed, and the peel strength of the seal layers after heat sealing does not decrease too much.

[0025] (Polyethylene resin) The polyethylene resin used in this invention is a copolymer of ethylene monomer and α-olefin. Examples of α-olefins include propylene, butene-1, hexene-1, 4-methylpentene-1, octen-1, decene-1, 3-methylbutene-1, 4-methylpentene-1, and octen-1. The copolymers of ethylene monomers and α-olefins referred to here are generally also called high-pressure low-density polyethylene, linear low-density polyethylene, or polyethylene-based elastomers. Elastomer refers to olefin-based thermoplastic copolymers that exhibit rubber-like elasticity at or near room temperature. The melting points of high-pressure low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and polyethylene-based elastomers are preferably in the range of 50 to 140°C.

[0026] In this invention, the density range of the polyethylene resin raw material used in the formulation is 850 to 970 kg / m³. 3 Preferably, 860-965 kg / m 3 More preferably, 865-960 kg / m 3 A density of 850 kg / m³ is even more preferable. 3 The polyethylene resin described above does not excessively reduce the peel strength between the sealing layers after heat sealing. Its density is 970 kg / m³. 3 The following polyethylene resins similarly do not suffer an excessive decrease in peel strength after heat sealing of the sealing layers. Furthermore, they are easily polymerized.

[0027] The lower limit of the melt flow rate (MFR) of the polyethylene resin is preferably 0.6 g / 10 min, more preferably 1.0 g / 10 min, and even more preferably 1.5 g / 10 min. A MFR of 0.6 g / 10 min or higher makes it easier to obtain fine dispersion of polypropylene and polyethylene resin, and prevents excessive reduction in the peel strength between the seal layers after heat sealing. The upper limit of the melt flow rate of the polyethylene resin is preferably 5.0 g / 10 min, more preferably 4.0 g / 10 min, even more preferably 3.5 g / 10 min, and particularly preferably 3.0 g / 10 min or less. When it is 5.0 g / 10 min or less, fine dispersion of polypropylene and polyethylene resin is easily obtained, and the peel strength of the seal layers after heat sealing is easily reduced.

[0028] By blending and melting the above-mentioned polypropylene resin and polyethylene resin, it is possible to create a fine dispersion state, which can reduce the strength required for peeling after heat sealing between sealing layers or between the sealing layer and the surrounding area of ​​the opening of other container components.

[0029] The strength of peeling after heat sealing between sealing layers or between a sealing layer and the opening area of ​​another container component tends to decrease in the order of ethylene copolymer (polyethylene elastomer), LLDPE, and LDPE. This is presumably because ethylene copolymers have incompatibility with polypropylene resins only in the ethylene portion, LLDPE has side chains which gives it fine dispersibility, and LDPE has long side chains which gives it strong fine dispersibility.

[0030] Specifically, the density is 885 kg / m³. 3 Ethylene-butene copolymer elastomer (Tafmer A1085S, manufactured by Mitsui Chemicals, Inc.) with MFR (230℃, 2.16kg) 2.2g / 10min, density 869kg / m³ 3 An example is an ethylene-propylene copolymer elastomer (Tafmer P0480, manufactured by Mitsui Chemicals, Inc.) with an MFR (230℃, 2.16kg) of 1.8g / 10min.

[0031] (Silylated polyolefin resin) The silylated polyolefin resin used in this invention contains S in its molecule. i It is obtained by reacting a silicon-containing compound having two or more H groups with a vinyl group-containing compound, which is a polymer of at least one olefin selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, and 1-hexene, and which contains a vinyl group at its terminal end.

[0032] S i Examples of silicon-containing compounds having two or more H groups include, for example, methylhydrogenpolysiloxane represented by formula (1), and compounds in which some or all of the methyl groups in formula (1) are substituted with ethyl groups, propyl groups, phenyl groups, trifluoropropyl groups, etc. Formula (1) (CH3)3S i O-(-S i H(CH3)-O-) a -S i (CH3)3 (In formula (1), a is an integer of 2 or more, with an upper limit preferably of 1000, more preferably of 300, and more preferably of 50.)

[0033] S i Other examples of silicon-containing compounds having two or more H groups include, for example, the dimethylsiloxane-methylhydrogensiloxane copolymer represented by formula (2), and compounds in which some or all of the methyl groups in formula (2) are substituted with ethyl groups, propyl groups, phenyl groups, trifluoropropyl groups, etc. Formula (2) (CH3)3S i O-(-S i (CH3)2-O-) b -(-S i H(CH3)-O-) c -S i (CH3)3 (In formula (2), b is an integer of 1 or more, c is an integer of 2 or more, and the upper limit of the sum of b and c is preferably 1000, more preferably 300, and more preferably 50.) Also, in formula (2), -S i (CH3)2-O- units and -S i There are no particular restrictions on the order in which the H(CH3)-O- units are arranged; they can be block-like, disordered, or statistically random.

[0034] S i Further examples of silicon-containing compounds having two or more H groups include, for example, methylhydrogenpolysiloxane represented by formula (3), and compounds in which some or all of the methyl groups in formula (3) are substituted with ethyl groups, propyl groups, phenyl groups, trifluoropropyl groups, etc. Formula (3) HS i (CH3)2O-(-S i (CH3)2-O-) d -S i (CH3)2H (In formula (3), d is an integer of 1 or more, with an upper limit preferably of 1000, more preferably of 300, and more preferably of 50.)

[0035] More specifically, such compounds include, but are not limited to, compounds whose number-average molecular weight corresponds to the structure shown below. HS i (CH3)2O-(-S i (CH3)2-O-)5-S i (CH3)2H HS i (CH3)2O-(-S i (CH3)2-O-)8-S i (CH3)2H HS i (CH3)2O-(-S i (CH3)2-O-) 18 -S i (CH3)2H HS i (CH3)2O-(-S i (CH3)2-O-)80 -S i (CH3)2H HS i (CH3)2O-(-S i (CH3)2-O-) 230 -S i (CH3)2H

[0036] (vinyl group-containing compound) The vinyl group-containing compound used in the present invention is obtained by copolymerizing or polymerizing at least one olefin selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, and 1-hexene.

[0037] The vinyl group-containing compound is preferably an ethylene-α-olefin copolymer in which ethylene-derived structural units are present in a range of 81-100 mol% and α-olefin-derived structural units having 3-20 carbon atoms in a range of 0-19 mol%. More preferably, it is an ethylene-α-olefin copolymer in which ethylene-derived structural units are present in a range of 90-100 mol% and α-olefin-derived structural units having 3-20 carbon atoms in a range of 0-10 mol%. In particular, it is preferable that the ethylene-derived structural units constitute 100 mol%.

[0038] Furthermore, it is preferable that the vinyl group-containing compound has a molecular weight distribution (ratio of weight-average molecular weight to number-average molecular weight, Mw / Mn) measured by gel permeation chromatography (GPC) in the range of 1.1 to 3.0.

[0039] Furthermore, the vinyl group-containing compound preferably has a number-average molecular weight (Mn) in the range of 100 to 500,000, more preferably 500 to 300,000, and even more preferably 1,500 to 100,000.

[0040] Furthermore, the vinyl group-containing compound preferably has a melting point of 70°C to 130°C. The number-average molecular weight of the vinyl group-containing compound in the present invention, as determined by GPC, is 100 to 500,000, more preferably 500 to 300,000, and even more preferably 1,500 to 100,000.

[0041] Furthermore, the vinyl group in the vinyl group-containing compound is preferably located at the end of the main chain, and more preferably the vinyl group is located only at the end of the main chain.

[0042] Furthermore, if a vinyl group-containing compound contains vinyl groups only at the ends of its main chain, 1 The terminal unsaturation rate calculated by 1H-NMR is 80 mol% to 99.5 mol%, more preferably 90 mol% to 99 mol%.

[0043] (Method for producing silylated polyolefin resin) The silylated polyolefin resin used in the present invention is a silylated polyolefin resin or a derivative thereof, or a mixture thereof, obtained by reacting the aforementioned vinyl group-containing compound with a silicon-containing compound in the presence of a transition metal catalyst, according to the method described in Japanese Patent Application Publication No. 2014-223752.

[0044] Specific examples of silylated polyolefin resins include those having structures represented by formulas (4) to (6), but the combinations of silicon-containing compounds and vinyl group-containing compounds are not limited to these examples.

[0045] Formula (4) (CH3)3S i O-(-S i [CH2-(CH2)] n-2 -CH3](CH3)-O-) a -Si(CH3)3 (In formula (4), a is an integer of 2 or more, and its upper limit is preferably 1000, more preferably 300, and more preferably 50.)

[0046] Formula (5) (CH3)3S i O-(-S i (CH3)2-O-) b -(-S i [CH2-(CH2)] n-2 -CH3](CH3)-O-) c -S i (CH3)3 (In formula (5), b is an integer of 1 or more, c is an integer of 2 or more, and the upper limit of the sum of b and c is preferably 1000, more preferably 300, and more preferably 50.)

[0047] Formula (6) CH3-(CH2) n-2 -CH2-S i (CH3)2O-(-S i (CH3)2-O-) d -S i (CH3)2-CH2-(CH2) n-2 -CH3 (In formula (6), d is an integer of 1 or more, with an upper limit preferably of 1000, more preferably of 300, more preferably of 50, and particularly preferably of 25.)

[0048] The silylated polyolefin resin used in the present invention more preferably contains 80% by weight or more of a block copolymer in which both ends of polydimethylsiloxane are polyethylene, as shown in formula (6), and more preferably contains 90% by weight or more. In formula (6), d is preferably an integer of 3 or more, and more preferably 10 or more. In equations (4) to (6), n is preferably an integer of 100 or more, and more preferably 150 or more.

[0049] The silylated polyolefin resin used in the present invention preferably satisfies the following i) and ii) in order to obtain the properties of the film of the present invention and in order to manufacture the film of the present invention, more preferably satisfies the following i) to iii), and even more preferably satisfies the following i) to iv). i) Density of 900-1000 kg / m³ 3 It is within the range of [the specified range]. ii) The melting point is in the range of 100 to 140°C. iii) The number-average molecular weight is in the range of 1,000 to 20,000. iv) The copolymerization rate of the silicone is in the range of 1 to 50% by weight. The chemical formula and molecular weight of the silylated polyolefin resin are identified by the method described in the examples.

[0050] (Resin composition) When polyethylene is LDPE or LLDPE, the content of (a) polypropylene resin, (b) polyethylene resin, and (c) silylated polyolefin resin in the resin composition constituting the seal layer must be 30-70% by weight, 10-40% by weight, and 3-30% by weight, respectively, relative to the total resin composition. (a) The content of polypropylene resin in the resin composition is more preferably 35% by weight or more, even more preferably 40% by weight or more, and particularly preferably 55% by weight or more. (a) When the polypropylene resin content is 30% by weight or more, firmness is maintained. The content of polypropylene resin in the resin composition is more preferably 65% ​​by weight or less, and even more preferably 60% by weight or less. (a) When the polypropylene resin content is 70% by weight or less, easy-peel properties are observed. (b) The content of polyethylene resin in the resin composition is more preferably 12% by weight or more, even more preferably 15% by weight or more, and particularly preferably 20% by weight or more. When the polyethylene resin content is 10% by weight or more, it tends to reduce the peel strength of the seal layers after heat sealing. The content of (b) polyethylene resin in the resin composition is more preferably 35% by weight or less, more preferably 30% by weight or less, and even more preferably 20% by weight or less. When the content of (b) polyethylene resin is about 40% by weight, the heat resistance does not tend to decrease. (c) The content of silylated polyolefin resin in the resin composition is more preferably 5% by weight or more, even more preferably 7% by weight or more, and particularly preferably 12% by weight or more. When the silylated polyolefin resin is contained in an amount of 3% by weight or more, sufficient liquid repellency is obtained, and liquid repellency against edible oils is particularly excellent. The content of (c) silylated polyolefin resin in the resin composition is more preferably 28% by weight or less, even more preferably 25% by weight or less, even more preferably 20% by weight or less, and even more preferably 15% by weight or less. The liquid-repellent effect does not improve much further when the content of (c) silylated polyolefin resin is around 30% by weight. The lower the content of (c) silylated polyolefin resin, the less segregation occurs on the surface of the seal layer.

[0051] When polyethylene resin is used as an elastomer, the content of (a) polypropylene resin, (b) polyethylene resin, and (c) silylated polyolefin resin in the resin composition constituting the seal layer must be 30-85% by weight, 10-40% by weight, and 3-30% by weight, respectively, relative to the total resin composition. (a) The content of polypropylene resin in the resin composition is more preferably 35% by weight or more, even more preferably 40% by weight or more, and particularly preferably 55% by weight or more. (a) When the polypropylene resin content is 30% by weight or more, firmness is maintained. The content of polypropylene resin in the resin composition is more preferably 80% by weight or less, and even more preferably 75% by weight or less. (a) When the polypropylene resin content is 70% by weight or less, the easy-peel properties are maintained. (b) The content of polyethylene resin in the resin composition is more preferably 12% by weight or more, even more preferably 15% by weight or more, and particularly preferably 20% by weight or more. When the polyethylene resin content is 10% by weight or more, it tends to reduce the peel strength of the seal layers after heat sealing. The content of (b) polyethylene resin in the resin composition is more preferably 35% by weight or less, even more preferably 30% by weight or less, and even more preferably 20% by weight or less. When the content of (b) polyethylene resin is about 40% by weight, the heat resistance does not decrease easily. The content of silylated polyolefin resin in the resin composition is more preferably 5% by weight or more, even more preferably 7% by weight or more, and particularly preferably 12% by weight or more. When the silylated polyolefin resin is contained at 3% by weight or more, sufficient liquid repellency is obtained, and liquid repellency against edible oils is particularly excellent. The content of (c) silylated polyolefin resin in the resin composition is more preferably 25% by weight or less, even more preferably 20% by weight or less, and even more preferably 15% by weight or less. The liquid-repellent effect does not improve much further when the content of (c) silylated polyolefin resin is around 30% by weight. The lower the content of (c) silylated polyolefin resin, the less segregation occurs on the surface of the seal layer. The content of a) polypropylene resin, (b) polyethylene resin, and (c) silylated polyolefin is determined by the method described in the examples.

[0052] (particle) The resin composition constituting the seal layer preferably contains particles, and the particles are preferably made of inorganic oxides or synthetic resins. The inclusion of particles makes it easier to set the arithmetic mean roughness Ra of the surface of the seal layer to 0.03 μm or more and 0.3 μm or less. As a result, the coefficient of dynamic friction between the surfaces of the seal layers of the film or between the seal layer and the surface opposite it, and the blocking strength of the sliding between the surfaces of the seal layers of the film are easily reduced significantly. One possible reason for this is that (c) the silylated polyolefin resin is unevenly distributed on the surface of the sealing layer, and by imparting specific irregularities to the film surface, which has reduced crystallinity and hardness, the effects of this reduction are minimized, and the coefficient of dynamic friction and blocking strength are greatly reduced. The weight-average particle diameter of the particles made of inorganic oxides or synthetic resins is preferably 2 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more. The weight-average particle size is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The weight-average particle size is measured using the method described in the examples. Examples of particles made from synthetic resins include crosslinked acrylic particles, polymethacrylic acid particles, silicone resin particles, and polyethylene particles. Examples of particles made from inorganic oxides include particles made from silicon dioxide, particles made from calcium carbonate, zeolite, and particles made from diatomaceous earth. Among silicon dioxide particles, silica particles or synthetic silica particles are preferred, but diatomaceous earth may also be used in combination. The content of particles made of inorganic oxides or synthetic resins in the resin composition is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, and even more preferably 0.4% by weight or more. Furthermore, it is preferably 3.0% by weight or less, more preferably 2.5% by weight or less, and even more preferably 2.0% by weight or less. When the content of particles made of inorganic oxides or synthetic resins is 3.0% by weight or less, the surface protrusions do not become too large, and the liquid repellency does not decrease easily.

[0053] (Organic lubricant) The resin composition constituting the seal layer preferably contains an organic lubricant, and a fatty acid amide is preferred as the organic lubricant. The inclusion of an organic lubricant, in combination with the arithmetic mean roughness Ra of the seal layer surface being 0.03 μm or more and 0.3 μm or less, tends to improve the blocking resistance and slipperiness of the seal layer. Examples of fatty acid amides include oleamide, erucamide, behenamide, ethylenebisoleamide, and hexamethylenebisoleamide. While these can be used individually, using two or more in combination is preferable because it can maintain lubricity and anti-blocking effects even in harsh environments. On the other hand, fatty acid esters are widely known as emulsifiers and are also known to impart hydrophilicity to the film surface as anti-fogging agents. However, in the present invention, they are undesirable because they not only reduce water repellency but also impair oil repellency. Furthermore, many fatty acid esters have low melting points, raising concerns about stickiness due to bleed-out and poor appearance. Considering these points, fatty acid amides are preferred. It is preferable to add an organic lubricant with a melting point of 25°C or higher. The content of (d) fatty acid amides and fatty acid esters in the resin composition is preferably 0.01 to 0.5% by weight, more preferably 0.05 to 0.4% by weight, and particularly preferably 0.1 to 0.3% by weight. If the fatty acid amide content is 0.5% by weight or less, the seal strength is less likely to decrease.

[0054] (others) Within the limits that do not impair the performance of the sealant film of the present invention, the resin composition may optionally contain additives such as antioxidants, heat stabilizers, weather stabilizers, and crystal nucleating agents, as well as ethylene-vinyl acetate copolymers and ethylene-acrylic acid ester copolymers.

[0055] (Film forming method) The method for producing the sealant film of the present invention preferably involves, for example, a step of melt-kneading a polypropylene resin composition containing a polyethylene resin, a step of melt-extruding the melt-kneaded resin composition to form a molten resin composition sheet, and a step of cooling and solidifying the molten resin composition sheet. The sealant film of the present invention may be a single layer, but laminated is more preferable. In the case of laminated film, a layer containing a polyethylene resin and a silylated polyolefin, with an arithmetic mean roughness of at least one surface layer of 0.03 μm or more and 0.3 μm or less, may be provided with another layer made of a thermoplastic resin composition, preferably a polyolefin resin composition. For single-layer films, the film thickness is preferably 3 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, and particularly preferably 20 μm or more. Furthermore, a thickness of 200 μm or less is preferred, more preferably 150 μm or less, and particularly preferably 100 μm or less. Below 3 μm, the effect of silica particles decreases, making it difficult to achieve slip resistance and locking resistance. The details are explained below. The longitudinal direction refers to the direction in which the unstretched sheet is run, and the width direction refers to the direction perpendicular to that.

[0056] (raw material mixing process) When mixing silylated polyolefin resin with polyethylene resin, or with particles such as silica particles and polypropylene resin, any method that ensures uniform mixing is acceptable. If a masterbatch is used, this may involve mixing using a ribbon blender, Henschel mixer, tumbler mixer, etc.

[0057] (Melting and mixing process) First, the film raw materials, such as polypropylene resin, are dried or hot-air dried until their moisture content is less than 1000 ppm. Next, each raw material is weighed, mixed, and supplied to an extruder for melt-kneading. The lower limit of the melting and mixing temperature of the polyethylene resin composition is preferably 200°C, more preferably 210°C, and even more preferably 220°C. Below this temperature, dispensing may become unstable. The upper limit of the resin melting temperature is preferably 260°C. Above this temperature, the resin decomposes, and as a result of recombination, the amount of crosslinked organic matter, so-called gel and other foreign matter increases. When the polyethylene resin composition contains the above-mentioned antioxidant, melt extrusion at higher temperatures becomes possible, but it is preferable to keep it below 270°C.

[0058] (Filtration) In the melt-mixing process, high-precision filtration can be performed to remove foreign matter contained in the molten polyethylene resin composition. The filter material used for high-precision filtration of the molten resin is not particularly limited, but a stainless steel sintered body filter material is preferable because it has excellent performance in removing not only foreign matter such as gel, but also aggregates mainly composed of Al, Si, Ti, Sb, Cu, and Ge derived from additives such as catalysts. Furthermore, the filtration accuracy is preferably 200 μm or less.

[0059] (Filter boost) It is preferable to have a small amount of pressure increase during the melt-kneading of the polyethylene resin composition.

[0060] (Melting extrusion process) Next, the molten polypropylene resin composition sheet is extruded, for example, through a T-type die, cast onto a cooling roll, and cooled and solidified to obtain an unstretched sheet. A preferred method for this is casting onto a cooling roll. Since the silylated polyolefin used in this invention is a copolymer with polyethylene, bleed-out is not observed even after melt kneading and extrusion processes, and the accumulation of foreign matter and deposits that can occur when silicone resin is added is extremely unlikely to occur. Methods include melt-extruding a sheet of melt-kneaded polypropylene resin composition and then forming a film using the T-die method or the inflation method, but the T-die method is particularly preferable because it allows for a higher melting temperature of the resin.

[0061] (Lip stain (bleed-out)) When melt-extruding silylated polyolefin, silica particles, and polypropylene resin from a T-type die, it is preferable to minimize contamination of the lip opening of the T-type die. The method for measuring lip contamination was described in the examples.

[0062] (Cooling solidification process) For example, it is preferable to cast a molten sheet of a polyethylene resin composition, extruded from a T-type die, onto a cooling roll and cool it. The lower limit of the cooling roll temperature is preferably 10°C. Below this temperature, the crystallization inhibition effect may saturate, and problems such as condensation may occur, which is undesirable. The upper limit of the cooling roll temperature is preferably 70°C or lower. Above this temperature, crystallization progresses, resulting in poor transparency, which is undesirable. Furthermore, when the cooling roll temperature is within the above range, it is preferable to lower the humidity of the environment near the cooling roll to prevent condensation. In casting, the surface temperature of the cooling roll rises because it comes into contact with high-temperature resin. Normally, the cooling roll is cooled by circulating cooling water through pipes inside, but it is necessary to minimize the temperature difference in the width direction of the cooling roll surface by ensuring a sufficient amount of cooling water, devising a suitable pipe layout, and performing maintenance to prevent sludge buildup on the pipes. In this case, the thickness of the unstretched sheet is preferably in the range of 3 to 200 μm.

[0063] (Multi-layer configuration) The sealant film of the present invention preferably has a multilayer structure. In the case of a multilayer structure, in addition to having at least one layer on one side that contains a polyolefin resin and a silylated polyolefin and has an arithmetic mean roughness of 0.03 μm or more and 0.3 μm or less on the surface layer, one or more other layers made of a thermoplastic resin composition, preferably a polyolefin resin composition, may be provided. By creating a multilayer structure and including silylated polyolefin resin only in the surface layer, the amount of silylated polyolefin resin used can be reduced, and its precipitation can also be minimized. Furthermore, other properties of the film can be improved, or new functions can be added. As a specific method for creating such a multi-layer structure, general multi-layer devices (such as multi-layer feed blocks, static mixers, and multi-layer multi-manifolds) can be used. For example, a method can be used in which thermoplastic resins extruded from two or more extruders through different flow paths are laminated in multiple layers using a feed block, static mixer, multi-manifold die, etc. Alternatively, it is possible to use only one extruder and introduce the above-mentioned multilayering device into the melt line from the extruder to the T-type die.

[0064] In the case of a two-layer structure, it is preferable that at least one of the layers contains a polyolefin resin and a silylated polyolefin resin, and that the arithmetic mean roughness of the surface layer is 0.03 μm or more and 0.3 μm or less, and that this layer is designated as the seal layer (layer A), while the other layer, which is made of a thermoplastic resin composition, preferably a polyolefin resin composition, is designated as the laminate layer (layer C).

[0065] In the case of a three-layer structure, it is preferable to have a seal layer (layer A) containing a polyolefin resin and a silylated polyolefin resin, with an arithmetic mean roughness of the surface layer of the surface layer being 0.03 μm or more and 0.3 μm or less, and to have the other layers made of a thermoplastic resin composition, preferably a polyolefin resin composition, as the intermediate layer (layer B) and the laminate layer (layer C), respectively, in this order. The outermost layers are layers A and C, respectively.

[0066] For the intermediate layer (layer B) and the laminate layer (layer C), polyethylene resin and polypropylene resin are preferable.

[0067] (Polyethylene resin) The polyethylene resin used in the intermediate layer (layer B) and the laminate layer (layer C) is one of the following: a homopolymer of ethylene monomers, a copolymer of ethylene monomers and α-olefins, a copolymer of ethylene monomers and other monomers, or a mixture thereof. Examples of α-olefins include propylene, butene-1, hexene-1, 4-methylpentene-1, octen-1, decene-1, 3-methylbutene-1, 4-methylpentene-1, and octen-1. Examples of other monomers include monomers such as vinyl acetate, (meth)acrylic acid, (meth)acrylic acid esters, and the like. The polyethylene resin can be any of a crystalline, or a low-crystalline to non-crystalline random or block copolymer, or a mixture thereof. Copolymers of ethylene monomers and α-olefins are sometimes generally referred to as high-pressure low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene. When using these polyethylene resins, they have excellent heat-sealing strength, hot tack property, sealing property for contaminants, and impact resistance. However, it is better that the copolymer of ethylene monomer and other monomers is in a small amount or not contained. At this time, the polyethylene resins used for the intermediate layer (B layer) and the laminate layer (C layer) may be the same or different.

[0068] In this case, it is preferable that the average density of the polyethylene resins in each layer of the film is such that the sealant layer (A layer) ≤ the intermediate layer (B layer) ≤ the laminate layer (C layer). Since the organic lubricant incorporated is less likely to move to the layer with a higher density, it is effective for maintaining the slipperiness of the sealant layer after lamination. At this time, the lower limit of the density of the intermediate layer (B layer) is preferably 880 kg / m 3 and more preferably 890 kg / m 3 and even more preferably 900 kg / m 3 is. If it is less than the above, it may be weak and difficult to process. The upper limit of the density of the intermediate layer (B layer) is preferably 940 kg / m 3 and more preferably 930 kg / m 3 and even more preferably 920 kg / m 3 is.

[0069] (Polypropylene resin) The polypropylene resins used in the intermediate layer (layer B) and the laminate layer (layer C) are homopolymers of propylene monomers, random copolymers and / or block copolymers of propylene monomers and α-olefins, and mixtures thereof. Examples of α-olefins include ethylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, octen-1, decene-1, and the like.

[0070] The above-mentioned organic lubricant may be used in the intermediate layer (layer B) of the film of the present invention, and the lower limit of the organic lubricant is preferably 200 ppm, more preferably 400 ppm. If it is less than the above, the lubricity may deteriorate. The upper limit of the erucic acid amide concentration in the intermediate layer is preferably 2000 ppm, and more preferably 1500 ppm. Exceeding this limit may cause excessive slippage and lead to winding misalignment.

[0071] The intermediate layer (layer B) of the film of the present invention may contain 10 to 30% by mass of the recovered resin. In the present invention, it is preferable to perform an activated radiation treatment, such as corona treatment, on the laminate layer (C layer) surface of the polyethylene-based sealant film as exemplified above. This treatment improves the laminate strength.

[0072] (Film characteristics) The properties of the sealant film of the present invention will be described in detail. (Ratio of silicon atoms (Si) to carbon atoms (C) in the seal layer (Si / C) (average Si concentration)) It is preferable that the ratio of silicon atoms (Si) to carbon atoms (C) in the sealing layer of the sealant film of the present invention (Si / C) is 0.001 or higher. A ratio of 0.001 or higher improves the liquid repellency to viscous contents such as cooking oil, tonkatsu sauce, and soy sauce. A ratio of 0.005 or higher is more preferable, 0.007 or higher is even preferable, and 0.01 or higher is particularly preferable. It is preferable that the abundance ratio (Si / C) of silicon atoms Si and carbon atoms C in the seal layer of the film for a sealant of the present invention is 0.02 or less. When it is 0.02 or less, the peel strength is less likely to decrease. More preferably, it is 0.018 or less, and even more preferably, it is 0.016 or less. The measurement method is carried out by the method described in the examples.

[0073] (The abundance ratio of silicon atoms S i and carbon atoms C (S i / C) (surface S i concentration)) It is preferable that the abundance ratio (S i / C) of silicon atoms Si and carbon atoms C on the surface of the seal layer of the film for a sealant of the present invention is 0.05 or more. When it is 0.05 or more, the liquid repellency against viscous contents such as edible oil, tonkatsu sauce, and soy sauce is improved, and particularly the effect of improving the liquid repellency against edible oil is very large. More preferably, it is 0.07 or more, even more preferably, it is 0.1 or more, preferably 0.13 or more, and particularly preferably 0.15 or more. The abundance ratio of silicon atoms S i and carbon atoms C (S i / C) on the surface of the seal layer of the film for a sealant of the present invention is preferably 0.3 or less. When it is 0.3 or less, the heat seal strength is likely to decrease. More preferably, it is 0.2 or less. The measurement method is carried out by the method described in the examples.

[0074] (Ratio of surface Si concentration to average Si concentration) The ratio of the abundance ratio (S i / C) of silicon atoms S and carbon atoms C contained in the seal layer of the film for a sealant of the present invention to the abundance ratio (S i / C) of silicon atoms S and carbon atoms C on the surface of the seal layer is preferably 2 or more, more preferably 3 or more, even more preferably 5 or more, still more preferably 6 or more, particularly preferably 8 or more, and most preferably 10 or more. ​​​The measurement method shall be as described in the examples. (Arithmetic mean roughness Ra) It is preferable that the arithmetic mean roughness Ra of the surface of the sealing layer of the sealant film of the present invention is 0.03 μm or more. A roughness of 0.03 μm or more reduces the coefficient of dynamic friction between the layers themselves or between the layers and the film surface on the opposite side of the layers, and makes it easier to lower the coefficient of dynamic friction between the surfaces of the sealing layers of the film or between the sealing layers and the surface on the opposite side of the layers. It also makes it easier to lower the blocking strength of the sliding between the surfaces of the sealing layers of the film. As a result, the handling of the film is improved. It is more preferable that the arithmetic mean roughness of the surface of the sealing layer is 0.05 μm or more, and even more preferable that it is 0.07 μm or more. It is preferable that the arithmetic mean roughness Ra of the surface of the sealing layer of the sealant film of the present invention is 0.3 μm or less. When it is 0.3 μm or less, the coefficient of dynamic friction between the layers or between the layers and the film surface on the opposite side of the layer is not too small, the film is less likely to slip during winding, and the handling of the film is improved. It is more preferable that it is 0.25 or less. The measurement method shall be as described in the examples.

[0075] (Maximum protrusion height Rz) It is preferable that the maximum protrusion height Rz on the surface of the sealing layer of the sealant film of the present invention is 1 μm or more. When it is 1 μm or more, the contact area between the layers or between the layer and the film surface on the opposite side of the layer is reduced, the blocking prevention effect is greatly improved, and the handling of the film is improved. It is more preferable that the maximum protrusion height Rz on the surface of the sealing layer is 1 μm or more, and even more preferable that it is 3 μm or more. It is preferable that the maximum protrusion height Rz on the surface of the sealing layer of the sealant film of the present invention is 30 μm or less. When it is 30 μm or less, the volume of the gap between the layers or between the layer and the film surface on the opposite side of the layer is not too large, the film is less likely to shift during winding, and the handling of the film is improved. It is more preferable that it is 25 μm or less. The measurement method shall be as described in the examples.

[0076] (Young's modulus / longitudinal direction) The lower limit of the Young's modulus (longitudinal direction) of the sealant film of the present invention is preferably 100 MPa, more preferably 150 MPa, even more preferably 200 MPa, and particularly preferably 250 MPa. A Young's modulus of 100 MPa or higher is not too weak and is easy to process. The upper limit of the Young's modulus (longitudinal direction) of the sealant film of the present invention is preferably 600 MPa, more preferably 500 MPa, and even more preferably 400 MPa.

[0077] (Young's modulus / width direction) The lower limit of the Young's modulus (width direction) of the sealant film of the present invention is preferably 100 MPa, more preferably 150 MPa, even more preferably 200 MPa, and particularly preferably 250 MPa. A Young's modulus of 100 MPa or higher is not too weak and is easy to process. The upper limit of the Young's modulus (width direction) of the sealant film of the present invention is preferably 600 MPa, more preferably 500 MPa, and even more preferably 400 MPa.

[0078] (Hayes) The upper limit of the haze of the sealant film of the present invention is preferably 15%, more preferably 10%, and even more preferably 6%. A haze level of 15% or less makes it easier to see the contents. The lower limit of the haze of the sealant film of the present invention is preferably 0%, but 2% is also practically satisfactory. The measurement method shall be as described in the examples.

[0079] (liquid repellency) The amount of viscous contents such as edible oil, tonkatsu sauce, and soy sauce remaining attached to the sealant film of the present invention, which is an indicator for evaluating the liquid repellency of the sealant film, should be 0.08 mg / 28 cm for at least two of these substances. 2 The following is preferable, with 0.8 mg / 28 cm for each of the three types. 2 The following is more preferable: The measurement method shall be as described in the examples.

[0080] (State of presence of silylated polyolefin resin) In the sealant film of the present invention, it is preferable that the silylated polyolefin resin is segregated on the surface of the seal layer. However, it is preferable that the silylated polyolefin resin is not deposited on the surface of the seal layer in a separated state. Furthermore, in this case, it is preferable that the silylated polyolefin resin is finely dispersed in the sealing layer of the sealant film of the present invention, exhibiting a microphase separation structure. The state of presence of silylated polyolefin resin or silicone resin on the surface of the seal layer can be observed using a scanning electron microscope, and qualitative analysis of Si and C elements can also be performed using energy-dispersive X-rays. Furthermore, the cross-section of the sealing layer can be observed using a transmission electron microscope. The measurement will be performed using the method described in the examples.

[0081] (Coefficient of kinetic friction) The upper limit of the dynamic friction coefficient between the sealing layers of the sealant film of the present invention is preferably 1.5, more preferably 1.0, even more preferably 0.7, even more preferably 0.5, particularly preferably 0.4, and most preferably 0.3. When the dynamic friction coefficient between the sealing layers is 1.5 or less, the opening of the bag after forming is good, and processing losses are easily reduced. The lower limit of the dynamic friction coefficient between the sealing layers of the sealant film of the present invention is preferably 0.05, more preferably 0.08, and even more preferably 0.1. When it is 0.05 or more, heat sealing during bag forming is easy, and processing losses are easily reduced. The upper limit of the coefficient of dynamic friction between the sealing layer and the opposite surface of the film in the sealant film of the present invention is preferably 2.0, more preferably 1.5, even more preferably 1.2, even more preferably 1.0, particularly preferably 0.7, and most preferably 0.5. When the coefficient of dynamic friction between the sealing layer and the opposite surface of the film is 2.0 or less, wrinkles are less likely to occur in the film during winding, and processing losses are easily reduced. The lower limit of the coefficient of dynamic friction between the sealing layer and the opposite surface of the film in the sealant film of the present invention is preferably 0.05, more preferably 0.08, and more preferably 0.1. If it is 0.05 or higher, the film will not slip too much during winding and will not be easily misaligned during winding. The measurement method shall be as described in the examples.

[0082] (Coefficient of static friction) The upper limit of the static friction coefficient between the sealing layers of the sealant film of the present invention is preferably 1.5, more preferably 1.0, even more preferably 0.7, even more preferably 0.5, particularly preferably 0.4, and most preferably 0.3. When the dynamic friction coefficient between the sealing layers is 1.5 or less, the bag opening after forming is good, and losses during processing are easily reduced. The lower limit of the static friction coefficient between the sealing layers of the sealant film of the present invention is preferably 0.05, more preferably 0.08, and more preferably 0.1. A value of 0.05 or higher facilitates heat sealing during bag making and reduces losses during processing. The measurement method shall be as described in the examples.

[0083] (Blocking value) The upper limit of the surface-to-surface sliding blocking value of the sealant film of the present invention is preferably 100 mN / 70 mm, more preferably 90 mN / 70 mm, even more preferably 80 mN / 70 mm, particularly preferably 70 mN / 70 mm, and most preferably 60 mN / 20 mm. When the surface-to-surface sliding blocking strength of the sealant film is 100 mN / 70 mm or less, the film can be unwound smoothly from the film roll for processing. The lower limit of the surface-to-surface sliding blocking strength of the sealant film of the present invention is preferably 0 mN / 70 mm, but 15 mN / 70 mm is also practically satisfactory. The measurement method shall be as described in the examples.

[0084] (Easy peel strength at 150℃) The 150°C easy-peel strength of the sealant film of the present invention is preferably 25 mN / 15 mm or less, preferably 20 mN / 15 mm or less, and more preferably 15 mN / 10 mm or less. The measurement method shall be as described in the examples.

[0085] (Easy peel strength at 190℃) The 190°C easy-peel strength of the sealant film of the present invention is preferably 30 mN / 15 mm or less, preferably 25 mN / 15 mm or less, and more preferably 20 mN / 15 mm or less. The measurement method shall be as described in the examples.

[0086] (200℃ Easy Peel Strength) The 200°C easy-peel strength of the sealant film of the present invention is preferably 35 mN / 15 mm or less, preferably 30 mN / 15 mm or less, and more preferably 25 mN / 20 mm or less. The measurement method shall be as described in the examples.

[0087] (150°C peel strength) The 150°C peel strength of the sealant film of the present invention is preferably 0.5 N / 15 mm or more, preferably 0.7 N / 15 mm or more, and more preferably 0.9 N / 15 mm or more. The measurement method shall be as described in the examples.

[0088] (190°C peel strength) The 190°C peel strength of the sealant film of the present invention is preferably 1 N / 15 mm or more, preferably 1.5 N / 15 mm or more, and more preferably 1.8 N / 15 mm or more. The measurement method shall be as described in the examples.

[0089] (200°C peel strength) The 200°C peel strength of the sealant film of the present invention is preferably 1 N / 15 mm or more, preferably 1.5 N / 15 mm or more, and more preferably 1.8 N / 15 mm or more. The measurement method shall be as described in the examples.

[0090] (Laminated structure) The present invention provides a laminate in which at least one other base film is further laminated onto the sealant film, and is generally used as a packaging film or packaging sheet. The base film is not particularly limited, but may be polyolefin films such as polyethylene or polypropylene, styrene resin films, polyester films such as polyethylene terephthalate or polybutylene terephthalate, polyamide films such as nylon 6 or nylon 6,6, or stretched films thereof, laminated films of polyolefin films and gas barrier resin films such as polyamide films or ethylene-vinyl alcohol copolymer films, metal foils such as aluminum, or vapor-deposited films or paper with aluminum or silica vapor-deposited on them, as appropriate depending on the intended use of the laminate. This base film can be used not only as a single type, but also in combination of two or more types for lamination.

[0091] The base film adjacent to the sealant layer preferably does not contain the silylated polyolefin. Furthermore, the base film adjacent to the sealant layer is preferably a polyolefin film.

[0092] Methods for laminating the sealant film onto the above-mentioned base film include dry lamination of the base film (Y) and the sealant film, and extrusion lamination, in which only the sealant layer resin is extruded onto the base film. Of these, dry lamination is preferred from the viewpoint of productivity.

[0093] To achieve stronger adhesion between the sealant film of the present invention and other substrate films, the structure can be configured as sealant film / adhesive layer / other substrate film. As the adhesive layer, anchor coating agents such as urethane-based or isocyanate-based adhesives can be used, or modified polyolefins such as unsaturated carboxylic acid grafted polyolefins can be used as adhesive resins to firmly bond adjacent layers.

[0094] There are no particular restrictions on the thickness of the laminate, but when the laminate is used as a film for lids or the like, it is preferably 10 to 200 μm thick, and when it is used as a sheet for cups or trays, it is preferably 200 to 1000 μm thick.

[0095] (packaging) A container can be manufactured by placing the sealant films of the aforementioned laminate facing each other, or by placing the sealant film layer of the laminate facing another base film, and then heat-sealing at least a portion of its periphery from the outer surface side to achieve the desired container shape. Alternatively, a sealed bag-shaped container can be manufactured by heat-sealing the entire periphery. When this bag-shaped container molding process is combined with a content filling process, that is, by heat-sealing the bottom and sides of the bag-shaped container, filling it with content, and then heat-sealing the top, a package can be manufactured. Therefore, this laminate can be used in automatic packaging equipment for solids such as snack foods, powders, or liquid materials.

[0096] Furthermore, a container containing contents can also be obtained by filling a container formed into a cup shape by vacuum forming or pressure forming, a container obtained by injection molding or blow molding, or a container formed from a paper substrate with contents, then covering it with the laminate of the present invention as a lid material and heat sealing it. [Examples]

[0097] The embodiments of the present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The measured values ​​for each item in the detailed description of the present invention, as well as in the examples and comparative examples, were measured using the following method.

[0098] (Characteristics of raw materials) The density, melt flow rate (MFR), and melting point of polyolefin resins and silylated polyolefins used in the preparation of sealant films, as well as the weight-average particle size and content ratio of particles made of inorganic oxides or synthetic resins, were measured by the following methods. These values ​​can also be obtained by measuring the entire layer if the sealant film is a single layer, or by examining the boundary of the relevant layer if it is a multilayer film using an electron microscope, scraping off only the relevant layer, filtering the solution in which only the target raw material is dissolved in a solvent, and then measuring the residue after removing the solvent. When scraping off only the relevant layer from a multilayer film, this can be done relatively easily by laminating the sealant film onto a polyethylene terephthalate (PET) film and then scraping it off with a razor or similar tool.

[0099] (Density:kg / cm 3 ) The density was measured using the density gradient pipe method in accordance with JIS-K7112.

[0100] (Melt Flow Rate (MFR): g / 10 min) In accordance with JIS-K7210, polyethylene resins were measured at 190°C and polypropylene resins at 230°C.

[0101] (Melting point: °C) A differential scanning calorimeter (DSC) manufactured by SII was used, with a sample volume of 10 mg and a heating rate of 10°C / min. The detected endothermic fusion peak temperature was defined as the melting point.

[0102] (Content of particles made of inorganic oxides or synthetic resins in the film: weight %) The content of particles consisting of inorganic oxides or synthetic resins in the film was calculated from the amount added to the raw resin composition before processing. Furthermore, even after film formation, it is possible to separate and measure silica particles by dissolving the film at a temperature at which it completely dissolves using decane as a solvent, and then filtering the residue through a filter with a filtration accuracy of 2 μm. (Weight-average particle size of particles made of inorganic oxides or synthetic resins: μm) Particles made of inorganic oxides or synthetic resins can be calculated, for example, as the particle size at which the smallest particle size accounts for 50% of the cumulative mass in the particle size distribution curve measured using the Nikkiso Co., Ltd. laser diffraction / scattering particle size distribution analyzer "MT3200II".

[0103] The ease with which compounds precipitate from the resin composition constituting the sealing layer of the obtained sealant film was measured by the following method. (Ease of compound precipitation from the resin composition constituting the sealing layer) For the resin composition used in the sealing layer of Comparative Example 1, molten resin was extruded at 230°C from numerous 4 mm diameter nozzles provided in the width direction of the extruder die. The degree of compound deposition (contamination) around the nozzles was visually observed one hour after the start of extrusion, and this was used as the standard (○) to classify the results as ○ or × below. ○: No compound deposits were observed around the nozzle. ×: Clear deposition of compounds around the nozzle is visible.

[0104] (Properties of sealant film) The properties of the obtained sealant films were measured using the following methods.

[0105] (Ratio of silicon atoms (Si) and carbon atoms (C) on the surface of the sealing layer) The surface of the sealant film's sealing layer was wiped with ethanol before measurement. The sealing layer surface was excited using an X-ray electron spectroscopy (ESCA) analyzer (Thermo Fisher Scientific K-Alpha) with the following settings: excitation X-ray: monochromatized ALKα, X-ray output: 12kV, 6mA, photoemission angle: 90°, spot size: 400μmφ, pass energy: 50eV (narrow scan), step: 0.1eV (narrow scan). The surface composition ratio of the elements detected was then calculated. Furthermore, the obtained elemental surface composition ratios are for a depth region of several nm to approximately 10 nm from the film surface.

[0106] (The ratio of silicon atoms (Si) and carbon atoms (C) contained in the seal layer (S i / C)(Average Si concentration)) 1) After roughly understanding the layer structure by observing the cross-section beforehand, only the resin composition constituting the sealing layer was scraped off using a feather blade. The scraped material was completely dissolved at 135°C in a mixed solvent of o-dichlorobenzene / deuterated benzene = 80 / 20 by volume ratio. The sample concentration was approximately 25-30 mg / 0.7 mL. One-dimensional S i - For NMR measurements, approximately 1 wt% acetylacetone chromium(III) was added to the measurement solution. The following measurements were performed on this sample to identify the chemical formula, molecular weight, and content of the silylated polyolefin resin contained in the resin composition constituting the seal layer. 2) First, the one-dimensional NMR 1 H-NMR spectrum, 13 C-NMR spectrum, 13 C-DEPT spectrum, and 29 S i Using NMR spectra, and referring to Aldrich standard spectra and standard samples, we investigated how the H, C, and Si elements are bonded together and identified the approximate structure of the compound. The measurement conditions are shown below. Equipment: Fourier transform nuclear magnetic resonance spectrometer (Bruker Japan Co., Ltd. AVANCE NEO 600 model) Resonance frequency::1 H-NMR: 600.13MHz, 13 C-NMR: 150.92MHz, 29 S i -NMR: 119.22MHz Measurement temperature:: 1 H-NMR: 110 or 115°C, 13 C-NMR: 110 or 115°C, 13 C-DEPT: 110 or 115℃, 29 Si-NMR: 110℃ Pulse repetition time: 1 H-NMR: 3.75 seconds, 13 C-NMR: 2.8~2.9 seconds, 13 C-DEPT: 3.5 seconds, 29 S i -NMR:7.0 seconds Detection pulse angle: 1 H-NMR: 30°, 13 C-NMR: 30°, 29 S i -NMR:90° 1 H-DeCouple Methods: 13 C-NMR: Full decoupled, 29 S i -NMR: Inverse gate decoupler (FID acquisition time 0.7 seconds) Total number of times: :1 H-NMR: 16 times, 13 C-NMR: about 300 to 1200 times, 13 C-DEPT: Approximately 100-1100 times, 29 S i -NMR: Approximately 4000 times 3) Furthermore, two-dimensional NMR, COSY, TOCSY, 13 C-HSQC, HMBC, 29 S i -Using HMBC, adjacent 1 The correlation peaks between H, and the next one, and the one after that, are all connected. 1 Correlation peaks between H, directly coupled 1 H, 13 C correlation peak, heteronuclei separated by 2- or 3-bonds ( 1 H, 13C) Correlation peaks, heteronuclei separated by two or three bonds ( 1 H, 29 By examining the correlation peaks of Si, we were able to more precisely identify the structural connections that were revealed by one-dimensional NMR. 4) The ratio of silicon atoms per carbon atom in the resin composition constituting the sealing layer of the sealant film (S i The average Si concentration ( / C) can be determined from the molecular formula and molecular weight of the silylated polyolefin resin contained in the resin composition, and its content ratio in the resin composition constituting the seal layer. Below is a specific example of the calculation method when the resin composition constituting the seal layer is a polymer consisting only of ethylene-derived structural units containing vinyl groups at the ends of the main chain, a silylated polyolefin resin using dimethylsiloxane as a raw material compound, and a polyethylene resin. By calculating the dimethylsiloxane concentration in the silylated polyolefin resin from its molecular formula, and assuming this resin concentration is 26% by weight, the average polydimethylsiloxane concentration in a composition made by adding 10 parts by weight of this silylated polyolefin to 90 parts by weight of polypropylene resin will be 2.6% by weight. The molecular formula for one unit of dimethylsiloxane is C2H6S. i O (unit molecular weight 74.15), the molecular formula per unit of polyolefin in silylated polyolefin resin is C2H4 (unit molecular weight 28.05), and the molecular formula per unit of propylene in polypropylene resin is C3H6 (unit molecular weight 42.08). The amount of dimethylsiloxane per 1 kg of resin composition is (1000 × 2.6 / 100) / 74.15 = 0.35 mol, the amount of polyolefin in the silylated polyolefin resin is (1000 × (10 - 2.6) / 100) / 28.05 = 2.6 mol, and the amount of polypropylene resin is (1000 × 90 / 100) / 42.08 = 21.4 mol. Therefore, per 1 kg of resin composition, S i The amount of silicon is 0.35 mol, and the amount of carbon is 0.35 × 2 + 2.6 × 2 + 21.4 × 2 = 48.7 mol, which is the silicon atom abundance per carbon atom in the resin composition (S i / C) is calculated as 0.35 / 48.7 = 0.007.

[0107] (Arithmetic mean roughness Ra:μm) The arithmetic mean roughness Ra of an arbitrary 1 mm x 0.2 mm area on the surface of the sealing layer of a 3 cm x 3 cm sealant film was determined in accordance with JIS B0601-2001 using a contact surface roughness tester (Kosaka Laboratory, model ET4000A). Measurements were taken at three locations, and the average value was taken as the arithmetic mean roughness Ra.

[0108] (Maximum protrusion height Rz:μm) The maximum protrusion height Rz was determined at an arbitrary 1mm x 0.2mm portion of the surface of the sealing layer of a 3cm x 3cm square sealant film using a contact surface roughness tester (Kosaka Laboratory, model ET4000A) in accordance with JIS B0601-2001. Measurements were taken at three locations, and the average value was defined as the maximum protrusion height Rz.

[0109] (Young's modulus, tensile strength, tensile elongation) The Young's modulus of the obtained sealant film was measured at 23°C in accordance with JIS K7127, in both the longitudinal and widthwise directions. The sample was cut from the film to a size of 15 mm x 200 mm, and the chuck width was 100 mm. It was then set on a tensile testing machine (Instron 5965, a dual-column benchtop testing machine manufactured by Instron Japan Company Limited). A tensile test was performed at a tensile speed of 200 mm / min. From the obtained strain-stress curve, Young's modulus was determined from the slope of the straight portion during the initial stretching phase. Tensile breaking strength and tensile breaking elongation were defined as the strength and elongation at the time the sample fractured, respectively.

[0110] (Hayes) Only the obtained sealant film was measured using a direct-reading haze meter manufactured by Toyo Seiki Seisakusho Co., Ltd., in accordance with JIS-K-7105. Haze (%) = [Td (diffuse transmittance %) / Tt (total light transmittance %)] x 100

[0111] (liquid repellency) The liquid-repellent properties of the obtained sealant film were evaluated as follows. (1) Cut a sealant film to a size of 10 cm in the length direction and 5 cm in the width direction. Apply double-sided tape (Nichiban Co., Ltd., NW-5, 5 mm wide) to the surface of the laminate layer at one end of the length direction and the adjacent end of the width direction. Fold the film in the center of the width direction so that the sealed side is facing outwards, and stick the double-sided tape to the other surface of the laminate layer to create a cylindrical strip measuring 10 cm x 2.5 cm. (2) The weight of the cylindrical strips prepared in (1) was measured. (3-1) Each of the evaluation solutions listed below was placed in a 100ml dispensing cup to approximately 70% of its volume. The weighed cylindrical strips were immersed in the evaluation solution for 1 second, with the bottom immersed to a position of 5.6 cm. Inserting a metal ruler or similar object as a support through the opening of the cylindrical strip during immersion makes handling easier and prevents accidentally immersing the opening of the bag into the evaluation solution. Evaluation liquids: Edible oil (product name: Nissin Salad Oil, manufactured by Nissin Oillio Group Ltd.), Tonkatsu sauce (product name: Rich Sauce, manufactured by Kagome Co., Ltd.), Soy sauce (product name: Dark Soy Sauce (Naturally Brewed), manufactured by Kikkoman Foods Corporation). (3-2) With the evaluation liquid still attached to the cylindrical strip, the strip was suspended for 10 seconds with its longitudinal direction vertical, and then suspended for 50 seconds with its width horizontal and its longitudinal direction tilted at a 45° angle to the horizontal. (4) The weight of the cylindrical strip with the evaluation liquid attached immediately after (3-2) was weighed, and the amount of residual liquid attached was determined from the difference between this weight and the weight in (2). The surface area of ​​the cylindrical strip from its bottom to a position 5.6 cm was 28 cm². 2 That is the case. Two or more of the three evaluation solutions yielded a result of 0.08 / 8cm². 2 If it exceeds this, it is considered inferior (×), and if two types are 0.08 / 8cm 2 In the following cases, ○ is good, and all three types are 0.08 / 8cm. 2 The following cases were marked with a "◎" (excellent).

[0112] (Observation of the dispersion state of silylated polyolefins) The surface of the sealant layer of the obtained sealant film was observed using a scanning electron microscope, and elemental qualitative analysis of the surface was performed by irradiating it with energy-dispersive X-rays, and the surface was mapped. The cross-section was also observed using a transmission electron microscope. The observation methods are described in detail below.

[0113] (Energy dispersive X-ray (EDX) elemental qualitative analysis) A sample of the obtained sealant film (1 cm x 1 cm) was cut out, placed on a sample stage covered with carbon tape, and coated with approximately 2 nm of platinum-palladium using a magnetron sputtering apparatus to ensure conductivity. The sample was then observed in high vacuum mode. Measurements were performed using a Hitachi S-3400N scanning electron microscope and a Bruker XFlash5010 energy-dispersive X-ray detector, irradiated with X-rays at an acceleration voltage of 8kV, and then analyzed. Qualitative elemental analysis was performed on the X-ray spectrum of the entire observation field of the sealant film sample. Of the elements identified, carbon (C) was mapped in red and silicon (Si) in green.

[0114] (Transmission electron microscope (TEM) observation) The resulting sealant film (1 cm x 1 cm) was coated with osmium vapor deposition on both sides, treated to prevent peeling from the epoxy resin, and then embedded in the epoxy resin. The embedded sample was cut perpendicular to the film plane using a cryomicrotome set to -130°C, and ultrathin sections were obtained while the sample was frozen. The cross-section was stained in ruthenium tetroxide vapor for 30 minutes, then carbon deposition was performed, and the cross-section was observed and photographed using a JEOL JEM2100 transmission electron microscope at an acceleration voltage of 200kV.

[0115] (Coefficient of kinetic friction) The coefficient of dynamic friction between each film surface of the polyethylene resin sealant film was measured in accordance with JIS-K-7125, except for the conditions specified below. Environmental conditions: Measurements were taken after 2 hours or more of humidity control under conditions of 23°C and 50% RH. Measuring device: Toyo Baldwin TENSILON STM-T-50BP Measurement conditions: Size of the fixed test specimen: 297 mm (longitudinal direction) x 105 mm (width direction) Size of the movable test specimen: 70mm (longitudinal direction) x 50mm (width direction) Mass of the load weight: 0.5 kg Crosshead speed: 20 mm / min Distance traveled: 100mm or more Calculation method: The average test force between strokes of 10 mm and 50 mm and the mass of the load weight were used to calculate the value using the following formula. Coefficient of friction = Average test force for strokes of 10mm to 40mm / Mass of the load weight

[0116] (Coefficient of static friction) The static friction coefficient was measured for each film surface of the polyethylene resin sealant film, in accordance with JIS-P-8147, except for the conditions described below. Environmental conditions: Measurements were taken after 2 hours or more of humidity control under conditions of 23°C and 50% RH. Measuring device: Friction measuring machine AN, manufactured by Toyo Seiki Seisakusho Co., Ltd. Measurement conditions: Specimen size: 200mm (length) x 100mm (width) Weight dimensions: 100mm (length) x 60mm (width) Mass of the load weight: 1.0 kg Tilt speed: 1.5° / sec Measurement method: One test specimen was fixed to an inclined plate, and the other test specimen, with a weight attached, was gently placed on top. The inclined plate was then tilted at a constant speed, and the tangent (tanθ) of the angle at which the weighted test specimen began to slide was calculated and used as the static friction coefficient. The test was performed three times, and the average value was calculated.

[0117] (Blocking value) Except for the following conditions, the sealant layer surfaces of the sealant film were treated with ASTM The blocking value was measured in accordance with D1893-67. A sample with its measurement surface overlapping (10 cm wide, 15 cm long) is placed on a heat press (Tester Industries Co., Ltd., model: SA-303) so that the edge of a 7 cm x 7 cm aluminum plate (2 mm thick) is aligned with the center of the sample width (10 cm) and 1 cm inward along the length (15 cm). The temperature is 50°C and the pressure is 440 kgf / cm². 2 Then, a pressurized treatment was performed for 15 minutes. The sample blocked by this pressurization process and a bar (6mm diameter, aluminum) were mounted on an Autograph (Shimadzu Corporation, model: UA-3122), and the force required for the bar to peel off the blocked area at a speed of 100m / min was measured. In this case, it is assumed that the bar and the peeling surface are horizontal. Four measurements were taken for the same sample, and the average value is displayed.

[0118] (Easy peel) Easy-peel properties were defined as the easy-peel strength after sealing at 190°C. A strength of 20mN / 15mm or less was rated as excellent (◎), 30mN / 15mm or less as good (〇), and anything exceeding 30mN / 15mm as poor (×).

[0119] (Easy-peel strength: mN / 15mm) A dry laminating adhesive (TM569, CAT-10L) manufactured by Toyo Morton was applied to the corona surface of a nylon film (Toyobo's biaxially oriented nylon film: N1100, 15 μm) at a solid content of 3 g / m². 2 The film was applied in this manner, and after the solvent was evaporated in an 80°C oven, the corona surface of the sealant film and the adhesive-coated surface of the nylon film were nipped and laminated on a temperature-controlled roll at 60°C. The laminated film was aged at 40°C for two days, and the laminated film was collected. The sealant surface of the collected laminated film was placed on top of a 300 μm unstretched CPP sheet (WF577PG × 100%), and heat sealing was performed with a seal width of 15 mm, a seal pressure of 0.2 MPa, a seal time of 1.0 second, and seal temperatures of 150, 190°C, and 200°C. A test specimen was obtained by heat-sealing the resulting laminate and arranging it so that its width was 15 mm parallel to the longitudinal direction. These test specimens were placed in an Autograph (Shimadzu Corporation, Model: UA-3122) and the seal surface was peeled off at a speed of 200 mm / min, and the maximum value was measured. Three test specimens were measured at each sealing temperature, and the average value was defined as the easy-peel strength at each sealing temperature.

[0120] (Peel strength: mN / 15mm) A dry laminating adhesive (TM569, CAT-10L) manufactured by Toyo Morton was applied to the corona surface of a nylon film (Toyobo's biaxially oriented nylon film: N1100, 15 μm) at a solid content of 3 g / m². 2 The film was applied in this manner, and after the solvent was evaporated in an 80°C oven, the corona surface of the sealant film and the adhesive-coated surface of the nylon film were nipped and laminated on a temperature-controlled roll at 60°C. The laminated film was aged at 40°C for two days, and the laminated film was collected. The collected laminated films were heat-sealed with the longitudinal directions aligned and the sealant films facing each other, using a seal width of 15 mm, seal pressures of 0.2, 0.4, and 0.6 MPa, a seal time of 1.0 second, and seal temperatures of 150, 190°C, and 200°C. A test specimen was obtained by heat-sealing the resulting laminate and arranging it so that its width was 15 mm parallel to the longitudinal direction. These test specimens were placed in an Autograph (Shimadzu Corporation, Model: UA-3122) and the seal surface was peeled off at a speed of 200 mm / min, and the maximum value was measured. Three test specimens were measured at each sealing temperature, and the average value was taken as the peel strength at each sealing temperature.

[0121] The following raw materials were used in the examples and comparative examples. (Polypropylene resin) (1) WF577PG (ethylene copolymer polypropylene, manufactured by Sumitomo Chemical Co., Ltd., MFR 3.2g / 10min, melting point 142℃) (2) EP3721 (propylene-ethylene block copolymer, manufactured by Sumitomo Chemical Co., Ltd., MFR 2.5g / 10min, melting point 143℃) (2) (Polyethylene resin) (1) F222 (Low-density polyethylene, manufactured by Ube Maruzen Polyethylene Co., Ltd., density 922 kg / m³) 3 (MFR 2.0g / 10min, melting point 110℃) (2) FV407 (metallocene-based linear low-density polyethylene, manufactured by Sumitomo Chemical Co., Ltd., density 930 kg / m³) 3 (MFR 3.2g / 10min, melting point 124℃) (3) A-4070S (Ethylene-α-olefin copolymer, manufactured by Mitsui Chemicals, Inc., density 870 kg / m³) 3 (MFR 3.6g / 10min, melting point 55℃) (4) A-1085S (Ethylene-α-olefin copolymer, manufactured by Mitsui Chemicals, Inc., density 885 kg / m³) 3 (MFR 1.2g / 10min, melting point 66℃) (5) RS1405 (a mixture of ethylene-α-olefin copolymer, manufactured by Mitsui Chemicals, Inc.) (6) P0480 (Ethylene-α-olefin copolymer, manufactured by Mitsui Chemicals, Inc., MFR 1.8g / 10min)

[0122] (Silylated polyolefin resin) (1) Exfora PP2000 (manufactured by Mitsui Chemicals Fine Co., Ltd., contains 30% by weight of silylated polyprefin (olefin-silicone copolymer) and 70% by weight of polypropylene, density 917 kg / m³) 3 (1) MFR 20g / 10min, melting point 125℃ and 160℃) (2) Exfora PE3027 (manufactured by Mitsui Chemicals Fine, Inc., contains 30% by weight of silylated polyprefin (olefin-silicone copolymer), contains 70% by weight of low-density polyethylene, density 932kg / m³) 3 (MFR 30g / 10min, melting points 114℃ and 122℃) (3) Exfora LL1513 (manufactured by Mitsui Chemicals Fine Co., Ltd., contains 30% by weight of silylated polyprefin (olefin-silicone copolymer) and 70% by weight of metallocene-based linear low-density polyethylene, density 921 kg / m³) 3 (MFR 15g / 10min, melting points 102℃ and 121℃)

[0123] (Particles made of inorganic oxides) (1) / (2) / (3) = 90 / 6 / 4 (weight %) mixed pellets (MB) (1) WF577PG (ethylene copolymer polypropylene) (2) KMP-130-10 (spherical silica particles, manufactured by Shin-Etsu Silicone Co., Ltd., weight-average particle size 10 μm) (3) KMP-130-4 (spherical silica particles, manufactured by Shin-Etsu Silicone Co., Ltd., weight-average particle size 10 μm)

[0124] (Organic lubricant) (1) MS07 (contains 5% by weight of erucic acid amide, manufactured by Sumitomo Chemical Co., Ltd.)

[0125] (Examples 1-12) Polypropylene resin, polyethylene resin, silylated polyolefin, spherical silica, diatomaceous earth, ethylene bisoleic acid amide, and erucic acid amide were mixed and melted in a twin-screw extruder to achieve the content ratios (weight %) shown in Table 1, and a seal layer was formed.

[0126] Furthermore, polypropylene resin and erucic acid amide were mixed and melted in a twin-screw extruder to form an intermediate layer, with the content ratio (by weight) shown in Table 1.

[0127] Furthermore, as shown in Table 1, polypropylene resin was melted in a twin-screw extruder to form a laminate layer.

[0128] Using a multilayer film molding apparatus, the molten sealant layer resin composition, the intermediate layer resin composition, and the laminate layer resin composition were laminated together. A single multilayer molten sheet was co-extruded using a T-die, and then cooled and solidified by contacting it with a cooling roll to obtain an unstretched sheet. The surface of the laminate layer of the obtained sheet was subjected to corona discharge treatment, and then wound into a roll at a speed of 20 m / min to obtain a sealant film with a thickness of 60 μm and a wet tensile strength of 45 N / m on the laminate layer surface. The detailed conditions are as follows. Extruder diameter for sealant layer: 60mm Diameter of the extruder for the intermediate layer: 90 mm Diameter of the extruder for the laminate layer: 45 mm Mixing and melting temperature of the raw materials for the sealant layer, intermediate layer, and laminate layer: 250 °C Width of the T-die: 1600 mm Take-up speed of the multi-layer molten sheet: 20 m / min Cooling roll temperature: 40 °C Thickness of the sealant layer in the film for the sealant: 6 μm thickness Thickness of the intermediate layer in the film for the sealant: 42 μm Thickness of the laminate layer in the film for the sealant: 12 μm Note that the longitudinal direction means the direction in which the unstretched sheet travels, and the width direction means the direction perpendicular to it. The properties of the obtained film are shown in Table 2.

[0129] The films for the sealant obtained in Examples 1 to 13 were excellent in liquid repellency and heat sealability. They were also excellent in easy peelability. Moreover, the resin composition used for the seal layer had little precipitation of compounds and was also excellent in film-forming processability. The reason for this is that the silylated polyolefin used for the seal layer has a dimethylsiloxane component, so its surface energy is small and it segregates on the surface of the seal layer. Figure 1 shows the values of the average Si concentration and the surface Si concentration of the films described in Comparative Examples 1, 4, and Examples 2 to 4, 13. It can be seen that the Si concentration of the films described in Comparative Examples 1, 4, and Examples 2 to 4, 13 is about 46.5 times higher at the surface of the seal layer than the average Si concentration of the entire seal layer, indicating that the silylated polyolefin segregates on the surface.

[0130] Figure 3 shows the analysis images of the silicon mapping of the surface of the seal layer in Example 2 and Comparative Example 1. Silicon (green) exists on the entire surface in Example 2, but not in Comparative Example 1. The silica, which is a particle, is emphasized because it has silicon as the main component. Figure 4 shows TEM observation images of the cross-section of the seal layer in Example 2 and Comparative Example 7. Since the silylated polyolefin in Example 2 is a copolymer of dimethylsiloxane and polyethylene, it is difficult for dimethylsiloxane to separate from polyethylene. Although it exhibits a microphase separation structure, it can be seen that it only remains in a finely dispersed state. On the other hand, Comparative Example 7 contains a silicone resin, and phase separation and precipitation thereof are conceivable. Figure 5 is a photograph of the periphery of the die where the seal layer raw materials of Example 2 and Comparative Example 7 were melt-kneaded with a twin-screw extruder. No deposition of the compound was observed in Example 2, and it is considered that the silylated polyolefin in the seal layer does not precipitate on its surface. On the other hand, precipitation of the silicone resin was observed in Comparative Example 7, and there are concerns about foreign substances in the film and deterioration of the working environment.

[0131] (Comparative Examples 1 to 7) A sealant film was obtained in the same manner as in Example 1, except that the compounds shown in Table 1 were used as raw materials for the resin compositions of the seal layer, the laminate layer, and the intermediate layer.

[0132] The sealant film obtained in Comparative Example 1 was inferior in liquid repellency and easy peelability.

[0133] The sealant film obtained in Comparative Example 2 was excellent in liquid repellency but inferior in easy peelability.

[0134] The sealant film obtained in Comparative Example 3 was inferior in liquid repellency.

[0135] The sealant film obtained in Comparative Example 4 was excellent in liquid properties but inferior in easy peelability.

[0136] The sealant film obtained in Comparative Example 5 was excellent in liquid repellency but inferior in easy peelability.

[0137] The sealant film obtained in Comparative Example 6 was excellent in liquid repellency but inferior in easy peelability. Although it exhibited excellent liquid repellency and had low blocking and friction coefficient values, compounds tended to precipitate from the seal layer, making it inferior as a sealant film.

[0138] The sealant film obtained in Comparative Example 7 had excellent liquid properties, but poor ease-peel properties. Although it exhibited excellent liquid repellency and had low blocking and friction coefficient values, compounds tended to precipitate from the seal layer, making it inferior as a sealant film.

[0139] [Table 1]

[0140] [Table 2] [Industrial applicability]

[0141] The sealant film of the present invention is easy to remove even when the contents are viscous, such as pastes or viscous substances, and provides a sealant film and laminate thereof that have good heat sealability and excellent easy-peel properties, making a significant contribution to the industry.

Claims

1. A film comprising a sealing layer made of a resin composition containing (a), (b), and (c) below, wherein a laminate is formed by laminating a sealant film satisfying (1), (2), and (3) below with at least a stretched polyamide film. (a) Polypropylene resin (b) Polyethylene resin (c) Silylated polyethylene resin (1) The content of (a), (b), and (c) is 30-70% by weight, 10-40% by weight, and 3-30% by weight, respectively, relative to the total resin composition. (2) Silylated polyethylene resin is represented by the following formula. CH ３ -(CH ２ ) ｎ－２ -CH ２ -S ｉ (CH ３ ) ２ O-(-S ｉ (CH ３ ) ２ -O-) ｄ -S ｉ (CH ３ ) ２ -CH ２ -(CH ２ ) ｎ－２ -CH ３ (In the formula, d is an integer greater than or equal to 1, and n is an integer greater than or equal to 100.) (3) The polyethylene resin is high-pressure low-density polyethylene.

2. A film comprising a sealing layer made of a resin composition containing (a), (b), and (c) below, wherein a laminate is formed by laminating a sealant film satisfying (1), (2), and (3) below with at least a stretched polyamide film. (a) Polypropylene resin (b) Polyethylene resin (c) Silylated polyethylene resin (1) The content of (a), (b), and (c) is 30-70% by weight, 28-40% by weight, and 3-30% by weight, respectively, relative to the entire resin composition. (2) Silylated polyethylene resin is represented by the following formula. CH ３ -(CH ２ ) ｎ－２ -CH ２ -S ｉ (CH ３ ) ２ O-(-S ｉ (CH ３ ) ２ -O-) ｄ -S ｉ (CH ３ ) ２ -CH ２ -(CH ２ ) ｎ－２ -CH ３ (In the formula, d is an integer greater than or equal to 1, and n is an integer greater than or equal to 100.) (3) The polyethylene resin is linear low-density polyethylene.

3. A film comprising a seal layer made of a resin composition containing (a), (b), and (c) below, wherein a laminate is formed by laminating a sealant film satisfying (4), (5), and (6) below with at least a stretched polyamide film. (a) Polypropylene resin (b) Polyethylene resin (c) Silylated polyethylene resin (4) The content of (a), (b), and (c) is 30 to 85% by weight, 30 to 40% by weight, and 3 to 30% by weight, respectively, relative to the total resin composition. (5) Silylated polyethylene resin is represented by the following formula. CH ３ -(CH ２ ) ｎ－２ -CH ２ -S ｉ (CH ３ ) ２ O-(-S ｉ (CH ３ ) ２ -O-) ｄ -S ｉ (CH ３ ) ２ -CH ２ -(CH ２ ) ｎ－２ -CH ３ (In the formula, d is an integer greater than or equal to 1, and n is an integer greater than or equal to 100.) (6) The polyethylene resin is an elastomer consisting of a copolymer of ethylene monomer and α-olefin.

4. The laminate according to any one of claims 1 to 3, wherein the resin composition contains particles made of an inorganic oxide or a synthetic resin.

5. The laminate according to any one of claims 1 to 3, wherein the resin composition contains a fatty acid amide.

6. A container made of a laminate as described in claim 5.

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