Sealant films and packaging materials

Abstract

The present invention provides a sealant film including a base material layer, an intermediate layer, and a seal layer, wherein the intermediate layer contains linear low-density polyethylene and an ethylene - α-olefin copolymer, the seal layer contains linear low-density polyethylene and high-density polyethylene, and an MFR of the resin constituting the base material layer and the intermediate layer is less than 3.0 g / 10 min (190°C, 21.18 N). The invention also provides a laminate using the sealant film as a sealant, a packaging material including the laminate, and the packaging material that is a packaging material for retort food.

Description

Technical Field

[0001] The present invention relates to a sealant film used for retort packaging and the like that can be sterilized and cooked by heating or pressurization in a state where food or the like is packaged, and a packaging material using the sealant film.

Background Art

[0002] As a food packaging material, flexible packaging using a plastic material is globally used and is showing an increasing trend with the spread to emerging countries. Among these, retort foods sterilized by pressurization and heating (retort sterilization) at high temperatures are expected to have an increasing demand in the future food packaging market due to their convenience. Retort foods can be distributed at room temperature, and in addition to the ease of eating, they are also easy to handle in distribution, and expansion to regions where the development of the cold chain is insufficient is also expected. In addition, since retort foods are distributed at room temperature for a long time, their packaging materials are particularly required to have excellent impact resistance at low temperatures during transportation.

[0003] As a film for food packaging for semi-retort (sterilization treatment at around 120 °C), films using ethylene-based resins have been proposed (for example, Patent Documents 1 and 2). However, there has been a demand for a food packaging material for semi-retort that satisfies further low-temperature impact resistance and retort strength.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide a sealant film that satisfies good low-temperature impact resistance and retort resistance, and a packaging material for retort packaging using the sealant film.

Means for Solving the Problem

[0006] The present invention includes a base material layer, an intermediate layer, and a seal layer, where the intermediate layer contains linear low-density polyethylene and an ethylene-α-olefin copolymer, the seal layer contains linear low-density polyethylene and high-density polyethylene, and the above problem is solved by a sealant film in which the melt flow rate (MFR) of the resins constituting the base material layer and the intermediate layer is less than 3.0 g / 10 min (190 °C, 21.18 N).

[0007] Further, the present invention discloses the following. (1) A sealant film including a base material layer, an intermediate layer, and a seal layer, where the intermediate layer contains linear low-density polyethylene and an ethylene-α-olefin copolymer, the seal layer contains linear low-density polyethylene and high-density polyethylene, and the melt flow rate (MFR) of the resins constituting the base material layer and the intermediate layer is less than 3.0 g / 10 min (190 °C, 21.18 N). (2) The sealant film according to (1), wherein the ethylene-α-olefin copolymer is contained in an amount of 5 to 30% by mass of the total amount of resin components contained in the entire sealant film. (3) The sealant film according to (1), wherein the base material layer contains linear low-density polyethylene and the melt flow rate (MFR) of the linear low-density polyethylene is less than 3.0 g / 10 min (190 °C, 21.18 N). (4) The sealant film according to (1), wherein the high-density polyethylene is contained in an amount of 8.5 to 19.0% by mass of the total amount of resin components contained in the entire sealant film. (5) A laminate having the sealant film according to (1) to (4) as a sealant. (6) A packaging material containing the laminate according to (5). (7) The packaging material described in (6) for retort packaging of food products.

[0008] The sealant film of the present invention, with the above configuration, satisfies excellent low-temperature impact resistance and retort resistance. For this reason, packaging materials using the sealant film of the present invention can be suitably used for packaging various foods and other products, particularly for semi-retort packaging. [Modes for carrying out the invention]

[0009] The sealant film of the present invention comprises a base layer, an intermediate layer, and a sealing layer. The intermediate layer comprises linear low-density polyethylene and ethylene-α-olefin copolymer. The sealing layer comprises linear low-density polyethylene and high-density polyethylene. The MFR of the resin constituting the base layer and the intermediate layer is less than 3.0 g / 10 min (190°C, 21.18 N). It is a sealant film.

[0010] <Base material layer> The base layer of the sealant film of the present invention is a layer that forms a surface that is not a sealing layer, and is a layer that is bonded (laminated) to the base film. Preferably, the base layer is a layer that contains ethylene resin as the main resin component. The content of ethylene resin is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 65% ​​by mass or more, of the resin components contained in the base layer, in order to easily obtain suitable impact resistance. Furthermore, the resin components contained in the base layer may be substantially only ethylene resin, but when other resins are used in combination, the content of ethylene resin is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less.

[0011] Examples of the above-mentioned ethylene-based resins include polyethylene resins such as ultra-low density polyethylene (VLDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), linear medium density polyethylene (LMDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE), as well as ethylene-based copolymers such as ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA). These ethylene-based resins may be used individually or in mixtures of two or more. Among these, linear low density polyethylene and high density polyethylene are preferred for the base layer because they easily provide suitable impact resistance and good heat resistance.

[0012] The density of the above-mentioned ethylene-based resin is preferably 0.960 g / cm³, as this makes it easier to obtain good heat resistance and impact resistance. 3 More preferably, 0.950 g / cm³ 3 The following applies. Also, 0.900 g / cm³ 3 Preferably, it should be 0.910 g / cm³ or more. 3 It is more preferable that the values ​​are as described above. The MFR (melt flow rate) of the ethylene resin is 0.1 to 50 g / 10 min (190°C, 21.18 N), preferably 0.5 to 30 g / 10 min (190°C, 21.18 N), and more preferably 1 to 20 g / 10 min (190°C, 21.18 N). An MFR within this range is preferable because it allows for good film formation. Furthermore, when linear low-density polyethylene is used for the base layer, the MFR of the linear low-density polyethylene is preferably less than 3.5 g / 10 min, and more preferably less than 3.0 g / 10 min. When the MFR is within this range, the impact resistance is particularly excellent.

[0013] When using high-density polyethylene as the ethylene-based resin for the base layer, it is preferable to use high-density polyethylene with an MFR (190°C, 21.18N) of 12 g / 10 min or less, as this makes it easier to obtain suitable impact resistance. More preferably, the MFR is 10 g / 10 min or less, and even more preferably 8 g / 10 min or less. The lower limit is not particularly limited, but it is preferably 0.1 g / 10 min or more, and more preferably 0.5 g / 10 min or more.

[0014] The base layer of the present invention preferably further contains an olefin-based thermoplastic elastomer. Examples of olefin-based thermoplastic elastomers include ethylene-α-olefin copolymers such as ethylene-propylene copolymer rubber (EPR), ethylene-1-butene copolymer rubber (EBR), ethylene-1-pentene copolymer rubber, ethylene-1-hexene copolymer rubber (EHR), and ethylene-1-octene copolymer rubber (EOR); and propylene-1-butene copolymer rubber (PBR), propylene-1-pentene copolymer rubber, and propylene-1-octene copolymer (POR). Among these, ethylene-α-olefin copolymers are preferably used.

[0015] The above-mentioned ethylene-α-olefin copolymer is obtained by copolymerizing ethylene and α-olefin, and is used as a resin modifier. As for α-olefins, α-olefins having 3 to 20 carbon atoms are preferred, propylene, 1-butene, 1-heptene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 2-methyl-1-propene, 2-methyl-1-butene, 3-methyl-1-butene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4- Examples include methyl-1-pentene, 3,3-dimethyl-1-butene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, methylethyl-1-butene, methyl-1-pentene, ethyl-1-hexene, dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, and diethyl-1-butene. Among the α-olefins, propylene, 1-butene, 1-pentene, 1-hexene, and 1-octene are preferred, 1-butene, 1-pentene, and 1-hexene are more preferred, and 1-butene is particularly preferred. In other words, the ethylene-α-olefin copolymer is preferably ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-pentene copolymer, ethylene-hexene copolymer, or ethylene-octene copolymer, more preferably ethylene-butene copolymer, ethylene-pentene copolymer, or ethylene-hexene copolymer, and particularly preferably ethylene-butene copolymer. The α-olefin may be used alone or in combination of two or more types. By using the ethylene-α-olefin copolymer, it is possible to achieve a high level of both impact resistance and heat resistance, resulting in good impact resistance for the sealant film of the present invention and the laminate or packaging material using it.

[0016] The content of structural units derived from α-olefins in the above ethylene-α-olefin copolymer is preferably 5 to 30% by mass, and more preferably 5 to 25% by mass. Furthermore, the content of structural units derived from α-olefins is preferably 5 to 15 mol%.

[0017] The melt flow rate (MFR) of the above ethylene-α-olefin copolymer is preferably 0.5 to 10 g / 10 min (190°C, 21.18 N), but it is more preferably 3 to 10 g / 10 min because it is easier to obtain suitable tear properties.

[0018] The density of ethylene-α-olefin copolymer is 0.850 to 0.930 g / cm³. 3 This is preferable. The appropriate material should be selected according to the purpose, such as impact resistance, or achieving both impact resistance and rigidity. In particular, if you want to improve impact resistance, 0.850~0.920 g / cm² is preferable. 3 It is preferable that this be the case.

[0019] The content of the ethylene-α-olefin copolymer is preferably 1% to 39% by mass, more preferably 1% to 35% by mass, and even more preferably 5% to 30% by mass, relative to the total amount of resin components contained in the base layer. Within this range, impact resistance at low temperatures is good.

[0020] The base layer of the sealant film of the present invention can use various resins other than the ethylene-based resins mentioned above, including those used in packaging films, and among these, olefin-based resins such as propylene-based resins are preferably used. As the propylene-based resin, propylene homopolymers, propylene-α-olefin random copolymers, propylene-α-olefin block copolymers, etc., can be used. These may be used individually or in combination.

[0021] When an olefin resin other than the above-mentioned ethylene-based resin is used as the resin component for the base layer, its content is preferably 30% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less of the resin component contained in the base layer.

[0022] Furthermore, cyclic polyolefin resins may be used as olefin resins other than the ethylene-based resins mentioned above, but the content of cyclic polyolefin resins in the resin components contained in the base layer is preferably 10% by mass or less, more preferably 5% by mass or less, and preferably not used at all. Examples of the cyclic olefin resin include norbornene polymers, vinyl alicyclic hydrocarbon polymers, and cyclic conjugated diene polymers. Among these, norbornene-based polymers are preferred. Furthermore, examples of norbornene polymers include ring-opening polymers (COP) of norbornene monomers and norbornene copolymers (COC) obtained by copolymerizing norbornene monomers with olefins such as ethylene. Furthermore, hydrogenated COP and COC are also particularly preferred. Furthermore, the weight-average molecular weight of the cyclic olefin resin is preferably 5,000 to 500,000, and more preferably 7,000 to 300,000.

[0023] The norbornene polymers and norbornene monomers used as raw materials are alicyclic monomers having a norbornene ring. Examples of such norbornene monomers include norbornene, tetracyclododecene, ethylidenenorbornene, vinylnorbornene, ethylidetetracyclododecene, dicyclopentadiene, dimethanotetrahydrofluorene, phenylnorbornene, methoxycarbonylnorbornene, and methoxycarbonyltetracyclododecene. These norbornene monomers may be used individually or in combination of two or more.

[0024] The above norbornene copolymer is obtained by copolymerizing a norbornene monomer with an olefin copolymerizable therewith. Examples of such olefins include olefins having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene; cycloolefins such as cyclobutene, cyclopentene, cyclohexene; non-conjugated dienes such as 1,4-hexadiene, etc.

[0025] In the base material layer used in the present invention, other resins other than the above may be used in combination. Examples of such other resins include thermoplastic elastomers such as ethylene-vinyl acetate copolymer (EVA), butene-based elastomers; ethylene-based copolymers such as ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA); furthermore, ionomers of ethylene-acrylic acid copolymers, ionomers of ethylene-methacrylic acid copolymers, etc. can be exemplified.

[0026] When using the above other resins, it is preferably used at a content of 30% by mass or less in the resin components contained in the base material layer, more preferably 20% by mass or less, still more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0027] As the above ethylene-based resin, biomass-derived polyethylene may be used. For example, biomass-derived low-density polyethylene (trade name: SBC818, density: 0.918 g / cm 3 , MFR: 8.1 g / 10 min) manufactured by Braskem, biomass-derived low-density polyethylene (trade name: SPB681, density: 0.922 g / cm 3 , MFR: 3.8 g / 10 min) manufactured by Braskem, biomass-derived linear low-density polyethylene (trade name: SLL118, density: 0.916 g / cm 3Examples include MFR: 1.0g / 10 mins.

[0028] In addition to the resin component mentioned above, various additives may be appropriately used in combination in the substrate layer of the sealant film of the present invention. Examples of additives include antioxidants, weather stabilizers, antistatic agents, antifogging agents, antiblocking agents, lubricants, nucleating agents, pigments, biodegradability-promoting additives, and compatibilizers. When using these additives, they are preferably used in amounts of 10 parts by mass or less, and more preferably 8 parts by mass or less, per 100 parts by mass of the resin component used in the base layer.

[0029] In particular, in order to provide processability during film formation and packaging suitability for filling machines, the friction coefficient of the base layer and seal layer that form the surface of the sealant film of the present invention is preferably 1.5 or less, and more preferably 1.0 or less. Therefore, it is preferable to appropriately add lubricants and antiblocking agents to the base layer and seal layer.

[0030] The thickness ratio of the base layer to the total thickness of the sealant film of the present invention is preferably in the range of 5 to 50%, and particularly preferably in the range of 10 to 45%, in order to obtain suitable heat resistance and excellent impact resistance at low temperatures.

[0031] The MFR of the resin component contained in the above-mentioned base layer is less than 3.0 g / 10 min. When the MFR is within this range, the appearance after retorting and impact resistance at low temperatures are excellent. Furthermore, the MFR of the resin component contained in the base layer is preferably less than 2.5 g / 10 min, more preferably less than 2.0 g / 10 min, and even more preferably less than 1.8 g / 10 min, as this provides particularly excellent impact resistance at low temperatures. In addition, there is no particular lower limit to the MFR of the resin component contained in the base layer, but it is preferably 0.1 g / 10 min or more, and more preferably 0.5 g / 10 min or more. Note that the MFR is the value at 190°C and 21.18 N, and the MFR of the resin component contained in the base layer can be calculated using the following formula based on the MFR of each resin contained in the base layer. MFR calculation value = 1 / (W1 × (1 / MFR1) + ... + W) n ×(1 / MFR n ))...(Formula 1) MFR1: MFR of the first resin contained in the substrate layer (190℃, 21.18N) MFR n : MFR of the nth resin contained in the substrate layer (190℃, 21.18N) W1: Mass ratio of the first resin to the total resin components contained in the base layer. W n : The mass ratio of the nth resin to the total resin components contained in the base layer. (However, W1 + ... + W n =1) Furthermore, the average density of the resin components contained in the above-mentioned base material layer is 0.920 g / cm³. 3 The above is preferable because it allows for the achievement of suitable retort resistance. The average density is 0.928 g / cm³. 3 Preferably, it should be 0.930 g / cm³ or more. 3 It is more preferable to have a value of 0.931 g / cm³ or higher. 3 It is even more preferable to set it to the above. Also, since it is easier to obtain a suitable impact strength, 0.950 g / cm 3 Preferably, it should be 0.945 g / cm³. 3 The following is more preferable.

[0032] <Middle class> The intermediate layer in the sealant film of the present invention comprises linear low-density polyethylene and an ethylene-α-olefin copolymer. Furthermore, the MFR of the resin constituting the intermediate layer is less than 3.0 g / 10 min (190°C, 21.18 N).

[0033] The linear low-density polyethylene (LLDPE) mentioned above is a copolymer of ethylene and α-olefin polymerized using a multi-site catalyst, such as the Ziegler-Natta catalyst, or a single-site catalyst, such as the metallocene catalyst, and has a density of 0.950 g / cm³. 3 This refers to substances less than [a certain value]. Alpha-olefins that serve as comonomers for linear low-density polyethylene have 3 or more carbon atoms, and examples include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 4-methylpentene, 3,3-dimethylbutene, and mixtures thereof.

[0034] The density of the above linear low-density polyethylene is 0.900 to 0.945 g / cm³. 3 Preferably, it is 0.910 to 0.945 g / cm³. 3 It is more preferable that the linear low-density polyethylene contains 0.5 to 10% by mass of constituent units derived from α-olefins, and more preferably 1 to 8% by mass. Furthermore, it is preferable that the content of constituent units derived from α-olefins is 0.1 to 10 mol%.

[0035] The ethylene-α-olefin copolymer used in the above-mentioned substrate layer can be the same as the ethylene-α-olefin copolymer preferably used in the above-mentioned substrate layer, and the preferred range is also the same. Specifically, as the ethylene-α-olefin copolymer used in the intermediate layer, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-pentene copolymer, ethylene-hexene copolymer, and ethylene-octene copolymer are preferred, ethylene-butene copolymer, ethylene-pentene copolymer, and ethylene-hexene copolymer are more preferred, and ethylene-butene copolymer is particularly preferred. The α-olefin may be used alone or in combination of two or more types.

[0036] The melt flow rate (MFR) of the above ethylene-α-olefin copolymer is preferably 0.1 to 10 g / 10 min (190°C, 21.18 N), and more preferably 0.5 to 10 g / 10 min.

[0037] The density of ethylene-α-olefin copolymer is 0.850 to 0.943 g / cm³. 3 This is preferable. The appropriate amount can be selected according to the purpose of modifying the propylene-based block copolymer, such as impact resistance, or achieving both impact resistance and rigidity. In particular, if you want to improve impact resistance, 0.850 to 0.920 g / cm³ is preferable. 3 It is preferable that this be the case.

[0038] The content of the ethylene-α-olefin copolymer is preferably 1% to 50% by mass, more preferably 1% to 30% by mass, even more preferably 2% to 20% by mass, and particularly preferably 5% to 20% by mass, relative to the total amount of resin components in the intermediate layer. Within this range, impact resistance at low temperatures is good. In this specification, a density of 0.900 g / cm³ is used. 3 A copolymer of ethylene and α-olefin with a density of less than 0.900 g / cm³. 3 The copolymers of ethylene and α-olefins described above are distinguished from linear low-density polyethylene.

[0039] The above-mentioned intermediate layer may further contain an ethylene-based resin. The ethylene-based resin used may be the same as the ethylene-based resin exemplified in the base layer, and may be used alone or in a mixture of two or more types. The preferred type of ethylene-based resin, density, and preferred range of melt flow rate are also the same as those for the base layer.

[0040] As the ethylene-based resin, the biomass-derived polyethylene described above may be used.

[0041] Other resins besides the ethylene-based resins and olefin-based thermoplastic elastomers may be used in combination as the resin component of the intermediate layer. Examples of such other resins include olefin-based resins such as propylene homopolymers, propylene-α-olefin random copolymers such as propylene-ethylene copolymers, propylene-butene-1 copolymers, and propylene-ethylene-butene-1 copolymers, and propylene-α-olefin block copolymers, as well as thermoplastic elastomers such as ethylene-vinyl acetate copolymer (EVA), polypropylene elastomers, and butene elastomers; ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); and further examples include ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers.

[0042] When using other resins as described above, it is preferable that their content be 30% by mass or less of the resin components in the intermediate layer, more preferably 20% by mass or less, even more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0043] Furthermore, as the other resin component used in the intermediate layer, recovered film edges and other materials generated during the manufacture of the sealant film of the present invention and film edges and other materials generated during the manufacture of ethylene-based films may also be mixed. Here, ethylene-based film means a film in which the proportion of the above-mentioned ethylene-based resin in the total resin constituting the film is 70% by mass or more. When the recovered product is added to the intermediate layer, it is preferable to use it in an amount of 1 to 50% by mass of the resin components contained in the intermediate layer, more preferably 5 to 45% by mass, even more preferably 8 to 40% by mass, and still more preferably 10 to 38% by mass. When adding the recovered material, the film edges may be crushed and added as fluff, or the film edges may be kneaded into pellets and then added.

[0044] In addition to the resin component mentioned above, various additives may be appropriately used in combination in the intermediate layer of the sealant film of the present invention. Examples of additives include antioxidants, weather stabilizers, antistatic agents, antifogging agents, antiblocking agents, lubricants, nucleating agents, pigments, and biodegradability-promoting additives. When using these additives, they are preferably used in amounts of 10 parts by mass or less, and more preferably 8 parts by mass or less, per 100 parts by mass of the resin component used in the intermediate layer.

[0045] The sealant film of the present invention has an MFR of less than 3.0 g / 10 min (190°C, 21.18 N) for the resin constituting the intermediate layer. When the MFR is within this range, the appearance after retorting and impact resistance at low temperatures are excellent. Furthermore, it is preferable that the MFR of the resin component contained in the intermediate layer be less than 2.0 g / 10 min, as this provides particularly excellent impact resistance at low temperatures. The lower limit of the MFR of the resin component contained in the intermediate layer is not particularly limited, but it is preferably 0.1 g / 10 min or more, and more preferably 0.5 g / 10 min or more. Note that MFR is the value at 190°C and 21.18 N, and the MFR of the resin component contained in the intermediate layer can be calculated using the above formula based on the MFR of each resin contained in the intermediate layer. Furthermore, the average density of the resin components constituting the intermediate layer is 0.9350 g / cm³. 3 Setting it below this value is preferable because it allows for the achievement of suitable impact strength at low temperatures. The average density is 0.9340 g / cm³. 3 It is more preferable to keep it below 0.9333 g / cm³. 3 It is even more preferable that the average density is less than [a certain value]. When the average density is within a preferred range, the impact strength at low temperatures is good. The average density of the resin components contained in the intermediate layer can be adjusted by changing the density and ratio of the resins contained in the intermediate layer.

[0046] In the intermediate layer, other resins besides the ethylene-based resin described above may also be used. Examples of such other resins include those similar to those used in the base layer, and the preferred content is the same as that of the base layer.

[0047] The ratio of the thickness of the intermediate layer to the total thickness of the sealant film is preferably 90% or less, more preferably 40-80%, and even more preferably in the range of 50-70%, as this facilitates obtaining suitable impact resistance and heat resistance. There is no particular lower limit, but it is preferably 10% or more.

[0048] The sealant film of the present invention may contain two or more intermediate layers. In this case, it is sufficient that one or more of the intermediate layers have the resin composition described above. Furthermore, when there are two or more intermediate layers, the thickness ratio should be within the above range if the thickness ratio of all intermediate layers considered together as one layer is also considered.

[0049] <Seal layer> The sealing layer used in the sealant film of the present invention comprises linear low-density polyethylene and high-density polyethylene. This sealing layer provides both suitable impact resistance and heat resistance.

[0050] The linear low-density polyethylene used in the sealing layer is the same as that used in the intermediate layer, and its preferred range is also the same. Furthermore, the linear low-density polyethylene used in the intermediate layer and the linear low-density polyethylene used in the sealing layer may exhibit similar physical properties or different physical properties.

[0051] The content of linear low-density polyethylene in the resin component contained in the above-mentioned sealing layer is preferably 25 to 75% by mass, more preferably 30 to 70% by mass, and even more preferably 30 to 60% by mass.

[0052] A linear low-density polyethylene with a density of 0.900 g / cm³ is suitable for obtaining desirable impact resistance and heat sealability. 3 More than 0.965g / cm 3 Preferably less than 0.910 to 0.965 g / cm³ 3 It is more preferable that it be less than 0.920 to 0.965 g / cm³. 3 It is even more preferable that it be less than [amount].

[0053] The above-mentioned high-density polyethylene is also called HDPE and has a density of 0.945 g / cm³. 3This refers to polyethylene having the density specified above. It may be a homopolymer of ethylene or a copolymer of ethylene and α-olefin, but since the density decreases as the amount of α-olefin acting as comonomer increases, it is preferable to have fewer comonomers, and specifically, it is preferable that the comonomer ratio is 0.5% or less.

[0054] The high-density polyethylene used is preferably one with an MFR (at 190°C, 21.18N) of 0.01 g / 10 min or higher. More preferably, the MFR is 0.1 g / 10 min or higher, and even more preferably 2 g / 10 min or higher. There is no particular upper limit, but it is preferably 50 g / 10 min or less, and more preferably 20 g / 10 min or less. Using this high-density polyethylene makes it easier to achieve good heat sealability along with suitable low-temperature impact resistance and heat resistance.

[0055] When high-density polyethylene with an MFR of 3.0 g / 10 min or more is used in the sealing layer of the sealant film of the present invention, the content of the high-density polyethylene in the resin component contained in the sealing layer is preferably 25 to 75% by mass, more preferably 30 to 70% by mass, and even more preferably 40 to 60% by mass.

[0056] The above-mentioned sealing layer may also contain other ethylene-based resins. The ethylene-based resins used may be the same as those exemplified in the base layer and intermediate layer, and may be used alone or in a mixture of two or more types. The preferred type of ethylene-based resin, density, and preferred range of melt flow rate are also the same as those for the base layer and intermediate layer. As the ethylene-based resin, the biomass-derived polyethylene described above may be used.

[0057] Other resins besides the linear low-density polyethylene and high-density polyethylene may be used in combination as the resin component of the seal layer. Examples of such other resins include propylene homopolymers, olefin resins such as propylene-α-olefin random copolymers and propylene-α-olefin block copolymers such as propylene-ethylene copolymer, propylene-butene-1 copolymer, and propylene-ethylene-butene-1 copolymer, ethylene-α-olefin block copolymer, thermoplastic elastomers such as ethylene-vinyl acetate copolymer (EVA), polypropylene elastomers, and butene elastomers; ethylene copolymers such as ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); and further examples include ionomers of ethylene-acrylic acid copolymer and ionomers of ethylene-methacrylic acid copolymer.

[0058] As the linear low-density polyethylene, high-density polyethylene, and other ethylene-based resins mentioned above, the biomass-derived polyethylene described above may be used.

[0059] In addition to the resin components mentioned above, various additives may be used in the sealing layer as appropriate. Examples of additives include lubricants, anti-blocking agents, UV absorbers, light stabilizers, anti-static agents, anti-fogging agents, colorants, antioxidants, etc. When using these additives, they should preferably be used in amounts of 10 parts by mass or less, more preferably 8 parts by mass or less, per 100 parts by mass of the resin components used in the sealing layer.

[0060] In particular, in order to provide processability during film formation and packaging suitability for filling machines, the friction coefficient of the base layer and seal layer that form the surface of the sealant film of the present invention is preferably 1.5 or less, and more preferably 1.0 or less. Therefore, it is preferable to appropriately add lubricants and antiblocking agents to the base layer and seal layer.

[0061] The ratio of the thickness of the sealing layer to the total thickness of the sealant film is preferably 2 to 45%, and more preferably in the range of 5 to 40%, as this makes it easier to obtain suitable impact resistance and heat resistance.

[0062] <Sealant film> As described above, the sealant film of the present invention comprises a base layer, an intermediate layer, and a sealing layer, wherein the intermediate layer comprises linear low-density polyethylene and an ethylene-α-olefin copolymer, and the sealing layer comprises linear low-density polyethylene and high-density polyethylene, and the MFR of the resins constituting the base layer and the intermediate layer is less than 3.0, thereby achieving excellent impact resistance at low temperatures and suitable retort resistance at a high level.

[0063] Furthermore, the sealant film of the present invention preferably contains 5 to 30% by mass of the ethylene-α-olefin copolymer relative to the total amount of resin components in the entire sealant film, as this provides an excellent balance between retort resistance and impact strength at low temperatures. Furthermore, it is preferable that the sealant film of the present invention contains 8.5 to 19.0% by mass of high-density polyethylene in the total amount of resin components contained in the entire sealant film, as this allows the sealant film to exhibit good low-temperature impact resistance and retort suitability even with a simple composition achieved by limiting the types of raw materials used. Furthermore, if the sealant film contains recovered material, the content of ethylene-α-olefin copolymer and high-density polyethylene should be calculated by considering the resin composition of the film edge added as recovered material. That is, if the resin composition of the film edge is known, the content of ethylene-α-olefin copolymer and high-density polyethylene contained in the recovered material can be calculated from that known resin composition, and the content of ethylene-α-olefin copolymer and high-density polyethylene relative to the total amount of resin components contained in the entire sealant film can be calculated. On the other hand, if the resin composition of the film edge is unknown, the resin composition of the recovered material should be analyzed in advance using some analytical method such as nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR), or differential scanning calorimetry (DSC). However, since an analytical step is required, in one embodiment of the present invention, it is preferable that the resin composition of the recovered material is known.

[0064] Furthermore, if the sealant film of the present invention contains 90% by mass or more of ethylene-based resin in its resin component, it becomes a monomaterial film, which is preferable because it is easily recyclable and contributes to reducing environmental impact.

[0065] The sealant film of the present invention preferably has a film thickness of 30 to 100 μm, and more preferably 40 to 80 μm. A film thickness within this range makes it easier to obtain excellent impact resistance, rigidity, sealing properties, and suitability for packaging machinery at low temperatures.

[0066] Furthermore, while the thickness of each layer is not particularly limited, for example, the thickness of the base layer is preferably 2.5 to 20 μm, and more preferably 5 to 18 μm. The thickness of the intermediate layer is preferably 4 to 70 μm, and more preferably 6 to 50 μm. The thickness of the sealing layer is preferably 2.5 to 20 μm, and more preferably 5 to 18 μm.

[0067] The sealant film of the present invention may contain two or more intermediate layers. In that case, the layer structure may be, for example, a base layer / intermediate layer / intermediate layer / seal layer, or a base layer / intermediate layer / intermediate layer / seal layer, but the present invention is not limited to these.

[0068] The method for manufacturing the sealant film of the present invention is not particularly limited, but for example, a co-extrusion method is used in which each resin or resin mixture used for the base layer, intermediate layer, and sealing layer is heated and melted in separate extruders, and then laminated in the order of base layer / intermediate layer / sealing layer in the molten state using methods such as the co-extrusion multilayer die method or the feed block method, and then formed into a film using methods such as inflation or the T-die chill roll method. This co-extrusion method is preferred because it allows for relatively free adjustment of the thickness ratio of each layer, and a sealant film with excellent hygiene and cost performance can be obtained.

[0069] Since the sealant film of the present invention is obtained as a substantially unstretched film by the above manufacturing method, secondary molding such as deep drawing by vacuum forming is also possible.

[0070] Furthermore, it is preferable to apply a surface treatment to the substrate layer in order to improve adhesion to printing inks and lamination suitability when used as a sealant film for lamination. Examples of such surface treatments include surface oxidation treatments such as corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, ozone / ultraviolet treatment, or surface roughening treatments such as sandblasting, but corona treatment is preferred.

[0071] (Laminated structure) The sealant film of the present invention can be laminated by bonding it to a substrate or by other means to form a laminate in which the sealant film of the present invention acts as a sealant. The structure of the laminate of the present invention is as follows: (1) Substrate / Adhesive layer / Sealant film of the present invention (2) Substrate / Adhesive layer / Printed layer / Sealant film of the present invention (3) Substrate / Adhesive layer / Second substrate / Printed layer / Adhesive layer / Sealant film of the present invention (4) Substrate / Adhesive layer / First printing layer / Second printing layer / Sealant film of the present invention (5) Substrate / Adhesive layer / Barrier layer / Adhesive layer / Sealant film of the present invention (6) Substrate / Adhesive layer / Barrier layer / Printed layer / Adhesive layer / Sealant film of the present invention (7) Substrate / Printing layer / Adhesive layer / Sealant film of the present invention (8) Substrate / First printing layer / Second printing layer / Adhesive layer / Sealant film of the present invention (9) Substrate / Printing layer / Adhesive layer / Barrier layer / Adhesive layer / Sealant film of the present invention (10) Substrate / Adhesive layer / Barrier layer / Adhesive layer / Second substrate / Adhesive layer / Sealant film of the present invention (11) Substrate / Printing layer / Adhesive layer / Barrier layer / Adhesive layer / Second substrate / Adhesive layer / Sealant film of the present invention Examples include, but are not limited to, additional base materials may be included. In particular, when used as packaging material for retort products, the configurations of (10) and (11) are preferred from the viewpoint of retort suitability. Furthermore, when multiple adhesive layers are included, each adhesive layer may have the same composition or be different, and the thickness of the multiple adhesive layers may be the same or different; there are no particular limitations. The second and additional substrates may be unstretched resin films, stretched resin films, metal-deposited films such as unstretched metal-deposited films or stretched metal-deposited films, or transparent metal-deposited films, and are not particularly limited. Furthermore, the multiple adhesive layers may have the same composition or different compositions. Furthermore, to improve the adhesive strength of the adhesive layer, an anchor coat layer may be sandwiched between the layers. Furthermore, the substrate may have a coating layer that provides functions such as mold release and antistatic properties.

[0072] (base material) The above-mentioned substrates are not particularly limited and include polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, polystyrene film, polyamide film, nylon film, polyacrylonitrile film, polyolefin films such as polyethylene film (OPE: biaxially oriented polyethylene film, LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film) and polypropylene film (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer film, cellophane, and the like.

[0073] Furthermore, films can be used that have inorganic vapor-deposited layers such as film silica or metal oxides like alumina. Specific examples include OPE films, OPP films, PET films, PBT films, and nylon films having a silica vapor-deposited layer, and OPE films, OPP films, PET films, PBT films, and nylon films having an alumina vapor-deposited layer.

[0074] When considering monomaterial packaging, a film made of a thermoplastic resin mainly composed of olefin resin can be used as the base material. Specifically, olefin resins include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; polypropylene; ethylene-propylene copolymer; α-olefin polymer; ethylene-vinyl acetate copolymer; ethylene-vinyl alcohol copolymer; ethylene-acrylic acid copolymer; ethylene-methyl methacrylate copolymer; ethylene-ethyl acrylate copolymer; cyclic olefin resin; ionomer resin; and polymethylpentene; as well as modified olefin resins obtained by modifying olefin resin with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, or other unsaturated carboxylic acids. The sealant film of the present invention can be made into a polyethylene monomaterial film by using the above polyethylene as the base material, which is preferable for reducing environmental impact.

[0075] Furthermore, it is also preferable to use a film made from a material containing biomass-derived components as the film substrate. Biomass films are sold by various companies, and for example, films and sheets listed in the biomass certified product list provided by the Japan Organic Resources Association can be used.

[0076] A well-known example of a film made from biomass-derived ethylene glycol is derived from ethanol produced from biomass (biomass ethanol). For example, biomass-derived ethylene glycol can be obtained by conventionally known methods, such as a method that produces ethylene glycol via ethylene oxide from biomass ethanol. Alternatively, commercially available biomass ethylene glycol may be used; for example, the biomass ethylene glycol commercially available from India Glycol can be suitably used.

[0077] Alternatively, products using biomass raw materials, distinguished by their biomass plasticity as defined by ISO 16620 or ASTM D6866, are also available. Radioactive carbon-14C exists in the atmosphere at a rate of 1 in 10¹² atoms, and this rate does not change even in atmospheric carbon dioxide. Therefore, this rate does not change in plants that fix carbon dioxide through photosynthesis. For this reason, the carbon in plant-derived resins contains radioactive carbon-14C. In contrast, the carbon in fossil fuel-derived resins contains almost no radioactive carbon-14C. Therefore, by measuring the concentration of radioactive carbon-14C in the resin using an accelerator mass spectrometer, the proportion of plant-derived resin in the resin, i.e., the biomass plasticity, can be determined. Examples of plant-derived low-density polyethylene (PDI) biomass plastics with a biomass plastic content of 80% or more, preferably 90% or more, as defined by ISO 16620 or ASTM D6866, include Braskem's product names "SBC818," "SPB608," "SBF0323HC," "STN7006," "SEB853," and "SPB681," and films made from these materials can be suitably used.

[0078] For example, as an alternative to conventional polyolefin films using petroleum-based raw materials, biomass polyolefin films such as biomass polyethylene films and biomass polyethylene-polypropylene films, which contain ethylene resins made from biomass-derived ethylene glycol, are also known. The ethylene-based resin is not particularly limited except for the use of ethylene glycol derived from the biomass mentioned above as part of the raw materials. Examples include ethylene homopolymers, copolymers of ethylene and α-olefins with ethylene as the main component (ethylene-α-olefin copolymers containing 90% by mass or more of ethylene units), and these can be used individually or in combination of two or more. The α-olefin constituting the copolymer of ethylene and α-olefin is not particularly limited, and examples include α-olefins having 4 to 8 carbon atoms, such as 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene. Known polyethylene resins such as low-density polyethylene resin, medium-density polyethylene resin, and linear low-density polyethylene resin can be used. Among these, linear low-density polyethylene resin (LLDPE) (a copolymer of ethylene and 1-hexene, or a copolymer of ethylene and 1-octene) is preferred from the viewpoint of making it even less likely for damage such as punctures or tears to occur when the films rub against each other, and has a density of 0.910 to 0.925 g / cm³. 3 A linear low-density polyethylene resin is more preferable.

[0079] The biomass film may be a laminate formed by stacking multiple biomass films, or it may be a laminate formed by combining a conventional petroleum-based film with a biomass film.

[0080] The above-mentioned substrate may be subjected to some kind of surface treatment, such as physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, or flame treatment, or chemical treatments such as oxidation treatment using chemicals, or other treatments.

[0081] The above-mentioned substrate can be manufactured using conventionally known film formation methods such as extrusion, casting, T-die, cutting, and inflation methods. It may be an unstretched film, or, from the viewpoint of film strength, dimensional stability, and heat resistance, it may be stretched in one or two axes using a tenter method, tubular method, etc.

[0082] The above-mentioned base material may contain additives as needed. Specifically, plastic compounding agents and additives such as elastomers, lubricants, crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, and pigments may be added to improve or modify properties such as processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, mold release properties, flame retardancy, mold resistance, electrical properties, and strength. The amount of additives added should be adjusted within a range that does not affect other properties or recyclability.

[0083] The film thickness of the above-mentioned substrate is not particularly limited and can be appropriately selected within the range of 0.1 to 300 μm from the viewpoint of moldability and transparency. Preferably, it is in the range of 0.3 to 100 μm. If the film thickness of the substrate is 0.1 to 300 μm, good strength and processing stability can be obtained.

[0084] From a recycling perspective, it is preferable that the layer structure be as simple as possible, but from the perspective of the distribution of the packaging material, it may include printing to display the contents of the packaging material, product description, and name.

[0085] (adhesive layer) In the present invention, the adhesive layer has the function of bonding any two layers constituting the laminate, for example, a base material layer and a second base material layer. The adhesive used for the adhesive layer can be any adhesive that can be used in a general lamination method. Examples of lamination methods include dry lamination, wet lamination, non-solvent lamination, extrusion lamination, sand lamination, and heat lamination. After the adhesive hardens or dries, it becomes an adhesive layer.

[0086] As adhesives used in the above dry lamination, for example, one-component or two-component curing or non-curing type adhesives such as vinyl-based, (meth)acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, rubber-based, and others, can be used, including solvent-based, water-based, or emulsion-type adhesives. As a two-component curing type adhesive, a two-component curing adhesive consisting of a polyol and an isocyanate compound can be used. Among the above adhesives, a two-component curing adhesive comprising a polyol composition and a polyisocyanate composition is preferred.

[0087] (Two-part curing adhesive) The above two-component curing adhesive preferably contains a polyisocyanate composition (X) and a polyol composition (Y).

[0088] (Polyisocyanate composition (X)) The above polyisocyanate composition (X) is not particularly limited and can be any polyisocyanate composition (X) used in the adhesive technology field, for example, a urethane prepolymer, a mixture of a urethane prepolymer and an isocyanate compound, and an isocyanate compound can be used.

[0089] (Urethane prepolymer (A1)) The above-mentioned urethane prepolymer (hereinafter sometimes referred to as urethane prepolymer (A1)) is not particularly limited, and any urethane prepolymer used in the adhesive technology field can be used. Generally, a urethane prepolymer obtained by reacting an isocyanate composition (i) and a polyol composition (ii) under conditions in which the isocyanate groups contained in the isocyanate group (i) are in excess of the active hydrogen groups contained in the polyol composition (ii) is used.

[0090] (Isocyanate composition (i)) The above isocyanate composition (i) contains an isocyanate compound. The isocyanate compound is not particularly limited, and any compound that can be commonly used in the synthesis of urethane prepolymers can be used as appropriate. Examples include aromatic diisocyanates, aromatic aliphatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and burettes, nurates, adducts, allophanates, carbodiimide modified compounds, uretdione modified compounds of these diisocyanates, and urethane prepolymers obtained by reacting these polyisocyanates with polyols. These can be used individually or in combination.

[0091] Examples of the above aromatic diisocyanates include, but are not limited to, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate (also called polymeric MDI or crude MDI), 1,3-phenylenediisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylenediisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and 4,4',4"-triphenylmethane triisocyanate.

[0092] Aromatic aliphatic diisocyanates refer to aliphatic isocyanates having one or more aromatic rings in their molecule, and include, but are not limited to, m- or p-xylylene diisocyanate (also known as XDI) and α,α,α',α'-tetramethylxylylene diisocyanate (also known as TMXDI).

[0093] Examples of the above-mentioned aliphatic diisocyanates include, but are not limited to, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (also known as HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0094] Examples of the above-mentioned alicyclic diisocyanates include, but are not limited to, 3-isocyanate-methyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone diisocyanate (also known as IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 1,4-bis(isocyanate-methyl)cyclohexane.

[0095] (Polyol composition (ii)) The polyol composition (ii) used in the synthesis of urethane prepolymers comprises a polyol compound. The polyol compound is not particularly limited, and any compound commonly used in the synthesis of urethane prepolymers can be used as appropriate. For example, glycols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol;

[0096] Trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, and pentaerythritol; Bisphenols such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F; dimer ols; Polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene in the presence of polymerization initiators such as the above-mentioned glycol and trifunctional or tetrafunctional aliphatic alcohols; Polyether urethane polyols are polyether polyols whose molecular weight has been further increased with isocyanate compounds.

[0097] Polyester polyols (1) are reaction products of polyesters obtained by the ring-opening polymerization reaction of cyclic ester compounds such as propiolactone, butyrolactone, ε-caprolactone, σ-valerolactone, and β-methyl-σ-valerolactone with polyhydric alcohols such as the above-mentioned glycol, glycerin, trimethylolpropane, and pentaerythritol. Polyester polyols obtained by reacting the above-mentioned glycol, dimer ol, or bifunctional polyol such as the above-mentioned bisphenol with a polycarboxylic acid (2): Polyester polyols obtained by reacting a trifunctional or tetrafunctional aliphatic alcohol with a polycarboxylic acid (3); Polyester polyols obtained by reacting a bifunctional polyol with the above-mentioned trifunctional or tetrafunctional aliphatic alcohol and a polycarboxylic acid (4); Polyester polyols (5), which are polymers of hydroxyl acids such as dimethylolpropionic acid and castor oil fatty acids;

[0098] A polyester polyether polyurethane polyol obtained by reacting at least one of polyester polyols (1) to (5) with a polyether polyol and an isocyanate compound; Polyester polyurethane polyols obtained by increasing the molecular weight of polyester polyols (1) to (5) with isocyanate compounds; Examples include castor oil, dehydrated castor oil, hydrogenated castor oil (a hydrogenated form of castor oil), castor oil-based polyols such as 5-50 mole alkylene oxide adducts of castor oil, and mixtures thereof.

[0099] The polycarboxylic acids used in the synthesis of the above polyester polyols (2) to (4) include aromatic polybasic acids such as orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid anhydride, naphthalic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic dianhydride, 5-sodium sulfoisophthalic acid, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride; Methyl esters of aromatic polybasic acids such as dimethyl terephthalic acid and dimethyl 2,6-naphthalenedicarboxylate;

[0100] Aliphatic polybasic acids such as malonic acid, succinic acid, succinic anhydride, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, maleic anhydride, and itaconic acid; Alkyl esters of aliphatic polybasic acids such as dimethyl malonate, diethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, diethyl pimephosphate, diethyl sebacate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, and diethyl maleate;

[0101] Examples include 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, hymic anhydride, hettic anhydride, and other alicyclic polybasic acids; and these can be used individually or in combination of two or more.

[0102] The isocyanate compound used in the synthesis of polyurethane polyols can be the same as that exemplified in isocyanate composition (i).

[0103] The above polyol compound preferably contains at least one of a polyether polyol, a polyester polyol, or a polyester polyurethane polyol.

[0104] When introducing urea derivatives and biuret derivatives into a urethane prepolymer by using an amine compound in the polyol composition (ii), it is preferable that the amine compound used includes a primary or secondary monoamine compound.

[0105] Examples of the above primary monoamine compounds include methylamine, ethylamine, propylamine, isopropylamine, butylamine, amylamine, hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine (laurylamine), toridodecylamine, tetradecylamine (myristylamine), pentadecylamine, cetylamine, stearylamine, oleylamine, cocoalkylamine, beef tallow alkylamine, hydrogenated beef tallow alkylamine, allylamine, and other aliphatic unsaturated primary amines, as well as aniline and benzylamine.

[0106] Examples of the above secondary monoamine compounds include aliphatic unsaturated secondary amines such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diamylamine, diallylamine, methylaniline, ethylaniline, dibenzylamine, diphenylamine, dicocoalkylamine, dihydrogenated beef tallow alkylamine, and distearylamine.

[0107] The amount of the above monoamine compound is preferably 40% by mass or less of the total amount of the polyol composition (ii).

[0108] The above urethane prepolymer (A1) is obtained by reacting an isocyanate composition (i) and a polyol composition (ii) under conditions in which the isocyanate groups in isocyanate group (i) are in excess of the active hydrogen groups in polyol composition (ii). The equivalent ratio of isocyanate groups to active hydrogen groups in polyol composition (ii) [NCO] / [active hydrogen groups] can be adjusted as appropriate depending on the purpose, but as an example, it is between 2.0 and 20.0.

[0109] (Isocyanate compound (A2)) The above isocyanate compound (hereinafter sometimes referred to as isocyanate compound (A2)) can be an isocyanate compound that can be commonly used in the synthesis of the urethane prepolymer of the above isocyanate composition (i). Alternatively, the above isocyanate compound may be a biuret, uretdione, nurate, adduct, allophanate, or carbodiimide modified form. Specifically, examples include the biuret, nurate, and allophanate forms of hexamethylene diisocyanate, the nurate form of isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate and / or 2,4'-diphenylmethane diisocyanate, and their biuret, nurate, adduct, allophanate, carbodiimide modified form, allophanate, polymeric diphenylmethane diisocyanate, and adduct forms of toluene diisocyanate and trimethylolpropane.

[0110] (viscosity) When the above polyisocyanate composition (X) is used as a solvent-free, two-component curing adhesive, the viscosity of the polyisocyanate composition (X) is adjusted to a range suitable for the non-solvent laminating method. For example, the viscosity at 25°C is adjusted to be in the range of 1,000 to 10,000 mPas, more preferably 1,000 to 5,000 mPas. The viscosity of the polyisocyanate composition (X) can be adjusted, for example, by the amount of urethane prepolymer or isocyanate compound added.

[0111] (Polyol composition (Y)) The above polyol composition (Y) contains a polyol compound having multiple hydroxyl groups. There are no particular limitations on the polyol compound; any polyol compound commonly used in urethane-reactive two-component curing adhesives can be used. Specifically, examples include polyether polyols, polyester polyols, polyester polyether polyols, polyurethane polyols, polyester polyurethane polyols, polyether polyurethane polyols, polyester amide polyols, vegetable oil polyols, sugar alcohols, polycarbonate polyols, acrylic polyols, hydroxyl group-containing olefin resins, hydroxyl group-containing fluororesins, (poly)alkanolamines, and the like.

[0112] Examples of the above-mentioned polyether polyols include glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and triethylene glycol; and alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene, obtained by addition polymerization in the presence of polymerization initiators such as trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol, and triols of polypropylene glycol. Polypropylene glycol is preferred.

[0113] The above-mentioned polyester polyols are reaction products of a polyhydric alcohol and a polyhydric carboxylic acid. The polyhydric alcohol used in the synthesis of polyester polyols may be a diol or a polyol with three or more functionalities. Alternatively, polyester polyether polyols using the above-mentioned polyether polyol as the diol, or polyester polyurethane polyols using the polyurethane polyol described later, may also be used. Examples of such diols include aliphatic diols such as ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, 2,2-dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis(hydroxymethyl)cyclohesane, and 2,2,4-trimethyl-1,3-pentanediol;

[0114] Ether glycols such as polyoxyethylene glycol and polyoxypropylene glycol; Modified polyetherdiols obtained by ring-opening polymerization of aliphatic diols with various cyclic ether-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether;

[0115] Lactone-based polyester polyols obtained by polycondensation reactions of aliphatic diols with various lactones such as lactanoides and ε-caprolactone;

[0116] Bisphenols such as bisphenol A and bisphenol F;

[0117] Examples include alkylene oxide adducts of bisphenols obtained by adding ethylene oxide, propylene oxide, etc., to bisphenols such as bisphenol A and bisphenol F.

[0118] The above polyols with three or more functionalities include aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, and pentaerythritol;

[0119] Modified polyether polyols obtained by ring-opening polymerization of aliphatic polyols with various cyclic ether-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether;

[0120] Examples include lactone-based polyester polyols obtained by polycondensation reactions between aliphatic polyols and various lactones such as ε-caprolactone.

[0121] Examples of polycarboxylic acids used in the synthesis of the above-mentioned polyester polyols include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid; anhydrides or ester-forming derivatives of these aliphatic or dicarboxylic acids; and polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and ester-forming derivatives of these dihydroxycarboxylic acids, and dimer acids.

[0122] The polyurethane polyol described above is a reaction product of a low molecular weight or high molecular weight polyol and a polyisocyanate compound. As the low molecular weight polyol, the same polyhydric alcohols exemplified as raw materials for polyester polyols can be used. Examples of high molecular weight polyols include polyether polyols and polyester polyols. As the polyisocyanate compound, the same polyisocyanate used in the urethane prepolymer (A1) described above can be used.

[0123] Examples of the above-mentioned vegetable oil polyols include castor oil, dehydrated castor oil, hydrogenated castor oil (a hydrogenated product of castor oil), and castor oil alkylene oxide adducts of 5 to 50 moles.

[0124] Examples of the above sugar alcohols include pentaerythritol, sucrose, xylitol, sorbitol, isomalt, lactitol, maltitol, and mannitol sugar.

[0125] When the above two-component curing adhesive is used as a solvent-free type, the viscosity of the polyol composition (Y) is adjusted to a range suitable for the non-solvent laminating method. For example, the viscosity at 40°C is adjusted to be in the range of 100 to 5000 mPas, more preferably 100 to 3000 mPas. The viscosity of the polyol composition (Y) can be adjusted by the polyol compound's backbone and plasticizers, as described later. When adjusting the viscosity using a polyol compound skeleton, for example, the viscosity can be reduced by using polypropylene glycol or polyester polyols obtained by the reaction of aliphatic carboxylic acids with polyols. Alternatively, viscosity can be increased by using a polyester polyol obtained by the reaction of an aromatic carboxylic acid with a polyol.

[0126] When using the above-mentioned two-component curing adhesive, it is preferable to use a composition in which one or both of the polyisocyanate composition (X) and polyol composition (Y) contain a polyester skeleton, as this can yield a packaging material with superior retort resistance.

[0127] (Other components of the adhesive) The above-mentioned two-component curing adhesive may contain components other than those listed above. Other components may be included in either or both of the polyisocyanate composition (X) and the polyol composition (Y), or they may be prepared separately and mixed with the polyisocyanate composition (X) and the polyol composition (Y) immediately before application of the adhesive. The following describes each component.

[0128] (Polyamine(C)) The above polyol composition (Y) may contain a polyamine (C) having multiple amino groups. In this specification, an amino group refers to an NH2 group or an NHR group (where R is an alkyl group or aryl group which may have a functional group).

[0129] The above polyamine (C) can be any known polyamine without particular limitation, including methylenediamine, ethylenediamine, isophoronediamine, 3,9-dipropanamine-2,4,8,10-tetraoxaspirodoundecane, lysine, 2,2,4-trimethylhexamethylenediamine, hydrazine, piperazine, 2-hydroxyethylethylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, poly(propylene glycol)diamine, poly(propylene glycol)triamine, poly(propylene glycol)tetraamine, 1,2-diaminopropane, 1,3-diaminopropane,

[0130] 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripylenetetramine, tetraethylenepentamine, tetrapropylenepentamine, pentaethylenehexamine, nonaethylenedecamine, trimethylhexamethylenediamine, tetra(aminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, 1,3-bis(2'-aminoethylamino)propane, triethylene-bis(trimethylene)hexamine, bis(3-aminoethyl)amine, bishexamethylenetriamine, 1,4-cyclohexanediamine, 4,4'-methylenebiscyclohexylamine, 4,4'-isopropylidenebiscyclohexylamine, norbornadiamine,

[0131] Amine compounds (C1) having multiple amino groups, such as bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane, isophoronediamine, mensendiamine, bis(cyanoethyl)diethylenetriamine, 1,4-bis-(8-aminopropyl)-piperazine, piperazine-1,4-diazacycloheptane, 1-(2'-aminoethylpiperazine), 1-[2'-(2"-aminoethylamino)ethyl]piperazine, tricyclodecanediamine, and polyureamines which are reaction products of the above-mentioned polyamines and the above-mentioned isocyanate components.

[0132] Primary or secondary alkanolamines (C2) such as monoethanolamine, monoisopropanolamine, monobutanolamine, N-methylethanolamine, N-ethylethanolamine, N-methylpropanolamine, diethanolamine, and diisopropanolamine.

[0133] Examples include primary or secondary amines (C3) such as ethylamine, octylamine, laurylamine, myristylamine, stearylamine, oleylamine, diethylamine, dibutylamine, and distearylamine.

[0134] The amount of polyamine (C) is preferably blended such that the amine value of the polyol composition (Y) is 20 to 70 mgKOH / g, more preferably 25 to 50 mgKOH / g.

[0135] In this specification, the amine value refers to the number of milligrams of KOH equivalent to the amount of HCl required to neutralize 1 g of the sample. There are no particular restrictions, and it can be calculated using known methods. If the chemical structure of amine compound (C) and, if necessary, the average molecular weight are known, the molecular weight can be calculated using the formula: (number of amino groups per molecule / average molecular weight) × 56.1 × 1000. If the chemical structure or average molecular weight of an amine compound is unknown, it can be measured according to a known method for determining the amine value, for example, JIS K7237-1995.

[0136] (Monool compound (D)) The above polyol composition (Y) may also contain a monool compound (D) having one alcoholic hydroxyl group. The main chain of the monool compound (D) is not particularly limited and can be any vinyl resin, acrylic resin, polyester, epoxy resin, urethane resin, etc., having one hydroxyl group. In addition, aliphatic alcohols, alkylalkylene glycols, and the like can also be used. The main chain of the monool compound (D) may be linear or branched. There are no particular limitations on the bonding position of the hydroxyl group, but it is preferable that it be located at the end of the molecular chain.

[0137] Specific examples of the above monool compound (D) include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, lauryl alcohol, myristyl alcohol, pentadecanol, cetyl alcohol, heptadecanol, stearyl alcohol, nonadecanol, other alkanols (C20-C50), oleyl alcohol, and aliphatic monools such as their isomers.

[0138] Cyclohexanol, methylcyclohexanol, 4-butylcyclohexanol, 4-pentylcyclohexanol, 4-hexylcyclohexanol, cyclodecanol, cyclododecanol, cyclopentadecanol, 4-isopropylcyclohexanol, 3,5,5-trimethylcyclohexanol, menthol, 2-norbornanol, borneol, 2-adamantanol, dicyclohexylmethanol, decatol, 2-cyclohexylcyclohexanol, 4-cyclohexylcyclohexanol, 4-(4-propylcyclohexyl)cyclohexanol, 4-(4-pentylcyclohexanol) (Xyl)cyclohexanol, α-ambrinol, deoxycorticosterone, 11-dehydrocorticosterone, cholesterol, β-sitosterol, campesterol, stigmasterol, brassicasterol, lanosterol, ergosterol, β-cholestanol, testosterone, estrone, digitoxygenin, dehydroepiandrosterone, coprostanol, pregnenolone, epicholestanol, 7-dehydrocholesterol, estradiol benzoate, tigogenin, hecogenin, methandienone, cortisone acetate, stenolone, and alicyclic monools such as their isomers.

[0139] Aromatic aliphatic monools such as benzyl alcohol,

[0140] Examples include polyoxyalkylene monools obtained by ring-opening addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran, using an alkyl compound containing one active hydrogen atom as an initiator.

[0141] (catalyst) Examples of catalysts include metal catalysts, amine catalysts, and aliphatic cyclic amide compounds.

[0142] Examples of the above-mentioned metal-based catalysts include metal complex-based, inorganic metal-based, and organometallic-based catalysts. Examples of metal complex catalysts include acetylacetonate salts of metals selected from the group consisting of Fe (iron), Mn (manganese), Cu (copper), Zr (zirconium), Th (thorium), Ti (titanium), Al (aluminum), and Co (cobalt), such as iron acetylacetonate, manganese acetylacetonate, copper acetylacetonate, and zirconia acetylacetonate.

[0143] Examples of the inorganic metal catalysts mentioned above include those selected from Sn, Fe, Mn, Cu, Zr, Th, Ti, Al, Co, etc.

[0144] Examples of the above organometallic catalysts include organozinc compounds such as zinc octoate, zinc neodecanoate, and zinc naphthenate; organotin compounds such as stanus diacetate, stanus dioctoate, stanus dioleate, stanus dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin oxide, and dibutyltin dichloride; organonickel compounds such as nickel octoate and nickel naphthenate; organocaltyl compounds such as cobalt octoate and cobalt naphthenate; organobismuth compounds such as bismuth octoate, bismuth neodecanoate, and bismuth naphthenate; tetraisopropyloxytitanate, dibutyltitanium dichloride, tetrabutyltitanium trichloride, butoxytitanium trichloride; aliphatic diketones; aromatic diketones; and titanium compounds such as titanium chelate complexes with at least one alcohol having 2 to 10 carbon atoms as a ligand.

[0145] The above amine-based catalysts include triethylenediamine, 2-methyltriethylenediamine, quinuclidine, 2-methylquinuclidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N',N",N"-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N',N",N"-pentamethyldipropylenetriamine, N,N,N',N'-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl) ether, dimethylethanolamine, dimethylisopropanolamine, dimethylaminoethoxyethanol, N,N-dimethyl-N'-(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N'-(2-hydroxyethyl)propanediamine, bis(dimethylaminopropyl)amine, bis(dimethylaminopropyl)iso Propanolamine, 3-Quinuclidinol, N,N,N',N'-Tetramethylguanidine, 1,3,5-Tris(N,N-dimethylaminopropyl)hexahydro-S-triazine, 1,8-Diazabicyclo[5.4.0]undecene-7, N-Methyl-N'-(2-dimethylaminoethyl)piperazine, N,N'-Dimethylpiperazine, Dimethylcyclohexylamine, N-Methylmorpholine, N-Ethylmorpholine, 1-Methylimidazole, 1 Examples include 2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropylimidazole, N,N-dimethylhexanolamine, N-methyl-N'-(2-hydroxyethyl)piperazine, 1-(2-hydroxyethyl)imidazole, 1-(2-hydroxypropyl)imidazole, 1-(2-hydroxyethyl)-2-methylimidazole, and 1-(2-hydroxypropyl)-2-methylimidazole.

[0146] Examples of the above-mentioned aliphatic cyclic amide compounds include δ-valerolactam, ε-caprolactam, ω-enanthollactam, η-capryllactam, and β-propiolactam. Among these, ε-caprolactam is most effective in accelerating hardening.

[0147] (acid anhydride) Examples of acid anhydrides include cyclic aliphatic acid anhydrides, aromatic acid anhydrides, and unsaturated carboxylic acid anhydrides, and one or more types can be used in combination. More specifically, for example, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, dodecenyl succinic anhydride, polyadipic anhydride, polyazelaic anhydride, polysebacic anhydride, poly(ethyloctadecanediic acid) anhydride, poly(phenylhexadecanedioic acid) anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylhymic anhydride, trialkyltetrahydrophthalic anhydride, Examples include methylcyclohexenedicarboxylic acid anhydride, methylcyclohexenetetracarboxylic acid anhydride, ethylene glycol bistrimellitate dianhydride, hetic acid anhydride, nadic acid anhydride, methylnadic acid anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexane-1,2-dicarboxylic acid anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dianhydride, and 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dianhydride.

[0148] Alternatively, the above-mentioned compounds modified with glycol may be used as acid anhydrides. Examples of glycols that can be used for modification include alkylene glycols such as ethylene glycol, propylene glycol, and neopentyl glycol; and polyether glycols such as polyethylene glycol, polypropylene glycol, and butyltetramethylene ether glycol. Furthermore, copolymer polyether glycols of two or more of these glycols and / or polyether glycols can also be used.

[0149] (Coupling agent) Examples of coupling agents include silane coupling agents, titanate-based coupling agents, and aluminum-based coupling agents.

[0150] Examples of silane coupling agents include aminosilanes such as γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; epoxysilanes such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyltriethoxysilane; vinylsilanes such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane; and hexamethyldisilazane and γ-mercaptopropyltrimethoxysilane.

[0151] Examples of titanate-based coupling agents include tetraisopropoxytitanium, tetra-n-butoxytitanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, titanium lactate, and tetrastearoxititanium.

[0152] Examples of aluminum-based coupling agents include acetalkoxyaluminum diisopropylate.

[0153] (Pigment) There are no particular restrictions on the pigments used, and examples include organic and inorganic pigments such as extender pigments, white pigments, black pigments, gray pigments, red pigments, brown pigments, green pigments, blue pigments, metal powder pigments, luminescent pigments, pearlescent pigments, and even plastic pigments, as listed in the 1970 edition of the Paint Raw Materials Handbook (compiled by the Japan Paint Manufacturers Association).

[0154] Examples of the above-mentioned extender pigments include precipitated barium sulfate, granite powder, precipitated calcium carbonate, calcium bicarbonate, limestone, alumina white, silica, hydrated fine silica (white carbon), ultrafine anhydrous silica (aerosil), silica sand, talc, precipitated magnesium carbonate, bentonite, clay, kaolin, and yellow ochre.

[0155] Specific examples of the above organic pigments include various insoluble azo pigments such as Benzidine Yellow, Hansa Yellow, and Laked 4R; soluble azo pigments such as Laked C, Carmine 6B, and Bordeaux 10; various (copper) phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; various chlorinated dye lakes such as rhodamine lake and methyl violet lake; various mordant dyes such as quinoline lake and fast sky blue; various vat dyes such as anthraquinone pigments, thioindigo pigments, and perinone pigments; various quinacridone pigments such as Syncasia Red B; various dioxazine pigments such as dioxazine violet; various condensed azo pigments such as chromophthal; and aniline black.

[0156] Examples of the inorganic pigments mentioned above include various chromates such as lead yellow, zinc chromate, and molybdate orange; various ferrocyanide compounds such as Prussian blue; various metal oxides such as titanium dioxide, zinc oxide, mapo yellow, iron oxide, red iron oxide, chrome green oxide, and zirconium oxide; various sulfides or selenides such as cadmium yellow, cadmium red, and mercury sulfide; various sulfates such as barium sulfate and lead sulfate; various silicates such as calcium silicate and ultramarine; various carbonates such as calcium carbonate and magnesium carbonate; various phosphates such as cobalt violet and manganese purple; various metal powder pigments such as aluminum powder, gold powder, silver powder, copper powder, bronze powder, and brass powder; metal flake pigments and mica flake pigments; metallic pigments and pearl pigments such as mica flake pigments coated with metal oxides and mica-like iron oxide pigments; graphite, carbon black, and the like.

[0157] Examples of the above-mentioned plastic pigments include "Grandeur PP-1000" and "PP-2000S" manufactured by DIC Corporation.

[0158] The pigments used can be selected appropriately depending on the purpose, but for example, inorganic oxides such as titanium dioxide and zinc oxide are preferred as white pigments because they have excellent durability, weather resistance, and design properties, and carbon black is preferred as a black pigment.

[0159] The amount of the above-mentioned pigment is, for example, 1 to 400 parts by mass per 100 parts by mass of the total non-volatile content of the polyol composition (X) and the polyisocyanate composition (Y), and it is more preferable to use 10 to 300 parts by mass to improve adhesion and blocking resistance.

[0160] (Plasticizer) Examples of plasticizers include phthalate-based plasticizers, fatty acid-based plasticizers, aromatic polycarboxylic acid-based plasticizers, phosphate-based plasticizers, polyol-based plasticizers, epoxy-based plasticizers, polyester-based plasticizers, and carbonate-based plasticizers.

[0161] Examples of the phthalate-based plasticizers mentioned above include phthalate ester plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, diheptyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, didecyl phthalate, diisodecyl phthalate, ditridecyl phthalate, diundecyl phthalate, dilauryl phthalate, distearyl phthalate, diphenyl phthalate, dibenzyl phthalate, butylbenzyl phthalate, dicyclohexyl phthalate, octyldecyl phthalate, dimethyl isophthalate, di-(2-ethylhexyl) isophthalate, and diisooctyl isophthalate, as well as tetrahydrophthalate plasticizers such as di-(2-ethylhexyl)tetrahydrophthalate, di-n-octyltetrahydrophthalate, and diisodecyltetrahydrophthalate.

[0162] Examples of the above fatty acid-based plasticizers include adipic acid-based plasticizers such as di-n-butyl adipate, di-(2-ethylhexyl) adipate, diisodecyl adipate, diisononyl adipate, di(C6-C10 alkyl) adipate, and dibutyldiglycol adipate; azelaic acid-based plasticizers such as di-n-hexyl azelate, di-(2-ethylhexyl) azelate, and diisooctyl azelate; and di-n-butyl sebacate, di Sebacate-based plasticizers such as -(2-ethylhexyl) sebacate and diisononyl sebacate; maleic acid-based plasticizers such as dimethyl maleate, diethyl maleate, di-n-butyl maleate, and di-(2-ethylhexyl) maleate; fumaric acid-based plasticizers such as di-n-butyl fumarate and di-(2-ethylhexyl) fumarate; monomethyl itaconate, monobutyl itaconate, dimethyl itaconate, diethyl itaconate, di Examples of plasticizers include itaconic acid-based plasticizers such as butyl itaconate and di-(2-ethylhexyl)itaconate; stearic acid-based plasticizers such as n-butyl stearate, glycerin monostearate, and diethylene glycol distearate; oleic acid-based plasticizers such as butyl oleate, glyceryl monooleate, and diethylene glycol monooleate; citrate-based plasticizers such as triethyl citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, and acetyl tri-(2-ethylhexyl) citrate; ricinoleic acid-based plasticizers such as methylacetyl ricinoleate, butylacetyl ricinoleate, glyceryl monoricinoleate, and diethylene glycol monoricinoleate; and other fatty acid-based plasticizers such as diethylene glycol monolaurate, diethylene glycol diperargonate, and pentaerythritol fatty acid esters.

[0163] Examples of the above aromatic polycarboxylic acid-based plasticizers include trimellitic acid-based plasticizers such as tri-n-hexyl trimellitate, tri-(2-ethylhexyl) trimellitate, tri-n-octyl trimellitate, triisooctyl trimellitate, triisononyl trimellitate, tridecyl trimellitate, and triisodecyl trimellitate, as well as pyromellitic acid-based plasticizers such as tetra-(2-ethylhexyl) pyromelitate and tetra-n-octyl pyromelitate.

[0164] Examples of the above-mentioned phosphate-based plasticizers include triethyl phosphate, tributyl phosphate, tri-(2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyldiphenyl phosphate, cresyldiphenyl phosphate, cresylphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(chloroethyl) phosphate, tris(chloropropyl) phosphate, tris(dichloropropyl) phosphate, and tris(isopropylphenyl) phosphate.

[0165] Examples of the polyol-based plasticizers mentioned above include glycol-based plasticizers such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, triethylene glycol di-(2-ethyl butyrate), triethylene glycol di-(2-ethylhexoate), and dibutylmethylene bisthioglycolate, as well as glycerin-based plasticizers such as glycerol monoacetate, glycerol triacetate, and glycerol tributyrate.

[0166] Examples of the epoxy plasticizers mentioned above include epoxidized soybean oil, epoxybutyl stearate, di-2-ethylhexyl epoxyhexahydrophthalate, diisodecyl epoxyhexahydrophthalate, epoxy triglycerides, octyl epoxidized oleate, and decyl epoxidized oleate.

[0167] Examples of the above-mentioned polyester plasticizers include adipic acid-based polyesters, sebaciate-based polyesters, and phthalate-based polyesters.

[0168] Examples of the carbonate-based plasticizers mentioned above include propylene carbonate and ethylene carbonate.

[0169] Other examples of plasticizers include partially hydrogenated terphenyl, adhesive plasticizers, diallyl phthalate, and polymerizable plasticizers such as acrylic monomers and oligomers. These plasticizers can be used individually or in combination of two or more.

[0170] (Phosphate compounds) Examples of phosphate compounds (C6) include phosphoric acid, pyrophosphate, triphosphate, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, dibutyl phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, isododecyl acid phosphate, butoxyethyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, 2-hydroxyethyl methacrylate acid phosphate, and polyoxyethylene alkyl ether phosphate.

[0171] (Form of adhesive) The above-mentioned two-component curing adhesive may be in either a solvent-based or solvent-free form. In this specification, "solvent-type" adhesive refers to a form used in the so-called dry lamination method, in which the adhesive is applied to a substrate, heated in an oven or the like to evaporate the organic solvent in the coating, and then bonded to another substrate. Either the polyisocyanate composition (X) or the polyol composition (Y), or both, contain an organic solvent capable of dissolving (diluting) the components of the polyisocyanate composition (X) or the polyol composition (Y).

[0172] Examples of the above-mentioned organic solvents include esters such as ethyl acetate, butyl acetate, and cellosolve acetate; ketones such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and dioxane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; dimethyl sulfoxide and dimethyl sulfamide. The organic solvents used as reaction media during the production of the components of the polyisocyanate composition (X) and polyol composition (Y) may also be used as diluents during painting.

[0173] In this specification, "solvent-free" adhesive refers to an adhesive used in a method of bonding with another substrate without a step of heating in an oven or the like to volatilize the solvent after coating the substrate with the adhesive, in the so-called non-solvent laminating method. The polyisocyanate composition (X) and polyol composition (Y) substantially do not contain esters such as ethyl acetate, butyl acetate, and cellosolve acetate, ketones such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone, ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, and highly soluble organic solvents such as dimethyl sulfoxide and dimethyl sulfamide, particularly ethyl acetate or methyl ethyl ketone. If trace amounts of organic solvent remain in the polyisocyanate composition (X) or polyol composition (Y) due to incomplete removal of the components of the polyisocyanate composition (X) or polyol composition (Y) or the organic solvent used as a reaction medium during the production of the raw materials, then the composition is considered to be substantially free of organic solvent. Furthermore, if the polyol composition (Y) contains a low molecular weight alcohol, the low molecular weight alcohol reacts with the polyisocyanate composition (X) and becomes part of the coating film, so it does not need to be volatilized after coating. Therefore, this form is also treated as a solvent-free adhesive, and low molecular weight alcohols are not considered organic solvents.

[0174] The above two-component curing adhesive is preferably used in a mixture such that the ratio [NCO] / [OH] of the number of moles of isocyanate groups [NCO] contained in the polyisocyanate composition (X) to the number of moles of hydroxyl groups [OH] contained in the polyol composition (Y) is 1.0 to 3.0. This makes it possible to obtain appropriate curing properties regardless of the ambient humidity during coating.

[0175] The above two-component curing adhesives can also be commercially available products, such as DIC Graphics Co., Ltd.'s DIC Dry LX-500 / KW-75, DIC Dry LX-520 / KO40, DIC Dry LX-703VL / KR-90, DIC Dry LX-732 / KVM-90, DIC Dry LX-906 / KO55, DIC Dry LX-963 / KO-40, DIC Dry LX-901 / KW-75, etc., and Toyo Ink Co., Ltd.'s TM-250HV / CAT-RT86, TM-595 / CAT-56, TM-265L / CAT-RT37, AD-502 / CAT-10, AD-556 / CAT-56, AD-811 / CAT-RT8, AD-817 / CAT-RT56, AD-900 / CA T-RT85 and other products manufactured by Mitsui Chemicals, Inc., including Takelac A-310 / Takenate A-3, Takelac A-315 / Takenate A-10, Takelac A-385 / Takenate A-50, Takelac A-515 / Takenate A-50, Takelac A-520 / Takenate A-50, Takelac A-525 / Takenate A-52, Takelac A-606 / Takenate Examples include Takelac A-10, Takelac A-620 / Takenate A-65, Takelac A-626 / Takenate A-50, Takelac A-627 / Takenate A-65, Takelac A-975 / Takenate A-3, etc., and Seikabond E-366 / C-83, E-370 / C-84, E-372 / C-76, A601 / C84, etc., manufactured by Dainichi Seika Kogyo Co., Ltd. Examples of polyether-based adhesive / curing agent combinations include DIC Dry LX-401A / SP-60, DIC Dry LE-3100 / SL-75, etc., manufactured by DIC Graphics Co., Ltd., and Seikabond A-159 / C-89F, etc., manufactured by Dainichi Seika Kogyo Co., Ltd. Other examples of polyurethane adhesives include one-component moisture-curing polyurethane resins (product name: Unoflex series) and two-component curing polyurethane resins (product name: Polybond series) manufactured by Sanyo Chemical Industries, Ltd.

[0176] (Biomass adhesive) In the above-mentioned two-component curing adhesive, it is preferable to use plant-derived raw materials as raw materials for the polyisocyanate composition (X) or polyol composition (Y), taking into consideration the construction of a sustainable circular society that should develop sustainably.

[0177] Furthermore, the biomass content can be increased by appropriately using biomass raw materials as raw materials for the above-mentioned two-component curing adhesive. Examples of biomass raw materials include castor oil-based polyols such as castor oil, dehydrated castor oil, hydrogenated castor oil (a hydrogenated form of castor oil), and 5-50 molar alkylene oxide adducts of castor oil, as well as aliphatic polybasic acids such as succinic acid, succinic anhydride, glutaric acid, adipic acid, azelaic acid, sebacic acid, and itaconic acid, and alkyl esters and dimer acids of these acids.

[0178] Commercially available biomass adhesives can also be used. Commercially available adhesives listed by the Japan Organic Resources Association can be used, such as DIC Dry BM (manufactured by DIC Corporation) and Takenate BM (manufactured by Mitsui Chemicals, Inc.).

[0179] The weight of the above adhesive layer after drying is 0.1 to 10 g / m². 2 Preferably, it is 1-6 g / m 2 It is more preferable that the amount be 2-5 g / m 2 It is even more preferable that this be the case.

[0180] The thickness of the adhesive layer is preferably 0.1 to 10 μm, more preferably 1 to 7 μm, and even more preferably 2 to 5 μm.

[0181] In the above-mentioned adhesive, a functional adhesive may be used. For example, as an adhesive with gas barrier properties, you can use the PASLIM series of oxygen barrier adhesives manufactured by DIC Corporation, which is a two-component curing adhesive made of polyester polyol and isocyanate compound. After the gas barrier adhesive hardens or dries, it forms a gas barrier adhesive layer. Using a gas barrier adhesive is preferable because it can further enhance the gas barrier properties of the laminate of the present invention.

[0182] Furthermore, various adhesives can be used as the adhesive mentioned above, and it is preferable to use a pressure-sensitive adhesive. Examples of pressure-sensitive adhesives include rubber-based adhesives obtained by dissolving polyisobutylene rubber, butyl rubber, or mixtures thereof in organic solvents such as benzene, toluene, xylene, and hexane; or rubber-based adhesives obtained by compounding these rubber-based adhesives with tackifiers such as abiethylene rosin ester, terpene-phenol copolymer, and terpene-indene copolymer; or acrylic-based adhesives obtained by dissolving acrylic copolymers with a glass transition temperature of -20°C or lower, such as 2-ethylhexyl acrylate-n-butyl acrylate copolymer and 2-ethylhexyl acrylate-ethyl acrylate-methyl methacrylate copolymer, in organic solvents.

[0183] The above adhesive can be applied by methods such as direct gravure roll coating, gravure offset roll coating, kiss coating, reverse roll coating, fontein method, transfer roll coating, or other methods.

[0184] If the adhesive is solvent-based, the adhesive can be applied to one substrate using a roll such as a gravure roll, the organic solvent can be evaporated by heating in an oven or the like, and then the other substrate can be bonded to obtain the laminate of the present invention. It is preferable to perform an aging treatment after lamination. The preferred aging temperature is room temperature to 80°C, and the aging time is 12 to 240 hours.

[0185] If the adhesive is solvent-free, the adhesive, which has been preheated to approximately 40°C to 100°C, is applied to one substrate using a roll such as a gravure roll, and then the other substrate is immediately bonded to it to obtain the laminate of the present invention. It is preferable to perform an aging treatment after lamination. The preferred aging temperature is room temperature to 70°C, and the aging time is 6 to 240 hours.

[0186] The amount of adhesive applied should be adjusted as needed. For solvent-type products, one example is the amount of non-volatile components, which is 1 g / m². 2 More than 10g / m 2 Preferably 1 g / m 2 More than 5g / m 2 Adjust it so that it is as follows: For solvent-free types, the application amount of adhesive is, for example, 1 g / m². 2 More than 10g / m 2 Preferably 1 g / m 2 More than 5g / m 2 The following applies:

[0187] (thermoplastic resin) Furthermore, the adhesive layer can also be formed from a thermoplastic resin, and it can be formed by conventionally known methods, such as extrusion lamination or sand lamination. Examples of thermoplastic resins that can be used in the adhesive layer include ethylene-based resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE); propylene-based resins such as propylene homopolymers, propylene-α-olefin random copolymers, and propylene-α-olefin block copolymers; norbornene-based polymers such as ring-opening polymers (COP) of norbornene monomers and norbornene copolymers (COC) obtained by copolymerizing norbornene monomers with olefins such as ethylene, and their hydrogenated products; cyclic polyolefin resins such as vinyl alicyclic hydrocarbon polymers and cyclic conjugated diene polymers; and ethylene- Examples include polyethylene-based elastomers such as vinyl acetate copolymer (EVA) and ethylene-α-olefin copolymer, thermoplastic elastomers such as polypropylene-based elastomers and butene-based elastomers; ethylene-based copolymers such as ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); and further, ionomers of ethylene-acrylic acid copolymer and ionomers of ethylene-methacrylic acid copolymer. Furthermore, in order to improve the adhesion between layers, acid-modified polyolefin resins, which are obtained by modifying the above-mentioned polyolefin resin with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, or itaconic acid, can also be used. Furthermore, resins obtained by graft polymerization or copolymerization of polyolefin resins with unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, or ester monomers can also be used. These resins can be used individually or in combination of two or more types. Furthermore, it is also preferable to use an ethylene-based resin that uses biomass-derived ethylene as the monomer unit.

[0188] When laminating adhesive layers by extrusion lamination, an anchor coat layer may be provided on the surface of the layer being laminated, formed by applying an anchor coat agent and drying it. Examples of anchor coating agents include anchor coating agents made from any resin with a heat resistance temperature of 135°C or higher, such as polybutadiene resins, urethane resins, polyisocyanates / polyether polyols, polyethyleneimines, vinyl-modified resins, epoxy resins, polyester resins, alkyl titanates, etc., and anchor coating agents obtained by diluting the above adhesives with an organic solvent. In particular, polyethyleneimine-based anchor coating agents and anchor coating agents obtained by diluting the above adhesive with an organic solvent can be preferably used. Furthermore, a silane coupling agent may be used as an additive, and nitrated cotton may also be used to improve heat resistance.

[0189] When obtaining a laminate of the present invention by laminating the sealant film of the present invention with a substrate or the like using extrusion lamination or sand lamination, the nip roll or chill roll used during lamination may be replaced with an embossing roll to apply embossing to the surface on the seal layer side.

[0190] (Printing layer) The printed layer is a layer on which letters, figures, symbols, or other desired patterns are printed. There are no particular limitations on the printing method or ink; known printing methods and inks can be used. The films used as the substrates mentioned above are often printed using methods such as gravure printing, flexographic printing, offset lithography, and inkjet printing. In addition, printing inks are also used that combine these printing methods with methods that cure them using active energy rays such as ultraviolet (UV), LEDs, and electron beams (EB), or by heat. Furthermore, depending on the solvent used, inks may also be referred to as water-based inks or organic solvent-based inks.

[0191] Specifically, these include gravure printing inks and flexographic printing inks (in some industries, gravure printing inks and flexographic printing inks are referred to as liquid printing inks), UV-curable inks for lithographic offset printing, electron beam-curable inks for lithographic offset printing, UV-curable inks for inkjet recording printing, and electron beam-curable inks for inkjet recording printing.

[0192] The position in which the printed layer printed using these inks is provided is arbitrary; it may be provided on the above-mentioned substrate, or a separate substrate with a printed layer provided may be one of the components of the laminate of the present invention, and the position is arbitrary. Furthermore, the ink may contain resin, colorant, and solvent as essential components, or it may be a so-called clear ink that contains resin and solvent but substantially no colorant. The following describes liquid printing inks containing polyurethane resin and colorants, which are most commonly used for printing on laminate films.

[0193] (Liquid printing ink) The liquid printing ink printed on the printing layer of the present invention contains a polyurethane resin and a coloring agent. Furthermore, it is preferable that the liquid printing ink contains one or more polyurethane resins consisting of polyester polyol and polyisocyanate.

[0194] (Polyurethane resin) The above liquid printing ink contains a polyurethane resin obtained by polymerizing a polyol and a polyisocyanate. The polyol is preferably a polyester polyol. Furthermore, if necessary, polyurethane resins may be synthesized in combination with polyether polyols, polyester polyols, general-purpose polyols other than polyether polyols, chain extenders, and end-capping agents. Furthermore, the polyol may be reacted with a polyisocyanate to form a urethane prepolymer having isocyanate groups at its ends, and this prepolymer may be reacted with a polyamine compound to synthesize a polyurethane resin. Polyurethane resin may be used alone or in combination with other materials in liquid printing inks.

[0195] The glass transition temperature of the polyurethane resin described above is preferably -60°C or higher, and more preferably -50°C or higher. Furthermore, the temperature is preferably below 0°C, and more preferably below -30°C.

[0196] (Polyester polyol) The polyester polyol, which is a reaction raw material for the polyurethane resin used in the above liquid printing ink, is obtained by reacting a polycarboxylic acid having two or more carboxyl groups with a polyol having two or more hydroxyl groups.

[0197] (Polycarboxylic acid) Examples of the polycarboxylic acids mentioned above include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dimer acid, and their acid anhydrides, as well as dicarboxylic acids such as trimellitic acid and its anhydride, benzenetetracarboxylic acid, benzenepentacarboxylic acid, benzenehexacarboxylic acid, and anhydrides of these acids.

[0198] These polycarboxylic acids may be used individually or in combination of multiple types. For example, when polycarboxylic acids are used in combination, azelaic acid, pimelic acid, and malonic acid are used in combination with succinic acid, sebacic acid, suberic acid, and adipic acid, which is preferable because it results in good laminate strength and heat resistance. Furthermore, using succinic acid, succinic anhydride, and adipic acid in combination with sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, superiric acid, azelaic acid, trimellitic acid, and pyromellitic acid is preferable because it can achieve both adhesion to a wide variety of films, blocking resistance, and high lamination strength.

[0199] As the polycarboxylic acid mentioned above, plant-derived raw materials can also be used. Using plant-derived polycarboxylic acids is preferable because it can increase the biomass content of liquid printing inks. Specifically, examples include succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dimer acid, and malic acid.

[0200] (Polyol) Examples of the polyols mentioned above include glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-butynediol, 1,4-butylenediol, etc.; 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, 2-butanediol Branched glycols such as ethyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptanediol, and 2-methyl-1,8-octanediol can be used; glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol, 1,2,6-hexanetriol, 1,2,4-butanetriol, etc. can be used. These compounds may be used individually or in combination of two or more.

[0201] As the polyol mentioned above, plant-derived raw materials can also be used. Using plant-derived polyols is preferable because it allows for an increase in the biomass content of liquid printing inks. Specifically, examples include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, pentylene glycol, 1,10-dodecanediol, dimer diol, isosorbide, and the like.

[0202] The above polyester polyol is preferably contained in an amount of 30 to 95% by mass relative to the total amount of the polyurethane resin, more preferably 40 to 90% by mass, and most preferably 45 to 85% by mass.

[0203] The number average molecular weight of the above polyester polyol is preferably in the range of 400 to 10,000, more preferably in the range of 500 to 7,000, even more preferably in the range of 800 to 6,000, even more preferably in the range of 1,000 to 6,000, and even more preferably in the range of 1,500 to 5,500. In this invention, the number-average and weight-average molecular weights are those measured by gel permeation chromatography (GPC) under the following conditions.

[0204] (GPC measurement) Measurement device: High-speed GPC device (HLC-8220GPC manufactured by Tosoh Corporation) Columns: The following columns manufactured by Tosoh Corporation were used, connected in series. "TSKgelG5000" (7.8mmI.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mm I.D. x 30cm) x 1 Detector: RI (Differential Refractometer) Column temperature: 40°C; Eluent: Tetrahydrofuran (THF) Flow rate: 1.0 mL / min; Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass) Standard samples: Calibration curves were prepared using the following standard polystyrene samples.

[0205] [Standard polystyrene] TSKgel Standard Polystyrene A-500, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-1000, manufactured by Tosoh Corporation. "TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

[0206] (Polyether polyol) Furthermore, as a constituent component of the polyurethane resin, it is more preferable to contain polyether polyol in the range of 1 to 40% by mass with respect to the polyurethane resin. As the polyether polyol, various known polyether polyols generally used in the production of polyurethane resins can be used, and one kind or two or more kinds can be used in combination. For example, polyether polyols such as polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, etc. can be mentioned. If the polyether polyol is 1% by mass or more with respect to the polyurethane resin, the solubility of the polyurethane resin in ketone, ester, and alcohol solvents is also good, and the re-solubility of the ink film in these solvents is difficult to decrease, and the tone reproducibility of the printed matter is difficult to deteriorate. Also, if it is 40% by mass or less, the blocking resistance is difficult to decrease. Among them, it is still more preferable that the polyether polyol is contained in the range of 1 to 30% by mass with respect to the polyurethane resin, and most preferably in the range of 1 to 20% by mass.

[0207] Also, the number average molecular weight of the above polyether polyol is more preferably 100 to 4,000. If the number average molecular weight of the polyether polyol is 100 or more, the film of the polyurethane resin will not become hard and the adhesiveness to the polyester film will not easily decrease. If the number average molecular weight is 4,000 or less, the film of the polyurethane resin has sufficient strength and the blocking resistance of the ink film tends not to easily decrease.

[0208] Specific examples of the above polyether polyol include bifunctional alcohols (glycols) such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol; trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, pentaerythritol; bisphenols such as bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F;

[0209] Examples include polyether polyols such as polytetramethylene glycol, polypropylene glycol, polyethylene glycol, and polytrimethylene glycol, obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene in the presence of polymerization initiators such as the above-mentioned glycol and trifunctional or tetrafunctional aliphatic alcohols; and polyether urethane polyols, which are obtained by further increasing the molecular weight of the polyether polyol with the above-mentioned aromatic or aliphatic polyisocyanate.

[0210] (General-purpose polyol) In the synthesis of the polyurethane resin used in the above liquid printing ink, a general-purpose polyol may be used in combination as needed. As the general-purpose polyol, various known polyols commonly used in the manufacture of polyurethane resins can be used, and one or more types may be used in combination. For example, glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc.; 2-methyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, 2-butyl-2-ethyl Branched glycols such as -1,3-propanediol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptanediol, and 2-methyl-1,8-octanediol; low molecular weight polyols such as glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, and sorbitol.

[0211] Polyether polyols of polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, etc.; polyester polyols obtained by dehydration condensation or polymerization of the above low molecular weight polyols with petroleum-derived polycarboxylic acids such as sebacic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, superiic acid, azelaic acid, trimellitic acid, pyromellitic acid, or their anhydrides; polyester polyols obtained by ring-opening polymerization of cyclic ester compounds, such as lactones such as polycaprolactone, polyvalerolactone, and poly(β-methyl-γ-valerolactone); the above low molecular weight poly Examples include polycarbonate polyols obtained by the reaction of riols with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene; polybutadiene glycols; glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A; and acrylic polyols, castor oil polyols, hydrogenated castor oil polyols, dimer ols, hydrogenated dimer ols, etc., obtained by copolymerizing one or more hydroxyethyl acrylates, hydroxypropyl acrylates, hydroxybutyl acrylates, etc., or their corresponding methacrylic acid derivatives, etc., with, for example, acrylic acid, methacrylic acid, or their esters.

[0212] As the general-purpose polyols mentioned above, plant-derived raw materials can also be used. Using plant-derived polyols is preferable because it allows for an increase in the biomass content of liquid printing inks. Specifically, examples include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, pentylene glycol, 1,10-dodecanediol, dimer diol, isosorbide, and the like.

[0213] (Polyisocyanate) Diisocyanate compounds are preferred as the polyisocyanates used in the polyurethane resin in the above-mentioned liquid printing inks. Examples include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates commonly used in the production of polyurethane resins. For example, 1,3-phenylenediisocyanate, 1,4-phenylenediisocyanate, 1-methyl-2,4-phenylenediisocyanate, 1-methyl-2,6-phenylenediisocyanate, 1-methyl-2,5-phenylenediisocyanate, 1-methyl-2,6-phenylenediisocyanate, 1-methyl-3,5-phenylenediisocyanate, 1-ethyl-2,4-phenylenediisocyanate, 1-isopropyl-2,4-phenylenediisocyanate, 1,3-dimethyl-2,4-phenylenediisocyanate, 1,3-dimethyl-4,6-phenylenediisocyanate, 1,4-dimethyl-2,5-phenylenediisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene Aromatic polyisocyanates such as zen diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methylnaphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, biphenyl-4,4'-diisocyanate, 3-3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and diphenylmethane-2,4-diisocyanate;Aliphatic or alicyclic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclopentylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di(isocyanate methyl)cyclohexane, 1,4-di(isocyanate methyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, and 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate can be used. These polyisocyanates may be used individually or in combination of two or more types. Among these, aliphatic polyisocyanates and / or alicyclic polyisocyanates are preferred because they provide moderate flexibility, and isophorone diisocyanate or hexamethylene diisocyanate are even more preferred because they further improve adhesive strength.

[0214] As the polyisocyanate mentioned above, plant-derived raw materials can also be used. Using plant-derived polyisocyanates is preferable because it increases the biomass content of liquid printing inks. Specifically, examples include 1,5-pentamethylene diisocyanate and dimer isocyanate.

[0215] (Other components of polyurethane resin) As chain extenders used in the polyurethane resin in the above liquid printing ink, diamine compounds such as ethylenediamine, propylenediamine, tetramethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, diethylenetriamine, triethylenetetratriamine, toluylenediamine, and xylenediamine can be used, as well as amines having a hydroxyl group in the molecule, such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypyropyrethylenediamine, di-2-hydroxypyropyrethylenediamine, and di-2-hydroxypropylethylenediamine. These chain extenders can be used individually or in combination of two or more.

[0216] Furthermore, examples of reaction stoppers include polyamine compounds, dialkylamines such as di-n-butylamine, and alcohols such as ethanol and isopropyl alcohol. Using a polyamine compound as a reaction inhibitor is preferable because it allows for a higher pigment concentration in the ink due to its pigment dispersion effect. The polyamine compound is preferably one having either a primary or secondary amino group at its terminus. Examples include ethylenediamine, propylenediamine, tetramethylenediamine, hexamethylenediamine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, diethylenetriamine, triethylenetetratriamine, toluylenediamine, xylenediamine, N-(2-hydroxyethyl)ethylenediamine, and N-(2-hydroxyethyl)propyleneamine. Furthermore, when it is desired to introduce carboxyl groups into polyurethane resin, amino acids such as glycine and L-alanine can be used as reaction stoppers. These end-chain agents can be used individually or in combination of two or more.

[0217] (Synthesis of polyurethane resin) The polyurethane resin used in the above liquid printing ink is obtained by reacting various polyols, polyisocyanates, and chain extenders, and optionally end-capping agents. For example, the polyester polyol, along with the polyether polyol and general-purpose polyol as needed, and the polyisocyanate are reacted in a proportion that results in an excess of isocyanate groups to obtain a prepolymer with terminal isocyanate groups. The resulting prepolymer is then reacted with a chain extender and / or end-canceling agent in a suitable solvent, such as an ester solvent commonly used as a solvent for liquid printing inks, such as ethyl acetate, propyl acetate, or butyl acetate; a ketone solvent such as acetone, methyl ethyl ketone, or methyl isobutyl ketone; an alcohol solvent such as methanol, ethanol, isopropyl alcohol, or n-butanol; a hydrocarbon solvent such as toluene, xylene, methylcyclohexane, or ethylcyclohexane; or a mixed solvent thereof, in a two-step process. Alternatively, the polyester polyol, polyisocyanate, along with the polyether polyol and general-purpose polyol as needed, and the chain extender and / or end-canceling agent are reacted in a single step in a suitable organic solvent from among the above.

[0218] The weight-average molecular weight of the polyurethane resin is preferably in the range of 10,000 to 100,000. If the weight-average molecular weight of the polyurethane resin is 10,000 or higher, the blocking resistance of the resulting ink, the strength and oil resistance of the printed film will not be significantly reduced, and sufficient lamination strength can be obtained. If the viscosity is 100,000 or less, the resulting ink viscosity will not become too high, and the gloss of the printed film will be easier to maintain. The weight-average molecular weight of the polyurethane resin is shown as the value obtained by measuring it in the same manner as the number-average molecular weight of the polyester polyol described above.

[0219] The content of the above polyurethane resin in the total amount of the ink is preferably 3% by mass or more based on the total amount of the composition from the viewpoint of ensuring sufficient adhesion of the ink to the printed substrate, and 25% by mass or less from the viewpoints of appropriate ink viscosity and work efficiency during ink production and printing, and more preferably in the range of 5 to 15% by mass. In addition, when a polyurethane resin is used in combination in the liquid printing ink, it is preferable that the total of the content ratios of each polyurethane resin to the total amount of the ink is 3 to 25% by mass or less, and more preferably in the range of 5 to 15% by mass.

[0220] (Other resins in the liquid printing ink) Other resins other than the polyurethane resin may be added to the above liquid printing ink. Examples of the other resins other than the polyurethane resin include general-purpose resins frequently used in gravure inks or flexographic inks. Specifically, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-acrylic copolymer resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyamide resins, acrylic resins, polyester resins, alkyd resins, polyvinyl chloride resins, rosin-based resins, rosin-modified maleic acid resins, ketone resins, cyclized rubber, chlorinated rubber, butyral, petroleum resins, etc. can be mentioned. These resins that can be used in combination can be used alone or in combination of two or more. The content of the resins that can be used in combination is preferably 0.5 to 25% by mass based on the total mass of the ink, and more preferably 1 to 15% by mass.

[0221] (Hardener) In addition, the above urethane resin and a hardener may be used in combination. As the hardener, a general-purpose hardener used in organic solvent-based gravure printing inks may be used, but the most commonly used is an isocyanate-based hardener. The addition amount of the isocyanate compound is preferably in the range of 0.3% by mass to 10.0% by mass based on the non-volatile components of the liquid printing ink from the viewpoint of curing efficiency, and more preferably 1.0% by mass to 7.0% by mass.

[0222] (Organic solvents) There are no particular restrictions on the organic solvent used in the above-mentioned liquid printing ink; any known organic solvent can be used. Generally, due to both the need for hygiene during printing and the potential for harm to packaging materials, ethyl acetate, propyl acetate, isopropanol, and n-propanol are often used.

[0223] Water may be added to the above-mentioned liquid printing ink as a volatile component, along with the above-mentioned organic solvent. By adding water, the drying time of the ink can be controlled, and in gravure printing in particular, the characteristic low ink transfer in gradient areas can be reproduced beautifully. The amount of water added is preferably in the range of 0.3 to 10% by mass of the total liquid printing ink, in order to achieve good printability. If the amount of water added is 0.3% by mass or more, the reproducibility of the gradient area tends to be good without a decrease in the ink drying suppression effect, and if the amount of water added is 10% by mass or less of the total ink volume, the decrease in ink stability can also be suppressed. Furthermore, adding water in this way can reduce the amount of organic solvents used, contributing to environmental sustainability. The water may be added to the organic solvent beforehand to form a hydrous organic solvent, or a specific amount may be added separately.

[0224] (Coloring agent) The above liquid printing ink contains a coloring agent and can be used as an ink containing a coloring agent for design printing, etc., for the purpose of imparting aesthetic appeal. Examples of colorants include inorganic pigments, organic pigments, and dyes used in general inks, paints, and recording materials, with pigments being preferred. Examples of organic pigments include soluble azo pigments, insoluble azo pigments, azo pigments, phthalocyanine pigments, halogenated phthalocyanine pigments, anthraquinone pigments, anthancerone pigments, dianthaquinonyl pigments, anthrapyrimidine pigments, perylene pigments, perinone pigments, quinacridone pigments, thioindigo pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, azomethine azo pigments, flavanthrone pigments, diketopyrrolopyrrole pigments, isoindoline pigments, indanthrone pigments, and carbon black pigments. Other examples include carmine 6B, lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, chromophthal yellow, chromophthal red, phthalocyanine blue, phthalocyanine green, dioxazine violet, quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow, thioindigobordeaux, thioindigomagenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, and daylight fluorescent pigments. Furthermore, both untreated and acid-treated pigments can be used.

[0225] Examples of inorganic pigments include white inorganic pigments such as titanium dioxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, litsubone, antimony white, and gypsum. Among inorganic pigments, the use of titanium dioxide is particularly preferred. Titanium dioxide is white in color and is preferred in terms of coloring ability, opacity, chemical resistance, and weather resistance. From the viewpoint of printing performance, it is preferable that the titanium dioxide is treated with silica and / or alumina. Examples of inorganic pigments other than white include aluminum particles, mica, bronze powder, chrome vermilion, lead yellow, cadmium yellow, cadmium red, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, iron black, and zircon. Aluminum is available in powder or paste form, but it is preferable to use it in paste form for ease of handling and safety. Whether to use leafing or non-leafing aluminum is selected as appropriate from the viewpoint of brightness and density.

[0226] The above-mentioned pigment is preferably included in an amount sufficient to ensure the concentration and coloring power of the liquid printing ink, i.e., 1 to 60% by mass relative to the total mass of the ink, or 10 to 90% by mass in terms of the weight ratio of non-volatile components in the ink. Furthermore, these pigments can be used individually or in combination of two or more types.

[0227] (Other components in liquid printing ink) The above liquid printing ink may also contain, as needed, chelating crosslinking agents, extender pigments, pigment dispersants, leveling agents, defoaming agents, waxes, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, etc.

[0228] (Biomass liquid printing ink) In the above-mentioned liquid printing ink, it is preferable to use biomass polyurethane synthesized from plant-derived raw materials, taking into consideration the construction of a sustainable circular society (sustainability) that should be developed in a sustainable manner. For example, a polyester polyol (which may be referred to as a biopolyester polyol hereafter) that uses plant-derived 1,2-propanediol, 2-methyl-1,3-propanediol, or 3-methyl-1,5-pentanediol as a reaction raw material with a plant-derived polycarboxylic acid is preferred as a biopolyurethane.

[0229] Furthermore, the biomass content of the above-mentioned liquid printing ink can be increased by appropriately using biomass raw materials as raw materials. Examples of biomass raw materials for polyurethane resins include polycarboxylic acids such as succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dimer acid, glutaric acid, and malic acid; polyols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, pentylene glycol, 1,10-dodecanediol, dimer ol, and isosorbide; and polyisocyanates such as 1,5-pentamethylene diisocyanate and dimer isocyanate. Other biomass raw materials include rosin, dammar resin, cellulose acetate propionate resin, nitrated cotton, and lactic acid.

[0230] Commercially available biomass liquid printing inks can also be used. Commercially available inks and other materials listed by the Japan Organic Resources Association can be used.

[0231] (Barrier layer) The laminate of the present invention may include a barrier layer. Examples of barrier layers include aluminum layers, vapor-deposited layers, and gas barrier resin layers.

[0232] For applications where transparency is not required, an aluminum layer made of aluminum foil can be used alone or in combination as a barrier layer.

[0233] (vapor deposited layer) The laminate of the present invention may have a vapor-deposited layer made of inorganic material and / or inorganic oxide as a barrier layer. By using the vapor-deposited layer, barrier properties can be imparted to the laminate of the present invention. The vapor-deposited layer can be formed using known inorganic materials or inorganic oxides by known methods, and its composition and formation method are not particularly limited. Furthermore, the laminate of the present invention may have two or more vapor-deposited films, which may have the same composition or different compositions.

[0234] As the above-mentioned vapor-deposited layer, for example, a vapor-deposited film of an inorganic substance or inorganic oxide such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), or yttrium (Y) can be used. Furthermore, vapor-deposited films of inorganic oxides such as silicon oxide and aluminum oxide are transparent.

[0235] The inorganic oxides mentioned above are denoted as MOx (where M represents an inorganic element), such as SiOx and AlOx. The value of x can take on the following ranges: silicon (Si) 0-2, aluminum (Al) 0-1.5, magnesium (Mg) 0-1, calcium (Ca) 0-1, potassium (K) 0-0.5, tin (Sn) 0-2, sodium (Na) 0-0.5, boron (B) 0-1.5, titanium (Ti) 0-2, lead (Pb) 0-1, zirconium (Zr) 0-2, and yttrium (Y) 0-1.5. In the above, when x=0, it represents a completely inorganic element (pure substance), which is not transparent, and when the value of x is at the upper limit of the range, it indicates that it is completely oxidized. Silicon (Si) and aluminum (Al) are preferably used as the vapor-deposited layer. For silicon (Si), x values ​​in the range of 1.0 to 2.0 can be used, and for aluminum (Al), x values ​​in the range of 0.5 to 1.5 can be used.

[0236] The above-mentioned vapor-deposited layer can be formed on the surface of the substrate or the like by methods such as physical vapor deposition (PVD), including vacuum deposition, sputtering, and ion plating, or chemical vapor deposition (CVD), including plasma chemical vapor deposition, thermochemical vapor deposition, and photochemical vapor deposition.

[0237] The thickness of the above-mentioned vapor-deposited layer is not particularly limited as long as the vapor-deposited layer alone can exhibit a certain level of gas barrier function. The preferred thickness range varies depending on the type of metal or metal oxide being deposited, but is preferably 0.05 to 70 nm, more preferably 0.1 to 70 nm, even more preferably 3 to 70 nm, and even more preferably 5 to 60 nm.

[0238] A metal vapor-deposited film may be used as the vapor-deposited layer. As metal-deposited films, VM-CPP films, which are CPP films coated with metal such as aluminum, and VM-OPP films, which are OPP films coated with metal such as aluminum, can be used. Furthermore, examples of the transparent vapor-deposited films mentioned above include films obtained by vapor-depositing silica or alumina onto OPP film, PET film, nylon film, etc. A film with a coating applied to the vapor-deposited layer may be used for purposes such as protecting the inorganic vapor-deposited layer of silica or alumina.

[0239] (Gas barrier resin layer) A gas barrier resin layer can be obtained, for example, by applying a gas barrier coating agent containing a vinyl alcohol-based polymer and an aqueous solvent using a known coating method to form a coating film. The coating method is not particularly limited, and can be spray, spin coat, dip, roll coat, blade coat, doctor roll, doctor blade, curtain coat, slit coat, screen printing, inkjet, dispensing, die coat (die coating), direct gravure, reverse gravure, flexographic, knife coat, dot coat, etc.

[0240] Specific examples of vinyl alcohol polymers include polyvinyl alcohol, ethylene vinyl alcohol, and polyvinyl butyral. The vinyl alcohol polymer may have reactive functional groups other than hydroxyl groups, such as acetoacetyl groups, carboxyl groups, anionic carboxyl groups, sulfonic acid groups, and anionic sulfonic acid groups. These may be used individually or in combination of two or more types.

[0241] Examples of vinyl alcohol polymers include hydrolysates of vinyl ester homopolymers or copolymers, and compounds obtained by reacting hydrolysates of vinyl ester homopolymers or copolymers with an aldehyde or ketone to form acetals. Examples of vinyl alcohol polymers having reactive functional groups other than hydroxyl groups include hydrolysates of copolymers of vinyl esters and monomers having reactive functional groups, and modified versions of vinyl ester homopolymers or copolymer hydrolysates in which the hydroxyl or acetyl groups are modified using compounds having reactive functional groups by known methods.

[0242] Examples of vinyl esters include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, vinyl benzoate, and vinyl acetoacetate, and can be used individually or in combination of two or more. It is preferable to use vinyl acetate.

[0243] Polymerizable compounds copolymerizable with vinyl esters include ethylene, propene, 1-butene, isobutylene, 1,3-butadiene, isopropenyl acetate, 2-propenyl acetate, styrene, α-methylstyrene, vinyl chloride, acrylonitrile, maleic anhydride, methyl acrylate, methyl methacrylate, N-vinyl-N-methylformamide, vinylacetamide, N-vinylformamide, N-(hydroxymethyl)-N-vinylformamide, hydroxyethyl acrylate, methyl vinyl ketone, diacetone acrylamide, and diacetone acrylamide. Examples include diacetone methacrylamide, acrolein, formyl styrene, vinyl methyl ketone, vinyl ethyl ketone, vinyl isobutyl ketone, diacetone acrylate, diacetone methacrylate, acetonitrile acrylate, 2-hydroxypropyl acrylate acetoacetate, butanediol acrylate acetate, vinyl sulfonic acid, acrylamide tert-butyl sulfonic acid, orthostyrene sulfonic acid, metastyrene sulfonic acid, parastyrene sulfonic acid, etc., and can be used individually or in combination of two or more. In particular, ethylene, isopropenyl acetate, and 2-propenyl acetate are preferred.

[0244] When vinyl esters and polymerizable compounds are used in combination, the amounts used can be adjusted as appropriate. However, from the viewpoint of gas barrier properties, it is preferable to limit the amount of polymerizable compounds to 60 mol% or less of the total amount of vinyl esters and polymerizable compounds, and more preferably to 25 mol% or less.

[0245] The degree of polymerization of the vinyl ester polymer, which is a precursor of the vinyl alcohol polymer, is not particularly limited, but is 500 to 10000 as an example, more preferably 800 to 6000, and more preferably 1000 to 3000. This makes it possible to create a coating agent with an excellent balance of gas barrier properties and coating suitability.

[0246] Vinyl alcohol-based polymers have excellent gas barrier properties, so it is preferable that they have a degree of saponification of 90% or more, and preferably 95% or more. 100% is also acceptable. The degree of saponification can be measured by FTIR using, for example, a Nicolet5700FTIR spectrometer controlled by OMNIC software.

[0247] When vinyl alcohol polymers are acetalized, examples of aldehydes used for acetalization include aliphatic aldehydes such as formaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, octylaldehyde, and dodecylaldehyde; alicyclic aldehydes such as cyclohexanecarbolaldehyde; aromatic aldehydes such as benzaldehyde, naphthaldehyde, anthraldehyde, phenylacetaldehyde, tolualdehyde, dimethylbenzaldehyde, cuminaldehyde, and benzylaldehyde; unsaturated aldehydes such as cyclohexenealdehyde, dimethylcyclohexenealdehyde, and acrolein; heterocyclic aldehydes such as furfural and 5-methylfurfural; hemiacetals such as glucose and glucosamine; and aldehydes containing an amino group such as 4-aminobutyraldehyde. Examples of ketones include aliphatic ketones such as 2-propanone, methyl ethyl ketone, 3-pentanone, and 2-hexanone; alicyclic ketones such as cyclopentanone and cyclohexanone; and aromatic ketones such as acetophenone and benzophenone. These can be used individually or in combination of two or more types.

[0248] As acid catalysts used in acetalization, conventionally known organic acids and inorganic acids such as acetic acid, p-toluenesulfonic acid, nitric acid, sulfuric acid, and hydrochloric acid can be used.

[0249] The vinyl alcohol-based polymer is preferably obtained by acetalizing a precursor with a degree of saponification of 95% or more.

[0250] Methods for modifying the hydroxyl or acetyl groups of hydrolysates of vinyl ester homopolymers or copolymers include, for example, directly reacting gaseous or liquid diketene, pre-adsorbing an organic acid such as acetic acid and then reacting it with gaseous or liquid diketene under an inert gas atmosphere, or spraying a mixture of organic acid and diketene and reacting it (reaction generation step), then washing off unreacted diketene with an alcohol having 1 to 3 carbon atoms (washing step), and then drying under predetermined conditions (drying step), as well as transesterification by reacting the hydrolysate of vinyl ester homopolymers or copolymers with acetoacetate ester. This allows for the introduction of acetoacetyl groups into vinyl alcohol-based polymers.

[0251] Examples of aqueous solvents include water, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol; diols such as butanediol, pentanediol, and hexanediol; glycol esters such as propylene glycol laurate; diethylene glycol ethers such as diethylene glycol monoethyl, diethylene glycol monobutyl, diethylene glycol monohexyl, and carbitol; glycol ethers such as cellosolve containing propylene glycol ether, dipropylene glycol ether, and triethylene glycol ether; alcohols such as methanol, ethanol, isopropyl alcohol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, butyl alcohol, and pentyl alcohol; sulfolanes, esters, ketones, lactones such as γ-butyrolactone, lactams such as N-(2-hydroxyethyl)pyrrolidone, glycerin, and its polyalkylene oxide adducts. Water-based solvents can be used alone or in combination of two or more types.

[0252] Crosslinking agents include aldehydes such as formaldehyde, oxalaldehyde, and glutaraldehyde; acetals such as diacetal compounds of glutaraldehyde; aliphatic polyisocyanates represented by hexamethylene diisocyanate and its derivatives (adduct, nurate, burette, etc.); aromatic aliphatic polyisocyanates represented by xylylene diisocyanate and its derivatives; aromatic polyisocyanates represented by toluene diisocyanate and its derivatives; isocyanates such as urethane prepolymers which are reaction products of these isocyanates with polyols; epoxys; organometallic compounds of titanium, silicon, aluminum, zirconium, boron, etc. with alkoxides, etc.; methylolurea, methylolmelamine, etc. Examples include ureas; carboxyl group-containing polymers such as polyacrylic acid polymers and maleic anhydride polymers; carbodiimides such as p-phenylene-bis(2,6-xylylcarbodiimide), tetramethylene-bis(t-butylcarbodiimide), and cyclohexane-1,4-bis(methylene-t-butylcarbodiimide); hydrazine compounds such as methylenedihydrazine, ethylenedihydrazine, propylenedihydrazine, butylenedihydrazine, oxalate dihydrazide, malonate dihydrazide, succinate dihydrazide, glutarate dihydrazide, adipic acid dihydrazide, and sebacate dihydrazide; hydrazide compounds such as adipic acid dihydrazide, carbodihydrazide, and polyhydrazide; boric acid; and titanium lactate. The isocyanates may be blocked isocyanates using a known blocking agent, or emulsion-type isocyanates may be used.

[0253] The amount of crosslinking agent is adjusted as appropriate, but one example is 0.5 to 30 parts by mass per 100 parts by mass of vinyl alcohol polymer.

[0254] As an adhesion enhancer that can improve adhesion to substrates, particularly olefin-based resin substrates, imine resins such as polyalkylene imines can also be used in combination. Polyalkyleneimines are resins having a polyalkyleneimine skeleton and can be obtained by polymerizing one or more alkyleneimines (e.g., ethyleneimine, propyleneimine) by conventional methods. Polyalkyleneimine (A2) may be a linear polyalkyleneimine consisting of linear polyalkyleneimine chains, or a branched polyalkyleneimine having branched polyalkyleneimine chains. Examples of polyalkyleneimines (A2) include polyethyleneimine and polypropyleneimine. Polyalkyleneimine (A2) may also be a polyalkyleneimine chain in which substituents (e.g., hydroxypropyl group, hydroxyethyl group) are introduced to at least some of the nitrogen atoms. Modified versions with organometallic compounds such as tetraisopropyl titanate, tetran-butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, tetramethyl titanate, polyhydroxytitanium stearate, titanium bisacetylacetonate, titanium tetraacetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium ethylacetoacetate, titanium lactate, titanium triethanolamine, and titanium stearate may also be used, and two or more polyalkyleneimines may be used in combination.

[0255] Polyalkyleneimine (A2) is thought to contribute to improving the adhesion between the vinyl alcohol polymer (A1) and the olefin film through its amino groups (NHR groups, NH2 groups) and ethylene groups. Since it is effective in improving adhesion, it is preferable that polyalkyleneimine (A2) contains branched polyalkyleneimine. The degree of branching of polyalkyleneimine (A2) can be expressed by the proportion of primary, secondary, and tertiary amino groups it possesses. The composition can be adjusted as appropriate depending on the vinyl alcohol polymer (A1) used and its proportion, but as an example, it is preferable to use a polyalkyleneimine (A2) in which the proportion of primary amino groups is 20-40%, secondary amino groups is 30-60%, and tertiary amino groups is 20-35%. The proportion of primary, secondary, and tertiary amine groups in polyalkylene imine (A2) can be measured by 13C-NMR spectroscopy. The branched polyalkyleneimine is preferably a branched polyethyleneimine.

[0256] The number-average molecular weight of polyalkyleneimine (A2) is preferably 5,000 or more, more preferably 9,000 or more, and even more preferably 50,000 or more, due to its excellent adhesion properties. There is no particular upper limit, but one example is 100,000 or less. The number-average molecular weight of polyalkyleneimine (A2) was measured using GPC (gel permeation chromatography) with pullulan as the standard substance.

[0257] In the coating agent of the present invention, the amount of polyalkylimine (A2) blended is preferably 1% by mass or more and 90% by mass or less of the total amount of vinyl alcohol polymer (A1) and polyalkylimine (A2). This makes it possible to more reliably improve the adhesion of the coating agent to olefin-based substrates while maintaining its gas barrier properties. More preferably, the amount is 10% by mass or more and 50% by mass or less. If the coating agent of the present invention does not contain polyalkyleneimine (A2), its adhesion to olefin-based substrates is insufficient. If the vinyl alcohol polymer (A1) is not included (i.e., the resin (A) consists only of polyalkyleneimine (A2)), the coating film is sticky and unsuitable for post-processing.

[0258] The amount of gas barrier coating agent applied should be adjusted as appropriate depending on the desired degree of gas barrier effect, but one example is 0.1 g / m².2 ~5.0g / m 2 More preferably 0.3 g / m 2 ~2.0g / m 2 That is the case.

[0259] Commercially available gas barrier coating agents can also be used, including, for example, Exevia (registered trademark) from Sumitomo Chemical, the SunBar (registered trademark) series from Sun Chemical, the Takelac WPB (registered trademark) series from Mitsui Chemicals, and LG-OX from Tokyo Ink Co., Ltd.

[0260] The above-mentioned gas barrier resin layer may mainly consist of a reaction product of a polyester polyol (Y1), which is a reaction product of an acid component containing an ortho-orienting polycarboxylic acid or a meta-orienting polycarboxylic acid, and a polyol component, and an isocyanate compound (B).

[0261] (Acid component: ortho-directing polycarboxylic acid or meta-directing polycarboxylic acid) Examples of ortho-directing polycarboxylic acids used in the synthesis of polyester polyol (Y1) include orthophthalic acid or its acid anhydride, naphthalene 2,3-dicarboxylic acid or its acid anhydride, naphthalene 1,2-dicarboxylic acid or its acid anhydride, anthraquinone 2,3-dicarboxylic acid or its acid anhydride, and 2,3-anthracenecarboxylic acid or its acid anhydride. These compounds may have substituents on any carbon atom of the aromatic ring. Examples of substituents include chloro group, bromo group, methyl group, ethyl group, i-propyl group, hydroxyl group, methoxy group, ethoxy group, phenoxy group, methylthio group, phenylthio group, cyano group, nitro group, amino group, phthalimide group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, or naphthyl group.

[0262] Furthermore, examples of meta-directing polycarboxylic acids used in the synthesis of polyester polyol (Y1) include isophthalic acid and 1,3-naphthalenedicarboxylic acid. These compounds may have substituents on any carbon atom of the aromatic ring. Examples of substituents include chloro group, bromo group, methyl group, ethyl group, i-propyl group, hydroxyl group, methoxy group, ethoxy group, phenoxy group, methylthio group, phenylthio group, cyano group, nitro group, amino group, phthalimide group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, or naphthyl group.

[0263] (Acid components and other polycarboxylic acids) The polycarboxylic acid used as the acid component in the synthesis of polyester polyol (Y1) may include polycarboxylic acids other than the ortho-directing polycarboxylic acid or meta-directing polycarboxylic acid mentioned above. These polycarboxylic acids include aliphatic polycarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid; unsaturated polycarboxylic acids such as maleic anhydride, maleic acid, and fumaric acid; alicyclic polycarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; terephthalic acid, pyromellitic acid, trimellitic acid, 1,4-naphthalenedicarboxylic acid, 1,5-anthracenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, and 1,4-anthracenedicarboxylic acid. Examples include aromatic polycarboxylic acids such as spiral dicarboxylic acid, 2,6-anthracenedicarboxylic acid, 2,7-anthracenedicarboxylic acid, 1,8-anthracenedicarboxylic acid, 9,10-anthracenedicarboxylic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid and acid anhydrides or ester-forming derivatives of these dicarboxylic acids, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and ester-forming derivatives of these dihydroxycarboxylic acids, and one or more of these can be used in combination. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid, and their acid anhydrides are preferred.

[0264] When the polycarboxylic acid includes polycarboxylic acids other than ortho-directing polycarboxylic acids or meta-directing polycarboxylic acids, it is preferable that the proportion of ortho-directing polycarboxylic acids or meta-directing polycarboxylic acids to the total amount of polycarboxylic acids is 40 to 100% by mass.

[0265] (Polyol component) The polyol component polyhydric alcohol used in the synthesis of polyester polyol (Y1) preferably includes dihydric alcohols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol, as well as trihydric alcohols such as glycerol, trimethylolethane, and trimethylolpropane. In particular, it is more preferable that the mixture contains ethylene glycol or glycerol. It is especially preferable that the product contains glycerol. Glycerol is preferably contained in the polyol component of polyol (A) in an amount of 10 to 100% by mass.

[0266] Polyhydric alcohols other than those listed above may be used in combination. Examples include aliphatic diols such as 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol; trihydric or higher polyhydric alcohols such as glycerin, trimethylolpropane, trimethylolethane, tris(2-hydroxyethyl) isocyanurate, 1,2,4-butanetriol, pentaerythritol, and dipentaerythulitol; hydroquinone, resorcinol, catechol, naphthalenediol, biphenol, bisphenol A, hisphenol F, tetramethylbiphenol, and aromatic polyhydric phenols such as ethylene oxide extensions thereof and hydrogenated alicyclic groups.

[0267] If the polyester polyol (Y1) has three or more hydroxyl groups (referred to as polyester polyol (Y1) for convenience), some of the hydroxyl groups may be modified with acid groups. Such polyester polyols will also be referred to as polyester polyol (A1') below. Polyester polyol (A1') is obtained by reacting polyester polyol (Y1) with a polycarboxylic acid or its acid anhydride. The proportion of hydroxyl groups modified by the polycarboxylic acid is preferably 1 / 3 or less of the total hydroxyl groups present in the polyester polyol (Y1). Examples of polycarboxylic acids used for modification include, but are not limited to, succinic anhydride, maleic acid, fumaric acid, 1,2-cyclohexanedicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, phthalic anhydride, 2,3-naphthalenedicarboxylic anhydride, trimellitic anhydride, oleic acid, and sorbic acid.

[0268] The hydroxyl value of the polyester polyol (Y1) is preferably 20 mg KOH / g or more and 250 mg KOH / g or less. If the hydroxyl value is less than 20 mgKOH / g, the molecular weight is too large, resulting in a high viscosity of the polyol composition (X), which necessitates a higher coating temperature when applied, for example, as a solvent-free adhesive. If the hydroxyl value exceeds 250 mgKOH / g, the crosslinking density of the cured coating may become too high, potentially reducing the adhesive strength.

[0269] When the polyester polyol (Y1) has an acidic group, the acid value is preferably 200 mg KOH / g or less. If the acid value exceeds 200 mgKOH / g, the reaction between the polyol and polyisocyanate may proceed too quickly, potentially reducing the coating suitability. There is no particular lower limit to the acid value, but one example is 20 mg KOH / g or higher. When the acid value is 20 mg KOH / g or higher, good gas barrier properties and initial cohesive force can be obtained due to intermolecular interactions. The hydroxyl value of polyester polyol (A) can be measured using the hydroxyl value measurement method described in JIS-K0070, and the acid value can be measured using the acid value measurement method described in JIS-K0070.

[0270] A number-average molecular weight of 300 to 5000 for the polyester polyol (Y1) is particularly preferable because it provides a crosslinking density that offers an excellent balance between adhesiveness and gas barrier properties. A more preferable number-average molecular weight is 350 to 3000. The number-average molecular weight is calculated from the obtained hydroxyl value and the number of functional groups of hydroxyl groups in the design.

[0271] The glass transition temperature of the polyester polyol (Y1) is preferably -30°C to 80°C, more preferably 0°C to 60°C, and even more preferably 25°C to 60°C, in order to balance adhesion to the substrate and gas barrier properties.

[0272] The polyester polyol (Y1) may also be a polyester polyurethane polyol with a number average molecular weight of 1,000 to 15,000, obtained by urethane elongation through reaction with a diisocyanate compound. Polyester polyols stretched with urethane contain a certain amount of molecular weight components and urethane bonds, resulting in excellent gas barrier properties and superior initial cohesive strength.

[0273] The above polyester polyol (Y1) may be used as a single type, or a combination of multiple polyol types may be used.

[0274] (Isocyanate compound (B)) The above-mentioned isocyanate compound (B) can be any conventionally known compound without particular limitation, and examples include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, or trimers of these isocyanate compounds, and adducts obtained by reacting an excess amount of these isocyanate compounds with low molecular weight active hydrogen compounds such as ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, metaxylylenediamine and their alkylene oxide adducts, various polyester resins, polyether polyols, polyamides, and other high molecular weight active hydrogen compounds. Polyester polyisocyanates obtained by reacting polyester polyols (Y1) to (A3) with a diisocyanate compound in an isocyanate excess ratio of hydroxyl groups to isocyanate groups may also be used. These can be used individually or in combination of two or more types.

[0275] Alternatively, blocked isocyanates may be used as the isocyanate compound. Examples of isocyanate blocking agents include phenols such as phenol, thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol; oximes such as acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime; alcohols such as methanol, ethanol, propanol, and butanol; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; tertiary alcohols such as t-butanol and t-pentanol; and lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, and β-propyrolactam. Other examples include aromatic amines, imides, active methylene compounds such as acetylacetone, acetoacetate, and ethyl malonate, mercaptans, imines, ureas, diaryl compounds, and sodium bisulfite. Blocked isocyanates are obtained by an addition reaction between the above-mentioned isocyanate compound and an isocyanate blocking agent using a known and conventional method.

[0276] The above isocyanate compound (B) preferably has an aromatic ring or an aliphatic ring. The presence of aromatic or aliphatic rings can be expected to improve the gas barrier properties and blocking resistance of the coating film. In the above-mentioned isocyanate compounds, examples of isocyanate compounds having an aromatic ring or an aliphatic ring include toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, or trimers of these isocyanate compounds, and adducts obtained by reacting an excess amount of these isocyanate compounds with low molecular weight active hydrogen compounds such as ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, metaxylylenediamine and their alkylene oxide adducts, various polyester resins, polyether polyols, and high molecular weight active hydrogen compounds of polyamides.

[0277] The above isocyanate compound (B) may be used alone or in combination with several other isocyanate compounds.

[0278] Furthermore, when using a polyester polyol (A) that retains carboxylic acid groups, such as polyester polyol (A1'), an epoxy compound may be included in combination with the polyisocyanate compound. Epoxy compounds include diglycidyl ether of bisphenol A and its oligomers, diglycidyl ether of hydrogenated bisphenol A and its oligomers, diglycidyl orthophthalate, diglycidyl isophthalate, diglycidyl terephthalate, diglycidyl p-oxybenzoate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, diglycidyl succinate, diglycidyl adipicate, diglycidyl sebacate, ethylene glycol diglycidyl ether, and propylene glycol diglycidyl Examples include ethers, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidylpropylene urea, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, and triglycidyl ethers of glycerol alkylene oxide adducts.

[0279] When using epoxy compounds, a commonly known epoxy curing accelerator may be added as appropriate to accelerate curing, provided that the objectives of the present invention are not impaired.

[0280] The above gas barrier resin layer may preferably also contain a compound (C) having an active hydrogen group. In compounds (C) containing active hydrogen, the active hydrogen group may be a hydroxyl group, amino group, imino group, carboxylic acid, urea group, or SH group, etc. Among these, hydroxyl groups, amino groups, or SH groups are preferred.

[0281] Furthermore, if the solubility parameter of compound (C) is 29.5 or less, the compatibility between the polyol (A) and the isocyanate compound (B) improves, and by forming a coating film in which compound (C) is uniformly distributed, an improvement in gas barrier properties can be expected. In this invention, the solubility parameter is the δT value included in the Hansen Solubility Parameter Calculation Software (HSPiP) or the δT value calculated using the SMILES notation.

[0282] Furthermore, the number-average molecular weight of compound (C) is preferably in the range of 100 to 250.

[0283] As the compound (C) having a hydroxyl group as the active hydrogen group, examples include alkanols such as octanol and decanol, aliphatic diols such as 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, 3,3-dimethylolheptane, octanediol, decanediol, alicyclic alcohols such as 1,3- or 1,4-cyclohexanedimethanol, 1,3- or 1,4-cyclohexanediol, aromatic alcohols such as salicylic alcohol and vanillyl alcohol, hydrogenated bisphenol A, 1,4-dihydroxy-2-butene, Examples include dihydric alcohols such as 2,6-dimethyl-1-octen-3,8-diol, bisphenol A, diethylene glycol, triethylene glycol, and dipropylene glycol; trihydric alcohols such as glycerin, trimethylolpropane, and triisopropanolamine; tetrahydric alcohols such as tetramethylolmethane (pentaerythritol) and diglycerin; pentahydric alcohols such as xylitol; hexahydric alcohols such as sorbitol, mannitol, allitol, isitol, dalcitol, althritol, inositol, and dipentaerythritol; and heptahydric alcohols such as perseitol.

[0284] Examples of compounds (C) having an amino group as the active hydrogen group include aliphatic amines such as octylamine, decaneamine, 1,8-diaminooctane, and 1,10-diaminodecane; alicyclic amines such as isophoronediamine, norbornenediamine, bis(aminomethyl)cyclohexane, cyclohexanediamine, diaminodicyclohexylmethane, and methylenebis(methylcyclohexaneamine); and aromatic amines such as 1-xylylenediamine, N-benzylethylenediamine, phenylenediamine, diaminodiphenylmethane, diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, toluenediamine, and diethyltoluenediamine.

[0285] Examples of compounds (C) having an SH group as the active hydrogen group include hexyl mercaptan, heptyl mercaptan, octyl mercaptan, nonyl mercaptan, decyl mercaptan, undecyl mercaptan, dodecyl mercaptan, tridecyl mercaptan, tetradecyl mercaptan, pentadecyl mercaptan, mercaptophenol, mercaptopropionic acid, mercaptobutyric acid, 1,4-butanedithiol, 2-mercaptobenzothiazole, and 3 Examples include mercapto-1,2-propanediol, mercaptomethylbutanol, 3-mercapto-2-methylpentanol, 3-mercapto-3-methylbutanol, 4-ethoxy-2-methyl-2-butanethiol, hexanethiol, dimethylthiophenol, 1,4-bis(3-mercaptobutyryloxy)butane, trimethylolpropanetris(3-mercaptobutyrate), pentaerythritoltetrakis(3-mercaptobutyrate), etc.

[0286] The above compound (C) may be used alone or in combination of multiple types. Among these, compounds (C) having a hydroxyl group as the active hydrogen group are preferred, and isosorbide, tris(2-hydroxyethyl) isocyanurate, trimethylolpropane, dipentaerythritol, and 1,4-cyclohexanedimethanol are preferred.

[0287] The amount of compound (C) is preferably 0.5% by mass or more and 20% by mass or less relative to the nonvolatile components of the gas barrier resin layer. Within this range, it is expected that winding blocking during coating will be prevented, good adhesion to the substrate, and improved gas barrier properties of the coating film will be achieved. The amount of the compound is preferably 1% by mass or more and 15% by mass or less, and most preferably 2% by mass or more and 8% by mass or less.

[0288] (Other ingredients) The above gas barrier resin layer may contain a plate-like inorganic compound (E). When plate-shaped inorganic compounds (E) are used in combination, their plate-like shape improves barrier properties. Examples of plate-like inorganic compounds (E) used in the present invention include, for example, hydrated silicates (phyllosilicate minerals, etc.), kaolin, kaolinite-serpentine clay minerals (haloysite, kaolinite, endelite, dickite, nacrite, etc., antigorite, chrysotile, etc.), pyrophyllite-talc group (pyrophyllite, talc, kerolite, etc.), smectite clay minerals (montmorillonite, bydelite, Examples include nontronite, saponite, hectorite, souconite, stevensite, etc., vermiculite clay minerals (vermiculite, etc.), mica or mica clay minerals (muscovite, phlogopite, etc., margalite, tetrasilicic mica, teniolite, etc.), chlorite group (cuquerite, sudoite, clinochlore, chamosite, nimite, etc.), hydrotalcite, platy barium sulfate, boehmite, and aluminum polyphosphate. These minerals may be natural clay minerals or synthetic clay minerals. The plate-like inorganic compound (E) is used alone or in combination of two or more types. There are no particular restrictions on the aspect ratio, content within the coating agent, particle size, and particle size distribution of these plate-like inorganic compounds (E), as long as they provide barrier-enhancing functionality and blocking resistance.

[0289] The amount of plate-like inorganic compound (E) blended is preferably 5% by mass or more and 80% by mass or less relative to the nonvolatile components of the gas barrier resin layer. Within this range, improvements in the adhesion of the coating agent to the substrate, the appearance of the coating, and the gas barrier properties of the coating film are expected. The amount of the active ingredient is preferably between 10% and 60%, and most preferably between 20% and 50%.

[0290] The above gas barrier resin layer may also be used in combination with known acid anhydrides as additives to improve acid resistance. Examples of acid anhydrides include phthalic anhydride, succinic anhydride, hetic anhydride, hymicic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydric anhydride, tetrapromophthalic anhydride, tetrachlorophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenotetracarboxylic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 5-(2,5-oxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, and styrene-maleic anhydride copolymer. It is preferable that these acid anhydrides contain non-petroleum-derived components as raw materials, as this allows for a higher proportion of non-petroleum-derived components. An example of such a compound is succinic anhydride.

[0291] Furthermore, if necessary, materials with gas-capturing properties may be added. Examples of materials with oxygen-scavenging capabilities include low-molecular-weight organic compounds that react with oxygen, such as hindered phenols, vitamin C, vitamin E, organophosphorus compounds, gallic acid, and pyrogallol, as well as transition metal compounds such as cobalt, manganese, nickel, iron, and copper. Materials that possess water vapor capture capabilities include silica gel, zeolite, activated carbon, and calcium carbonate. In addition to these, components that capture the target gas to be blocked can also be added.

[0292] In addition, various additives may be included, as long as they do not impair the gas barrier auxiliary function. Examples of additives include inorganic fillers such as silica, alumina, aluminum flakes, and glass flakes; when using inorganic materials, dispersants, stabilizers (antioxidants, heat stabilizers, UV absorbers, etc.), adhesion enhancers, crosslinking agents, plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, leveling agents, and slip enhancers.

[0293] (Coating agent) The above-mentioned gas barrier resin layer can be obtained by applying a coating agent, which is a mixture of the polyol (A) and the isocyanate compound (B), in layers onto a substrate and then reacting it. Generally, polyol compounds and isocyanate compounds are highly reactive. Therefore, coating agents made from these materials are typically used as a "two-component curing type," where the polyol (A) and the isocyanate compound (B) are mixed immediately before coating. The gas barrier coating agent of the present invention is also typically used as a two-component curing type coating agent. The term "two liquids" as used herein refers to two liquids: a polyol composition (Y) containing the above-mentioned polyol (A) as the main component, and an isocyanate composition (B) containing the above-mentioned isocyanate compound (B) as the main component. Ko

[0294] When considering compounds or additives that can be used in combination, it is preferable to decide whether to incorporate them into the polyol (A) or the isocyanate compound (B) based on their reactivity. For example, the compound (C) having the aforementioned active hydrogen group is usually used in combination with a polyol composition (Y) because it has an active hydrogen group. Since the plate-like inorganic compound (E) does not particularly contribute to reactivity, it may be incorporated into either the polyol composition (Y) or the isocyanate composition (B). When formulating, known dispersion and mixing methods can be used.

[0295] In the above coating agent, it is preferable that the reactive component of the isocyanate compound contained in the isocyanate composition (B) and the hydroxyl group of the polyol contained in the polyol composition (Y) are blended in an equivalent ratio of 0.5 / 1 to 5 / 1, and more preferably 0.8 / 1 to 2.5 / 1 from the viewpoint of barrier function and blocking resistance. If the polyisocyanate component is excessive beyond the specified range, the excess polyisocyanate component tends to remain, resulting in poor blocking resistance. On the other hand, if there is too much polyester (B), the cured coating film becomes hard, and good adhesive strength may not be obtained.

[0296] (Solvent used in coating agents) A solvent may be used with the above coating agent as appropriate. The solvent used is preferably non-aqueous, and ideally, an organic solvent should be the main component, in order to provide fast drying and water vapor barrier properties. Specifically, it is desirable that the solvent has high solubility in the main component, polyester, and also has minimal residual solvent and dries quickly. From this perspective, organic solvents with a boiling point of 100°C or lower are preferred. Examples of organic solvents that can be preferably used include ethyl acetate, propyl acetate, and butyl acetate as ester solvents; acetone and 2-butanone as ketone solvents; tetrahydrofuran as ether solvents; hexane and cyclohexane as aliphatic solvents; and toluene as aromatic solvents. When mixing in alcohol-based solvents or water, it is preferable to minimize their use, as isocyanate compounds are used in combination as curing agents.

[0297] The thickness of the gas barrier resin layer is preferably selected from a range of, for example, 0.05 μm to 30 μm.

[0298] (packaging material) The laminate of the present invention can be used as packaging material for food, pharmaceuticals, etc., by using the sealant film of the present invention as the sealant. When used as packaging material, the layer configuration may change depending on the contents, usage environment, and usage form. Furthermore, the packaging of the present invention may be appropriately provided with an easy-open treatment or resealing means. The packaging material comprising a laminate containing the sealant film of the present invention has good sealing properties, as well as good heat resistance, transparency, and impact resistance, making it particularly suitable for use as a packaging material for retort packaging of food.

[0299] As an example of the packaging material of the present invention, the sealant film of the present invention can be obtained by overlapping the surfaces of the sealant film of the present invention facing each other, and then heat-sealing the peripheral edges to form a bag. As for the bag-making method, the laminate of the present invention can be folded or overlapped so that the inner layer surfaces (sealant layer surfaces) face each other, and the peripheral edges can be heat-sealed in the form of, for example, a side seal type, a two-sided seal type, a three-sided seal type, a four-sided seal type, an envelope seal type, a gusset seal type, a pleated seal type, a flat-bottom seal type, a square-bottom seal type, a gusset type, or other heat-seal types. The packaging material of the present invention can take various forms depending on the contents, usage environment, and usage form. It is also possible to make bags in various shapes such as self-standing packaging materials (standing pouches), tube types, and sachets (small bags). As for the heat-sealing method, known methods such as bar seals, rotary roll seals, belt seals, impulse seals, high-frequency seals, and ultrasonic seals can be used.

[0300] Furthermore, after the packaging material of the present invention is made into a bag, an opening start section such as a V-notch or an I-notch may be provided as needed.

[0301] Products using the packaging material of the present invention are manufactured by filling the packaging material with contents through its opening and then heat-sealing the opening. Examples of contents that can be filled include, for example, food products such as rice crackers, bean snacks, nuts, biscuits / cookies, wafers, marshmallows, pies, semi-baked cakes, candies, snack foods, staples such as bread, instant noodles, dried noodles, pasta, aseptically packaged rice, rice porridge, packaged mochi, and cereal foods, processed agricultural products such as pickles, boiled beans, natto, miso, frozen tofu, tofu, enoki mushrooms, konjac, processed wild vegetables, jams, peanut butter, salads, frozen vegetables, and processed potato products, processed livestock products such as ham, bacon, sausages, processed chicken products, and corned beef, and fish meat products. Examples of processed seafood products include sausages, processed seafood products, fish cakes, seaweed, preserved foods, dried bonito flakes, salted seafood, smoked salmon, spicy cod roe, and other processed seafood products; fruits such as peaches, oranges, pineapples, apples, pears, and cherries; vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes; frozen and chilled prepared foods such as hamburgers, meatballs, fried seafood, dumplings, and croquettes; dairy products such as butter, margarine, cheese, cream, instant creamy powder, and infant formula; liquid seasonings; retort curry; and pet food.

[0302] Furthermore, as a non-food product, it can be used as a packaging material for various items such as cigarettes, disposable hand warmers, pharmaceuticals such as intravenous fluid packs, liquid laundry detergent, liquid dish soap, liquid bath detergent, liquid bath soap, liquid shampoo, liquid conditioner, cosmetics such as lotions and emulsions, vacuum insulation materials, and batteries.

[0303] The laminate using the sealant film of the present invention and the retort food packaging material using the laminate can be suitably used for packaging foods that require processing under high temperature hot water conditions such as boiling and retort sterilization, and can be suitably applied to various retort food packaging applications such as curry, stew, soup, cooking sauce, and pet food. [Examples]

[0304] Next, the present invention will be described in more detail with reference to examples and comparative examples. Hereinafter, unless otherwise specified, "parts" and "%" refer to mass.

[0305] (Example 1) Resin mixtures for each layer were prepared using the following resins as the resin components for the base layer, intermediate layer, and sealing layer. The resin mixtures for each layer were supplied to three extruders, and the sealant film was co-extruded from a T-die at an extrusion temperature of 250°C so that the layer ratio of the base layer / intermediate layer / sealing layer was 17 / 66 / 17. The mixture was then cooled with a water-cooled metal cooling roll at 40°C to form a sealant film with a total thickness of 50 μm. Base layer: Linear low-density polyethylene (density 0.941 g / cm³) 3 84 parts by mass of ethylene-α-olefin copolymer (density 0.885 g / cm³) (hereinafter referred to as LLDPE), and ethylene-α-olefin copolymer (density 0.885 g / cm³). 3 A mixture of 15 parts by mass of MFR 1.2 g / 10 min and 1 part by mass of an antiblocking agent. Intermediate layer: A mixture of 85 parts by mass of LLDPE and 15 parts by mass of ethylene-α-olefin copolymer. Seal layer: 30 parts by mass of LLDPE and high-density polyethylene (density 0.961 g / cm³). 3 A mixture of 68 parts by mass of MFR 7.5 g / 10 min (hereinafter referred to as HDPE), 1 part by mass of antiblocking agent, and 1 part by mass of slip agent / antiblocking agent.

[0306] (Examples 2-16) Sealant films of Examples 2 to 16 were obtained in the same manner as in Example 1, except that the film composition was changed as shown in Tables 1, 2, and 3.

[0307] (Comparative Examples 1-4) The sealant films of Comparative Examples 1 to 4 were obtained in the same manner as in Example 1, except that the film composition was changed as shown in Table 3.

[0308] [Impact Resistance] Test specimens were prepared by allowing the sealant films obtained in the examples and comparative examples to stand for 4 hours in a constant temperature room adjusted to 0°C and -10°C. For each test specimen, the impact strength was measured using the film impact method with a BU-302 film impact tester manufactured by Tester Industries, using a 1.0-inch head attached to the tip of a pendulum. ○: Impact strength of 0.60 (J) or higher ×: Impact strength is less than 0.60 (J)

[0309] <Making Laminating Film (1)> In the sealant films obtained in Examples 1-6, 11-16, and Comparative Examples 1-2, a biaxially oriented polyamide (ONy) film (25 μm thick) was bonded to the surface of the substrate layer by dry lamination in the form of ONy film / adhesive layer / sealant film. The laminate films were then aged at 40°C for 72 hours to obtain evaluation laminate films. For the dry lamination adhesive forming the adhesive layer, a two-component curing adhesive manufactured by DIC Corporation (polyester-based adhesive "DIC Dry LX530" and curing agent "DIC Dry KO-55") was used.

[0310] <Making Laminating Film (2)> In Example 7, a biaxially oriented polyethylene terephthalate (PET) film (12 μm thick), aluminum foil (7 μm thick), and PET film were bonded to the surface of the substrate layer of the sealant film obtained in Example 7 by dry lamination, in the order of PET film / adhesive layer / aluminum foil / adhesive layer / PET film / adhesive layer / sealant film. The laminate film was then aged at 40°C for 72 hours to obtain an evaluation laminate film. In this process, a two-component curing adhesive manufactured by DIC Corporation (polyester-based adhesive "DIC Dry LX530" and curing agent "DIC Dry KO-55") was used as the dry lamination adhesive for the adhesive layer.

[0311] <Making Laminating Film (3)> In Example 8, an aluminum-deposited PET film (12 μm thick) and a PET film were bonded to the surface of the substrate layer of the sealant film obtained above by dry lamination in the following order: aluminum-deposited PET film / adhesive layer / PET film / adhesive layer / sealant film. The laminate film was then aged at 40°C for 72 hours to obtain an evaluation laminate film. The aluminum-deposited PET film and the PET film were bonded so that the vapor-deposited layer of the aluminum-deposited PET film and the PET film were in contact. In this case, a two-component curing adhesive manufactured by DIC Corporation (polyester-based adhesive "DIC Dry LX530" and curing agent "DIC Dry KO-55") was used as the dry lamination adhesive for the adhesive layer.

[0312] <Making Laminating Film (4)> In the above Examples 9 and 10, a film with 20 nm of aluminum oxide (hereinafter abbreviated as AlOx) deposited on the surface of the substrate layer of the sealant film was obtained. This film (hereinafter abbreviated as AlOxPET film) (thickness 12 μm) and the PET film were bonded together by dry lamination in the following order: AlOxPET / adhesive layer / PET film / adhesive layer / sealant film. The layers were then aged at 40°C for 72 hours to obtain a laminate film for evaluation. The AlOxPET film and the PET film were bonded together so that the deposited layer of the AlOxPET film and the PET film were in contact. For this dry lamination, a two-component curing adhesive manufactured by DIC Corporation (polyester-based adhesive "DIC Dry LX530" and curing agent "DIC Dry KO-55") was used as the adhesive for the bonding layer.

[0313] [Retort food suitability assessment] From the obtained laminate film, a 22cm x 18cm film was cut out. The film was folded in half so that the sealing layers overlapped, and one vertical and one horizontal edge were heat-sealed 1cm from the edge at 160°C, 0.2MPa, and 1 second. 240mL of water was added, and the opening was sealed using the same heat-sealing conditions to create a three-sided bag. The bag was then heat-treated at 125°C for 30 minutes using a high-temperature, high-pressure cooking sterilization apparatus. After heat sterilization, a sample of the three-sided bag was visually inspected to check for any melting of the film. ○: No film melting ×: Film melting occurs.

[0314] The results obtained above are shown in Tables 1-3.

[0315] [Table 1]

[0316] [Table 2]

[0317] [Table 3]

[0318] The abbreviations used in Tables 1-3 are as follows: LLDPE(1): Linear low-density polyethylene (density 0.941 g / cm³) 3 , MFR1.2g / 10min) LLDPE(2): Linear low-density polyethylene (density 0.941 g / cm³) 3 (MFR 4.0g / 10 mins) Ethylene-α-olefin copolymer: Ethylene-α-olefin copolymer (density 0.885 g / cm³) 3 , MFR1.2g / 10min) HDPE(1): High-density polyethylene (density 0.961 g / cm³) 3 , MFR7.5g / 10min) HDPE(2): High-density polyethylene (density 0.956 g / cm³) 3 (MFR 1.1g / 10 min) Recovered material: Fluff obtained by crushing the edges of films with the same resin composition as each example.

[0319] As is clear from Tables 1 to 3 above, the sealant films of the present invention in Examples 1 to 16 exhibited excellent impact resistance even under freezing conditions below 0°C, and the laminates using these sealant films exhibited suitable retort resistance even at a retort sterilization temperature of 125°C. On the other hand, the sealant films and laminates of Comparative Examples 1 to 4 were unable to possess both suitable impact resistance and retort resistance.

Claims

1. It comprises a base layer, one or more intermediate layers, and a sealing layer in this order. The aforementioned base layer contains ethylene resin in an amount of 65% by mass or more and 100% by mass or less of the resin components contained in the base layer. At least one of the one or more intermediate layers comprises a linear low-density polyethylene and an ethylene-α-olefin copolymer. The content of the ethylene-α-olefin copolymer in the at least one intermediate layer is 5% by mass or more and 20% by mass or less, relative to the total amount of resin components contained in the intermediate layer. The density of the ethylene-α-olefin copolymer in the at least one intermediate layer is 0.850 g / cm³ or more and less than 0.900 g / cm³. The sealing layer comprises linear low-density polyethylene and high-density polyethylene with an MFR of 3.0 g / 10 min or more. The content of the linear low-density polyethylene in the resin component contained in the sealing layer is 30 to 60% by mass. The content of the high-density polyethylene in the resin component contained in the sealing layer is 30 to 70% by mass. The MFR of the resin component constituting the base layer and the resin component constituting the at least one intermediate layer is less than 3.0 g / 10 min (190°C, 21.18 N), High-density polyethylene is contained in the sealant film in an amount of 8.5 to 19.0% by mass of the total amount of resin components contained in the entire film. The thickness ratio of the base layer to the total thickness of the sealant film is 10 to 45%, the total thickness ratio of the one or more intermediate layers is 40 to 80%, and the thickness ratio of the seal layer is 5 to 40%. Sealant film.

2. The sealant film according to claim 1, wherein the ethylene-α-olefin copolymer is contained in an amount of 5 to 30% by mass of the total amount of resin components contained in the entire sealant film.

3. The sealant film according to claim 1, wherein the base layer contains linear low-density polyethylene, and the MFR of the linear low-density polyethylene is less than 3.0 g / 10 min (190°C, 21.18 N).

4. The average density of the resin components constituting the aforementioned at least one intermediate layer is 0.9333 g / cm³. ３ A sealant film according to claim 1, wherein the value is less than [value missing].

5. The content of the linear low-density polyethylene in the resin component contained in the sealing layer is 30 to 50% by mass, The content of the high-density polyethylene in the resin component contained in the sealing layer is 48 to 68% by mass. The sealant film according to claim 1.

6. A laminate comprising a sealant film according to any one of claims 1 to 5 as the sealant.

7. A packaging material containing the laminate described in claim 6.

8. The packaging material according to claim 7, for use in retort packaging of food products.

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