Polyurethane dispersions, gas barrier coating materials, and laminates

Abstract

The polyurethane dispersion is an aqueous dispersion of a polyurethane resin. The polyurethane resin is a reaction product of an isocyanate group-terminated prepolymer and a chain extender. The isocyanate group-terminated prepolymer contains a reaction product of a polyisocyanate component containing xylylene diisocyanate and an active hydrogen group-containing component containing a short-chain diol having 2 to 6 carbon atoms and an active hydrogen group-containing compound containing a hydrophilic group. The chain extender contains ethylenediamine. The proportion of ethylenediamine is 25 mol% or more relative to the total amount of the chain extender.

Description

Technical Field

[0001] This invention relates to polyurethane dispersions, gas barrier coating materials, and laminates. Background Technology

[0002] Previously, it was known to impart gas barrier properties to a substrate by forming a resin layer containing polyurethane resin (hereinafter referred to as the polyurethane layer) on the surface of the substrate.

[0003] As a method for manufacturing polyurethane resin, the following method is proposed. First, a polyurethane prepolymer containing carboxylic acid groups is synthesized by reacting hydrogenated XDI, dimethylolpropionic acid, and ethylene glycol. Next, the carboxylic acid groups are neutralized using triethylamine. Then, the polyurethane prepolymer containing carboxylic acid groups is subjected to a chain extension reaction using ethylenediamine. Additionally, a gas barrier film obtained by laminating polyurethane resin onto the surface of a biaxially stretched polypropylene film is proposed (see, for example, Patent Document 1 (Manufacturing Example 8)).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2001-98047 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] On the other hand, heat resistance is sometimes required for polyurethane layers. However, the heat resistance of the polyurethane resins mentioned above is insufficient. In addition, excellent storage stability is required for polyurethane resins.

[0009] The present invention relates to a polyurethane dispersion and a gas barrier coating material capable of forming a polyurethane layer with excellent gas barrier properties, heat resistance and storage stability, as well as a laminate having a polyurethane layer.

[0010] Methods for solving problems

[0011] The present invention [1] includes a polyurethane dispersion, which is an aqueous dispersion of polyurethane resin. The polyurethane resin is a reaction product of isocyanate-terminated prepolymer and chain extender. The isocyanate-terminated prepolymer is a reaction product of polyisocyanate component and active hydrogen group component. The polyisocyanate component includes phenylene diisocyanate. The active hydrogen group component includes short-chain diol with 2 to 6 carbon atoms and active hydrogen group compound containing hydrophilic group. The chain extender includes ethylenediamine, and the proportion of ethylenediamine relative to the total amount of the chain extender is 25 mol% or more.

[0012] The present invention [2] includes the polyurethane dispersion described in [1] above, wherein the aforementioned active hydrogen group component further comprises an alcohol of 3 or more moles, and the proportion of the aforementioned alcohol of 3 or more moles relative to the total amount of the aforementioned active hydrogen group component is more than 1 mol% and less than 15 mol%.

[0013] The present invention [3] includes the polyurethane dispersion described in [1] or [2] above, wherein the aforementioned polyisocyanate component further includes methylene bis(cyclohexyl isocyanate), and the content of methylene bis(cyclohexyl isocyanate) relative to the total amount of the aforementioned polyisocyanate component is more than 1 mol% and less than 30 mol%.

[0014] The present invention [4] includes the polyurethane dispersion described in any one of [1] to [3] above, wherein the coefficient of thermal expansion of the aforementioned polyurethane resin is 2000 × 10⁻⁶. -6 K -1 the following.

[0015] The present invention [5] includes any one of the polyurethane dispersions described in [1] to [4] above, and further comprises at least one selected from the group consisting of epoxy silanes, water-dispersible polyisocyanates and carbodiimides.

[0016] The present invention [6] includes the polyurethane dispersion described above [5], wherein the content of carbodiimide groups in the aforementioned carbodiimide compound is more than 0.3 moles and less than 3.0 moles relative to 1 mole of carboxyl groups in the aforementioned polyurethane resin.

[0017] The present invention [7] includes a gas barrier coating material comprising the polyurethane dispersion described in any one of [1] to [6] above.

[0018] The present invention [8] includes a laminate having a substrate and a polyurethane layer disposed on the surface of the substrate, wherein the polyurethane layer is a dried product of the gas barrier coating material described above [7].

[0019] Invention Effects

[0020] In the polyurethane dispersion of the present invention, the polyisocyanate component includes phenylene diisocyanate, and the chain extender includes ethylenediamine in a specified proportion.

[0021] Therefore, the polyurethane dispersion of the present invention comprises a polyurethane resin with excellent gas barrier properties, heat resistance and storage stability.

[0022] As a result, the polyurethane dispersion and gas barrier coating material of the present invention can form a polyurethane layer with excellent gas barrier properties, heat resistance and storage stability.

[0023] In the laminate of the present invention, the polyurethane layer is the dried product of the gas barrier coating material described above.

[0024] Therefore, the laminate of the present invention has excellent gas barrier properties and heat resistance. Attached Figure Description

[0025] [ Figure 1 ] Figure 1 A schematic structural diagram illustrating one embodiment of a laminate using the polyurethane dispersion of the present invention.

[0026] [ Figure 2 ] Figure 2 A graph showing the relationship between the coefficient of thermal expansion and the ratio of trimethylolpropane in Examples 1, 5-7, Comparative Examples 2 and 4-6 is provided.

[0027] [ Figure 3 ] Figure 3 A graph showing the relationship between the coefficient of thermal expansion and the ratio of methylene bis(cyclohexyl isocyanate) in Examples 1, 8-11, Comparative Examples 2 and 7-10 is provided. Detailed Implementation

[0028] The polyurethane dispersion of the present invention is an aqueous dispersion of polyurethane resin.

[0029] Examples of polyurethane resins include gas-barrier polyurethane resins. It should be noted that gas barrier properties refer to the property of reducing oxygen permeability.

[0030] Gas barrier polyurethane resins contain reaction products obtained by reacting a polyisocyanate component with a component containing active hydrogen groups.

[0031] More specifically, gas-barrier polyurethane resin is obtained through the reaction of isocyanate-terminated prepolymers with chain extenders. The isocyanate-terminated prepolymers are obtained through the reaction of a polyisocyanate component with a component containing active hydrogen groups. That is, the isocyanate-terminated prepolymer is a primary reaction product of the polyisocyanate component and the component containing active hydrogen groups. The gas-barrier polyurethane resin is a secondary reaction product of the isocyanate-terminated prepolymer and the chain extender.

[0032] In the preparation of polyurethane dispersions, for example, firstly, isocyanate-terminated prepolymers are synthesized. Isocyanate-terminated prepolymers are polyurethane prepolymers having two or more free isocyanate groups at the molecular ends. Isocyanate-terminated prepolymers are obtained, as described above, by reacting a polyisocyanate component with a component containing active hydrogen groups.

[0033] Polyisocyanate components include phenylene diisocyanate (XDI) as an essential component.

[0034] Examples of phenylene diisocyanates include, for example, phenylene diisocyanate monomers (XDI monomers) and phenylene diisocyanate derivatives (XDI derivatives).

[0035] Examples of phenylene diisocyanate monomers include 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, and 1,4-phenylene diisocyanate. These phenylene diisocyanate monomers can be used alone or in combination of two or more. 1,3-phenylene diisocyanate and 1,4-phenylene diisocyanate are preferred monomers, and 1,3-phenylene diisocyanate is more preferred.

[0036] Examples of phenylene diisocyanate derivatives include modified forms obtained by modifying the aforementioned phenylene diisocyanate monomers using known methods. More specifically, examples of phenylene diisocyanate derivatives include polymers, urea-formaldehyde modified forms, polyol modified forms, biuret modified forms, urea modified forms, oxadiazine trione modified forms, and carbodiimide modified forms. These phenylene diisocyanate derivatives can be used alone or in combination of two or more.

[0037] These phthalene diisocyanates can be used alone or in combination of two or more. As phthalene diisocyanates, phthalene diisocyanate monomers are preferred.

[0038] In addition, the polyisocyanate component may include other polyisocyanates as optional ingredients. Other polyisocyanates are those that do not include phthalene diisocyanate.

[0039] Other polyisocyanates include those commonly used in industry. More specifically, examples include aromatic polyisocyanates, aromatic aliphatic polyisocyanates (excluding phenylene diisocyanate), aliphatic polyisocyanates, and alicyclic polyisocyanates. Additionally, other polyisocyanates include derivatives of the same class as those described above. Other polyisocyanates can be used alone or in combination of two or more.

[0040] As other polyisocyanates, alicyclic polyisocyanates are preferred. Examples of alicyclic polyisocyanates include, for example, bis(isocyanatomethyl)cyclohexane (H6XDI) and methylene bis(cyclohexyl)isocyanate (H... 12 MDI and isophorone diisocyanate (IPDI). These alicyclic polyisocyanates can be used alone or in combination of two or more.

[0041] As alicyclic polyisocyanates, preferred examples include bis(isocyanate methyl)cyclohexane (H6XDI) and methylene bis(cyclohexyl)isocyanate (H6XDI). 12MDI), more preferably methylene bis(cyclohexyl isocyanate) (H 12 MDI).

[0042] It should be noted that when the polyisocyanate component contains other polyisocyanates, the ratio of phenylene diisocyanate to other polyisocyanates can be suitably set within a range that does not impair the excellent effects of the present invention.

[0043] For example, when using phenylene diisocyanate and alicyclic polyisocyanate, the phenylene diisocyanate content, relative to their total molarity, is, for example, 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. Furthermore, relative to their total molarity, the phenylene diisocyanate content, for example, is 99.9 mol% or less, preferably 99 mol% or less, more preferably 95 mol% or less, and even more preferably 90 mol% or less.

[0044] Furthermore, when using phenylene diisocyanate and alicyclic polyisocyanate, the alicyclic polyisocyanate content, relative to their total molarity, is, for example, 0.1 mol% or more, preferably 1 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more. Additionally, relative to their total molarity, it is, for example, 50 mol% or less, preferably 40 mol% or less, more preferably 30 mol% or less, and even more preferably 20 mol% or less.

[0045] Especially when the polyisocyanate component includes phenylene diisocyanate and the chain extender (described later) includes ethylenediamine, alicyclic polyisocyanates contribute to heat resistance and storage stability. Therefore, when the polyisocyanate component includes phenylene diisocyanate and the chain extender (described later) includes ethylenediamine, if the proportion of alicyclic polyisocyanate is higher than the aforementioned lower limit, a polyurethane resin with superior heat resistance can be obtained. Furthermore, therefore, when the polyisocyanate component includes phenylene diisocyanate and the chain extender (described later) includes ethylenediamine, if the proportion of alicyclic polyisocyanate is lower than the aforementioned upper limit, a polyurethane resin with superior storage stability can be obtained.

[0046] Polyols are an example of components containing active hydrogen groups. Essential components of polyols include short-chain diols with 2 to 6 carbon atoms and compounds containing hydrophilic groups and active hydrogen groups.

[0047] Short-chain diols with 2 to 6 carbon atoms are organic compounds with two hydroxyl groups and 2 to 6 carbon atoms. It should be noted that the molecular weight of short-chain diols is between 50 and 650. When short-chain diols have a molecular weight distribution, the molecular weight is expressed as the number-average molecular weight converted to polystyrene by GPC determination.

[0048] Examples of short-chain diols include alkane diols with 2 to 6 carbon atoms, ether diols with 2 to 6 carbon atoms, and olefin diols with 2 to 6 carbon atoms.

[0049] Examples of alkane diols with 2 to 6 carbon atoms include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentanediol, 3-methyl-1,5-pentanediol, 1,3-cyclohexanediol, and 1,4-cyclohexanediol. Examples of ether diols with 2 to 6 carbon atoms include diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of olefin diols with 2 to 6 carbon atoms include 1,4-dihydroxy-2-butene. These short-chain diols can be used alone or in combination of two or more. From the viewpoint of gas barrier properties, alkane diols with 2 to 6 carbon atoms are preferred as short-chain diols, and ethylene glycol is more preferred.

[0050] The proportion of short-chain diols with 2 to 6 carbon atoms is, for example, 10 parts by mass or more, preferably 30 parts by mass or more, more preferably 50 parts by mass or more, for example, 90 parts by mass or less, preferably 80 parts by mass or less, and more preferably 70 parts by mass or less, relative to the total amount of components containing active hydrogen groups of 100 parts by mass.

[0051] Compounds containing hydrophilic groups and active hydrogen groups are compounds containing both hydrophilic groups and active hydrogen groups. It should be noted that, for example, hydroxyl and amino groups can be considered as active hydrogen groups.

[0052] Furthermore, examples of hydrophilic groups include nonionic groups and ionic groups. More specifically, examples of compounds containing active hydrogen groups and containing hydrophilic groups include compounds containing active hydrogen groups and compounds containing active hydrogen groups and ionic groups.

[0053] Compounds containing nonionic groups and active hydrogen groups are compounds that possess both one or more nonionic groups and two or more active hydrogen groups. Examples of nonionic groups include polyoxyethylene. Examples of compounds containing nonionic groups and active hydrogen groups include polyoxyethylene glycol, single-terminated polyoxyethylene glycol, and polyols containing polyoxyethylene side chains.

[0054] Examples of compounds containing ionic groups and active hydrogen groups include compounds containing anionic groups and compounds containing cationic groups. Compounds containing anionic groups and active hydrogen groups are compounds possessing one or more anionic groups and two or more active hydrogen groups. Examples of anionic groups include carboxyl groups (carboxylic acid groups) and sulfonyl groups (sulfonic acid groups). Compounds containing cationic groups and active hydrogen groups are compounds possessing one or more cationic groups and two or more active hydrogen groups. Examples of cationic groups include quaternary ammonium groups.

[0055] These compounds containing hydrophilic groups and active hydrogen groups can be used alone or in combination of two or more. Preferably, compounds containing anionic groups are also considered as compounds containing hydrophilic groups and active hydrogen groups.

[0056] Among compounds containing anionic groups and active hydrogen groups, examples of anionic groups include carboxyl groups (carboxylic acid groups) and sulfonyl groups (sulfonic acid groups).

[0057] From the viewpoint of gas barrier properties and water resistance, a carboxyl group is preferably an anionic group. Among compounds containing anionic groups and active hydrogen groups, hydroxyl and amino groups are examples of active hydrogen groups, with a hydroxyl group being preferred.

[0058] That is, as a compound containing anionic groups and active hydrogen groups, an organic compound having both a carboxyl group and two hydroxyl groups is preferred.

[0059] Examples of organic compounds possessing both a carboxyl group and two hydroxyl groups include, for example, polyols containing a carboxyl group. Examples of polyols containing a carboxyl group include polyhydroxyalkanoic acids. Examples of polyhydroxyalkanoic acids include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid (also known as dimethylolpropionic acid), 2,2-dimethylolbutyric acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvalerate. These organic compounds possessing both a carboxyl group and two hydroxyl groups can be used alone or in combination of two or more. 2,2-dimethylolpropionic acid is preferably an example of an organic compound possessing both a carboxyl group and two hydroxyl groups.

[0060] The proportion of the active hydrogen group-containing compound containing hydrophilic groups is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, for example, 50 parts by mass or less, and preferably 40 parts by mass or less, relative to the total amount of 100 parts by mass of the active hydrogen group component.

[0061] In addition, the polyol component may also contain other low molecular weight polyols as optional ingredients. Other low molecular weight polyols are low molecular weight polyols that do not include short-chain diols with 2 to 6 carbon atoms, and compounds containing hydrophilic groups or active hydrogen groups. Low molecular weight polyols are organic compounds with a lower molecular weight and having two or more hydroxyl groups in their molecules. It should be noted that the molecular weight of the low molecular weight polyol is 50 or more and 650 or less, preferably 500 or less. Examples of other low molecular weight polyols include, for example, diols with 7 or more carbon atoms, and low molecular weight polyols with 3 or more carbon atoms.

[0062] Examples of diols having 7 or more carbon atoms include alkane (7-20 carbon atoms)-1,2-diol, 2,6-dimethyl-1-octene-3,8-diol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, hydrogenated bisphenol A, and bisphenol A. These diols having 7 or more carbon atoms can be used alone or in combination of two or more.

[0063] Examples of low molecular weight polyols with three or more components include trihydric and tetrahydric alcohols. Examples of trihydric alcohols include glycerol, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, trimethylolpropane, and 2,2-bis(hydroxymethyl)-3-butanol. Examples of tetrahydric alcohols include tetramethylolmethane (pentaerythritol) and diglycerol. These low molecular weight polyols with three or more components can be used alone or in combination of two or more.

[0064] In addition, other low molecular weight polyols include polyether polyols with a number average molecular weight of 650 or less, polyester polyols with a number average molecular weight of 650 or less, and polycarbonate polyols with a number average molecular weight of 650 or less.

[0065] Other low molecular weight polyols may be used alone or in combination of two or more. From the viewpoint of water resistance and water dispersion stability, low molecular weight polyols with three or more components are preferred, trihydric alcohols are more preferred, and trimethylolpropane is particularly preferred.

[0066] When the active hydrogen group component contains an alcohol with three or more nucleotides, the proportion of the alcohol with three or more nucleotides relative to the total amount of the active hydrogen group component is, for example, 0.1 mol% or more, preferably 1 mol% or more, more preferably 3 mol% or more, for example, 30 mol% or less, preferably 15 mol% or less, more preferably 10 mol% or less.

[0067] Especially when the polyisocyanate component includes phenylene diisocyanate and the chain extender (described later) includes ethylenediamine, alcohols with three or more tertiary components contribute to heat resistance, storage stability, and ease of manufacture. Therefore, when the polyisocyanate component includes phenylene diisocyanate and the chain extender (described later) includes ethylenediamine, if the proportion of alcohols with three or more tertiary components is higher than the aforementioned lower limit, a polyurethane resin with superior heat resistance and storage stability can be obtained. Furthermore, when the polyisocyanate component includes phenylene diisocyanate and the chain extender (described later) includes ethylenediamine, if the proportion of alcohols with three or more tertiary components is lower than the aforementioned upper limit, a polyurethane resin with superior ease of manufacture can be obtained.

[0068] It should be noted that the molar ratio of alcohols with 3 or more hydroxyl groups in the active hydrogen group component can be calculated by known methods based on hydroxyl equivalent (molecular weight / number of hydroxyl groups) and complexation amount.

[0069] In addition, when the active hydrogen group component contains other low molecular weight polyols, the proportion of other low molecular weight polyols relative to the total amount of the active hydrogen group component (100 parts by mass) is, for example, 0.2 parts by mass or more, preferably 1 part by mass or more, more preferably 2 parts by mass or more, for example, 20 parts by mass or less, preferably 10 parts by mass or less, more preferably 8 parts by mass or less.

[0070] Furthermore, regarding the proportion of short-chain diols with 2 to 6 carbon atoms used in combination with other low molecular weight polyols, relative to their total amount of 100 parts by mass, the other low molecular weight polyols are, for example, 2 parts by mass or more, preferably 5 parts by mass or more, for example, 20 parts by mass or less, preferably 15 parts by mass or less, and more preferably 10 parts by mass or less.

[0071] In addition, relative to the total amount of short-chain diols with 2 to 6 carbon atoms and other low molecular weight polyols of 100 parts by mass, the compound containing hydrophilic groups and active hydrogen groups is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 40 parts by mass or more, for example, 90 parts by mass or less, preferably 80 parts by mass or less, more preferably 70 parts by mass or less.

[0072] If the proportion of other low molecular weight polyols is within the above range, excellent dispersibility can be ensured.

[0073] In addition, the polyol component may also contain high molecular weight polyols as an optional ingredient. High molecular weight polyols are organic compounds (polymers) with a relatively high molecular weight and having two or more hydroxyl groups in their molecules. It should be noted that the number average molecular weight of high molecular weight polyols is, for example, higher than 650, and for example, lower than 20,000. Examples of high molecular weight polyols include, for example, polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These high molecular weight polyols can be used alone or in combination of two or more.

[0074] However, high molecular weight polyols can sometimes reduce the gas barrier properties of polyurethane resins (described later). Therefore, the polyol component preferably does not contain high molecular weight polyols.

[0075] That is, the polyol component preferably consists of short-chain diols with 2 to 6 carbon atoms, low molecular weight polyols with 3 or more carbon atoms, and compounds containing hydrophilic groups and active hydrogen groups, or consists of short-chain diols with 2 to 6 carbon atoms and compounds containing hydrophilic groups and active hydrogen groups. More preferably, the polyol component consists of short-chain diols with 2 to 6 carbon atoms, low molecular weight polyols with 3 or more carbon atoms, and compounds containing anionic groups and active hydrogen groups, or consists of short-chain diols with 2 to 6 carbon atoms and compounds containing anionic groups and active hydrogen groups.

[0076] Isocyanate-terminated prepolymers are obtained by reacting the above components in a specified equivalence ratio. In the synthesis of isocyanate-terminated prepolymers, the equivalence ratio is the ratio of isocyanate groups to active hydrogen groups (hydroxyl groups) (isocyanate groups / active hydrogen groups).

[0077] The equivalence ratio (isocyanate group / active hydrogen group) is, for example, higher than 1, preferably 1.1 or higher. In addition, the equivalence ratio (isocyanate group / active hydrogen group) is, for example, 20 or less, preferably 10 or less.

[0078] In addition, known polymerization methods can be used in the synthesis of isocyanate-terminated prepolymers.

[0079] Examples of polymerization methods include bulk polymerization and solution polymerization.

[0080] From the perspective of adjusting reactivity, solution polymerization is preferred as a polymerization method.

[0081] In bulk polymerization, for example, the above-mentioned components are combined and reacted under a nitrogen atmosphere. The reaction temperature is, for example, 75–85°C. The reaction time is, for example, 1–20 hours.

[0082] In solution polymerization, for example, the above-mentioned components are combined and reacted in an organic solvent under a nitrogen atmosphere. The reaction temperature is, for example, 20–80°C. The reaction time is, for example, 1–20 hours.

[0083] Solvents that are inactive with respect to isocyanate groups can be cited as examples of organic solvents. Examples of organic solvents include acetone, methyl ethyl ketone, ethyl acetate, tetrahydrofuran, and acetonitrile. These organic solvents can be used alone or in combination of two or more.

[0084] In addition, a catalyst may be added during the above polymerization process as needed. Examples of catalysts include amine catalysts and organometallic catalysts. These catalysts can be used alone or in combination of two or more. It should be noted that the amount of catalyst added can be appropriately determined according to the purpose and application.

[0085] Furthermore, in this method, the polymerization is terminated, for example, when the concentration of isocyanate groups in the reaction product reaches the range described later. Additionally, in this method, unreacted polyisocyanate components can be removed using known removal methods. Examples of removal methods include distillation and extraction.

[0086] Thus, isocyanate-terminated prepolymers can be obtained.

[0087] The isocyanate group concentration of the isocyanate-terminated prepolymer is, for example, 4% by mass or more, preferably 5% by mass or more, and more preferably 6% by mass or more. Furthermore, the isocyanate group concentration of the isocyanate-terminated prepolymer is, for example, 25% by mass or less, preferably 20% by mass or less, more preferably 17% by mass or less, and even more preferably 15% by mass or less.

[0088] Furthermore, the average number of functional groups of the isocyanate group is, for example, 1.5 or more, preferably 1.9 or more, and more preferably 2.0 or more. Additionally, the average number of functional groups of the isocyanate group is, for example, 3.0 or less, preferably 2.5 or less.

[0089] Furthermore, when the isocyanate-terminated prepolymer contains anionic groups, a neutralizing agent can be added to the isocyanate-terminated prepolymer to neutralize it, forming a salt of the anionic group. Commonly used bases can be cited as neutralizing agents. Specifically, organic and inorganic bases can be cited as bases.

[0090] Examples of organic bases include, for example, tertiary and secondary amines. Examples of tertiary amines include, for example, trialkylamines and alkanolamines. Examples of trialkylamines include, for example, trialkylamines having 1 to 4 carbon atoms. Examples of such trialkylamines include, for example, trimethylamine and triethylamine. Examples of alkanolamines include, for example, dimethylethanolamine, methyldiethanolamine, triethanolamine, and triisopropanolamine. Examples of secondary amines include, for example, heterocyclic amines. Examples of heterocyclic amines include, for example, morpholine. These organic bases can be used alone or in combination of two or more.

[0091] Examples of inorganic bases include, for example, ammonia, alkali metal hydroxides, alkaline earth metal hydroxides, and alkali metal carbonates. Examples of alkali metal hydroxides include, for example, lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of alkaline earth metal hydroxides include, for example, magnesium hydroxide and calcium hydroxide. Examples of alkali metal carbonates include, for example, sodium carbonate and potassium carbonate. These inorganic bases can be used alone or in combination of two or more.

[0092] These neutralizing agents can be used alone or in combination of two or more. As neutralizing agents, organic bases are preferred, tertiary amines are more preferred, trialkylamines are even more preferred, and triethylamines are particularly preferred.

[0093] The amount of neutralizing agent added relative to the equivalent of 1 anionic group is, for example, 0.4 equivalents or more, preferably 0.6 equivalents or more. Furthermore, the amount of neutralizing agent added relative to the equivalent of 1 anionic group is, for example, 1.2 equivalents or less, preferably 1.0 equivalents or less.

[0094] Next, in this method, the isocyanate-terminated prepolymer (the primary reaction product) is reacted with a chain extender to obtain a gas-barrier polyurethane resin (the secondary reaction product).

[0095] For example, a polyurethane dispersion can be obtained by reacting an isocyanate-terminated prepolymer with a chain extender in water.

[0096] Chain extenders are organic compounds with multiple active hydrogen groups that enable isocyanate-terminated prepolymers to undergo chain extension reactions.

[0097] Chain extenders contain ethylenediamine as an essential component.

[0098] When the chain extender contains ethylenediamine and the polyisocyanate component contains phenylene diisocyanate, polyurethane resins with excellent gas barrier properties, heat resistance and storage stability can be obtained due to their excellent crystallinity.

[0099] In addition, the chain extender may include other chain extenders as optional components. Other chain extenders are those that do not contain ethylenediamine. Examples of other chain extenders include, for instance, polyamines and amino alcohols.

[0100] Examples of polyamines include, for example, aromatic polyamines, aromatic aliphatic polyamines, alicyclic polyamines, aliphatic polyamines (excluding ethylenediamine), and polyamines containing polyoxyethylene.

[0101] Examples of aromatic polyamines include, for example, 4,4'-diphenylmethane diamine and toluene diamine.

[0102] Examples of aromatic aliphatic polyamines include, for example, 1,3-phenylenediamine and 1,4-phenylenediamine.

[0103] Examples of alicyclic polyamines include, for example, 3-aminomethyl-3,5,5-trimethylcyclohexylamine (also known as isophorone diamine), 4,4'-dicyclohexylmethane diamine, 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, 1,4-cyclohexane diamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis-(4-aminocyclohexyl)methane, diaminocyclohexane, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 1,3-bis(aminomethyl)cyclohexane, and 1,4-bis(aminomethyl)cyclohexane.

[0104] Examples of aliphatic polyamines include, for example, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, hydrazine, hydrazine hydrate, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1,2-diaminoethane, 1,2-diaminopropane, and 1,3-diaminopentane.

[0105] Examples of polyamines containing polyoxyethylene ethers include, for example, polyoxyalkylene ether diamines. More specifically, examples include PEG#1000 diamine (manufactured by Nippon Yushi), JEFFAMINE ED-2003 (manufactured by Huntsman Corporation), JEFFAMINE EDR-148 (manufactured by Huntsman Corporation), and JEFFAMINE XTJ-512 (manufactured by Huntsman Corporation).

[0106] Examples of amino alcohols include 2-((2-aminoethyl)amino)ethanol (also known as N-(2-aminoethyl)ethanolamine) and 2-((2-aminoethyl)amino)-1-methylpropanol (also known as N-(2-aminoethyl)isopropanolamine).

[0107] In addition, other chain extenders include alkoxysilyl compounds having a primary amino group, and alkoxysilyl compounds having both primary and secondary amino groups.

[0108] Examples of alkoxysilyl compounds having a primary amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane.

[0109] Examples of alkoxysilyl compounds having primary and secondary amino groups include N-β(aminoethyl)γ-aminopropyltrimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane), N-β(aminoethyl)γ-aminopropyltriethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltriethoxysilane), N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane), and N-β(aminoethyl)γ-aminopropylmethyldiethoxysilane (also known as N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane).

[0110] Other chain extenders can be used alone or in combination of two or more.

[0111] As other chain extenders, amino alcohols are preferred, and 2-((2-aminoethyl)amino)ethanol is more preferred.

[0112] In the chain extender, the content of ethylenediamine relative to the total amount of chain extender is 25 mol% or more, preferably 30 mol% or more, more preferably 50 mol% or more, further preferably 70 mol% or more, more preferably 90 mol% or more, and especially preferably 100 mol%.

[0113] In addition, when the content of ethylenediamine is less than 100 mol%, the remainder is other chain extenders.

[0114] When the ethylenediamine content is within the above range and the polyisocyanate component includes phenylene diisocyanate, polyurethane resins with excellent gas barrier properties, heat resistance and storage stability can be obtained due to their excellent crystallinity.

[0115] It should be noted that polyurethane resins containing ethylenediamine and other chain extenders as chain extenders can be obtained, for example, by adding ethylenediamine and other chain extenders together or sequentially in the chain extension reaction described later.

[0116] Alternatively, for example, a polyurethane resin containing ethylenediamine and other chain extenders can also be obtained by mixing a polyurethane resin obtained by chain extension reaction using ethylenediamine with a polyurethane resin obtained by chain extension reaction using other chain extenders.

[0117] In chain extension reactions, for example, isocyanate-terminated prepolymers and chain extenders are reacted in water.

[0118] More specifically, for example, firstly, the isocyanate-terminated prepolymer is dispersed in water.

[0119] Next, a chain extender is added to the aqueous dispersion of the isocyanate-terminated prepolymer to extend the chain of the isocyanate-terminated prepolymer. There are no particular limitations on the method for dispersing the isocyanate-terminated prepolymer in water. For example, the isocyanate-terminated prepolymer can be added to water while stirring. In this case, the amount of water is 100 to 1000 parts by mass relative to 100 parts by mass of the isocyanate-terminated prepolymer.

[0120] Then, while stirring the water obtained by dispersing the isocyanate-terminated prepolymer, a chain extender is added dropwise to the water. In this case, the equivalence ratio (active hydrogen group / isocyanate group) of the chain extender to the isocyanate groups of the isocyanate-terminated prepolymer is, for example, 0.6 to 1.2. The chain extension reaction is carried out, for example, at room temperature. The time until the reaction is completed is, for example, 0.1 to 10 hours.

[0121] In addition, in this method, to adjust the concentration of the solid component, the organic solvent and / or water can be removed after the reaction is complete. Alternatively, in this method, to adjust the concentration of the solid component, water can be added after the reaction is complete.

[0122] Furthermore, in this method, a solvent can be added to adjust the concentration of the solid component. Examples of solvents include water, methanol, ethanol, propanol, isopropanol, acetone, methyl ethyl ketone, ethyl acetate, tetrahydrofuran, and acetonitrile. These solvents can be used alone or in combination of two or more.

[0123] Thus, polyurethane dispersion (PUD) can be obtained.

[0124] The concentration of the solid component in the polyurethane dispersion is, for example, 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more. Furthermore, the concentration of the solid component in the polyurethane dispersion is, for example, 60% by mass or less, preferably 50% by mass or less, and more preferably 40% by mass or less.

[0125] The pH of the polyurethane dispersion is, for example, 5 or higher, preferably 6 or higher. Furthermore, the pH of the polyurethane dispersion is, for example, 11 or lower, preferably 10 or lower.

[0126] The average particle size of the polyurethane dispersion is, for example, 10 nm or more, preferably 20 nm or more, and more preferably 50 nm or more. Furthermore, the average particle size of the polyurethane dispersion is, for example, 500 nm or less, preferably 300 nm or less, and more preferably 200 nm or less.

[0127] Furthermore, the polyurethane dispersion exhibits a relatively high combined concentration of urethane and urea groups. Increasing both the urethane and urea group concentrations enhances gas barrier properties.

[0128] The combined concentration of urethane groups and urea groups is, for example, 30% by mass or more, preferably 34% by mass or more, and more preferably 38% by mass or more. Furthermore, the combined concentration of urethane groups and urea groups is, for example, 50% by mass or less, preferably 46% by mass or less, and more preferably 42% by mass or less. It should be noted that the combined concentration of urethane groups and urea groups can be calculated from the input ratio of the raw material components.

[0129] In addition, polyurethane dispersions may contain additives.

[0130] Examples of additives include, for instance, fillers, silane coupling agents (excluding epoxy silanes described below), alkoxy silane compounds, thickeners, antioxidants, heat stabilizers, ultraviolet absorbers, plasticizers, antistatic agents, lubricants, antiblocking agents, surfactants, dispersion stabilizers, colorants, pigments, dyes, colloidal silica, inorganic particles, inorganic oxide particles, layered inorganic compounds, leveling agents, nucleating agents, crosslinking agents, and curing agents. These additives can be used alone or in combination of two or more. It should be noted that there are no particular restrictions on the proportions of the additives used, and they can be appropriately set according to the purpose and application.

[0131] In such a polyurethane dispersion, the polyisocyanate component includes phenylene diisocyanate, and the chain extender includes a specified proportion of ethylenediamine.

[0132] Therefore, polyurethane dispersions contain polyurethane resins with excellent gas barrier properties, heat resistance, and storage stability.

[0133] The heat resistance of polyurethane resins can be evaluated, for example, using the coefficient of thermal expansion.

[0134] The coefficient of thermal expansion of polyurethane resin is, for example, 2000 × 10⁻⁶. -6 K -1 The following is preferred: 1500×10 -6 K -1 Hereinafter, 1000×10 is preferred. -6 K -1 The following is a further preferred value: 500×10 -6 K -1 The following is particularly preferred: 100×10 -6 K -1 The following is an explanation. Additionally, the coefficient of thermal expansion of polyurethane resin is typically 1×10⁻⁶. -6 K -1above.

[0135] It should be noted that, for the coefficient of thermal expansion of polyurethane resin, the measurement was performed using a polyurethane resin film, according to the examples described later.

[0136] Furthermore, based on the aforementioned polyurethane dispersion, a polyurethane layer with excellent gas barrier properties, heat resistance, and storage stability can be formed.

[0137] Therefore, the polyurethane dispersions described above are suitable for use as gas barrier coating materials.

[0138] The gas barrier coating material comprises the polyurethane dispersion described above.

[0139] In addition, gas barrier coating materials may contain additives. Examples of additives include, for instance, fillers, silane coupling agents (excluding epoxy silanes described later), alkoxy silane compounds, thickeners, antioxidants, heat stabilizers, UV absorbers, plasticizers, antistatic agents, lubricants, antiblocking agents, surfactants, dispersion stabilizers, colorants, pigments, dyes, colloidal silica, inorganic particles, inorganic oxide particles, layered inorganic compounds, leveling agents, nucleating agents, crosslinking agents, and curing agents. These additives may be used alone or in combination of two or more. It should be noted that there are no particular limitations on the proportions of the additives; they can be appropriately set according to the purpose and application.

[0140] In polyurethane dispersions and gas barrier coatings, curing agents are preferred as additives. Examples of curing agents include epoxy curing agents, melamine curing agents, carbodiimide curing agents, aziridine curing agents, oxazoline curing agents, isocyanate curing agents, and reactive curing agents. They can be used alone or in combination of two or more.

[0141] When polyurethane resin contains carboxyl groups as hydrophilic groups, epoxy curing agents, carbodiimide curing agents, and isocyanate curing agents are preferred as curing agents.

[0142] Epoxy curing agents are compounds containing epoxy groups. Known epoxy curing agents include epoxy curing agents, with epoxy-based silanes being preferred. When the polyurethane dispersion and the gas barrier coating material contain an epoxy curing agent, a polyurethane layer with excellent resistance to damp heat (retort resistance) can be obtained. In particular, the chain extender in the aforementioned polyurethane dispersion and the aforementioned gas barrier coating material contains ethylenediamine. Therefore, the epoxy curing agent can more effectively improve the resistance to damp heat (retort resistance) of the polyurethane layer.

[0143] Examples of epoxy-based silanes include, for example, silane coupling agents containing epoxy groups. More specifically, examples of epoxy-based silanes include 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropyltriethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. These can be used alone or in combination of two or more. Trialkoxysilanes are preferred as epoxy-based silanes, and 3-epoxypropoxypropyltrimethoxysilane is more preferred.

[0144] Epoxysilanes are also available as commercially available products. More specifically, examples of commercially available products include KBM-403 (epoxypropoxypropyltrimethoxysilane), KBE-403 (3-epoxypropoxypropyltriethoxysilane), KBM-402 (3-epoxypropoxypropylmethyldimethoxysilane), KBE-402 (3-epoxypropoxypropylmethyldiethoxysilane), and KBM-303 (2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane) (all manufactured by Shin-Etsu Chemical Co., Ltd.). They can be used alone or in combination of two or more.

[0145] When using an epoxy curing agent (preferably an epoxy-based silane), the amount of epoxy curing agent added can be appropriately set according to the purpose and application. For example, when the polyurethane resin contains carboxyl groups as hydrophilic groups, the amount of epoxy groups in the epoxy curing agent is, for example, 0.1 mol or more, preferably 0.3 mol or more, more preferably 0.5 mol or more, and even more preferably 0.8 mol or more, relative to 1.0 mol of carboxyl groups in the polyurethane resin. Furthermore, the amount of epoxy groups in the epoxy curing agent is, for example, 5.0 mol or less, preferably 3.0 mol or less, more preferably 2.1 mol or less, even more preferably 1.5 mol or less, and particularly preferably 1.2 mol or less, relative to 1.0 mol of carboxyl groups in the polyurethane resin.

[0146] Furthermore, relative to 100 parts by mass of the total solid components of the polyurethane dispersion and / or gas barrier coating material, the epoxy curing agent is, for example, 1.0 part by mass or more, preferably 3.0 parts by mass or more, and more preferably 5.0 parts by mass or more. Additionally, relative to 100 parts by mass of the total solid components, the epoxy curing agent is, for example, 50.0 parts by mass or less, preferably 40.0 parts by mass or less, more preferably 30.0 parts by mass or less, and even more preferably 20.0 parts by mass or less.

[0147] Carbodiimide curing agents are compounds containing carbodiimide groups (carbodiimide compounds). If polyurethane dispersions and gas barrier coating materials contain carbodiimide curing agents, polyurethane layers with excellent resistance to humid heat (pressure heat) can be obtained.

[0148] In particular, the chain extender in the aforementioned polyurethane dispersion and gas barrier coating material contains ethylenediamine. Therefore, the carbodiimide curing agent can more effectively improve the hygrothermal resistance (pressure heat resistance) of the polyurethane layer.

[0149] When using a carbodiimide curing agent (carbodiimide compound), the amount of carbodiimide curing agent added can be appropriately set according to the purpose and application. For example, when the polyurethane resin contains carboxyl groups as hydrophilic groups, the amount of carbodiimide groups in the carbodiimide curing agent is, for example, 0.05 mol or more, preferably 0.1 mol or more, more preferably 0.3 mol or more, further preferably 0.5 mol or more, more preferably 0.7 mol or more, and especially preferably 0.9 mol or more, relative to 1.0 mol of carboxyl groups in the polyurethane resin. Furthermore, the amount of carbodiimide groups in the carbodiimide curing agent is, for example, 3.0 mol or less, preferably 2.0 mol or less, more preferably 1.5 mol or less, further preferably 1.2 mol or less, and especially preferably 1.0 mol or less, relative to 1.0 mol of carboxyl groups in the polyurethane resin.

[0150] Furthermore, relative to 100 parts by mass of the total solid components of the polyurethane dispersion and / or gas barrier coating material, the carbodiimide curing agent is, for example, 1.0 part by mass or more, preferably 5.0 parts by mass or more, more preferably 9.0 parts by mass or more, even more preferably 13.0 parts by mass or more, and particularly preferably 16.0 parts by mass or more. Additionally, relative to 100 parts by mass of the total solid components, the carbodiimide curing agent is, for example, 70.0 parts by mass or less, preferably 65.0 parts by mass or less, more preferably 47.0 parts by mass or less, even more preferably 45.0 parts by mass, even more preferably 38.0 parts by mass or less, and particularly preferably 32.0 parts by mass or less.

[0151] Carbodiimide curing agents are also available in commercially available form. Commercially available carbodiimide curing agents include, for example, CARBODILITE V-02, CARBODILITE V-02-L2, CARBODILITE SV-02, CARBODILITE V-04, CARBODILITE V-10, CARBODILITE SW-12G, CARBODILITE E-02, CARBODILITE E-03A, CARBODILITE E-05 (all manufactured by Nisshinbo Chemical Inc.), Lupranate MM-103, XTB-3003 (all manufactured by BASF), Stabaxol P (manufactured by Sumitomo Bayer Urethane), PICASSIAN XL-701, XL-702, XL-721, XL-725, XL-732, XL-752, XL-755, and XL-782 (all manufactured by STAHL POLYMERS).

[0152] Known isocyanate curing agents can be cited as examples, with water-dispersible polyisocyanates being preferred. If the polyurethane dispersion and the gas barrier coating material contain an isocyanate curing agent, a polyurethane layer with excellent resistance to humid heat (pressure heat resistance) can be obtained. In particular, the chain extender in the aforementioned polyurethane dispersion and the aforementioned gas barrier coating material contains ethylenediamine. Therefore, the isocyanate curing agent can more effectively improve the humid heat resistance (pressure heat resistance) of the polyurethane layer.

[0153] Water-dispersible polyisocyanates are polyisocyanates that can be dispersed in water. Examples of water-dispersible polyisocyanates include those having an epoxy alkyl group having 2 to 3 carbon atoms as a repeating unit. They can be used alone or in combination of two or more.

[0154] Water-dispersible polyisocyanates can be obtained, for example, by dispersing polyisocyanates containing polyethylene oxide in water using known dispersants (ionic dispersants, nonionic dispersants, etc.). Water-dispersible polyisocyanates can be used alone or in combination of two or more.

[0155] When using an isocyanate curing agent, the amount of isocyanate curing agent added can be appropriately set according to the purpose and application. For example, when the polyurethane resin contains carboxyl groups as hydrophilic groups, the amount of isocyanate groups in the isocyanate curing agent is, for example, 0.1 moles or more, preferably 0.5 moles or more, more preferably 0.8 moles or more, and even more preferably 1.0 moles or more, relative to 1.0 moles of carboxyl groups in the polyurethane resin.

[0156] In addition, relative to 1.0 mole of carboxyl groups in the polyurethane resin, the isocyanate groups in the isocyanate curing agent are, for example, 5.0 moles or less, preferably 4.0 moles or less, more preferably 3.0 moles or less, even more preferably 2.1 moles or less, and especially preferably 1.8 moles or less.

[0157] Furthermore, relative to 100 parts by mass of the total solid components of the polyurethane dispersion and / or gas barrier coating material, the isocyanate curing agent is, for example, 1.0 part by mass or more, preferably 3.0 parts by mass or more, and more preferably 5.0 parts by mass or more. Additionally, relative to 100 parts by mass of the total solid components, the isocyanate curing agent is, for example, 50.0 parts by mass or less, preferably 40.0 parts by mass or less, more preferably 30.0 parts by mass or less, and even more preferably 20.0 parts by mass or less.

[0158] Isocyanate curing agents are also available in commercially available form. Commercially available isocyanate curing agents include, for example, TAKENATE WD-720, TAKENATE WD-725, TAKENATE WD-220, TAKENATE XWD-HS7, TAKENATE XWD-HS30 (all manufactured by Mitsui Chemicals), AQUANATE 100, AQUANATE 110, AQUANATE 200, AQUANATE 210 (manufactured by Nippon Polyurethane Industry Co., Ltd.), DURANATE WB40-100, DURANATE WT20-100 (manufactured by Asahikasei Chemicals Corporation), Bayhydur 3100, Bayhydur XP2487 / 1 (manufactured by Bayer MaterialScience Ltd.), Basonat HW100, and Basonat HA100 (manufactured by BASF).

[0159] From the viewpoint of improving resistance to damp heat (pressure heat), epoxy silanes, water-dispersible polyisocyanates, and carbodiimide compounds are preferably selected as curing agents. In other words, the polyurethane dispersion preferably includes at least one compound selected from the group consisting of epoxy silanes, water-dispersible polyisocyanates, and carbodiimide compounds. If the polyurethane dispersion and the gas barrier coating material contain these curing agents, a polyurethane layer with excellent resistance to damp heat (pressure heat) can be obtained.

[0160] From the viewpoint of improving resistance to damp heat (pressure heat), carbodiimide compounds are more preferably chosen as curing agents. In other words, polyurethane dispersions more preferably contain carbodiimide compounds.

[0161] There are no particular restrictions on when to add the curing agent. For example, the curing agent can be added to polyurethane dispersions and gas barrier coatings before storage.

[0162] Alternatively, a curing agent can be added, for example, to the preserved polyurethane dispersion and gas barrier coating material (i.e., the polyurethane dispersion and gas barrier coating material before use).

[0163] It should be noted that when the curing agent is added to the stored polyurethane dispersion and gas barrier coating material, the storage stability is the same as that required before the addition of the curing agent.

[0164] In other words, as long as the polyurethane dispersion has excellent storage stability before the addition of the curing agent, it is acceptable.

[0165] Alternatively, the solid component concentration of the gas barrier coating material can be adjusted by removing water from the polyurethane dispersion. Conversely, the solid component concentration can be adjusted by adding water to the polyurethane dispersion. Furthermore, the solid component concentration can also be adjusted by adding the aforementioned solvent to the polyurethane dispersion.

[0166] The solid component concentration of the gas barrier coating material is, for example, 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more. Furthermore, the solid component concentration of the polyurethane dispersion is, for example, 60% by mass or less, preferably 50% by mass or less, and more preferably 40% by mass or less.

[0167] Such a gas barrier coating material contains the aforementioned polyurethane dispersion, thus enabling the formation of a polyurethane layer with excellent gas barrier properties, heat resistance, and storage stability. Therefore, the gas barrier coating material can be appropriately used in the manufacture of laminates having a polyurethane layer as a gas barrier layer.

[0168] Figure 1 In this laminate 1, a substrate 2 and a polyurethane layer 3 disposed on the surface of the substrate 2 are included. Examples of substrate 2 include plastic, metal vapor-deposited plastic, paper, cloth, wood, metal, and ceramic. They can be used alone or in combination of two or more.

[0169] As the substrate 2, plastics, metal vapor-deposited plastics, and paper are preferred examples.

[0170] Examples of plastics include thermoplastic resins and thermosetting resins, with thermoplastic resins being preferred. Examples of thermoplastic resins include polyolefin resins, polyester resins, polyamide resins, vinyl resins, acrylic resins, polycarbonate resins, and cellulose resins. These can be used alone or in combination of two or more. Polyolefin resins, polyester resins, and polyamide resins are preferred as thermoplastic resins.

[0171] Furthermore, as the substrate 2, examples include unstretched substrates, uniaxially stretched substrates, and biaxially stretched substrates. Additionally, the substrate 2 can be a single layer or multiple layers. Furthermore, the substrate 2 can undergo surface treatment. Examples of surface treatments include corona discharge treatment and anchor coating treatment.

[0172] The shape of the substrate 2 can be, for example, film, sheet, bottle, and cup. Film is preferred.

[0173] The thickness of the substrate 2 is, for example, 3 μm or more, preferably 5 μm or more. Furthermore, the thickness of the substrate 2 is, for example, 500 μm or less, preferably 200 μm or less.

[0174] The polyurethane layer 3 comprises the polyurethane resin described above, and is preferably formed from the polyurethane resin described above. As the polyurethane layer 3, a dried product of a gas barrier coating material is preferably cited.

[0175] That is, from the viewpoint of manufacturing efficiency, the polyurethane layer 3 is preferably formed by applying a gas barrier coating material to the substrate 2 and then drying it. More specifically, in order to form the polyurethane layer 3, the aforementioned gas barrier coating material is applied to the substrate 2 and then dried. There are no particular limitations on the coating method of the gas barrier coating material. Examples of coating methods include dip coating, gravure coating, reverse coating, roller coating, bar coating, spray coating, air knife coating, and inline coating.

[0176] There are no particular limitations on the drying conditions of the barrier coating material. For example, the drying temperature is 40°C or higher, preferably 50°C or higher. Alternatively, the drying temperature is 200°C or lower, preferably 180°C or lower. The drying time is 0.1 minutes or higher, preferably 0.2 minutes or higher. Alternatively, the drying time is 10 minutes or lower, preferably 5 minutes or lower.

[0177] Thus, a polyurethane layer 3 formed of polyurethane resin is formed on the substrate 2. As a result, a laminate 1 having the substrate 2 and the polyurethane layer 3 is obtained.

[0178] In addition, polyurethane layer 3 can be cured as needed.

[0179] There are no particular restrictions on the curing conditions for the polyurethane layer 3. For example, the curing temperature is 20°C or higher, preferably 30°C or higher. The curing temperature is 100°C or lower, preferably 80°C or lower. The curing time is 1 hour or higher, preferably 10 hours or higher. The curing time is 10 days or less, preferably 7 days or less.

[0180] The lamination weight of polyurethane layer 3 is, for example, 0.1 g / m³. 2 The above is preferably 0.2 g / m 2 The above, more preferably 0.3 g / m 2 That's all. Additionally, the lamination weight of polyurethane layer 3 is, for example, 10 g / m². 2 The preferred value is 7g / m 2 The following is more preferably 5g / m 2 the following.

[0181] In addition, in laminate 1, polyurethane layer 3 can be either a cover layer or an anchor layer. When polyurethane layer 3 is a cover layer, it is the outermost layer in laminate 1.

[0182] Furthermore, if polyurethane layer 3 is an anchor coating, then polyurethane layer 3 is an intermediate layer in laminate 1. In this case, laminate 1 may further include a vapor-deposited layer (not shown) laminated on polyurethane layer 3. The vapor-deposited layer is laminated on polyurethane layer 3 by a known vapor deposition method.

[0183] Furthermore, the total thickness of the laminate 1 is, for example, 5 μm or more, preferably 10 μm or more. Additionally, the total thickness of the laminate 1 is, for example, 1 mm or less, preferably 0.5 mm or less.

[0184] Such a laminate 1 includes a polyurethane layer 3 obtained using the gas barrier coating material described above. More specifically, the polyurethane layer 3 is a dried product of the gas barrier coating material described above.

[0185] That is, in the above-described laminate 1, the polyurethane layer 3 comprises a polyurethane resin, in which the polyisocyanate component includes phenylene diisocyanate, and the chain extender comprises ethylenediamine in a specified proportion. Therefore, the above-described laminate 1 exhibits excellent gas barrier properties and heat resistance. Furthermore, if the polyurethane layer 3 includes a curing agent, the above-described laminate 1 also exhibits excellent resistance to humid heat (pressure heat resistance).

[0186] Therefore, laminate 1 exhibits excellent gas barrier properties and heat resistance. Consequently, laminate 1 can be suitable for use in various industrial sectors. It is particularly suitable for use as a packaging material.

[0187] Examples of packaging materials include food packaging films, pharmaceutical packaging films, food packaging containers, optical films, and industrial films. In particular, the laminate 1 has excellent heat resistance, and therefore can be suitable for use as a food packaging film for high-temperature sterilization and for food packaging films for heating and cooking.

[0188] Example

[0189] The present invention will now be described based on embodiments and comparative examples, but the present invention is not limited to the embodiments described below. It should be noted that unless otherwise specified, "parts" and "%" are based on mass. In addition, the specific values ​​of the proportions (including proportions), physical property values, parameters, etc. used in the following description can be replaced with the corresponding upper limit values ​​(values ​​defined in the form of "below" or "lower") or lower limit values ​​(values ​​defined in the form of "above" or "higher") of the proportions (including proportions), physical property values, parameters, etc., described in the "Specific Embodiments" above.

[0190] Synthesis example 1

[0191] Under a nitrogen atmosphere, the following raw material components are reacted at 65–70°C until the isocyanate group concentration (NCO%) is below 9.53% by mass. This yields a reaction solution containing an isocyanate-terminated prepolymer.

[0192] Raw material composition

[0193] 1,3-Phenylenediisocyanate

[0194] (TAKENATE 500, 1,3-XDI, manufactured by Mitsui Chemicals) 148.2 parts by weight of methylene bis(cyclohexyl isocyanate).

[0195] (VestanatH 12 MDI, H 12 MDI (manufactured by Evonik) 25.8 parts by weight

[0196] 29.9 parts by weight of ethylene glycol

[0197] 2.3 parts by weight of trimethylolpropane

[0198] 17.0 parts by weight of dimethylolpropionic acid

[0199] 126.9 parts by weight of methyl ethyl ketone (solvent)

[0200] Next, the reaction solution was cooled to 40°C. Then, 12.6 parts by mass of triethylamine were added to the reaction solution to neutralize the isocyanate-terminated prepolymer. Next, the reaction solution was dispersed in 1000 parts by mass of ion-exchanged water using a homogenizer. Then, an aqueous amine solution was added to the resulting dispersion to initiate a chain extension reaction, followed by aging for 1 hour. It should be noted that the aqueous amine solution was a mixture of 50 parts by mass of ion-exchanged water and 14.3 parts by mass of ethylenediamine. Then, methyl ethyl ketone and the ion-exchanged water were removed by distillation using an evaporator. The concentration of the solid component was thus adjusted to 30% by mass. This yielded a polyurethane dispersion (PUD) containing a gas-barrier polyurethane resin.

[0201] It should be noted that the molar proportion of the 3-membered or higher alcohol (trimethylolpropane) in the active hydrogen group component is calculated by known methods based on the hydroxyl equivalent (molecular weight / number of hydroxyl groups) and the amount of complexing. More specifically, the proportion of trimethylolpropane relative to the active hydrogen group component is 4.0 mol%, as shown in the following formula.

[0202] (2.3 parts by mass / 44.725) / [(29.9 parts by mass / 31.034) + (2.3 parts by mass / 44.725) + (17.0 parts by mass / 67.066)] × 100 = 4.0 mol%

[0203] Hydroxyl equivalent of ethylene glycol: 31.034

[0204] Hydroxyl equivalent of trimethylolpropane: 44.725

[0205] Hydroxyl equivalent of dimethylolpropane: 67.066

[0206] Synthesis Examples 2 to 18

[0207] Polyurethane dispersions were obtained using the same method as in Synthesis Example 1, according to the formulations recorded in Tables 1 and 2.

[0208] Examples 1-12 and Comparative Examples 1-10

[0209] Following the formulations described in Tables 3 and 4, a polyurethane dispersion, a solvent (isopropanol), and deionized water were mixed. This yielded a gas barrier coating material.

[0210] <Evaluation>

[0211] (1) Storage stability (thermal stability)

[0212] The viscosity of the polyurethane dispersions of each synthesis example at 25°C was measured under the following conditions.

[0213] Equipment: Toki Sangyo, RB-85L

[0214] Speeds: 12 rpm, 30 rpm, 60 rpm

[0215] Rotor number: No.1

[0216] Next, the polyurethane dispersion was stored at 40°C for 14 days. Then, the viscosity of the polyurethane dispersion at 25°C was measured under the above conditions. The increase in viscosity was then calculated using the following formula.

[0217] Viscosity increase rate (%) = Viscosity after storage × 100 / Viscosity before storage

[0218] (2) Coefficient of thermal expansion

[0219] The polyurethane dispersions of each synthesis example were placed in a plastic tray and dried for 1 day at 25°C and 55% relative humidity, followed by heating at 110°C for 1 hour. This yielded a polyurethane resin film (200 μm thick). The resulting film was then cut into 20 mm long and 5 mm wide pieces to obtain samples. The coefficient of thermal expansion of the samples was then determined using a thermomechanical analysis apparatus (SHIMADZU, TMA-50). It should be noted that the measurement conditions were set to a nitrogen atmosphere (gas flow rate 40 mL / min), a load of 0 g, and a heating rate of 10°C / min. The determination was performed according to JIS K7197 (1991).

[0220] Furthermore, based on Examples 1, 5-7, and Comparative Examples 2 and 4-6, the relationship between the coefficient of thermal expansion and the proportion of trimethylolpropane (TMP ratio) relative to the total amount of components containing active hydrogen groups is shown below. Figure 2 .

[0221] That is, the chain extenders in each embodiment contain ethylenediamine. Therefore, the improvement in heat resistance is particularly significant when the active hydrogen group component includes trimethylolpropane. On the other hand, the chain extenders in each comparative example do not contain ethylenediamine. Therefore, the improvement in heat resistance is small when the active hydrogen group component includes trimethylolpropane.

[0222] In addition, based on Examples 1, 8-11, Comparative Examples 2 and 7-10, the coefficient of thermal expansion and the ratio of methylene bis(cyclohexyl isocyanate) relative to the total amount of polyisocyanate components (H) were compared. 12 The relationship between the MDI ratio and the MDI proportion is shown in the figure. Figure 3 .

[0223] That is, the chain extenders in each embodiment contain ethylenediamine. Therefore, the improvement in heat resistance is particularly significant when the polyisocyanate component contains methylenebis(cyclohexyl isocyanate). On the other hand, the chain extenders in each comparative example do not contain ethylenediamine. Therefore, the improvement in heat resistance is small when the polyisocyanate component contains methylenebis(cyclohexyl isocyanate).

[0224] (3) Gas barrier properties (substrate: polyethylene terephthalate film)

[0225] As the substrate, a polyethylene terephthalate (PET) film is prepared. It should be noted that the PET film is a biaxially stretched polyester film (trade name: Toyobo PET film E5102, manufactured by Toyobo Corporation, with a thickness of 12μm).

[0226] Next, a gas barrier coating material is applied to the substrate using a bar coater. It should be noted that the coating amount is set to 1 g / m² when dry. 2 .

[0227] Next, the film coated with the gas barrier coating material was placed in a drying oven set to 110°C for 1 minute to dry it. This yielded a laminate containing a substrate and a polyurethane layer. Then, the oxygen permeability of the laminate was measured using an oxygen permeability measuring device (MOCON, OX-TRAN 2 / 20). It should be noted that the measurement conditions were set to 20°C and 70% relative humidity (70% RH). Furthermore, the measurement was performed according to JIS K7126-2 (2006). Additionally, measurements were taken for every 1 m... 2 Oxygen permeability per day and per atmosphere (cc / m³) 2 ·day·atm).

[0228] [Table 1]

[0229]

[0230] [Table 2]

[0231]

[0232] [Table 3]

[0233]

[0234] [Table 4]

[0235]

[0236] Example 13

[0237] Following the formulation described in Table 5, a polyurethane dispersion, an isocyanate curing agent (T AKENATE WD-725, manufactured by Mitsui Chemicals), a solvent (isopropanol), and deionized water were mixed. This yielded a gas barrier coating material.

[0238] (4) Gas barrier properties (substrate: polypropylene film)

[0239] As the substrate, a polypropylene film is prepared. It should be noted that the polypropylene film is an unstretched polypropylene film (TohcelloCP RXC-22 (CPP film), #60, manufactured by Mitsui Chemicals Tohcello Inc.).

[0240] Next, a gas barrier coating material is applied to the substrate using a bar coater. It should be noted that the coating amount is set to 3 g / m² when dry. 2 Next, the film coated with the gas barrier coating material was placed in a drying oven set to 80°C for 1 minute to dry it. Then, it was heated at 40°C for 2 days. This yielded a laminate containing a substrate and a polyurethane layer. The oxygen permeability was then measured in the same manner as in Example 1.

[0241] Example 14

[0242] According to the formulation described in Table 5, the polyurethane dispersion, isocyanate curing agent (T AKENATE WD-725, manufactured by Mitsui Chemicals), solvent (isopropanol), deionized water, and leveling agent (BYK-348, manufactured by BYK Corporation) were mixed. This yielded a gas barrier coating material.

[0243] (5) Gas barrier properties (substrate: polyethylene film)

[0244] A polyethylene film is prepared as the substrate. It should be noted that the polyethylene film is a low-density polyethylene film (LLDPE film, manufactured by Mitsui Chemicals Tohcello Inc., TUXHC, 60 μm thick). Next, a gas barrier coating material is applied to the substrate using a bar coater. It should be noted that the coating amount is set to 3 g / m² at the dry thickness. 2 .

[0245] Next, the film coated with the gas barrier coating material was placed in a drying oven set to 80°C for 1 minute to dry it. Then, it was heated at 40°C for 2 days. This yielded a laminate containing a substrate and a polyurethane layer. The oxygen permeability was then measured in the same manner as in Example 1.

[0246] Example 15

[0247] Following the formulation described in Table 5, a polyurethane dispersion, an isocyanate curing agent (T AKENATE WD-725, manufactured by Mitsui Chemicals), a solvent (isopropanol), and deionized water were mixed. This yielded a gas barrier coating material.

[0248] (6) Gas barrier properties (substrate: polypropylene film)

[0249] A polypropylene film is prepared as the substrate. It should be noted that the polypropylene film is an unstretched polypropylene film (Tohcello CP RXC-22 (CPP film), #60, manufactured by Mitsui Chemicals Tohcello Inc.). Next, a gas barrier coating material is applied to the substrate using a bar coater. It should be noted that the coating amount is set to 0.5 g / m² at dry thickness. 2 .

[0250] Next, the film coated with the gas barrier coating material was placed in a drying oven set to 80°C for 1 minute to dry it. Then, it was heated at 40°C for 2 days. Afterward, it was installed in a vacuum aluminum evaporation machine (Showa Vacuum, SIP600), with aluminum set as the evaporation source, and the vacuum level in the evaporation chamber was set to 2 × 10⁻⁶. -3 mbar. Then, the current value is slowly increased to dissolve the aluminum at 700mA, and the aluminum is deposited over a total evaporation time of 3 seconds. Thus, a laminate containing a substrate, a polyurethane layer, and an evaporated layer is obtained.

[0251] Then, the oxygen permeability was measured in the same manner as in Example 1.

[0252] Example 16

[0253] According to the formulation described in Table 5, the polyurethane dispersion, isocyanate curing agent (T AKENATE WD-725, manufactured by Mitsui Chemicals), solvent (isopropanol), deionized water, and leveling agent (BYK-348, manufactured by BYK Corporation) were mixed. This yielded a gas barrier coating material.

[0254] (7) Gas barrier properties (substrate: polyethylene film)

[0255] Instead of the unstretched polypropylene membrane, a low-density polyethylene membrane (LLDPE membrane, manufactured by Mitsui Chemicals Tohcello Inc., TUXHC, 60 μm thick) was used, and the procedure was otherwise the same as in Example 15 to obtain a laminate having a substrate, a polyurethane layer, and a vapor-deposited layer. Then, the oxygen permeability was measured in the same manner as in Example 1.

[0256] Example 17

[0257] Following the formulation described in Table 5, a polyurethane dispersion, an isocyanate curing agent (T AKENATE WD-725, manufactured by Mitsui Chemicals), a solvent (isopropanol), and deionized water were mixed. This yielded a gas barrier coating material.

[0258] (8) Gas barrier properties (substrate: polypropylene film)

[0259] A polypropylene film is prepared as the substrate. It should be noted that the polypropylene film is an unstretched polypropylene film (Tohcello CP RXC-22 (CPP film), #100, manufactured by Mitsui Chemicals Tohcello Inc.). Next, a gas barrier coating material is applied to the substrate using a bar coater. It should be noted that the coating amount is set to 0.5 g / m² at dry thickness. 2 .

[0260] Next, the film coated with the gas barrier coating material was placed in a drying oven set to 80°C for 1 minute to dry it. Then, it was heated at 40°C for 2 days. Next, using a batch stretching machine, after heating at a preheated temperature of 158°C for 1 minute, the film was stretched 6 times in the direction of travel.

[0261] Next, after installation in a vacuum aluminum evaporation machine (Showa Vacuum, SIP600), aluminum was set as the evaporation source, and the vacuum level in the evaporation chamber was set to 2×10⁻⁶. -3 mbar.

[0262] Then, the current value was slowly increased to dissolve the aluminum at 700 mA, and the aluminum was deposited over a total evaporation time of 3 seconds. This yielded a laminate comprising a substrate, a polyurethane layer, and the deposited layer. The oxygen permeability was then measured in the same manner as in Example 1.

[0263] Example 18

[0264] Following the formulation described in Table 5, ion-exchanged water, polyurethane dispersion, thickener (PRIMAL RM-8W, manufactured by Dow Chemical, solid content concentration 21.5%), and swelling layered inorganic compound (NTS-5, manufactured by TOPYINDUSTRIES LIMITED, solid content concentration 6%) were mixed using a mixer. This yielded a gas barrier coating material.

[0265] (9) Gas barrier properties (substrate: paper)

[0266] For coated paper (N-coat wrap L, manufactured by Nippon Paper, with a basis weight of 65 g / m²) used as a paper substrate 2The gas barrier coating material described above is applied to the coated surface of the paper substrate using a bar coater, and the coating is dried at 120°C for 90 seconds. Next, the gas barrier coating material is applied again using a bar coater, and the coating is dried at 120°C for 90 seconds. Then, it is cured at 23°C and 50% RH for 2 days. This forms a polyurethane layer on one side of the paper substrate, resulting in a laminate. It should be noted that the coating amount is set to a thickness of 6.0 g / m² at dryness. 2 Then, the oxygen permeability was measured in the same manner as in Example 1.

[0267] Example 19

[0268] Following the formulation described in Table 5, water, polyurethane dispersion, thickener (PRIM AL RM-8W, manufactured by Dow Chemical, solid content concentration 21.5%), and swelling layered inorganic compound (ME300-B4T, manufactured by Katakura & Co-op Agri Corporation, solid content concentration 8%) were mixed using a mixer. This yielded a gas barrier coating material.

[0269] (10) Gas barrier properties (substrate: paper)

[0270] For coated paper (N-coat wrap L, manufactured by Nippon Paper, with a basis weight of 65 g / m²) used as a paper substrate 2 The gas barrier coating material described above is applied to the coated surface of the paper substrate using a bar coater, and the coating is dried at 120°C for 90 seconds. Next, the gas barrier coating material is applied again using a bar coater, and the coating is dried at 120°C for 90 seconds. Then, it is cured at 23°C and 50% RH for 2 days. This forms a polyurethane layer on one side of the paper substrate, resulting in a laminate. It should be noted that the coating amount is set to a thickness of 6.0 g / m² at dryness. 2 Then, the oxygen permeability was measured in the same manner as in Example 1.

[0271] Example 20

[0272] According to the formulation described in Table 5, ion-exchanged water, polyurethane dispersion, and a swelling layered inorganic compound (NTS-5, TOPY INDUSTRIES, LIMITED, solid component concentration of 6%) were combined and mixed using a mixer. This yielded a gas barrier coating material.

[0273] (11) Gas barrier properties (substrate: paper)

[0274] For coated paper (N-coat wrap L, manufactured by Nippon Paper, with a basis weight of 65 g / m²) used as a paper substrate 2The surface to be coated was coated with OJb-51 (a water-dispersible acrylic resin dispersion, 25% solids) as the anchoring material using a bar coater, and dried at 120°C for 90 seconds. It should be noted that the coating amount of the anchoring material was set to a thickness of 2.0 g / m² at dryness. 2 .

[0275] Next, the gas barrier coating material described above was applied using a bar coater, and the coating was dried at 120°C for 90 seconds. It should be noted that the coating amount of the gas barrier coating material was set to a thickness of 2.5 g / m² upon drying. 2 Then, it was cured at 23°C and 50% RH for 2 days. This formed a polyurethane layer on one side of the paper substrate, resulting in a laminate. The oxygen permeability was then measured in the same manner as in Example 1.

[0276] Example 21

[0277] Following the formulation described in Table 5, a polyurethane dispersion, solvent (isopropanol), epoxy silane (KBM-403, manufactured by Shin-Etsu Chemical), and deionized water were mixed. This yielded a gas barrier coating material.

[0278] (12) Gas barrier properties (substrate: alumina vapor-deposited polyethylene terephthalate)

[0279] As the substrate, alumina vapor-deposited polyethylene terephthalate (Barrialox 1011HG(#12), manufactured by TORAY ADVANCED FILM CO.,LTD.) was prepared. Next, a gas barrier coating material was applied to the substrate using a bar coater. It should be noted that the coating amount was set to 0.5 g / m² at dry thickness. 2 .

[0280] Next, the film coated with the gas barrier coating material was placed in a drying oven set to 110°C for 1 minute to dry it. Then, it was heated at 50°C for 2 days. This yielded a laminate containing a substrate and a polyurethane layer. The oxygen permeability was then measured in the same manner as in Example 1.

[0281] Examples 22-32 and Comparative Examples 11-14

[0282] Following the formulations described in Tables 6 and 7, the polyurethane dispersion, solvent (isopropanol), deionized water, and curing agent are mixed. This yields a gas barrier coating material.

[0283] (13) Gas barrier properties and pressure resistance

[0284] In Examples 22-28, 31-32 and Comparative Examples 11-13, an alumina vapor-deposited polyethylene terephthalate film (alumina vapor-deposited PET, TL-PET-H, manufactured by Mitsui Chemicals Tohcello Inc.) was prepared as a substrate.

[0285] In addition, in Examples 29-30 and Comparative Example 14, an alumina-deposited biaxially stretched polypropylene film (alumina-deposited OPP) was prepared as the substrate. It should be noted that the alumina-deposited OPP was deposited on one side of the biaxially stretched polypropylene film (high heat-resistant PYLEN film, 20 μm thick, manufactured by Toyobo Co., Ltd.) using a vacuum evaporation machine (ULVAC, INC.). The deposition process involved depositing 1×10⁻⁶ OPP deposited on one side of the film. -4 Under vacuum conditions (Pa), aluminum oxide (Al2O3) is vaporized in RH mode to form a multilayer film with a metal vapor deposition layer of 10 nm thickness.

[0286] Next, a gas barrier coating material was applied to the alumina-deposited PET using a bar coater. It should be noted that the coating amount was set to 0.5 g / m² when dry. 2 Next, the film coated with the gas barrier coating material is placed in a drying oven set to 110°C for 1 minute to dry it. Then, it is heated at 50°C for 2 days. This yields a laminate containing a substrate and a polyurethane layer.

[0287] Additionally, a gas barrier coating material was applied to the alumina-deposited OPP using a bar coater. It should be noted that the coating amount was set to 0.5 g / m² when dry. 2 Next, the film coated with the gas barrier coating material is placed in a drying oven set to 80°C for 1 minute to dry it. Then, it is heated at 50°C for 2 days. This yields a laminate containing a substrate and a polyurethane layer.

[0288] The oxygen permeability of the laminate was measured using an oxygen permeability measuring device (MOCON, OX-TRAN2 / 20). It should be noted that the measurement conditions were set to 20°C and 70% relative humidity (70% RH). Furthermore, the measurement was performed according to JIS K7126-2 (2006). Additionally, measurements were taken every 1 m... 2 Oxygen permeability per day and per atmosphere (cc / m³) 2 ·day·atm).

[0289] Next, the laminate was immersed in hot water at 120°C for 30 minutes for hot water treatment. Then, the oxygen permeability of the hot water-treated laminate was measured under the above conditions. The increase rate of oxygen permeability was then calculated using the following formula. It should be noted that a higher increase rate of oxygen permeability indicates a lower evaluation of pressure heat resistance.

[0290] [(Oxygen permeability after hot water treatment - Oxygen permeability before hot water treatment) / Oxygen permeability before hot water treatment]

[0291] (14) Sealing properties and pressure resistance

[0292] Using a bar coater, a mixture of TAKELAC A-310 (manufactured by Mitsui Chemicals) and TAKENATE A-3 (manufactured by Mitsui Chemicals) used as an adhesive (TAKELAC A-310 / TAKENATE A-3 = 10 / 1 (mass ratio)) was dried to a thickness of 3.0 g / m. 2 The polyurethane layer is coated onto the laminate using a specific method and then dried using a dryer.

[0293] Next, an unstretched polypropylene film (Tohcello CP RXC-22 (CPP film), #60, manufactured by Mitsui ChemicalsTohcello Inc.) was laminated onto the adhesive-coated surface and cured at 50°C for 3 days. This yielded the laminated film.

[0294] The lamination strength of the laminate was determined by a T-peel test (15 mm width) according to JIS K 6854 (1999). Additionally, the laminate was subjected to hot water treatment by immersing it in hot water at 120°C for 30 minutes. The lamination strength of the hot water-treated laminate was then measured under the aforementioned conditions.

[0295] (15) Coefficient of thermal expansion

[0296] Each gas barrier coating material was placed in a plastic tray and dried for one day at 25°C and 55% relative humidity, followed by heating at 110°C for one hour. This yielded a polyurethane resin film (200 μm thick). The resulting film was then cut into 20 mm long and 5 mm wide pieces, thus obtaining samples. The coefficient of thermal expansion of the samples was then determined using a thermomechanical analysis apparatus (SHIMADZU, TMA-50). It should be noted that the measurement conditions were set to a nitrogen atmosphere (gas flow rate 40 mL / min), a load of 0 g, and a heating rate of 10°C / min. Furthermore, the determination was performed according to JIS K7197 (1991).

[0297] [Table 5]

[0298]

[0299] [Table 6]

[0300]

[0301] [Table 7]

[0302]

[0303] It should be noted that the following table contains details of the abbreviations.

[0304] PUD: Polyurethane Dispersion

[0305] BYK-348: Trade name BYK-348, leveling agent, manufactured by BYK Corporation.

[0306] NTS-5: Trade name NTS-5, a layered inorganic compound, manufactured by TOPY INDUSTRIES, LIMITED.

[0307] ME300-B4T: Trade name ME300-B4T, a layered inorganic compound, manufactured by Katakura & Co-op AgriCorporation.

[0308] RM-8W: Trade name PRIMAL RM-8W, thickener, manufactured by Dow Chemical.

[0309] CPP: Unstretched polypropylene film

[0310] LLDPE: Low-density polyethylene film

[0311] AlOxPET: Alumina vapor-deposited polyethylene terephthalate

[0312] Coverage: Overlay

[0313] Anchor coating: Anchor coating layer

[0314] KBM-403: Trade name KBM-403, epoxy silane, manufactured by Shin-Etsu Chemical

[0315] WD-725: Trade name TAKENATE WD-725, water-dispersible polyisocyanate, manufactured by Mitsui Chemicals.

[0316] Bayhydur 3100: Trade name Bayhydur 3100, a water-dispersible polyisocyanate, manufactured by ASF.

[0317] V-02: A carbodiimide compound, trade name CARBODILITE V-02, solid component concentration 40% by mass, manufactured by Nisshinbo Chemical Inc.

[0318] V-02-L2: A carbodiimide compound, trade name CARBODILITE V-02-L2, solid component concentration 40% by mass, manufactured by Nisshinbo Chemical Inc.

[0319] SV-02: A carbodiimide compound, trade name CARBODILITE SV-02, solid content concentration 40% by mass, manufactured by Nisshinbo Chemical Inc.

[0320] MF: Material Destruction

[0321] It should be noted that the above-described invention is provided as an illustrative embodiment of the present invention, but it is merely illustrative and not intended to be limiting. Modifications of the present invention that will be apparent to those skilled in the art are included in the appended claims.

[0322] Industrial availability

[0323] The polyurethane dispersion, gas barrier coating material, and laminate of the present invention can be suitably used in food packaging films for high-temperature sterilization and food packaging films for heating and cooking.

[0324] Explanation of reference numerals in the attached figures

[0325] 1. Layered body

[0326] 2. Substrate

[0327] 3. Polyurethane layer

Claims

1. A polyurethane dispersion, characterized in that, It is an aqueous dispersion of polyurethane resin. The polyurethane resin is a reaction product of isocyanate-terminated prepolymer and chain extender. The isocyanate-terminated prepolymer comprises a reaction product of a polyisocyanate component and a component containing active hydrogen groups. The polyisocyanate component includes phenylene diisocyanate, and the component containing active hydrogen groups includes short-chain diols with 2 to 6 carbon atoms and compounds containing hydrophilic groups. The chain extender comprises ethylenediamine. The proportion of ethylenediamine relative to the total amount of the chain extender is 25 mol% or more. The polyisocyanate component also includes methylene bis(cyclohexyl isocyanate). The content of methylene bis(cyclohexyl isocyanate) relative to the total amount of the polyisocyanate component is more than 1 mol% and less than 30 mol%. The active hydrogen group-containing component also contains alcohols with three or more nucleotides. The proportion of the tertiary or higher alcohols relative to the total amount of the active hydrogen group-containing components is 2 mol% to 15 mol%.

2. The polyurethane dispersion as described in claim 1, characterized in that, The coefficient of thermal expansion of the polyurethane resin is 2000 × 10⁻⁶. -6 K -1 the following.

3. The polyurethane dispersion of claim 1, further comprising at least one selected from the group consisting of epoxy silanes, water-dispersible polyisocyanates and carbodiimides.

4. The polyurethane dispersion as described in claim 3, wherein, The proportion of carbodiimide groups in the carbodiimide compound is more than 0.3 mol and less than 3.0 mol, relative to 1 mol of carboxyl groups in the polyurethane resin.

5. A gas barrier coating material, characterized in that, It comprises the polyurethane dispersion as described in claim 1.

6. A laminated body, characterized in that, It comprises a substrate and a polyurethane layer disposed on the surface of the substrate. The polyurethane layer is the dried product of the gas barrier coating material as described in claim 5.

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