Polyurethane dispersants, gas barrier coatings, and methods for manufacturing polyurethane dispersants.

Abstract

DEPCT68 Polyurethane dispersion consists of polyurethane resin. The polyurethane resin consists of... The product of the reaction of a prepolymer with isocyanate terminal groups with a chain extender. And / or a prepolymer end-capping compound containing isocyanate end-groups. The product of the reaction between the polyisocyanate components and other components. It contains active hydrogen groups; a component containing active hydrogen groups. It consists of polyol compounds and compounds containing active hydrogen groups. It consists of an anionic group; the anionic group is neutralized by a neutralizing agent. Neutral compounds consist of monoamine compounds containing primary or secondary amino groups;

Description

Polyurethane dispersion, gas barrier coating material, and method for producing polyurethane dispersion

[0001] The present invention relates to a polyurethane dispersion, a gas barrier coating material, and a method for producing the polyurethane dispersion.

[0002] Conventionally, it has been known to form a polyurethane layer by applying a polyurethane dispersion to the surface of a substrate and drying it. The polyurethane layer imparts various functionalities to the substrate, such as gas barrier properties and water resistance.

[0003] For example, a polyurethane dispersion obtained by the following method has been proposed: First, 1,3-xylylene diisocyanate (XDI) and 4,4'-methylenebis(cyclohexylisocyanate) (H １２ MDI) is reacted with ethylene glycol (EG), trimethylolpropane (TMP), and dimethylolpropionic acid (DMPA) to obtain an isocyanate-terminated prepolymer. Next, triethylamine (TEA) is added to the isocyanate-terminated prepolymer to neutralize the isocyanate-terminated prepolymer. Next, the isocyanate-terminated prepolymer is dispersed in water, and the isocyanate-terminated prepolymer and 2-((2-aminoethyl)amino)ethanol are subjected to a chain extension reaction in water. This results in a polyurethane dispersion containing a polyurethane resin (see, for example, Patent Document 1 (Synthesis Example 1)).

[0004] International Publication No. 2020 / 250768

[0005] On the other hand, polyurethane dispersions are required to have excellent storage stability.

[0006] The present invention relates to a polyurethane dispersion having excellent storage stability, a gas barrier coating material, and a method for producing the polyurethane dispersion.

[0007] The present invention [1] is a polyurethane dispersion containing a polyurethane resin, wherein the polyurethane resin contains a reaction product of an isocyanate-terminated prepolymer and a chain extender and / or an end-capping agent, the isocyanate-terminated prepolymer contains a reaction product of a polyisocyanate component and an active hydrogen group-containing component, the active hydrogen group-containing component contains a polyol compound and an active hydrogen group-containing compound containing an anionic group, the anionic group is neutralized with a neutralizing agent, and the neutralizing agent contains a monoamine compound having a primary amino group or a secondary amino group.

[0008] The present invention [2] includes the polyurethane dispersion according to the above [1], wherein in the monoamine compound, the total number of carbon atoms in the hydrocarbon groups bonded to the primary amino group or the secondary amino group is 2 to 6.

[0009] The present invention [3] includes the polyurethane dispersion according to the above [1] or [2], wherein the polyurethane resin has a number average molecular weight of 700 or more.

[0010] The present invention [4] includes the polyurethane dispersion according to any one of the above [1] to [3], wherein the carbonate ion concentration of the polyurethane dispersion is 700 ppm or less.

[0011] The present invention [5] includes the polyurethane dispersion according to any one of the above [1] to [4], in which the anionic group is a carboxy group.

[0012] The present invention [6] includes the polyurethane dispersion according to any one of the above [1] to [5], in which the content of the monoamine compound having a primary amino group or a secondary amino group is 25 mol % or more relative to the total moles of the neutralizing agent.

[0013] The present invention [7] comprises the polyurethane dispersion according to any one of the above [1] to [6], wherein the polyisocyanate component contains bis(isocyanatomethyl)cyclohexane and / or xylylene diisocyanate, and the polyol compound contains a short-chain diol having 2 to 6 carbon atoms.

[0014] The present invention [8] includes the polyurethane dispersion according to any one of the above [1] to [7], wherein the polyurethane resin has a urethane and urea group concentration of 33% by mass or more and 42% by mass or less.

[0015] The present invention [9] includes a gas barrier coating material containing the polyurethane dispersion described in the above [7] or [8].

[0016] The present invention

[10] is a method for producing a polyurethane dispersion containing a polyurethane resin, and includes the following steps: a prepolymer synthesis step of reacting a polyisocyanate component with a polyol compound and an active hydrogen group-containing component containing an active hydrogen group-containing compound having an anionic group to synthesize an isocyanate group-terminated prepolymer; a neutralization step of neutralizing the anionic groups with a primary neutralizer containing a monoamine compound having a tertiary amino group after the prepolymer synthesis step; a chain extension step of reacting the isocyanate group-terminated prepolymer with a chain extender after the neutralization step to obtain a polyurethane resin; and a substitution step of substituting at least a portion of the primary neutralizer with a secondary neutralizer containing a monoamine compound having a primary amino group or a secondary amino group after the chain extension step.

[0017] In the polyurethane dispersion and gas barrier coating material of the present invention, the polyurethane resin contains a reaction product of an isocyanate-terminated prepolymer with a chain extender and / or an end-capping agent. The isocyanate-terminated prepolymer contains a reaction product of a polyisocyanate component and an active hydrogen group-containing component. The active hydrogen group-containing component contains a polyol compound and an active hydrogen group-containing compound containing an anionic group. The anionic group is neutralized with a neutralizing agent. The neutralizing agent contains a monoamine compound having a primary amino group or a secondary amino group.

[0018] As a result, the polyurethane dispersion and gas barrier coating material of the present invention have excellent storage stability.

[0019] In addition, in the method for producing a polyurethane dispersion of the present invention, first, a polyisocyanate component is reacted with a polyol compound and an active hydrogen group-containing component containing an active hydrogen group-containing compound having an anionic group to synthesize an isocyanate-terminated prepolymer. Next, the anionic groups are neutralized with a primary neutralizer containing a monoamine compound having a tertiary amino group. Next, the isocyanate-terminated prepolymer is reacted with a chain extender to obtain a polyurethane resin. Thereafter, at least a portion of the primary neutralizer is replaced with a secondary neutralizer containing a monoamine compound having a primary or secondary amino group.

[0020] As a result, the method for producing a polyurethane dispersion of the present invention makes it possible to produce a polyurethane dispersion having excellent storage stability.

[0021] 1. Polyurethane Dispersion A polyurethane dispersion (PUD) contains a polyurethane resin. More specifically, a polyurethane dispersion (PUD) is an aqueous dispersion of a polyurethane resin.

[0022] (1) Polyurethane Resin The polyurethane resin contains a reaction product of an isocyanate-terminated prepolymer and a chain extender and / or an end-capping agent. Preferably, the polyurethane resin is a reaction product of an isocyanate-terminated prepolymer and a chain extender and / or an end-capping agent.

[0023] The isocyanate group-terminated prepolymer contains a reaction product of a polyisocyanate component and an active hydrogen group-containing component, and preferably consists of a reaction product of a polyisocyanate component and an active hydrogen group-containing component.

[0024] That is, the primary reaction product of the polyisocyanate component and the active hydrogen group-containing component is an isocyanate-terminated prepolymer, and the secondary reaction product of the isocyanate-terminated prepolymer and the chain extender and / or end-capping agent is a polyurethane resin.

[0025] Hereinafter, the secondary reaction product of the isocyanate-terminated prepolymer and the chain extender may be referred to as an extended polyurethane resin. Furthermore, the secondary reaction product of the isocyanate-terminated prepolymer and the end-capping agent may be referred to as a blocked polyurethane resin. Furthermore, the secondary reaction product of the isocyanate-terminated prepolymer and the chain extender and the end-capping agent may be referred to as an extended-capping hybrid polyurethane resin. Furthermore, the extended polyurethane resin, blocked polyurethane resin, and extended-capping hybrid polyurethane resin may be collectively referred to as polyurethane resins.

[0026] As described in detail below, the polyurethane resin has anionic groups. The anionic groups are neutralized with a neutralizing agent (described below). The neutralizing agent contains a monoamine compound (described below) having a primary amino group or a secondary amino group.

[0027] The stretched polyurethane resin, the sealed polyurethane resin, the stretched / sealed hybrid polyurethane resin, and the methods for producing these will be described in detail below.

[0028] (1-1) Extended Polyurethane Resin [i] Prepolymer Synthesis Step To obtain an extended polyurethane resin, first, a polyisocyanate component and an active hydrogen group-containing component are reacted to synthesize an isocyanate group-terminated prepolymer (prepolymer synthesis step).

[0029] The polyisocyanate component is not particularly limited, and examples thereof include polyisocyanates commonly used industrially. Examples of commonly used industrial polyisocyanates include linear aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates. Examples of linear aliphatic polyisocyanates include pentamethylene diisocyanate (PDI) and hexamethylene diisocyanate (HDI). Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), methylenebis(cyclohexyl isocyanate) (hydrogenated diphenylmethane diisocyanate, H １２ MDI), and bis(isocyanatomethyl)cyclohexane (hydrogenated xylylene diisocyanate, H ６ Examples of aromatic polyisocyanates include tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI). Examples of aralkyl polyisocyanates include xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI). In addition, polyisocyanates commonly used industrially may be derivatives. Examples of derivatives include polymers, isocyanurate-modified products, allophanate-modified products, polyol-modified products, biuret-modified products, urea-modified products, oxadiazinetrione-modified products, and carbodiimide-modified products. These can be used alone or in combination of two or more types.

[0030] From the viewpoint of gas barrier properties, the polyisocyanate component is preferably bis(isocyanatomethyl)cyclohexane (H ６XDI) and xylylene diisocyanate (XDI), and more preferably xylylene diisocyanate (XDI). That is, from the viewpoint of gas barrier properties, the polyisocyanate component is preferably bis(isocyanatomethyl)cyclohexane (H ６ XDI) and / or xylylene diisocyanate (XDI), and more preferably contains xylylene diisocyanate (XDI).

[0031] Examples of xylylene diisocyanate (XDI) include 1,2-xylylene diisocyanate (o-XDI), 1,3-xylylene diisocyanate (m-XDI), and 1,4-xylylene diisocyanate (p-XDI). These can be used alone or in combination of two or more. Preferred examples of xylylene diisocyanate (XDI) include 1,3-xylylene diisocyanate (m-XDI) and 1,4-xylylene diisocyanate (p-XDI), and more preferably 1,3-xylylene diisocyanate (m-XDI).

[0032] From the viewpoint of gas barrier properties, the polyisocyanate component preferably contains bis(isocyanatomethyl)cyclohexane and / or xylylene diisocyanate and other polyisocyanates. The other polyisocyanates are, for example, the above-mentioned polyisocyanates commonly used industrially, excluding bis(isocyanatomethyl)cyclohexane and xylylene diisocyanate. The other polyisocyanates can be used alone or in combination of two or more.

[0033] From the viewpoint of gas barrier properties, the other polyisocyanate is preferably an alicyclic polyisocyanate, more preferably methylenebis(cyclohexylisocyanate)(H １２That is, from the viewpoint of gas barrier properties, the polyisocyanate component preferably contains bis(isocyanatomethyl)cyclohexane and / or xylylene diisocyanate and an alicyclic polyisocyanate, and more preferably contains bis(isocyanatomethyl)cyclohexane and / or xylylene diisocyanate and methylenebis(cyclohexyl isocyanate).

[0034] When bis(isocyanatomethyl)cyclohexane and / or xylylene diisocyanate are used in combination with other polyisocyanates (preferably methylenebis(cyclohexylisocyanate)), the content ratios thereof are appropriately set depending on the purpose and application.

[0035] For example, from the viewpoint of gas barrier properties, the content of bis(isocyanatomethyl)cyclohexane and / or xylylene diisocyanate is, for example, 50% by mass or more, preferably 60% by mass or more, and more preferably 80% by mass or more, relative to the total amount of polyisocyanate components, and the content of bis(isocyanatomethyl)cyclohexane and / or xylylene diisocyanate is, for example, 100% by mass or less, preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to the total amount of polyisocyanate components.

[0036] From the viewpoint of gas barrier properties, the content of the other polyisocyanate (preferably methylenebis(cyclohexylisocyanate)) relative to the total amount of polyisocyanate components is, for example, 0% by mass or more, preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. The content of the other polyisocyanate (preferably methylenebis(cyclohexylisocyanate)) relative to the total amount of polyisocyanate components is, for example, 50% by mass or less, preferably 40% by mass or less, and more preferably 20% by mass or less.

[0037] The active hydrogen group-containing component is an organic compound containing an active hydrogen group. Examples of the active hydrogen group include a hydroxyl group and an amino group, and preferably a hydroxyl group. The active hydrogen group-containing component contains a polyol compound and an active hydrogen group-containing compound containing an anionic group.

[0038] The polyol compound is a compound containing two or more hydroxyl groups in the molecule. The polyol compound is a compound excluding the active hydrogen group-containing compound containing an anionic group and the active hydrogen group-containing compound containing a nonionic group, which will be described later. Examples of the polyol compound include low molecular weight polyols and high molecular weight polyols.

[0039] A low-molecular-weight polyol is an organic compound having two or more hydroxyl groups in the molecule and having a relatively low molecular weight. A relatively low molecular weight refers to a molecular weight of 50 or more and 650 or less. When the low-molecular-weight polyol has a molecular weight distribution, the molecular weight refers to the number average molecular weight in terms of polystyrene measured by GPC. Examples of low-molecular-weight polyols include short-chain diols having 2 to 6 carbon atoms, diols having 7 or more carbon atoms, and trivalent or higher low-molecular-weight polyols.

[0040] A short-chain diol having 2 to 6 carbon atoms is an organic compound having 2 to 6 carbon atoms and two hydroxyl groups per molecule. Examples of short-chain diols include alkanediols having 2 to 6 carbon atoms, etherdiols having 2 to 6 carbon atoms, and alkenediols having 2 to 6 carbon atoms. Examples of alkanediols having 2 to 6 carbon atoms include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,3-cyclohexanediol, and 1,4-cyclohexanediol. Examples of etherdiols having 2 to 6 carbon atoms include diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of alkene diols having 2 to 6 carbon atoms include 1,4-dihydroxy-2-butene. These can be used alone or in combination of two or more. From the viewpoint of gas barrier properties, preferred are alkane diols having 2 to 6 carbon atoms, and more preferred is ethylene glycol.

[0041] The content of the short-chain diol having 2 to 6 carbon atoms is, for example, 10 parts by mass or more, preferably 30 parts by mass or more, and more preferably 50 parts by mass or more, per 100 parts by mass of the total amount of the active hydrogen group-containing components. The content of the short-chain diol having 2 to 6 carbon atoms is, for example, 90 parts by mass or less, preferably 80 parts by mass or less, and more preferably 70 parts by mass or less, per 100 parts by mass of the total amount of the active hydrogen group-containing components.

[0042] The diol having 7 or more carbon atoms is an organic compound having 7 or more carbon atoms and having two hydroxyl groups per molecule. Examples of diols having 7 or more carbon atoms include alkanediols having 7 to 20 carbon atoms, 2,6-dimethyl-1-octene-3,8-diol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and bisphenol A. Further examples of diols having 7 or more carbon atoms include polyoxyethylene glycol and polyoxypropylene glycol having a relatively low molecular weight (molecular weight of 650 or less). These can be used alone or in combination of two or more types.

[0043] The content of the diol having 7 or more carbon atoms is, for example, 0 parts by mass or more relative to 100 parts by mass of the total amount of the active hydrogen group-containing component. The content of the diol having 7 or more carbon atoms is, for example, 70 parts by mass or less, preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 10 parts by mass or less relative to 100 parts by mass of the total amount of the active hydrogen group-containing component.

[0044] Examples of trihydric or higher low molecular weight polyols include trihydric alcohols, tetrahydric alcohols, pentahydric alcohols, hexahydric alcohols, heptahydric alcohols, and octahydric alcohols. Trihydric or higher low molecular weight polyols are preferably trihydric alcohols and tetrahydric alcohols. Examples of trihydric alcohols include glycerin, 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 diglycerin. These can be used alone or in combination of two or more. Examples of trihydric or higher low molecular weight polyols are preferably trihydric alcohols, more preferably trimethylolpropane.

[0045] The content of the trivalent or higher low-molecular-weight polyol is, for example, 0 part by mass or more, preferably 1 part by mass or more, more preferably 2 parts by mass or more, relative to 100 parts by mass of the total amount of the active hydrogen group-containing components. The content of the trivalent or higher low-molecular-weight polyol is, for example, 20 parts by mass or less, preferably 10 parts by mass or less, more preferably 8 parts by mass or less, relative to 100 parts by mass of the total amount of the active hydrogen group-containing components.

[0046] The high molecular weight polyol has two or more hydroxyl groups in the molecule and is a relatively high molecular weight organic compound (polymer). The number average molecular weight of the high molecular weight polyol is, for example, more than 650 and, for example, 20,000 or less. The number average molecular weight indicates the number average molecular weight in terms of polystyrene measured by GPC. Examples of high molecular weight polyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These may be used alone or in combination of two or more. From the viewpoint of gas barrier properties, the active hydrogen group-containing component preferably does not contain a high molecular weight polyol.

[0047] From the viewpoint of gas barrier properties, the polyol compound is preferably a low-molecular-weight polyol, more preferably a short-chain diol having 2 to 6 carbon atoms. That is, from the viewpoint of gas barrier properties, the polyol compound preferably contains a low-molecular-weight polyol, more preferably a short-chain diol having 2 to 6 carbon atoms. From the viewpoint of gas barrier properties, the polyol compound further preferably contains a short-chain diol having 2 to 6 carbon atoms and a low-molecular-weight polyol having a valence of 3 or more, and even more preferably contains a short-chain diol having 2 to 6 carbon atoms and a trihydric alcohol. From the viewpoint of gas barrier properties, the polyol compound further preferably does not contain a high-molecular-weight polyol (a high-molecular-weight polyol having a number average molecular weight exceeding 650), and is composed of a low-molecular-weight polyol, particularly preferably a short-chain diol having 2 to 6 carbon atoms and a trihydric alcohol.

[0048] When the polyol compound contains a short-chain diol having 2 to 6 carbon atoms and a low-molecular-weight polyol having a trihydric or higher hydric group, the content ratio thereof is appropriately set depending on the purpose and application. For example, the content ratio of the short-chain diol having 2 to 6 carbon atoms is, for example, 80 parts by mass or more, preferably 85 parts by mass or more, and more preferably 90 parts by mass or more, relative to 100 parts by mass of the total amount of the short-chain diol having 2 to 6 carbon atoms and the low-molecular-weight polyol having a trihydric or higher hydric group. Furthermore, the content ratio of the short-chain diol having 2 to 6 carbon atoms is, for example, 98 parts by mass or less, preferably 95 parts by mass or less, relative to 100 parts by mass of the total amount of the short-chain diol having 2 to 6 carbon atoms and the low-molecular-weight polyol having a trihydric or higher hydric group. Furthermore, the content ratio of the low-molecular-weight polyol having a trihydric or higher hydric group is, for example, 2 parts by mass or more, preferably 5 parts by mass or more, relative to 100 parts by mass of the short-chain diol having 2 to 6 carbon atoms and the low-molecular-weight polyol having a trihydric or higher hydric group. Furthermore, the content of the trivalent or higher low-molecular-weight polyol relative to 100 parts by mass of the total amount of the short-chain diol having 2 to 6 carbon atoms and the trivalent or higher low-molecular-weight polyol is, for example, 20 parts by mass or less, preferably 15 parts by mass or less, and more preferably 10 parts by mass or less.

[0049] The active hydrogen group-containing compound containing an anionic group is an organic compound that has both an anionic group and an active hydrogen group in one molecule.The anionic group can be, for example, a carboxy group (carboxylic acid group) or a sulfo group (sulfonic acid group), and from the viewpoint of water dispersibility, the carboxy group is preferred.The active hydrogen group can be, for example, a hydroxyl group or an amino group, and the hydroxyl group is preferred.

[0050] As the active hydrogen group-containing compound containing an anionic group, preferably, an organic compound having one carboxy group and two or more hydroxyl groups in one molecule is used, and more preferably, an organic compound having one carboxy group and two hydroxyl groups in one molecule is used. Examples of organic compounds having one carboxy group and two hydroxyl groups in one molecule include carboxy group-containing diols. Examples of carboxy group-containing diols include dihydroxyalkanoic acids. Examples of dihydroxyalkanoic acids include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid (also known as dimethylolpropionic acid), 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid. These can be used alone or in combination of two or more. From the viewpoint of water dispersibility, 2,2-dimethylolpropionic acid is preferred.

[0051] The content of the active hydrogen group-containing compound containing an anionic group is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, per 100 parts by mass of the total amount of the active hydrogen group-containing components, and the content of the active hydrogen group-containing compound containing an anionic group is, for example, 50 parts by mass or less, preferably 40 parts by mass or less, per 100 parts by mass of the total amount of the active hydrogen group-containing components.

[0052] The active hydrogen group-containing component may, if necessary, further contain an active hydrogen group-containing compound containing a nonionic group in addition to the polyol compound and the active hydrogen group-containing compound containing an anionic group.

[0053] The nonionic group is a polyoxyethylene group capped at one end, more specifically, a polyoxyethylene group capped at one end with an alkoxy group. That is, the nonionic group is defined as a polyoxyethylene group capped at one end with an alkoxy group (e.g., an alkoxy group having 1 to 4 carbon atoms). A polyoxyethylene group that is not capped at one end and has hydroxyl groups at both ends (i.e., polyoxyethylene glycol) is the above-mentioned polyol compound and is not included in the active hydrogen group-containing compound that contains a nonionic group.

[0054] More specifically, examples of the active hydrogen group-containing compound containing a nonionic group include one-end-capped (one-end alkoxy-capped) polyoxyethylene glycol and nonionic side chain-containing polyol, preferably nonionic side chain-containing polyol. Examples of the nonionic side chain-containing polyol include nonionic side chain-containing diol. Examples of the nonionic side chain-containing diol include one-end alkoxy-capped polyoxyethylene side chain-containing polyol. These active hydrogen group-containing compounds containing a nonionic group are prepared by known methods. The active hydrogen group-containing compounds containing a nonionic group can be used alone or in combination of two or more types. The content ratio of the active hydrogen group-containing compound containing a nonionic group is appropriately set depending on the purpose and application.

[0055] The active hydrogen group-containing component preferably comprises the above polyol compound and the above active hydrogen group-containing compound containing an anionic group. More specifically, the active hydrogen group-containing component preferably comprises a short-chain diol having 2 to 6 carbon atoms and an active hydrogen group-containing compound containing an anionic group, or a short-chain diol having 2 to 6 carbon atoms, an active hydrogen group-containing compound containing an anionic group, and a trivalent or higher low-molecular-weight polyol. The active hydrogen group-containing component more preferably comprises a short-chain diol having 2 to 6 carbon atoms, an active hydrogen group-containing compound containing an anionic group, and a trivalent or higher low-molecular-weight polyol.

[0056] The method for synthesizing the isocyanate-terminated prepolymer is not particularly limited. For example, the above-mentioned components are mixed in a predetermined equivalent ratio and reacted.

[0057] More specifically, the equivalent ratio of isocyanate groups in the polyisocyanate component to the active hydrogen groups (hydroxyl groups and amino groups) in the active hydrogen group-containing component (isocyanate groups / active hydrogen groups) is, for example, more than 1, and preferably 1.1 or more. Also, the equivalent ratio of isocyanate groups in the polyisocyanate component to the active hydrogen groups (hydroxyl groups and amino groups) in the active hydrogen group-containing component (isocyanate groups / active hydrogen groups) is, for example, 20 or less, and preferably 10 or less.

[0058] Known polymerization methods are used to synthesize isocyanate-terminated prepolymers. Examples of polymerization methods include bulk polymerization and solution polymerization. From the perspective of adjusting reactivity, solution polymerization is preferably used as the polymerization method. In bulk polymerization, for example, the above components are blended and reacted under a nitrogen atmosphere. The reaction temperature is, for example, 75 to 85°C. The reaction time is, for example, 1 to 20 hours. In solution polymerization, for example, the above components are blended and reacted in an organic solvent under a nitrogen atmosphere. The reaction temperature is, for example, 20 to 80°C. The reaction time is, for example, 1 to 20 hours. Examples of organic solvents include solvents inactive to isocyanate groups. Examples of organic solvents include acetone, methyl ethyl ketone, ethyl acetate, tetrahydrofuran, and acetonitrile. These can be used alone or in combination. Furthermore, in the above polymerization, a catalyst can be added as needed. Examples of catalysts include amine-based catalysts and organometallic catalysts. These can be used alone or in combination. The amount of catalyst added is appropriately determined depending on the purpose and application.

[0059] In the synthesis of the isocyanate-terminated prepolymer, the polymerization is continued until the isocyanate group concentration of the reaction product liquid reaches the isocyanate group concentration of the isocyanate-terminated prepolymer described below. Thereafter, if necessary, unreacted polyisocyanate components are removed from the reaction product liquid by a known removal method. Examples of the removal method include distillation and extraction. This results in the isocyanate-terminated prepolymer.

[0060] The isocyanate group concentration of the isocyanate group-terminated prepolymer is, for example, 4% by mass or more, preferably 5% by mass or more, more preferably 6% by mass or more, and 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.

[0061] The isocyanate group-terminated prepolymer has an average number of isocyanate groups of, for example, 1.5 or more, preferably 1.9 or more, or more preferably 2.0 or more, and for example, 3.0 or less, or preferably 2.5 or less.

[0062] [ii] Neutralization Step: The isocyanate-terminated prepolymer has an anionic group derived from an active hydrogen compound containing an anionic group. Therefore, in this method, after the prepolymer synthesis step, the anionic group of the isocyanate-terminated prepolymer is neutralized with a neutralizing agent (neutralization step).

[0063] Hereinafter, the neutralizing agent used in the neutralization step may be referred to as a primary neutralizing agent. Also, the neutralizing agent used in the substitution step described below may be referred to as a secondary neutralizing agent. The primary neutralizing agent and the secondary neutralizing agent may be collectively referred to as neutralizing agents.

[0064] The primary neutralizing agent contains a monoamine compound having a tertiary amino group, and preferably consists of a monoamine compound having a tertiary amino group. Hereinafter, the monoamine compound having a tertiary amino group will be referred to as a tertiary monoamine.

[0065] Examples of tertiary monoamines include trialkylamines and alkanolamines. Examples of trialkylamines include trialkylamines having 1 to 4 carbon atoms. Examples of trialkylamines having 1 to 4 carbon atoms include trimethylamine (TMA) and triethylamine (TEA). Examples of alkanolamines include dimethylethanolamine, methyldiethanolamine, triethanolamine, and triisopropanolamine. These can be used alone or in combination of two or more.

[0066] From the viewpoint of storage stability, the tertiary monoamine is preferably a trialkylamine, more preferably a trialkylamine having 1 to 4 carbon atoms, even more preferably trimethylamine (TMA) or triethylamine (TEA), and particularly preferably triethylamine (TEA).

[0067] The primary neutralizer can be used as a primary neutralizer solution. The primary neutralizer solution is prepared, for example, by dissolving the primary neutralizer in the organic solvent. The solids concentration of the primary neutralizer solution is appropriately set depending on the purpose and application.

[0068] The amount of the primary neutralizing agent (tertiary monoamine) added is, for example, 0.4 equivalents or more, preferably 0.6 equivalents or more, relative to 1 equivalent of the anionic group, and is, for example, 1.2 equivalents or less, preferably 1.0 equivalents or less, relative to 1 equivalent of the anionic group.

[0069] The addition of a primary neutralizing agent (tertiary monoamine) neutralizes the anionic groups of the isocyanate-terminated prepolymer, thereby forming a salt of the anionic groups (tertiary amine salt).

[0070] [iii] Chain Extension Step Next, in this method, after the neutralization step, the isocyanate-terminated prepolymer (primary reaction product) is reacted with a chain extender to obtain an extended polyurethane resin (secondary reaction product). For example, the isocyanate-terminated prepolymer and the chain extender are subjected to a chain extension reaction in water to obtain an extended polyurethane resin (chain extension step).

[0071] The chain extender is an organic compound that causes a chain extension reaction of the isocyanate-terminated prepolymer. The chain extender is, for example, an organic compound having two or more active hydrogen groups (hydroxyl groups and / or amino groups) in the molecule, and is preferably an organic compound having two or more amino groups in the molecule, or an organic compound having one or more hydroxyl groups and one or more amino groups in the molecule.

[0072] Examples of chain extenders include polyamines and amino alcohols. Examples of polyamines include aromatic polyamines, araliphatic polyamines, alicyclic polyamines, aliphatic polyamines, and polyoxyethylene group-containing polyamines. Examples of aromatic polyamines include 4,4'-diphenylmethanediamine and tolylenediamine. Examples of araliphatic polyamines include 1,3-xylylenediamine and 1,4-xylylenediamine. Examples of alicyclic polyamines include 3-aminomethyl-3,5,5-trimethylcyclohexylamine (also known as isophoronediamine), 4,4'-dicyclohexylmethanediamine, 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, 1,4-cyclohexanediamine, 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. Examples of aliphatic polyamines include ethylenediamine, propylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexamethylenediamine, hydrazine, hydrazine hydrate, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1,2-diaminoethane, 1,2-diaminopropane, and 1,3-diaminopentane. Examples of polyoxyethylene group-containing polyamines include polyoxyalkylene ether diamines. Examples of polyoxyalkylene ether diamines include polyoxyethylene ether diamines. Examples of amino alcohols include 2-(2-aminoethylamino)ethanol and 2-(2-aminoethylamino)-1-methylpropanol.

[0073] Furthermore, examples of chain extenders include amino group-containing alkoxysilyl compounds. Examples of amino group-containing alkoxysilyl compounds include alkoxysilyl compounds having a primary amino group. Examples of alkoxysilyl compounds having a primary amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane. Furthermore, examples of amino group-containing alkoxysilyl compounds include alkoxysilyl compounds having a primary amino group and a secondary amino group. Examples of alkoxysilyl compounds having a primary amino group and a secondary amino group include N-β(aminoethyl)γ-aminopropyltrimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane), N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, and N-β(aminoethyl)γ-aminopropylmethyldiethoxysilane.

[0074] The chain extender can be used alone or in combination of two or more kinds. Preferred examples of the chain extender include aliphatic polyamines and amino alcohols, and more preferred examples include ethylenediamine and 2-(2-aminoethylamino)ethanol.

[0075] The chain extender can be used as a chain extender solution. The chain extender solution is prepared, for example, by dissolving the chain extender in water. The solids concentration of the chain extender solution is appropriately set depending on the purpose and application.

[0076] The method for reacting the isocyanate-terminated prepolymer with the chain extender in water is not particularly limited. For example, first, the isocyanate-terminated prepolymer is dispersed in water. Next, the chain extender is added to the water in which the isocyanate-terminated prepolymer is dispersed, and the isocyanate-terminated prepolymer is chain-extended in water. The method for dispersing the isocyanate-terminated prepolymer in water is not particularly limited. For example, the isocyanate-terminated prepolymer is added to water while stirring. In this case, the amount of water is 100 to 1,000 parts by mass per 100 parts by mass of the isocyanate-terminated prepolymer. Then, the chain extender is added dropwise to the water in which the isocyanate-terminated prepolymer is dispersed while stirring. In this case, the equivalent ratio of the active hydrogen groups of the chain extender to the isocyanate groups of the isocyanate-terminated prepolymer (active hydrogen groups / isocyanate groups) is, for example, 0.8 to 1.2. The chain extension reaction is completed, for example, at room temperature. The time required for the reaction to be completed is, for example, 0.1 to 10 hours. In this method, the organic solvent and / or water can be removed after the reaction is completed in order to adjust the solid content concentration. In this method, water can be added after the reaction is completed in order to adjust the solid content concentration.

[0077] The chain extension reaction produces an aqueous dispersion of an extended polyurethane resin (hereinafter referred to as a primary polyurethane dispersion or primary PUD). The primary polyurethane dispersion (primary PUD) contains an extended polyurethane resin whose anionic groups have been neutralized with the primary neutralizer described above but not with the secondary neutralizer described below.

[0078] [iv] Substitution Step Next, in this method, after the chain extension step, at least a portion of the primary neutralizing agent is substituted with a secondary neutralizing agent (substitution step).

[0079] The secondary neutralizing agent contains a monoamine compound having a primary or secondary amino group, and preferably consists of a monoamine compound having a primary or secondary amino group. Hereinafter, the monoamine compound having a primary or secondary amino group will be referred to as a primary or secondary monoamine.

[0080] Examples of primary and secondary monoamines include primary monoamines and secondary monoamines. Examples of primary monoamines include aliphatic primary monoamines, alicyclic primary monoamines, aromatic primary monoamines, araliphatic primary monoamines, and primary monoaminosilanes. Examples of aliphatic primary monoamines include methylamine, 1-ethylamine, 1-propylamine, isopropylamine, 1-butylamine, isobutylamine, s-butylamine, t-butylamine, hexylamine, and octylamine. Examples of alicyclic primary monoamines include cyclohexylamine. Examples of aromatic primary monoamines include aniline (phenylamine). Examples of araliphatic primary monoamines include benzylamine. Examples of primary monoaminosilanes include 3-aminopropyltriethoxysilane. Examples of secondary monoamines include aliphatic secondary monoamines. Examples of aliphatic secondary monoamines include dialkylamines. Examples of dialkylamines include dimethylamine, diethylamine, methylethylamine, dipropylamine, diisopropylamine, dibutylamine, and diisobutylamine. These can be used alone or in combination of two or more. As the primary and secondary monoamines, primary monoamines are preferred.

[0081] From the viewpoint of storage stability, the primary and secondary monoamines are preferably monoamine compounds in which the total number of carbon atoms in the hydrocarbon groups bonded to the primary amino group or the secondary amino group is 2 to 6. More specific examples of such monoamine compounds include primary monoamines having 2 to 6 carbon atoms and secondary amine compounds having 2 to 6 carbon atoms. Examples of primary monoamines having 2 to 6 carbon atoms include 1-ethylamine (2 carbon atoms), 1-propylamine (3 carbon atoms), isopropylamine (3 carbon atoms), 1-butylamine (4 carbon atoms), isobutylamine (4 carbon atoms), s-butylamine (4 carbon atoms), t-butylamine (4 carbon atoms), 1-hexylamine (6 carbon atoms), cyclohexylamine (6 carbon atoms), aniline (6 carbon atoms), and 3-aminopropyltriethoxysilane (3 carbon atoms). Examples of secondary amine compounds having 2 to 6 carbon atoms include dimethylamine (having 2 carbon atoms), diethylamine (having 4 carbon atoms), methylethylamine (having 3 carbon atoms), and dipropylamine (having 6 carbon atoms).

[0082] From the viewpoint of storage stability, the primary and secondary monoamines are more preferably monoamine compounds in which the total number of carbon atoms in the hydrocarbon groups bonded to the primary amino group or secondary amino group is 2 to 4. Specific examples of such monoamine compounds include primary monoamines having 2 to 4 carbon atoms and secondary amine compounds having 2 to 4 carbon atoms. Examples of primary monoamines having 2 to 4 carbon atoms include 1-ethylamine (2 carbon atoms), 1-propylamine (3 carbon atoms), isopropylamine (3 carbon atoms), 1-butylamine (4 carbon atoms), isobutylamine (4 carbon atoms), s-butylamine (4 carbon atoms), t-butylamine (4 carbon atoms), and 3-aminopropyltriethoxysilane (3 carbon atoms). Examples of secondary amine compounds having 2 to 4 carbon atoms include dimethylamine (2 carbon atoms), diethylamine (4 carbon atoms), and methylethylamine (3 carbon atoms).

[0083] From the viewpoint of storage stability, more preferred primary and secondary monoamines include 1-propylamine (having 3 carbon atoms) and 1-butylamine (having 4 carbon atoms), and particularly preferred is 1-propylamine (having 3 carbon atoms).

[0084] The secondary neutralizer can be used as a secondary neutralizer solution. The secondary neutralizer solution is prepared, for example, by dissolving the secondary neutralizer in the organic solvent. The solids concentration of the secondary neutralizer solution is appropriately set depending on the purpose and application.

[0085] The primary neutralizer can be replaced with the secondary neutralizer, for example, by adding the secondary neutralizer to the primary polyurethane dispersion (primary PUD) and maintaining the mixture at a predetermined temperature for a predetermined time.

[0086] From the viewpoint of storage stability, for example, the amount of secondary neutralizer (primary or secondary monoamine) added relative to 1 mole of primary neutralizer (tertiary monoamine) is, for example, 0.5 moles or more, preferably 0.7 moles or more, more preferably 0.9 moles or more. Also, the amount of secondary neutralizer (primary or secondary monoamine) added relative to 1 mole of primary neutralizer (tertiary monoamine) is, for example, 3.0 moles or less, preferably 2.0 moles or less, more preferably 1.2 moles or less.

[0087] The holding environment is atmospheric air. The holding temperature is, for example, 5°C or higher, preferably 40°C or higher. The holding temperature is, for example, 80°C or lower, preferably 60°C or lower. The holding time is, for example, 20 minutes or longer, preferably 30 minutes or longer. The holding time is, for example, 24 hours or shorter, preferably 12 hours or shorter.

[0088] As a result, at least a portion of the primary neutralizing agent (tertiary monoamine) is replaced with the secondary neutralizing agent (primary or secondary monoamine).

[0089] The number of times of adding and maintaining (replacing) the secondary neutralizing agent is not particularly limited and may be one or more times. From the viewpoint of production efficiency, the number of times of adding and maintaining (replacing) the secondary neutralizing agent is preferably one.

[0090] In this method, the organic solvent and / or water can be removed after the substitution to adjust the solids concentration, and water can be added after the substitution to adjust the solids concentration.

[0091] This process produces an aqueous dispersion of an extended polyurethane resin (hereinafter referred to as a secondary polyurethane dispersion or secondary PUD). The secondary polyurethane dispersion (secondary PUD) contains an extended polyurethane resin whose anionic groups have been neutralized with the primary or secondary monoamine (secondary neutralizer).

[0092] (1-2) Capped Polyurethane Resin [i] Prepolymer Synthesis Step To obtain a capped polyurethane resin, first, a polyisocyanate component and an active hydrogen group-containing component are reacted to synthesize an isocyanate group-terminated prepolymer (prepolymer synthesis step).

[0093] Examples of the polyisocyanate component include the polyisocyanate component described above as a raw material for the extended polyurethane resin. Examples of the active hydrogen group-containing component include the active hydrogen group-containing component described above as a raw material for the extended polyurethane resin.

[0094] In the prepolymer synthesis step in the production of the encapsulated polyurethane resin, for example, a polyisocyanate component and an active hydrogen group-containing component are reacted in the same manner as in the prepolymer synthesis step in the production of the extended polyurethane resin, thereby obtaining an isocyanate-terminated prepolymer.

[0095] [ii] Neutralization Step: The isocyanate-terminated prepolymer has an anionic group derived from an active hydrogen compound containing an anionic group. Therefore, in this method, after the prepolymer synthesis step, the anionic group of the isocyanate-terminated prepolymer is neutralized with a neutralizing agent (neutralization step).

[0096] In the neutralization step in the production of the encapsulated polyurethane resin, for example, the anionic groups of the isocyanate-terminated prepolymer are neutralized with a primary neutralizer in the same manner as in the neutralization step in the production of the extended polyurethane resin, thereby forming a salt of the anionic group (a tertiary amine salt).

[0097] [iii] Capping / Substitution Step: After the neutralization step, the method then reacts the isocyanate-terminated prepolymer (primary reaction product) with a terminal-capping agent to obtain a blocked polyurethane resin (secondary reaction product). For example, the blocked polyurethane resin is obtained by subjecting the isocyanate-terminated prepolymer and the terminal-capping agent to a terminal-capping reaction in water. Furthermore, in this step, at least a portion of the primary neutralizing agent is replaced with the terminal-capping agent (capping / substitution step).

[0098] The end-capping agent is an organic compound that blocks the isocyanate groups at the molecular ends of the isocyanate-terminated prepolymer. The end-capping agent is, for example, an organic compound having one active hydrogen group (hydroxyl group and / or amino group) in the molecule, and preferably an organic compound having one or more amino groups in the molecule.

[0099] Examples of the terminal blocking agent include monoamines. Examples of the monoamine include the above-mentioned primary and secondary monoamines. The terminal blocking agent is preferably composed of the above-mentioned primary and secondary monoamines.

[0100] From the viewpoint of storage stability, the primary or secondary monoamine is preferably a primary monoamine. From the viewpoint of storage stability, the primary or secondary monoamine is preferably a monoamine compound in which the total number of carbon atoms in the hydrocarbon groups bonded to the primary amino group or secondary amino group is 2 to 6, and more preferably a monoamine compound in which the total number of carbon atoms in the hydrocarbon groups bonded to the primary amino group or secondary amino group is 2 to 4.

[0101] From the viewpoint of storage stability, more preferred primary and secondary monoamines include 1-propylamine (having 3 carbon atoms) and 1-butylamine (having 4 carbon atoms), and particularly preferred is 1-propylamine (having 3 carbon atoms).

[0102] The terminal blocking agent can be used as a terminal blocking agent solution. The terminal blocking agent solution is prepared, for example, by dissolving the terminal blocking agent in the organic solvent. The solids concentration of the terminal blocking agent solution is appropriately set depending on the purpose and application.

[0103] A method for capping the isocyanate groups at the molecular ends of the isocyanate-terminated prepolymer with an end-capping agent and substituting the primary neutralizer with the end-capping agent involves, for example, adding the end-capping agent to the isocyanate-terminated prepolymer and maintaining the mixture at a predetermined temperature for a predetermined time.

[0104] From the viewpoint of storage stability, for example, the equivalent ratio of the active hydrogen groups of the end-capping agent to the isocyanate groups of the isocyanate group-terminated prepolymer (active hydrogen groups / isocyanate groups) is, for example, 1.01 or more and 5.0 or less.

[0105] The holding environment is atmospheric air. The holding temperature is, for example, 5°C or higher, preferably 40°C or higher. The holding temperature is, for example, 80°C or lower, preferably 60°C or lower. The holding time is, for example, 20 minutes or longer, preferably 30 minutes or longer. The holding time is, for example, 24 hours or shorter, preferably 12 hours or shorter.

[0106] As a result, the isocyanate groups at the molecular ends of the isocyanate-terminated prepolymer are capped with the end-capping agent (primary or secondary monoamine), and at least a portion of the primary neutralizer (tertiary monoamine) is substituted with the end-capping agent (primary or secondary monoamine), thereby producing a capped polyurethane resin.

[0107] The number of times the terminal blocking agent is added and maintained (replaced) is not particularly limited and may be one or more times. From the viewpoint of production efficiency, the number of times the terminal blocking agent is added and maintained (replaced) is preferably one.

[0108] In this method, the organic solvent and / or water can be removed after the substitution to adjust the solids concentration, and water can be added after the substitution to adjust the solids concentration.

[0109] In this manner, an aqueous dispersion of the encapsulated polyurethane resin (polyurethane dispersion, PUD) is obtained.

[0110] (1-3) Stretched / Camped Hybrid Polyurethane Resin In the above explanation, in the production of the polyurethane resin, an isocyanate-terminated prepolymer is neutralized with a primary neutralizer, and then the isocyanate groups at the molecular terminals are reacted with a chain extender, and the primary neutralizer is replaced with a secondary neutralizer; alternatively, an isocyanate-terminated prepolymer is neutralized with a primary neutralizer, and then the isocyanate groups at the molecular terminals are capped with a terminal-capping agent, and the primary neutralizer is replaced with the terminal-capping agent.

[0111] On the other hand, in the production of polyurethane resins, for example, an isocyanate-terminated prepolymer can be neutralized with a primary neutralizer, then some of the isocyanate groups at the molecular terminals can be reacted with a chain extender, the remaining isocyanate groups at the molecular terminals can be capped with a terminal-capping agent, and the primary neutralizer can be replaced with a secondary neutralizer and terminal-capping agent. This method can produce an extended / capped hybrid polyurethane resin.

[0112] The polyurethane resin may be used alone or in combination of two or more kinds. As the polyurethane resin, an extended polyurethane resin and a sealed polyurethane resin are preferable, and an extended polyurethane resin is more preferable.

[0113] (1-4) Polyurethane Resin Polyurethane resins (extended polyurethane resins, blocked polyurethane resins, and hybrid extended and blocked polyurethane resins) contain primary or secondary monoamines (secondary neutralizers or end-capping agents) as neutralizing agents.

[0114] More specifically, as described above, the polyurethane resin has anionic groups, which are neutralized with a neutralizing agent, which contains a primary or secondary monoamine (secondary neutralizing agent or end-capping agent).

[0115] The neutralizing agent may contain only a primary or secondary monoamine (secondary neutralizing agent or end-capping agent), or may contain a tertiary monoamine (primary neutralizing agent) and a primary or secondary monoamine (secondary neutralizing agent or end-capping agent). The neutralizing agent preferably contains a tertiary monoamine (primary neutralizing agent) and a primary or secondary monoamine (secondary neutralizing agent or end-capping agent).

[0116] In the neutralizing agent, the ratio of the tertiary monoamine (primary neutralizing agent) to the primary or secondary monoamine (secondary neutralizing agent or end-capping agent) is not particularly limited. Preferably, from the viewpoint of storage stability, the content ratio of the primary or secondary monoamine (secondary neutralizing agent or end-capping agent) is adjusted.

[0117] For example, from the viewpoint of storage stability, the content of the tertiary monoamine (primary neutralizer) relative to the total amount of neutralizer (i.e., the total moles of the tertiary monoamine (primary neutralizer) and the primary and secondary monoamines (secondary neutralizers or end-capping agents)) is, for example, 0 mol % or more, preferably 1 mol % or more, more preferably 5 mol % or more, even more preferably 8 mol % or more, and particularly preferably 10 mol % or more.

[0118] Furthermore, from the viewpoint of storage stability, the content of the tertiary monoamine (primary neutralizer) relative to the total amount of neutralizer (i.e., the total moles of the tertiary monoamine (primary neutralizer) and the primary and secondary monoamines (secondary neutralizers or end-capping agents)) is, for example, 80 mol % or less, preferably 75 mol % or less, more preferably 70 mol % or less, even more preferably 50 mol % or less, still more preferably 30 mol % or less, and particularly preferably 20 mol % or less.

[0119] From the viewpoint of storage stability, the content of the primary or secondary monoamine (secondary neutralizer) relative to the total amount of neutralizer (i.e., the total moles of the tertiary monoamine (primary neutralizer) and the primary or secondary monoamine (secondary neutralizer or end-capping agent)) is, for example, 20 mol % or more, preferably 25 mol % or more, more preferably 30 mol % or more, even more preferably 50 mol % or more, still more preferably 70 mol % or more, and particularly preferably 80 mol % or more.

[0120] From the viewpoint of storage stability, the content of the primary or secondary monoamine (secondary neutralizer) relative to the total amount of neutralizer (i.e., the total moles of the tertiary monoamine (primary neutralizer) and the primary or secondary monoamine (secondary neutralizer or end-capping agent)) is, for example, 100 mol % or less, preferably 99 mol % or less, more preferably 95 mol % or less, even more preferably 92 mol % or less, and particularly preferably 90 mol % or less.

[0121] The content ratio of the primary or secondary monoamine (secondary neutralizer) relative to the total amount of the neutralizer (i.e., the total moles of the tertiary monoamine (primary neutralizer) and the primary or secondary monoamine (secondary neutralizer or end-capping agent)) can be measured in accordance with the examples described later.

[0122] The number average molecular weight of the polyurethane resin is, for example, 500 or more. The number average molecular weight of the polyurethane resin is usually 3,000,000 or less.

[0123] From the viewpoint of water resistance, the number average molecular weight of the polyurethane resin is preferably relatively high. More specifically, the number average molecular weight of the polyurethane resin is preferably 700 or more, preferably 1,000 or more, more preferably 5,000 or more, even more preferably 10,000 or more, and particularly preferably 100,000 or more.

[0124] In other words, from the viewpoint of water resistance, the polyurethane resin is preferably an extended polyurethane resin. The extended polyurethane resin has a relatively high number average molecular weight. The number average molecular weight of the extended polyurethane resin is within the above range. Therefore, the extended polyurethane resin can provide excellent water resistance.

[0125] The concentration of urethane groups and urea groups in the polyurethane resin is, for example, 0.1% by mass or more, and typically 60% by mass or less.

[0126] From the viewpoint of gas barrier properties, the concentration of urethane groups and urea groups in the polyurethane resin is relatively high. For example, when the polyol compound contains a short-chain diol having 2 to 6 carbon atoms and does not contain a high-molecular-weight polyol, the concentration of urethane groups and urea groups in the polyurethane resin becomes relatively high.

[0127] More specifically, the urethane group / urea group concentration of the polyurethane resin is preferably 30% by mass or more, more preferably 32% by mass or more, and even more preferably 33% by mass or more. The urethane group / urea group concentration of the polyurethane resin is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 42% by mass or less. The urethane group / urea group concentration of the polyurethane resin can be calculated from the charging ratio of the raw material components.

[0128] (2) Polyurethane Dispersion As described above, the polyurethane resin (extended polyurethane resin, blocked polyurethane resin, and hybrid extended / blocked polyurethane resin) is obtained as a polyurethane dispersion.

[0129] The solids concentration of the polyurethane dispersion is adjusted by an appropriate method. To adjust the solids concentration of the polyurethane dispersion, water can be removed from the polyurethane dispersion by a known method. In this method, water can be added to the polyurethane dispersion to adjust the solids concentration. In addition, an aqueous solvent (e.g., 2-propanol) can be added to the polyurethane dispersion to adjust the solids concentration.

[0130] The polyurethane dispersion has a solids concentration of, for example, 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more, and for example, 60% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less.

[0131] From the viewpoint of storage stability, the carbonate ion concentration of the polyurethane dispersion is preferably relatively low. For example, the carbonate ion concentration relative to the total amount of the polyurethane dispersion is, for example, 1000 ppm or less, preferably 700 ppm or less, more preferably 500 ppm or less, even more preferably 400 ppm or less, and particularly preferably 300 ppm or less. The carbonate ion concentration relative to the total amount of the polyurethane dispersion is usually 10 ppm or more. The carbonate ion concentration can be measured by quantitative analysis using an electrophoresis system in accordance with the examples described below.

[0132] If the carbonate ion concentration is within the above range, elimination of the neutralizing agent by the carbonate ions can be suppressed, and the generation of free anionic groups and aggregation of the polyurethane resin can be suppressed, thereby improving storage stability.

[0133] The carbonate ion concentration is adjusted by a known method. Preferably, the organic solvent and water are removed by vacuum purging (desolvation), and then the carbon dioxide gas and carbonate ions are removed by continuing vacuum purging (decarbonation).

[0134] The vacuum purging conditions are, for example, a pressure of 1 kPa or more, preferably 2 kPa or more, and for example, 50 kPa or less, preferably 40 kPa or less. The vacuum purging time is, for example, 0.5 hours or more, preferably 1.0 hours or more, more preferably 1.5 hours or more, even more preferably 2.0 hours or more, and particularly preferably 3.0 hours or more. This allows the carbonate ion concentration of the polyurethane dispersion to be adjusted.

[0135] The polyurethane dispersion has a pH of, for example, 5 or more, or preferably 6 or more. The polyurethane dispersion has a pH of, for example, 11 or less, or preferably 10 or less.

[0136] The polyurethane dispersion has an average particle size of, for example, 10 nm or more, preferably 20 nm or more, more preferably 50 nm or more, and for example, 500 nm or less, preferably 300 nm or less, more preferably 200 nm or less, and even more preferably 100 nm or less.

[0137] The polyurethane dispersion may contain various additives as needed. Examples of additives include fillers (e.g., layered inorganic compounds), dispersants, silane coupling agents, alkoxysilane compounds, antioxidants, heat stabilizers, UV absorbers, plasticizers, antistatic agents, lubricants, antiblocking agents, surfactants, dispersion stabilizers, pigments, dyes, and nucleating agents. These may be used alone or in combination of two or more. The amount and timing of addition of the additives are appropriately determined depending on the type of additive.

[0138] The polyurethane dispersion may further contain a curing agent. Examples of the curing agent include epoxy curing agents, melamine curing agents, carbodiimide curing agents, aziridine curing agents, oxazoline curing agents, and isocyanate curing agents. The content of the curing agent is not particularly limited and may be appropriately determined depending on the purpose and application.

[0139] The polyurethane resin and the polyurethane dispersion have excellent storage stability because the neutralizing agent contains a primary or secondary monoamine.

[0140] Furthermore, in the above polyurethane resin, if the polyisocyanate component contains bis(isocyanatomethyl)cyclohexane and / or xylylene diisocyanate and the polyol compound contains a short-chain diol having 2 to 6 carbon atoms, the polyurethane resin will have particularly excellent gas barrier properties.

[0141] Therefore, the polyurethane dispersion is suitable for use as a gas barrier coating material.

[0142] 2. Gas Barrier Coating Material The gas barrier coating material contains the above-mentioned polyurethane dispersion (PUD) and the above-mentioned polyurethane resin (extended polyurethane resin, sealed polyurethane resin, and / or extended / sealed hybrid polyurethane resin).

[0143] The gas barrier coating material may further contain a curing agent. Examples of curing agents include epoxy curing agents, melamine curing agents, carbodiimide curing agents, aziridine curing agents, oxazoline curing agents, and isocyanate curing agents. The content of the curing agent is not particularly limited and may be appropriately determined depending on the purpose and application.

[0144] Preferably, the gas barrier coating material is made of the above polyurethane dispersion (PUD), or made of the above polyurethane dispersion (PUD) and the above curing agent.

[0145] Furthermore, the solids concentration of the gas barrier coating material can be adjusted as needed. For example, to adjust the solids concentration of the gas barrier coating material, water can be removed from the polyurethane dispersion (PUD) by a known method. Furthermore, to adjust the solids concentration of the gas barrier coating material, water can be added to the polyurethane dispersion (PUD).

[0146] The solid content concentration of the gas barrier coating material is, for example, 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more, and for example, 60% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less.

[0147] The gas barrier coating material contains a polyurethane resin, and therefore, the gas barrier coating material can form a coating layer (barrier coating layer) having excellent gas barrier properties.

[0148] 3. Effects and Effects In the polyurethane dispersion and gas barrier coating material described above, the polyurethane resin contains a reaction product of an isocyanate-terminated prepolymer and a chain extender and / or an end-capping agent. The isocyanate-terminated prepolymer contains a reaction product of a polyisocyanate component and an active hydrogen group-containing component. The active hydrogen group-containing component contains a polyol compound and an active hydrogen group-containing compound containing an anionic group. The anionic group is neutralized with a neutralizing agent. The neutralizing agent contains a monoamine compound having a primary amino group or a secondary amino group.

[0149] As a result, the polyurethane dispersion and gas barrier coating material have excellent storage stability.

[0150] In the method for producing the polyurethane dispersion, a polyisocyanate component is first reacted with a polyol compound and an active hydrogen group-containing component containing an active hydrogen group-containing compound having an anionic group to synthesize an isocyanate-terminated prepolymer. The anionic groups are then neutralized with a primary neutralizer containing a monoamine compound having a tertiary amino group. The isocyanate-terminated prepolymer is then reacted with a chain extender to obtain a polyurethane resin. Finally, at least a portion of the primary neutralizer is replaced with a secondary neutralizer containing a monoamine compound having a primary or secondary amino group.

[0151] As a result, the above-described method for producing a polyurethane dispersion makes it possible to produce a polyurethane dispersion having excellent storage stability.

[0152] Furthermore, in the above polyurethane resin, if the polyisocyanate component contains bis(isocyanatomethyl)cyclohexane and / or xylylene diisocyanate and the polyol compound contains a short-chain diol having 2 to 6 carbon atoms, the polyurethane resin will have particularly excellent gas barrier properties. In particular, if the polyol compound does not contain a high-molecular-weight polyol but is composed of a low-molecular-weight polyol, the polyurethane resin will have particularly excellent gas barrier properties.

[0153] As a result, the polyurethane dispersion can be used to produce a polyurethane layer having excellent gas barrier properties.

[0154] On the other hand, when the polyol compound does not contain a high-molecular-weight polyol but is composed of a low-molecular-weight polyol, the concentration of urethane groups and urea groups in the polyurethane resin becomes relatively high as described above. In such cases, aggregation due to the urethane groups and urea groups is likely to occur, and storage stability may be reduced.

[0155] In contrast, the storage stability of the polyurethane dispersion is improved by the addition of a monoamine compound having a primary or secondary amino group, which means that aggregation of the polyurethane resin can be suppressed even when the concentration of urethane groups and urea groups is relatively high.

[0156] That is, the polyurethane dispersion described above can effectively provide excellent storage stability when the urethane group and urea group concentration is relatively high and the polyurethane resin has excellent gas barrier properties.

[0157] Therefore, the polyurethane dispersion and gas barrier coating material can be suitably used in various industrial fields in the production of laminates comprising a substrate and a polyurethane layer.

[0158] 4. Laminate A laminate including a polyurethane layer includes, for example, a substrate and a polyurethane layer disposed on one side of the substrate in the thickness direction.

[0159] Examples of substrates include plastic substrates, fibrous substrates, metal substrates, and ceramic substrates. Preferred substrates include plastic substrates and fibrous substrates. Plastic substrates are, for example, films made of plastic. Examples of plastics include thermoplastic resins and thermosetting resins, preferably thermoplastic resins. Examples of thermoplastic resins include polyolefin resins, polyester resins, polyamide resins, polyvinyl resins, acrylic resins, polycarbonate resins, and cellulose resins. Preferred thermoplastic resins include polyolefin resins and polyester resins. Examples of plastic substrates include unstretched substrates, uniaxially stretched substrates, and biaxially stretched substrates, preferably biaxially stretched substrates. Examples of fibrous substrates include paper, cloth, and wood. These can be used alone or in combination. The substrate may be surface-treated as needed. Examples of surface treatments include vapor deposition, anchor coating, and plasma treatment.

[0160] The thickness of the substrate is, for example, 1 μm or more, or preferably 3 μm or more, and for example, 500 μm or less, or preferably 200 μm or less.

[0161] The polyurethane layer contains a dried product of the polyurethane dispersion, and preferably consists of the dried product of the polyurethane dispersion.

[0162] The polyurethane layer is laminated, for example, on one or both sides of the substrate. Such a laminate can be obtained, for example, by applying the polyurethane dispersion (gas barrier coating material) to one or both sides of the substrate and drying it. The polyurethane layer is preferably a gas barrier layer.

[0163] The method for applying the polyurethane dispersion (gas barrier coating material) is not particularly limited. Examples of application methods include dip coating, gravure coating, reverse coating, roll coating, bar coating, spray coating, and air knife coating. The conditions for drying the polyurethane dispersion (gas barrier coating material) are not particularly limited. For example, the drying temperature is, for example, 40°C or higher, preferably 50°C or higher. The drying temperature is, for example, 200°C or lower, preferably 180°C or lower. The drying time is, for example, 1 second or longer, preferably 30 seconds or longer. The drying time is, for example, 10 minutes or shorter, preferably 5 minutes or shorter.

[0164] By the drying, a polyurethane layer is formed on one or both sides of the substrate. The polyurethane layer is a dried coating film of the polyurethane dispersion. When the polyurethane dispersion is a gas barrier coating material, the polyurethane layer is a dried coating film of the gas barrier coating material and is a barrier coating layer.

[0165] The amount (dry mass) of the polyurethane layer is, for example, 0.1 g / m ２ More than 0.2 g / m ２ The amount (dry mass) of the polyurethane layer is, for example, 10 g / m ２ Preferably, 7 g / m or less ２ The following is the result.

[0166] The polyurethane layer may also be, for example, an anchor coating layer (undercoat layer) for an inorganic vapor deposition layer (metal layer). In other words, the polyurethane dispersion may be an anchor coating agent for an inorganic vapor deposition layer.

[0167] That is, as described above, the substrate may be subjected to a vapor deposition treatment. In other words, the substrate may include a substrate body (e.g., a plastic substrate, a fiber substrate, a metal substrate, or a ceramic substrate) and an inorganic vapor deposition layer.

[0168] In such a case, the polyurethane dispersion is applied to one or both surfaces of the substrate body before the deposition treatment, for example.

[0169] In such cases, a polyurethane layer is formed on one or both sides of the substrate body by drying the polyurethane dispersion, and then an inorganic vapor deposition layer is laminated on the polyurethane layer by a known method.

[0170] According to the above method, a laminate is obtained that includes a substrate body, a polyurethane layer laminated on the substrate body, and an inorganic vapor deposition layer laminated on the polyurethane layer.

[0171] In such a laminate, the polyurethane layer serves as an anchor coating layer (undercoat layer) for the inorganic vapor deposition layer. That is, the laminate includes an anchor coating layer (undercoat layer) made of the polyurethane layer. The polyurethane dispersion serves as an anchor coating agent.

[0172] The amount (dry mass) of the anchor coat layer is, for example, 0.1 g / m ２ More than 0.2 g / m ２ The amount (dry mass) of the anchor coat layer is, for example, 10 g / m ２ Preferably, 7 g / m or less ２ The following is the result.

[0173] The polyurethane layer may also be, for example, an overcoat layer for an inorganic vapor deposition layer, that is, the polyurethane dispersion may be an overcoat agent for an inorganic vapor deposition layer.

[0174] More specifically, the substrate may be subjected to a vapor deposition treatment, and an inorganic vapor deposition layer may be laminated on one or both surfaces of the substrate body. In such cases, the polyurethane dispersion is applied to the surface of the inorganic vapor deposition layer.

[0175] In such cases, a polyurethane layer is formed on the surface of the inorganic vapor deposition layer by drying the polyurethane dispersion.

[0176] According to the above method, a laminate is obtained that includes a substrate body, an inorganic vapor deposition layer laminated on the substrate body, and a polyurethane layer laminated on the inorganic vapor deposition layer.

[0177] In such a laminate, the polyurethane layer serves as an overcoat layer for the inorganic vapor deposition layer. That is, the laminate includes an overcoat layer made of the polyurethane layer. The polyurethane dispersion serves as an overcoat agent.

[0178] The amount (dry mass) of the overcoat layer is, for example, 0.1 g / m ２ More than 0.2 g / m ２ The amount (dry mass) of the overcoat layer is, for example, 10 g / m ２ Preferably, 7 g / m or less ２ The following is the result.

[0179] Furthermore, the laminate may include both the anchor coat layer (undercoat layer) and the overcoat layer.

[0180] More specifically, for example, the polyurethane dispersion is applied to one or both surfaces of a substrate body before vapor deposition and dried to form an anchor coat layer (undercoat layer). Next, the substrate is vapor-deposited by a known method, and an inorganic vapor-deposited layer is laminated on the anchor coat layer (undercoat layer). Thereafter, the polyurethane dispersion is applied to the inorganic vapor-deposited layer, for example, and dried to form an overcoat layer.

[0181] According to the above method, a laminate is obtained which includes a substrate body, an anchor coat layer laminated on the substrate body, an inorganic vapor deposition layer laminated on the anchor coat layer, and an overcoat layer laminated on the inorganic vapor deposition layer.

[0182] Preferably, when the polyurethane resin contained in the polyurethane dispersion has a relatively high concentration of urethane groups and urea groups and has excellent gas barrier properties, the laminate includes the overcoat layer and / or the anchor coat layer, and such a laminate has particularly excellent gas barrier properties.

[0183] Furthermore, such a laminate has excellent productivity because it is produced using the polyurethane dispersion having excellent storage stability.

[0184] In a laminate including a polyurethane layer, a sealing layer can be formed between the substrate and the polyurethane layer as needed. For example, when the substrate is paper, a sealing coating material (e.g., an acrylic coating material) is preferably applied to at least one side of the paper and dried to form the sealing layer in order to prevent the polyurethane dispersion from penetrating into the substrate. In addition, a functional layer can be formed on the surface of the polyurethane layer as needed. Examples of functional layers include a design layer, a surface protection layer, and a heat-sealing layer, and a preferred example is the heat-sealing layer. The heat-sealing layer is not particularly limited and is formed from a known heat-sealing coating material.

[0185] The total thickness of the laminate is, for example, 5 μm or more, or preferably 10 μm or more, and for example, 1 mm or less, or preferably 0.5 mm or less.

[0186] Such a laminate can be suitably used, for example, in the production of food packaging materials.

[0187] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Note that "parts" and "%" are by mass unless otherwise specified. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be substituted with the corresponding upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or more than" or "exceeding") of the blending ratios (content ratios), physical property values, parameters, etc. described in the above "Modes for Carrying Out the Invention."

[0188] 1. Raw Materials <High Molecular Weight Polyol (Polyester Polyol)> Preparation Example 1 228.9 parts by mass of isophthalic acid, 46.4 parts by mass of ethylene glycol, and 263.3 parts by mass of neopentyl glycol were subjected to an esterification reaction at 180 to 220° C. in a nitrogen stream.

[0189] A predetermined amount of water was distilled from the reaction product of the esterification reaction. Then, 278.7 parts by mass of sebacic acid was added to the reaction product, and the mixture was subjected to an esterification reaction at 180 to 220° C. This yielded a polyester polyol having a number average molecular weight of approximately 2,500.

[0190] <Nonionic Side Chain-Containing Diol> Preparation Example 2 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube was charged with 1,000 parts by mass of methoxypolyethylene glycol (number average molecular weight 1,000, manufactured by Toho Chemical Industry Co., Ltd.) and 1,682 parts by mass of 1,6-hexamethylene diisocyanate (manufactured by Mitsui Chemicals, Inc.), and these were reacted for 9 hours at 90°C under a nitrogen atmosphere. The reaction product liquid from the above reaction was subjected to thin-film distillation to remove unreacted 1,6-hexamethylene diisocyanate. This yielded a monoisocyanate containing a polyoxyethylene group capped at one end with methoxy groups.

[0191] A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube was charged with 82.5 parts by mass of diethanolamine. While the contents of the flask were air-cooled, 917.5 parts by mass of the monoisocyanate containing a methoxy-terminated polyoxyethylene group was added dropwise to the flask under a nitrogen atmosphere. During the dropwise addition, the temperature of the contents of the flask was adjusted to less than 70°C. After the dropwise addition, the contents of the flask were stirred at 70°C under a nitrogen atmosphere for approximately 1 hour. It was also confirmed that the isocyanate groups in the contents of the flask had disappeared. This yielded a diol containing a methoxy-terminated polyoxyethylene side chain.

[0192] 2. Polyurethane Dispersion <Extended Polyurethane Resin> Examples 1 to 9 (PUDs 1 to 9), Examples 11 to 24 (PUDs 11 to 24), and Comparative Examples 1 and 2 (PUDs 25 to 26) [i] Prepolymer Synthesis Step A polyisocyanate component, an active hydrogen group-containing component, and an organic solvent were mixed according to the formulations shown in Tables 1 to 3, and the mixture was reacted under a nitrogen atmosphere at 65 to 70°C. The reaction was continued until the isocyanate group concentration in the reaction solution reached the predetermined value shown in the table. This yielded a reaction solution containing an isocyanate group-terminated prepolymer. The reaction solution was cooled to 40°C.

[0193] [ii] Neutralization Step Next, the isocyanate group-terminated prepolymer was neutralized by adding a primary neutralizer shown in Tables 1 to 3 to the reaction solution. Trimethylamine (TMA) was dissolved in acetonitrile and used as a trimethylamine solution (concentration: 13% by mass).

[0194] [iii] Chain Extension Step Next, the neutralized isocyanate-terminated prepolymer was dispersed in ion-exchanged water using a Homodisper, thereby obtaining a dispersion of an isocyanate-terminated prepolymer.

[0195] Next, a chain extender solution was obtained by dissolving a chain extender in ion-exchanged water according to the formulation shown in Tables 1 to 3. The chain extender solution was added to the dispersion of the isocyanate-terminated prepolymer, and the isocyanate-terminated prepolymer was subjected to a chain extension reaction for 1 hour. This resulted in an extended polyurethane resin.

[0196] Next, the organic solvent and ion-exchanged water were distilled off from the reaction solution using an evaporator at a water bath temperature of 50° C. under reduced pressure.

[0197] In Examples 1 to 9, Examples 12 to 24, and Comparative Examples 1 and 2, the depressurization time was set to 4 to 5 hours. This resulted in the removal (decarbonation) of carbonate ions from the reaction solution. On the other hand, in Example 11, the depressurization time was set to 1 hour. In other words, the carbonate ions from the reaction solution were not sufficiently removed (decarbonated).

[0198] [iv] Substitution Step: Ion-exchanged water was then added to the reaction solution to adjust the solid content to 30% by mass, thereby obtaining a primary polyurethane dispersion (primary PUD).

[0199] Next, the temperature of the primary polyurethane dispersion (primary PUD) was adjusted to 40°C. Next, a secondary neutralizer listed in Tables 1 to 3 was added to the primary polyurethane dispersion (primary PUD), and the primary polyurethane dispersion (primary PUD) was stirred at 40°C and atmospheric pressure for 30 minutes. This resulted in a partial substitution of the primary neutralizer with the secondary neutralizer. This resulted in a substitution treatment liquid. Next, an evaporator was used to distill off the free primary neutralizer, the free secondary neutralizer, and a portion of the ion-exchanged water from the substitution treatment liquid. Furthermore, ion-exchanged water was added to the substitution treatment liquid as needed, and the solids concentration of the substitution treatment liquid was adjusted to 30% by mass.

[0200] Furthermore, in Examples 21 to 23, after the above-mentioned substitution (first substitution) and distillation (first distillation), a secondary neutralizing agent shown in Tables 1 to 3 was further added to the substitution treatment liquid having a solids concentration of 30% by mass, and the substitution treatment liquid was stirred at 40°C and atmospheric pressure for 30 minutes. This resulted in a further substitution of a portion of the primary neutralizing agent with the secondary neutralizing agent. Next, an evaporator was used to distill off the free primary neutralizing agent, the free secondary neutralizing agent, and a portion of the ion-exchanged water from the substitution treatment liquid. Furthermore, ion-exchanged water was added to the substitution treatment liquid as needed to adjust the solids concentration of the substitution treatment liquid to 30% by mass.

[0201] In Comparative Examples 1 and 2, no secondary neutralizing agent was added.

[0202] That is, in Examples 1 to 9, 11 to 20, and 24, a portion of the primary neutralizer was replaced with a secondary neutralizer once. In Examples 21 to 23, a portion of the primary neutralizer was replaced with a secondary neutralizer twice. On the other hand, in Comparative Examples 1 and 2, a portion of the primary neutralizer was not replaced with a secondary neutralizer.

[0203] This resulted in a secondary polyurethane dispersion containing an extended polyurethane resin, which was used as a gas barrier coating material.

[0204] <Sealed Polyurethane Resin> Example 10 (PUD10) [i] Prepolymer Synthesis Step A polyisocyanate component, an active hydrogen group-containing component, and an organic solvent were mixed according to the formulations shown in Tables 1 to 3, and the mixture was reacted under a nitrogen atmosphere at 65 to 70°C. The reaction was continued until the isocyanate group concentration in the reaction solution reached the predetermined value shown in the table. This yielded a reaction solution containing an isocyanate group-terminated prepolymer. The reaction solution was cooled to 40°C.

[0205] [ii] Neutralization Step Next, a neutralizing agent shown in Tables 1 to 3 was added to the reaction solution to neutralize the isocyanate group-terminated prepolymer.

[0206] [iii] Capping and Substitution Step Next, the neutralized isocyanate-terminated prepolymer was dispersed in ion-exchanged water using a Homodisper, thereby obtaining a dispersion of an isocyanate-terminated prepolymer.

[0207] Next, a terminal blocking agent was added to the dispersion of the isocyanate group-terminated prepolymer in accordance with the formulation shown in Tables 1 to 3, and the isocyanate group-terminated prepolymer was subjected to a terminal blocking reaction for 1 hour.

[0208] In addition, during the end-capping reaction, a portion of the primary neutralizer was replaced with an end-capping agent, thereby obtaining a blocked polyurethane resin.

[0209] Next, the organic solvent and ion-exchanged water were distilled off from the reaction solution using an evaporator under reduced pressure at a water bath temperature of 50°C. The reduced pressure time was set to 4 to 5 hours. This removed carbonate ions (decarbonation) from the reaction solution.

[0210] Thereafter, ion-exchanged water was added to the reaction liquid to adjust the solid content to 30% by mass, thereby obtaining a polyurethane dispersion containing a sealed polyurethane resin.

[0211] 3. Measurement of Physical Properties (1) Urethane and Urea Group Concentration The urethane and urea group concentrations of the polyurethane resin were calculated based on the charge ratio of the raw material components.

[0212] (2) Average Particle Diameter The average particle diameter of the polyurethane dispersion immediately after production was measured using a concentrated particle size analyzer FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

[0213] (3) Content of Primary and Secondary Monoamines <Primary and Secondary Monoamine Concentration (% by mass) and Tertiary Monoamine Concentration (% by mass)> A gas chromatogram of the polyurethane dispersion was obtained under the following gas chromatograph (GC) analysis conditions.

[0214] Gas chromatograms of primary and secondary monoamines and tertiary monoamines were obtained under the following gas chromatograph (GC) analysis conditions. Calibration curves of primary and secondary monoamines and tertiary monoamines were prepared from the area values ​​of the gas chromatograms.

[0215] Based on the gas chromatogram of the polyurethane dispersion and the calibration curve, the concentrations (mass%) of primary and secondary monoamines and the concentration (mass%) of tertiary monoamine in the polyurethane resin were calculated.

[0216] <Gas chromatograph (GC) analysis conditions> Sample concentration: 10% by mass (diluted with ion-exchanged water) Apparatus: Nexis GC-2030 (Shimadzu Corporation) Column: DB-5 (Agilent Technologies) Oven temperature: After holding at 50°C for 5 minutes, increase the temperature from 50°C to 250°C at a rate of 10°C / min Injection port temperature: 250°C Detector temperature: 260°C Carrier gas: Helium Detection method: FID

[0217] (4) Primary and secondary monoamines / neutralizing agent (mol %) The content of primary and secondary monoamines in the neutralizing agent (primary and secondary monoamines / neutralizing agent, mol %) was calculated using the following formula.

[0218] Content (mol %) of primary and secondary monoamines in neutralizing agent = 100 × [concentration of primary and secondary monoamines (mass %) / molecular weight of primary and secondary monoamines] / [(concentration of primary and secondary monoamines (mass %) / molecular weight of primary and secondary monoamines) + (concentration of tertiary monoamines (mass %) / molecular weight of tertiary monoamine)]

[0219] (5) Number-average molecular weight of polyurethane resin 0.1 g of polyurethane dispersion was dissolved in 10 mL of dimethylacetamide (DMAc) as an eluent to obtain a sample solution. The sample solution was allowed to stand overnight. The sample solution was filtered through a 0.45 μm membrane filter to obtain a filtrate.

[0220] The filtrate was subjected to gel permeation chromatography (GPC) measurement under the following GPC measurement conditions to determine the number average molecular weight (polystyrene equivalent).

[0221] <Gel permeation chromatography (GPC) measurement conditions> Analytical device: TOSOH HLC-8320GPC+UV-8320 Analytical device: TOSOH GPC Work station EcoSEC-WS Column: TOSOH TSK-GEL TSK gel α-M Column No. G0032+G0033 Eluent: 0.01 mol-LiBr / 1000 ml-DMAc (N,N-dimethylacetamide) Detector: RI 40°C Column temperature: 40°C Flow rate: 0.6 mL / min Injection volume: 100 μL

[0222] (6) Carbonate Ion Concentration (ppm) The carbonate ion concentration in the polyurethane dispersion was determined using an electrophoresis system.

[0223] Specifically, a polyurethane dispersion sample was weighed and dispensed. The sample was appropriately diluted and dissolved with ultrapure water to prepare a quantitative sample solution. The quantitative sample solution and standard solution were then measured using the following electrophoresis system and measurement conditions. A sample measurement solution was also prepared by adding a standard solution of a known concentration. An addition recovery test was then performed. The carbonate ion concentration relative to the total amount of polyurethane dispersion was then determined using the one-point calibration curve method.

[0224] <Electrophoresis system and measurement conditions> Apparatus: 7100 Capillary Electrophoresis System manufactured by Agilent Technologies Buffer: Harmful Anion Analysis Buffer manufactured by Agilent Technologies

[0225] 4. Evaluation (1) Storage Stability The polyurethane dispersion was stored for 28 days at 60° C. Thereafter, the average particle size of the polyurethane dispersion after storage was measured using a concentrated particle size analyzer FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

[0226] The rate of increase in the average particle size (D2) of the polyurethane dispersion after storage relative to the average particle size (D1) of the polyurethane dispersion immediately after production was calculated using the following formula: Furthermore, the storage stability was evaluated based on the rate of increase in the average particle size according to the following criteria.

[0227] Increase rate (%) of average particle diameter = 100 × average particle diameter after storage (D2) / average particle diameter immediately after production (D1)

[0228] 5: The increase rate of the average particle size is less than 150%. 4: The increase rate of the average particle size is 150% or more but less than 200%. 3: The increase rate of the average particle size is 200% or more but less than 250%. 2: The increase rate of the average particle size is 250% or more but less than 300%. 1: The increase rate of the average particle size is 300% or more.

[0229] (2) Water Resistance A polyethylene terephthalate film (biaxially oriented polyester film, product name: Toyobo Ester Film E5102, manufactured by Toyobo Co., Ltd., thickness 12 μm) was prepared as a substrate. A polyurethane dispersion was applied to the substrate using a bar coater. The amount of coating was 3 g / m2, and the coating thickness after drying was 3 g / m2. ２ It was adjusted so that

[0230] The substrate coated with the polyurethane dispersion was then dried for 1 minute in a drying oven at 110° C. This resulted in a laminate comprising the substrate and the polyurethane layer.

[0231] Thereafter, the polyurethane layer was rubbed with a cotton swab moistened with water. The number of times the polyurethane layer was rubbed until the polyurethane layer peeled off from the substrate was recorded. Note that if the polyurethane layer did not peel off even after rubbing 10 times, the number of times the polyurethane layer was rubbed was recorded as 10.

[0232] 5. Anchor Coating Agent Preparation Examples AC1 to AC6 According to the information in Table 4, water and an aqueous solvent were added to PUD23 of Example 23 to adjust the solids concentration. If necessary, a curing agent was also added. In this way, anchor coating agents (AC) were prepared.

[0233] 6. Overcoat Agent Preparation Examples OC1 to OC6 According to the information in Table 4, water and an aqueous solvent were added to PUD23 of Example 23 to adjust the solids concentration. If necessary, a curing agent was also added. In this way, overcoat agents (OC) were prepared.

[0234] 7. Laminate 1 Examples 26 to 31 Laminates were obtained according to the description in Table 4. More specifically, first, a polyolefin substrate (substrate body) was prepared according to the description in Table 4.

[0235] Next, according to the description in Table 4, an anchor coating agent was applied to one side of a biaxially oriented polypropylene film (hereinafter referred to as a polyolefin substrate (substrate body)) using a bar coater. The anchor coating agent was then dried at 80°C for 1 minute. This formed a polyurethane layer (anchor coating layer) on the surface of the polyolefin substrate. The dry mass (g / m ２ The amount of anchor coating agent applied was adjusted so that the values ​​shown in Table 4 were obtained.

[0236] Thereafter, the polyolefin substrate (substrate body) and the polyurethane layer (anchor coat layer) were set in a vacuum deposition apparatus (manufactured by ULVAC). Then, aluminum, aluminum oxide, or silicon oxide was deposited (1 × 10) on the surface of the polyurethane layer (anchor coat layer) according to the description in Table 4. －４ The inorganic vapor deposition layer was formed by subjecting the substrate to a vacuum of 0.2 Pa and a RH system.

[0237] The inorganic vapor deposition layer made of aluminum (AL) had a thickness of 50 nm, the inorganic vapor deposition layer made of aluminum oxide (AlOx) had a thickness of 20 nm, and the inorganic vapor deposition layer made of silicon oxide (SiOx) had a thickness of 30 nm.

[0238] Thereafter, an overcoat agent was applied using a bar coater according to the description in Table 4. The overcoat agent was then dried at 80°C for 1 minute. This resulted in the formation of a polyurethane layer (overcoat layer) on the surface of the inorganic vapor deposition layer. The dry mass (g / m ２ The amount of the overcoat agent applied was adjusted so that the values ​​shown in Table 4 were obtained.

[0239] As a result of the above, a laminate 1 was obtained, which included a polyolefin substrate, a polyurethane layer (anchor coat layer) disposed on the polyolefin substrate, an inorganic vapor deposition layer disposed on the polyurethane layer (anchor coat layer), and / or a polyurethane layer (overcoat layer) disposed on the inorganic vapor deposition layer.

[0240] In Examples 26 to 31, the layer structure of the laminate 1 was as follows: Laminate 1: polyolefin substrate / anchor coat layer / inorganic vapor deposition layer / overcoat layer

[0241] Example 32: Water and an aqueous solvent were added to PUD23 of Example 23 to adjust the solids concentration according to the information in Table 5. If necessary, a curing agent was added. This gave a gas barrier coating material.

[0242] A laminate was obtained according to the description in Table 5. More specifically, first, a polyolefin substrate (substrate body) was prepared according to the description in Table 5.

[0243] Next, a gas barrier coating material was applied to one side of the polyolefin substrate (substrate body) using a bar coater according to the description in Table 4. The gas barrier coating material was then dried at 80°C for 1 minute. This formed a polyurethane layer (gas barrier layer) on the surface of the polyolefin substrate. The dry mass (g / m ２ The amount of the gas barrier coating material applied was adjusted so that the values ​​shown in Table 5 were obtained.

[0244] As a result of the above, a laminate 1 was obtained which included a polyolefin substrate and a polyurethane layer (gas barrier layer) disposed on the polyolefin substrate.

[0245] In Example 32, the layer structure of Laminate 1 was as follows: Laminate 1: Polyolefin substrate / gas barrier layer

[0246] 8. Evaluation of Laminate 1 The gas barrier properties and adhesion of Laminate 1 were evaluated by the following methods. The results are shown in Tables 4 and 5.

[0247] (1) Laminate film A polyurethane adhesive was applied to the inorganic vapor deposition layer of the laminate to a dry thickness of 3.0 g / m ２ The polyurethane adhesive was a mixture of the following base agent, curing agent, and ethyl acetate. More specifically, ethyl acetate was added to the mixture of base agent and curing agent to adjust the solid content of the mixture to 25% by mass. Base agent: Takelac A-626, manufactured by Mitsui Chemicals, Inc., 8.0 parts by mass Curing agent: Takenate A-50, manufactured by Mitsui Chemicals, Inc., 1.0 part by mass

[0248] Next, an unstretched polypropylene film (CPP, Tocello CP RXC-22, #60, manufactured by Mitsui Chemicals Tocello Co., Ltd.) was laminated onto the surface coated with the polyurethane adhesive, and aged at 40° C. for 3 days, thereby obtaining a laminate film.

[0249] (2) Gas barrier property Oxygen permeability of laminate film (cc / m ２ The oxygen permeability (day·atm) was measured in accordance with JIS K7126-2 (2006) under the following conditions: Apparatus: Oxygen permeability measuring apparatus, product name OX-TRAN2 / 20, manufactured by MOCON Corporation Temperature: 20°C Humidity: 80% RH

[0250] Next, the laminate film was subjected to a hot water treatment by immersing it in hot water at 121° C. for 30 minutes, after which the oxygen permeation rate of the hot water-treated laminate film was measured under the above-mentioned conditions.

[0251] Thereafter, the rate of increase in oxygen transmission rate was calculated using the following formula: Note that a higher rate of increase in oxygen transmission rate indicates a lower evaluation of hot water resistance.

[0252] Increase rate of oxygen permeability (%) = [(oxygen permeability after hot water treatment - oxygen permeability before hot water treatment) / oxygen permeability before hot water treatment]

[0253] (3) Adhesion

[0254] The lamination strength of the laminate film was measured by a T-peel test (15 mm width) in accordance with JIS K 6854 (1999).

[0255] More specifically, first, a biaxially oriented polypropylene film (bottom layer, substrate body, BOPP) and an unstretched polypropylene film (top layer, CPP) were gripped and pulled in opposite directions to expose the interface between the biaxially oriented polypropylene film (substrate body) and the polyurethane layer (anchor coat layer). Next, a T-peel test was performed to measure the peel strength (lamination strength) of the interface between the biaxially oriented polypropylene film (substrate body) and the polyurethane layer (anchor coat layer).

[0256] Next, the laminate film was subjected to a hot water treatment by immersing it in hot water at 121° C. for 30 minutes, and then the peel strength (lamination strength) of the hot water treated laminate film was measured under the same conditions as above.

[0257] 9. Laminate 2 (1) Paper Base Material As the paper base material, one-sided gloss (bleached) kraft paper (product name: Hakugin, manufactured by Nippon Paper Industries Co., Ltd., basis weight 67 g / m ２ ) was prepared.

[0258] (2) Filling Coating Material A reaction vessel equipped with a stirrer, a reflux condenser, a dropping device, and a thermometer was charged with 2,193 parts by mass of ion-exchanged water (solvent) and 2.5 parts by mass of sodium dodecyl sulfate (surfactant). The contents of the reaction vessel were heated to 75°C while stirring and purging with nitrogen.

[0259] While maintaining the internal temperature of the reaction vessel at 75° C., 7.5 parts by mass of potassium persulfate (polymerization initiator) was added to the reaction vessel and dissolved in the contents of the reaction vessel. Thereafter, a monomer emulsion prepared in advance was continuously added dropwise to the reaction vessel over a period of 5 hours.

[0260] The monomer emulsion is a raw material composition containing the following components: Ion-exchanged water (solvent) 900 parts by mass Sodium dodecyl sulfate (surfactant) 5 parts by mass Acrylamide (raw material monomer) 25 parts by mass Methyl methacrylate (raw material monomer) 175 parts by mass 2-ethylhexyl acrylate (raw material monomer) 1088 parts by mass Methacrylic acid (raw material monomer) 80 parts by mass Styrene (raw material monomer) 1133 parts by mass

[0261] After the dropwise addition of the monomer emulsion was completed, the contents of the reaction vessel were aged for 3 hours. This allowed the raw material monomers to polymerize, yielding a (meth)acrylic resin. Also, an acrylic emulsion in which the (meth)acrylic resin was dispersed in water was obtained.

[0262] The acrylic emulsion was cooled to room temperature, and then ion-exchanged water and ammonia water (neutralizer) were added to the acrylic emulsion to adjust the solid content to 41% by mass and the pH to 8.0.

[0263] This resulted in an acrylic emulsion in which the (meth)acrylic resin was dispersed in water. The average particle size of the acrylic emulsion was 140 nm. The average particle size was measured by dynamic light scattering (using a measuring device FPAR-1000 manufactured by Otsuka Electronics Co., Ltd.).

[0264] Thereafter, water was further added to the above acrylic emulsion (solid content concentration 41% by mass), and the mixture was mixed for 5 minutes using a mixer to prepare a sealing coating material (solid content concentration 40% by mass).

[0265] (3) Gas Barrier Coating Material Preparation Example BC1 28.8 parts by mass of a dispersion of a swellable layered inorganic compound (product name: ME300-B4T, synthetic mica, manufactured by Katakura Co-op Agri Co., Ltd., solids concentration 7.8%), 42.5 parts by mass of PUD23 of Example 23, and 28.7 parts by mass of ion-exchanged water were mixed in a mixer for 5 minutes. This gave a gas barrier coating material (BC) with a solids concentration of 15% by mass.

[0266] Preparation Example BC2 22.5 parts by mass of a dispersion of a swellable layered inorganic compound (NTS-10NC, manufactured by Topy Industries, Ltd., solids concentration 10% by mass), 42.5 parts by mass of Example 23, and 35.0 parts by mass of ion-exchanged water were mixed in a mixer for 5 minutes to obtain a gas barrier coating material (BC) with a solids concentration of 15% by mass.

[0267] (4) Heat-sealable coating material 50 parts by mass of ethylene-acrylic acid copolymer and 50 parts by mass of ethylene-isobutyl acrylate-methacrylic acid copolymer were melt-kneaded to obtain a resin composition (anionic group-containing polyolefin resin).

[0268] The content of structural units derived from ethylene relative to the total amount of the ethylene-acrylic acid copolymer was 79.5% by mass, and the content of structural units derived from acrylic acid was 20.5% by mass.

[0269] Furthermore, relative to the total amount of the ethylene-isobutyl acrylate-methacrylic acid copolymer, the content of structural units derived from ethylene was 80.0% by mass, the content of structural units derived from isobutyl acrylate was 10.0% by mass, and the content of structural units derived from methacrylic acid was 10.0% by mass.

[0270] The above resin composition, 4.0 parts by mass of potassium hydroxide (neutralizing agent), and 140 parts by mass of deionized water were placed in a reaction vessel and stirred. The contents of the reaction vessel were heated to 150°C and kept at that temperature for 4 hours. This neutralized the resin composition with potassium hydroxide (neutralizing agent). Thereafter, the contents of the reaction vessel were cooled to room temperature.

[0271] As a result, a heat-sealable coating material having a solid content of 42% by mass was obtained.

[0272] (5) Laminate 2 Examples 33 to 34 According to the description in Table 6, laminate 2 was obtained.

[0273] That is, the sealing coating material was applied to the glossy side of a paper substrate (one-sided glossy kraft paper) using a bar coater. ２The coating amount was adjusted so that the coating film of the filler coating material was then dried at 120° C. for 60 seconds, thereby forming a filler layer.

[0274] Next, the gas barrier coating material shown in Table 6 was applied to the surface of the filling layer using a bar coater. ２ The coating amount was adjusted so that the coating film of the gas barrier coating material was 120°C for 60 seconds. As a result, a gas barrier layer was formed on the surface of the filling layer.

[0275] Thereafter, the heat-sealable coating material shown in Table 6 was applied to the surface of the gas barrier layer using a bar coater. ２ The amount of coating was adjusted so that the coating film of the heat-sealable coating material was 100%. The coating film of the heat-sealable coating material was then dried at 120°C for 60 seconds. This resulted in a heat-sealable layer being formed on the surface of the gas barrier layer. In this way, Laminate 2 was obtained.

[0276] In Examples 33 and 34, the layer structure of Laminate 2 was as follows: Laminate 2: Paper base material / filler layer / gas barrier layer / heat seal layer

[0277] The dry mass of the filling layer was calculated by subtracting the mass of the paper substrate from the total mass of the laminate (two layers) including the paper substrate and the filling layer.

[0278] The dry mass of the gas barrier layer was calculated by subtracting the total mass of the laminate (two layers) comprising the paper substrate and the filling layer from the total mass of the laminate (three layers) comprising the paper substrate, the filling layer, and the gas barrier layer.

[0279] The dry mass of the heat seal layer was calculated by subtracting the total mass of the laminate (3 layers) comprising the paper substrate, the sealing layer, and the gas barrier layer from the total mass of the laminate (4 layers) comprising the paper substrate, the sealing layer, the gas barrier layer, and the heat seal layer.

[0280] 10. Evaluation of Laminate 2 (Paper Base) The oxygen transmission rate, water vapor transmission rate, and heat seal strength of Laminate 2 were evaluated by the following methods. The results are shown in Table 6. (1) Oxygen transmission rate (OTR) of Laminate 2: Oxygen transmission rate (cc / m ２ The oxygen permeability (°C) and relative humidity (RH%) were measured using an oxygen permeability measuring device (MOCON, OX-TRAN 2 / 22H). The measurement conditions (temperature (°C) and relative humidity (RH%)) are shown in Table 6.

[0281] (2) Water Vapor Transmission Rate (WVTR) of Laminate 2 ２ The water vapor transmission rate (day) was measured using a water vapor transmission rate measuring device (MOCON, PARMATRAN-W 3 / 34 G). The measurement conditions (temperature (°C) and relative humidity (RH%)) are shown in Table 6.

[0282] (3) Heat-seal strength Two of each laminate 2 were prepared. The heat-seal layers of the two laminates were brought into contact with each other, and they were subjected to heat-sealing at 140°C for 1 second and 2 kg / cm. ２ The heat seal strength (kg / 15 mm) was measured using a tensile device (product number 201X) manufactured by Intesco.

[0283]

[0284]

[0285]

[0286]

[0287]

[0288]

[0289] Details of the abbreviations in the table are as follows: PUD: polyurethane dispersion (including secondary polyurethane dispersion) m-XDI: 1,3-xylylene diisocyanate H １２ MDI: Methylenebis(cyclohexylisocyanate) HDI: Hexamethylene diisocyanate ６XDI: bis(isocyanatomethyl)cyclohexane D-400: trade name Actocol D-400, polyoxypropylene glycol, number average molecular weight 400 (low molecular weight polyol), manufactured by Mitsui Chemicals & SKC Polyurethanes UH200: trade name ETERNACOLL UH-200, polycarbonate diol, number average molecular weight 2000 (high molecular weight polyol), manufactured by Ube Industries MEK: methyl ethyl ketone AN: acetonitrile TEA: triethylamine C: total number of carbon atoms in hydrocarbon groups bonded to primary amino groups or secondary amino groups KBE-903: 3-aminopropyltriethoxysilane, manufactured by Shin-Etsu Silicones BOPP: polyolefin base material, biaxially oriented polypropylene film, trade name Pylen Film OT P2171, thickness 30 μm, manufactured by Toyobo AL: aluminum AlOx: aluminum oxide SiOx: silicon oxide KBM-403: Trade name, epoxy curing agent, 3-glycidoxypropyltrimethoxysilane, silane coupling agent containing an epoxy group, manufactured by Shin-Etsu Chemical Co., Ltd. Carbodilite SV-02: Trade name, carbodiimide curing agent, solid content concentration 40 mass%, manufactured by Nisshinbo Chemical Co., Ltd. Bayhydur 3100: Trade name, isocyanate curing agent, manufactured by BASF Corporation

[0290] The above invention is provided as an exemplary embodiment of the present invention, but it is merely an example and should not be interpreted as being limiting. Modifications of the present invention that are obvious to those skilled in the art are intended to be included in the scope of the following claims.

[0291] The polyurethane dispersion, gas barrier coating material, and method for producing the polyurethane dispersion of the present invention are suitably used in the production of laminates.

Claims

DEPCT681. Polyurethane dispersion comprising: polyurethane resin, in which the polyurethane resin contains the reaction products of isocyanate end-group prepolymers with chain extenders and / or end-group fillers, in which the isocyanate end-group prepolymers contain the reaction products of polyisocyanate components with hydrogenated components, in which the hydrogenated components contain polyol compounds and hydrogenated compounds.

1. Polyurethane dispersion according to claim 1, in which the anionic group is neutralized by a neutralizing agent, and in which the neutralizing agent consists of a monoamine compound with a primary or secondary amino group.

2. Polyurethane dispersion according to claim 1, in which the monoamine compound has a total number of hydrocarbon carbon atoms bonded to primary and secondary amine groups of 2-6.

3. Polyurethane dispersion according to claim 1, in which the polyurethane resin has an average molecular weight of 700 or more. 4.Polyurethane dispersion according to claim 1, where the polyurethane dispersion has a carbonate ion concentration of 700 parts per million or less.

5. Polyurethane dispersion according to claim 1, where the anionic group is a carboxylic acid.

6. Polyurethane dispersion according to claim 1, where the ratio of the amount of monoamine compounds containing primary or secondary amino groups is 25% by mol or more compared to the total moles of the neutralizing agent.

7. Polyurethane dispersion. Under claim 1, where polyisocyanate compounds consist of bis(isocyanatetomethyl)cyclohexane and / or xylylene diisocyanate, and where polyol compounds consist of short-chain diols with 2 to 6 carbon atoms.

8. Polyurethane dispersions under claim 1, where polyurethane resins have a urethane and urea concentration of 33% by mass or more and 42% by mass or less.

9. Gas barrier coatings composed of: polyurethane dispersions under claim 7. 10.The method for producing polyurethane dispersions containing polyurethane resin includes: a prepolymerization step involving the reaction of polyisocyanate components with hydrogen-active polyol compounds and anionic hydrogen-active compounds to synthesize isocyanate prepolymers; a neutralization step, following the prepolymerization step, where the anions are neutralized by a primary neutralizer consisting of monoamine compounds with tertiary amino groups; a chain extension step, following the neutralization step, where the isocyanate prepolymers are reacted with a chain extender to obtain polyurethane resin; and a replacement step, following the chain extension step, where at least part of the primary neutralizer is replaced by a secondary neutralizer consisting of monoamine compounds with primary or secondary amino groups.