Printing primers and laminates

Abstract

To provide a primer for printing which enables formation of a primer layer that is excellent in stability to cationic properties and adhesion, and a laminate obtained using the primer for printing.SOLUTION: A primer for printing is a polyurethane dispersion which contains a polyurethane resin that is a reaction product of an isocyanate group-terminated prepolymer that is a reaction product of a polyisocyanate component and a polyol component containing macropolyol and an active hydrogen group-containing compound having a polyoxyethylene group, and a chain extender. A content of the polyoxyethylene group to the polyurethane resin is 5 mass% or more and 30 mass% or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a printing primer and a laminate, and more particularly to a printing primer used as a primer for a printed layer containing ink, and a laminate obtained by using this printing primer. [Background technology]

[0002] 2. Description of the Related Art Conventionally, when a printed layer containing ink is disposed on a substrate, it is known to dispose a primer layer between the substrate and the printed layer from the viewpoint of adhesion.

[0003] As such a primer layer, for example, a primer layer obtained using an aqueous resin composition containing a urethane resin obtained by reacting tolylene diisocyanate with a polyol containing an aromatic polyester polyol and 2,2-dimethylolpropionic acid, and an aqueous medium, has been proposed (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-189567 A Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, since the ink has cationic properties, the primer layer is required to have stability against cationic properties.

[0006] The primer layer of Patent Document 1 uses a polyol containing 2,2-dimethylolpropionic acid (a polyol having an anionic group), and therefore has the disadvantage of reduced stability against cationic properties.

[0007] Furthermore, the primer layer is required to have adhesion to the substrate.

[0008] The present invention provides a printing primer capable of forming a primer layer having excellent stability against cationic properties and excellent adhesion, and a laminate obtained by using the printing primer. [Means for solving the problem]

[0009] The present invention [1] is a printing primer comprising a polyurethane dispersion containing a polyurethane resin which is a reaction product of an isocyanate-terminated prepolymer, which is a reaction product of a polyisocyanate component and a polyol component containing a macropolyol and an active hydrogen group-containing compound containing a polyoxyethylene group, and a chain extender, and the content of polyoxyethylene groups in the polyurethane resin is 5% by mass or more and 30% by mass or less.

[0010] The present invention [2] includes the printing primer according to the above [1], in which the degree of polymerization of the polyoxyethylene unit in the active hydrogen group-containing compound containing the polyoxyethylene group is 10 or more.

[0011] The present invention [3] includes the printing primer according to the above [1] or [2], in which the isocyanate-terminated prepolymer has a branched structure.

[0012] The present invention [4] includes the printing primer according to any one of the above [1] to [3], in which the polyisocyanate component includes an aliphatic polyisocyanate and / or an alicyclic polyisocyanate.

[0013] The present invention [5] includes the printing primer according to any one of the above [1] to [4], in which the macropolyol is a polyester polyol.

[0014] The present invention [6] includes the printing primer according to the above [5], in which the polyester polyol is a polymerization product of a polybasic acid and a polyhydric alcohol, the polybasic acid includes an aromatic dicarboxylic acid, and the blending ratio of the aromatic dicarboxylic acid is 15 mass% or more relative to the polybasic acid.

[0015] The present invention [7] includes the printing primer according to any one of the above [1] to [6], in which the chain extender includes an amino group-containing compound.

[0016] The present invention [8] includes a laminate comprising a substrate, a primer layer, and a printing layer in that order, the primer layer being a dried coating of the printing primer described in any one of the above [1] to [7]. Effect of the Invention

[0017] According to the printing primer of the present invention, the active hydrogen group-containing compound containing a polyoxyethylene group is nonionic, and therefore has excellent stability against cationicity.

[0018] In addition, this printing primer has excellent adhesion because the content of polyoxyethylene groups relative to the polyurethane resin is a specified ratio.

[0019] According to the laminate of the present invention, the primer layer is formed from the printing primer of the present invention, and therefore has excellent adhesion to the substrate. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram showing one embodiment of a method for producing a laminate of the present invention, in which FIG. 1A shows a step of preparing a substrate, FIG. 1B shows a step of arranging a primer layer on one side of the substrate, and FIG. 1C shows a step of arranging a printing layer on one side of the primer layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The printing primer of the present invention comprises a polyurethane dispersion containing a polyurethane resin which is a reaction product of an isocyanate-terminated prepolymer, which is a reaction product of a polyisocyanate component and a polyol component containing a macropolyol and an active hydrogen group-containing compound containing a polyoxyethylene group, and a chain extender, and preferably consists of the polyurethane dispersion.

[0022] Examples of the polyisocyanate component include polyisocyanates such as aromatic polyisocyanates, araliphatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates.

[0023] Examples of aromatic polyisocyanates include aromatic diisocyanates such as 4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate or a mixture thereof (MDI), 2,4- or 2,6-tolylene diisocyanate or a mixture thereof (TDI), o-tolidine diisocyanate, 1,5-naphthalene diisocyanate (NDI), m- or p-phenylene diisocyanate or a mixture thereof, 4,4'-diphenyl diisocyanate, and 4,4'-diphenyl ether diisocyanate.

[0024] Examples of the aromatic aliphatic polyisocyanate include aromatic aliphatic diisocyanates such as 1,3- or 1,4-bis(isocyanatomethyl)benzene (also known as 1,3- or 1,4-xylylene diisocyanate) or a mixture thereof (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI), and ω,ω′-diisocyanato-1,4-diethylbenzene.

[0025] Examples of alicyclic polyisocyanates include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'-, 2,4'- or 2,2'-methylenebis(cyclohexyl isocyanate) or mixtures thereof (H 12Examples of the isocyanate include alicyclic diisocyanates such as 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof (H6XDI), bis(isocyanatomethyl)norbornane (NBDI), 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, and methyl-2,6-cyclohexane diisocyanate. Of these, preferred are 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, and more preferred are 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate.

[0026] Examples of the aliphatic polyisocyanate include aliphatic diisocyanates such as hexamethylene diisocyanate (hexane diisocyanate) (HDI), pentamethylene diisocyanate (pentane diisocyanate) (PDI), tetramethylene diisocyanate, trimethylene diisocyanate, 1,2-, 2,3- or 1,3-butylene diisocyanate, and 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, and preferably hexamethylene diisocyanate.

[0027] Examples of the polyisocyanate include polyisocyanate derivatives, such as multimers of the above-mentioned polyisocyanates (e.g., dimers, trimers (e.g., isocyanurate-modified products, iminooxadiazinedione-modified products), pentamers, heptamers, etc.), allophanate-modified products (e.g., allophanate-modified products produced by the reaction of the above-mentioned polyisocyanates with monohydric alcohols or dihydric alcohols), polyol-modified products (e.g., polyol-modified products (alcohol addition products) produced by the reaction of the above-mentioned polyisocyanates with trihydric alcohols (e.g., trimethylolpropane, etc.)), and modified polyisocyanates), biuret modified products (for example, the biuret modified products produced by the reaction of the above-mentioned polyisocyanates with water or amines), urea modified products (for example, the urea modified products produced by the reaction of the above-mentioned polyisocyanates with diamines), oxadiazinetrione modified products (for example, the oxadiazinetrione modified products produced by the reaction of the above-mentioned polyisocyanates with carbon dioxide), carbodiimide modified products (for example, the carbodiimide modified products produced by the above-mentioned decarboxylation condensation reaction of the polyisocyanates), uretdione modified products, and uretonimine modified products.

[0028] The polyisocyanate component preferably includes an alicyclic polyisocyanate and an aliphatic polyisocyanate. That is, the polyisocyanate component preferably includes an alicyclic polyisocyanate and / or an aliphatic polyisocyanate.

[0029] When the polyisocyanate component contains an alicyclic polyisocyanate and / or an aliphatic polyisocyanate, the adhesion to the substrate can be improved.

[0030] More preferably, the polyisocyanate component includes an alicyclic polyisocyanate. That is, more preferably, the polyisocyanate component includes an alicyclic polyisocyanate.

[0031] The polyisocyanate component can be used alone or in combination of two or more kinds.

[0032] The polyol component contains, as essential components, a macropolyol and an active hydrogen group-containing compound that contains a polyoxyethylene group.

[0033] The macropolyol is a compound having two or more hydroxyl groups at the molecular terminals and having a number average molecular weight of 400 or more, preferably 500 or more, and 10,000 or less, preferably 5,000 or less, more preferably 3,000 or less.

[0034] The average functionality of the macropolyol is, for example, 2 or more, and, for example, 3 or less, and preferably 2.

[0035] Examples of macropolyols include polyester polyols, polyether polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, polyolefin polyols, acrylic polyols, silicone polyols, fluorine polyols, and vinyl monomer-modified polyols, and preferably include polyester polyols, polyether polyols, and polycarbonate polyols.

[0036] The polyester polyol may be, for example, a polycondensate of a low molecular weight polyol and a polybasic acid, which will be described later.

[0037] The low molecular weight polyol is preferably a dihydric alcohol, more preferably an aliphatic diol, further preferably an alkanediol, particularly preferably ethylene glycol, 1,6-hexanediol, or neopentyl glycol, and most preferably ethylene glycol or neopentyl glycol.

[0038] Examples of polybasic acids include aromatic dibasic acids, alicyclic dibasic acids, and aliphatic dibasic acids.

[0039] Examples of aromatic dibasic acids include aromatic dicarboxylic acids such as phthalic acid (orthophthalic acid, isophthalic acid, terephthalic acid) and trimellitic acid, and preferably phthalic acid, and more preferably isophthalic acid.

[0040] Examples of the alicyclic dibasic acid include alicyclic carboxylic acids such as HET acid and 1,2-hexahydrophthalic acid.

[0041] Examples of aliphatic dibasic acids include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, hexylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylsuccinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. Preferred are aliphatic dicarboxylic acids having 6 to 12 carbon atoms, and more preferred are adipic acid and sebacic acid.

[0042] The polybasic acid is preferably an aromatic dibasic acid or an aliphatic dibasic acid, more preferably an aromatic dibasic acid, and further preferably an aromatic dicarboxylic acid.

[0043] That is, more preferably, the polybasic acid includes an aromatic dicarboxylic acid.

[0044] When the polybasic acid contains an aromatic dicarboxylic acid, the blending ratio of the aromatic dicarboxylic acid relative to the polybasic acid is, for example, 10 mass% or more, preferably 15 mass% or more, more preferably 20 mass% or more, even more preferably 30 mass% or more, particularly preferably 50 mass% or more, and for example, 70 mass% or less.

[0045] When the blending ratio of the aromatic dicarboxylic acid is equal to or more than the above lower limit, the adhesion to the substrate can be improved.

[0046] As the polybasic acid, preferably, an aromatic dibasic acid and an aliphatic dibasic acid are used in combination, and more preferably, an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid are used in combination.

[0047] To obtain the polyester polyol, a polybasic acid and a low molecular weight polyol are reacted (polycondensation reaction).

[0048] As reaction conditions, the reaction temperature is, for example, 180° C. or higher and, for example, 250° C. or lower, and the reaction time is, for example, 1 hour or higher, preferably 12 hours or higher, more preferably 16 hours or higher, and, for example, 30 hours or lower.

[0049] In the above reaction, a catalyst such as tin octoate can be added in an appropriate ratio.

[0050] This gives a polyester polyol.

[0051] Examples of polyester polyols include polycaprolactone polyols and polyvalerolactone polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone using a low-molecular-weight polyol (preferably a dihydric alcohol) described later as an initiator, and lactone-based polyester polyols obtained by copolymerizing these with a dihydric alcohol described later.

[0052] Examples of such polyester polyols include, preferably, a polycondensation product of an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and a dihydric alcohol, or a polycondensation product of an aliphatic dicarboxylic acid and a dihydric alcohol; more preferably, a polycondensation product of an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and an aliphatic diol, or a polycondensation product of an aliphatic dicarboxylic acid and an aliphatic diol; even more preferably, a polycondensation product of an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and an alkanediol, or a polycondensation product of an aliphatic dicarboxylic acid and an alkanediol; particularly preferably, a polycondensation product of sebacic acid, isophthalic acid, ethylene glycol, and neopentyl glycol, a polycondensation product of sebacic acid, ethylene glycol, and neopentyl glycol, or a polycondensation product of adipic acid, neopentyl glycol, and 1,6-hexanediol; and most preferably, a polycondensation product of sebacic acid, isophthalic acid, ethylene glycol, and neopentyl glycol.

[0053] Examples of polyether polyols include polyoxyalkylene (carbon number 2 to 3) polyols and polytetramethylene ether polyols.

[0054] Examples of polyoxyalkylene (C2-3) polyols include low molecular weight polyols described below and addition polymers of alkylene oxides having C2-3 using known low molecular weight polyamines as initiators.

[0055] Examples of alkylene oxides having 2 to 3 carbon atoms include propylene oxide, ethylene oxide, etc. These alkylene oxides can be used alone or in combination of two or more kinds.

[0056] Specific examples of polyoxyalkylene (carbon number 2 to 3) polyols include polyoxyethylene glycol, polyoxypropylene glycol, and random and / or block copolymers of propylene oxide and ethylene oxide.

[0057] Moreover, the polyoxyalkylene (carbon number 2 to 3) polyol further includes polytrimethylene ether glycol and the like.

[0058] An example of polytrimethylene ether glycol is glycol obtained by polycondensation reaction of 1,3-propanediol derived from plant components.

[0059] Examples of polytetramethylene ether polyols include ring-opening polymers (polytetramethylene ether glycol (crystalline)) obtained by cationic polymerization of tetrahydrofuran, and amorphous (non-crystalline) polytetramethylene ether glycols in which polymerization units of tetrahydrofuran, etc. are copolymerized with alkyl-substituted tetrahydrofuran or the above-mentioned dihydric alcohols.

[0060] The polyether polyol is preferably polytetramethylene ether polyol, and more preferably polytetramethylene ether glycol.

[0061] Examples of the polycarbonate polyol include a ring-opening polymer of ethylene carbonate using a low-molecular-weight polyol (preferably a dihydric alcohol) described later as an initiator, and a polycarbonate diol such as an amorphous polycarbonate polyol obtained by copolymerizing a ring-opening polymer with a dihydric alcohol such as 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, or 1,6-hexanediol.

[0062] More preferably, the macropolyol is a polyester polyol.

[0063] The macropolyols can be used alone or in combination of two or more kinds.

[0064] The mixing ratio of the macropolyol relative to 100 parts by mass of the total amount of the polyol components is, for example, 50 parts by mass or more, preferably 65 parts by mass or more, and for example, 90 parts by mass or less, preferably 80 parts by mass or less.

[0065] Examples of the active hydrogen group-containing compound containing a polyoxyethylene group include one-end-blocked polyoxyethylene glycol and polyols containing a polyoxyethylene side chain.

[0066] The one-end-blocked polyoxyethylene glycol has a polyoxyethylene group introduced at the end of the main chain.

[0067] Examples of the polyoxyethylene glycol having one end blocked include alkoxyethylene glycol having one end blocked with an alkyl group (monoalkoxypolyethylene glycol).

[0068] In the monoalkoxypolyethylene glycol, the number of carbon atoms in the alkyl group for capping one end is, for example, 1 or more, and for example, 20 or less, preferably 10 or less, more preferably 8 or less, even more preferably 4 or less, and particularly preferably 2 or less. That is, preferred examples of the alkyl group for capping one end include a methyl group and an ethyl group.

[0069] Specific examples of such monoalkoxypolyethylene glycols having one end blocked with an alkyl group include methoxypolyethylene glycol and ethoxypolyethylene glycol, and preferably methoxypolyethylene glycol.

[0070] The polyol containing a polyoxyethylene side chain is a compound which contains a polyoxyethylene group in the side chain and has two or more (preferably two) hydroxyl groups at the terminals of the main chain.

[0071] Also, polyols containing polyoxyethylene side chains can be synthesized as follows.

[0072] That is, first, a diisocyanate and a one-end-blocked polyoxyethylene glycol are subjected to a urethane reaction in such a ratio that the isocyanate groups of the diisocyanate are in excess relative to the hydroxyl groups of the one-end-blocked polyoxyethylene glycol, and if necessary, unreacted diisocyanate is removed to obtain a polyoxyethylene chain-containing monoisocyanate.

[0073] As the diisocyanate, preferably, the above-mentioned aliphatic diisocyanates and the above-mentioned alicyclic diisocyanates are used.

[0074] Examples of the one-end-capped polyoxyethylene glycol include the above-mentioned one-end-capped polyoxyethylene glycol, preferably an alkoxyethylene glycol one-end-capped with an alkyl group having 1 to 4 carbon atoms, more preferably an alkoxyethylene glycol one-end-capped with an alkyl group having 1 to 2 carbon atoms.

[0075] The reaction conditions may be known conditions and are appropriately set depending on the purpose and application.

[0076] Next, the obtained polyoxyethylene chain-containing monoisocyanate and dialkanolamine (for example, diethanolamine, etc.) are subjected to a urea-forming reaction in such a ratio that the amount of the isocyanate group of the polyoxyethylene group-containing monoisocyanate is approximately equal to the amount of the secondary amino group of the dialkanolamine.

[0077] This gives a polyol containing a polyoxyethylene side chain (preferably a diol containing a polyoxyethylene side chain).

[0078] As the active hydrogen group-containing compound containing a polyoxyethylene group, preferably, a polyol containing a polyoxyethylene side chain is used.

[0079] The degree of polymerization of the polyoxyethylene unit in the active hydrogen group-containing compound containing a polyoxyethylene group is, for example, 5 or more, preferably 10 or more, more preferably 15 or more, and for example, 30 or less.

[0080] When the degree of polymerization is equal to or more than the lower limit, the adhesion to the substrate can be improved.

[0081] The number average molecular weight of the active hydrogen group-containing compound that contains a polyoxyethylene group is, for example, 300 or more and, for example, 1,500 or less.

[0082] The mixing ratio of the active hydrogen group-containing compound containing a polyoxyethylene group is, for example, 20 parts by mass or more, and for example, 50 parts by mass or less, preferably 40 parts by mass or less, and more preferably 30 parts by mass or less, relative to 100 parts by mass of the total amount of the polyol component.

[0083] The active hydrogen group-containing compound containing a polyoxyethylene group can be used alone or in combination of two or more kinds.

[0084] Such an active hydrogen group-containing compound containing a polyoxyethylene group has nonionic properties and is therefore excellent in stability against cationic properties.

[0085] Furthermore, when the polyol component contains an active hydrogen group-containing compound that contains a polyoxyethylene group, the water contact angle (described later) can be reduced.

[0086] The polyol component also optionally contains a low molecular weight polyol (a low molecular weight polyol excluding polyols containing polyoxyethylene side chains).

[0087] The low molecular weight polyol is a compound having two or more hydroxyl groups and a number average molecular weight of 40 or more but less than 400, preferably 300 or less, and examples thereof include dihydric alcohols and trihydric or higher alcohols.

[0088] Examples of dihydric alcohols include alkanediols such as ethylene glycol, propylene glycol (1,2- or 1,3-propanediol or a mixture thereof), butylene glycol (1,2-, 1,3-, or 1,4-butylene glycol or a mixture thereof), 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, and 3,3-dimethylolheptane; and aliphatic diols such as ether diols such as diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of the diol include cyclohexanediol (1,2- or 1,3- or 1,4-cyclohexanediol or a mixture thereof), cyclohexanedimethanol (1,2- or 1,3- or 1,4-cyclohexanedimethanol or a mixture thereof), cyclohexanediethanol (1,2- or 1,3- or 1,4-cyclohexanediethanol or a mixture thereof), and alicyclic diols such as hydrogenated bisphenol A; and aromatic diols such as bisphenol A, an ethylene oxide adduct of bisphenol A, and a propylene oxide adduct of bisphenol A. Preferably, an aliphatic diol is used, more preferably an ether diol, and even more preferably triethylene glycol is used.

[0089] Examples of trihydric or higher alcohols include trihydric alcohols (low molecular weight triols) such as 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; tetrahydric alcohols such as tetramethylolmethane (pentaerythritol) and diglycerin; pentahydric alcohols such as xylitol; hexahydric alcohols such as sorbitol, mannitol, allitol, iditol, dulcitol, altritol, inositol, and dipentaerythritol; heptahydric alcohols such as perseitol; and octahydric alcohols such as sucrose.

[0090] Examples of the trivalent or higher alcohol include trivalent or higher polyalkylene oxides having a number average molecular weight of 40 or more and less than 400, preferably 300 or less. Such polyalkylene oxides can be obtained as polyethylene polyols, polypropylene polyols, polyethylene polypropylene polyols (random or block copolymers), etc., by addition reaction of alkylene oxides such as ethylene oxide and / or propylene oxide with the above-mentioned low-molecular-weight trivalent or higher polyols or trivalent or higher polyamines as an initiator.

[0091] The trihydric or higher alcohol is preferably a trihydric alcohol, and more preferably trimethylolpropane.

[0092] The low molecular weight polyols can be used alone or in combination of two or more kinds. Preferably, a dihydric alcohol is used alone, or a dihydric alcohol and a trihydric alcohol are used in combination.

[0093] The mixing ratio of the low molecular weight polyol relative to 100 parts by mass of the total amount of the polyol components is, for example, 1 part by mass or more and, for example, 10 parts by mass or less.

[0094] The polyol component preferably includes a macropolyol, an active hydrogen group-containing compound containing a polyoxyethylene group, and a low molecular weight polyol, and more preferably includes a macropolyol, an active hydrogen group-containing compound containing a polyoxyethylene group, and a low molecular weight polyol.

[0095] The polyol component preferably contains a polyol having a branched structure.

[0096] Examples of the polyol having a branched structure include the above-mentioned polyol containing a polyoxyethylene side chain and trihydric or higher alcohols.

[0097] When the polyol component contains a polyol having a branched structure, the isocyanate-terminated prepolymer described below has a branched structure.

[0098] The isocyanate-terminated prepolymer is obtained by reacting a polyisocyanate component with a polyol component.

[0099] In the reaction between the polyisocyanate component and the polyol component, the above components are reacted by a known polymerization method such as bulk polymerization or solution polymerization, preferably by solution polymerization which allows easier adjustment of reactivity and viscosity.

[0100] In this reaction, the equivalent ratio (isocyanate group / active hydrogen group) of the isocyanate group in the polyisocyanate component to the active hydrogen group (hydroxyl group and / or amino group) in the polyol component exceeds 1, for example, 1.2 or more, preferably 1.3 or more, for example, 3.0 or less, preferably 2.5 or less.

[0101] In solution polymerization, for example, the above components are mixed in an organic solvent (solvent) under a nitrogen atmosphere and reacted.

[0102] As for the reaction conditions, the reaction temperature is, for example, 20° C. or higher and, for example, 80° C. or lower, and the reaction time is, for example, 1 hour or higher and, for example, 20 hours or lower.

[0103] Examples of the organic solvent include those which are inactive to isocyanate groups and highly hydrophilic, such as acetone, methyl ethyl ketone, ethyl acetate, tetrahydrofuran, acetonitrile, and N-methylpyrrolidone.

[0104] In the above polymerization, a reaction catalyst such as an amine-based, tin-based, or lead-based catalyst may be added as necessary, and unreacted polyisocyanate can be removed from the resulting isocyanate-terminated prepolymer by a known method such as distillation or extraction.

[0105] This produces an isocyanate-terminated prepolymer, which is a reaction product of the polyisocyanate component and the polyol component.

[0106] When the polyisocyanate component and the polyol component are reacted by solution polymerization, the isocyanate-terminated prepolymer is obtained as an isocyanate-terminated prepolymer reaction liquid containing the isocyanate-terminated prepolymer and an organic solvent.

[0107] The isocyanate-terminated prepolymer obtained in this manner is a polyurethane prepolymer having at least one (preferably multiple, more preferably two) free isocyanate groups at its molecular end, and the isocyanate group content (isocyanate group content calculated as solid content excluding solvent) is, for example, 0.3 mass% or more, preferably 1.0 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less.

[0108] The average functionality of the isocyanate groups is, for example, 1.5 or more and, for example, 3.0 or less, preferably 2.5 or less.

[0109] The isocyanate-terminated prepolymer preferably has a branched structure.

[0110] If the isocyanate-terminated prepolymer has a branched structure, the adhesion to the substrate can be improved.

[0111] In this method, the isocyanate-terminated prepolymer obtained above is then reacted with a chain extender in, for example, water to obtain a polyurethane dispersion containing a polyurethane resin.

[0112] The chain extender is a compound having two or more (preferably two) active hydrogen groups (hydroxyl groups and / or amino groups) and a number average molecular weight of 40 or more and less than 400. Examples of the chain extender include the low molecular weight polyols and amino group-containing compounds described above.

[0113] Examples of the amino group-containing compound include aromatic polyamines, araliphatic polyamines, alicyclic polyamines, aliphatic polyamines, amino alcohols, polyoxyethylene group-containing polyamines, primary amino groups, or alkoxysilyl compounds having primary amino groups and secondary amino groups, hydrazine or derivatives thereof, and other amino group-containing compounds.

[0114] Examples of aromatic polyamines include 4,4'-diphenylmethanediamine and tolylenediamine.

[0115] Araliphatic polyamines include, for example, 1,3- or 1,4-xylylenediamine or mixtures thereof.

[0116] Examples of alicyclic polyamines include 3-aminomethyl-3,5,5-trimethylcyclohexylamine (also known as isophoronediamine), 4,4'-dicyclohexylmethanediamine, 2,5(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- and 1,4-bis(aminomethyl)cyclohexane, and mixtures thereof.

[0117] Examples of the aliphatic polyamine include ethylenediamine, propylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1,2-diaminoethane, 1,2-diaminopropane, and 1,3-diaminopentane, and preferably ethylenediamine.

[0118] Examples of amino alcohols include 2-((2-aminoethyl)amino)ethanol (also known as N-(2-aminoethyl)ethanolamine), 2-((2-aminoethyl)amino)-1-methylpropanol (also known as N-(2-aminoethyl)isopropanolamine), and preferably 2-((2-aminoethyl)amino)ethanol (also known as N-(2-aminoethyl)ethanolamine).

[0119] Examples of polyoxyethylene group-containing polyamines include polyoxyalkylene ether diamines such as polyoxyethylene ether diamine. More specific examples include PEG#1000 diamine manufactured by Nippon Oil & Fats Co., Ltd., and Jeffamine ED-2003, EDR-148, and XTJ-512 manufactured by Huntsman Co., Ltd.

[0120] Examples of alkoxysilyl compounds having a primary amino group or a primary amino group and a secondary amino group include alkoxysilyl compounds having a primary amino group such as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; N-β(aminoethyl)γ-aminopropyltrimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane); N-β(aminoethyl)γ-aminopropyltriethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltriethoxysilane); N-β(aminoethyl)γ-aminopropyltriethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltriethoxysilane); Examples of the alkoxysilyl compounds include those having a primary amino group and a secondary amino group, such as aminopropylmethyldimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane) and N-β(aminoethyl)γ-aminopropylmethyldiethoxysilane (also known as N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane). Of these, preferred are alkoxysilyl compounds having a primary amino group and a secondary amino group, and more preferred are N-β(aminoethyl)γ-aminopropyltrimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane).

[0121] Examples of hydrazine or a derivative thereof include hydrazine (including hydrates), succinic acid dihydrazide, and adipic acid dihydrazide, and preferably hydrazine.

[0122] These amino group-containing compounds can be used alone or in combination of two or more kinds.

[0123] As the chain extender, preferably, an amino group-containing compound is used.

[0124] When the chain extender contains an amino group-containing compound, the adhesion to the substrate can be improved.

[0125] More preferred examples of the chain extender include amino alcohols, aliphatic polyamines, alkoxysilyl compounds having a primary amino group or a primary amino group and a secondary amino group, and hydrazine or its derivatives. Still more preferred are the use of an aliphatic polyamine alone or in combination with an amino alcohol and a primary amino group, or an alkoxysilyl compound having a primary amino group and a secondary amino group.

[0126] To react the above-mentioned isocyanate-terminated prepolymer with a chain extender in water, for example, the isocyanate-terminated prepolymer is first added to water to disperse the isocyanate-terminated prepolymer in water, and then a chain extender is added thereto to extend the chain of the isocyanate-terminated prepolymer by the chain extender.

[0127] To disperse the isocyanate-terminated prepolymer in water, the isocyanate-terminated prepolymer is added to water under stirring in a ratio of 50 to 1000 parts by mass per 100 parts by mass of the isocyanate-terminated prepolymer.

[0128] Thereafter, the chain extender is dropped into the water in which the isocyanate-terminated prepolymer is dispersed under stirring so that the equivalent ratio of the active hydrogen groups (amino groups and hydroxyl groups) of the chain extender to the isocyanate groups of the isocyanate-terminated prepolymer (active hydrogen groups / isocyanate groups) is, for example, 0.6 to 1.2.

[0129] The chain extender may be added dropwise as an aqueous solution, and after the addition is completed, the reaction is completed, for example, at room temperature while continuing to stir. The reaction time until the reaction is completed is, for example, 0.1 hours or more and, for example, 10 hours or less.

[0130] Conversely, water can be added to the isocyanate-terminated prepolymer to disperse the isocyanate-terminated prepolymer in water, and then a chain extender can be added thereto to extend the chains of the isocyanate-terminated prepolymer with the chain extender.

[0131] In this method, the organic solvent and water can be removed as necessary, and further, the solid content concentration can be adjusted by adding water.

[0132] This gives a polyurethane dispersion containing a polyurethane resin which is a reaction product of the isocyanate-terminated prepolymer and the chain extender.

[0133] In addition, various additives can be blended into the polyurethane dispersion as necessary, such as stabilizers (antioxidants, heat stabilizers, ultraviolet absorbers, etc.), plasticizers, antistatic agents, lubricants, antiblocking agents, surfactants, dispersion stabilizers, colorants (pigments, dyes, etc.), fillers, inorganic particles, inorganic oxide particles, crystal nucleating agents, etc.

[0134] The mixing ratio of the additives is not particularly limited and may be appropriately set depending on the purpose and application.

[0135] The solids concentration of the obtained polyurethane dispersion is, for example, 10 mass% or more, preferably 15 mass% or more, more preferably 20 mass% or more, and for example, 60 mass% or less, preferably 50 mass% or less, more preferably 45 mass% or less.

[0136] The pH of the polyurethane dispersion is, for example, 6 or more, preferably 6.5 or more, and for example, 9 or less, preferably 8 or less.

[0137] The viscosity of the polyurethane dispersion at 25° C. is, for example, 10 mPa·s or more, preferably 15 mPa·s or more, and for example, 100 mPa·s or less, preferably 50 mPa·s or less, more preferably 40 mPa·s or less.

[0138] The average particle size of the polyurethane dispersion is, for example, 10 nm or more, preferably 30 nm or more, preferably 100 nm or more, and for example, 300 nm or less, preferably 250 nm or less, more preferably 180 nm or less.

[0139] In addition, in the polyurethane dispersion, the content of polyoxyethylene groups relative to the polyurethane resin is 5 mass% or more, preferably 10 mass% or more, and 30 mass% or less, preferably 25 mass% or less, more preferably 20 mass% or less, and even more preferably 18 mass% or less.

[0140] When the content is equal to or more than the lower limit, the adhesion to the substrate can be improved, and the water contact angle (described later) can be reduced.

[0141] On the other hand, if the content is less than the lower limit, the adhesion to the substrate decreases and the water contact angle (described later) increases.

[0142] When the content is equal to or less than the upper limit, the adhesion to the substrate can be improved, and the filtration rate (described later) can be improved.

[0143] On the other hand, if the content exceeds the upper limit, or is less than the lower limit, the adhesion to the substrate decreases, and the filtration rate (described later) decreases.

[0144] In the polyurethane dispersion, the active hydrogen group-containing compound containing a polyoxyethylene group has nonionic properties, and therefore has excellent stability against cationic properties.

[0145] Such a polyurethane dispersion is used as a printing primer when a printing layer is disposed on a substrate.

[0146] Such a printing primer has a specified content of the polyoxyethylene group and uses an active hydrogen group-containing compound that contains a polyoxyethylene group, and therefore has an excellent filtration rate (described later) and a low water contact angle (described later).

[0147] Therefore, the printing primer can be suitably used as a primer for inkjet printing.

[0148] Hereinafter, a method for producing a laminate 4 by forming a primer layer 2 on a substrate 1 using a printing primer and then forming a printing layer 3 on the primer layer 2 will be described in detail.

[0149] In this method, first, a substrate 1 is prepared as shown in FIG. 1A.

[0150] The substrate 1 is not particularly limited, and examples thereof include plastic films made of plastic materials such as cellulose, polyethylene, ethylene-vinyl acetate copolymer, ionomer, polypropylene, polyamide (nylon), polyester, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polycarbonate, polystyrene, and polyacrylonitrile copolymer.

[0151] The thickness of the substrate 1 is, for example, 10 μm or more and, for example, 100 μm or less, preferably 50 μm or less.

[0152] 1B, a printing primer is applied to the entire surface of one side of the substrate 1 and dried to form a primer layer 2. That is, the primer layer 2 is a dried coating of the printing primer.

[0153] Specifically, the mass per unit area of ​​the primer layer 2 is, for example, 0.1 g / m 2 or more, for example, 1.0 g / m 2 Apply as follows:

[0154] Examples of the coating method include known coating methods such as a bar coater method, a curtain coating method, a roll coating method, and a blade coating method.

[0155] As for the drying conditions, the drying time is, for example, 30 seconds or more, and preferably 360 seconds or less, and preferably 120 seconds or less, and the drying temperature is, for example, 60°C or more, and, for example, 100°C or less.

[0156] As a result, a primer layer 2 is formed on one surface of the substrate 1.

[0157] Next, as shown in FIG. 1C, a printed layer 3 is formed on the entire surface of one side of the primer layer 2.

[0158] The print layer 3 is formed from an ink composition.

[0159] The ink composition contains a binder resin, a pigment, and a solvent.

[0160] Examples of the binder resin include acrylic resin and urethane resin, and preferably, urethane resin.

[0161] The urethane resin may be, for example, a water-based polyurethane dispersion. As the water-based polyurethane dispersion, a commercially available product may be used, specifically, Takelac W6110 (manufactured by Mitsui Chemicals, Inc.) or the like.

[0162] The pigment is not particularly limited and is appropriately selected depending on the purpose and application.

[0163] The blending ratio of the pigment is, for example, 1 part by mass or more and, for example, 10 parts by mass or less with respect to 100 parts by mass of the binder resin.

[0164] Examples of the solvent include alkane diols such as ethylene glycol, propylene glycol, and butylene glycol; and ether diols such as diethylene glycol, triethylene glycol, and dipropylene glycol. Preferably, propylene glycol or diethylene glycol is used, and more preferably, propylene glycol and diethylene glycol are used in combination.

[0165] The ink composition further contains a surfactant, if necessary.

[0166] The surfactant may be, for example, a silicone surfactant.

[0167] The ink composition can also be diluted with water.

[0168] When the ink composition is diluted with water, the solid content concentration is, for example, 10% by mass or more and, for example, 30% by mass or less.

[0169] To form a printed layer 3 on the entire surface of one side of the primer layer 2 (or to form a printed layer 3 having a predetermined pattern shape on part of one side of the primer layer 2), an ink composition is applied to the entire surface or part of one side of the primer layer 2 and dried, and then cured.

[0170] Examples of the method for applying the ink composition include printing methods such as flexographic printing, offset printing, gravure printing, screen printing, and inkjet printing, and preferably inkjet printing.

[0171] FIG. 1C illustrates a case in which a printed layer 3 is formed on the entire surface of one side of the primer layer 2.

[0172] Specifically, the mass per unit area of ​​the printing layer 3 is, for example, 1.0 g / m 2 or more, for example, 3.0 g / m 2 Apply as follows:

[0173] The application method is the same as the application method for the printing primer described above.

[0174] The drying conditions are the same as those for the printing primer described above.

[0175] As for the curing conditions, the curing temperature is, for example, 20° C. or more and, for example, 50° C. or less, and the curing time is, for example, 0.5 day or more and, for example, 4 days or less.

[0176] As a result, a laminate 4 having the substrate 1, the primer layer 2, and the printed layer 3 in this order is obtained.

[0177] In the laminate 4, the primer layer 2 is formed from the printing primer of the present invention, and therefore has excellent adhesion to the substrate 1.

[0178] Furthermore, since the primer layer 2 is formed from a printing primer, it has excellent stability against cationic properties.

[0179] Therefore, the primer layer 2 has excellent stability against the printed layer 3 containing the ink composition (cationic). EXAMPLES

[0180] Specific numerical values ​​of the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numerical values ​​defined as "not more than" or "less than") or lower limit values ​​(numerical values ​​defined as "not less than" or "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Form for carrying out the invention." In addition, unless otherwise specified in the following description, "parts" and "%" are based on mass. 1.Details of ingredients IPDI: 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate H6XDI: 1,3-bis(isocyanatomethyl)cyclohexane HDI: Hexamethylene diisocyanate TDI: Tolylene diisocyanate Plaxel 220: Polycaprolactone diol, number average molecular weight 2000, manufactured by Daicel PTG2000SN: Polytetramethylene ether glycol, number average molecular weight 2000, manufactured by Hodogaya Chemical UH-200: Polycarbonate diol, number average molecular weight 2000, manufactured by Ube Industries, Ltd. TEG: Triethylene glycol TMP: Trimethylolpropane DHD1000S: Polyoxyethylene chain-containing diol, number average molecular weight 1273 DHD550: Polyoxyethylene chain-containing diol, number average molecular weight 823 DHD400: Polyoxyethylene chain-containing diol, number average molecular weight 673 MePEG1000: Methoxypolyethylene glycol, number average molecular weight 1000 DMPA: Dimethylolpropionic acid TEA: Triethylamine AN: Acetonitrile KBM-603: Alkoxysilyl compound, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd. A-EA: 2-((2-aminoethyl)amino)ethanol EDA: Ethylenediamine HYD: Hydrazine dihydrate 2. Preparation of Polyester Polyol Preparation Example 1 In a reaction vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, a polybasic acid, a low molecular weight polyol, and a catalyst (tin stannoct(octylate)) were charged according to the descriptions in Table 1 while introducing nitrogen gas, and a polyester polyol was obtained by carrying out a polycondensation reaction at 210°C for 20 hours until the acid value reached 1 or less.

[0181] Preparation Examples 2 to 5 A polyester polyol was obtained in the same manner as in Preparation Example 1, except that the compounding ratio of each component was changed based on the description in Table 1. 3. Preparation of Polyurethane Dispersion Example 1 Based on the description in Table 2, the polyisocyanate component and the polyol component were mixed and reacted under a nitrogen atmosphere at 90 to 95°C until a predetermined NCO% (1 to 6% or less) was reached, to obtain a reaction liquid containing an isocyanate-terminated prepolymer. In this reaction, the equivalent ratio of the isocyanate groups in the polyisocyanate component to the hydroxyl groups in the polyol component (isocyanate groups / hydroxyl groups) was 1.48.

[0182] The reaction solution was then diluted with acetonitrile and dispersed using a homodisper while adding ion-exchanged water. After dispersion, a chain extender diluted with ion-exchanged water was added. In this reaction, the equivalent ratio of the active hydrogen group of the chain extender to the isocyanate group of the isocyanate-terminated prepolymer (active hydrogen group / isocyanate group) was 0.8.

[0183] Thereafter, the reaction was carried out for 1 hour, and then acetonitrile and ion-exchanged water were distilled off using an evaporator. The solid content was adjusted to 35% by mass with ion-exchanged water, thereby obtaining a polyurethane dispersion.

[0184] Example 2 to Example 10. Example 12 to Example 32. Comparative Example 1 to Comparative Example 5 Polyurethane dispersions were obtained in the same manner as in Example 1, except that the compounding recipes of the components were changed based on the descriptions in Tables 2 to 9.

[0185] In Comparative Examples 3 and 4, after obtaining a reaction liquid containing an isocyanate-terminated prepolymer, the reaction liquid was cooled to 40° C. and then neutralized with triethylamine (TEA). 4. Manufacturing of laminates The polyurethane dispersion of each of the Examples and Comparative Examples was diluted with water to a solid content concentration of 5 mass %.

[0186] Next, the polyurethane dispersion was applied to one side of a polypropylene film (OPP, Pyren Film-OT P2161 20 μm, manufactured by Toyobo Co., Ltd.) using a bar coder and dried at 80° C. for 1 minute. This resulted in a primer layer (mass per unit area: 0.3 g / m 2 ) was formed.

[0187] Next, 0.5 parts by mass of white pigment (GP White #101 Concentrate, manufactured by Mikuni Color Co., Ltd.), 10 parts by mass of Takelac W6110, 3.2 parts by mass of propylene glycol, 3.2 parts by mass of diethylene glycol, 33.7 parts by mass of water, and 0.2 parts by mass of BYK-348 (a silicone-based surfactant, manufactured by BYK-Chemie Japan Co., Ltd.) were mixed to prepare an ink composition.

[0188] Next, this ink composition was applied using a bar coder and dried at 80°C for 1 minute. Then, it was aged at 40°C for 1 day. As a result, a printed layer (mass per unit area: 1.5 g / m 2 ) was formed.

[0189] As a result, a laminate was obtained. 5. Evaluation (Adhesion) A mixture of Takenate A-310 (manufactured by Mitsui Chemicals), Takenate A-3 (manufactured by Mitsui Chemicals) and ethyl acetate (Takenate A-310 / Takenate A-3 / ethyl acetate = 5 / 0.5 / 13.7 (mass ratio)) was applied as a dry lamination adhesive to the printed layer of each laminate, with a mass of 1.0 g / m after drying. 2 The coating was applied using a bar coater so that the coating became smooth, and then dried using a dryer.

[0190] Thereafter, a polypropylene film (OPP, Pyren Film-CT P1128 20 μm, manufactured by Toyobo Co., Ltd.) was laminated and cured at 40° C. for 3 days, after which the lamination strength between the substrate and the primer layer of each laminate was measured by a T-peel test (15 mm width) in accordance with JIS K 6854. The results are shown in Tables 2 to 9.

[0191] In addition, Table 2 shows Examples 1 to 7 and Comparative Examples 1 and 2, and compares the content of polyoxyethylene groups relative to the polyurethane resin.

[0192] Table 3 shows Example 1, Comparative Example 3 and Comparative Example 4, and compares the types of active hydrogen group-containing compounds that contain polyoxyethylene groups.

[0193] Table 4 also shows Examples 1, 8 and 9, and compares the degree of polymerization of polyoxyethylene units in active hydrogen group-containing compounds that contain polyoxyethylene groups.

[0194] In addition, Table 5 shows Example 1, Example 10, and comparison example 5 The figures show the presence or absence of a branched structure in the polyol component.

[0195] Moreover, Table 6 shows Examples 12 to 15, and compares the types of macropolyols.

[0196] Moreover, Table 7 shows Example 1, Example 2, Example 16, Example 17, Example 20, and Examples 25 to 32, and compares the types of chain extenders.

[0197] Furthermore, Table 8 shows Examples 1, 18 and 19, and compares the types of isocyanate components.

[0198] Moreover, Table 9 shows Examples 1, 12 and 20 to 24, and compares the blending ratio of aromatic dicarboxylic acid to polybasic acid.

[0199] (water contact angle) The polyurethane dispersion of each Example and Comparative Example was applied to a polypropylene film (2.0 mm×70 mm×150 mm) with a bar coater to a dry thickness of 1.5 μm, and dried at 110° C. for 2 minutes, and then aged at 40° C. for 2 days.

[0200] Then, the water contact angle was measured using an automatic contact angle meter CA-VP manufactured by Kyowa Interface Science Co., Ltd. The results are shown in Tables 2 to 9.

[0201] (Stability against cationic substances) Polyallylamine (manufactured by Nittobo Medical Co., Ltd.) was added at 1% to the polyurethane dispersion of each Example and Comparative Example, and the dispersion was stored at 60° C. for 1 week, after which the appearance was observed.

[0202] The cationic stability was evaluated according to the following criteria, and the results are shown in Tables 2 to 9. ◯: No aggregates or precipitates were observed. ×: Aggregates or precipitates were observed.

[0203] (filtration rate) 20 cc of the polyurethane dispersion of each Example and Comparative Example was placed in a 20 cc syringe, and then filtered using a 0.45 μm syringe filter attached to the syringe.

[0204] The filtration rate was calculated based on the following formula (1). The results are shown in Tables 2 to 9.

[0205] Filtration rate (%) = (20 - (amount of polyurethane dispersion remaining in the syringe after filtration)) / 20 x 100 (1)

[0206] [Table 1]

[0207] [Table 2]

[0208] [Table 3]

[0209] [Table 4]

[0210] [Table 5]

[0211] [Table 6]

[0212] [Table 7]

[0213] [Table 8]

[0214] [Table 9] [Explanation of symbols]

[0215] 4. Laminate

Claims

1. The polyurethane dispersion includes a polyurethane resin which is a reaction product of an isocyanate-terminated prepolymer, which is a reaction product of a polyisocyanate component and a polyol component which includes a macropolyol and an active hydrogen group-containing compound containing a polyoxyethylene group, and a chain extender; The content of polyoxyethylene groups in the polyurethane resin is 5% by mass or more and 30% by mass or less, The isocyanate group-terminated prepolymer has a branched structure, A printing primer, characterized in that the macropolyol comprises a polyester polyol or a polyether polyol.

2. The printing primer according to claim 1 , wherein the polyisocyanate component comprises an aliphatic polyisocyanate and / or an alicyclic polyisocyanate.

3. A polyurethane dispersion comprising a polyurethane resin which is a reaction product of an isocyanate-terminated prepolymer, which is a reaction product of a polyisocyanate component and a polyol component which includes a macropolyol and an active hydrogen group-containing compound containing a polyoxyethylene group, and a chain extender; The content of polyoxyethylene groups in the polyurethane resin is 5% by mass or more and 30% by mass or less, The isocyanate group-terminated prepolymer has a branched structure, A printing primer, characterized in that the polyisocyanate component contains 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate or hexamethylene diisocyanate.

4. The printing primer according to any one of claims 1 to 3, characterized in that the degree of polymerization of the polyoxyethylene unit in the active hydrogen group-containing compound containing the polyoxyethylene group is 10 or more.

5. The printing primer according to any one of claims 1 to 4, characterized in that the macropolyol is a polyester polyol.

6. The polyester polyol is a polymerization product of a polybasic acid and a polyhydric alcohol, the polybasic acid comprises an aromatic dicarboxylic acid; The printing primer according to claim 5 , wherein the blending ratio of the aromatic dicarboxylic acid is 15% by mass or more based on the polybasic acid.

7. The printing primer according to any one of claims 1 to 6, characterized in that the chain extender comprises an amino group-containing compound.

8. A substrate, a primer layer, and a printing layer are provided in this order, A laminate, characterized in that the primer layer is a dried coating of the printing primer according to any one of claims 1 to 7.

Images