Resin composition for water-based ink

Abstract

This resin composition for an aqueous ink contains a base resin, an aqueous dispersion medium, and an emulsifier, the base resin containing a rosin-modified alkyd resin, the emulsifier containing an anionic emulsifier and a nonionic emulsifier, the anionic emulsifier containing an oxyalkylene-containing anionic emulsifier, and the HLB value of the nonionic emulsifier being 16.0-20.0 inclusive.

Description

[Technical field]

[0001] The present invention relates to a resin composition for a water-based ink, and more particularly to a resin composition for a water-based ink containing a base resin. [Background technology]

[0002] Conventionally, resin compositions for water-based inks used for packaging materials and the like contain petroleum-based resins such as acrylic resins.

[0003] In recent years, from the viewpoint of preventing environmental destruction, studies have been conducted on the substitution of all or part of the raw materials for petroleum-based resins with raw materials derived from biomass, thereby achieving carbon neutrality.

[0004] As a carbon-neutral resin, for example, a polyester resin containing a fatty acid and rosin and / or its derivative has been proposed, and an aqueous dispersion containing such a polyester resin and an anionic surfactant and / or a nonionic surfactant has also been proposed (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2013 / 0197152 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the above-mentioned aqueous dispersions are used in inks, the storage stability of the inks may not be sufficient, and the water resistance of the ink coatings may be insufficient.

[0007] The present invention provides a resin composition for water-based inks that can contribute to carbon neutrality and further provide excellent storage stability and water resistance. [Means for solving the problem]

[0008] The present invention [1] comprises a resin composition for an aqueous ink, the resin composition comprising a base resin, an aqueous dispersion medium, and an emulsifier, the base resin comprising a rosin-modified alkyd resin, the emulsifier comprising an anionic emulsifier and a nonionic emulsifier, the anionic emulsifier comprising an oxyalkylene-containing anionic emulsifier, and the nonionic emulsifier having an HLB value of 16.0 or more and 20.0 or less.

[0009] The present invention [2] includes the resin composition for water-based ink described in [1] above, characterized in that the number of oxyalkylene units contained in one molecule of the oxyalkylene-containing anionic emulsifier is 5 or more.

[0010] The present invention [3] includes a resin composition for water-based inks according to the above [1] or [2], in which the number of oxyalkylene units contained in one molecule of the oxyalkylene-containing anionic emulsifier is 10 or more and 18 or less.

[0011] The present invention [4] comprises a resin composition for water-based ink according to any one of the above [1] to [3], wherein the nonionic emulsifier contains an oxyalkylene-containing nonionic emulsifier, and the number of oxyalkylene units contained in one molecule of the oxyalkylene-containing nonionic emulsifier is 30 or more.

[0012] The present invention [5] includes the resin composition for a water-based ink according to any one of the above [1] to [4], wherein the nonionic emulsifier contains a block copolymer of ethylene oxide and propylene oxide.

[0013] The present invention [6] comprises the resin composition for a water-based ink according to any one of the above [1] to [5], wherein the rosin-modified alkyd resin is a reaction product of a resin raw material containing rosin, a fatty acid and / or fats and oils, a polybasic acid, and a polyhydric alcohol.

[0014] The present invention [7] includes the resin composition for a water-based ink described in the above [6], wherein the polybasic acid contains an aromatic dicarboxylic acid.

[0015] The present invention [8] includes the resin composition for water-based ink described in [7] above, in which the content of the aromatic dicarboxylic acid is 11 mass% or more and 23 mass% or less relative to the total amount of the resin raw materials. Effect of the Invention

[0016] In the resin composition for use in a water-based ink of the present invention, the base resin contains a rosin-modified alkyd resin. Since the rosin-modified alkyd resin contains a raw material derived from a plant, the resin composition for use in a water-based ink can contribute to being carbon neutral.

[0017] In the water-based ink resin composition of the present invention, the emulsifier contains an anionic emulsifier containing an oxyalkylene group in the molecule, so that particles of the rosin-modified alkyd resin are well formed in the water-based ink resin composition.

[0018] In addition, in the water-based ink resin composition of the present invention, the emulsifier contains a nonionic emulsifier having an HLB value in a predetermined range. Therefore, when used in an ink composition, the stability of the rosin-modified alkyd resin particles can be improved. As a result, the water-based ink resin composition of the present invention has excellent storage stability and excellent film-forming properties, and therefore the coating film has excellent water resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The resin composition for a water-based ink of the present invention contains a base resin, an aqueous dispersion medium, and an emulsifier.

[0020] The base resin contains a rosin-modified alkyd resin as an essential component.

[0021] Rosin-modified alkyd resins are reaction products of resin raw materials (described below) that contain plant-derived compounds, and therefore can contribute to carbon neutrality and can also improve the gloss, film-forming properties, water resistance, and strength of the coating.

[0022] More specifically, the rosin-modified alkyd resin is a reaction product obtained by reacting a resin raw material containing a rosin, a fatty acid and / or a fat and oil, a polybasic acid, and a polyhydric alcohol.

[0023] Rosins are compounds derived from plants, more specifically, compounds derived from pine trees. Rosins are not particularly limited, but include known rosins and / or derivatives thereof.

[0024] Examples of rosin (unmodified rosin) include raw rosins such as gum rosin, tall rosin, and wood rosin, as well as refined products thereof (refined rosins).

[0025] In addition, the type of pine that is the raw material of rosin is not particularly limited, and examples thereof include Merkusian pine, slash pine (swamp pine), Masson pine, etc. In addition, the place of origin of rosin is not particularly limited, and examples thereof include China, Vietnam, Indonesia, Brazil, etc.

[0026] These rosins can be used alone or in combination of two or more kinds.

[0027] Examples of the rosin derivatives include hydrogenated rosin obtained by hydrogenating the above-mentioned rosin, disproportionated rosin obtained by disproportionating the above-mentioned rosin, polymerized rosin obtained by polymerizing the above-mentioned rosin, and unsaturated carboxylic acid-modified rosin obtained by modifying the above-mentioned rosin with an unsaturated carboxylic acid (e.g., maleic acid, maleic anhydride, fumaric acid, methacrylic acid, etc.).

[0028] These rosin derivatives can be used alone or in combination of two or more kinds.

[0029] These rosins can be used alone or in combination of two or more kinds.

[0030] As the rosins, from the viewpoints of storage stability, film-forming properties, and water resistance, preferably, rosin (unmodified rosin) is used, and more preferably, tall rosin is used.

[0031] The content ratio of rosins relative to the total amount of resin raw materials will vary depending on the content ratio of fatty acids and / or fats and oils described below, but from the viewpoint of adjusting the softening point of the rosin-modified alkyd resin and improving the film-forming properties, and improving the water resistance, gloss, and touch (tack resistance) of the coating film, it is, for example, 30 mass% or more, preferably 40 mass% or more, more preferably 44 mass% or more, and even more preferably 53 mass% or more, and from the viewpoint of suppressing embrittlement of the rosin-modified alkyd resin and improving the film-forming properties, and improving the water resistance, gloss, and touch (tack resistance) of the coating film, it is, for example, 80 mass% or less, preferably 70 mass% or less, more preferably 64 mass% or less, and even more preferably 58 mass% or less.

[0032] The fatty acid and / or fat is contained in the resin raw material in order to improve the flexibility and emulsifiability of the rosin-modified alkyd resin.

[0033] Examples of fatty acids include fatty acids having 12 or more carbon atoms (long-chain fatty acids), fatty acids having 8 to 11 carbon atoms (medium-chain fatty acids), and fatty acids having 7 or less carbon atoms (short-chain fatty acids).

[0034] Examples of fatty acids having 12 or more carbon atoms (long-chain fatty acids) include saturated fatty acids having 12 or more carbon atoms and unsaturated fatty acids having 12 or more carbon atoms.

[0035] Examples of saturated fatty acids having 12 or more carbon atoms include lauric acid (12 carbon atoms), myristic acid (14 carbon atoms), palmitic acid (16 carbon atoms), stearic acid (18 carbon atoms), etc. These may be used alone or in combination of two or more kinds.

[0036] Examples of unsaturated fatty acids having 12 or more carbon atoms include α-linolenic acid (having 18 carbon atoms), linoleic acid (having 18 carbon atoms), oleic acid (having 18 carbon atoms), etc. These may be used alone or in combination of two or more kinds.

[0037] Examples of fatty acids having 8 to 11 carbon atoms (medium-chain fatty acids) include caprylic acid (having 8 carbon atoms), capric acid (having 10 carbon atoms), etc. These may be used alone or in combination of two or more kinds.

[0038] Examples of fatty acids having 7 or less carbon atoms (short-chain fatty acids) include acetic acid (having 2 carbon atoms), butyric acid (having 4 carbon atoms), caproic acid (having 6 carbon atoms), etc. These may be used alone or in combination of two or more kinds.

[0039] Further, fatty acids include mixed fatty acids (unrefined fatty acids).

[0040] Examples of mixed fatty acids include mixed fatty acids (unrefined fatty acids) containing long-chain fatty acids, and more specifically, examples of mixed fatty acids derived from animal fats and oils, such as beef tallow fatty acids, lard fatty acids, fish oil fatty acids, and hydrogenated (hardened) fatty acids thereof, and examples of mixed fatty acids derived from vegetable fats and oils, such as tall oil fatty acids, soybean oil fatty acids, linseed oil fatty acids, tung oil fatty acids, coconut oil fatty acids, castor oil fatty acids, and hydrogenated (hardened) fatty acids thereof. These can be used alone or in combination of two or more kinds.

[0041] These fatty acids can be used alone or in combination of two or more kinds.

[0042] The fatty acid preferably contains a fatty acid having 12 or more carbon atoms (long-chain fatty acid).

[0043] As the fatty acid, more preferably, mixed fatty acids containing long-chain fatty acids are used, even more preferably, mixed fatty acids derived from vegetable fats and oils are used, even more preferably, tall oil fatty acids and soybean oil fatty acids are used, and particularly preferably, soybean oil fatty acids are used.

[0044] Fats and oils are esters of three fatty acid molecules and one glycerin molecule.

[0045] In fats and oils, examples of fatty acids that are esterified with glycerin include the above-mentioned fatty acids having 12 or more carbon atoms (long-chain fatty acids), the above-mentioned fatty acids having 8 to 11 carbon atoms (medium-chain fatty acids), the above-mentioned fatty acids having 7 or less carbon atoms (short-chain fatty acids), etc. These can be used alone or in combination of two or more kinds.

[0046] The fatty acid to be esterified with glycerin preferably contains the above-mentioned fatty acid having 12 or more carbon atoms (long-chain fatty acid), and, if necessary, contains the above-mentioned fatty acid having 8 to 11 carbon atoms (medium-chain fatty acid) and the above-mentioned fatty acid having 7 or less carbon atoms (short-chain fatty acid) in an appropriate ratio.

[0047] More specifically, examples of the oils and fats include animal oils and fats such as beef tallow, lard, and fish oil, vegetable oils and fats such as soybean oil, linseed oil, tung oil, coconut oil, castor oil, palm oil, and rapeseed oil, and further include regenerated oils that are recovered and regenerated after use of the oils and fats. These can be used alone or in combination of two or more kinds.

[0048] As the fat or oil, preferably, vegetable fat or oil is used, and more preferably, soybean oil is used.

[0049] The content ratio of fatty acids and / or fats and oils (if used in combination, their total amount) relative to the total amount of resin raw materials is, from the viewpoint of flexibility and emulsifiability, for example, 1 mass% or more, preferably 3 mass% or more, more preferably 5 mass% or more, even more preferably 7 mass% or more, and for example, 40 mass% or less, preferably 30 mass% or less, more preferably 20 mass% or less, even more preferably 15 mass% or less.

[0050] Examples of polybasic acids include dibasic carboxylic acids, tribasic carboxylic acids, and tetrabasic or higher carboxylic acids.

[0051] Examples of the dicarboxylic acid include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids.

[0052] The aromatic dicarboxylic acid is not particularly limited, but examples thereof include isophthalic acid, terephthalic acid, phthalic acid, diphenylmethane-4,4'-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and acid anhydrides thereof. These may be used alone or in combination of two or more kinds.

[0053] Examples of the aliphatic dicarboxylic acid include chain aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, pimelic acid, suberic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, etc. These can be used alone or in combination of two or more kinds.

[0054] Examples of alicyclic dicarboxylic acids include hexahydrophthalic acid, hexahydrophthalic anhydride, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, etc. These can be used alone or in combination of two or more kinds.

[0055] These divalent carboxylic acids can be used alone or in combination of two or more kinds.

[0056] Examples of trivalent carboxylic acids include aromatic tricarboxylic acids such as trimellitic acid and naphthalene tricarboxylic acid, etc. These can be used alone or in combination of two or more kinds.

[0057] Examples of the tetravalent or higher carboxylic acid include aromatic tetracarboxylic acids such as pyromellitic acid, and tetravalent to octavalent carboxylic acids such as alicyclic tetracarboxylic acids such as cyclohexane tetracarboxylic acid and methylcyclohexane tetracarboxylic acid. These can be used alone or in combination of two or more kinds.

[0058] These polybasic acids can be used alone or in combination of two or more kinds.

[0059] As the polybasic acid, from the viewpoint of controlling the reaction rate, preferably, a dibasic carboxylic acid is used, more preferably, an aromatic dicarboxylic acid is used, and further preferably, terephthalic acid is used.

[0060] The content of the aromatic dicarboxylic acid relative to the total amount of the polybasic acid is, for example, 50 mass% or more, preferably 70 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 100 mass%.

[0061] That is, the polybasic acid preferably comprises an aromatic dicarboxylic acid.

[0062] The content ratio of the polybasic acid (preferably aromatic dicarboxylic acid) relative to the total amount of resin raw materials is, from the viewpoints of stability of the rosin-modified alkyd resin, compatibility with the pigment, and water resistance of the coating film, for example, 5 mass% or more, preferably 8 mass% or more, more preferably 11 mass% or more, and even more preferably 16 mass% or more, and from the viewpoint of controlling the reaction rate, it is, for example, 40 mass% or less, preferably 30 mass% or less, more preferably 23 mass% or less, and even more preferably 20 mass% or less.

[0063] Examples of polyhydric alcohols include dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols.

[0064] Examples of the dihydric alcohol include linear alkyl diols having 2 to 10 carbon atoms, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol; branched alkyl diols having 3 to 10 carbon atoms, such as propylene glycol, 1,3-butanediol, 1,2-butanediol, 3-methyl-1,5-pentanediol, and 2,6-dimethyl-1-octene-3,8-diol; and diethylene glycol, triethylene glycol, and Examples of the diols include ether diols such as glycol and dipropylene glycol, for example, 1,4-dihydroxy-2-butene, isosorbide, 1,3- or 1,4-cyclohexanedimethanol and mixtures thereof, 1,4-cyclohexanediol, tricyclodecane dimethylol, bisphenol A, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol S, hydrogenated catechol, hydrogenated resorcinol, hydrogenated hydroquinone, dicyclopentadiene diallyl alcohol copolymer, etc. These can be used alone or in combination of two or more kinds.

[0065] Examples of trihydric alcohols include glycerin, trimethylol alkanes such as trimethylolethane, trimethylolpropane, trimethylolhexane, and trimethyloloctane. These may be used alone or in combination of two or more kinds.

[0066] Examples of the tetrahydric or higher alcohol include tetrahydric to octahydric alcohols such as pentaerythritol, diglycerin, ditrimethylolpropane, sorbitan, sorbitol, dipentaerythritol, inositol, tripentaerythritol, etc. These may be used alone or in combination of two or more kinds.

[0067] From the viewpoint of water resistance of the coating film, the polyhydric alcohol is preferably a trihydric alcohol or a tetrahydric or higher alcohol, more preferably a trihydric alcohol, even more preferably trimethylolpropane, glycerin, or pentaerythritol, and particularly preferably glycerin.

[0068] The content ratio of polyhydric alcohol relative to the total amount of resin raw materials is, for example, 5 mass% or more, preferably 8 mass% or more, more preferably 12 mass% or more, even more preferably 13 mass% or more, and for example, 30 mass% or less, preferably 25 mass% or less, more preferably 20 mass% or less, even more preferably 17 mass% or less.

[0069] Furthermore, the equivalent ratio (hydroxyl groups / carboxy groups) of hydroxyl groups in the resin raw materials (the total amount of hydroxyl groups in polyhydric alcohols and hydroxyl groups derived from glycerin in fats and oils) to carboxy groups in the resin raw materials (the total amount of carboxy groups in rosins, carboxy groups in fatty acids and / or fats and oils, and carboxy groups in polybasic acids) is, from the viewpoint of adjusting the acid value of the rosin-modified alkyd resin, for example, 1.00 or more, preferably 1.10 or more, and more preferably 1.14 or more, and from the viewpoint of the water resistance of the coating film, is, for example, 1.50 or less, preferably 1.40 or less, more preferably 1.36 or less, and particularly preferably 1.14.

[0070] The rosin-modified alkyd resin can be obtained as a reaction product by reacting the above-mentioned resin raw materials by a known method.

[0071] The reaction method is not particularly limited, and the resin raw materials can be reacted in one step or in multiple steps. Preferably, the resin raw materials are reacted in multiple steps.

[0072] More specifically, in this method, first, the components in the resin raw material other than the polybasic acid, i.e., rosins, fatty acids and / or fats and oils, and polyhydric alcohol are charged in the above-mentioned ratio into a reactor, and heated while an inert gas such as nitrogen gas is flowed in. This causes a condensation polymerization reaction (primary reaction) of the rosins, fatty acids and / or fats and oils, and polyhydric alcohol to produce an intermediate product (primary product).

[0073] The reaction conditions in the condensation polymerization reaction are not particularly limited, but the reaction temperature is, for example, 150° C. or more, preferably 170° C. or more, and for example, 300° C. or less, preferably 280° C. or less. The reaction time is, for example, 1 hour or more, preferably 5 hours or more, and for example, 48 hours or less, preferably 24 hours or less.

[0074] In this reaction, if necessary, the water of condensation produced by the polycondensation reaction (primary reaction) is distilled off by a known method.

[0075] In the above reaction, a reaction catalyst can be added in an appropriate ratio as necessary. Examples of reaction catalysts include alkali metal hydroxides, alkaline earth metal oxides and hydroxides, sulfonic acids, tetrabutyl zirconate, monobutyltin oxide, zirconium naphthate, and tetrabutyl titanate. These can be used alone or in combination of two or more.

[0076] The above reaction continues until the acid value of the resulting intermediate product (primary product) reaches a predetermined value.

[0077] That is, the acid value of the intermediate product (primary product) is determined by the ratio of rosins, fatty acids and / or fats and oils, and polyhydric alcohols.

[0078] Therefore, the acid value of the intermediate product (primary product) is calculated from the ratio of these rosins, fatty acids and / or fats and oils, and polyhydric alcohols, and the completion of the above reaction is determined when that acid value is reached.

[0079] The acid value of the intermediate product (primary product) is, for example, 1 mgKOH / g or more, preferably 5 mgKOH / g or more, and for example, 30 mgKOH / g or less, preferably 25 mgKOH / g or less, more preferably 20 mgKOH / g or less.

[0080] The acid value is measured in accordance with JIS K 5601-2-1 (1999) (hereinafter the same).

[0081] Next, in this method, a polybasic acid is added to the intermediate product (primary product) obtained above in the above ratio to cause an esterification reaction (secondary reaction), thereby obtaining a rosin-modified alkyd resin as a reaction product (secondary product) of the resin raw material.

[0082] The reaction conditions in the esterification reaction are not particularly limited, but the reaction temperature is, for example, 150° C. or more, preferably 170° C. or more, and for example, 300° C. or less, preferably 280° C. or less. The reaction time is, for example, 1 hour or more, preferably 5 hours or more, and for example, 48 hours or less, preferably 24 hours or less.

[0083] In this reaction, water produced by the esterification reaction is distilled off by a known method, if necessary.

[0084] In the above reaction, the above reaction catalyst can be added in an appropriate ratio, if necessary.

[0085] In this method, the reaction is stopped when the acid value of the resulting rosin-modified alkyd resin (secondary product) reaches a predetermined value.

[0086] That is, the acid value of the rosin-modified alkyd resin (secondary product) is determined by the ratio of each component of the resin raw materials. Therefore, the acid value of the rosin-modified alkyd resin (secondary product) at the end of the reaction is calculated from the ratio of each component of the resin raw materials, and when the acid value is reached, the reactor is cooled to stop the reaction.

[0087] The acid value of the rosin modified alkyd resin is, for example, 1 mgKOH / g or more, preferably 5 mgKOH / g or more, and for example, 30 mgKOH / g or less, preferably 20 mgKOH / g or less, more preferably 15 mgKOH / g or less.

[0088] The method for obtaining the rosin-modified alkyd resin is not limited to the above, and the rosin-modified alkyd resin can also be obtained by reacting each component of the resin raw material in multiple stages in an appropriate order or by reacting them all at once by a known method until the acid value falls within the above range.

[0089] If necessary, the resin raw materials can be reacted in the presence of a known solvent to prepare a rosin-modified alkyd resin in the form of a solution or dispersion.

[0090] The weight average molecular weight (standard polystyrene equivalent) of the rosin modified alkyd resin is, for example, 1,000 or more, preferably 3,000 or more, more preferably 5,000 or more, and for example, 100,000 or less, preferably 50,000 or less, more preferably 10,000 or less.

[0091] In addition, the softening point of the rosin-modified alkyd resin (measurement method: Mettler method) is, from the viewpoint of improving film-forming properties and improving the water resistance, gloss, and touch (tack resistance) of the coating film, for example, 70° C. or more, preferably 75° C. or more, and more preferably 80° C. or more, and for example, 120° C. or less, preferably 105° C. or less, and more preferably 90° C. or less.

[0092] The base resin may also contain other ink resins (ink resins other than the above rosin-modified alkyd resins) as optional components in order to obtain desired physical properties.

[0093] Other ink resins include known base resins, such as acrylic resin, styrene-modified acrylic resin, silicone acrylic resin, modified silicone acrylic resin, rosin phenol resin, rosin ester resin, terpene phenol resin, coumarone-indene resin, petroleum resin, epoxy resin, modified epoxy resin, polyester resin, vinyl acetate resin, ethylene-vinyl acetate resin, urethane resin, urea resin, melamine resin, cellulose resin, etc. These may be used alone or in combination of two or more kinds.

[0094] The content of the other ink resins is appropriately set within a range that does not impair the excellent effects of the present invention.

[0095] Examples of the aqueous dispersion medium include water and hydrophilic solvents that are miscible with water.

[0096] Examples of hydrophilic organic solvents include alcohols such as methanol and ethanol, ketones such as acetone, ethers such as dioxane and tetrahydrofuran, ether alcohols such as cellosolve and carbitol, ether alcohol acetates such as cellosolve acetate and carbitol acetate, nitriles such as acetonitrile, etc. These can be used alone or in combination of two or more kinds.

[0097] As the aqueous dispersion medium, preferably, water is used.

[0098] The emulsifier contains an anionic emulsifier and a nonionic emulsifier. When the emulsifier contains an anionic emulsifier, the particles of the base resin can be well formed in the aqueous dispersion medium. Also, when the emulsifier contains a nonionic emulsifier, the stability of the particles of the base resin can be improved.

[0099] The anionic emulsifier contains an oxyalkylene-containing anionic emulsifier as an essential component.

[0100] The oxyalkylene-containing anionic emulsifier is an anionic emulsifier that contains an oxyalkylene group in the molecule.

[0101] Examples of the oxyalkylene include oxyethylene, oxypropylene, oxytrimethylene, and oxybutylene.

[0102] These oxyalkylenes can be used alone or in combination of two or more kinds.

[0103] When two or more kinds of oxyalkylenes are used in combination, the oxyalkylenes may be block copolymerized or random copolymerized.

[0104] As the oxyalkylene, preferably, oxyethylene and oxypropylene are used, and more preferably, oxyethylene is used.

[0105] More specific examples of the oxyalkylene-containing anionic emulsifier include polyoxyalkylene alkyl ether sulfates, polyoxyalkylene aryl ether sulfates, polyoxyalkylene alkyl aryl ether sulfates, polyoxyalkylene alkyl ether phosphates, polyoxyalkylene alkyl aryl ether phosphates, and polyoxyalkylene alkyl ether carboxylates.

[0106] Examples of polyoxyalkylene alkyl ether sulfates include sodium polyoxyethylene octyl ether sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene isotridecyl ether sulfate, and sodium polyoxyethylene oleyl ether sulfate.

[0107] Examples of polyoxyalkylene aryl ether sulfates include sodium polyoxyethylene styryl phenyl ether sulfate.

[0108] Examples of polyoxyalkylene alkylaryl ether sulfates include sodium polyoxyethylene nonylphenyl ether sulfate.

[0109] Examples of polyoxyalkylene alkyl ether phosphates include polyoxyethylene oleyl ether phosphate, polyoxyethylene octadecyl ether phosphate, polyoxyethylene stearyl ether sodium phosphate, polyoxyethylene oleyl ether sodium phosphate, and polyoxyethylene isotridecyl ether phosphate.

[0110] Examples of the polyoxyalkylene aryl ether phosphates include polyoxyethylene phenyl ether phosphates.

[0111] Examples of the polyoxyalkylene alkyl ether carboxylates include sodium polyoxyethylene lauryl ether carboxylate.

[0112] These oxyalkylene-containing anionic emulsifiers can be used alone or in combination of two or more kinds.

[0113] As the oxyalkylene-containing anionic emulsifier, preferably, polyoxyalkylene alkyl ether sulfates and polyoxyalkylene alkyl ether phosphates are used.

[0114] The number of oxyalkylene units contained in one molecule of the oxyalkylene-containing anionic emulsifier is, from the viewpoint of particle stabilization, for example, 2 or more, preferably 4 or more, more preferably 8 or more, even more preferably 10 or more, and particularly preferably 15 or more, and from the viewpoint of water resistance, for example, 80 or less, preferably 60 or less, more preferably 30 or less, and even more preferably 18 or less.

[0115] The anionic emulsifier may contain, as an optional component, an anionic emulsifier that does not contain an oxyalkylene in the molecule (hereinafter, referred to as an oxyalkylene-free anionic emulsifier).

[0116] Examples of the oxyalkylene-free anionic emulsifier include alkylarylsulfonates such as dodecylbenzenesulfonate, etc. These oxyalkylene-free anionic emulsifiers can be used alone or in combination of two or more kinds.

[0117] The content of the non-oxyalkylene-containing anionic emulsifier is appropriately set within a range that does not impair the excellent effects of the present invention.

[0118] Preferably, the anionic emulsifier does not contain any non-oxyalkylene-containing anionic emulsifier and consists of an oxyalkylene-containing anionic emulsifier.

[0119] The nonionic emulsifier is selected so that the HLB value is adjusted to fall within the range described below.

[0120] Examples of the nonionic emulsifier include oxyalkylene-containing nonionic emulsifiers.

[0121] The oxyalkylene-containing nonionic emulsifier is a nonionic emulsifier that contains an oxyalkylene in the molecule.

[0122] In the oxyalkylene-containing nonionic emulsifier, examples of the oxyalkylene include oxyethylene, oxypropylene, oxytrimethylene, and oxybutylene.

[0123] These oxyalkylenes can be used alone or in combination of two or more kinds.

[0124] When two or more kinds of oxyalkylenes are used in combination, the oxyalkylenes may be block copolymerized or random copolymerized.

[0125] Preferred examples of the oxyalkylene include oxyethylene and oxypropylene.

[0126] More specific examples of the oxyalkylene-containing nonionic emulsifiers include polyoxyalkylene alkyl ethers, polyoxyalkylene aryl ethers, polyoxyalkylene alkylaryl ethers, polyoxyalkylene higher fatty acid esters and ether addition products thereof.

[0127] Examples of the polyoxyalkylene alkyl ethers include polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, and polyoxyethylene ceto oleyl ether.

[0128] Examples of the polyoxyalkylene aryl ethers include polyoxyethylene styryl phenyl ether.

[0129] Examples of polyoxyalkylene alkylaryl ethers include polyoxyethylene nonylphenyl ether.

[0130] Examples of polyoxyalkylene higher fatty acid esters include polyoxyethylene monolaurate, polyoxyethylene monooleate, and polyoxyethylene ceto monooleate.

[0131] Examples of the ether addition products of polyoxyalkylene higher fatty acid esters include reaction products of the above-mentioned polyoxyalkylene higher fatty acid esters with the above-mentioned polyhydric alcohols.

[0132] The oxyalkylene-containing nonionic emulsifiers further include, for example, ether addition products in which polyoxyalkylene is added to polyhydric alcohols, oils and fats, etc.

[0133] Further, examples of the oxyalkylene-containing nonionic emulsifier include copolymers of ethylene oxide and other alkylene oxides (hereinafter, referred to as EOAO copolymers).

[0134] Examples of other alkylene oxides include propylene oxide, trimethylene oxide, butylene oxide, etc. These can be used alone or in combination of two or more. As the other alkylene oxide, preferably, propylene oxide is used.

[0135] More specifically, the EOAO copolymer may be, for example, a copolymer of ethylene oxide and propylene oxide (hereinafter, EOPO copolymer), a copolymer of ethylene oxide and butylene oxide (hereinafter, EOBO copolymer), a copolymer of ethylene oxide and propylene oxide and butylene oxide (hereinafter, EOPOBO copolymer), etc. These may be used alone or in combination of two or more kinds.

[0136] In the EOAO copolymer, each polymer unit may be block copolymerized or random copolymerized.

[0137] As the EOAO copolymer, preferably, a copolymer of ethylene oxide and propylene oxide (EOPO copolymer) is used, and more preferably, a block copolymer of ethylene oxide and propylene oxide (EOPO block copolymer) is used.

[0138] In the block copolymer, the polymer block of ethylene oxide may be either single or multiple, and the polymer block of other alkylene oxide may be either single or multiple.

[0139] More specifically, for example, the EOPO block copolymer may be an EOPO block copolymer (H-(EO)-(PO)-OH) having one ethylene oxide polymer block (polyoxyethylene unit: (EO)) having x repeating units and one propylene oxide polymer block (polyoxypropylene unit: (PO)) having y repeating units.

[0140] The EOPO block copolymer may be, for example, an EOPO block copolymer (H-(EO)x-(PO)y-(EO)z-OH) having an ethylene oxide polymer block having a number of repeating units x (first polyoxyethylene unit: (EO)x), an ethylene oxide polymer block having a number of repeating units z (second polyoxyethylene unit: (EO)z), and a propylene oxide polymer block having a number of repeating units y (polyoxypropylene unit: (PO)y) contained between the ethylene oxide polymer blocks.

[0141] In the EOAO block copolymer, the number of repeating units and weight average molecular weight of the ethylene oxide and the number of repeating units and weight average molecular weight of the other alkylene oxide are appropriately set so that the HLB value falls within the range described below.

[0142] These oxyalkylene-containing nonionic emulsifiers can be used alone or in combination of two or more kinds.

[0143] As the oxyalkylene-containing nonionic emulsifier, preferably, polyoxyethylene alkyl ethers, copolymers of ethylene oxide and other alkylene oxides are used, more preferably, polyoxyethylene oleyl ether, block copolymers of ethylene oxide and propylene oxide are used, and further preferably, a combination of these is used.

[0144] In the oxyalkylene-containing nonionic emulsifier, the number (total amount) of repeating oxyalkylene units is appropriately set so that the HLB value falls within the range described below.

[0145] More specifically, the number of oxyalkylene units contained in one molecule of the oxyalkylene-containing nonionic emulsifier is, from the viewpoint of particle stabilization, for example, 20 or more, preferably 30 or more, more preferably 50 or more, and even more preferably 80 or more, and from the viewpoint of water resistance, for example, 500 or less, preferably 400 or less, more preferably 300 or less, and particularly preferably 150 or less.

[0146] Further, examples of the nonionic emulsifier include nonionic emulsifiers that do not contain oxyalkylene in the molecule (hereinafter, referred to as oxyalkylene-free nonionic emulsifiers).

[0147] The oxyalkylene-free nonionic emulsifier is not particularly limited, but examples thereof include esterification reaction products of higher fatty acids and polyglycerol, esterification reaction products of higher fatty acids and sucrose, and esterification reaction products of higher fatty acids and polysaccharides.

[0148] These oxyalkylene-free nonionic emulsifiers can be used alone or in combination of two or more kinds.

[0149] These nonionic emulsifiers can be used alone or in combination of two or more kinds.

[0150] The nonionic emulsifier preferably does not contain an oxyalkylene-free nonionic emulsifier and is composed of an oxyalkylene-containing nonionic emulsifier.

[0151] The HLB value of the nonionic emulsifier is, from the viewpoint of storage stability, 16.0 or more, preferably 16.5 or more, more preferably 17.0 or more, even more preferably 17.5 or more, and particularly preferably 18.0 or more, and from the viewpoint of water resistance, it is 20.0 or less, preferably 19.5 or less, and more preferably 19.0 or less.

[0152] The HLB value of the nonionic emulsifier is calculated by the Griffin method.

[0153] Furthermore, when two or more types of nonionic emulsifiers are used in combination, the HLB value is the HLB value of the total amount (mixture) of the nonionic emulsifiers.

[0154] In the emulsifier, the mass ratio of the anionic emulsifier to the nonionic emulsifier is not particularly limited, but for example, the anionic emulsifier is, for example, 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, and for example, 90% by mass or less, preferably 80% by mass or less, more preferably 70% by mass or less, based on the total amount of the anionic emulsifier and the nonionic emulsifier. Also, the nonionic emulsifier is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, and for example, 90% by mass or less, preferably 70% by mass or less, more preferably 50% by mass or less, even more preferably 45% by mass or less.

[0155] The resin composition for water-based ink of the present invention can be obtained by mixing the base resin, the aqueous dispersion medium, and the emulsifier (and further, a neutralizer and additives, if necessary) by a known method.

[0156] The content of the base resin relative to the total amount of the base resin, the aqueous dispersion medium, and the emulsifier is, for example, 30 mass% or more, preferably 40 mass% or more, and for example, 70 mass% or less, preferably 60 mass% or less.

[0157] Furthermore, the content of the aqueous dispersion medium relative to the total amount of the base resin, the aqueous dispersion medium, and the emulsifier is, for example, 30 mass% or more, preferably 40 mass% or more, and for example, 70 mass% or less, preferably 60 mass% or less.

[0158] Furthermore, the amount of the anionic emulsifier relative to the total amount of the base resin, the aqueous dispersion medium, and the emulsifier is, for example, 1 mass % or more, preferably 3 mass % or more, and for example, 10 mass % or less, preferably 5 mass % or less.

[0159] Furthermore, the amount of the nonionic emulsifier relative to the total amount of the base resin, the aqueous dispersion medium, and the emulsifier is, for example, 1 mass % or more, preferably 2 mass % or more, and for example, 10 mass % or less, preferably 7 mass % or less.

[0160] Further, on a solids basis, the anionic emulsifier is, for example, 2 parts by mass or more, preferably 6 parts by mass or more, and for example, 20 parts by mass or less, preferably 10 parts by mass or less, per 100 parts by mass of the base resin.

[0161] Furthermore, the amount of the nonionic emulsifier relative to 100 parts by mass of the base resin is, for example, 2 parts by mass or more, preferably 4 parts by mass or more, and for example, 20 parts by mass or less, preferably 14 parts by mass or less.

[0162] The base resin, the aqueous dispersion medium, and the emulsifier may be mixed in any manner known in the art without any particular limitations, so long as particles of the base resin can be formed and dispersed in the aqueous dispersion medium.

[0163] For example, first, the base resin is heated and melted, then an emulsifier is added to the molten resin and stirred, and then an aqueous dispersion medium is added to the mixture of the molten resin and the emulsion, whereby the particles of the base resin can be dispersed in the aqueous dispersion medium.

[0164] In the above method, for example, the anionic emulsifier and the nonionic emulsifier may be added simultaneously. Also, for example, the anionic emulsifier and a part of the nonionic emulsifier (preferably the anionic emulsifier) ​​may be added, and the aqueous dispersion medium may be mixed, and then the remaining part of the anionic emulsifier and the nonionic emulsifier (preferably the nonionic emulsifier) ​​may be added.

[0165] In the above method, if necessary, a neutralizing agent such as ammonia may be appropriately added to neutralize the anionic groups of the anionic emulsifier.

[0166] The pH of the resin composition for aqueous inks is, for example, 5.0 or more, preferably 6.0 or more, and for example, 9.0 or less, preferably 8.0 or less.

[0167] In the above method, the mixing efficiency can be improved by using a preheated aqueous dispersion medium, if necessary.

[0168] Furthermore, the resin composition for water-based inks may contain additives as necessary. Examples of additives include known additives such as pigment dispersants, drying agents, anti-sagging agents, rust inhibitors, plasticizers, coating surface conditioners (wax), antioxidants, ultraviolet absorbers, and surfactants. These may be used alone or in combination of two or more kinds. The ratio of additives added is appropriately set depending on the purpose and application.

[0169] In the aqueous ink resin composition, the solids concentration and viscosity are adjusted by adding or removing the aqueous dispersion medium as required.

[0170] The solids concentration of the aqueous ink resin composition is, for example, 20 mass % or more, preferably 30 mass % or more, and for example, 80 mass % or less, preferably 60 mass % or less.

[0171] The viscosity of the aqueous ink resin composition at 25° C. is, for example, 10 mPa·s or more, preferably 50 mPa·s or more, and for example, 2000 mPa·s or less, preferably 1000 mPa·s or less.

[0172] The viscosity is measured in accordance with the examples described below (the same applies hereinafter).

[0173] In the resin composition for aqueous inks, the average particle size of the rosin-modified alkyd resin (measurement method: laser diffraction method) is, for example, 0.01 μm or more, preferably 0.1 μm or more, and for example, 10 μm or less, preferably 1.0 μm or less.

[0174] In such a resin composition for a water-based ink, the base resin contains a rosin-modified alkyd resin. Since such a resin contains raw materials derived from plants, it can contribute to carbon neutrality.

[0175] In the above-mentioned resin composition for use in an aqueous ink, the base resin contains a rosin-modified alkyd resin. Since the rosin-modified alkyd resin contains raw materials derived from plants, the resin composition for use in an aqueous ink can contribute to carbon neutrality.

[0176] In the above-mentioned water-based ink resin composition, the emulsifier contains an anionic emulsifier containing an oxyalkylene in the molecule, so that particles of the rosin-modified alkyd resin are well formed in the water-based ink resin composition.

[0177] In addition, in the above-mentioned aqueous ink resin composition, the emulsifier contains a nonionic emulsifier having an HLB value in a predetermined range. Therefore, when used in an ink composition (described later), the stability of the rosin-modified alkyd resin particles can be improved. As a result, the aqueous ink resin composition of the present invention has excellent storage stability and excellent film-forming properties, and therefore the coating film has excellent water resistance.

[0178] The method for forming the coating film is not particularly limited, but first, an ink composition is prepared.

[0179] The ink composition is not particularly limited as long as it contains the above-mentioned resin composition for aqueous ink. For example, the above-mentioned resin composition for aqueous ink can be used as an ink composition (e.g., an overprint varnish) as it is.

[0180] Furthermore, the ink composition may contain a pigment, if necessary, in addition to the above-mentioned resin composition for a water-based ink.

[0181] Examples of pigments include known pigments such as carbon black, titanium oxide, calcium carbonate, iron oxide, barium sulfate, silica, clay, talc, quinacridone pigments, azo pigments, nitroso pigments, phthalocyanine pigments, etc. These pigments can be used alone or in combination of two or more kinds.

[0182] The pigment content (solid content) is, for example, 20 parts by mass or more, preferably 40 parts by mass or more, per 100 parts by mass of the base resin (solid content) in the aqueous ink resin composition, and for example, 150 parts by mass or less, preferably 120 parts by mass or less.

[0183] Furthermore, the ink composition preferably contains other ink resins (ink resins other than the above rosin-modified alkyd resin) in addition to the above water-based ink resin composition.

[0184] Other examples of the ink resin include the above-mentioned known base resins.

[0185] The content ratio of other ink resins is not particularly limited and may be appropriately set depending on the purpose and application.

[0186] As the other ink resin, preferably, a high acid value water-soluble resin is used, more specifically, a styrene-modified acrylic resin is used.

[0187] When a high acid value water-soluble resin is blended as another ink resin in the ink composition, the gloss of the coating film can be improved. On the other hand, when a high acid value water-soluble resin is blended, the stability of the rosin-modified alkyd resin particles is usually reduced, and the storage stability of the ink composition is reduced. However, if the ink composition contains the above-mentioned water-based ink resin composition, the rosin-modified alkyd resin particles can be improved, and excellent storage stability can be obtained even when a high acid value water-soluble resin is blended.

[0188] Furthermore, the ink composition may contain additives as necessary. Examples of additives include known additives such as pigment dispersants, drying agents, sagging prevention agents, rust inhibitors, plasticizers, coating surface conditioners (wax), antioxidants, ultraviolet absorbers, and surfactants. These may be used alone or in combination of two or more kinds. The ratio of additives added is appropriately set depending on the purpose and application.

[0189] In addition, in the ink composition, the solids concentration and viscosity are adjusted by adding or removing the above-mentioned aqueous dispersion medium, as necessary.

[0190] The solids concentration of the ink composition is, for example, 10 mass % or more, preferably 20 mass % or more, and for example, 80 mass % or less, preferably 60 mass % or less.

[0191] The ink composition has a viscosity at 25° C. of, for example, 10 mPa·s or more, preferably 50 mPa·s or more, and for example, 2000 mPa·s or less, preferably 1000 mPa·s or less.

[0192] The method for producing the coating film is not particularly limited, and the ink composition is applied to an object to be coated by a known method, and then dried.

[0193] The coating method is not particularly limited, and examples of the coating method that can be used include coating using equipment commonly used for coating, such as a roll coater, a bar coater, a doctor blade, a Mayer bar, and an air knife, and known coating methods such as screen printing, offset printing, flexographic printing, brush coating, spray coating, gravure coating, and reverse gravure coating.

[0194] The drying conditions are such that the drying temperature is, for example, 10° C. or more, preferably 20° C. or more, and for example, 90° C. or less, preferably 80° C. or less, and the drying time is, for example, 12 hours or more, preferably 24 hours or more.

[0195] This allows the ink composition to be cured, and as a result, a coating film is obtained as a cured product of the ink composition.

[0196] Such a coating film is obtained by curing an ink composition containing the above-mentioned resin composition for water-based inks, and therefore has excellent water resistance.

[0197] Therefore, the coating film is suitably used, for example, as a water-based flexographic ink or water-based gravure ink in coating food packaging materials. EXAMPLES

[0198] 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 based on mass unless otherwise specified. In addition, the 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 value (numerical value defined as "less than or equal to" or "less than") or lower limit value (numerical value defined as "more than or equal to" or "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Form for carrying out the invention".

[0199] Manufacturing Example 1 (Base Resin 1) To 55 parts of molten tall rosin, 14 parts of glycerin and 12 parts of soybean oil were added, and the mixture was heated to 240 to 260° C. to carry out condensation polymerization (dehydration reaction).

[0200] Next, when the acid value reached 10 mgKOH / g or less, the mixture was cooled to 150° C. or less, and then 19 parts of terephthalic acid was added, and the mixture was heated to 260 to 275° C. to carry out an esterification reaction.

[0201] This resulted in base resin 1 having an acid value of 18 mgKOH / g and a softening point (Mettler method) of 90° C. The proportion of aromatic dicarboxylic acid (terephthalic acid) relative to the resin raw material (solid content) of base resin 1 was 19 mass %.

[0202] In the above reaction, the equivalent ratio (hydroxyl group / carboxy group) of hydroxyl groups in glycerin (including glycerin derived from soybean oil) to the total amount of carboxyl groups derived from tall rosin, terephthalic acid, and fatty acids in soybean oil was 1.14.

[0203] Manufacturing Example 2 (Base Resin 2) To 65 parts of molten tall rosin, 14 parts of glycerin and 5 parts of soybean oil were added, and the mixture was heated to 240 to 260° C. to cause condensation polymerization (dehydration reaction).

[0204] Next, when the acid value reached 10 mgKOH / g or less, the mixture was cooled to 150° C. or less, and then 10 parts of terephthalic acid and 6 parts of adipic acid were added, and the mixture was heated to 260 to 275° C. to carry out an esterification reaction.

[0205] This resulted in a base resin 2 having an acid value of 12 mgKOH / g and a softening point (Mettler method) of 89° C. The proportion of aromatic dicarboxylic acid (terephthalic acid) relative to the resin raw material (solid content) of base resin 2 was 10 mass %.

[0206] In the above reaction, the equivalent ratio (hydroxyl group / carboxy group) of hydroxyl groups in glycerin (including glycerin derived from soybean oil) to the carboxy groups (total amount) derived from tall rosin, terephthalic acid, adipic acid, and fatty acids in soybean oil was 1.14.

[0207] Examples 1 to 13 and Comparative Examples 1 to 6 According to the formulations in Tables 1 to 4, resin compositions for water-based inks were obtained.

[0208] More specifically, for example, in Example 1, first, 1000 parts of the base resin was placed in a pressure-resistant reaction vessel and melted at 150 to 170°C.

[0209] Next, the molten base resin was cooled, and 30 parts (solid content equivalent) of an anionic emulsifier, 20 parts (solid content equivalent) of a nonionic emulsifier, and 2 parts of ammonia water (25%) were added at 135 to 150° C. Then, the mixture was cooled to around 100° C. while gradually increasing the stirring speed.

[0210] Next, heated water (boiled water) was gradually added as an aqueous dispersion medium to adjust the solid content to about 65 to 85 mass %.

[0211] Next, the stirring speed was increased while further adding hot water, and the solid content was adjusted to 48-55% by mass so that the viscosity became 200-400 mPa·s.

[0212] Thereafter, stirring was continued for about 5 to 10 minutes, and the mixture was cooled to room temperature.

[0213] As a result, a resin composition for a water-based ink was obtained.

[0214] The following emulsifiers were used as the anionic emulsifier and the nonionic emulsifier.

[0215] <Anionic emulsifier> A-1: Polyoxyethylene (EO15) isotridecyl (C13) ether sulfate sodium salt, EO unit number 15, solids concentration 100% A-2: Polyoxyethylene (EO9) isotridecyl (C13) ether phosphate, EO unit number 9, solids concentration 100% A-3: Polyoxyethylene (EO7) oleyl (C18) ether phosphate, EO unit number 7, solids concentration 100% A-4: Isotridecyl (C13) alcohol ether phosphate, EO unit number 0, solids concentration 100% A-5: Dodecylbenzenesulfonic acid, EO unit number 0, solid content concentration 100% A-6: Polyoxyethylene (EO20) isotridecyl (C13) ether phosphate, EO unit number 20, solids concentration 100% A-7: Isotridecyl (C13) alcohol ether sulfate, EO unit number 2, solids concentration 100% A-8: Isotridecyl (C13) alcohol ether sulfate, EO unit number 4, solids concentration 100% A-9: Isotridecyl (C13) alcohol ether sulfate, EO unit number 50, solids concentration 100%

[0216] <Nonionic emulsifier> N-1: Polyoxyethylene (EO80) oleyl (C18) alcohol, EO unit number 80, solids concentration 100%, HLB value 18.5 N-2: Block copolymer of ethylene oxide and propylene oxide (EOPO copolymer), number of EO units 300, weight average molecular weight of PO polymer block 3250, solid content concentration 100%, HLB value 16 N-3: Polyoxyethylene (EO35) oleyl (C18) alcohol, EO unit number 35, solids concentration 100%, HLB value 17.2 N-4: Polyoxyethylene (EO100) oleyl (C18) alcohol, EO unit number 100, solids concentration 100%, HLB value 19 N-5: Polyoxyethylene (EO60) cetooleyl (C17) alcohol, EO unit number 60, solids concentration 100%, HLB value 18.1 N-6: Polyoxyethylene (EO15) oleyl (C18) alcohol, EO unit number 15, solids concentration 100%, HLB value 15

[0217] <Evaluation> (1) Preparation of ink composition 15 parts of a styrene-modified acrylic resin (product name JONCRYL 61, manufactured by BASF, 35% aqueous ammonia solution) and 6 parts of a wax (product name Flexonix W 378E, manufactured by Lawter) serving as a coating surface conditioner were mixed at 200 rpm.

[0218] Next, 39 parts of a resin composition for water-based ink was added to the resulting mixture at 100 to 800 rpm, and further 35 parts of a pigment water dispersion (phthalocyanine blue PB-15:3, solid content 40%) was added.

[0219] Then, 5 parts of water was added at a stirring speed of 1000 rpm.

[0220] This gave 100 parts of an ink composition.

[0221] The solid content of the ink composition was about 40% by mass.

[0222] (2) Storage stability The ink composition was stored in a sealed container at room temperature, and the initial viscosity immediately after the preparation of the ink composition and the viscosity after two weeks of storage were measured, and the rate of change in viscosity (viscosity after storage / initial viscosity) was calculated.

[0223] The viscosity was measured under the following conditions.

[0224] Apparatus: Brookfield rotational viscometer (manufactured by Brookfield) Temperature: 25℃ Rotor: Spindle 2 Rotation speed: 100 rpm The storage stability was evaluated based on the rate of change in viscosity according to the following criteria.

[0225] A+: Viscosity change rate is less than 10%. A: Viscosity change rate is 10% or more but less than 15% A-: Viscosity change rate is between 15% and 20%. B: Viscosity change rate is 20% or more but less than 25%. B-: Viscosity change rate is 25% or more but less than 30%. C: Viscosity change rate is 30% or more. D: Test not possible (cannot be dispersed in water)

[0226] (3) Water resistance The ink composition was applied to a coated paper (100 g / m) using a bar coater (6 microns).2 ) and dried at 50°C for 30 seconds.

[0227] The water resistance of the coating surface was then tested (COBB test based on ISO535-1991).

[0228] More specifically, 100g of water is poured into a 100cm 2 The water was dropped onto the surface of the paper using a cylinder, and the water was wiped off after 10 minutes.

[0229] The difference in weight between the paper after wiping and the paper before the test was measured.

[0230] At this time, the smaller the difference in weight, the more excellent the water resistance of the coating film was evaluated.

[0231] The evaluation criteria are as follows.

[0232] A: Weight difference is 100g / m 2 less than. B: Weight difference is 100g / m 2 More than 120g / m 2 less than. C: Weight difference is 120g / m 2 The end. D: Test not possible (cannot be dispersed in water)

[0233] [Table 1]

[0234] [Table 2]

[0235] [Table 3]

[0236] [Table 4]

[0237] Details of the abbreviations in the table are given below.

[0238] AO: alkylene oxide EO: Ethylene oxide PO: Propylene oxide A-1: Polyoxyethylene (EO15) isotridecyl (C13) ether sulfate sodium salt, EO unit number 15, anionic emulsifier A-2: Polyoxyethylene (EO9) isotridecyl (C13) ether phosphate, EO unit number 9, anionic emulsifier A-3: Polyoxyethylene (EO7) oleyl (C18) ether phosphate, EO unit number 7, anionic emulsifier A-4: Isotridecyl (C13) alcohol ether phosphate, EO unit number 0, anionic emulsifier A-5: Dodecylbenzenesulfonic acid, EO unit number 0, anionic emulsifier A-6: Polyoxyethylene (EO20) isotridecyl (C13) ether phosphate, EO unit number 20, anionic emulsifier A-7: Isotridecyl (C13) alcohol ether sulfate, EO unit number 2, solids concentration 100%, anionic emulsifier A-8: Isotridecyl (C13) alcohol ether sulfate, EO unit number 4, solids concentration 100%, anionic emulsifier A-9: Isotridecyl (C13) alcohol ether sulfate, EO unit number 50, solids concentration 100%, anionic emulsifier N-1: Polyoxyethylene (EO80) oleyl (C18) alcohol, EO unit number 80, nonionic emulsifier, HLB value 18.5 N-2: Block copolymer of ethylene oxide and propylene oxide (EOPO copolymer), number of EO units 300, weight average molecular weight of PO polymer block 3250, nonionic emulsifier, HLB value 16 N-3: Polyoxyethylene (EO35) oleyl (C18) alcohol, EO unit number 35, nonionic emulsifier, HLB value 17.2 N-4: Polyoxyethylene (EO100) oleyl (C18) alcohol, EO unit number 100, nonionic emulsifier, HLB value 19 N-5: Polyoxyethylene (EO60) cetooleyl (C17) alcohol, EO unit number 60, nonionic emulsifier, HLB value 18.1 N-6: Polyoxyethylene (EO15) oleyl (C18) alcohol, EO unit number 15, nonionic emulsifier, HLB value 15 HLB: HLB value measured by the Griffin method

[0239] The above invention is provided as an exemplary embodiment of the present invention, but this is merely an example and should not be interpreted as being limited. Modifications of the present invention that are obvious to those skilled in the art are included in the scope of the following claims. [Industrial Applicability]

[0240] The water-based ink resin composition of the present invention is suitably used for coating food packaging materials.

Claims

1. The composition contains a base resin, an aqueous dispersion medium, and an emulsifier, The base resin contains a rosin-modified alkyd resin, The emulsifier contains an anionic emulsifier and a nonionic emulsifier, The anionic emulsifier comprises an oxyalkylene-containing anionic emulsifier, the oxyalkylene contained in the oxyalkylene-containing anionic emulsifier is oxyethylene, and the number of oxyalkylene units contained in one molecule of the oxyalkylene-containing anionic emulsifier is 2 or more and 50 or less; The nonionic emulsifier contains an oxyalkylene-containing nonionic emulsifier, The HLB value of the nonionic emulsifier is 16.0 or more and 20.0 or less. A resin composition for use in water-based inks, comprising:

2. 2. The resin composition for use in a water-based ink according to claim 1, wherein the number of oxyalkylene units contained in one molecule of the oxyalkylene-containing anionic emulsifier is 5 or more.

3. The number of oxyalkylene units contained in one molecule of the oxyalkylene-containing anionic emulsifier is 10 or more and 18 or less. The resin composition for use in a water-based ink according to claim 1 .

4. The number of oxyalkylene units contained in one molecule of the oxyalkylene-containing nonionic emulsifier is 30 or more. The resin composition for use in a water-based ink according to claim 1 .

5. The nonionic emulsifier is Contains a block copolymer of ethylene oxide and propylene oxide The resin composition for use in a water-based ink according to claim 1 .

6. The rosin-modified alkyd resin is a reaction product of a resin raw material containing rosin, fatty acid and / or fat, polybasic acid, and polyhydric alcohol. The resin composition for use in a water-based ink according to claim 1 .

7. The polybasic acid contains an aromatic dicarboxylic acid. The resin composition for use in a water-based ink according to claim 6 .

8. The content of the aromatic dicarboxylic acid is 11% by mass or more and 23% by mass or less based on the total amount of the resin raw material. The resin composition for use in a water-based ink according to claim 7 .

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