Water-based ink composition, water-based ink, coating, and use of water-based ink

Abstract

To provide a water-based ink composition which has excellent clarity of drawn lines and gives a coating film excellent in abrasion resistance, water resistance, dishwasher resistance, washing resistance and wet friction resistance. [Solution] An aqueous ink composition containing a pigment (A), water (B), a pigment dispersant (C), a silicone-based resin emulsion (D), and a styrene-(meth)acrylic resin emulsion (E), wherein the styrene-(meth)acrylic resin emulsion (E) has a minimum film-forming temperature of 0°C or higher and 35°C or lower, the solids content of the styrene-(meth)acrylic resin emulsion (E) is 15% by mass or higher and 67% by mass or lower based on the total mass of solids in the aqueous ink composition, and the mass ratio of the silicone-based resin emulsion (D) to the styrene-(meth)acrylic resin emulsion (E) ((D) / (E)) in terms of solids is 0.1 or higher and 1.8 or lower.

Description

[Technical Field]

[0001] The present invention relates to an aqueous ink composition capable of forming a coating film having excellent physical properties such as water resistance, abrasion resistance, etc. More specifically, the present invention relates to an aqueous ink composition that forms a coating film on a plastic, metal, or glass substrate using the aqueous ink composition, and that has excellent abrasion resistance or wet abrasion resistance, as well as excellent water resistance, dishwasher resistance, washing resistance, etc. [Background technology]

[0002] There are two types of ink: oil-based inks that use organic solvents, and water-based inks that mainly use water-based solvents. In recent years, there has been a growing trend toward more environmentally friendly and safer products, which has led to a desire for water-based inks with excellent physical properties. Furthermore, while water-based pigment inks have traditionally been used primarily on paper substrates, there is a growing demand for water-based inks that not only meet the physical properties required of paper substrates, but also form good ink films when coated on non-absorbent surfaces such as polyethylene terephthalate (PET) or polyethylene (PE).

[0003] Various aqueous pigment ink compositions have been proposed to date, including those that can be used on non-absorbent surfaces such as PET, despite being aqueous inks, or those that have water resistance. For example, an aqueous pigment ink composition that has excellent abrasion resistance when written on non-absorbent surfaces such as PET has been proposed (Patent Document 1). Also, an aqueous ink composition has been proposed that provides handwriting that is water-resistant, warm water-resistant, and abrasion-resistant when written on the surface of glass or ceramics (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-14769 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-105282 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, various studies have been conducted to improve the various physical properties of aqueous inks. However, the water resistance of the aqueous ink composition proposed in Patent Document 1 was not studied. Furthermore, the inventors have found a problem that the water-based ink composition proposed in Patent Document 2 has a certain degree of water resistance when immersed in water, but is not necessarily good in terms of water resistance under various conditions to which the aqueous ink may be exposed.

[0006] Therefore, an object of the present invention is to provide an aqueous ink composition which not only has the physical properties required for a paper substrate, but also allows the aqueous ink composition of the present invention to form a coating film without being repelled even on substrates other than paper, which are normally difficult to apply to, and which has excellent line clarity; and which provides a coating film formed on a paper substrate, a cloth substrate, or a non-absorbent surface such as polypropylene (PP), PET, glass, or metal, which has excellent abrasion resistance, water resistance, and dishwasher resistance, and in particular, on cloth substrates, has excellent washing resistance and wet friction resistance. [Means for solving the problem]

[0007] That is, according to the present invention, there are provided the following aqueous ink composition, aqueous ink, coating, and use of the aqueous ink. [1] A pigment (A), Water (B) and a pigment dispersant (C); a silicone resin emulsion (D); a styrene-(meth)acrylic resin emulsion (E); An aqueous ink composition comprising: the styrene-(meth)acrylic resin emulsion (E) has a minimum film-forming temperature of 0°C or higher and 35°C or lower; the solid content of the styrene-(meth)acrylic resin emulsion (E) is 15% by mass or more and 67% by mass or less based on the total mass of the solid contents of the aqueous ink composition; the mass ratio ((D) / (E)) of the silicone resin emulsion (D) to the styrene-(meth)acrylic resin emulsion (E) in terms of solid content is 0.1 or more and 1.8 or less; Aqueous ink compositions. [2] The solid content of the silicone resin emulsion (D) is 1% by mass or more and 13% by mass or less relative to the total mass of the water-based ink composition; the solid content of the styrene-(meth)acrylic resin emulsion (E) is 3% by mass or more and 30% by mass or less relative to the total mass of the aqueous ink composition; [1] The aqueous ink composition according to the present invention. [3] The solid content of the silicone resin emulsion (D) is 13% by mass or more and 30% by mass or less based on the total mass of the solid content of the aqueous ink composition. [1] or [2]. The aqueous ink composition according to [1] or [2]. [4] The glass transition temperature of the styrene-(meth)acrylic resin emulsion (E) is 0°C or higher and 40°C or lower. The aqueous ink composition according to any one of [1] to [3]. [5] The pigment dispersant (C) contains a dispersing resin made of a forming material containing at least one of a styrene-based monomer and a (meth)acrylic acid-based monomer, and at least one selected from the group consisting of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant; a mass ratio ((C) / (A)) of the pigment dispersant (C) to the pigment (A) in terms of solid content is 0.02 or more and 1.9 or less; The aqueous ink composition according to any one of [1] to [4]. [6] Further, a surface conditioner (F) is contained, the surface conditioner (F) is a surfactant, The solid content of the surface conditioner (F) is 0% by mass or more and 30% by mass or less relative to the total mass of the solid contents of the aqueous ink composition. The aqueous ink composition according to any one of [1] to [5]. [7] The surface conditioner (F) contains at least one of a fluorine-based surfactant and a polyether-modified siloxane-based surfactant. [6] The aqueous ink composition according to [6]. [8] Further, it contains an anti-drying agent. The aqueous ink composition according to any one of [1] to [7]. [9] Further, containing a coalescent, The aqueous ink composition according to any one of [1] to [8].

[10] The aqueous ink composition according to any one of [1] to [9], Water-based ink.

[11] Used for at least one application selected from flexographic ink, gravure ink, and inkjet ink,

[10] The water-based ink according to

[10] .

[12] Use of the water-based ink described in

[10] in any one of a swath pen, a direct ink pen, a spray coating agent, a stamp ink, and a ballpoint pen.

[13] A coated product using the water-based ink described in

[10] or

[11] .

[14] A coated product using any one of the coating materials described in

[12] . [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an aqueous ink composition that not only has the physical properties required for a paper substrate, but also allows the aqueous ink composition of the present invention to form a coating film without being repelled even on substrates other than paper, which are normally difficult to apply to, and which has excellent line clarity.Furthermore, when applied to a paper substrate or a cloth substrate, or when formed on a non-absorbent surface such as PP, PET, glass or metal, the aqueous ink composition has excellent abrasion resistance, water resistance, and dishwasher resistance, and in the case of a cloth substrate in particular, it has excellent washing resistance and wet friction resistance. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. The present inventors have investigated aqueous ink compositions that not only have the physical properties required for paper substrates, but also enable the aqueous ink composition of the present invention to form a coating film without being repelled even on substrates other than paper, which are normally considered difficult to apply to, and that have excellent line clarity, and that provide coating films formed on paper substrates, cloth substrates, etc., and on non-absorbent surfaces such as PP, PET, glass, and metal, which have excellent abrasion resistance, water resistance, and dishwasher resistance, and, in the case of cloth substrates in particular, excellent washing resistance and wet friction resistance. As a result, the inventors have found that when an aqueous ink composition contains a pigment, water, a pigment dispersant, and a silicone-based resin emulsion, and a styrene-(meth)acrylic resin emulsion having a minimum film-forming temperature within a certain range and a solids content within a certain range in the solids content of the aqueous ink composition, and the styrene-(meth)acrylic resin emulsion and the silicone-based resin emulsion are contained in a predetermined solids mass ratio, the aqueous ink composition not only has the physical properties required for a paper substrate, but also is capable of forming a coating film without being repelled even on substrates other than paper, which are normally considered difficult to form on, and the aqueous ink composition has excellent line clarity, and the aqueous ink composition has excellent abrasion resistance, water resistance, dishwasher resistance, and, particularly for fabric substrates, washing resistance and wet rub resistance. This has led to the present invention.

[0010] The term "aqueous" in the context of an aqueous ink composition refers to the inclusion of an aqueous medium. "Aqueous medium" refers to a liquid medium containing water. "Liquid medium" refers to a volatile liquid such as water or an organic solvent. The aqueous ink composition of this embodiment contains water as the primary liquid medium. "Volatile content" refers to volatile components, such as water or an organic solvent, contained in the aqueous ink composition. Specifically, the heat residue obtained by a measurement method conforming to JIS K 5601-1-2:2008 is defined as the solid content (also referred to as the non-volatile content), and the remaining components are defined as the volatile content. Furthermore, the term "emulsion" used in this embodiment refers to a liquid (water) in which a liquid (resin) with small particle sizes is dispersed, and includes what is called an aqueous dispersion of an aqueous polymer (resin). Both types of emulsions may be emulsified using an emulsifier (surfactant) or self-emulsified without the use of an emulsifier (surfactant).

[0011] <<Water-based ink composition>> The aqueous ink composition according to this embodiment contains a pigment (A), water (B), a pigment dispersant (C), a silicone-based resin emulsion (D), and a styrene-(meth)acrylic resin emulsion (E). The styrene-(meth)acrylic resin emulsion (E) has a minimum film-forming temperature of 0°C or higher and 35°C or lower, and the solid content of the styrene-(meth)acrylic resin emulsion (E) is 15% by mass or higher and 67% by mass or lower, based on the total mass of solids in the aqueous ink composition. The mass ratio of the silicone-based resin emulsion (D) to the styrene-(meth)acrylic resin emulsion (E) ((D) / (E)), calculated as solids, is 0.1 or higher and 1.8 or lower. The aqueous ink composition according to this embodiment will be described in detail below.

[0012] <Pigments> The pigment (A) constituting the aqueous ink composition according to this embodiment may be any conventionally known resin-dispersed pigment dispersed by a dispersing resin, and is not particularly limited. Examples of the pigment (A) include inorganic pigments such as carbon black, and organic pigments such as soluble azo pigments, insoluble azo pigments, high-molecular-weight azo pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, dioxazine pigments, diketopyrrolopyrrole pigments, quinophthalone pigments, methine-azomethine pigments, perylene pigments, perinone pigments, isoindolinone pigments, and isoindoline pigments.

[0013] The pigment content (pigment concentration) in the aqueous ink composition according to this embodiment is preferably from 0.1% to 25% by mass, both inclusive, of the total amount of the aqueous ink composition, in terms of the relationship between storage stability and the solubility of other components, and more preferably from 2% to 20% by mass, both inclusive, from the viewpoint of particularly improving color development, dispersibility, or storage stability. If the pigment content (pigment concentration) in the aqueous ink composition is less than 0.1% by mass, color development will be poor, whereas if it exceeds 25% by mass, dispersibility and storage stability will be poor.

[0014] When producing the aqueous ink composition according to this embodiment, it is preferable to use a pigment dispersion in which the pigment and the pigment dispersant described below are dispersed in water as a solvent at a high concentration. According to the inventors' investigations, the use of a pigment dispersion makes it possible to obtain an aqueous ink composition that is excellent in terms of color development and storage stability. The pigment concentration in the pigment dispersion used in this embodiment is preferably 5% by mass or more and 55% by mass or less, more preferably 10% by mass or more and 55% by mass or less, and from the viewpoint of particularly improving color development, dispersibility, or storage stability, even more preferably 12% by mass or more and 53% by mass or less. The dispersing resin used in this embodiment may be any of the dispersing resins listed below. Ion-exchanged water is preferably used as the water used to prepare the pigment dispersion. If the pigment concentration in the pigment dispersion is less than 5% by mass, color development will be poor, while if it exceeds 55% by mass, dispersibility and storage stability will be poor.

[0015] <Pigment dispersant> The pigment dispersant (C) used in this embodiment disperses the pigment and is used to improve color development or storage stability. The aqueous ink composition according to this embodiment uses a pigment dispersion in which the pigment described above is dispersed in water as a solvent. The pigment dispersant (C) used in this embodiment may be a dispersing resin or a surfactant.

[0016] The dispersion resin used in this embodiment may be a dispersion resin made of a forming material containing at least one of a styrene-based monomer and a (meth)acrylic acid-based monomer. Generally, the structure of a dispersion resin for dispersing a pigment consists of a pigment adsorption portion that contributes to pigment adsorption and a solvent affinity portion that has affinity for the solvent and contributes to dispersibility. If the molecular chain of the solvent affinity portion in the structure is long, the steric repulsion between pigment molecules increases, which tends to improve dispersion stability. However, on the other hand, the viscosity of the dispersion resin solution itself tends to increase, resulting in a high viscosity of the ink composition. In contrast, if the molecular chain of the solvent affinity portion in the structure is short, the viscosity of the dispersion resin solution itself decreases, but the steric repulsion between pigment molecules decreases, which tends to worsen pigment dispersibility. The dispersion resin used in this embodiment is preferably selected taking these points into consideration.

[0017] The pigment adsorption site in the dispersion resin structure used in this embodiment is not particularly limited and can be appropriately designed to suit the surface properties of the pigment to be dispersed. For example, it is preferable that the monomer forming the dispersion resin contains a monomer containing an acidic group, such as methacrylic acid (MAA) or acrylic acid (AAc). Furthermore, in order to disperse the pigment in water, these acidic groups must be neutralized with a base such as ammonia, potassium hydroxide, or sodium hydroxide.

[0018] The portions of the dispersion resin structure used in this embodiment other than the pigment adsorption portion may also be appropriately designed in consideration of the pigment adsorption portion described above, and are not particularly limited. Examples of monomers for the forming material include methacrylate monomers such as methyl methacrylate (MMA), benzyl methacrylate, hydroxyethyl methacrylate (HEMA), ethyl methacrylate (EMA), and 2-ethylhexyl methacrylate (2ehMA), acrylate monomers such as methyl acrylate, benzyl acrylate, hydroxyethyl acrylate, and ethyl acrylate, and addition-polymerizable monomers such as styrene (St).

[0019] The structure of the dispersion resin used in this embodiment is not particularly limited, and various structures can be used, such as a random structure, a graft structure, a block structure, a star structure, etc. Among these, a random structure or a block structure is preferred.

[0020] The number-average molecular weight of the dispersion resin used in this embodiment is preferably 5,000 or more and 25,000 or less from the viewpoint of improving the fluidity of the pigment dispersion or the stability of the pigment particles, and more preferably 7,000 or more and 22,000 or less from the viewpoint of particularly excellent fluidity of the pigment dispersion. If the number-average molecular weight is less than 5,000, the steric repulsion between the pigment particles becomes small, causing the pigment particles to aggregate and increasing the viscosity of the pigment dispersion. On the other hand, if the number-average molecular weight exceeds 25,000, the viscosity of the dispersion resin solution itself becomes high, increasing the viscosity of the pigment dispersion.

[0021] As the pigment dispersant (C) used in this embodiment, a surfactant can be used for the purpose of dispersing. The surfactant is not particularly limited, and for example, a conventionally known surfactant can be used. Examples of the surfactant include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants. Examples of the surfactant include acetylene glycol surfactants, fluorine-based surfactants, alkylene oxide surfactants, hydrocarbon surfactants, and polyether-modified siloxane surfactants. As the pigment dispersant (C) used in this embodiment, one of the above surfactants may be used alone, or two or more may be used in combination. Among these, from the viewpoint of superior pigment dispersing action, any one of anionic surfactants, nonionic surfactants, and amphoteric surfactants is preferred.

[0022] Examples of anionic surfactants include saturated or unsaturated fatty acid salts (e.g., sodium laurate, sodium stearate, sodium oleate, and sodium linolenate), alkyl sulfates, alkylbenzenesulfonic acids (e.g., hexylbenzenesulfonic acid, octylbenzenesulfonic acid, and dodecylbenzenesulfonic acid) and salts thereof, polyoxyalkylene alkyl ether sulfates, polyoxyalkylene alkenyl ether sulfates, polyoxyethylene alkyl sulfate ester salts, sulfosuccinic acid alkyl ester salts, polyoxyalkylene sulfosuccinic acid alkyl ester salts, polyoxyalkylene alkylphenyl ether sulfates, alkanesulfonates, octyltrimethylammonium hydroxide, dodecyltrimethylammonium hydroxide, Examples of suitable salts include alkyl sulfonates, polyoxyethylene alkylphenyl ether sulfates, polyoxyalkylene alkyl ether acetates, alkyl phosphates, polyoxyalkylene alkyl ether phosphates, acyl glutamates, α-acyl sulfonates, alkyl sulfonates, alkyl aryl sulfonates, α-olefin sulfonates, alkyl naphthalene sulfonates, alkanesulfonates, alkyl or alkenyl sulfates, alkyl amide sulfates, alkyl or alkenyl phosphates, alkyl amide phosphates, alkylyl alkyl taurines, N-acyl amino acid salts, sulfosuccinates, alkyl ether carboxylates, amide ether carboxylates, α-sulfofatty acid ester salts, alanine derivatives, glycine derivatives, and arginine derivatives. Examples of suitable salts include alkali metal salts such as sodium salts, alkaline earth metal salts such as magnesium salts, alkanolamine salts such as triethanolamine salts, and ammonium salts.

[0023] Nonionic surfactants include polyoxyalkylene ethers, polyoxyalkylene alkyl ethers, polyoxyalkylene fatty acid esters, polyoxyalkylene fatty acid diesters, polyoxyalkylene resin acid esters, polyoxyalkylene (hydrogenated) castor oils, polyoxyalkylene alkylphenols, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene phenylphenyl ethers, polyoxyalkylene alkyl esters, polyoxyalkylene alkyl esters, sorbitan fatty acid esters, and polyoxyalkylene sorbitan alkyl esters. , polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene glycerin fatty acid esters, polyglycerin alkyl ethers, polyglycerin fatty acid esters, sucrose fatty acid esters, fatty acid alkanolamides, alkyl glucosides, polyoxyalkylene fatty acid bisphenyl ethers, polypropylene glycol, diethylene glycol, fluorine-based surfactants, polyoxyethylene-polyoxypropylene block polymers, and alkyl polyoxyethylene-polyoxypropylene block polymer ethers.

[0024] Examples of amphoteric surfactants include imidazoline-type, amidobetaine-type, alkylbetaine-type, alkylamidobetaine-type, alkylsulfobetaine-type, amidosulfobetaine-type, hydroxysulfobetaine-type, carbobetaine-type, phosphobetaine-type, aminocarboxylic acid-type, and amidoamino acid-type amphoteric surfactants. Specific examples include imidazoline-type amphoteric surfactants such as 2-undecyl-N,N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium and 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt; alkylbetaine-type amphoteric surfactants such as lauryl dimethylaminoacetic acid betaine and myristyl betaine; coconut oil fatty acid amidopropyl dimethylaminoacetic acid betaine, palm kernel oil fatty acid amidopropyl dimethylaminoacetic acid betaine, beef tallow fatty acid amidopropyl dimethylaminoacetic acid betaine, hardened beef tallow fatty acid amidopropyl dimethylaminoacetic acid betaine, laurin Amidobetaine-type amphoteric surfactants such as amidopropyl dimethylaminoacetic acid betaine, myristate amidopropyl dimethylaminoacetic acid betaine, palmitate amidopropyl dimethylaminoacetic acid betaine, stearate amidopropyl dimethylaminoacetic acid betaine, and oleate amidopropyl dimethylaminoacetic acid betaine; alkyl sulfobetaine-type amphoteric surfactants such as coconut oil fatty acid dimethyl sulfopropyl betaine; alkyl hydroxy sulfobetaine-type amphoteric surfactants such as lauryl dimethylaminohydroxy sulfobetaine; phosphobetaine-type amphoteric surfactants such as lauryl hydroxyphosphobetaine; andN-Lauroyl-N'-hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-oleoyl-N'-hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-Cocoyl-N'-hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-Lauroyl-N'-hydroxyethyl-N'-carboxymethylethylenediamine potassium, N-Oleoyl-N'-hydroxyethyl-N'-carboxymethylethylenediamine potassium, N-Lauroyl-N'-hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-Oleoyl-N'-hydroxyethyl-N'-carboxymethylethylenediamine sodium Examples of such surfactants include amide amino acid amphoteric surfactants, such as N'-carboxymethylethylenediamine sodium, N-cocoyl-N-hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-lauroyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine monosodium, N-oleoyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine monosodium, N-cocoyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine monosodium, N-lauroyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine disodium, N-oleoyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine disodium, and N-cocoyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine disodium;

[0025] The surfactants described above may be synthesized by known methods or commercially available products. Commercially available anionic surfactants include Demol N, RN, NL, RNL, T, T-45, MS, and P (manufactured by Kao Corporation), SN Wet 970 (manufactured by San Nopco), Ionet D-2, Sunseparator 100 (manufactured by Sanyo Chemical Industries, Ltd.), and Newcol 220-L(20)D (manufactured by Nippon Nyukazai Co., Ltd.). Commercially available nonionic surfactants include Emulgen 103 (manufactured by Kao Corporation), Newcol 610 and 1006 (manufactured by Nippon Nyukazai Co., Ltd.), and Surfynol CT151 (manufactured by Nissin Chemical Industry Co., Ltd.). Commercially available amphoteric surfactants include Levon 2000, 2000L, HC-30W, MY-30W, T-2, and Piuceria AMC (manufactured by Sanyo Chemical Industries, Ltd.), and Anhithol 20BS, 24B, 20N, 20HD, 20AB, and 55AB (manufactured by Kao Corporation).

[0026] When preparing the aqueous ink composition according to this embodiment using the pigment dispersion liquid described above, the dispersion resin solution having the above-described structure is neutralized with an alkali before use. The alkali used for neutralization in this case is not particularly limited, but examples thereof include ammonia, primary, secondary, or tertiary organic amines (including basic nitrogen-containing heterocyclic compounds), and compounds such as alkali metal hydroxides. These may be used alone or in combination of two or more.

[0027] The mass ratio ((C) / (A)) of the pigment dispersant (C) to the pigment (A) in terms of solid content is preferably 0.01 or more and 2.1 or less, and more preferably 0.02 or more and 1.9 or less from the viewpoint of particularly improving abrasion resistance, water resistance, washing resistance, wet friction resistance, dispersibility, storage stability, color development, or viscosity. From the viewpoint of particularly improving PP abrasion resistance, water resistance, dishwasher resistance, washing resistance, wet friction resistance, dispersibility, storage stability, color development, or viscosity, it is even more preferably 0.04 or more and 1.6 or less, and particularly preferably 0.04 or more and 1.0 or less. By setting the mass ratio ((C) / (A)) of the pigment dispersant (C) to the pigment (A) in terms of solid content within the above range, excellent abrasion resistance, water resistance, washing resistance, or wet friction resistance is achieved. If the mass ratio is less than 0.01, the viscosity is poor. If it exceeds 2.1, the color development is poor.

[0028] <Silicone resin emulsion> The water-based ink composition according to this embodiment is characterized in that it contains a silicone-based resin emulsion (D) and a styrene-(meth)acrylic resin emulsion (E) described below in combination at a specific ratio in the pigment dispersion described above. This silicone-based resin emulsion (D) tends to form a good ink film and improve its abrasion resistance. As used herein, "silicone-based resin emulsion" refers to a resin emulsion having a polysiloxane skeleton in the resin skeleton.

[0029] The silicone resin emulsion used in this embodiment may be synthesized by a known method or may be a commercially available product such as those listed below. Specific examples include NANOFINE KPX-02-04, NANOFINE KPX-97-048, and NANOFINE KPX-97-051 (all trade names, manufactured by Toyochem Co., Ltd.), which are acrylic emulsions composited with oligomers having a polysiloxane skeleton, 52 Additive and BY22-050A (all trade names, manufactured by Dow Corning Toray Co., Ltd.), which are silicone emulsions having silanol groups, and nonionic emulsions such as X-52-2160 (manufactured by Shin-Etsu Chemical Co., Ltd.) and Rheoflow DM S-55 (manufactured by Lion Corporation).

[0030] The solids content of the silicone resin emulsion (D) constituting the aqueous ink composition according to this embodiment is preferably 1% by mass or more and 13% by mass or less, more preferably 1% by mass or more and 10% by mass or less, based on the total mass of the aqueous ink composition. Furthermore, 1% by mass or more and 9.5% by mass or less is even more preferable, since this can provide a coating film with particularly excellent line clarity, abrasion resistance, or water resistance. By using a content within this range, a coating film using the aqueous ink composition according to this embodiment can have excellent abrasion resistance, water resistance, dishwasher resistance, or wet rub resistance, and can also provide clearer drawn lines. If the solids content of the silicone resin emulsion (D) based on the total mass of the aqueous ink composition is less than 1% by mass, the abrasion resistance, water resistance, or wet rub resistance will be poor, and if it exceeds 13% by mass, the line clarity, abrasion resistance, water resistance, or wet rub resistance will be poor.

[0031] The solids content of the silicone resin emulsion (D) in the solids of the aqueous ink composition according to this embodiment is preferably from 1 to 40% by mass, more preferably from 5 to 35% by mass, based on the total mass of the solids of the aqueous ink composition. Since this provides particularly excellent water resistance, it is even more preferable for the solids content of the silicone resin emulsion (D) to be from 13 to 30% by mass. If the solids content of the silicone resin emulsion (D) is within the above range, the water resistance, abrasion resistance, dishwasher resistance, wet rub resistance, and sharpness of drawn lines of the coating film can be further improved. If the solids content of the silicone resin emulsion (D) in the solids of the aqueous ink composition is less than 1% by mass, the abrasion resistance, water resistance, dishwasher resistance, and wet rub resistance are inferior, and if it exceeds 40% by mass, the sharpness of drawn lines, abrasion resistance, water resistance, and wet rub resistance are inferior.

[0032] <Styrene-(meth)acrylic resin emulsion> The styrene-(meth)acrylic resin emulsion (E) used in this embodiment is used for the purpose of improving the scratch resistance and water resistance of the coating film. The styrene-(meth)acrylic resin emulsion (E) used in this embodiment is not particularly limited, but examples thereof include resins obtained by polymerizing a styrene-based monomer and a monofunctional (meth)acrylic monomer. Note that "(meth)acrylic" is a concept that encompasses both "acrylic" and "methacrylic."

[0033] The styrene-based monomer is not particularly limited, but examples thereof include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, 4,α-dimethylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, 2,4,6-trimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-pentylstyrene, pn-hexylstyrene, pn-heptylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decanylstyrene, pn-dodecylstyrene, p-phenylstyrene, and 3,4-dicyclosilstyrene. In the aqueous ink composition according to this embodiment, one of the above styrene-based monomers may be used alone, or two or more may be used in combination.

[0034] The monofunctional (meth)acrylic monomer is not particularly limited, but examples thereof include acrylic monomers such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n-octadecyl acrylate, methyl α-chloroacrylate, and ethyl α-chloroacrylate; and methacrylic monomers such as methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-cyclohexyl methacrylate, n-dodecyl methacrylate, n-tridecyl methacrylate, and n-octadecyl methacrylate. In the water-based ink composition according to this embodiment, one of the monofunctional (meth)acrylic monomers described above may be used alone, or two or more of them may be used in combination.

[0035] The minimum film-forming temperature (hereinafter also referred to as MFT) of the styrene-(meth)acrylic resin emulsion (E) used in this embodiment must be 0°C or higher and 35°C or lower. By setting the minimum film-forming temperature within the above range, water resistance and dishwasher resistance can be improved, and excellent coating film formation is achieved. If the minimum film-forming temperature is lower than 0°C, the coating film will have poor water resistance and stickiness. On the other hand, if the minimum film-forming temperature is higher than 35°C, coating film formation will be difficult, and water resistance and PP dishwasher resistance will be poor. The minimum film-forming temperature can be measured in accordance with JIS K 6828-1:2003 using a TP-801MFT tester manufactured by Tester Sangyo Co., Ltd.

[0036] The glass transition temperature (hereinafter also referred to as Tg) of the styrene-(meth)acrylic resin emulsion (E) used in this embodiment is preferably from 0°C to 40°C, more preferably from 1°C to 40°C. By setting the glass transition temperature of the styrene-(meth)acrylic resin emulsion (E) within the above range, the water resistance of the coating film, coating film formation, and stickiness of the coating film can be improved. If the glass transition temperature is below 0°C, the coating film will have poor water resistance and will remain sticky. On the other hand, if the glass transition temperature is above 40°C, it will be difficult to form a coating film. The glass transition temperature is determined in accordance with JIS K 7121 using a differential scanning calorimeter, from the intersection point between the baseline and the tangent to the endothermic curve in a curve (DSC curve) obtained by heating 10 mg of a sample from -100°C to 160°C at a rate of 20°C / min.

[0037] The styrene-(meth)acrylic resin emulsion (E) used in this embodiment may be synthesized by a known method or may be a commercially available product, such as Polysol F600S (manufactured by Resonac Corporation), Nikasol RX-284SD (manufactured by Nippon Carbide Industries Co., Ltd.), Yodosol AA76 (manufactured by Henkel Japan), Ultrasol A-50 and KD-74 (manufactured by Aica Kogyo Co., Ltd.), Boncoat NST-100EF (manufactured by DIC Corporation), Bonlon PS-002 (manufactured by Mitsui Chemicals, Inc.), Neocryl A-655, A-1094, A-2092, and XK-188 (manufactured by Covestro Coating Resins), and NE2260 (manufactured by Seiko PMC Corporation).

[0038] The solids content of the styrene-(meth)acrylic resin emulsion (E) used in this embodiment is preferably 3% by mass or more and 30% by mass or less, relative to the total mass of the aqueous ink composition, and more preferably 3.8% by mass or more and 26% by mass or less, from the viewpoint of improving abrasion resistance or water resistance. Setting the solids content of the styrene-(meth)acrylic resin emulsion (E) relative to the total mass of the aqueous ink composition within the above range is preferred from the viewpoint of film formation and the viewpoint of improving line clarity, abrasion resistance, water resistance, dishwasher resistance, washing resistance, and wet rub resistance. If the solids content of the styrene-(meth)acrylic resin emulsion (E) relative to the total mass of the aqueous ink composition is less than 3% by mass, the abrasion resistance, water resistance, dishwasher resistance, washing resistance, and wet rub resistance will be poor. If it exceeds 30% by mass, the line clarity and abrasion resistance will be poor.

[0039] The solid content of the styrene-(meth)acrylic resin emulsion (E) used in this embodiment must be 15% by mass or more and 67% by mass or less, relative to the total mass of solids in the aqueous ink composition. By setting the solid content of the styrene-(meth)acrylic resin emulsion (E) relative to the total mass of solids in the aqueous ink composition within the above range, it is possible to improve abrasion resistance. If the solid content of the styrene-(meth)acrylic resin emulsion (E) relative to the total mass of solids in the aqueous ink composition is less than 15% by mass, the abrasion resistance, water resistance, dishwasher resistance, washing resistance, and wet rub resistance will be poor. If it exceeds 67% by mass, the clarity of drawn lines or abrasion resistance will be poor. From the same viewpoint, the solid content of the styrene-(meth)acrylic resin emulsion (E) relative to the total mass of solids in the aqueous ink composition is preferably 18% by mass or more and 66% by mass or less, and more preferably 18% by mass or more and 64% by mass or less from the viewpoint of particularly improving the abrasion resistance, water resistance, dishwasher resistance, or washing resistance of PP, metal, and glass.

[0040] In this embodiment, the mass ratio ((D) / (E)) of the silicone resin emulsion (D) to the styrene-(meth)acrylic resin emulsion (E) must be 0.1 or more and 1.8 or less. By setting the mass ratio ((D) / (E)) of the silicone resin emulsion (D) to the styrene-(meth)acrylic resin emulsion (E) within the above range, the abrasion resistance or water resistance of metal and glass can be improved. If the mass ratio ((D) / (E)) is less than 0.1, the abrasion resistance, water resistance, and wet rub resistance will be poor. If the mass ratio ((D) / (E)) is more than 1.8, the clarity of the drawn lines, abrasion resistance, wet rub resistance, and water resistance will be poor. The mass ratio ((D) / (E)) is preferably 0.1 or more and 1.5 or less, and more preferably 0.2 or more and 1.2 or less, since this particularly improves the abrasion resistance, water resistance, dishwasher resistance, washing resistance, or wet friction resistance of PP, metal, and glass.

[0041] The water-based ink composition according to this embodiment may contain not only the silicone-based resin emulsion (D) and the styrene-(meth)acrylic resin emulsion (E), but also other resins as long as they do not affect the present invention. Examples of other resins include acrylic resins other than styrene-(meth)acrylic resins, urethane resins, olefin resins, and versatate vinyl ester resins.

[0042] <Surface conditioner> The aqueous ink composition according to this embodiment may contain a surface conditioner (F). The surface conditioner is used for the purpose of surface conditioning, more specifically, for imparting wettability. The surface conditioner (F) may have a dispersing effect, and in addition to the dispersing effect, it also has a surface conditioning effect.

[0043] The surface conditioner (F) used in this embodiment may be, for example, a conventionally known surfactant, but is not particularly limited thereto. Examples of surfactants include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants. Examples of surfactants include acetylene glycol-based surfactants, fluorine-based surfactants, alkylene oxide-based surfactants, hydrocarbon-based surfactants, and polyether-modified siloxane-based surfactants. As the surface conditioner (F) used in this embodiment, one of the above surfactants may be used alone, or two or more may be used in combination. In particular, it is preferable that the surface conditioner (F) contains at least one of a fluorine-based surfactant and a polyether-modified siloxane-based surfactant from the viewpoint of imparting wettability.

[0044] Examples of fluorine-based surfactants include perfluoroalkyl surfactants such as hexafluoropropene and tetrafluoroethylene surfactants, and perfluoroalkenyl surfactants.

[0045] Furthermore, examples of the polyether-modified siloxane surfactant include polyether-modified siloxane surfactants such as dimethylpolysiloxane.

[0046] The surfactants described above may be synthesized by known methods or may be commercially available products. Commercially available fluorine-based surfactants include Fluorad FC-430 and 431 (manufactured by 3M Japan), Megafac F-444, 472, 477, 552, 553, 554, 443, 470, 475, 482, 483, 489, and 30 (manufactured by DIC Corporation), Asahiguard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, and SC-106 (manufactured by AGC Corporation), and the like. Commercially available polyether-modified siloxane surfactants include BYK-345, BYK-346, BYK-347, BYK-348, BYK-3450, and UV3530 (all manufactured by BYK Japan).

[0047] The solid content of the surface conditioner (F) used in this embodiment is preferably 0% by mass or more and 10% by mass or less, relative to the total mass of the aqueous ink composition, and more preferably 0% by mass or more and 5% by mass or less, from the viewpoint of particularly excellent water resistance or wet rub resistance. By setting the solid content of the surface conditioner (F) relative to the total mass of the aqueous ink composition within the above range, it is possible to improve the clarity of drawn lines and repelling. If it exceeds 10% by mass, water resistance or wet rub resistance will be poor.

[0048] The solid content of the surface conditioner (F) used in this embodiment is preferably 0% by mass or more and 40% by mass or less, more preferably 0% by mass or more and 30% by mass or less, relative to the total mass of solids in the aqueous ink composition, and even more preferably 0% by mass or more and 20% by mass or less, from the viewpoint of particularly excellent water resistance and wet rub resistance. By setting the solid content of the surface conditioner (F) relative to the total mass of solids in the aqueous ink composition within the above range, the clarity of drawn lines and repelling can be improved. If it exceeds 30% by mass, water resistance and wet rub resistance will be inferior.

[0049] <Other additives> The aqueous ink composition according to this embodiment may contain additives such as film-forming aids and drying inhibitors, as needed. Non-limiting examples of additives include plasticizers, antiblocking agents, antisettling agents, leveling agents, antifoaming agents, matting agents, pH adjusters, antioxidants, UV absorbers, light stabilizers, preservatives, antifungal agents, rust inhibitors, flame retardants, color developers, chelating agents, thickening inhibitors, and coupling agents. These additives may be used alone or in combination.

[0050] <Film-forming agent> The use of a coalescent in the aqueous ink composition of this embodiment can improve the film-forming properties of the emulsion in the composition. As mentioned above, it is preferable to use a coalescent and design the aqueous ink composition of this embodiment so that the binder resin forms a film at room temperature, ensuring an MFT of 25°C (room temperature) or less. In other words, if configured in this manner, the formed coating film will have excellent abrasion resistance, and when used with a padded felt-tip pen, the drawn lines will also have excellent abrasion resistance. Examples of coalescents include benzyl alcohol, 3-methoxy-3-methylbutanol, hexylene glycol, diethylene glycol mono-n-butyl ether, butyl cellosolve acetate, diethylene glycol mono-ethyl ether, butyl carbitol, ethyl cellosolve, carbitol acetate, butyl carbitol acetate, butyl cellosolve, ethylene glycol mono-n-ethyl ether, ethylene glycol mono-n-butyl ether, and ethylene glycol methyl ether acetate.

[0051] <Anti-drying agent> It is preferable to add a hydrophilic solvent as an anti-drying agent to the aqueous ink composition according to this embodiment. Examples of the anti-drying agent include polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters, urea, thiourea, ethylene urea, or derivatives thereof, ethylene glycol, polyethylene glycol, glycerin, propylene glycol, diethylene glycol, ethylene glycol monophenyl ether, propylene glycol monophenyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monoethyl ether. These may be used alone or in combination of two or more.

[0052] <Application> The aqueous ink composition according to this embodiment can be suitably used in stationery inks, plastic paints, architectural paints, gravure inks, flexographic inks, inkjet inks, and the like. Among these, it is particularly suitable for use as a stationery ink. Lines drawn using the aqueous ink composition according to this embodiment on stationery are not repelled by non-absorbent surfaces such as glass and metal surfaces, as well as plastics such as PP and PET. They can also be drawn on leather products, polystyrene foam, paper, and the like, and the drawn lines exhibit excellent abrasion resistance and water resistance. Furthermore, when the aqueous ink composition according to this embodiment is applied to plastic products, glass products, metal products, and the like, which are typically difficult to print with aqueous inks, the resulting coated products exhibit excellent abrasion resistance, water resistance, dishwasher resistance, washing resistance, and wet friction resistance. The coated products may also be printed products. Using the aqueous ink composition according to this embodiment as a flexographic ink or gravure ink is also a preferred embodiment.

[0053] The coating method when using the aqueous ink of the aqueous ink composition according to this embodiment as a coating material for the above-mentioned plastic coating material, architectural coating material, etc. is not particularly limited. Examples include a spray method, and coating methods using a brush, roller, or coater.

[0054] When the aqueous ink made from the aqueous ink composition according to this embodiment is used as the above-mentioned stationery ink, it can be suitably used, more specifically, in felt-tip pens, markers, ballpoint pens, brush pens, or stamp inks (wherein the aqueous ink made from the aqueous ink composition according to this embodiment is absorbed into an ink reservoir such as felt or sponge). A so-called felt-tip pen is a pen that uses a fibrous nib and guides ink from an ink reservoir in the pen body to the nib by capillary action, leading to writing. There are two types of felt-tip pens: direct ink type and swath type, depending on the structure of the ink reservoir. The direct ink type is a type in which an ink tank is mounted on the pen body and ink is stored directly in this ink tank. On the other hand, the swath type is a type in which ink is filled into cotton pads built into the pen body and a fibrous nib is attached directly to the cotton pads, and writing is performed by allowing the ink filled in the cotton pads to soak into the nib by capillary action. [Example]

[0055] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" and "%" are by mass unless otherwise specified.

[0056] In the examples and comparative examples, a polymer having the following monomer composition and the following solvent was used as the dispersion resin in the form of a solution, which will be hereinafter referred to as the "dispersion resin solution."

[0057] (Dispersion resin solution-1 (styrene acrylic acid dispersion resin)) Random polymer Monomer composition: styrene (St) / methyl methacrylate (MMA) / ethyl methacrylate (EMA) / 2-ethylhexyl methacrylate (2EHMA) / hydroxyethyl methacrylate (HEMA) / methacrylic acid (MAA) = 20 / 15 / 15 / 20 / 20 / 10, number average molecular weight 18,000, molecular weight distribution 2.08 ·solvent A mixed solvent of diethylene glycol mono-normal butyl ether (BDG) / propylene glycol methyl ether (MPG) / water / aqueous ammonia (28%) = 50 / 50 / 70 / 7.7 for 100 parts by mass of polymer pH: 8.7 Solids content: 36% (Dispersion resin solution-2 (acrylic acid-based dispersion resin)) AB block copolymer Monomer composition: benzyl methacrylate (BzMA) / cyclohexyl methacrylate (CHMA) (A chain)-b-BzMA / MAA (B chain) = 19.8 / 23.7-b-33.8 / 22.7 Number average molecular weight of A chain: 5000, molecular weight distribution: 1.20, number average molecular weight of B: 5700, number average molecular weight of AB block copolymer: 10700, molecular weight distribution: 1.31 ·solvent A mixed solvent of BDG / MPG / water / aqueous ammonia (28%) = 50 / 50 / 182.4 / 17.6 for 100 parts by mass of polymer pH: 8.9 Solids content 25.0% (Dispersion resin solution-3 (acrylic acid-based dispersion resin)) AB block copolymer Monomer composition: CHMA / BzMA (A chain)-b-CHMA / MMA / MAA (B chain) = 39.8 / 16.7-b-10.6 / 12.6 / 20.3 Number average molecular weight of A chain: 4700, molecular weight distribution: 1.31, number average molecular weight of B: 4400, number average molecular weight of AB block copolymer: 9100, molecular weight distribution: 1.39 ·solvent A mixed solvent of BDG / water / sodium hydroxide = 100 / 250 / 9.5 for 100 parts by mass of polymer pH: 9.9 Solids content: 22.9%

[0058] <Preparation Example 1> 114 parts of the above-mentioned dispersion resin solution-1, 79 parts of carbon black #1000 (trade name, manufactured by Mitsubishi Chemical Corporation), 1.9 parts of 25% ammonia water, and 187 parts of ion-exchanged water were dispersed using a horizontal media disperser, DYNO-MILL Type KDL (trade name, manufactured by WAB Corporation). After dispersion, water was added, and coarse particles were removed by centrifugation to obtain the following pigment dispersion-1 with a pigment concentration of 14%. The non-volatile content (NV = solid content) of this pigment dispersion-1 was 17.5%. The commercially available carbon black #1000 used above had a particle diameter of 18 nm and a nitrogen adsorption specific surface area of ​​180 m 2 / g, pH 3.5. Pigment dispersion-1: 17.5% solids, 14% pigment concentration, black pigment (Mitsubishi Chemical Corporation, carbon black #1000)

[0059] <Preparation Examples 2-17> The following pigment dispersions-2 to-17 were prepared in the same manner as in Preparation Example 1, except that the types and amounts of pigment and dispersion resin solution and the amounts of ammonia water and ion-exchanged water were changed. Pigment dispersion-2: 19.4% solids, 15% pigment concentration, black pigment (Printex 80, manufactured by Orion Engineered Carbon), pigment dispersant (dispersion resin solution-2, as described above) Pigment dispersion-3: 19.5% solids, 15% pigment concentration, blue pigment (Dainichiseika Color & Chemicals Mfg. Co., Ltd., Chromofine Blue A-220JC), pigment dispersant (dispersion resin solution-2) Pigment dispersion-4: 32.8% solids, 24% pigment concentration, red pigment (Dainichiseika Color & Chemicals Mfg. Co., Ltd., SEIKAFAST RED 3522), pigment dispersant (Kao Corporation, Emulgen A-90 (nonionic surfactant)) Pigment dispersion-5: solids 52.8%, pigment concentration 50.3%, white pigment (Ishihara Sangyo Kaisha, Ltd., Typec CR-60), pigment dispersant (dispersion resin solution-3 mentioned above) Pigment dispersion-6: 30.3% solids, 30.0% pigment concentration, white pigment (Ishihara Sangyo Kaisha, Ltd., Typec CR-60), pigment dispersant (Toagosei Co., Ltd., Aron T-50 (acrylic acid-based dispersion resin solution)) Pigment dispersion-7: 30.9% solids, 30.0% pigment concentration, white pigment (Ishihara Sangyo Kaisha, Ltd., Typec CR-60), pigment dispersant (Toagosei Co., Ltd., Aron T-50 (acrylic acid-based dispersion resin solution)) Pigment Dispersion-8: 24.5% solids, 17.3% pigment concentration, white pigment (Ishihara Sangyo Kaisha, Ltd., Typec CR-60), pigment dispersant (Toagosei Co., Ltd., Aron T-50 (acrylic acid-based dispersion resin solution)) Pigment Dispersion-9: Solids 29.7%, pigment concentration 17.8%, white pigment (Ishihara Sangyo Kaisha, Ltd., Typec CR-60), pigment dispersant (Toagosei Co., Ltd., Aron T-50 (acrylic acid-based dispersion resin solution)) Pigment Dispersion-10: 38.1% solids, 16.2% pigment concentration, white pigment (Ishihara Sangyo Kaisha, Ltd., Typec CR-60), pigment dispersant (Toagosei Co., Ltd., Aron T-50 (acrylic acid-based dispersion resin solution)) Pigment Dispersion-11: 40.0% solids, 16.0% pigment concentration, white pigment (Ishihara Sangyo Kaisha, Ltd., Typec CR-60), pigment dispersant (Toagosei Co., Ltd., Aron T-50 (acrylic acid-based dispersion resin solution)) Pigment Dispersion-12: 40.5% solids, 15.0% pigment concentration, white pigment (Ishihara Sangyo Kaisha, Ltd., Typec CR-60), pigment dispersant (Toagosei Co., Ltd., Aron T-50 (acrylic acid-based dispersion resin solution)) Pigment Dispersion-13: 37.2% solids, 12.0% pigment concentration, white pigment (Ishihara Sangyo Kaisha, Ltd., Typec CR-60), pigment dispersant (Toagosei Co., Ltd., Aron T-50 (acrylic acid-based dispersion resin solution)) Pigment Dispersion-14: Solids 36.0%, pigment concentration 32.7%, black pigment (Mitsubishi Chemical Corporation, carbon black #44B), pigment dispersant (BASF Corporation, Tamol NN9401 (anionic surfactant)) Pigment Dispersion-15: 30.5% solids, 23.3% pigment concentration, black pigment (Mitsubishi Chemical Corporation, carbon black #970), pigment dispersant (Kao Corporation, Emulgen A-90 (nonionic surfactant)) Pigment Dispersion-16: 29.7% solids, 22.0% pigment concentration, black pigment (Mitsubishi Chemical Corporation, carbon black #44B), pigment dispersant (Sanyo Chemical Industries, Ltd., Levon 2000 (amphoteric surfactant)) Pigment Dispersion-17: 18.2% solids, 14.0% pigment concentration, black pigment (Mitsubishi Chemical Corporation, carbon black #44B), pigment dispersant (Arakawa Chemical Industries, Ltd., Arastar 703S (styrene-maleic acid-based dispersion resin solution))

[0060] Example 1 To a mixture of 18.9 parts of Pigment Dispersion-1 and 18.9 parts of Pigment Dispersion-2 obtained above, 29.74 parts of Boncoat NST-100EF (DIC Corporation) as a styrene-(meth)acrylic resin emulsion, 6 parts of 52 Additive (Dow Corning Toray Co., Ltd.) as a silicone resin emulsion, 1 part of BYK-348 (BYK Japan Co., Ltd.) as a surface conditioner, and 25.46 parts of water as a solvent were added to form an aqueous ink composition. This mixture was then dispersed using a dissolver to obtain an aqueous ink. Table 1 shows the composition of the resulting aqueous ink.

[0061] The following figures are also listed in Table 1. The content of pigment (A) relative to the total mass of the water-based ink (hereinafter also referred to as "pigment concentration") The solid content of the styrene-(meth)acrylic resin emulsion (E) relative to the total solid content of the water-based ink (hereinafter also referred to as "solid content of (E) / total solid content of ink") The solid content of the silicone resin emulsion (D) relative to the total solid mass of the water-based ink (hereinafter referred to as "solid content of (D) / total solid mass of ink") The mass ratio of the silicone resin emulsion (D) to the styrene-(meth)acrylic resin emulsion (E) in terms of solid content (hereinafter also referred to as "mass ratio (D) / (E))"). The mass ratio of the pigment dispersant (C) to the pigment (A) in terms of solid content (hereinafter also referred to as "mass ratio ((C) / (A))") The solid content of the surface conditioner (F) relative to the total solid mass of the water-based ink (hereinafter also referred to as "solid content of (F) / total solid mass of ink") The solid content of silicone resin emulsion (D) relative to the total mass of the water-based ink (hereinafter referred to as "solid content of (D) / total mass of ink") The solid content of the styrene-(meth)acrylic resin emulsion (E) relative to the total mass of the water-based ink (hereinafter also referred to as "solid content of (E) / total mass of ink") The solid content of the surface conditioner (F) relative to the total mass of the water-based ink (hereinafter also referred to as "solid content of (F) / total mass of ink")

[0062] <Examples 2 to 33 and Comparative Examples 1 to 10> For Examples 2 to 9, the water-based inks were obtained in the same manner as in Example 1, except that the materials were blended according to the compositions shown in Table 1. For Examples 10 to 18, the water-based inks were obtained in the same manner as in Example 1, except that the materials were blended according to the compositions shown in Table 2. For Comparative Examples 1 to 10, the water-based inks were obtained in the same manner as in Example 1, except that the materials were blended according to the compositions shown in Table 3. For Examples 19 to 26, the water-based inks were obtained in the same manner as in Example 1, except that the materials were blended according to the compositions shown in Table 4. For Examples 27 to 33, the water-based inks were obtained in the same manner as in Example 1, except that the materials were blended according to the compositions shown in Table 5. The raw materials used in each example are as follows:

[0063] [Raw materials used] Pigment Dispersion-1 to Pigment Dispersion-17 obtained in Preparation Examples 1 to 17 were used as pigment dispersions (mixtures of pigment (A), water (B), and pigment dispersant (C)).

[0064] The following compounds were used as the silicone resin emulsion (D). D-1:52 Additive (manufactured by Toray Dow Corning, solid content 65% by mass)

[0065] As the styrene-(meth)acrylic resin emulsion (E), the following compound was used. E-1: Ultrasol A-50 (manufactured by Aica Kogyo Co., Ltd., solid content 50% by mass, MFT: 5°C or less, Tg: 3°C) E-2: Boncoat NST-100EF (DIC Corporation, solid content 68% by mass, MFT: 13°C, Tg: 17°C) E-3: Yodosol AA76 (Henkel Japan, solid content 40%, MFT: 0°C, Tg: 37°C) E-4: Ultrasol KD-74 (manufactured by Aica Kogyo Co., Ltd., solid content 50% by mass, MFT: 35°C, Tg: 13°C)

[0066] As the surface conditioner (F), the following compounds were used. F-1: BYK-348 (manufactured by BYK Japan, solid content 96% by mass) F-2: BYK-3450 (BYK Japan, solids content 100%)

[0067] The following compounds were used as other components (anti-drying agent, film-forming agent, resin emulsion). Anti-drying agent: propylene glycol Film-forming agent: Solfit (Kuraray) Resin emulsion-1: Styrene-(meth)acrylic resin emulsion, AICA AIBO RAX-182 (manufactured by AICA Kogyo Co., Ltd., solid content 47.6% by mass, MFT: 42.5°C, Tg: 30°C) Resin emulsion-2: Polyurethane resin emulsion, Bayhydrol (registered trademark) UH2606 (manufactured by Covestro)

[0068] <<Evaluation of Water-Based Ink Compositions>> Using the aqueous ink composition of this embodiment, the aqueous ink composition was evaluated (line clarity, repelling, scratch resistance, water resistance, dishwasher resistance test, washing resistance test, and wet rub resistance test) by the following methods. The obtained results are shown in Tables 1 to 5. <Clarity of lines> For testing, a specified amount of each water-based ink of the Examples and Comparative Examples was filled into the core (filling) of a fiber bundle. The ink-filled filling was attached to a marker pen with a round tip. Using these pens, lines were drawn on paper. After drying, the image (drawn line) was used as an evaluation sample and the state of the image was evaluated. Specifically, the evaluation was based on the following criteria. (Evaluation criteria) 〇: The lines are clearly visible with no obvious blurring or unevenness and are thick enough ×: The lines are clearly blurred or uneven, or are too thin to be clearly visible.

[0069] <Repel> For testing, a specified amount of each water-based ink from each of the Examples and Comparative Examples was filled into the core (filling) of a fiber bundle. The ink-filled filling was attached to a marker pen with a round tip. Each pen was used to draw a line on a PP film, and after drying for 5 minutes, the state of the drawn line was observed. Specifically, the results were evaluated according to the following criteria. (Evaluation criteria) ◯: No repelling in the ink composition △: There is a slight amount of repelling in the ink composition, but it is not a problem in practical use. ×: The ink composition repels and writing is possible, but the drawn lines are not visible or writing is difficult

[0070] <Abrasion resistance test> For testing, a specified amount of each aqueous ink from the Examples and Comparative Examples was filled into a fiber bundle core (filling). The ink-filled filling was attached to a marker pen with a round tip. Using these pens, lines were drawn on substrates (PP film, PET film, metal plate, or glass plate), and the drawn lines were dried for 5 minutes. The dried images were used as evaluation samples to evaluate the abrasion resistance of the drawn lines. For the test, Kimwipes were wrapped around the index finger, and the abrasion resistance of the drawn lines was examined. Specifically, the index finger wrapped with Kimwipes was firmly pressed against the substrate, and the index finger was rubbed back and forth 30 times. The resulting scratches and peeling of the drawn lines were visually observed and evaluated. Specifically, the evaluation was based on the following criteria. 5: 0-5% deficiency 4: 6-15% deficiency 3: 16-35% loss 2:36-60% loss 1:61-100% defect

[0071] <Water resistance test> For testing, a specified amount of each aqueous ink from the Examples and Comparative Examples was filled into the core (batting) of a fiber bundle. The ink-filled batting was attached to a marker pen with a round tip. Using these pens, lines were drawn on a substrate (PP film or PET film), which was dried for 5 minutes and then immersed in tap water for 15 minutes. The immersed specimens were used as evaluation samples to evaluate the water resistance of the formed images (drawn lines). Specifically, a dish sponge was attached to the immersed substrate and rubbed back and forth 30 times, and the resulting scratches and peeling of the drawn lines were visually observed and evaluated. Specifically, evaluation was performed according to the following criteria. 5: 0-5% deficiency 4: 6-15% deficiency 3: 16-35% loss 2:36-60% loss 1:61-100% defect

[0072] <Dishwasher resistance test> For testing, a specified amount of each water-based ink from each example and comparative example was filled into the core (batting) of a fiber bundle. The ink-filled batting was attached to a marker pen with a round tip. Using these pens, lines were drawn on PP film or PET film, respectively. After drying for 5 minutes, the film was automatically washed, rinsed, and air-dried using the standard cycle in a dishwasher / dryer SS-M151 (product name, manufactured by Siroca Co., Ltd.). The standard cycle consisted of approximately 1 hour and 30 minutes of washing, rinsing, and air-drying, with hot water at approximately 65°C used only at the end of the rinse. No detergent was used during washing. After the standard cycle, the specimens were used as evaluation samples, and the resulting image (drawn line) was evaluated for its dishwasher resistance. Specifically, the evaluation criteria were as follows: (Evaluation criteria) 〇: No change in the lines is observed △: Visibility of drawn lines is reduced, but there is no practical problem ×: The drawn lines are discolored or come off, and visibility is clearly impaired.

[0073] <Washing durability test> For testing, a specified amount of each aqueous ink from the Examples and Comparative Examples was filled into the core (batting) of a fiber bundle. The ink-filled batting was attached to a marker pen with a round tip. Using these pens, lines were drawn on cotton cloth, which was dried for 5 minutes and then washed for 1 hour in a household washing machine at a water temperature of 40°C or 60°C. The test specimens were used as evaluation samples, and the formed images (drawn lines) were evaluated by visually judging the discoloration and fading grade in accordance with Clause 10 of JIS L 0801 (determination of color fastness). Specifically, the evaluation was based on the following criteria. (Evaluation criteria) 5:5th grade level 4:4th grade level 3: Level 3 2: Level 2 1:1st grade level

[0074] <Wet friction resistance test> For testing, a specified amount of each water-based ink from each example and comparative example was filled into the core (batting) of a fiber bundle. The ink-filled batting was attached to a marker pen with a round tip. Using these pens, lines were drawn on cotton fabric, and after drying for 5 minutes, the drawings from each example were evaluated according to the following criteria in accordance with the wet test specified in JIS L 0849, "Test method for color fastness to friction." The test was conducted using the Gakushin method. Evaluation was performed by visually judging the staining and discoloration grades in accordance with JIS L 0801, Clause 10 (Determination of color fastness), which is cited in JIS L 0849. (Evaluation criteria) 5:5th grade level 4:4th grade level 3: Level 3 2: Level 2 1:1st grade level

[0075] Further, dispersibility tests, storage stability tests, color development tests, and viscosity tests were carried out for Examples 19 to 26 by the following methods. The obtained results are shown in Table 4. <Dispersibility test> After preparing the pigment dispersions of Examples 19 to 26, the particle size distribution was measured using the following measuring device under the following conditions: Measuring device: SZ-100 (manufactured by Horiba, Ltd.), measuring principle: dynamic light scattering method, diluent: ion-exchanged water, measuring temperature: 25°C, and specifically, evaluation was performed according to the following criteria. (Evaluation criteria) 〇: Compared to before dispersion, the particle size distribution is sharper and the particles are uniformly finer △: The particles are slightly finer than before dispersion, but the particle size distribution is broad. ×: Particle size distribution has hardly changed compared to before dispersion

[0076] <Storage stability test> After preparing the pigment dispersions of Examples 19 to 26, they were left to stand at room temperature for one month, and the particle size distribution was measured in the same manner as in the dispersibility evaluation test described above. Specifically, the evaluation was made according to the following criteria. (Evaluation criteria) 〇: Particle size distribution remains the same compared to before standing △: A slight change in particle size distribution is observed compared to before standing ×: The particle size distribution has changed significantly compared to before standing.

[0077] <Color development test> A color-developed liquid was prepared using each of the pre-dispersion and post-dispersion solutions of the pigment dispersions of Examples 19 to 26, and comparative color-developing was performed, and the difference in density was visually observed. Specifically, the evaluation was based on the following criteria. (Evaluation criteria) 〇: The concentration has increased significantly compared to before dispersion △: The concentration has increased slightly compared to before dispersion ×: The concentration is almost the same or slightly higher than before dispersion

[0078] <Viscosity test> After preparing the pigment dispersions of Examples 19 to 26, the dispersions were transferred to a plastic cup, and immediately thereafter the viscosity of the liquid was visually confirmed. Specifically, the viscosity was evaluated according to the following criteria. (Evaluation criteria) 〇: The viscosity is very low, and when you tilt the plastic cup, the liquid flows like water. △: Medium viscosity, when the plastic cup is tilted, the liquid flows after a slight delay ×: The viscosity is high and the liquid does not move easily even when tilting the plastic cup.

[0079] [Table 1]

[0080] [Table 2]

[0081] [Table 3]

[0082] [Table 4]

[0083] [Table 5]

[0084] Furthermore, the fluorine-based surfactant Fluorad FC-430 (manufactured by 3M Japan) was used as the surface conditioner (F) instead of BYK-348 (manufactured by BYK Japan), and the evaluation was carried out in the same manner as in Example 1. The aqueous ink composition using Fluorad FC-430 (manufactured by 3M Japan) also showed excellent evaluation results, similar to those in Example 1.

[0085] For reference, the same dishwasher resistance test as above was carried out on various commercially available oil-based writing pens, and they were evaluated in the same manner and compared with the pens of the examples of the present invention.

[0086] (Reference example 1) A commercially available oil-based, cotton-filled pen, Mackie (registered trademark, manufactured by Zebra), was used to draw lines on PP film and PET film, and a dishwasher resistance test was conducted and evaluated in the same manner as in Examples. As a result, the commercially available water-based pen of Reference Example 1 faded under all conditions.

[0087] As application examples, the aqueous ink composition according to this embodiment was used in a direct ink marker pen, a spray coating agent, a stamp ink, or a ballpoint pen, and the various evaluation tests described above were carried out to evaluate the aqueous ink composition.

[0088] (Application example 1) Direct ink marker pen Direct-fill marker pens, in which the ink is filled directly into the pen body, were filled with the water-based inks of Example 4 and Comparative Example 5. Lines were drawn on PP film and PET film using the marker pens and allowed to dry for 5 minutes. These were used as evaluation samples, and the lines drawn by the marker pen filled with the water-based ink used in Example 4 achieved particularly excellent results in the abrasion resistance, water resistance, and wet rub resistance tests on PP film and PET film, thereby achieving the object of the present invention. On the other hand, the lines drawn by the marker pen filled with the water-based ink used in Comparative Example 5 achieved poor results in the abrasion resistance, water resistance, and wet rub resistance tests on PP film and PET film, failing to achieve the object of the present invention.

[0089] (Application Example 2) Spray coating agent The water-based ink of Example 2 was loaded into a small spray gun "W-71-2G" (manufactured by Anest Iwata Corporation), and the water-based coating agent was applied to plastic molded products (PP blocks, PET blocks) by spray coating, and then dried at about 60°C for several minutes to form a coating film. When this was evaluated as an evaluation sample, it showed particularly excellent results in the abrasion resistance test, water resistance test, and dishwasher resistance test, and the object of the present invention was achieved.

[0090] (Application example 3) Stamp ink The water-based ink of Example 4 was applied to a commercially available ink pad, a medium-sized ink pad for application (manufactured by Shachihata Co., Ltd.). A rubber stamp with the ink applied to this ink pad was used to print on a PP film, and an abrasion resistance test was conducted. The abrasion resistance was evaluated, and the results were significantly superior to that of a PP film printed with a commercially available oil-based pigment ink pad.

[0091] (Application Example 4) Ballpoint pen The aqueous ink of Example 14 was filled into a ballpoint pen refill, and a ballpoint pen equipped with the refill was obtained. A line was drawn on a PP film using this pen and a commercially available aqueous ballpoint pen, Sarasa (registered trademark, manufactured by Zebra Corporation), and the film was allowed to dry for 5 minutes. A comparison of the resulting handwriting revealed that the ballpoint pen of this embodiment had particularly superior line clarity. Furthermore, when this evaluation sample was evaluated in a scratch resistance test, excellent results were obtained, demonstrating the achievement of the objective of the present invention.

[0092] As application examples, flexographic ink, gravure ink, or inkjet ink was prepared using the aqueous ink composition according to this embodiment, and the various evaluation tests described above were carried out using these aqueous inks to evaluate the aqueous ink composition.

[0093] (Application example 5) Flexographic ink 100 parts of the water-based ink obtained in Example 2, 2.4 parts of "Denacol EX-612" (solids content), 0.08 parts of thickener (solids content), 0.04 parts of antifoaming agent (solids content), and 0.2 parts of surfactant were added and mixed thoroughly using a disperser. The mixture was then diluted with water to a temperature of 16 seconds (25°C) in a Zahn cup #4 (manufactured by Rigo Co., Ltd.) to obtain a black water-based flexographic ink. A uniaxially shrinkable PET film (Toyobo Space Clean S7053, Toyobo Co., Ltd., thickness 40 μm) was applied to a plastic film (uniaxially shrinkable PET film, product name: Toyobo Space Clean S7053, Toyobo Co., Ltd., thickness 40 μm) with a cell volume of 6.0 cm. 3 / m 2 A flexo hand proofer equipped with an anilox roll was used as the applicator, and the coating weight after drying was 1.0 g / m. 2The black ink prepared so as to obtain a black ink having a thickness of approximately 0.85 μm was applied to a plastic film. After application, the film was dried at 25°C for 72 hours to obtain a printed matter in which a printed layer, a dry film having a thickness of approximately 0.85 μm, was formed on one side of the plastic film. Various evaluation tests were carried out using the printed matter, and it was found that the printed matter had excellent abrasion resistance and water resistance.

[0094] (Application example 6) Gravure ink 372 parts of the water-based ink obtained in Example 2 were mixed with 580 parts of IRR-11, 31 parts of ion-exchanged water, 4 parts of a surfactant (trade name "Tegowet 500", manufactured by Evonik), 8 parts of a thickener (trade name "SN Thickener 623N", manufactured by San Nopco), and 2 parts of an antifoaming agent. The mixture was diluted with ion-exchanged water so that the viscosity measured with Zahn cup #4 was 14 seconds at 25°C, to obtain a water-based gravure ink for coating. <Production of printed materials> Anilox roll (cell volume: 4.5cm 3 / m 2 Using a flexographic hand proofer equipped with a flexographic printer as an applicator, the water-based gravure ink was applied to a plastic film (uniaxially shrinkable PET film, product name "Toyobo Space Clean S7053", manufactured by Toyobo Co., Ltd., thickness 40 μm). The ink was then dried at 25°C for 48 hours to form a coating film on the substrate film, yielding a print for testing. Various evaluation tests were carried out using the print, and it was found that the print had excellent abrasion resistance and water resistance.

[0095] (Application Example 7) Inkjet ink The aqueous ink obtained in Example 2 was filtered through a 5 μm membrane filter to obtain an inkjet ink. This ink was filled into an ink cartridge, and vertical and horizontal straight lines were printed using an inkjet printer on inkjet glossy paper Photolike QP (manufactured by Konica Corporation). The degree of print distortion was visually observed, and no distortion was found. In particular, to evaluate the abrasion resistance of glossy paper, the printed surface was rubbed with a finger to check for any loss of gloss. No peeling was observed, indicating a good result.

Claims

1. A pigment (A), Water (B), a pigment dispersant (C); a silicone resin emulsion (D); a styrene-(meth)acrylic resin emulsion (E); An aqueous ink composition comprising: the styrene-(meth)acrylic resin emulsion (E) has a minimum film-forming temperature of 0°C or higher and 35°C or lower; the solid content of the styrene-(meth)acrylic resin emulsion (E) is 15% by mass or more and 67% by mass or less, based on the total mass of the solid contents of the aqueous ink composition; the mass ratio ((D) / (E)) of the silicone resin emulsion (D) to the styrene-(meth)acrylic resin emulsion (E) in terms of solid content is 0.1 or more and 1.8 or less; Aqueous ink compositions.

2. the solid content of the silicone resin emulsion (D) is 1% by mass or more and 13% by mass or less relative to the total mass of the aqueous ink composition; the solid content of the styrene-(meth)acrylic resin emulsion (E) is 3% by mass or more and 30% by mass or less relative to the total mass of the aqueous ink composition; The aqueous ink composition according to claim 1.

3. the solid content of the silicone resin emulsion (D) is 13% by mass or more and 30% by mass or less, based on the total mass of the solid contents of the aqueous ink composition; The aqueous ink composition according to claim 1.

4. The glass transition temperature of the styrene-(meth)acrylic resin emulsion (E) is 0°C or higher and 40°C or lower. The aqueous ink composition according to claim 1.

5. the pigment dispersant (C) contains at least one selected from the group consisting of a dispersion resin made of a forming material containing at least one of a styrene-based monomer and a (meth)acrylic acid-based monomer, an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant; a mass ratio ((C) / (A)) of the pigment dispersant (C) to the pigment (A) in terms of solid content is 0.02 or more and 1.9 or less; The aqueous ink composition according to claim 1.

6. Further, a surface conditioner (F) is contained, the surface conditioner (F) is a surfactant, the solid content of the surface conditioner (F) is 0% by mass or more and 30% by mass or less relative to the total mass of the solid contents of the aqueous ink composition; The aqueous ink composition according to claim 1.

7. The surface conditioner (F) contains at least one of a fluorine-based surfactant and a polyether-modified siloxane-based surfactant. The aqueous ink composition according to claim 6.

8. Further, it contains an anti-drying agent, The aqueous ink composition according to claim 1.

9. Further, a film-forming agent is contained, The aqueous ink composition according to claim 1.

10. The aqueous ink composition according to any one of claims 1 to 9, Water-based ink.

11. It is used for at least one application selected from any one of flexographic ink, gravure ink, and inkjet ink. The water-based ink according to claim 10.

12. 11. Use of the water-based ink according to claim 10 in any one of a swath pen, a direct ink pen, a spray coating, a stamp ink, and a ballpoint pen.

13. A coated product using the water-based ink according to claim 10.

14. A coated product obtained by using any one of the coating materials according to claim 12.

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