JP2016147984A - Inkjet ink set, inkjet recording method, inkjet recorded matter and inkjet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet ink set capable of exhibiting excellent drying property even when printed on a non-porous base material, and imparting high glossiness, scratch resistance, ethanol resistance and bleeding resistance to a printed part.SOLUTION: An inkjet ink set is used at an inkjet recording system. The ink set at least includes: a yellow ink, a cyan ink, a magenta ink and a black ink. Each ink at least includes water, organic solvent, pigment-containing polymer particles, polycarbonate modified urethane resin particles and surfactant. The average particle diameter of the pigment-containing polymer particles in the yellow ink (D50) is 1.5-5.0 times larger than the average particle diameter of the pigment-containing polymer particles in any of other three inks.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inkjet ink set, an inkjet recording method, an inkjet recording, and an inkjet recording apparatus.

  Inkjet printers have advantages such as low noise, low running cost, and easy color printing, and thus are widely used as digital signal output devices in general households. In recent years, inkjet technology has been used not only for such home use but also for industrial use such as a display, a poster, and a bulletin board.

In such applications, non-porous substrates such as plastic films are used because porous substrates have problems with durability such as light resistance, water resistance, and abrasion resistance. Inks have been developed.
As such an ink, for example, a solvent-based inkjet ink using an organic solvent as a vehicle and an ultraviolet curable inkjet ink mainly composed of a polymerizable monomer have been widely used.

  However, recently, an inkjet ink that can be directly printed on a non-porous substrate has been developed with a water-based inkjet recording ink that has a low environmental impact and has been widely used as a household inkjet ink.

  However, in general, these water-based inks are liable to cause poor drying and have a poor gloss as compared with solvent-based inkjet inks. Furthermore, regarding image fastness, sufficient properties have not been obtained with respect to scratch resistance, ethanol resistance, and light resistance, and it has been pointed out that the image quality is inferior.

  In particular, the water-based ink has a problem that an image tends to be blurred due to poor quick drying. In particular, when it is necessary to perform printing on a non-porous substrate at high speed, it is necessary to eject a large amount of ink at a time. ing. (For example, see Patent Document 1)

  In Patent Documents 2 and 3, from the viewpoint of color reproducibility, in an ink set containing cyan ink, yellow ink, and magenta ink, the dispersion average particle diameter of water-insoluble colorant particles contained in the yellow ink is 60 to 200 nm. An ink set is disclosed in which the water-insoluble colorant particles contained in at least one of the inks different from the yellow ink have a dispersion average particle diameter of 5 to 50 nm.

  The present invention provides an ink jet ink set that exhibits good drying properties even when printed on a non-porous substrate, and has a high gloss, scratch resistance, ethanol resistance, light resistance, and bleeding resistance on the printed portion. The purpose is to provide.

As a result of intensive studies, the present inventors have
An inkjet ink set used for an inkjet recording method, wherein the ink set is composed of at least a yellow ink, a cyan ink, a magenta ink, and a black ink, and each of the inks includes at least water, an organic solvent, and pigment-containing polymer particles. The average particle size (D50) of the pigment-containing polymer particles in the yellow ink is greater than the average particle size of the pigment-containing polymer particles in all other three inks. The present inventors have found that the above problems can be solved when using an inkjet ink set characterized by being 1.5 to 5.0 times larger, and have reached the present invention.

  According to the present invention, an ink set that exhibits good drying properties even when printed on a non-porous substrate and has a high gloss, scratch resistance, ethanol resistance, light resistance, and bleeding resistance on the printed portion. Can be provided.

1 is a schematic diagram illustrating a configuration in an embodiment of an ink jet recording apparatus according to the present invention. It is the schematic which shows the internal structure of the apparatus main body of the inkjet recording device shown in FIG.

  An ink jet ink set (hereinafter simply referred to as “ink”) set according to the present invention is an ink jet ink set used in an ink jet recording method, and the ink set includes at least yellow ink, cyan ink, magenta ink, and Each ink is composed of a black ink, and each ink contains at least water, an organic solvent, pigment-containing polymer particles, polycarbonate-modified urethane resin particles, and a surfactant. The average particle diameter of the pigment-containing polymer particles in the yellow ink ( D50) is 1.5 to 5.0 times larger than the average particle size of the pigment-containing polymer particles in all the other three colors of ink.

Hereinafter, the ink set for ink jet, the ink jet recording method, the ink jet recorded matter, and the ink jet recording apparatus according to the present invention will be described.
Although the embodiments described below are preferred embodiments of the present invention, various technically preferable limitations are applied, but the scope of the present invention is limited to the following description. Unless otherwise described, the present invention is not limited to these embodiments.

  Since the organic solvent added to the ink generally has a boiling point higher than that of water and is difficult to dry, it is necessary to add an organic solvent having a relatively low boiling point in order to obtain drying properties. However, when quick drying is required, the resin film formation is generally too fast, so that a sufficiently uniform coating film cannot be formed, resulting in poor film strength and glossiness.

  As a result of continuing to study the relationship between the existing resin and the organic solvent, the present inventors have found that a uniform film can be formed by using the polycarbonate-modified urethane resin and the organic solvent.

  In particular, the polycarbonate-modified urethane resin is excellent in water resistance, heat resistance, abrasion resistance, and weather resistance due to the high cohesive strength of the carbonate group, and is suitable for printed matter used in harsh environments such as outdoor applications. As a result, after the organic solvent is printed as ink together with the polycarbonate-modified urethane resin emulsion particles, it promotes moderate drying and fusion between the resin emulsions, thereby enabling uniform film formation and high gloss on the printed part. In addition, it is possible to exhibit scratch resistance and ethanol resistance. In addition, from the viewpoint of the bleeding resistance desired in the present invention, it is preferable because the flow to the yellow image of another color is suppressed at the color boundary portion immediately after printing for the reason described above. Moreover, when the organic solvent whose boiling point exceeds 250 degreeC is not included, dryability can further be improved.

  The pigment is present in the ink in the form of pigment-containing polymer particles, and the average particle diameter (D50) of the pigment-containing polymer particles in the yellow ink is the average particle size of the pigment-containing polymer particles in all three other colors of ink. By being 1.5 to 5.0 times larger than the diameter, it became possible to ensure the bleeding resistance to the non-porous substrate.

  Next, other components of the ink of the present invention will be described. The ink component of the present invention contains at least water, an organic solvent, pigment-containing polymer particles, polycarbonate-modified urethane resin particles, a surfactant, and an antiseptic / antifungal agent, a rust inhibitor, a pH adjuster and the like as necessary. May be included.

(Polycarbonate-modified urethane resin particles)
First, the polycarbonate-modified urethane resin particles used in the present invention will be described. The polycarbonate-modified urethane resin in the present invention refers to one obtained by reacting polycarbonate polyol and polyisocyanate.

  As said polycarbonate polyol, what is obtained by transesterifying a carbonate ester and a polyol in presence of a catalyst, for example, and the thing obtained by making phosgene and bisphenol A react can be used.

  As the carbonate ester, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used.

  Examples of the polyol to be reacted with the carbonate ester include ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5-pentane. Low molecular diol compounds such as diol, neopentyl glycol, 1,4-cyclohexanediol, 1,6-hexanediol, polyethylene glycol, polypropylene glycol, and the like can be used.

  The polyisocyanate that can be used in the present invention can be used without particular limitation. For example, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6- Tolylene diisocyanate, 4,4'-diphenylenemethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl Aromatic polyisocyanate compounds such as 3,3′-dimethyl-4,4′-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate; Tylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl carbonate Aliphatic polyisocyanate compounds such as proate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate; isophorone diisocyanate ( IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated) Alicyclic polycyanate compounds such as TDI), bis (2-isocyanatoethyl) -4-dichlorohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate, etc. These may be used alone or in combination of two or more.

  Since the ink in the present invention is also used for outdoor applications such as posters and signboards, it requires a coating film having a very high long-term weather resistance, and from this viewpoint, an aliphatic or alicyclic diisocyanate should be used. Is preferred. Furthermore, in the present invention, it is preferable to add at least one alicyclic diisocyanate, which makes it easy to obtain the desired coating strength.

  Among these, isophorone diisocyanate and dicyclohexylmethane diisocyanate can be particularly preferably used, and the ratio of the alicyclic diisocyanate is preferably 60% by mass or more in the total isocyanate compound.

  In the present invention, the polycarbonate-modified urethane resin particles may be added in the form of a resin emulsion dispersed in an aqueous medium. In that case, the resin solid content in the resin emulsion is preferably 20% by mass or more, and if it is 20% by mass or more, it is preferable because the prescription design for making an ink is easy.

  The urethane resin particles at this time desirably have an average particle size in the range of 10 to 350 nm from the viewpoint of liquid storage stability and ejection stability when converted into ink.

  In addition, when dispersing urethane resin particles in an aqueous medium, a forced emulsification type using a dispersant can be used. However, the dispersant remains in the coating film and may reduce the strength. A so-called self-emulsifying type having an anionic property can be suitably used. In that case, it is preferable to contain an anionic group in an acid value range of 20 to 100 in order to impart excellent scratch resistance and chemical resistance.

  In addition, as the anionic group, a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group, and the like can be used, and among them, a carboxylate group or a sulfonate partially or completely neutralized with a basic compound or the like. It is preferable to use a group for maintaining good water dispersion stability.

  Examples of basic compounds that can be used for neutralizing the anionic group include organic amines such as ammonia, triethylamine, pyridine, morpholine, alkanolamines such as monoethanolamine, Na, K, Li, and Ca. And metal base compounds.

  When the forced emulsification method is used, as the surfactant, any of a nonionic surfactant and an anionic surfactant can be used. However, the nonionic surfactant is preferable because it has better water resistance.

  Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkylene alkyl ether, polyoxyethylene derivative, polyoxyethylene fatty acid ester, polyoxyethylene polyhydric alcohol fatty acid ester, polyoxyethylene propylene polyol, sorbitan fatty acid ester , Polyoxyethylene hydrogenated castor oil, polyoxyalkylene polycyclic phenyl ether, polyoxyethylene alkylamine, alkylalkanolamide, polyalkylene glycol (meth) acrylate and the like. Preferably, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine and the like can be mentioned.

  As an anionic surfactant, alkyl sulfate ester salt, polyoxyethylene alkyl ether sulfate, alkylbenzene sulfonate, α-olefin sulfonate, methyl taurate, sulfosuccinate, ether sulfonate, ether carboxylate, Fatty acid salts, naphthalenesulfonic acid formalin condensates, alkylamine salts, quaternary ammonium salts, alkylbetaines, alkylamine oxides and the like are preferable, and polyoxyethylene alkyl ether sulfates, sulfosuccinates and the like are preferable.

  0.1-30 mass% is preferable with respect to urethane resin, and, as for the addition amount of surfactant, More preferably, it is 5-20 mass%. If it exceeds 30% by mass, the excess emulsifier more than necessary to form a urethane resin emulsion will significantly reduce the adhesion and water resistance. This is not preferable because it is likely to cause blocking.

  In addition, the urethane resin emulsion in the present invention may contain other water-soluble organic solvents, preservatives, leveling agents, antioxidants, light stabilizers, ultraviolet absorbers, and the like as necessary.

Next, the manufacturing method of the polycarbonate modified urethane resin particle in this invention is demonstrated. As the production method, any of the methods generally used in the past can be used, and examples thereof include the following methods.
First, in the absence of a solvent or in the presence of an organic solvent, the polycarbonate polyol and the polyisocyanate are reacted at an equivalent ratio in which an isocyanate group becomes excessive to produce an isocyanate-terminated urethane prepolymer.
Next, the anionic group in the isocyanate-terminated urethane prepolymer is neutralized with the neutralizing agent as necessary, and then reacted with a chain extender, and finally the organic solvent in the system is removed as necessary. Can be obtained.

  In this case, usable organic solvents include, for example, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, acetates such as ethyl acetate and butyl acetate, nitriles such as acetonitrile, dimethylformamide, N- Examples include amides such as methylpyrrolidone and 1-ethyl-2-pyrrolidone, and these may be used alone or in combination of two or more.

  As the chain extender, polyamines and other active hydrogen atom-containing compounds can be used.

  Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 1,4-cyclohexane. Diamines such as diamine and 2-methyl-1,5-pentanediamine, polyamines such as diethylenetriamine, dipropylenetriamine and triethylenetetramine, hydrazine, N, N′-dimethylhydrazine, 1,6-hexamethylenebishydrazine and the like Hydrazines, succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, and the like can be used.

  Examples of the other active hydrogen-containing compounds include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, saccharose, Glycols such as methylene glycol, glycerin, sorbitol, bisphenol A, 4,4′-dihydroxydiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, phenols such as hydroquinone, In addition, water and the like can be used alone or in combination of two or more within a range in which the storage stability of the coating agent does not decrease.

  The ink of the present invention can be used satisfactorily because the residual solvent is reduced by performing heat treatment, the adhesiveness is improved, and the polycarbonate-modified urethane resin particles have high heat resistance.

  The polycarbonate-modified urethane resin particles used in the present invention do not necessarily have to have a minimum film-forming temperature of room temperature or lower. However, when heating, the minimum film-forming temperature is preferably at least the temperature to be heated or lower.

  The minimum film-forming temperature of the polycarbonate-modified urethane resin emulsion comprising polycarbonate-modified urethane resin particles contained in water or water and a solvent is preferably 0 ° C. or more and lower than the heating temperature by 5 ° C. or more. The temperature is preferably 25 ° C or higher and lower than the heating temperature by 10 ° C or higher.

In general, the lower the film-forming temperature is, the better the film-forming property is. However, when the minimum film-forming temperature is too low, the glass transition point of the resin is low and sufficient film strength cannot be obtained.
The minimum film-forming temperature is the lowest temperature at which a transparent continuous film is formed when a polycarbonate-modified urethane resin emulsion is cast thinly on a metal plate such as aluminum and the temperature is raised. Point to. In the temperature range below the minimum film-forming temperature, the polycarbonate-modified urethane resin emulsion is in a liquid state or a white powder.

In addition, the polycarbonate-modified urethane resin used in the present invention preferably has a surface hardness of 100 N / mm ² or more, and when satisfying this, the ink of the present invention forms a tough coating film and has a higher scratch resistance. Can be obtained.

  The surface hardness in the present invention can be measured, for example, by the following method. The polycarbonate-modified urethane resin emulsion is applied on a slide glass so as to have a film thickness of 10 μm, and then dried at 100 ° C. for 30 minutes. About the formed resin film, using a micro surface hardness tester (FISCHERSCOPE HM2000, manufactured by Fischer), the indentation depth when the Barkovic indenter was indented with a load of 9.8 mN was obtained, and the Martens hardness described in ISO14577-2002 was obtained. It can be measured.

  In the ink of the present invention, the polycarbonate-modified urethane resin particles are preferably added in an amount of 0.5 to 10% by mass in terms of solid content in the ink, more preferably 1 to 8% by mass, and even more preferably 3 to 3% by mass. 8% by mass. By setting it within this range, image fastness and ejection stability are particularly excellent and preferable.

  The ink of the present invention may contain a resin other than the polycarbonate-modified urethane resin particles, but 50% by mass or more of the resin added to the ink in order to sufficiently satisfy the effects of the invention is preferably a polycarbonate-modified urethane resin. More preferably, 70% by mass or more is polycarbonate-modified urethane resin.

  Examples of resin particles that can be contained in addition to the polycarbonate-modified urethane resin particles include acrylic resin particles, polyolefin resin particles, vinyl acetate resin particles, vinyl chloride resin particles, fluororesin particles, polyether resin particles, and polyester resin particles. Is mentioned.

(Pigment-containing polymer particles)
Next, the pigment used in the present invention will be described. In the present invention, recording inks containing pigments such as cyan, magenta, yellow, and black can be used.

In particular, since the average particle diameter (D50) of the pigment-containing polymer particles in the yellow ink is 1.5 to 5.0 times larger than the average particle diameter of the pigment-containing polymer particles in all the other three colors of ink, non-porous It becomes possible to ensure the bleeding resistance to the quality base material. The reason is not clear, but I guess as follows. Generally, the smaller the average particle size of the pigment-containing polymer particles, the more difficult it is to ensure dispersion stability. The pigment tends to aggregate at high temperatures during heat drying, but the average particle size of the pigment-containing polymer particles in the yellow ink Is larger than the other three colors, the dispersion stability of the yellow pigment is ensured even at high temperatures, and the fluidity of the yellow ink during heat drying tends to be slower than the other colors. As a result, the flow to the yellow image of another color is suppressed at the color boundary portion immediately after printing, thereby ensuring the bleeding resistance. The so-called color bleed is known to be most noticeable in a yellow image in the ink set, and the above behavior of the yellow ink is superior in suppressing color bleed.
The average particle diameter (D50) of the pigment-containing polymer particles in the yellow ink is preferably 1.5 to 4.0 times larger than the average particle diameter of the pigment-containing polymer particles in all the other three colors of ink.

The average particle diameter (D50) of the pigment-containing polymer particles is preferably 0.01 to 0.25 μm in the ink. By setting it within this range, image fastness, ejection stability and image quality are particularly excellent and preferable. For the yellow pigment, the average particle diameter (D50) of the pigment-containing polymer particles is preferably 0.10 to 0.25 μm for the reasons described above.
In addition, an average particle diameter (D50) can be obtained as a value based on a dynamic light scattering method using a particle size distribution measuring device (Nikkiso Co., Ltd., Nanotrac UPA-EX150). D50 is a value accurately obtained as a median diameter, and indicates a diameter in which the integrated values of the particle size distribution on the large side and the small side are equal when the powder is divided into two from a certain particle size. .

  Examples of the color of the pigment include those for black and color. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the black material include carbon black produced by a known production method such as a channel method, an oil furnace method, a furnace method, an acetylene black method, or a thermal black method.

  For the color ink, for yellow ink, for example, C.I. I. Pigment Yellow 1 (Fast Yellow G), 3, 12 (Disazo Yellow AAA), 13, 14, 17, 23, 24, 34, 35, 37, 42 (Yellow Iron Oxide), 53, 55, 74, 81, 83 (Disazo Yellow HR), 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 138, 150, 153, 155 and the like.

  For magenta ink, for example, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48: 2 (Permanent Red 2B (Ba)), 48: 2 (Permanent Red 2B (Ca)), 48 : 3 (Permanent Red 2B (Sr)), 48: 4 (Permanent Red 2B (Mn)), 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81 (Rhodamine 6G Lake), 83, 88, 92, 101 (Bengara), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (Dimethylquinacridone), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 2 9, and the like.

  For cyan, for example, C.I. I. Pigment Blue 1, 2, 15 (copper phthalocyanine blue R), 15: 1, 15: 2, 15: 3 (phthalocyanine blue G), 15: 4, 15: 6 (phthalocyanine blue E), 16, 17: 1, 56, 60, 63 and the like.

  Examples of intermediate colors include C.I. I. Pigment red 177, 194, 224, C.I. I. Pigment orange 43, C.I. I. Pigment violet 3, 19, 23, 37, C.I. I. Pigment green 7, 36, and the like.

  The amount of the pigment added as the coloring material in the ink composition is preferably about 0.1 to 10% by mass, more preferably about 1 to 10% by mass. In general, when the pigment concentration is increased, the image density is increased and the image quality is improved. However, the reliability such as fixing property, ejection stability, and clogging tends to be adversely affected.

The “pigment-containing” of the pigment-containing polymer particles means either or both of a state where the pigment is encapsulated in the polymer particles and a state where the pigment is adsorbed on the surface of the polymer particles. In this case, it is not necessary for all the pigments blended in the ink of the present invention to be encapsulated or adsorbed in the polymer particles, and even if the pigment is dispersed in the dispersion medium as long as the effects of the present invention are not impaired. Good. The pigment is not particularly limited as long as it is a water-insoluble or hardly water-soluble pigment and can be adsorbed by the polymer, and can be appropriately selected according to the purpose.
Here, the “water-insoluble or poorly water-soluble” means that the amount of the coloring material dissolved at 25 ° C. with respect to 100 parts by mass of water is 10 parts by mass or less, preferably 5 parts by mass or less, more preferably 1 part by mass or less. Means that. Further, “dissolve” means that separation or sedimentation of the coloring material is not observed in the surface layer or the lower layer of the aqueous solution visually.

  Examples of the polymer that forms the polymer particles (polymer in the polymer particles) include vinyl polymers, polyester polymers, polyurethane polymers, and the like. Particularly preferred are vinyl polymers and polyester polymers. Polymers disclosed in JP-A-53897 and JP-A-2001-139849 can be used.

The pigment-containing polymer particles can be produced by a known method. For example, the method described in many literatures, such as Unexamined-Japanese-Patent No. 2001-187851, is used.
The average particle diameter (D50) of the pigment-containing polymer particles is such that particles having a desired average particle diameter can be obtained depending on the dispersion conditions when the pigment-containing polymer particles are produced. Furthermore, it is governed by the number of kneading operations such as a roll mill in the dispersion treatment.

(Organic solvent)
In the present invention, an organic solvent is included in the ink. Although it does not specifically limit as an organic solvent, A water-soluble organic solvent is used suitably.
Examples of water-soluble organic solvents that can be used in the present invention include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 2,3. -Butanediol, 1,4-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 1,6-hexanediol, glycerin, 1, Polyhydric alcohols such as 2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl 1,2,4-butanetriol, 1,2,3-butanetriol, petriol, ethylene glycol monoethyl Ether, ethylene glycol monobutyl ether, polyethylene Polyhydric alcohol alkyl ethers such as glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, polyhydric alcohol aryl such as ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether Ethers, nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone, formamide, Amides such as N-methylformamide, N, N-dimethylformamide, monoethanolamine, diethanolamine, triethylamine, etc. Min include dimethyl sulfoxide, sulfolane, sulfur-containing compounds such as thiodiethanol, propylene carbonate, although ethylene carbonate and the like, it is preferable that a boiling point of 250 ° C. or less.

  The organic solvent contained in the ink of the present invention consists only of an organic solvent having a boiling point of 250 ° C. or less, and preferably has a boiling point of less than 220 ° C., from the viewpoints of drying properties and glossiness.

  Among these, it contains at least one selected from the group consisting of 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol and 2,3-butanediol. It is preferable. When these are used, an ink having good compatibility with the polycarbonate-modified urethane resin can be obtained, and more excellent film forming property can be obtained, and high gloss is easily obtained.

  The total amount of the organic solvent contained in the entire ink is preferably in the range of 20 to 70% by mass, and more preferably in the range of 30 to 60% by mass. By setting it within this range, discharge stability is particularly excellent and preferable.

(water)
There is no restriction | limiting in particular as water used for this invention, For example, pure water, such as ion-exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used. There is no restriction | limiting in particular in water content in the ink for inkjet recording, According to the objective, it can select suitably.

(Surfactant)
In the ink of the present invention, a surfactant is added for the purpose of ensuring wettability to media. In particular, the surfactant content in the yellow ink is preferably greater than the surfactant content in the other inks. As a result, wetting and spreading of dots during printing is slower than that of yellow ink in other colors, and when yellow and other colors come into contact with each other, erosion of yellow images of other colors is suppressed, so that more resistance to bleeding is secured. Can do. The ratio of the content ratio (A) based on the weight basis of the surfactant in the yellow ink to the content ratio (B) based on the weight basis of the surfactant in the other ink is (B) / (A) = 1. A range of 0.0 / 1.3 to 1.0 / 3.0 is more preferable in ensuring bleeding resistance. The addition amount of the surfactant is preferably 0.1% by mass to 5% by mass as an active ingredient in the ink from the viewpoint of image quality and ejection stability.

If the said restrictions are satisfy | filled, the surfactant to be used can be used without limitation.
As the surfactant, any of amphoteric surfactants, nonionic surfactants, and anionic surfactants can be used. However, polyoxyethylene alkylphenyl is used because of the dispersion stability of the coloring material and the image quality. Nonionic series such as ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, ethylene oxide adduct of acetylene alcohol A surfactant is desirably used. Depending on the formulation, it is possible to use (or use alone) a fluorine-based surfactant or a silicone-based surfactant.

(Other additives)
Examples of other additives include ultraviolet absorbers, antiseptic / antifungal agents, rust preventives, pH adjusters and the like.
Next, the ultraviolet absorbent used in the present invention will be described. Ultraviolet absorbers are added to improve image fastness, particularly light resistance. The ultraviolet absorber is not particularly limited. For example, a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, a salicylate ultraviolet absorber, a cyanoacrylate ultraviolet absorber, a nickel complex salt ultraviolet absorber, or an oxalic acid anilide type. It can be appropriately selected from ultraviolet absorbers, triazine-based ultraviolet absorbers and the like. Details are illustrated below.

  Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2,4-dihydroxybenzophenone, and 2-hydroxy-4-methoxybenzophenone. 2,2 ′, 4,4′-tetrahydroxybenzophenone, and the like.

  Examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-4′-octoxyphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, and the like.

  Examples of the salicylate-based ultraviolet absorber include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, and the like.

  Examples of the cyanoacrylate ultraviolet absorber include ethyl-2-cyano-3,3′-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate, and butyl-2- And cyano-3-methyl-3- (p-methoxyphenyl) acrylate.

  Examples of the nickel complex-based ultraviolet absorber include nickel bis (octylphenyl) sulfide, 2,2′-thiobis (4-tert-octylferrate) -n-butylamine nickel (II), and 2,2′-thiobis. (4-tert-octyl ferrate) -2-ethylhexylamine nickel (II), 2,2′-thiobis (4-tert-octyl ferrate) triethanolamine nickel (II), and the like.

A commercial item can be used as said triazine type ultraviolet absorber. Specific examples include TUNIVIN 400-DW, TUNIVIN 477-DW, TUNIVIN 479-DW (manufactured by BASF).
An ultraviolet absorber may be used independently or may use 2 or more types together.

  The content of the ultraviolet absorber is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass as an active ingredient in the ink. If it is 0.5 mass% or more, a sufficient addition effect can be obtained. Moreover, if it is 20 mass% or less, a crystal | crystallization does not precipitate when an ink dries (a nozzle periphery).

Antiseptic and antifungal agents As antiseptic and antifungal agents, 1,2-benzisothiazolin-3-one, sodium benzoate, sodium dehydroacetate, sodium sorbate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, etc. Is mentioned.
Antirust agent Examples of the antirust agent include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.
pH adjuster As the pH adjuster, any substance can be used as long as it can adjust the pH to a desired value without adversely affecting the ink to be prepared. Examples include hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide and potassium hydroxide, carbonates of alkali metals such as lithium carbonate, sodium carbonate and potassium carbonate, quaternary ammonium hydroxides and diethanolamine. And amines such as triethanolamine, ammonium hydroxide, quaternary phosphonium hydroxide and the like.

  Each ink of the ink set of the present invention is prepared by dissolving the above-mentioned constituents in an aqueous medium and further stirring and mixing as necessary. The stirring and mixing can be performed with a stirrer using a normal stirring blade, a magnetic stirrer, a high-speed disperser or the like, but the present invention is not affected by the production method.

  The ink set of the present invention can provide an image having good gloss and image fastness even when applied to a non-porous substrate. The non-porous substrate is not particularly limited, but can be suitably used for plastic films such as a vinyl chloride resin film, a PET film, and a polycarbonate film. On the other hand, other non-porous substrates and conventional porous media such as plain paper and inorganic coated porous media exhibit sufficient performance.

  The ink set of the present invention is capable of printing with high image quality even on a non-porous substrate. However, in order to form an image with higher image quality and higher abrasion resistance and adhesion, it is suitable for high-speed printing conditions. It is more desirable to heat the recording medium in order to cope with the above.

  The heating temperature can be changed according to the type and amount of the organic solvent contained in the ink and the minimum film-forming temperature of the resin to be added, and can also be changed according to the type of the substrate to be printed. The heating temperature is preferably high from the viewpoints of drying property and film-forming temperature. However, if the heating temperature is too high, the substrate to be printed is damaged, or non-ejection occurs due to warming up to the ink head. This is not preferable because there is a possibility that the

(Inkjet recording device)
The ink jet recording apparatus of the present invention has at least printing means for printing on a recording medium using the ink set of the present invention, and heating means for heating the printed matter. Also, energy is applied to the ink jet ink, and the ink flying means for flying the ink to record an image, and a non-porous substrate such as a vinyl chloride resin film, PET film, polycarbonate film or other non-porous substrate or other recording There may be a conveyance means for conveying the medium.

  The ink flying means is means for forming an image by applying a stimulus to the ink of the present invention and causing the ink to fly. The ink flying means is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include various recording heads (ink discharge heads), and particularly a head having a plurality of nozzle rows and a liquid storage. It is preferable to have a sub-tank that contains the liquid supplied from the tank for supplying the liquid to the head.

  The sub tank includes negative pressure generating means for generating a negative pressure in the sub tank, atmospheric release means for releasing the inside of the sub tank to the atmosphere, and detection means for detecting the presence or absence of ink based on a difference in electrical resistance. What has is preferable.

  There is no restriction | limiting in particular as said irritation | stimulation, According to the objective, it can select suitably, A heat | fever (temperature), a pressure, a vibration, light, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, heat and pressure are preferable.

  Examples of the means for generating the stimulus include a heating device, a pressurizing device, a piezoelectric element (sometimes referred to as a piezo element), a vibration generating device, an ultrasonic oscillator, a light, and the like. Specifically, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, a shape memory alloy actuator that uses a metal phase change caused by a temperature change, For example, an electrostatic actuator using an electrostatic force may be used.

  There is no restriction | limiting in particular as an aspect of ink flying, According to the kind etc. of said stimulation, it can select. For example, when the stimulus is “heat”, thermal energy corresponding to the recording signal is applied to the ink in the recording head using, for example, a thermal head, and bubbles are generated in the ink by the thermal energy. And a method of ejecting and ejecting ink as droplets from the nozzle holes of the recording head.

  Further, when the stimulus is “pressure”, for example, by applying a voltage to a piezoelectric element bonded to a position called a pressure chamber in an ink flow path in the recording head, the piezoelectric element bends and the volume of the pressure chamber is increased. And a method of ejecting and ejecting ink as droplets from the nozzle holes of the recording head. As a result, mechanical energy can be applied to the ink.

  In the present invention, it is preferable to apply a voltage to the piezo element so as to fly the ink. Since the piezo method does not generate heat, it is advantageous for flying ink containing resin, and is an effective method with less nozzle clogging, particularly when ink containing a small amount of wetting agent is used.

  In order to prevent nozzle omission, it is preferable to perform a blank scan by applying a voltage having a strength that does not eject ink to the piezo element. Furthermore, it is preferable to perform an operation of discharging ink to the ink reservoir before reaching the empty scan for one page printing.

Further, it is preferable to have a scraping means for scraping off the ink fixed to the empty discharge receptacle. As the scraping means, either a wiper or a cutter is preferable.
Further, the ink jet recording apparatus of the present invention may have a transport unit for transporting the recording medium. As the transport unit, a known transport unit such as a transport roller or a transport belt can be used.

  Further, the ink jet recording apparatus of the present invention has a heating means for fixing ink droplets on a recording medium such as a non-porous substrate. One or more of many known heating devices can be used as the heating means. Examples include forced air heating, radiant heating, conduction heating, high frequency drying, and microwave drying devices, and these may be used alone or in combination of two or more.

  Here, an aspect of the ink jet recording apparatus of the present invention will be described with reference to the drawings. In addition, although demonstrated below using a non-porous base material, in this invention, it is not limited to a non-porous base material.

FIG. 1 is a schematic view showing an example of the ink jet recording apparatus of the present invention.
The ink jet recording apparatus shown in FIG. 1 has an apparatus main body 101, a paper feed tray 102 for loading a non-porous substrate mounted on the apparatus main body 101, and an image recorded (formed) mounted on the apparatus main body 101. A paper discharge tray 103 for stocking non-porous substrates and an ink cartridge loading unit 104 are provided. On the upper surface of the ink cartridge loading unit 104, an operation unit 105 such as operation keys and a display is arranged. The ink cartridge loading unit 104 has a front cover 115 that can be opened and closed for attaching and detaching the ink cartridge 200. In FIG. 1, reference numeral 111 denotes an upper cover, and 112 denotes a front surface.

  In the apparatus main body 101, as shown in FIG. 2, a carriage 133 is slidably held in the main scanning direction by a guide rod 131 and a stay 132, which are guide members horizontally mounted on the left and right side plates. It is moved and scanned by a motor.

  The carriage 133 has a plurality of ink ejection openings of a recording head 134 including four inkjet recording heads that eject ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). Are arranged in a direction crossing the main scanning direction, and the ink droplet ejection direction is directed downward.

  As the ink jet recording head constituting the recording head 134, a piezoelectric actuator such as a piezoelectric element, a thermal actuator using phase change due to liquid film boiling using an electrothermal transducer such as a heating resistor, a metal phase due to temperature change, etc. A shape memory alloy actuator using a change, an electrostatic actuator using an electrostatic force, or the like provided as energy generating means for discharging ink can be used.

  In addition, the carriage 133 is equipped with a sub tank 135 for each color for supplying ink of each color to the recording head 134. The ink of the ink set is supplied to the sub tank 135 from the ink cartridge 200 of the present invention loaded in the ink cartridge loading unit 104 via the ink supply tube and replenished.

  On the other hand, the nonporous substrate stacking unit 141 is used as a sheet feeding unit for feeding the nonporous substrate 142 loaded on the nonporous substrate stacking unit (pressure plate) 141 of the sheet feeding tray 102. A half-moon roller (sheet feeding roller 143) that separates and feeds the base material 142 one by one, and a sheet separation roller 144 made of a material having a large friction coefficient are provided opposite to the sheet feeding roller 143. It is biased toward the roller 143 side.

  A conveying belt 151 for electrostatically adsorbing and conveying the non-porous substrate 142 as a conveying unit for conveying the non-porous substrate 142 fed from the sheet feeding unit below the recording head 134. A counter roller 152 for transporting the non-porous base material 142 fed from the paper supply unit via the guide 145 between the transport belt 151 and a non-porous base material 142 fed substantially vertically upward Is provided with a conveyance guide 153 for changing the direction of the belt by approximately 90 ° and following the conveyance belt 151, and a tip pressure roller 155 urged toward the conveyance belt 151 by the pressing member 154. A charging roller 156 is provided as charging means for charging the surface 151.

  The conveyor belt 151 is an endless belt, is stretched between a heater-type conveyor roller 157 and a tension roller 158, and can circulate in the belt conveyance direction. The transport belt 151 includes, for example, a surface layer serving as a non-porous substrate adsorption surface formed of a resin material having a thickness of about 40 μm that is not subjected to resistance control, such as a copolymer of tetrafluoroethylene and ethylene (ETFE) And a back layer (medium resistance layer, earth layer) which is made of the same material as the surface layer and is subjected to resistance control by carbon. A heater-type guide member 161 is disposed on the back side of the conveyance belt 151 so as to correspond to a printing area by the recording head 134.

  Note that a separation claw 171 for separating the non-porous substrate 142 from the transport belt 151 and a discharge roller 172 serve as a discharge unit for discharging the non-porous substrate 142 recorded by the recording head 134. And the paper discharge roller 173, the non-porous substrate 142 is dried with hot air by the fan heater 174, and then output to the paper discharge tray 103 below the paper discharge roller 172.

  A double-sided paper feeding unit 181 is detachably mounted on the back surface of the apparatus main body 101. The double-sided paper feeding unit 181 takes in the non-porous substrate 142 returned by the reverse rotation of the transport belt 151, reverses it, and feeds it again between the counter roller 152 and the transport belt 151. A manual paper feed unit 182 is provided on the upper surface of the duplex paper feed unit 181.

  In the inkjet recording apparatus of the present invention, the non-porous substrate 142 is separated and fed one by one from the sheet feeding unit, and the non-porous substrate 142 fed substantially vertically upward is guided by the guide 145, It is sandwiched between the transport belt 151 and the counter roller 152 and transported. Further, the leading end is guided by the conveying guide 153 and pressed against the conveying belt 151 by the leading end pressure roller 155, and the conveying direction is changed by approximately 90 °.

  At this time, the conveyance belt 151 is charged by the charging roller 156, and the non-porous substrate 142 is electrostatically attracted to the conveyance belt 151 and conveyed. Therefore, by driving the recording head 134 according to the image signal while moving the carriage 133, ink droplets are ejected onto the stopped non-porous substrate 142 to record one line, and the non-porous substrate is recorded. After the material 142 is conveyed by a predetermined amount, the next line is recorded. Upon receiving a recording end signal or a signal indicating that the rear end of the non-porous substrate 142 has reached the recording area, the recording operation is completed, and the non-porous substrate 142 is discharged onto the discharge tray 103.

  Here, an example is described in which the present invention is applied to a serial (shuttle type) ink jet recording apparatus that is scanned by a carriage, but the present invention can be similarly applied to a line type ink jet recording apparatus having a line type head.

  The ink jet recording apparatus of the present invention can be applied to various types of recording by the ink jet recording method, and is particularly preferably applied to, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier multifunction machine, and the like. Can do.

(Recorded material)
The recorded matter of the present invention has information or an image recorded on a recording medium using the ink set of the present invention. There is no restriction | limiting in particular as said recording medium, According to the objective, it can select suitably, For example, a plain paper, glossy paper, special paper, cloth, a film, an OHP sheet etc. are mentioned.

  Further, according to the ink set of the present invention, it is possible to provide an image having good gloss and image fastness particularly when applied to a non-porous substrate. The non-porous substrate is not particularly limited, but is somewhat water like a recording medium made of a hydrophobic resin that hardly absorbs water such as polyvinyl chloride, PET, polypropylene, polyethylene, polycarbonate, or a printing paper such as coated paper. For example, there may be mentioned a recording medium that absorbs water but has a slow absorption speed and causes trouble without drying of the water-based ink in the printing process of ordinary ink jet printing in a normal temperature and humidity environment.

  The said recorded matter may be used individually by 1 type, and may use 2 or more types together. The recorded matter obtained by the present invention has high glossiness, excellent scratch resistance, etc., and can be suitably used for various applications.

(Inkjet recording method)
The ink jet recording method of the present invention includes a printing process for printing on a recording medium by applying either thermal energy or mechanical energy to each ink of the ink jet ink set of the present invention, and heating for heating the printed matter. Process. In the printing process, the recording medium is preferably a non-porous substrate. When the ink of the present invention is applied to a non-porous substrate, it can provide an image with good gloss and image fastness. Here, the heat energy and the mechanical energy described above can be used.

  The printing means used in the printing process is not particularly limited, and examples include the flying means. The heating means used in the heating step is not particularly limited, and examples thereof include forced air heating, radiant heating, conduction heating, high frequency drying, and microwave drying apparatuses as described above. These may be used alone or in combination of two or more.

  As described above, the heating temperature can be changed according to the type and amount of the organic solvent contained in the ink and the minimum film-forming temperature of the resin to be added, and further changed depending on the type of the substrate to be printed. can do. The heating temperature is preferably high from the viewpoints of drying property and film-forming temperature. However, if the heating temperature is too high, the substrate to be printed is damaged, or non-ejection occurs due to warming up to the ink head. This is not preferable because there is a possibility that the

  Hereinafter, the present invention will be described with reference to examples and comparative examples. In addition, this invention is not limited to the Example illustrated here.

<Preparation of polycarbonate-modified urethane resin emulsion A>
In a reaction vessel into which a stirrer, a reflux condenser and a thermometer were inserted, 1500 g of polycarbonate diol (reaction product of 1,6-hexanediol and dimethyl carbonate), 220 g of 2,2-dimethylolpropionic acid (DMPA) and dipropylene glycol 1347 g of dimethyl ether (bp 171 ° C.) was charged under a nitrogen stream and heated to 60 ° C. to dissolve DMPA.

  1,445 g of 4,4′-dicyclohexylmethane diisocyanate and 2.6 g of dibutyltin dilaurate (catalyst) were added and heated to 90 ° C. and subjected to urethanization for 5 hours to obtain an isocyanate-terminated urethane prepolymer.

  The reaction mixture was cooled to 80 ° C., 4340 g was extracted from the mixture in which 149 g of triethylamine was added and mixed, and added to a mixed solution of 5400 g of water and 15 g of triethylamine with vigorous stirring.

  Next, 1500 g of ice is added, 626 g of 35% by mass of 2-methyl-1,5-pentanediamine aqueous solution is added to carry out chain extension reaction, and the solvent is distilled off so that the solid content concentration becomes 30%. Modified urethane resin emulsion A (urethane resin component 30%, water 64%, dipropylene glycol dimethyl ether 6%) was obtained.

The obtained polycarbonate-modified urethane resin emulsion A was applied on a slide glass so as to have a film thickness of 10 μm, dried at 100 ° C. for 30 minutes to form a resin film, and a micro surface hardness tester (FISCHERSCOPE HM2000, manufactured by Fischer) was used. The Martens hardness when the Vickers indenter was pushed in with a load of 9.8 mN was 120 N / mm ² .

-Preparation of yellow pigment-containing polymer particle dispersion-
After sufficiently replacing the inside of the 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas introduction tube, reflux tube and dropping funnel with nitrogen gas, 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer (manufactured by Toa Gosei Co., Ltd., trade name: AS-6) and 0.4 g of mercaptoethanol were charged and heated to 65 ° C. Next, 100.8 g of styrene, 25.2 g of acrylic acid, 108.0 g of lauryl methacrylate, 36.0 g of polyethylene glycol methacrylate, 60.0 g of hydroxyethyl methacrylate, styrene macromer (manufactured by Toa Gosei Co., Ltd., trade name: AS-6) 36 A mixed solution of 0.0 g, mercaptoethanol 3.6 g, azobisdimethylvaleronitrile 2.4 g and methyl ethyl ketone 18 g was dropped into the flask over 2.5 hours. After completion of dropping, a mixed solution of 0.8 g of azobisdimethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 g of azobisdimethylvaleronitrile was added, and further aging was performed for 1 hour. After completion of the reaction, 364 g of methyl ethyl ketone was added to the flask to obtain 800 g of a polymer solution having a concentration of 50%.

-Preparation of yellow pigment-containing polymer particle dispersion I (average particle size 190 nm) 28 g of the polymer solution prepared above and 26 g of yellow pigment (CI Pigment Yellow 74, manufactured by Dainichi Seika Kogyo Co., Ltd.), 1 mol / L of hydroxylated water After sufficiently stirring 13.6 g of a potassium solution, 20 g of methyl ethyl ketone, and 30 g of ion-exchanged water, the mixture was kneaded 10 times using a three-roll mill. The obtained paste was put into 200 g of ion-exchanged water and sufficiently stirred, and then methyl ethyl ketone and water were distilled off using an evaporator to obtain an aqueous dispersion of yellow pigment-containing polymer particles having a solid content of 20% by mass. . About the obtained polymer particle, the average particle diameter (D50) measured with the particle size distribution measuring apparatus (Microtrac UPA, Nikkiso Co., Ltd. product) was 190 nm.

-Preparation of yellow pigment-containing polymer particle dispersion II (average particle size 120 nm) In preparation of yellow pigment-containing polymer particle dispersion I, yellow pigment-containing polymer particle dispersion I was changed except that the number of kneading of the three roll mill was changed from 10 to 15 times. In the same manner as in the preparation of the polymer particle dispersion I, an aqueous dispersion of yellow pigment-containing polymer particles having a solid content of 20% by mass was obtained. About the obtained polymer particle, the average particle diameter (D50) measured with the particle size distribution measuring apparatus (Microtrac UPA, Nikkiso Co., Ltd. product) was 120 nm.

-Preparation of yellow pigment-containing polymer particle dispersion III (average particle size 70 nm) In preparation of yellow pigment-containing polymer particle dispersion I, yellow pigment-containing polymer particle dispersion I was changed except that the number of kneading of the three roll mill was changed from 10 to 20 times. In the same manner as in the preparation of the polymer particle dispersion I, an aqueous dispersion of yellow pigment-containing polymer particles having a solid content of 20% by mass was obtained. About the obtained polymer particle, the average particle diameter (D50) measured with the particle size distribution measuring apparatus (Microtrac UPA, Nikkiso Co., Ltd. product) was 70 nm.

・ Preparation of yellow pigment-containing polymer particle dispersion IV (average particle size 240 nm) In preparation of yellow pigment-containing polymer particle dispersion I, except that the number of kneading of the three-roll mill was changed from 10 to 7 times In the same manner as in the preparation of the polymer particle dispersion I, an aqueous dispersion of yellow pigment-containing polymer particles having a solid content of 20% by mass was obtained. About the obtained polymer particle, the average particle diameter (D50) measured with the particle size distribution measuring apparatus (Microtrac UPA, Nikkiso Co., Ltd. product) was 240 nm.

-Preparation of yellow pigment-containing polymer particle dispersion V (average particle size 300 nm) In preparation of yellow pigment-containing polymer particle dispersion I, yellow pigment-containing polymer particle dispersion I was changed except that the number of kneading of the three-roll mill was changed from 10 times to 4 times. In the same manner as in the preparation of the polymer particle dispersion I, an aqueous dispersion of yellow pigment-containing polymer particles having a solid content of 20% by mass was obtained. About the obtained polymer particle, the average particle diameter (D50) measured with the particle size distribution measuring apparatus (Microtrac UPA, Nikkiso Co., Ltd. product) was 300 nm.

Example 1
-Preparation of yellow ink-
Using the yellow pigment-containing polymer particle dispersion I, a yellow ink was prepared by mixing and stirring with the following formulation and then filtering through a 0.2 μm polypropylene filter.

Yellow pigment-containing polymer particle dispersion I 15 parts by mass Polycarbonate-modified urethane resin emulsion A 25 parts by mass (including 1.5 parts by mass of dipropylene glycol dimethyl ether (bp 171 ° C.))
Acrylic resin emulsion 2 parts by mass (Boncoat R-3380-E manufactured by DIC)
Surfactant 2 parts by mass (nonionic surfactant Softanol EP-5035 manufactured by Nippon Shokubai Co., Ltd.)
1,4-butanediol 25 parts by weight 3-methyl-1,3-butanediol 4 parts by weight Antiseptic / antifungal agent Proxel LV (manufactured by Avicia) 0.1 part by weight Ion-exchanged water 26.9 parts by weight

-Preparation of carbon black pigment-containing polymer particle dispersion-
In the preparation of the yellow pigment-containing polymer particle dispersion I, the yellow pigment (CI Pigment Yellow 74, manufactured by Dainichi Seika Kogyo Co., Ltd.) is mixed with carbon black (Degussa Co., FW100), and the number of kneadings of three roll mills is adjusted. A carbon black pigment-containing polymer particle dispersion was prepared in the same manner as the preparation of the yellow pigment-containing polymer particle dispersion I except that the number of times was changed from 10 to 20.
About the polymer particle in the obtained carbon black pigment containing polymer particle dispersion, the average particle diameter (D50) measured with the particle size distribution measuring apparatus (the Nikkiso Co., Ltd. make, Nanotrac UPA-EX150) was 124 nm.

-Preparation of black ink-
The carbon black pigment-containing polymer particle dispersion was mixed and stirred with the following formulation, followed by filtration with a 0.2 μm polypropylene filter to prepare a black ink.
Carbon black pigment-containing polymer particle dispersion 15 parts by mass Polycarbonate-modified urethane resin emulsion A 25 parts by mass (including 1.5 parts by mass of dipropylene glycol dimethyl ether (bp 171 ° C.))
Acrylic resin emulsion 2 parts by mass (Boncoat R-3380-E manufactured by DIC)
1 part by weight of surfactant (nonionic surfactant, softanol EP-5035, manufactured by Nippon Shokubai Co., Ltd.)
1,4-butanediol 25 parts by weight 3-methyl-1,3-butanediol 4 parts by weight Antiseptic / antifungal agent Proxel LV (manufactured by Avicia) 0.1 part by weight Ion-exchanged water 27.9 parts by weight

-Preparation of polymer particle dispersion containing magenta pigment-
In the preparation of the yellow pigment-containing polymer particle dispersion I, a yellow pigment (CI Pigment Yellow 74, manufactured by Dainichi Chemical Industries) was used as a magenta pigment (CI Pigment Red 122, manufactured by Dainichi Chemical Industries). In addition, a magenta pigment-containing polymer particle dispersion was prepared in the same manner as the preparation of the yellow pigment-containing polymer particle dispersion I, except that the number of kneadings in the three-roll mill was changed from 10 to 20.
About the polymer particle in the obtained magenta pigment containing polymer particle dispersion, the average particle diameter (D50) measured with the particle size distribution analyzer (the Nikkiso Co., Ltd. make Nanotrac UPA-EX150) was 48 nm.

-Magenta ink production-
A magenta ink was produced in the same manner as the black ink except that the carbon black pigment-containing polymer particle dispersion was changed to the magenta pigment-containing polymer particle dispersion in the production of the black ink.

-Preparation of cyan pigment-containing polymer particle dispersion-
In the preparation of the yellow pigment-containing polymer particle dispersion I, a yellow pigment (CI Pigment Yellow 74, manufactured by Dainichi Seika Kogyo Co., Ltd.) was used as a cyan pigment (CI Pigment Blue 15: 3, Dainichi Seika Kogyo Co., Ltd.). The cyan pigment-containing polymer particle dispersion was prepared in the same manner as the preparation of the yellow pigment-containing polymer particle dispersion I, except that the number of kneading in the three-roll mill was changed from 10 to 20 times.
About the polymer particle in the obtained cyan pigment containing polymer particle dispersion, the average particle diameter (D50) measured with the particle size distribution measuring apparatus (the Nikkiso Co., Ltd. make, Nanotrac UPA-EX150) was 80 nm.

-Production of cyan ink-
A cyan ink was prepared in the same manner as the black ink except that the carbon black pigment-containing polymer particle dispersion was changed to the cyan pigment-containing polymer particle dispersion in the preparation of the black ink.

  When the average particle diameter of the pigment-containing polymer particles in each ink was measured, it was the same as the average particle diameter of the pigment-containing polymer particles in the pigment-containing polymer particle dispersion. The measuring method is the same as the average particle diameter of the pigment-containing polymer particles in the pigment-containing polymer particle dispersion.

The following evaluation was performed about the ink produced as mentioned above.
Table 1 shows the composition of the yellow ink (the numerical value indicates parts by mass), the ratio of the average particle diameter of the pigment with other colors, and the evaluation results. In Table 1, the blank indicates “no blending”.
<Drying evaluation>
The prepared ink is filled in an ink jet printer having a heating fan (IPSiO GXe5500 remodeled machine manufactured by Ricoh Co., Ltd.), and a yellow solid color image is printed on a polyvinyl chloride sheet IJ5331 (manufactured by Sumitomo 3M). An image was formed by drying at 60 ° C. The filter paper was pressed against the solid part after drying, and the determination was made according to the following criteria from the degree of ink transfer to the filter paper.
A: Transfer to filter paper disappears under drying conditions at 60 ° C. for 15 minutes.
B: Transfer to filter paper disappears under drying conditions of 60 ° C. for 30 minutes.
C: Transfer to filter paper disappears under drying conditions at 60 ° C. for 60 minutes.
D: Transfer to filter paper does not disappear even under drying conditions at 60 ° C. for 60 minutes.

<Image gloss evaluation>
The prepared ink is filled in an ink jet printer having a heating fan (IPSiO GXe5500 remodeled machine manufactured by Ricoh Co., Ltd.), and a yellow solid color image is printed on a polyvinyl chloride sheet IJ5331 (manufactured by Sumitomo 3M). An image was formed by drying at 60 ° C. The 60 ° glossiness of the solid image portion was measured with a gloss meter (manufactured by BYK Gardener, 4501), and judged according to the following criteria.
A: 60 ° gloss is greater than 100%.
B: 60 ° glossiness is 81% to 100%.
C: 60 ° gloss is 60% to 80%.
D: 60 ° gloss is less than 60%

<Abrasion resistance evaluation>
The prepared ink is filled in an ink jet printer having a heating fan (IPSiO GXe5500 remodeled machine manufactured by Ricoh Co., Ltd.), and a yellow solid color image is printed on a polyvinyl chloride sheet IJ5331 (manufactured by Sumitomo 3M). An image was formed by drying at 60 ° C. The solid part was rubbed with dry cotton (Kanakin No. 3) under a load of 400 g, and the rub resistance was determined according to the following criteria.
A: The image does not change even after rubbing 50 times or more.
B: Some scratches remain after rubbing 50 times, but the image density is not affected, and there is no problem in actual use.
C: The image density decreases during rubbing 21 to 50 times.
D: Image density is lowered by rubbing 20 times or less.

<Ethanol resistance evaluation>
The prepared ink is filled in an ink jet printer having a heating fan (IPSiO GXe5500 remodeled machine manufactured by Ricoh Co., Ltd.), and a yellow solid color image is printed on a polyvinyl chloride sheet IJ5331 (manufactured by Sumitomo 3M). An image was formed by drying at 60 ° C. A cotton swab was impregnated with a 50% aqueous solution of ethanol, the solid part of the image was rubbed 20 times, and the degree of peeling of the coating film on the solid part was determined according to the following criteria.
A: Peeling is not seen at all on the solid part, and dirt is not seen on the cotton swab.
B: Peeling is not found on the solid part, but the dirt is slightly adhered to the cotton swab.
C: Ink melted out in the solid portion.
D: The solid part of the ink is peeled off and a part of the PVC (polyvinyl chloride) film is exposed.

<Light resistance evaluation>
The prepared ink is filled in an ink jet printer having a heating fan (IPSiO GXe5500 remodeled machine manufactured by Ricoh Co., Ltd.), and a yellow solid color image is printed on a polyvinyl chloride sheet IJ5331 (manufactured by Sumitomo 3M). An image was formed by drying at 60 ° C. Each image sample obtained was subjected to a weatherometer Ci35A (Atlas Co., xenon light source) using a type S borosilicate glass for both the outer filter and inner filter at a black panel temperature of 89 ° C., 50% RH and an exposure of 2600 kJ / An exposure test was conducted until m ² , the fading state before and after the test was measured with X-Rite 938 (manufactured by X-Rite), and light resistance (color difference ΔE * ab) was obtained from the following formula. Sex was judged.
ΔE * ab = (ΔL * 2 + Δa * 2 + Δb * 2) ^1/2
A: ΔE * ab ≦ 5
B: 5 <ΔE * ab ≦ 10
C: 10 <ΔE * ab ≦ 20
D: 20 <ΔE * ab

<Color bleed evaluation (bleed resistance)>
The prepared ink was filled in an inkjet printer having a heating fan (IPSiO GXe5500 modified machine manufactured by Ricoh Co., Ltd.), and after printing a black solid image and a yellow solid image on a polyvinyl chloride sheet IJ5331 (manufactured by Sumitomo 3M), An image was formed by drying at 60 ° C. with a heating fan. The boundary between black solid and yellow solid was observed, and the image quality was evaluated according to the following criteria in comparison with the rank sample.
〔Evaluation criteria〕
A: No color mixture.
B: Although there is color mixture, there is no practical problem.
C: There is a little color mixing.
D: There are many mixed colors.

(Examples 2 to 8)
In Example 1, the yellow ink was prepared by changing to the formulation shown in Table 1, and in black ink, magenta ink, and cyan ink, 1,4-butanediol was listed in Table 1 in the same manner as the yellow ink. An ink set was obtained in the same manner as in Example 1 except that the water-soluble organic solvent was changed. The obtained ink set was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 9
In Example 1, the black pigment-containing polymer particle dispersion having an average particle diameter of 78 nm obtained by changing the number of kneading operations from 20 to 25 times for the carbon black pigment-containing polymer particle dispersion (average particle diameter 124 nm) of the black ink A black ink was obtained in the same manner except that the body was changed.
In Example 1, the yellow ink was changed to the formulation shown in Table 1, and the black ink was changed to a black ink having an average particle size of the pigment-containing polymer particles of 78 nm. Obtained. The obtained ink set was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Example 10)
An ink set was obtained in the same manner as in Example 1, except that the yellow ink was prepared by changing the formulation shown in Table 1 in Example 1. The obtained ink set was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Examples 1-3)
An ink set was obtained in the same manner as in Example 1, except that the yellow ink was prepared by changing the formulation shown in Table 1 in Example 1. The obtained ink set was evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Comparative Example 4)
In Example 1, the yellow ink was prepared by changing to the formulation shown in Table 1. In the black ink, magenta ink, and cyan ink, ion-exchanged water was used instead of the polycarbonate-modified urethane resin emulsion in the same manner as the yellow ink. An ink set was obtained in the same manner as in Example 1 except for the addition. The obtained ink set was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 5)
An ink set was obtained in the same manner as in Example 1, except that the yellow ink was prepared by changing the formulation shown in Table 1 in Example 1. The obtained ink set was evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Comparative Example 6)
In Example 1, the yellow ink was changed to the formulation shown in Table 1, and the black ink, the magenta ink, and the cyan ink were changed from 1,4-butanediol to glycerin as in the yellow ink. An ink set was obtained in the same manner as in Example 1, except that 25 parts by mass of the polycarbonate-modified urethane resin emulsion was changed to 25 parts by mass of the ester / ether-modified urethane resin emulsion (Superflex 150). The obtained ink set was evaluated in the same manner as in Example 1. The results are shown in Table 2.

  According to the present invention, it is possible to obtain an ink set that exhibits good drying properties even when printed on a non-porous substrate and has a high gloss, scratch resistance, ethanol resistance, and bleeding resistance on the printed portion. Can do.

DESCRIPTION OF SYMBOLS 101 Main body 102 Paper feed tray 103 Paper discharge tray 104 Ink cartridge loading part 105 Operation part 111 Upper cover 112 Front surface 115 Front cover 131 Guide rod 132 Stay 133 Carriage 134 Recording head 135 Sub tank 141 Non-porous base material loading part (pressure plate)
142 Non-porous substrate 143 Feed roller 144 Separation pad 145 Guide 151 Transport belt 152 Counter roller 153 Transport guide 154 Press member 155 Tip pressure roller 156 Charging roller 157 Transport roller 158 Tension roller 161 Guide member 171 Separation claw 172 Paper discharge Roller 173 Paper discharge roller 174 Fan heater 181 Double-sided paper feed unit 182 Manual paper feed unit 200 Ink cartridge

JP 2011-201230 A JP 2009-209270 A JP 2009-203333 A

Claims (9)

  An inkjet ink set used for an inkjet recording method, wherein the ink set is composed of at least a yellow ink, a cyan ink, a magenta ink, and a black ink, and each of the inks includes at least water, an organic solvent, and pigment-containing polymer particles. The average particle size (D50) of the pigment-containing polymer particles in the yellow ink is greater than the average particle size of the pigment-containing polymer particles in all other three inks. An inkjet ink set characterized by being 1.5 to 5.0 times larger.   The inkjet ink set according to claim 1, wherein an average particle diameter (D50) of the pigment-containing polymer particles in the yellow ink is 0.10 µm or more and 0.25 µm or less.   The inkjet ink set according to claim 1 or 2, wherein the content ratio of the surfactant in the yellow ink is larger than the content ratio of the surfactant in the other inks.   The ratio of the content ratio (A) based on the weight basis of the surfactant in the yellow ink to the content ratio (B) based on the weight basis of the surfactant in the other ink is (B) / (A) = 1. The inkjet ink set according to any one of claims 1 to 3, wherein the ink set is in a range of 0.0 / 1.3 to 1.0 / 3.0.   The organic solvent is at least one selected from the group consisting of 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 2,3-butanediol. The inkjet ink set according to claim 1, wherein the inkjet ink set is contained.   6. A printing process for printing on a recording medium by applying either thermal energy or mechanical energy to each ink of the ink jet ink set according to claim 1, and heating for heating the printed matter. And an ink jet recording method.   The inkjet recording method according to claim 6, wherein the recording medium is a non-porous substrate.   An ink jet recorded product formed using the ink jet ink set according to claim 1.   An inkjet recording apparatus comprising: a printing unit that prints on a recording medium using the inkjet ink set according to claim 1; and a heating unit that heats a printed matter.

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