JP2005255711A - Ink composition, inkjet recording method and inkjet-recorded matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ink composition having excellent jetting stability. <P>SOLUTION: This aqueous ink composition comprises a coloring material, water, an organic solvent, a compound represented by formula (1) (wherein (m) and (n) are each an integer of 1-5), and a reduced form of a disaccharide and/or a derivative thereof. The ink composition is endowed with excellent jetting stability. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink composition, an ink jet recording method, and an ink jet recorded material.

In recent years, an ink composition or the like applied to a recording apparatus such as an ink jet recording apparatus has become a water-based type. With respect to such an aqueous ink composition, it is an important factor that the ink composition is stably ejected from the nozzles of the printer head (having ejection stability). In order to ensure ejection stability, it is necessary to maintain the dispersion form and viscosity of the ink components. Therefore, conventionally, a compound excellent in water retention, such as a polyhydric alcohol containing saccharides, has been added to the ink composition as a wetting agent in order to stabilize the aqueous dispersion. As such a wetting agent for an ink composition, various monosaccharides and disaccharides and derivatives thereof are generally known as saccharides (Patent Document 1), and polyhydric alcohols other than saccharides. Is well known as trimethylolpropane (Patent Document 2).
JP 2001-234098 A JP-A-3-152171

  However, in order to meet the recent demand for higher image quality, ink compositions have been required to have better ejection stability. Various types of wetting agents have been known so far, but no attempt has been made to combine different types of wetting agents such as saccharides and other polyhydric alcohols. It was never known that sex could be obtained.

  Therefore, an object of the present invention is to provide an ink composition, an ink jet recording method, and an ink jet recorded material having excellent ejection stability.

  The present inventors examined various saccharides and derivatives thereof, and can significantly improve clogging reliability by combining a reduced form of disaccharides and / or derivatives thereof with a certain polyhydric alcohol, Obtaining the knowledge that excellent ejection stability can be imparted to the ink composition, the present invention has been completed. That is, according to the present invention, the following means are provided. This ink composition is preferably used for an ink jet recording apparatus.

（ただし、上記式において、ｍ及びｎはそれぞれ１〜５の整数を表す。）
二糖類の還元体及び／又はその誘導体と、を含有する、組成物が提供される。また、前記着色材は、染料及び顔料分散体から選択される１種あるいは２種以上である、上記組成物も提供される。さらに、前記二糖類の還元体は、ラクチトール並びにその水和物及びマルチトール並びにその水和物からなる群から選択される１種あるいは２種以上である、上記組成物も提供される。さらにまた、前記一般式（１）で表される化合物は、１，１，１−トリメチロールプロパンである、上記いずれかの組成物も提供される。 According to the present invention, a water-based ink composition, which is a colorant, water, an organic solvent, a compound represented by the following general formula (1),

(In the above formula, m and n each represent an integer of 1 to 5.)
A composition containing a reduced form of a disaccharide and / or a derivative thereof is provided. Moreover, the said composition is also provided with the said coloring material which is 1 type (s) or 2 or more types selected from a dye and a pigment dispersion. Further, the above-mentioned composition is provided in which the reduced form of the disaccharide is one or more selected from the group consisting of lactitol, hydrates thereof, maltitol and hydrates thereof. Furthermore, any of the above compositions wherein the compound represented by the general formula (1) is 1,1,1-trimethylolpropane is also provided.

  The total amount of the compound represented by the general formula (1) and the reduced form of the disaccharide and / or a derivative thereof is 1 wt% or more and 30 wt% or less with respect to the total amount of the ink composition. Also provided are such compositions. Furthermore, any one of the above compositions containing 5 parts by weight or more and 2000 parts by weight or less of the reduced form of the disaccharide and / or a derivative thereof with respect to 100 parts by weight of the compound represented by the general formula (1) is also provided. Is done.

  According to the present invention, there is provided an ink jet recording method comprising the step of applying any one of the above aqueous ink compositions to a recording medium surface by an ink jet recording method. There is also provided a recorded matter having a dot pattern by an ink jet recording method comprising the aqueous ink composition according to any one of claims 1 to 7 on the surface of the recording medium.

  The ink composition of the present invention contains a colorant, water, an organic solvent, a trialkanol alkane represented by the general formula (1), a disaccharide reductant and / or a derivative thereof. Yes. Hereinafter, the essential components of the ink composition of the present invention will be described, then other components will be described, and the inkjet recording method of the present invention using the ink composition of the present invention and the inkjet recorded product will be described. In the following description, unless otherwise specified, “%” means wt (weight)%, “part” means part by weight, and “ratio” means weight ratio.

(Water-based ink composition)
(Coloring material)
The ink composition may contain a dye or a pigment as a colorant. As the dye used in the present invention, a dye insoluble or hardly soluble in water is preferably used. Specific examples of the colorant of the present invention include oil-soluble dyes, basic dyes, disperse dyes, vat dyes, sulfur dyes, organic solvent-soluble dyes, and reactive dyes.

  The pigment is not particularly limited, and any of inorganic pigments and organic pigments can be used. As the inorganic pigment, metals such as copper oxide, iron oxide and titanium oxide, carbon blacks such as furnace black, lamp black, acetylene black and channel black can be used. Organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments. Thioindigo pigments, isoindolinone pigments, quinofuranone pigments, etc.), dye chelates (basic dye type chelates, acidic dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black, and the like.

  Examples of pigments for black ink include iron oxides such as C.I. I. Pigment Black 11 is a carbon black C.I. I. Pigment Black 7 is an aniline black C.I. I. Pigment Black 1 can be mentioned, and more specifically, the following carbon black is exemplified. That is, no. 2300, no. 900, MCF88, No. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, No2200B and the like are Raven5750, Raven5250, Raven5000, Raven3500, Raven1255, Raven700, etc. manufactured by Columbia, Regal 400R, Regal 330R, Regal 1660R, MolarL6601 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. are Color Black FW2, Color Black FW2V, Color Black FW2V, Color Black FW2V, Color Black FW2V, Color Black FW2V, Color Black FW2V S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 and the like can be used.

  Examples of pigments used in yellow ink include C.I. I. Pigment yellow 1 (fast yellow G), 2, 3, 12 (disazo yellow AAA), 13, 14, 16, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 73, 74 75, 81, 83 (disazo yellow HR), 93, 95, 97, 98, 100, 101, 104, 108, 109, 110, 114, 117, 120, 128, 129, 138, 151, 153, 154, Examples of pigments used in magenta ink include C.I. I. Pigment Red 1, 2, 3, 5, 7, 12, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48 (Ca), 48 (Mn), 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 (Ca), 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81 (Rhodamine 6G rake), 83, 88, 101 (Bengara), 104, 105, 106 , 108 (cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 17 , 179,184,185,190,193,202,209,219, as the pigment used in cyan ink, C. I. Pigment Blue 1, 2, 3, 15 (phthalocyanine blue R), 15: 1, 15: 2, 15: 3 (phthalocyanine blue G), 15: 4, 15: 6 (phthalocyanine blue E), 15:34, 16 17: 1, 22, 56, 60, 63, C.I. I. Vat Blue 4, C.I. I. Vat Blue 60, pigments used in green ink include C.I. I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like. The pigment particle size is preferably a pigment composed of particles of 0.5 μm or less, more preferably a pigment composed of particles of 0.01 to 0.15 μm. The kind of pigment is not limited to these. The content of these pigments in the ink composition is preferably in the range of 1 to 8%, more preferably in the range of 2 to 8%.

  In order to obtain dispersion stability, a self-dispersing pigment may be used without using a resin or a dispersant. In this case, a sufficient number of functional groups having a charge is intentionally introduced to the surface of the pigment. Examples of functional groups include carboxylic acid groups, sulfonic acid groups, protonated amino groups, and the like.

  These dyes and pigments may be contained in the ink composition in a state where the pigment is coated with a resin. In this case, the resin covering the pigment is made of a polyacrylic acid ester, a styrene-acrylic acid copolymer, a vinyl resin such as polystyrene (vinyl polymer), polyester, polyamide, polyimide, a silicon-containing resin, or a sulfur-containing resin. The main component is preferably one or more selected from the group. Accordingly, since the resin can stably coat the pigment, stable ejection can be obtained and a good image can be obtained by using the pigment coated with the above-described resin. The form in which the pigment is coated with the resin is a preferred form of the pigment dispersion.

  As such a resin, it is preferable to use a polymer obtained by polymerizing a monomer or oligomer having an acryloyl group, a methacryloyl group, a vinyl group or an allyl group as a double bond according to a known polymerization method using a polymerization initiator. it can. Here, examples of the monomer include styrene, tetrahydrofurfuryl acrylate, butyl methacrylate, (α, 2, 3 or 4) -alkyl styrene, (α, 2, 3 or 4) -alkoxy styrene, 3,4-dimethyl. Styrene, α-phenylstyrene, divinylbenzene, vinylnaphthalene, dimethylamino (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropylacrylamide, N, N-dimethylaminoethyl acrylate, acryloylmorpholine, N, N- Dimethylacrylamide, N-isopropylacrylamide, N, N-diethylacrylamide, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, ethylhexyl (meth) acrylate , Octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, other alkyl (meth) acrylates, methoxydiethylene glycol (meth) acrylate, ethoxy group, propoxy group, butoxy group diethylene glycol or polyethylene glycol ( (Meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, hydroxyalkyl (meth) acrylate, fluorine-containing, chlorine-containing or silicon-containing (meth) acrylate, ( Monofunctional monomers such as (meth) acrylamide, maleic acid amide and (meth) acrylic acid can be used. When introducing a crosslinked structure into the resin, (mono, di, tri, tetra, poly) ethylene glycol di (meth) acrylate, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol 1,8-octanediol and 1,10-decanediol, etc. (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin (di, tri) (meth) acrylate, ethylene oxide adducts of bisphenol A or bisphenol F A compound having an acrylic group or a methacryl group such as di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, or the like can be used.

  Polymerization initiators include potassium persulfate and ammonium persulfate, hydrogen persulfate, azobisisobutyronitrile, benzoyl peroxide, dibutyl peroxide, peracetic acid, cumene hydroperoxide, t-butylhydroxyperoxide, paraffin. A general initiator used for radical polymerization such as menthane hydroxyperoxide can be used, but a water-soluble polymerization initiator is preferably used.

  Examples of the method of coating the pigment with such a resin include a phase inversion emulsification method, an acid folding method, and a forced emulsification method. As a specific example of the phase inversion emulsification method, a self-water dispersible resin (self-water dispersible resin) in which some acid groups are neutralized with a base is dissolved in an organic solvent, and a pigment is dispersed or dissolved in this solution. A method of performing phase inversion emulsification by mixing a colored resin solution obtained in this manner and an aqueous medium containing water as an essential component is known. At the time of phase inversion emulsification, pigment particles coated with the above-mentioned resin are generated. Therefore, the pigment coated with the resin can be suitably obtained by subsequently removing the organic solvent from the aqueous medium. Here, as the self-water dispersible resin, a copolymer of (meth) acrylic acid and at least one monomer selected from the group consisting of styrene having an acid value of 20 to 200 KOHg / g, substituted styrene, and (meth) acrylic acid ester. A polymer can be preferably used.

（ただし、上記式において、ｍ及びｎはそれぞれ１〜５の整数を表す。） (First wetting agent: trialkanol alkane)
As the first wetting agent, a compound (trialkanol alkane) represented by the following general formula (1) is used.

(In the above formula, m and n each represent an integer of 1 to 5.)

  Such a compound ensures the moisture retention and wettability of the ink composition. The compound includes 1,1,1-trimethylolpropane (2-ethyl-2- (hydroxyethyl) -1,2-propanediol), 1,1,1-trimethylolethane, 1,1,2-trimethyl Examples include methylolpropane and 1,1,2-trimethylolethane. One or more of these can be used, but 1,1,1-trimethylolpropane is preferably used.

(Second wetting agent: reduced form of disaccharide and / or derivative thereof)
As a 2nd wetting agent, the reduced form of a disaccharide and / or its derivative (s) can be mentioned. By using the first wetting agent and the second wetting agent, the water evaporation effect is greatly enhanced by the synergistic action of both water retention effects, and the increase in viscosity and solidification at the nozzle tip of the head are effective. Can prevent ink clogging (can improve clogging reliability). As a result, the present ink composition can ensure good ejection stability over a long period of time.

  The reduced form of disaccharide in the present invention is preferably a reduced form of disaccharide having glucose as a constituent sugar. Examples of the reduced form of disaccharide include lactitol, maltitol, cellobitole (reduced form of cellobiose), trehalitol (reduced form of trehalose) and the like. More preferred are lactitol and maltitol. More preferred is lactitol. The disaccharide reductant may be an anhydride or a hydrate. Examples of the derivative of the reduced form of disaccharide include a derivative in which one or a plurality of polyethylene oxide groups are introduced in place of one or a plurality of hydroxyl group hydrogen atoms. As the reduced form of disaccharide and / or a derivative thereof, one or a combination of two or more of these can be used. Although not intended to be bound by theory, it is considered that the wetting action or the clogging preventing action of the reduced form of disaccharide and / or its derivative is due to its structure. In these, half of the molecule is composed of a stiffer pyranosyl ring and the other half is composed of a softer acyclic polyhydric alcohol. It is speculated that the water is selectively bound to the pocket of the pyranosyl ring of the disaccharide reductant and held there by a flexible polyhydric alcohol arm.

  The first humectant such as 1,1,1-trimethylolpropane and the second humectant such as lactitol are preferably contained in an amount of 1% to 30% with respect to the entire ink composition. This is because if it is less than 1%, the effect of preventing clogging is insufficient, and if it exceeds 30%, the viscosity of the ink tends to increase. More preferably, it is 2% or more and 15% or less. The second wetting agent such as lactitol is preferably 5 parts or more and 2000 parts or less with respect to 100 parts of the first wetting agent. This is because if it is less than 5 parts, the clogging prevention effect is insufficient, and if it exceeds 2000 parts, the clogging prevention effect is insufficient. More preferably, the second wetting agent is 200 parts or more and 1100 parts or less with respect to 100 parts of the first wetting agent. While not intending to be bound by theory, the synergistic action of the first wetting agent such as 1,1,1-trimethylolpropane and the second wetting agent such as lactitol in the present invention is as follows: This is probably due to these structures as explained in As already mentioned, in the disaccharide reductant, half of the molecule is a stiffer pyranosyl ring and the other half is a softer acyclic polyhydric alcohol, which is 1,1,1-trimethyl. This is because half of the alkanol alkane is a hydrophobic alkane moiety and the other half is a hydrophilic polyhydric alcohol moiety. In the case where a disaccharide reductant and a trialkanol alkane are present, in addition to the previously mentioned binding of water to the disaccharide reductant, water is a polyvalent form of the disaccharide reductant and the trialkanol alkane. It appears to be selectively bound by the alcohol moiety. That is, among these, the more hydrophobic pyranosyl ring of the disaccharide reduced form retains the alkane portion of the trialkanol alkane, thereby providing two different hydrophilic properties derived from the disaccharide reduced form and the trialkanol alkane, respectively. It is presumed that the polyhydric alcohol portion of is arranged to retain water selectively by hydrogen bonding.

(Other wetting agents)
In the ink composition, in addition to the above-mentioned wetting agent, other wetting agents can be included as long as the object of the present invention is not hindered. Examples of other wetting agents include sugars, sugar alcohols (excluding the second wetting agent), hyaluronate, 1,2,6-hexanetriol, and the like. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol. (Sorbit), maltose, cellobiose, lactose, sucrose, trehalose, maltotriose and the like. The derivatives of these saccharides are represented by the reducing sugars of the saccharides described above (for example, sugar alcohol (general formula HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)). ), Oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thiosaccharides, etc.). As the hyaluronate, a commercially available sodium hyaluronate 1% aqueous solution (molecular weight 350,000) can be used.

(Organic solvent)
The ink composition contains various organic solvents in addition to water. For example, it is preferable to add the following water-soluble organic solvents that are water-soluble and have a water retention effect. Examples thereof include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol having a molecular weight of 2000 or less, propylene glycol, and dipropylene. Glycol, tripropylene glycol, 1,3-propylene glycol, isopropylene glycol, isobutylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, mesoerythritol And pentaerythritol. In the present invention, glycerin, triethylene glycol, diethylene glycol, and polyethylene glycol having a molecular weight of 2000 or less are particularly preferably used.

  In particular, the ink composition preferably contains glycerin, and in particular, improves the fluidity of the ink in the printer head. Glycerin is preferably contained within a range of 3% to 20% with respect to the total weight of the ink. If it is less than 3%, the fluidity of the ink in the printer head deteriorates. If it exceeds 20%, the viscosity of the ink tends to increase.

  In particular, the ink composition preferably contains triethylene glycol. Thereby, in particular, the fluidity of the ink in the printer head can be improved. Triethylene glycol is preferably contained in an amount of 3% to 20% with respect to the total amount of the ink composition. This is because if it is less than 3%, the fluidity of the re-ink in the printer head deteriorates, and if it exceeds 20%, the viscosity of the ink tends to increase.

  The ink composition preferably contains glycol ethers and 1,2-alkanediol, and when this is printed on a recording medium such as plain paper, inkjet recording paper, and inkjet recording sheet, Since the aqueous medium of the ink easily penetrates into the recording medium, the separation of the aqueous medium and the pigment-coated particles occurs in a short time, and the microencapsulated pigment of the present invention spreads along with the aqueous medium on the recording medium. Bleeding and print spots are reduced, and good print quality can be obtained.

  Examples of glycol ethers include diethylene glycol mono (C 1-8 alkyl) ether, triethylene glycol mono (C 1-8 alkyl) ether, propylene glycol mono (C 1-6 alkyl) ether, dipropylene. A glycol mono (C1-C6 alkyl) ether can be mentioned, These can be used as a 1 type, or 2 or more types of mixture.

  Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-iso-propyl ether, ethylene glycol monobutyl ether, ethylene glycol mono-t-butyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether (DEGmME) , Diethylene glycol monoethyl ether (DEGmEE), diethylene glycol monopropyl ether (DEGmPE), diethylene glycol mono-iso-propyl ether, diethylene glycol monobutyl ether (DEGmBE), diethylene glycol mono-t-butyl ether, diethylene glycol monopentyl ether (DEGmPeE), diethylene glycol Monohexyl ether (DEGmHE), diethylene glycol monoheptyl ether (DEGmHpE), diethylene glycol monooctyl ether (DEGmOE), triethylene glycol monomethyl ether (TEGmME), triethylene glycol monoethyl ether (TEGmEE), triethylene glycol monopropyl ether (TEGmPE), triethylene glycol monobutyl ether (TEGmBE), triethylene glycol monopentyl ether (TEGmPeE), triethylene glycol monohexyl ether (TEGmHE), triethylene glycol monoheptyl ether (TEGmHpE), triethylene glycol monooctyl ether (TRGmOE), propylene glycol Monomethyl ether (PGmME), propylene glycol monoethyl ether (PGmEE), propylene glycol monopropyl ether (PGmPE), propylene glycol mono-iso-propyl ether, propylene glycol monobutyl ether (PGmBE), propylene glycol mono-t-butyl ether, propylene Glycol monopentyl ether (PGmPeE), propylene glycol monohexyl ether (PGmHE), dipropylene glycol monomethyl ether (DPGmME), dipropylene glycol monoethyl ether (DPGmEE), dipropylene glycol monopropyl ether (DPGmPE), dipropylene glycol mono -Iso-propyl ether, dipropylene glycol mono Examples include butyl ether (DPGmBE), dipropylene glycol monopentyl ether (DPGmPeE), dipropylene glycol monohexyl ether (DPGmHE), etc., but the larger the alkyl group, the higher the hydrophobicity, so methyl, ethyl, propyl, butyl Is suitable for improving the printing quality on plain paper.

  In particular, the glycol ether is preferably diethylene glycol monobutyl ether or triethylene glycol monobutyl ether. It is preferable that diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether is contained in an amount of 0.5% to 10% with respect to the total amount of the ink composition. Good penetrability is exhibited within the above-mentioned content range. If it exceeds 10%, the viscosity tends to increase, such being undesirable.

  In addition, when the ink composition contains 0.5% by weight or more of one or more compounds selected from the group consisting of acetylene glycol surfactants and acetylene alcohol surfactants described later, the viewpoint of print quality Therefore, it is preferable that the weight ratio of the compound to diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether is more than 1: 0 and 1:10 or less. Di (tri) ethylene glycol monobutyl ether is useful for improving the solubility of acetylene glycol surfactants and improving print quality. However, when the addition amount exceeds 10 times, the effect tends to reach its peak. Because.

  The 1,2-alkanediol is preferably a 1,2-alkanediol having 4 to 10 carbon atoms. Two or more kinds of 1,2-alkanediols may be mixed and added. In a preferred embodiment of the present invention, examples of the 1,2-alkanediol include 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, and 1,2-heptanediol. These are more preferable from the viewpoint of excellent permeability to a recording medium. In a more preferred embodiment of the present invention, the 1,2-alkanediol is preferably 1,2-hexanediol or 1,2-pentanediol, more preferably 1,2-hexanediol.

  The 1,2-alkanediol is preferably contained in an amount of 20% or less based on the total amount of the ink composition. If it exceeds 20%, the improvement of the permeability will reach its peak, and not only the effect of improving the printing quality tends to be lowered, but also the adverse effect of an increase in viscosity tends to occur. More preferably, it is contained in the range of 0.5% to 15% with respect to the total amount of the ink composition. If it is 0.5% or more, sufficient penetrability can be obtained, and if it is 15% or less, it is easy to adjust the ink viscosity to be printable together with other additives, which is advantageous. More preferably, it is contained in the range of 1% to 5%.

  In the ink composition, 1,3-dimethyl-2-imidazolidine, N-methyl-2-pyrrolidone, 2-pyrrolidone, or the like is used as a dissolution aid. The dissolution aid is preferably used when using an acetylene alcohol surfactant described later. In particular, the dissolution aid such as 2-pyrrolidone for which 2-pyrrolidone is preferably used is preferably 0.5% or more and 10% or less with respect to the total amount of the ink composition. This is because if it is less than 0.5%, the effect of the dissolution aid is insufficient, and if it exceeds 10%, the viscosity of the ink tends to increase.

  In addition, as a component that improves the solubility of the ink component, further improves the permeability to a recording medium such as paper, or prevents clogging of the nozzle, it has 1 to 4 carbon atoms such as ethanol, methanol, butanol, propanol, isopropanol, and the like. Alkyl alcohols, formamide, acetamide, dimethyl sulfoxide, sorbit, sorbitan, acetin, diacetin, triacetin, sulfolane and the like, which can be appropriately selected and used.

(Dispersant)
In the case where the ink composition contains a pigment, the pigment may be dispersed in the ink composition coated with a resin, or may be dispersed by another polymer dispersant. It can be said that this form also takes the form of a pigment dispersion. Examples of the polymer dispersant include polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic ester copolymer, Acrylic resins such as acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene- Acrylic acid copolymer, styrene-acrylic resin such as styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-acrylic Acid copolymer, vinyl naphthalene-malein Acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic acid copolymer Mention may be made of vinyl acetate copolymers such as coalescence and salts thereof. Preferably, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic ester copolymer, acrylic acid-acrylic ester copolymer, etc. An acrylic resin is used. The amount of these dispersants added is preferably about 1 to 50% by weight, more preferably 2 to 30% by weight based on the pigment.

  The ink composition may contain polymer fine particles. Specific examples of the resin component constituting the polymer fine particles include acrylic resin, vinyl acetate resin, styrene-butadiene resin, vinyl chloride resin, acrylic-styrene resin, butadiene resin, styrene resin, silicone resin, urethane. Resin, polyester resin, polyamide resin, or a mixture thereof. These resins are not limited depending on the mode of polymerization and copolymerization, and may exist in the form of, for example, a block copolymer or a random copolymer. In particular, the polymer fine particles preferably include a resin mainly composed of an acrylic ester and / or a methacrylic ester. Particularly preferably, it comprises a resin mainly composed of an acrylic ester and / or a methacrylic ester and styrene.

  As the polymer fine particles, not only those having a single particle structure but also those having a core-shell structure comprising a core portion and a shell portion surrounding the core portion can be used. In the present invention, the “core-shell structure” means “a form in which two or more resins having different compositions are present in phase separation in the particles”. Therefore, the shell portion may not only cover the core portion completely, but may cover a portion of the core portion. Further, a part of the resin constituting the shell portion may form a domain or the like in the core particle. Further, it may have a multilayer structure of three or more layers including layers having different compositions in the middle between the core part and the shell part.

  The polymer fine particles can be obtained by known emulsion polymerization. That is, it can be obtained by emulsion polymerization of an unsaturated vinyl monomer (unsaturated vinyl monomer) in water containing a polymerization catalyst and an emulsifier. As unsaturated vinyl monomers, acrylic acid ester monomers, methacrylic acid ester monomers, aromatic vinyl monomers, vinyl ester monomers, vinyl, which are generally used in emulsion polymerization Examples include cyanide monomers, halogenated monomers, olefin monomers, and diene monomers. Further, specific examples include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, decyl acrylate, dodecyl acrylate. Acrylic acid esters such as octadecyl acrylate, cyclohexyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, glycidyl acrylate; methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hex Methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate, and other methacrylic acid esters; and vinyl acetate, such as vinyl acetate; acrylonitrile Vinyl cyanide compounds such as methacrylonitrile; halogenated monomers such as vinylidene chloride and vinyl chloride; aromatics such as styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene Group vinyl monomers; olefins such as ethylene, propylene and isopropylene; dienes such as butadiene and chloroprene; Ethers, vinyl ketones, vinyl monomers such as vinyl pyrrolidone. For monomers having no carboxyl group, it is essential to use unsaturated vinyl monomers having a carboxyl group, and preferred specific examples thereof include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid. Examples of the acid include methacrylic acid. Examples of emulsifiers that can be used include anionic surfactants, nonionic surfactants, and mixtures thereof. Particularly, in addition to sodium lauryl sulfate and potassium lauryl sulfate, anionic surfactants, nonionic surfactants and Amphoteric surfactants can be used, and surfactants that can be added to the inks described above can be used.

  Further, the polymer fine particles having a core-shell structure are produced by a known method, generally by multistage emulsion polymerization or the like. For example, it can be produced by the method disclosed in JP-A-4-76004. Specific examples of the unsaturated vinyl monomer used for the polymerization include those described above. In addition, as the polymer fine particles, those derived from a sulfonic acid group and / or a salt thereof in the resin structure are preferably used. Such polymer fine particles have a structure derived from a sulfonic acid group and / or a salt thereof and a structure crosslinked by a crosslinkable monomer (monomer) having two or more polymerizable double bonds. Is preferred. A structure derived from a sulfonic acid group and / or a salt thereof can be introduced by using a monomer having a sulfonic acid group as a copolymerization component. Specific examples of the monomer having a sulfonic acid group include vinyl sulfonic acid and its salt, styrene sulfonic acid and its salt, 2- (meth) acryloylamino-2-methylpropane sulfonic acid and its salt, sulfonated isoprene and the like. It is done.

  In addition, a polymerization initiator, a surfactant, a molecular weight adjusting agent, a neutralizing agent and the like used in the emulsion polymerization may be used according to a conventional method. As the polymerization initiator, a water-soluble polymerization initiator such as potassium persulfate or ammonium persulfate can be used. As the molecular weight modifier (chain transfer agent), in addition to t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, xanthogens such as dimethylxanthogen disulfide, diisobutylxanthogen disulfide, dipentene, indene, 1,4- Cyclohexadiene, dihydrofuran, xanthene and the like can be used.

  In addition, the dispersion of the pigment by these dispersants is performed by mixing a colorant, water, and a water-soluble organic solvent with a ball mill, sand mill, attritor, roll mill, agitator mill, Henschel mixer, colloid mill, ultrasonic homogenizer, jet mill, ang mill, etc. It is carried out with a suitable disperser.

(Surfactant)
The ink composition preferably contains a surfactant, particularly an anionic surfactant and / or a nonionic surfactant. Specific examples of anionic surfactants include alkane sulfonate, α-olefin sulfonate, alkylbenzene sulfonate, alkyl naphthalene sulfonic acid, acylmethyl tauric acid, dialkyl sulfosuccinic acid and other sulfonic acid types, alkyl sulfuric acid Ester salt, sulfated oil, sulfated olefin, polyoxyethylene alkyl ether sulfate ester salt; carboxylic acid type such as fatty acid salt, alkyl sarcosine salt; alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester mono And phosphoric acid ester type such as glycerite phosphoric acid ester salt. Specific examples of nonionic surfactants include ethylene oxide addition types such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amide; glycerin alkyl ester, sorbitan alkyl ester Polyol ester type such as sugar alkyl ester; polyether type such as polyhydric alcohol alkyl ether; alkanolamide type such as alkanolamine fatty acid amide.

The ink composition preferably contains at least one surfactant selected from the group consisting of acetylene glycol surfactants and acetylene alcohol surfactants. When printing on a recording medium such as an inkjet recording sheet, the aqueous medium of ink easily penetrates into the inside of the recording medium, so that the separation of the aqueous medium and the microencapsulated pigment of the present invention occurs in a short time, and the recording medium Since the microencapsulated pigment of the present invention does not spread together with the aqueous medium and bleeding and print spots are reduced, good print quality can be obtained. When using an acetylene glycol surfactant and an acetylene alcohol surfactant, it is particularly preferable to use them in combination with the above-mentioned glycol ethers. For example, an acetylene glycol compound represented by the following general formula (2) can be used.

In the above formula (2), m and n are numbers satisfying 0 ≦ m + n ≦ 50, respectively. R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group (preferably an alkyl group having 6 or less carbon atoms). Among the compounds represented by the formula (2), 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3, 6-diol, 3,5-dimethyl-1-hexyn-3-ol and the like. As the compound represented by the above formula (2), it is also possible to use a commercially available product that is commercially available as an acetylene glycol surfactant. Specific examples thereof include Surfynol 104, 82, 440, 465, 485 or STG (all available from Air Products and Chemicals. Inc.), Orphine STG, Olphine E1010 (above, Nissin Chemical Co., Ltd., trade name).

  Acetylene alcohol-based surfactants can also be used, and specific examples include Olfine P, Olfine B (Nisshin Chemical), and Surfynol 61 (Air Products). When using the acetylene alcohol surfactant, a solubilizer can also be used. As the solubilizing agent, dimethyl-2-imidazolidinone, 2-pyrrolidone and N-methyl-2-pyrrolidone are preferable. Polysiloxane surfactants can also be used, and preferred specific examples thereof include BYK-301, 302, 307, 325, 331, 341, 345, 346, 348, and 375 (manufactured by Big Chemie).

  The content of these surfactants is preferably in the range of 0.01% to 10%, more preferably 0.1% to 5%, and still more preferably 0% with respect to the total amount of the ink composition. .1% to 2%.

  In addition, it is possible to add another surfactant to the ink composition in order to control the permeability to the recording medium. The surfactant to be added is preferably a surfactant having good compatibility with the ink of the present invention, and among the surfactants, those having high permeability and stability are preferable. Examples thereof include amphoteric surfactants and nonionic surfactants. Amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine and other imidazoline derivatives. is there. Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene Ethers such as ethylene alkyl ether and polyoxyalkylene alkyl ether, polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquis Esters such as oleate, polyoxyethylene monooleate, polyoxyethylene stearate, etc. Alkyl esters, and the like fluorine-containing surfactants such as perfluoroalkyl carboxylates.

  In addition, pH adjusters, amines such as diethanolamine, triethanolamine, propanolamine, morpholine and their modified products, inorganic hydroxides such as potassium hydroxide, sodium hydroxide, lithium hydroxide, ammonium hydroxide, quaternary Examples thereof include ammonium salts (such as tetramethylammonium), carbonates such as potassium carbonate, sodium carbonate, and lithium carbonate, and phosphates.

  Other additives include ureas such as urea, thiourea and tetramethylurea, allophanates such as allophanate and methylallohanate, biurets such as biuret, dimethylbiuret and tetramethylbiuret, and L-ascorbic acid and its salts Commercially available antioxidants, ultraviolet absorbers and the like can also be used.

  The ink composition preferably has a surface tension of 45 mN / m or less, more preferably in the range of 20 to 45 mN / m. When the surface tension exceeds 45 mN / m, it is difficult to obtain a good printed image due to poor print drying, easy bleeding, and color bleeding. Further, when the surface tension is less than 20 mN / m, the periphery of the nozzles of the printer head is likely to get wet, so that the ink droplets are likely to be bent and the ejection stability is likely to occur. The surface tension can be measured with a commonly used surface tension meter. The surface tension of the ink can be set within the above range by adjusting the type and composition ratio of each component constituting the ink.

  From the above, the present ink composition can be preferably used in a recording apparatus using an ink jet recording method. When used as an ink composition for ink jet recording, it is possible to improve the clogging reliability in the nozzles of the printer head and maintain good ejection stability. Further, the maintenance work of the head can be omitted.

  The inkjet recording method of the present invention is a recording method in which ink droplets are ejected, and the droplets are attached to a recording medium for printing, and is characterized by using the ink composition of the present invention. Here, the recording method is an ink cartridge containing the ink jet recording ink of the present invention (in the case of an ink set comprising a plurality of ink jet recording inks, each ink jet recording ink is individually contained. The ink cartridge is mounted on a known ink jet recording apparatus, and printing is performed on the recording medium. Here, as the ink jet recording apparatus, an electrostrictive element that can vibrate based on an electric signal is mounted, and the ink for ink jet recording according to the present invention is applied by the vibration of the electrostrictive element, or according to the present invention. An ink jet recording apparatus configured to be able to discharge ink included in the ink set can be preferably exemplified.

  According to the ink composition and the recording method, a high-quality image can be obtained as a result of excellent discharge stability. At the same time, maintenance of the nozzle portion of the printer head in the ink jet recording apparatus can be simplified. The recorded matter of the present invention is provided with a high-quality image.

  Examples of the present invention will be specifically described below. In addition, these Examples are for demonstrating this invention, and do not limit this invention.

(1) Preparation of dispersion M [Synthesis of dispersion resin]
A reaction vessel equipped with a stirrer, thermometer, reflux tube and dropping funnel was replaced with nitrogen, and then 25 g of styrene, 30 g of n-dodecyl methacrylate, 20 g of methoxypolyethylene glycol methacrylate, 16 g of butyl methacrylate, and 9.5 g of methacrylic acid were dissolved in 100 g of methyl ethyl ketone. Then, nitrogen gas replacement was performed. The same monomer / methyl ethyl ketone solution was placed in the dropping funnel, and 0.2 g of 2,2′-azobis (2,4-isomethylvaleronitrile) was further added to perform nitrogen gas replacement. In a nitrogen atmosphere, the polymerization reaction was carried out while heating to 65 ° C. and adding the dropping funnel solution over 3 hours. The obtained copolymer solution was purified by repeatedly drying under reduced pressure, dissolving methyl ethyl ketone and filtering, and then diluted by adding methyl ethyl ketone so that the solid content of the resin was 50% by weight. A resin solution A having an acid value of about 70 KOH mg / g and an average molecular weight of 50,000 was obtained.

[Preparation of dispersion]
The pigment is an organic pigment C.I. I. PigmentRed122200g and the above-mentioned resin solution A100g were mixed and stirred, and the slurry was produced. To this slurry, 38 g of a 10% aqueous potassium hydroxide solution was added and dispersed with an ultrahigh pressure homogenizer. Subsequently, this dispersion solution is gradually added to 400 g of stirring pure water, and further, all of methyl ethyl ketone and a part of water are removed under reduced pressure at 60 ° C., so that the pigment concentration becomes 15%. Pure water was added to obtain a dispersion M.

(Preparation of dispersion Y)
For the dispersion M, the pigment is an organic pigment C.I. I. Pigment Yellow 74 was changed to 150 g, and a dispersion was prepared in the same manner except that the amount of 10% potassium hydroxide aqueous solution was changed to 39 g. This was designated as dispersion Y.

(3) Dispersion C
For the dispersion M, the pigment is an organic pigment C.I. I. Pigment Blue 15: 4 was changed to 50 g, and a dispersion was prepared in the same manner except that the amount of 10% potassium hydroxide aqueous solution was changed to 40 g. This was designated as Dispersion C.

(4) Dispersion K
The black ink dispersion was prepared in accordance with the method described in Example 2 of International Publication (WO / 94476). FW-18 carbon black (manufactured by Degussa) was used as the black pigment. Ozone was generated by an ozone generator (made by PCI Ozone), and a high shear force was applied to the colorant simultaneously with ozone oxidation using an M-110EH type microfluidizer (made by MFIC). The resulting dispersion of the self-dispersing pigment was purified by ultrafiltration using a pericon laboratory system (Millipore). Finally, a dispersion having a pigment concentration of 15% was obtained. This was designated as Dispersion Liquid K. The average particle diameter of the pigment particles in the dispersion was 98 nm (UPA150 particle analyzer, manufactured by Honeywell Microtrac ™).

(Preparation of water-based ink)
37.4 g of the dispersion M obtained by the above-mentioned materials and methods, 0.4 g of Surfynol 104PG-50 as acetylene glycol and Surfynol 465 (both of the above two are trade names, manufactured by Air Products and Chemicals, Inc.). 0.1 g, 1 g of trimethylolpropane, 1 g of lactitol, 14 g of glycerol as an organic solvent, 4 g of 2-pyrrolidone, 2 g of triethylene glycol, 1 g of triethylene glycol monobutyl ether, 2. 5 g, and ultrapure water was further added to make the total amount 100 g. The mixture was stirred for 2 hours and filtered through a membrane filter (trade name, manufactured by Nihon Millipore Limited) having a pore size of about 1.2 μm to prepare the aqueous ink composition of Example 1. did. In addition, the composition of Examples 1-11 is collectively shown in FIG.

(Examples 2 to 11)
The aqueous ink compositions of Examples 2 to 11 were prepared in the same manner as in Example 1 except that the composition was changed to the composition shown in FIG.

(Comparative Examples 1-15)
A water-based ink composition of Comparative Examples 1 to 15 was prepared in the same manner as in Example 1 except that the composition was changed to the composition shown in FIG. The compositions of Comparative Examples 1 to 15 are shown together in FIG.

(Evaluation of ink composition)
(Discharge stability and gloss of special paper printing)
The aqueous ink compositions of Examples 1 to 11 and Comparative Examples 1 to 15 were mounted on PX-V700 (trade name, manufactured by Seiko Epson Corporation) which is an inkjet printer. Images with mixed characters and fills in an environment of 25 ° C / 40% RH are continuously printed on paper (Xerox 4024), and every 100 sheets are checked for defects such as bent or missing flight. Evaluation was made visually. As a result of printing 1000 sheets, no flying curve, nozzle clogging, or a decrease in glossiness was observed for all ink compositions. From these results, it was found that all the ink compositions had sufficient ejection stability and exclusive paper printing gloss.

(Storage stability)
The aqueous ink compositions of Examples 1 to 11 and Comparative Examples 1 to 15 were left at 60 ° C. for 2 weeks, left for 1 month, and left for 1 week in a frozen state, and the viscosity immediately after ink preparation was compared with the value after being left. . Judgment criteria are as follows.
Judgment A: Fluctuation width is less than ± 6% B: Fluctuation width is ± 6% or more and less than ± 10% C: Fluctuation width is ± 10% or more Digital Viscomate VM-100A (Yamaichi Electric Co., Ltd.) The viscosity was measured at 20 ° C.

    For all ink compositions, A level storage stability was obtained. From these results, it was found that all the ink compositions had sufficient storage stability.

(Clogging reliability)
Using the water-based ink compositions of Examples 1 to 11 and Comparative Examples 1 to 15, clogging reliability was evaluated as follows. First, all the inks were degassed and sealed in a heat-sealable aluminum package. Next, each ink composition was attached to a stylus C80 printer (trade name, manufactured by Seiko Epson Corporation) which is an inkjet printer. A line pattern using all nozzles was first printed so that the ink composition was ejected from all nozzles with good directionality. Next, the ink cartridge was removed from the printer head, and the printer head was also removed from the printer. The uncapped printer head was left in a constant temperature apparatus at 40 ° C. for 4 days. Thereafter, the printer head was mounted on the printer, and the ink cartridge was mounted on the printer head. Then, after printing the line pattern using all the nozzles, a cleaning operation was performed. The line pattern printing after cleaning was repeated until all the nozzles could print with good orientation. The judgment criteria were as follows.
Criteria A: Normal printing can be performed simultaneously with sending a print signal to the printer without performing a cleaning operation.
B: Normal printing can be performed within two cleaning operations.
C: Normal printing can be performed within 4 cleaning operations.
D: Normal printing can be performed within 6 cleaning operations.
F: Even if the cleaning operation is repeated seven times or more, normal printing cannot be performed.
(When evaluation is A and B, it can be said that it has clogging reliability.) The evaluation result of an Example and a comparative example is put together in FIG.

    As shown in FIG. 3, the evaluation about Examples 1-11 was A and B, and had sufficient clogging reliability. In particular, the amount of disaccharide reductant with respect to the total amount of trialkanol alkane and disaccharide reductant has high reliability in a wide range of 5% to 95%, and these total amount is the total amount of the ink composition. On the other hand, it was found to be excellent in the range of 1% to 2%. As described above, extremely good clogging reliability could be secured by the combination of trialkanol alkane and disaccharide reductant.

It is a figure which shows the composition of the ink compositions 1-11 of an Example. It is a figure which shows the composition of the ink compositions 1-15 of a comparative example. It is a figure which shows the result of the clogging reliability of the ink composition of an Example and a comparative example.

Claims (9)

An aqueous ink composition comprising:
A coloring material,
water and,
An organic solvent,
A compound represented by the following general formula (1):

(In the above formula, m and n each represent an integer of 1 to 5.)
A disaccharide reductant and / or a derivative thereof;
A composition comprising:   The composition according to claim 1, wherein the colorant is one or more selected from a dye and a pigment dispersion.   The composition according to claim 1 or 2, wherein the reduced form of the disaccharide is one or more selected from the group consisting of lactitol, hydrates thereof, maltitol, and hydrates thereof.   The composition according to any one of claims 1 to 3, wherein the compound represented by the general formula (1) is 1,1,1-trimethylolpropane.   The total amount of the compound represented by the general formula (1) and the reduced form of the disaccharide and / or a derivative thereof is 1 wt% or more and 30 wt% or less with respect to the total amount of the ink composition. 5. The composition according to any one of 4.   The reductant of the disaccharide and / or a derivative thereof is contained in an amount of 5 parts by weight or more and 2000 parts by weight or less based on 100 parts by weight of the compound represented by the general formula (1). Composition.   The composition according to claim 1, which is for an ink jet recording apparatus. An ink jet recording method comprising:
Applying the water-based ink composition according to claim 1 to a recording medium surface by an ink jet recording method;
A method comprising: An inkjet recording,
A recorded matter having a dot pattern by an ink jet recording method comprising the aqueous ink composition according to claim 1 on the surface of a recording medium.

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