JP2013107952A - Water-based pigment ink for inkjet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-based pigment ink for inkjet, excellent in storage stability and capable of obtaining a high-quality image having no white stripes, color unevenness and intercolor bleeding on a highly hydrophobic paper such as a general printing paper, particularly a coated paper or art paper.SOLUTION: The water-based pigment ink for inkjet contains a pigment, pigment-dispersing resin, water, water-soluble solvent and fluorine-based surfactant. The fluorine-based surfactant is a compound represented by a specified structural formula. Further, the pigment ink for inkjet is used in combination with a nonionic surfactant represented by a specified structural formula.

Description

  The present invention provides a water-based inkjet which is capable of obtaining a high-quality image free of white streaks, color unevenness, and intercolor bleeding on general printing paper, particularly coated paper, art paper, and the like, and has excellent storage stability. The present invention relates to a pigment ink.

  The ink jet recording method is a recording method in which characters and images are obtained by ejecting ink droplets directly from a very fine nozzle onto a recording member and attaching them. According to this method, there is an advantage that not only the noise of the apparatus to be used is small and the operability is good, but also colorization is easy and plain paper can be used as a recording member. It is widely used as an output machine in offices and homes.

  On the other hand, in industrial applications, use as an output device for digital printing is expected due to improvements in inkjet technology, and water-based pigment inks are demanded from the viewpoint of environment and cost.

In aqueous pigment ink, since the pigment is insoluble in water, in order to keep the pigment dispersed in the ink, the dispersion is stabilized by using a dispersion resin. (For example, see Patent Documents 1, 2, and 3).
In the case of an ink jet recording system, a high-boiling water-soluble solvent that is positioned as a humectant is included for the purpose of preventing the nozzle from drying.

  General printing paper is coated paper with a coating layer for receiving oil-based ink on its surface, but the coating layer is hydrophobic, so the wettability and absorption capacity of aqueous ink are poor. Has characteristics. Therefore, when an aqueous pigment ink generally used for ink jet recording is used, there are problems such as low wettability and penetrability of the ink and white streaks and blurring in the image.

  For this reason, by using a surfactant in the ink, the surface tension can be lowered and wettability and permeability can be improved. Examples of the surfactant include polyoxyethylene alkyl ether surfactants, polyoxyethylene alkyl phenyl ether surfactants, silicon surfactants, and fluorine surfactants. Among these, it is known that a fluorine-based surfactant exhibits a surface tension lowering ability superior to that of an alkyl ether-based surfactant or a silicon-based surfactant having the same structure.

  As the fluorosurfactant, perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) or a fluorosurfactant based on them is widely used. PFOS has a structure in which a sulfonyl group is directly connected to a perfluoroalkyl group, and PFOA has a structure in which a carboxy group is directly connected to a perfluoroalkyl group. Conventionally, those having a perfluoroalkyl group having a chain length of 8 or more are preferably used because of their high performance.

  However, since PFOS and PFOA are extremely difficult to be decomposed and have high bioaccumulation potential, there is a concern about environmental pollution on a global scale in recent years. In this PFOS / PFOA problem, a compound having a perfluoroalkyl group with a chain length of 8 or more is regarded as a problem, and there are laws and regulations in each country and voluntary regulations by each company, and a perfluoroalkyl group with a chain length of 8 or more. It is becoming difficult to obtain and use compounds having the following.

  As a method for solving the PFOS / PFOA problem, there is a method using a compound having a perfluoroalkyl group having a chain length shorter than 8 as a fluorine-based surfactant. However, the reason why perfluoroalkyl groups having a chain length of 8 or more were favorably used is because of their high leveling and wettability enhancement capabilities. When the chain length of perfluoroalkyl groups is short, the wettability and leveling are extremely high. There was a problem that the property became low.

JP 2004-181955 A JP 2004-181955 A JP 2007-238813 A JP 2010-275377 A

  The present invention provides a water-based inkjet which is capable of obtaining a high-quality image free of white streaks, color unevenness, and intercolor bleeding on general printing paper, particularly coated paper, art paper, and the like, and has excellent storage stability. It is an object of the present invention to provide a pigment ink for use.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by the following water-based inkjet pigment ink, and have completed the present invention. That is, the present invention relates to an inkjet pigment ink comprising a pigment, a pigment dispersion resin, water, a water-soluble solvent, and a fluorosurfactant, wherein the fluorosurfactant is represented by the following general formula (I). The present invention relates to an inkjet pigment ink which is a compound to be used.

(Wherein Rf is a perfluoroalkyl group having 1 to 6 carbon atoms, X is COO, SO ₃ , SO ₄ , PO ₄ , Y is NH ₄ , N (C ₂ H ₅ ) ₃ , N (C ₂ H ₅ OH) ₃ , Li, Na, K are represented, and m and n represent an integer of 1-6.)
In the invention, the fluorosurfactant is 0.05 to 1% by weight based on the ink composition. The invention also contains a nonionic surfactant represented by the following general formula (II). The present invention relates to the inkjet pigment ink.

(In formula, p and q represent the integer of 0-40.)

The present invention also relates to the above-described ink-jet pigment ink containing an amino alcohol.
The present invention also relates to the above-described ink-jet pigment ink containing water-dispersible resin fine particles.
The present invention also relates to the above-described inkjet pigment ink containing a water-dispersible wax.

Furthermore, this invention relates to the printed matter which printed the said pigment ink for inkjets on printing paper.
Furthermore, the present invention provides printing on printing paper in which an ink receiving layer made of a water-soluble resin having a carboxyl group and / or a sulfonic acid group and / or a water-dispersible resin having a carboxyl group and / or a sulfonic acid group is coated on the printing paper. Related to printed materials.

  According to the present invention, it is possible to obtain a high-quality image free of white streaks, color unevenness, and intercolor bleeding on general printing paper, particularly coated paper, art paper, and the like, and has excellent storage stability. An aqueous inkjet pigment ink can be provided.

  First, because of the ink of the present invention, it is possible to obtain a high-quality image free from white streaks, color unevenness, and intercolor bleeding on general printing paper, particularly coated paper, art paper, and other highly hydrophobic paper. Explain whether it is superior.

In order to obtain a high-quality image in ink jet printing, it is important that ink ejected from the nozzles form ink dots on the printing paper by appropriately spreading and drying in a short time. Ink-jet inks cannot discharge ink when the nozzles are dried, so a humectant, that is, a high-boiling water-soluble solvent is essential. However, when it contains a high-boiling water-soluble solvent, it can be applied to coated paper (paper coated about 20 g / m ^{2 on} one side) and art paper (paper coated about 40 g / m ^{2 on} one side), which are general printing paper. When printing, the wettability and penetrability are poor, and this may cause white streaks and color unevenness that are caused by the connection between the printed dots.

  Therefore, it is important to improve the drying property by using a surfactant that improves wettability and permeability to paper. The compound represented by the general formula (I) is the surfactant. In the study by the present inventors, the fluorosurfactant represented by the general formula (I) adjusted the static surface tension in the same manner as compared with the commonly used fluorosurfactants, silicon-based hydrocarbons, and hydrocarbon-based surfactants. It was confirmed that the ink has high permeability and wettability to hydrophobic-coated printing paper. The exact principle is unknown, but the following can be inferred. In general, fluorosurfactants are oriented at the gas-liquid interface to lower the liquid interfacial tension and improve wettability to hydrophobic substrates. However, since the penetrating power to the substrate is insufficient, dots do not fix. Unevenness occurs.

  Since the fluorosurfactant represented by the general formula (I) has an anionic group as a water-soluble component, it has higher hydrophilicity than a nonionic group such as ethylene oxide. Further, since it has a hydroxyl group in the vicinity of the perfluoroalkyl group, it is considered that the permeability of the ink can be enhanced by effectively orienting the hydrophobic substrate surface in the aqueous ink. Furthermore, the effect of lowering the dynamic surface tension of ink, particularly the surface tension in a short life time of 10 ms or less, is large, and it becomes possible to eliminate beading (white streaks in which dots are connected to each other). In other words, by using the fluorine-based surfactant represented by the general formula (I), white streaks, color unevenness, and inter-color between general printing paper, especially coated paper, art paper, and other highly hydrophobic paper A high-quality image without bleeding can be obtained, and an ink excellent in storage stability can be obtained.

  The water-based inkjet pigment ink of the present invention (hereinafter referred to as water-based pigment ink or ink) will be described below with reference to preferred embodiments.

The fluorine-based surfactant represented by the general formula (I) used in the present invention is used for the purpose of lowering the dynamic surface tension of the aqueous pigment ink and improving the wettability and permeability to the printing paper. The
In the fluorine-based surfactant represented by the general formula (I) of the present invention, Rf is a C 1-6 perfluoroalkyl group. The perfluoroalkyl group may be linear or branched, but is preferably linear. Rf is preferably a linear perfluoroalkyl group having 4 to 6 carbon atoms because of its ability to reduce surface tension and good permeability to hydrophobic substrates. The group is particularly preferred.

  In the fluorine-based surfactant represented by the general formula (I) of the present invention, m and n are integers of 1 to 6. The alkylene group determined by the number of carbon atoms m and n may be linear or branched, but is preferably linear. Among these, a linear alkylene group having 1 to 3 carbon atoms is preferable, m is a linear chain having 1 to 2 carbon atoms, and n is more preferably a linear chain having 2 to 3 carbon atoms.

In the fluorine-based surfactant represented by the general formula (I) of the present invention, X represents an anionic group, and examples thereof include COO, SO ₃ , SO ₄ , PO ₄ , etc. Among these, COO is particularly preferable. Y represents a cationic group, and examples thereof include NH ₄ , N (C ₂ H ₅ ) ₃ , N (C ₂ H ₅ OH) ₃ , Li, Na, K, etc. Among these, NH 4 is particularly preferable.

Particularly preferred as the fluorosurfactant represented by the general formula (I) of the present invention is as follows.
_{C 6 F 13 -CH 2 CH (} OH) CH 2 S (CH 2) 2 COONH 4
_{C 6 F 13 -CH 2 CH (} OH) CH 2 S (CH 2) 3 COONH 4
_{C 6 F 13 -CH 2 CH (} OH) CH 2 S (CH 2) 2 SO 3 Na
_{C 6 F 13 -CH 2 CH (} OH) CH 2 S (CH 2) 3 SO 3 Na
_{C 6 F 13 - (CH 2} ) 2 CH (OH) CH 2 S (CH 2) 2 COONH 4
_{C 6 F 13 - (CH 2} ) 2 CH (OH) CH 2 S (CH 2) 3 COONH 4
_{C 6 F 13 - (CH 2} ) 2 CH (OH) CH 2 S (CH 2) 2 SO 3 Na
_{C 6 F 13 - (CH 2} ) 2 CH (OH) CH 2 S (CH 2) 3 SO 3 Na
_{C 4 F 9 -CH 2 CH (} OH) CH 2 S (CH 2) 2 COONH 4
_{C 4 F 9 -CH 2 CH (} OH) CH 2 S (CH 2) 3 COONH 4
_{C 4 F 9 -CH 2 CH (} OH) CH 2 S (CH 2) 2 SO 3 Na
_{C 4 F 9 -CH 2 CH (} OH) CH 2 S (CH 2) 3 SO 3 Na

  In the present invention, the content of the fluorosurfactant represented by the general formula (I) is preferably 0.05 to 1% by weight, and preferably 0.1 to 0.5% by weight with respect to the entire ink composition. Is more preferable. If it is less than 0.05% by weight, the ink wettability and penetrability will be insufficient, and when printing on printing paper, the ink dots will not spread sufficiently, which may cause problems such as white streaks and color unevenness. is there. On the other hand, if it exceeds 1% by weight, the storage stability of the ink with time may be insufficient, which may be a problem.

  The aqueous pigment ink of the present invention comprises at least a pigment, a water-soluble solvent, and water in addition to the fluorine-based surfactant represented by the general formula (I) defined in the present invention described above. Hereinafter, each of these components will be described.

As the pigment contained in the aqueous pigment ink of the present invention, conventionally known pigments can be used.
Examples of the black pigment that can be used in the present invention include carbon black produced by a furnace method or a channel method. For example, these carbon blacks have a primary particle diameter of 11 to 40 mμm (nm), a specific surface area by the BET method of 50 to 400 m ² / g, a volatile content of 0.5 to 10% by mass, and a pH value of 2 to 2. Those having characteristics such as 10 are preferred. The following are mentioned as a commercial item which has such a characteristic. For example,
No. 33, 40, 45, 52, 900, 2200B, 2300, MA7, MA8, MCF88 (manufactured by Mitsubishi Chemical), RAVEN1255 (manufactured by Colombia), REGAL330R, 400R, 660R, MOGULL (manufactured by Cabot), Nipex 160IQ, There are Nipex 170IQ, Nipex 75, Printex 85, Printex 95, Printex 90, Printex 35, Printex U (manufactured by Degussa), and any of them can be preferably used.

As a yellow pigment that can be used in the present invention, for example,
C. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 55, 74, 81, 83, 109, 113, 128, 150, 151, 155, 183, and the like.

Examples of magenta pigments that can be used in the present invention include:
C. I. Pigment Red 5, 7, 12, 22, 23, 31, 48 (Ca), 48 (Mn), 49, 52, 53, 57 (Ca), 57: 1, 112, 122; quinacridone solid solution, 146, 147, 150 238, 269, C.I. I. PigmentViolet 19 etc. are mentioned.

Examples of cyan pigments that can be used in the present invention include:
C. I. Pigment Blue 1, 2, 3, 15: 3, 15: 4, 16, 22, C.I. I. VatBlue 4, 6 etc. are mentioned.

  As the pigment that can be used in the present invention, pigments of colors other than those described above, self-dispersing pigments, and the like can also be used. These pigments can be used alone or in combination of two or more in each color ink.

  The content of the pigment that can be used in the present invention is in the range of 1 to 20% by weight, more preferably 2 to 12% by weight in the aqueous pigment ink.

  As the pigment dispersion resin contained in the aqueous pigment ink of the present invention, conventionally known ones can be used, but (meth) acrylic acid copolymers are generally used. This is because charge repulsion occurs between pigments in an aqueous solvent due to charge repulsion when the (meth) acrylic acid copolymer adsorbed on the pigment surface is ionized, and a stable pigment dispersion state can be maintained. Conceivable.

  As water contained in the water-based pigment ink of the present invention, it is preferable to use ion-exchanged water (deionized water) instead of general water containing various ions.

  The water content that can be used in the present invention is 10 to 90% by weight, more preferably 30 to 80% by weight, based on the total weight of the ink.

As the water-soluble solvent contained in the aqueous pigment ink of the present invention, conventionally known solvents can be used.
As the water-soluble solvent that can be used in the present invention, from the viewpoint of moisture retention, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1 , 4-butanediol, 2,3-butanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 2,3-hexanediol, 2, Examples include 4-hexanediol, diethylene glycol, triethylene glycol, and tetraethylene glycol. In addition, from the viewpoint of wettability to printing paper, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol mono 2-ethylhexyl ether, diethylene glycol monomethyl Ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol mono 2-ethylhexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethyl Lenglycol monobutyl ether, triethylene glycol monohexyl ether, triethylene glycol mono 2-ethylhexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, di Examples include propylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, and tripropylene glycol monobutyl ether. These water-soluble solvents can be used alone or in combination of two or more in each color ink.

  The content of the water-soluble organic solvent that can be used in the present invention is generally in the range of 3 to 60% by weight, more preferably in the range of 3 to 50% by weight, based on the total weight of the ink.

  Furthermore, the ink of the present invention preferably contains a nonionic surfactant represented by the general formula (II). By containing the nonionic surfactant represented by the general formula (II), the dynamic surface tension of the aqueous pigment ink can be reduced, and the wettability and penetrability to the printing paper can be improved. This improves the image quality. In the nonionic surfactant represented by the general formula (II) of the present invention, p and q are integers of 0 to 40.

  Examples of commercially available nonionic surfactants represented by the general formula (II) that can be used in the present invention include Air Products and Chemicals Inc. Surfynol 104, 420, 440, 465, 485 manufactured by Kawaken Fine Chemical Co., Ltd., acetylenol E40, E81, E100, E200, Orshin E1004, E1010 manufactured by Nissin Chemical Industry Co., Ltd. may be mentioned.

  The content of the nonionic surfactant represented by the general formula (II) as described above is in the range of 0.1 to 2% by weight, more preferably 0.3% with respect to the entire ink composition. It is in the range of ˜1% by weight.

  Furthermore, the ink of the present invention preferably contains an amino alcohol. By containing the amino alcohol, the amino alcohol selectively swells the coating layer with respect to the printing paper coated with the resin to accept the oil-based ink, and the permeability of the aqueous pigment ink can be improved. This improves the image quality.

Specific examples of amino alcohol include, for example, monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, monomethylethanolamine, dimethylethanolamine, monoethylethanolamine, and diethylethanolamine. These can be used alone or in combination of two or more.
Among these, if the boiling point of amino alcohol is too high, the water resistance of the printed matter may become a problem. Use dimethylethanolamine, diethylethanolamine, or monomethylethanolamine with an appropriate boiling point that does not affect the ejection properties. Is more preferable.

  The content of amino alcohol as described above is preferably 0.1 to 2% by weight, and more preferably 0.2 to 1% by weight, based on the entire ink composition. If it exceeds 2% by weight, ejection failure due to an increase in ink viscosity may be a problem.

  Furthermore, the ink of the present invention preferably contains water-dispersible resin fine particles. By containing the water dispersible resin fine particles, the viscosity of the coated film can be improved without increasing the viscosity. Thereby, water resistance, solvent resistance, scratch resistance and the like are improved. Even if a water-soluble resin is added, the resistance can be expected to improve to some extent, but the viscosity tends to increase. In the case of inkjet ink, there is a certain range in the viscosity at which ink can be ejected from the nozzles, and if the viscosity is too high, it may not be possible to eject ink, so it is important to suppress an increase in viscosity.

  The content of the water-dispersible resin fine particles as described above in the ink is a solid content in the range of 2 to 20% by mass, and more preferably in the range of 3 to 15% by mass with respect to the total weight of the ink.

  Furthermore, the ink of the present invention preferably contains a water-dispersible wax. By containing the water dispersible wax, the resistance of the printed coating film can be improved without increasing the viscosity. Thereby, abrasion resistance improves.

  Examples of the water-dispersible wax that can be used in the present invention include water dispersions of natural wax and synthetic wax. Natural waxes include petroleum waxes such as paraffin wax, microcrystalline wax, and petrolatum, or plant waxes such as carnauba wax, candelilla wax, rice wax, and wood wax, and also animal plant waxes such as lanolin, A beeswax can be mentioned. Examples of synthetic waxes include synthetic hydrocarbon waxes such as polyethylene wax, polypropylene wax, and Fischer-Tropsch wax, or modified waxes such as paraffin wax derivatives, montan wax derivatives, and microcrystalline wax derivatives. . These water-dispersible waxes can be used alone or in combination of two or more in each color ink. Commercially available water-dispersible waxes include, for example, AF-41, AG-73 (HDPE), A-514 (LDPE), A-329, A-206 (microcrystalline), AD manufactured by Gifu Seratech Manufacturing Co., Ltd. -62 (paraffin), X-8512 (lanolin), XA-35 (amide resin), AF-20 (beeswax), XD-075 (carnauba), AQUACER 515, 531, 537, 539 (PE) manufactured by BYK Japan ), AQUACER 593 (PP).

  The content of the water-dispersible wax as described above in the ink is a solid content in the range of 0.2 to 5% by weight of the total weight of the ink, and more preferably in the range of 0.3 to 2% by weight. It is.

  In addition to the above-described components, the ink of the present invention may be appropriately added with additives such as a surface conditioner, an antifoaming agent, and an antiseptic agent in order to obtain an ink having a desired physical property value as necessary. be able to. Examples of the amount of these additives added are in the range of 0.05 to 10% by weight, preferably in the range of 0.2 to 5% by weight, based on the total weight of the ink.

  Examples of the method for producing the ink of the present invention comprising the above-described components include the following methods, but the present invention is not limited thereto. First, a pigment is added to an aqueous medium in which at least a pigment dispersion resin and water are mixed, and after mixing and stirring, dispersion processing is performed using a dispersion means described later, and centrifugation is performed as necessary. To obtain a desired pigment dispersion. Next, if necessary, a water-soluble solvent or an appropriately selected additive component as mentioned above is added to the pigment dispersion, followed by stirring, and if necessary, filtering to obtain the ink of the present invention. To do.

  In the ink production method of the present invention, as described above, a pigment dispersion obtained by carrying out a dispersion treatment is used for the preparation of the ink, but before the dispersion treatment carried out during the preparation of the pigment dispersion. It is effective to perform premixing. That is, premixing may be performed by adding a pigment to an aqueous medium in which at least a pigment dispersion resin and water are mixed. Such a premixing operation is preferable because it improves wettability of the pigment surface and promotes adsorption of the dispersant to the pigment surface.

  The disperser used in the above-described pigment dispersion treatment may be any disperser that is generally used, and examples thereof include a ball mill, a roll mill, a sand mill, a bead mill, and a nanomizer. Among these, a bead mill is preferably used. Examples of such include a super mill, a sand grinder, an agitator mill, a glen mill, a dyno mill, a pearl mill, and a cobol mill (all are trade names).

  Furthermore, in the pigment premixing and dispersion treatment described above, the pigment dispersion resin may be dissolved or dispersed only in water, or may be dissolved or dispersed in a mixed solvent of a water-soluble solvent and water.

  Since the ink of the present invention is for inkjet recording, it is preferable to use a pigment having an optimum particle size distribution. That is, in order to make it possible to suitably use an ink containing pigment particles in an ink jet recording method, it is preferable to use a pigment having an optimum particle size distribution in view of demands such as nozzle clogging resistance. Examples of a method for obtaining a pigment having a desired particle size distribution include the following methods. Reduce the size of the grinding media of the disperser as mentioned above, increase the filling rate of the grinding media, increase the processing time, classify with a filter or centrifuge after grinding, etc. There are methods such as a combination of these methods.

As the printing paper for printing the aqueous pigment ink of the present invention described above, known ones can be used. For example, high-quality paper, coated paper, art paper, cast paper, or synthetic paper can be used. The surface of the substrate may be a smooth surface, an uneven surface, or transparent, translucent, or opaque.
Further, two or more of these substrates may be bonded to each other. Furthermore, a peeling adhesive layer or the like may be provided on the opposite side of the printing surface, or an adhesive layer or the like may be provided on the printing surface after printing.

  Furthermore, a printing paper in which an ink receiving layer made of a water-soluble resin having a carboxyl group and / or a sulfonic acid group or a water-dispersible resin is coated on the printing paper can be used. As a result, it is possible to obtain a higher quality image without white streaks, color unevenness, and intercolor bleeding, as compared with the case of printing directly on the printing paper. This is because the carboxyl group and / or sulfonic acid group of the ink receiving layer works preferentially on the wettability of the ink due to the interaction with the poorly water-soluble glycol ether and amino alcohol contained in the aqueous pigment ink of the present invention, and widens the ink dots. At the same time, it is considered that ink penetration can be promoted.

The ink receiving layer can be applied by a known method, for example, roll coater method, blade coater method, air knife coater method, gate roll coater method, bar coater method, size press method, spray coating method, or gravure coater method. And curtain coater method. The ink receiving layer may be provided on only one side of the paper or may be provided on both sides.
Further, the ink receiving layer forming coating agent can be filled in an ink cartridge of an ink jet printer, and printing can be performed by the ink jet method at the same time as or before the other color ink.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, “part” represents “part by weight”, and “%” represents “% by weight”. Furthermore, Table 1 shows the structures of the fluorosurfactants represented by the general formula (I) in the examples.

(Production example of pigment dispersion resin)
A reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer was charged with 93.4 parts of triethylene glycol monomethyl ether and replaced with nitrogen gas. The inside of the reaction vessel was heated to 110 ° C., and a mixture of 35.0 parts of lauryl methacrylate, 35.0 parts of styrene, 30.0 parts of acrylic acid, and 6.0 parts of V-601 (manufactured by Wako Pure Chemical Industries) was added for 2 hours. Over the course of the polymerization reaction. After completion of the dropwise addition, the mixture was further reacted at 110 ° C. for 3 hours, and then 0.6 part of V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the reaction was further continued at 110 ° C. for 1 hour to prepare a pigment dispersion resin 1 solution. Obtained. The weight average molecular weight of the pigment dispersion resin 1 was about 16000.
Further, after cooling to room temperature, 37.1 parts of dimethylaminoethanol was added for neutralization. This is the amount that neutralizes 100% of acrylic acid. Further, 200 parts of water was added to make it aqueous. 1 g of this was sampled, heated and dried at 180 ° C. for 20 minutes to measure the non-volatile content, and water was added so that the non-volatile content of the previously aqueous resin solution was 20%. As a result, an aqueous solution having a non-volatile content of 20% of the pigment dispersion resin 1 was obtained.

(Production example of water-dispersible resin fine particles)
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser was charged with 40 parts of ion exchange water and 0.2 part of Aqualon KH-10 (Daiichi Kogyo Seiyaku Co., Ltd.) as a surfactant. , 40 parts of 2-ethylhexyl acrylate, 50 parts of methyl methacrylate, 7 parts of styrene, 2 parts of dimethylacrylamide, 1 part of methacrylic acid, 53 parts of ion-exchanged water, and Aqualon KH-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) An additional 1% of the pre-emulsion with 1.8 parts premixed was added. After raising the internal temperature to 60 ° C. and sufficiently purging with nitrogen, 10 parts of a 5% aqueous solution of potassium persulfate and 20 parts of a 1% aqueous solution of anhydrous sodium bisulfite were added to initiate polymerization. After maintaining the reaction system at 60 ° C. for 5 minutes, the remaining pre-emulsion, 5% aqueous solution of potassium persulfate, and 1% aqueous solution of anhydrous sodium bisulfite were maintained for 1.5 hours while maintaining the internal temperature at 60 ° C. The mixture was added dropwise and stirring was continued for 2 hours. After confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30 ° C. Diethylaminoethanol was added to adjust the pH to 8.5, and the solid content was adjusted to 40% with ion exchange water to obtain an aqueous dispersion of water-dispersible resin fine particles 1. In addition, solid content was calculated | required by 150 degreeC 20 minute baking residue.

(Production example of pigment dispersion)
20 parts of Pigment Yellow 74, 42.9 parts of water-dispersed pigment dispersion resin 1 and 37.1 parts of water were charged into a mayonnaise bottle as a pigment, predispersed with a disper, and then 250 parts of 0.8 mm diameter zirconia beads. Was dispersed as a dispersion medium, and this dispersion was performed with a paint shaker to obtain a pigment dispersion. At this time, the ratio of the non-volatile content between the pigment and the pigment-dispersed resin 1 is pigment / dispersed resin (non-volatile) = 7/3.

(Ink production example)
20 parts of the obtained pigment dispersion, 30 parts of propylene glycol, 27.5 parts of water,
General formula (I) _C 6 as a fluorine-based surfactant represented by _{F 13 -CH 2 CH (OH)} CH 2 S (CH 2) 2 COONH 4 0.5 parts of
1 part of Surfynol 465 (Air Products and Chemicals Inc.) as a nonionic surfactant represented by the general formula (II), 0.5 part of dimethylethanolamine as an amino alcohol, and an aqueous dispersion of water-dispersible resin fine particles 1 Was prepared by mixing 3.3 parts of a 30% aqueous dispersion of AF-41 (manufactured by Gifu Serask Manufacturing Co., Ltd.) as a water-dispersible wax and filtering with a 10 μm membrane filter. did. At this time, 4 parts of pigment, 1.7 parts of pigment-dispersed resin, 5 parts of water-dispersible resin fine particles, and 1 part of water-dispersible wax are contained in 100 parts of ink.

(Production example of coating agent for forming ink receiving layer)
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, 136.2 parts of ion exchange water, 1.6 parts of a 24% aqueous solution of RA-9607 (manufactured by Nippon Emulsifier Co., Ltd.) as a surfactant, and 0.13 parts of sodium bicarbonate was added as a buffering agent. Separately, 0.5 part of diallyl phthalate, 40 parts of methacrylic acid, 30 parts of ethyl acrylate, 29.5 parts of butyl acrylate, 80 parts of ion-exchanged water, and the above-mentioned surfactant An additional 5% of the pre-emulsion pre-mixed with 6.4 parts of a 24% aqueous solution of RA-9607 was added. After raising the internal temperature to 75 ° C. and sufficiently purging with nitrogen, 10% of 6 parts of a 5% aqueous solution of potassium persulfate was added to initiate polymerization. After maintaining the reaction system at 75 ° C. for 5 minutes, the remaining pre-emulsion and the remaining 5% aqueous solution of potassium persulfate are added dropwise over 2 hours while maintaining the internal temperature at 75 to 80 ° C., and stirring is further performed for 2 hours. Continued. After confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30 ° C. A vinyl emulsion was obtained by adjusting the solid content to 30% with ion-exchanged water. In addition, solid content was calculated | required by 150 degreeC 20 minute baking residue.
To 100 parts of the obtained vinyl emulsion, 200 parts of purified water was blended to prepare a coating agent 1 for forming an inkjet ink receiving layer having a solid content of 10%.

(Example of printing paper production)
The coating agent 1 for forming the ink-jet ink receiving layer is coated on a coated paper [Oji Paper Co., Ltd., OK Top Coat Plus] with a wire bar No. 2 and dried in a hot air oven at 60 ° C. for 2 minutes to prepare a printing paper 1 having an inkjet ink receiving layer laminated thereon.

(Production example of printed matter)
Ink was filled in a cartridge of an inkjet printer (Epson "PM-750C"), and coated paper (+ Oji Paper Co., Ltd. OK top coat, basis weight 104.7g / ^{m 2)} and a pattern is printed on the printing paper 1 A printed matter for evaluation was produced.

(Examples 1-6)
According to the composition described in Table 2, a dispersion, an ink, and a printed matter for evaluation were prepared in the same manner as in the above production example.
(Comparative Examples 1-5)
According to the composition described in Table 3, a dispersion, an ink, and a printed matter for evaluation were prepared in the same manner as in the above production example.

  Table 4 shows the evaluation results of the storage stability of the ink over time, white streaks / color unevenness of the printed matter, and bleeding. A specific evaluation method will be described below.

(Ink storage stability over time)
After the ink was stored in a thermostat at 70 ° C. for 2 weeks and accelerated over time, changes in the viscosity, dispersed particle size, and filterability of the ink before and after aging were evaluated. When the change rate of viscosity and dispersed particle size before and after storage at 70 ° C. for 2 weeks is within ± 5%, ○ if it is ± 5% or more and ± 10% or less, ○ if it is ± 10% or more and ± 20% or less X is 20% or more.

(White streaks / color unevenness of printed matter)
In a solid printing section with a printing rate of 100%, visually, white spots or white streaks appear to be x, white spots or white streaks appear to be Δ, white spots or white lines are Nothing was marked as ○. In particular, “A” indicates that there is no white spot or white streak and there is no density unevenness and a uniform solid print portion is obtained.

(Bleed of printed matter)
At the boundary where the single-color solid printing part with a printing rate of 100% is multiplied by different colors, visually, x is clearly blurred, Δ is slightly blurred, and there is no bleeding Was marked as ○. In particular, the case where a printed part having no blur was obtained even when three colors were overlaid was marked with ◎.

Claims (8)

In an inkjet pigment ink containing a pigment, a pigment dispersion resin, water, a water-soluble solvent, and a fluorine-based surfactant, the fluorine-based surfactant is a compound represented by the following general formula (I) Ink-jet pigment ink characterized by the above.

(Wherein Rf is a C 1-6 perfluoroalkyl group, X is COO, SO ₃ , SO ₄ , PO ₄ , Y is NH ₄ , N (C ₂ H ₅ ) ₃ , N (C ₂ H ₅ OH) ₃ , Li, Na, K are represented, and m and n represent an integer of 1-6.)   2. The inkjet pigment ink according to claim 1, wherein the fluorine-based surfactant is contained in an amount of 0.05 to 1% by weight based on the ink composition. The inkjet pigment ink according to claim 1 or 2, further comprising a nonionic surfactant represented by the following general formula (II).

(In formula, p and q represent the integer of 0-40.)   Furthermore, amino alcohol is contained, The pigment ink for inkjets of any one of Claims 1-3 characterized by the above-mentioned.   The ink-jet pigment ink according to claim 1, further comprising water-dispersible resin fine particles.   Furthermore, water-dispersible wax is contained, The pigment ink for inkjets of any one of Claims 1-5 characterized by the above-mentioned.   A printed matter obtained by printing the ink-jet pigment ink according to any one of claims 1 to 6 on a printing paper. The ink-jet pigment ink according to any one of claims 1 to 6, wherein the water-soluble resin having a carboxyl group and / or a sulfonic acid group and / or a water dispersibility having a carboxyl group and / or a sulfonic acid group are formed on the printing paper. Printed matter printed on printing paper coated with resin ink-receiving layer.