JP2008126643A - Recording method and printed matter - Google Patents

Abstract

An ink repellent film formed on a substrate surface of an ink jet head has a shape in which the portion near the opening from the edge of the opening is less likely to be peeled by wiping and has excellent ejection stability. An inkjet head is used so that the recording performance can be maximized.
As a recording medium (such as inkjet paper), the amount of ink transferred to the recording medium at a contact time of 100 ms under conditions of an air temperature of 23 ° C. and a relative humidity of 50% RH is 4 to 15 ml / m ² . And a transfer amount of ink to a recording medium at a contact time of 400 ms is 7 to 20 ml / m ² .
[Selection] Figure 2

Description

  The present invention relates to a recording method for recording image information on a recording medium using an inkjet recording method, and a printed matter.

  2. Description of the Related Art Conventionally, there are inkjet recording apparatuses that perform image formation with ink, such as a printer, a facsimile machine, a copying machine, and a plotter. In such an ink jet recording apparatus, since an image is formed by ejecting ink from a nozzle member, there is one in which an ink repellent film is formed on the surface on the ink ejection surface side.

  With regard to such an ink jet head, Patent Document 1 discloses a treatment method for forming an ink repellent thin film by plasma polymerization of silicone oil, and a nozzle plate of an ink jet head having an ink repellent thin film by this method.

Further, in Patent Document 2, after forming an ink repellent film of a fluororesin polymer film or a silicone resin polymer film, it is heat-treated in an inert atmosphere excluding oxygen and moisture, and is contained in the ink repellent film. The liquid material to be evaporated is evaporated to cure the ink repellent film.
JP 2003-72085 A JP 2003-72086 A

However, the above-mentioned Patent Documents 1 and 2 do not consider the optimization of the shape of the edge portion (near the edge of the opening portion) around the nozzle hole in the ink repellent film.
That is, generally, the water repellent layer is formed by masking the nozzle hole portion, or the water repellent layer in the nozzle hole portion is removed after the water repellent layer is formed on the surface of the nozzle plate. In these cases, as shown in FIG. 8A, the ink repellent film at the edge portion around the nozzle hole becomes smaller as the cross-sectional area in the plane perpendicular to the center line of the opening becomes farther from the nozzle plate, and the sharp end ( A shape having a pointed portion).

When the nozzle surface having such a shape as shown in FIG. 8A is wiped with a wiper 7 formed of a material such as rubber, the wiper also hits the edge portion as shown in FIG. There is a possibility that the ink repellent film may be easily peeled off.
Further, as shown in FIG. 8C, when ink is filled, a meniscus P is formed at the boundary between the ink repellent film 1 ′ and the nozzle plate 2, and a meniscus Q is formed at the tip of the ink repellent film 1 ′. May be formed. For this reason, there is a possibility that variations in ink ejection stability may occur.

  In addition, there has been no provision of a recording method that maximizes the recording performance of such an ink jet head in consideration of the relationship with the ink and recording medium used for recording.

  The present invention has been made in view of such a situation, and a portion in the vicinity of the opening from the edge of the opening of the ink repellent film formed on the substrate surface of the ink jet head has a shape that does not easily peel off even by wiping. Another object of the present invention is to provide a recording method and a printed matter that can make the best use of the recording performance by using an inkjet head formed in a shape excellent in jetting stability.

In order to achieve such an object, the recording method according to the present invention includes an ink repellent film formed on the surface of a substrate of an ink jet head in which an opening for liquid ejection is opened, and the ink repellent film is formed in the vicinity of the opening. A recording method using ink ejected from an inkjet head formed so that a cross-sectional area in a plane perpendicular to the center line of the opening gradually increases as the distance from the substrate surface increases. The amount of transfer of the ink to the recording medium at a contact time of 100 ms under a relative humidity of 50% RH is 4 to 15 ml / m ² , and the amount of transfer of the ink to the recording medium at a contact time of 400 ms is 7 It records on the recording medium which is -20ml / m < ² >.

The recording medium has a transfer amount of pure water to a recording medium of 4 to 26 ml / m ² at a contact time of 100 ms under conditions of an air temperature of 23 ° C. and a relative humidity of 50% RH, and pure water at a contact time of 400 ms. The amount of transfer to the recording medium is preferably 5 to 29 ml / m ² .

  The recording medium is preferably a recording medium having a support and a coating layer provided on at least one surface of the support.

The recording medium is composed of at least a substrate and a coating layer, and the solid content adhesion amount of the coating layer is preferably 0.5 to 20.0 g / m ² .

The recording medium preferably has a basis weight of 50 to 250 g / m ² .

  The recording medium is preferably subjected to a super calendar process.

The recording medium contains a pigment, and the pigment is preferably kaolin.
The recording medium may contain a pigment, and the pigment may be heavy calcium carbonate.

The recording medium preferably contains an aqueous resin.
The aqueous resin is preferably a water-soluble resin or a water-dispersible resin.

  The ink preferably contains at least water, a colorant, and a wetting agent.

  The surface tension of the ink at 25 ° C. is preferably 15 to 40 mN / m.

  The ink contains a dispersible colorant as a colorant, and the dispersible colorant preferably has an average particle size of 0.01 to 0.16 μm.

  The viscosity of the ink at 25 ° C. is preferably 1 to 30 cps.

  The ink preferably contains a surfactant, and the surfactant is preferably a fluorosurfactant.

In the printed material according to the present invention, an ink repellent film is formed on the surface of an ink jet head substrate having an opening for discharging liquid, and the center of the opening in the vicinity of the opening of the ink repellent film is formed. Contact under conditions of an air temperature of 23 ° C. and a relative humidity of 50% RH by ink ejected from an ink jet head formed so that a cross-sectional area in a vertical plane gradually increases as the distance from the substrate surface increases. The amount of transfer of the ink to the recording medium at a time of 100 ms is 4 to 15 ml / m ² , and the amount of transfer of the ink to the recording medium at a contact time of 400 ms is 7 to 20 ml / m ^2. It is characterized by that.

  As described above, according to the present invention, the portion near the opening from the edge of the opening of the ink repellent film formed on the substrate surface of the inkjet head has a shape that does not easily peel off even by wiping, and the jetting stability In addition, it is possible to provide a recording method and a printed matter that can make the most of the recording performance using an inkjet head formed in an excellent shape.

<Inkjet head, cartridge equipped with the head, and inkjet recording apparatus>
1 and 2 are sectional views of an ink jet head nozzle plate prepared according to this embodiment. In the present embodiment, a nozzle plate 2 that is a base material of an ink jet head is manufactured by Ni electroforming, and an ink repellent film 1 that is a silicone resin film having a thickness of 0.1 μm or more is formed on the surface thereof. The surface roughness is preferably Ra = 0.2 or less. The film thickness of the ink repellent film 1 is more preferably 0.5 μm or more.
When the ink 3 is filled, a meniscus (liquid level) P is formed at the boundary between the ink repellent film 1 and the nozzle plate 2 made of a silicone resin film, as shown in FIG.

  The opening of the nozzle plate 2 is opened so that a cross section by a plane perpendicular to the center line indicated by the alternate long and short dash line in FIG. 2 is substantially circular with the center line as the center. Further, the ink repellent film 1 formed on the ink ejection surface of the nozzle plate 2 is formed so that the cross-sectional area of the opening portion by a plane perpendicular to the center line gradually increases as the distance from the nozzle plate 2 increases.

More specifically, the opening portion of the ink repellent film 1 has a round shape in which the curve from the edge of the opening portion of the nozzle plate 2 to the vicinity of the opening portion has a radius of curvature r, as shown in FIG. The radius of curvature r is preferably equal to or greater than the thickness d other than the vicinity of the opening of the ink repellent film 1.
The thickness d is a thickness in a portion other than the round portion that is an opening portion of the ink repellent film 1, and may preferably be the maximum thickness of the ink repellent film.

  As described above, the opening portion of the ink repellent film 1 connected to the opening portion of the nozzle plate 2 has a shape without a sharp point (smooth curve without a pointed portion) and a curve without a catching portion. As a result, even when wiping is performed with a wiper formed of a material such as rubber, it is possible to prevent the ink-repellent film 1 from being separated from the nozzle plate 2 due to the pointed portion being caught by the wiper.

  Further, as shown in FIG. 2B, a tangent line passing through the opening portion edge of the ink repellent film 1 in a cross section in a plane including the center line of the opening of the nozzle plate 2 is connected to the opening portion edge. The angle θ from the surface of the nozzle plate 2 including the edge of the opening of the nozzle plate 2 is preferably less than 90 degrees.

As described above, since the angle θ between the tangent at the edge of the opening of the ink repellent film 1 and the nozzle plate surface 2 is less than 90 degrees, as shown in FIG. 2C, the ink repellent film 1 and the nozzle The possibility that the meniscus (liquid level) P is stably formed in the boundary portion with the plate 2 and the meniscus P is formed in other portions can be greatly reduced.
As a result, the meniscus formation surface can be stabilized, so that the ink ejection stability when forming an image in an image forming apparatus using an ink jet head including the nozzle plate 2 is improved. it can.

As the silicone resin used in the present embodiment, a room temperature curable liquid silicone resin is desirable, and a silicone resin with a hydrolysis reaction is particularly preferable. In the following examples, SR2411 manufactured by Toray Dow Corning Co., Ltd. was used.
Table 1 below shows the shape of the ink repellent film 1 in the inkjet head according to the present embodiment from the edge of the nozzle plate 2 to the vicinity of the edge of the nozzle, the ink pool around the nozzle, the edge peeling, and the ejection stability. It is the result evaluated about sex.

In the case where the edge portion of the ink repellent film 1 (in the vicinity of the edge of the opening portion) includes a substantially sharp end, an ink pool is seen around the nozzle, and the edge is peeled off by wiping.
In the round shape, no ink accumulation occurred, but as a comparative example, r <d as illustrated in FIG. 3A, part of the edge was peeled off, and FIG. In the case of θ> 90 degrees as exemplified in FIG. 5, the ejection of droplets was unstable.

  That is, as shown in FIG. 3C, when r <d or θ> 90 degrees, a meniscus (liquid level) is formed at the boundary between the ink repellent film 1 and the nozzle plate 2 when the ink 3 is filled. There is a case where P is formed and a case where the meniscus Q is formed at a convex portion (a portion where the cross-sectional area perpendicular to the center line in the opening portion is the smallest) in the ink repellent film 1 ′. It is possible. For this reason, variation occurs in the ejection stability of the ink when the image is formed by the image forming apparatus using the ink jet head including the nozzle plate 2.

  Next, the manufacturing method of the nozzle member of the inkjet head according to the above-described embodiment will be described.

FIG. 4 is a diagram illustrating a configuration in which the ink-repellent film 1 is formed by applying a silicone resin by application using the dispenser 4 according to the present embodiment.
A dispenser 4 for applying a silicone solution is disposed on the ink discharge surface side of the nozzle 2 by Ni electroforming so that the nozzle plate 2 and the tip of the needle 5 remain at a predetermined distance. By scanning the dispenser 4 while discharging silicone from the tip of the needle 5, it is possible to selectively form a silicone resin film on the ink discharge surface of the nozzle plate 2 as shown in FIGS. It was.

  The silicone resin used in the present embodiment was a room temperature curing type silicone resin SR2411 (manufactured by Toray Dow Corning Co., Ltd.) viscosity: 10 mPa · s. However, a slight amount of silicone was found around the nozzle holes and the back of the nozzle plate. The silicone resin film thus selectively formed had a thickness of 1.2 μm and a surface roughness (Ra) of 0.18 μm.

As shown in FIG. 5A, the application port at the tip of the needle 5 according to the present embodiment has a width that is equal to the application width to the nozzle plate 2 that is the application target. Thereby, the application | coating to the whole coating object can be completed only by scanning the dispenser 4 once in the application direction.
That is, the scanning direction for the coating operation can be set to only one direction, and the necessity of changing the direction as shown in FIG. 5B or scanning in the opposite direction can be eliminated.

  Here, as shown in FIG. 5 (b), the tip of the general needle 5 is much narrower than the application width to the nozzle plate 2 that is the application target, so in order to complete the application to the entire application target, It is necessary to scan in a plurality of directions by changing the scanning direction for the coating operation by 90 degrees, or scanning in the opposite direction, and it is difficult to apply the coating to the entire coating target with a uniform thickness.

  According to the present embodiment, the width of the application port at the tip of the needle 5 is ensured by the width of application to the nozzle plate 2 that is the application target, so that the thickness applied over the entire application target can be made uniform. The surface finish can be made with high accuracy.

FIG. 6 is a diagram illustrating a coating operation using the dispenser 4 according to the present embodiment. Although the basic configuration is the same as that of FIG. 4 described above, silicone is applied while jetting the gas 6 from the nozzle holes (openings) of the nozzle plate 2. As the gas 6, various gases may be used as long as they do not easily cause a chemical reaction with the silicone to be applied. For example, air may be used.
Thus, a silicone resin film can be formed only on the nozzle surface excluding the nozzle holes of the nozzle plate 2 by performing the coating while jetting the gas 6 from the nozzle holes.

Further, as described above, when the gas 6 is applied without using the same silicone resin, and the silicone resin enters to a predetermined depth and then the gas 6 is injected from the nozzle 2, as shown in FIG. In addition, an ink repellent layer of silicone resin can be formed to a desired depth (for example, about several μm) on the inner wall of the nozzle.
That is, in addition to the ink repellent film 1 on the ink ejection surface described above, a very thin ink repellent film 1a (ink repellent film on the inner wall of the opening) is formed from the edge of the opening of the nozzle plate 2 to a predetermined depth. Can do.

  Wiping was performed on the ink-repellent film 1 of the nozzle plate thus produced using EPDM rubber (rubber hardness 50 degrees). As a result, the ink repellent film 1 of the nozzle plate was able to maintain good ink repellency even after 1000 times of wiping. Further, the nozzle member on which the ink repellent film was formed was immersed in ink at 70 ° C. for 14 days. As a result, it was possible to maintain the ink repellency unchanged from the initial stage.

  The nozzle plate (S1) on which the ink-repellent film 1 of the silicone resin is formed according to this embodiment and the nozzle plate (C1) that has been subjected to eutectoid plating of Ni / PTFE and heat-treated at 350 ° C. for 60 minutes are used. Table 2 shows a comparison with the ink repellency for each ink. The ink conditions for investigating the ink repellency were surface tension: 20 mN / m and 35 mN / m, and those containing and not containing a fluorosurfactant. The fluorosurfactant used was trade name: FS-300 (manufactured by DuPont). In the present embodiment, it is preferable that the surface tension of the fluorosurfactant to be used is low. For example, it is preferably 70 mN / m, more preferably 50 mN / m, and further preferably 15 to 50 mN / m. m, particularly preferably 15 to 40 mN / m. In this way, the wettability of the ink is improved with respect to a recording medium such as paper, and a high-quality printed matter can be obtained.

  As shown in Table 2, with the conventional nozzle C1, ink repellency was not obtained with respect to ink having a surface tension of 20 mN / m and containing a fluorosurfactant. On the other hand, when the nozzle plate S1 produced according to this embodiment was tested using all the inks described above, good ink repellency could be obtained for all of these inks.

As the water repellent material constituting the ink repellent film 1 according to the present embodiment, an organic compound having a fluorine atom, particularly an organic substance having a fluoroalkyl group, an organic silicon compound having a dimethylsiloxane skeleton, and the like can be used.
As the organic compound having a fluorine atom, fluoroalkylsilane, alkane having a fluoroalkyl group, cambonic acid, alcohol, amine and the like are desirable. Specifically, the fluoroalkylsilane includes heptadecafluoro-1,1,2,2-tetrahydrodecyltrimethoxysilane, heptadecafluoro-1,1,2,2-tetrahydrotrichlorosilane; fluoroalkyl As the alkane having a group, octafluorocyclobutane, perfluoromethylcyclohexane, perfluoro-n-hexane, perfluoro-n-heptane, tetradecafluoro-2-methylpentane, perfluorododecane, perfluoroeucosane; and carboxylic acid having a fluoroalkyl group Perfluorodecanoic acid, perfluorooctanoic acid; alcohols having a fluoroalkyl group include 3, 3, 4, 4, 5, 5, 5-heptafluoro-2-pentanol; The emissions, heptadecafluoro over 1,1,2,2-tetrahydro-decyl amine. Examples of organosilicon compounds having a dimethylsiloxane skeleton include α, w-bis (3-aminopropyl) polydimethylsiloxane, α, w-bis (3-glycidoxypropyl) polydimethylsiloxane, and α, w-bis (vinyl) poly. Examples thereof include dimethylsiloxane.

As another water-repellent material, an organic compound having a silicon atom, particularly an organic compound having an alkylsiloxane group can be used.
Examples of the organic compound having an alkylsiloxane group include an alkylsiloxane group having two or more alkylsiloxane groups and cycloaliphatic epoxy groups in the molecule constituting the alkylsiloxane epoxy resin composition. The polymer compound (A) containing the structural unit represented by (a) and (b) is mentioned.

  The polymer compound (A) having a structure such as the above general formulas (a) and (b) also functions as a binder when used in combination with other water-repellent compounds. That is, it is possible to provide a function of improving workability as a dry coating film that improves the applicability of the ink-repellent composition and increases the drying property after evaporation of the solvent.

Thus, in this embodiment, since the ink repellent film 1 is formed by application using the dispenser 4, the material of the ink repellent film 1 is hardened at room temperature in the air, that is, long in the air at room temperature. Even materials that cannot be left for a long time can be used.
Further, as described above, the material of the ink repellent film 1 may be a fluororesin or a silicone resin.

As described above, in the ink jet head of this embodiment, the ink repellent film 1 is formed on the ink ejection surface side of the nozzle plate 2, and the opening portion of the ink repellent film 1, that is, the opening from the edge of the opening of the nozzle plate 2 is opened. The vicinity of the edge is formed to have a round shape.
For this reason, the nozzle edge portion (opening portion of the ink repellent film 1) is protected against an external force such as wiping, and a highly durable inkjet head can be obtained.

  Further, in the inkjet head according to the present embodiment, the radius of curvature r of the round portion of the ink repellent film 1 formed on the surface of the nozzle plate 2 is equal to or less than the thickness d other than the opening portion of the ink repellent film 1. Peeling in the vicinity of the edge of the opening portion of the ink film 1 hardly occurs, and an ink jet head with good ejection stability can be obtained.

  In addition, since the inkjet head according to the present embodiment has an inclination θ of a tangent line of the round portion passing through the nozzle edge portion of 90 degrees or less, the ejected ink droplet does not touch the ink repellent film 1 and has good ejection stability. It can be.

  In addition, since the thickness d of the ink repellent film 1 formed on the surface of the ink jet head according to the present embodiment is 10 μm or less, it is possible to provide a highly durable and durable nozzle.

Further, since the ink repellent film 1 formed on the nozzle plate of the ink jet head according to the present embodiment may be made of a fluororesin, it is difficult for ink to remain when wiping and stable ejection characteristics can be obtained.
Further, since the ink repellent film 1 formed on the nozzle plate of the ink jet head according to the present embodiment may be a silicone resin, the ink mobility is good, and the ink adhering to the periphery of the nozzle is easily attracted to the nozzle hole. Therefore, the periphery of the nozzle hole can always be kept clean and stable jetting characteristics can be obtained.

In addition, since the nozzle plate base material of the ink jet head according to the present embodiment may be a metal, a stable ink jet head having very high rigidity can be obtained.
In addition, since the nozzle plate substrate of the ink jet head according to the present embodiment may be a resin, the surface of the ink repellent film 1 has very good adhesion, and the ink jet head can have excellent durability. .

  In addition, since the ink repellent film 1 can be formed in the atmosphere in the method for manufacturing an ink jet head according to this embodiment, the ink repellent film 1 can be easily formed with inexpensive equipment.

  Further, in the ink jet head manufacturing method according to the present embodiment, since the material of the ink repellent film is applied by the dispenser, a necessary amount of resin can be applied to a required place, and the film thickness of the ink repellent film to be formed d can be adjusted freely and precisely, and the ink repellent film 1 can be formed at a very low cost.

  Further, in the method of manufacturing an ink jet head according to the present embodiment, the resin is applied to the surface with a dispenser while jetting gas from the back surface side to the front surface side of the nozzle substrate through the nozzle holes of the nozzle substrate. The nozzle hole can be prevented from being filled with the ink film 1, and the ink repellent film 1 can be formed at a very low cost and with a high yield.

  In addition, in the method of manufacturing an ink jet head according to the present embodiment, gas is ejected from the back surface side of the nozzle substrate to the surface side through the nozzle holes after the resin is applied to the nozzle substrate surface with a dispenser. The resin film can be applied to the inner wall of the nozzle hole up to the depth, and the ink repellent film 1 can be formed at a very low cost and with a high yield.

  In addition, according to the ink jet head including the nozzle member of the ink jet head according to the present embodiment, the ink-repellent film is not easily peeled off even by wiping during head cleaning or the like, and the jetting stability is excellent. In addition, a highly durable ink jet head can be provided.

In addition, according to the cartridge including the inkjet head according to the present embodiment, the ink-repellent film on the head portion is hardly peeled off even by wiping during head cleaning and the like, and the ejection stability is excellent, so that the image quality is high. A highly durable inkjet head can be provided.
The cartridge may be used for replacement by providing an ink supply means for the ink jet head and a means for attaching to the ink jet recording apparatus main body.

  Moreover, since the inkjet recording apparatus provided with the inkjet head according to the present embodiment is equipped with the inkjet head as the above-described embodiment, the inkjet recording apparatus is inexpensive, excellent in durability, and has stable ejection performance. It can be.

  In addition, since the ink jet recording apparatus according to the present embodiment can use ink having a low surface tension, the fixability of the ink to the adherend (for example, paper) can be improved.

  In addition, the ink jet recording apparatus according to the present embodiment can use an ink containing a fluorosurfactant as the ink to be used, so that it is possible to form an image with good color developability.

  In addition, since the ink jet recording apparatus according to the present embodiment may be a pigment ink, it is possible to form a high quality image with excellent weather resistance and water resistance even with plain paper.

  Here, conventionally, a method using a fluororesin has been known as an ink repellent layer for a nozzle plate of an inkjet head. For example, Ni / PTFE eutectoid plating on the metal nozzle plate surface and heat treatment to form a PTFE thin film on the nozzle plate surface, or a fluorine-based water repellent on the metal or resin nozzle plate surface That is the method of coating. In the case of a nozzle plate using such a fluororesin as an ink repellent layer, a conventionally known dye ink or pigment ink having a surface tension of about 30 mN / m or more can have good ink repellency. However, it has been difficult to provide sufficient ink repellency with an ink having a low surface tension of 15 to 30 mN / m or an ink to which a fluorosurfactant is added.

  Conventionally, there has been shown a method of forming an ink repellent layer with good ink mobility by forming a silicone resin film on the nozzle plate surface of an inkjet head. As the method, there are a method in which a liquid silicone resin material is vacuum-deposited, and a method in which a silicone oil is formed by plasma polymerization. In these methods, it is necessary to perform a vacuum treatment during film formation, which requires large equipment and high costs. Further, when a silicone resin film is formed by a method such as vacuum deposition or plasma polymerization, there is a problem that defects such as pinholes are likely to occur because the film formed for a long time is very thin. In addition, it is difficult to increase the thickness of the film by a method such as vacuum deposition or plasma polymerization, and it is difficult to ensure sufficient durability against the light pink or ink.

  Conventionally, a method of forming an ink repellent layer on the surface of a nozzle plate by immersing the nozzle plate in a solution in which an ink repellent agent is dissolved in a state where gas is injected from a nozzle hole has been shown. Since it is immersed in the solution as it is, bubbles are generated in the solution. If the solution is of a type that cures at room temperature, the solution must be left in the atmosphere, making it difficult to maintain the liquid state, and the ink repellent layer thickness control becomes impossible due to changes in the viscosity of the solution. End up.

  In contrast to such conventional techniques, the nozzle plate ink repellent layer of the ink jet head of this embodiment forms a uniform and smooth silicone resin film having a low surface tension with efficient ink repellency on the nozzle plate surface. Even inks with low surface tension of -30mN / m and inks with fluorinated surfactants can have sufficient ink repellency, and the film maintains ink repellency with excellent durability and durability. Therefore, it is possible to provide an inkjet head with good print quality over a long period of time.

In addition, in the inkjet head nozzle plate ink repellent treatment method according to the present embodiment, a uniform and smooth silicone resin is applied to the surface of the nozzle plate by applying a liquid silicone to a required location of the nozzle plate in which the nozzle holes are previously formed with a dispenser. A film is formed. By setting the thickness of the silicone resin film to 0.1 μm or more, more preferably 0.5 μm or more, durability against wiping and ink resistance can be improved.
In addition, by setting the surface roughness of the silicone resin to Ra = 0.2 μm or less, it is possible to reduce ink remaining after wiping. In order to form a smooth surface, the viscosity of the liquid silicone used as a material is desirably 1000 cp or less.

  Moreover, in the nozzle plate ink repellent treatment method of the ink jet head according to the present embodiment, the silicone plate is coated (applied) with a dispenser as described above while gas is ejected from the nozzle holes, and the silicone resin is cured to thereby form the nozzle plate. An ink repellent layer of silicone resin can be formed only on the surface. The ink-repellent layer can be formed to a desired depth of the inner wall of the nozzle hole by coating a silicone resin on the surface of the nozzle plate and then jetting gas from the nozzle hole.

  Further, the silicone resin that is a material used for the ink repellent treatment of the nozzle plate of the ink jet head according to the present embodiment is a room temperature curable liquid silicone resin or elastomer. Thereby, a durable silicone resin film can be formed by simply leaving it in the air at room temperature for several minutes to an hour after coating.

  Further, the silicone resin that is a material used for the ink repellent treatment of the nozzle plate of the ink jet head according to the present embodiment is a heat-curable liquid silicone resin or elastomer. Thereby, a durable silicone resin film can be formed by performing heat treatment at several tens of degrees Celsius to several hundreds of degrees Celsius for several minutes to several tens of degrees after coating.

In addition, the silicone resin that is a material used for the ink repellent treatment of the nozzle plate of the ink jet head according to the present embodiment is an ultraviolet curable liquid silicone resin or elastomer. Thereby, a durable silicone resin film can be formed by irradiating an ultraviolet ray of 500 to 1000 mJ / cm ² after coating.

As described above, the nozzle member of the ink jet head according to the present embodiment is the same as the nozzle member of the ink jet head in which the ink repellent layer formed of silicone resin is formed on the ink ejection surface side. Is 0.1 μm or more, more preferably 0.5 μm or more.
Thus, since the layer of 0.1 μm or more is uniformly and smoothly formed on the ink ejection surface side using a silicone resin, an inkjet nozzle excellent in durability against wiping and ink repellency can be obtained. In particular, the ink resistance can be improved due to the chemical resistance of the silicone resin.

The ink-repellent layer has a surface roughness Ra of 0.2 μm or less.
Thus, since the surface roughness is Ra = 0.2 μm or less, the surface property is good, and there is little ink remaining due to wiping such as wiping.

The silicone resin may be applied using a dispenser on a nozzle plate surface in which nozzle holes are previously formed.
Thus, since the liquid silicone resin is applied to the surface of the nozzle plate in which the nozzle holes are previously formed by the dispenser, an ink-repellent film free from defects such as pinholes is selectively and efficiently formed on the surface of the nozzle plate. be able to.

In addition, the silicone resin has a viscosity of 1000 cp (centipoise) or less.
Thus, since the viscosity of liquid silicone is 1000 cp or less, an ink-repellent layer with good surface properties can be formed.

In the application using the dispenser, a silicone resin is coated while gas is ejected from a nozzle hole.
As described above, since the gas is jetted from the nozzle holes, it is possible to completely prevent the silicone from entering the inner wall of the nozzle and the surroundings to the back surface when coating the liquid silicone.

Further, in the application using the dispenser, a silicone resin is coated on the surface of the nozzle plate, and after the silicone penetrates to a desired depth of the nozzle hole, gas is injected from the nozzle hole.
As described above, since the gas is injected from the nozzle hole after the liquid silicone coating, the silicone resin can be coated to a desired depth of the inner wall of the nozzle.

The silicone resin is a room temperature curable liquid silicone resin or elastomer, which is coated on the surface of the nozzle plate and polymerized and cured by leaving it in the atmosphere at room temperature to form an ink-repellent film. And
As described above, since a room temperature curable type silicone resin or silicone elastomer is used as the silicone material, after coating on the nozzle surface, it is cured simply by leaving it in the air at room temperature, and has an ink repellency with excellent durability. A good film can be formed.

The silicone resin is a heat curable liquid silicone resin or elastomer, which is applied to the surface of the nozzle plate and cured by heat treatment to form an ink-repellent film.
In this way, since a heat-curable silicone resin or silicone elastomer is used as the silicone material, it is cured in a short time by performing a heat treatment after coating on the nozzle surface, resulting in a highly durable ink-repellent film. Can be formed.

The silicone resin is an ultraviolet curable liquid silicone resin or elastomer, which is applied to the surface of the nozzle plate and cured by irradiating with ultraviolet rays to form an ink-repellent film.
In this way, since an ultraviolet curable silicone resin or silicone elastomer is used as the silicone material, it is cured in a short time by irradiating ultraviolet rays after coating on the nozzle surface, resulting in a highly durable ink-repellent film. Can be formed.

In addition, the ink jet recording apparatus according to the present embodiment is characterized by using the nozzle member described above.
As described above, since the nozzle plate according to the present embodiment is used, the straightness of the ink droplets can be improved and the ejection bend can be reduced during ink ejection.

Further, in the ink jet recording apparatus according to the above-described embodiment, the ink used is a liquid having a surface tension of 70 mN / m or less.
In this way, since ink having a low surface tension can be used, the fixability of the ink to the adherend (for example, paper) can be improved.

The ink preferably contains a fluorine-based surfactant.
As described above, since the ink to be used contains the fluorosurfactant, it is possible to form an image with good color developability.

Moreover, it is preferable that said ink contains a pigment.
As described above, since the pigment ink is used, it is possible to form a high-quality image having excellent weather resistance and water resistance even with plain paper.

<Relationship between nozzle plate, ink and media (recording medium)>
As described above, the nozzle plate of the present embodiment is excellent in water repellency and ink repellency. Therefore, even when ink having a low surface tension is used, ink droplets can be formed (particulate). This is because the nozzle plate is not too wet and the ink meniscus is normally formed. When the meniscus is formed normally, the ink is not pulled in one direction when the ink is ejected. As a result, an ink ejection curve is small and an image with high dot position accuracy can be obtained.
When printing on low-absorbency paper, the quality of the dot position is noticeable in image quality. In other words, since it is difficult for ink to spread on paper with low absorbency, if the dot position accuracy is as low as possible, a portion where the ink cannot be filled in the paper, that is, a white portion is generated. This portion that cannot be filled up leads to uneven image density and decreased image density, and appears in the degradation of image quality.
However, since the nozzle plate of this embodiment has high dot position accuracy even when using low surface tension ink, the ink can fill the paper even when using paper with low absorbency. A printed matter with high image quality can be obtained without deteriorating.

<Media>
For example, a recording medium (recording medium) used in the present embodiment, such as a dedicated paper for ink jet, has a support and a coating layer on at least one surface of the support. It has the layer of.

In the recording medium, the amount of ink transferred to the recording medium in this embodiment at a contact time of 100 ms measured with a dynamic scanning absorption meter is 4 to 15 ml / m ² , and 6 to 14 ml / m ² is preferred. Further, the transfer amount to the recording medium of the pure water is preferably ^{4~26ml / m 2, 8~25ml / m} 2 is more preferable.
If the transfer amount of the ink and pure water at the contact time of 100 ms is too small, beading is likely to occur. If it is too large, the ink dot diameter after recording becomes too smaller than the desired diameter. There is.
Transfer amount to the recording medium of the ink of the present embodiment in a dynamic scanning absorptometer contact time measured by the meter 400ms is ^{7~20ml / m 2, 8~19ml / m} 2 is preferred. Further, the transfer amount to the recording medium of the pure water is preferably ^{5~29ml / m 2, 10~28ml / m} 2 is more preferable.
If the amount of transfer at the contact time of 400 ms is too small, the drying property is insufficient, and thus spur marks may be easily generated. If the amount is too large, bleeding is likely to occur, and the gloss of the image portion after drying is high. May become low.

  Here, the above-mentioned dynamic scanning absorptometer (DSA, Papa Technical Journal, Vol. 48, May 1994, pp. 88-92, Shigenori Suga) It is a device that can measure accurately. The above dynamic scanning absorption meter reads the absorption speed directly from the movement of the meniscus in the capillary, scans the sample in a disk shape, and then scans the absorption head in a spiral shape. Is automatically changed by a method in which the number of necessary points is measured with one sample. A liquid supply head for a paper sample is connected to a capillary via a Teflon (registered trademark) tube, and the position of the meniscus in the capillary is automatically read by an optical sensor. Specifically, the transfer amount of pure water or ink was measured using a dynamic scanning absorption meter (K350 series D type, manufactured by Kyowa Seiko Co., Ltd.). The transfer amount at the contact time of 100 ms and the contact time of 400 ms can be obtained by interpolation from the measured value of the transfer amount at the contact time adjacent to each contact time. The measurement was performed under conditions of an air temperature of 23 ° C. and a relative humidity of 50% RH.

-Support-
The support is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include paper-based materials such as paper mainly composed of wood fibers, and nonwoven fabrics mainly composed of wood fibers and synthetic fibers. .

  There is no restriction | limiting in particular as said paper, According to the objective, it can select suitably according to the objective, For example, wood pulp, waste paper pulp, etc. are used. Examples of the wood pulp include hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), NBSP, LBSP, GP, and TMP.

  As the raw material for the above-mentioned waste paper pulp, the white paper, ruled white, cream white, card, special white, medium white, imitation, fair white, Kent, white, which are shown in the used paper standard quality specification table of the Waste Paper Recycling Promotion Center, Japan Art, special upper limit, another upper limit, newspaper, magazine, etc. are mentioned. Specifically, printer paper such as non-coating computer paper, thermal paper, and pressure-sensitive paper as information-related paper; OA waste paper such as PPC paper; coating of art paper, coated paper, finely coated paper, matte paper, etc. Paper: High quality paper, color quality, notebook, notepaper, wrapping paper, fancy paper, medium quality paper, newsprint, reprint paper, super paper, imitation paper, pure white roll paper, uncoated paper such as milk carton, etc. Examples of used paper and paperboard include chemical pulp paper and high-yield pulp-containing paper. These may be used individually by 1 type and may use 2 or more types together.

The waste paper pulp is generally produced from a combination of the following four steps.
<1> In disaggregation, waste paper is treated with a mechanical force and chemicals with a pulper to loosen it into a fibrous form, and the printing ink is peeled from the fiber.
<2> Dust removal is performed by removing foreign matter (such as plastic) and dust contained in waste paper with a screen, a cleaner, or the like.
<3> Deinking removes the printing ink peeled off from the fiber using a surfactant by using a flotation method or a cleaning method.
<4> Bleaching increases the whiteness of the fiber using an oxidizing action or a reducing action.
When mixing the used paper pulp, the mixing ratio of the used paper pulp in the total pulp is preferably 40% or less from the viewpoint of curling after recording.

  As the internal filler used for the support, for example, a conventionally known pigment is used as a white pigment. Examples of the white pigment include light calcium carbonate, heavy calcium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, White inorganic pigments such as calcium silicate, magnesium silicate, synthetic silica, aluminum hydroxide, alumina, lithopone, zeolite, magnesium carbonate, magnesium hydroxide; styrene plastic pigment, acrylic plastic pigment, polyethylene, microcapsule, urea resin And organic pigments such as melamine resin. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the internally added sizing agent used for making the support include, for example, neutral rosin sizing agents used for neutral papermaking, alkenyl succinic anhydride (ASA), alkyl ketene dimer (AKD), and petroleum resin. System sizing agents and the like. Among these, a neutral rosin sizing agent or alkenyl succinic anhydride is particularly preferable. The alkyl ketene dimer has a high size effect, so the addition amount may be small, but the friction coefficient on the surface of the recording paper (medium) is low and slippery, which is not preferable from the viewpoint of transportability during ink jet recording. There is.

-Coating layer-
The coating layer contains a pigment and a binder (binder), and further contains a surfactant and other components as necessary.

As the pigment, an inorganic pigment or a combination of an inorganic pigment and an organic pigment can be used.
Examples of the inorganic pigment include kaolin, talc, heavy calcium carbonate, light calcium carbonate, calcium sulfite, amorphous silica, titanium white, magnesium carbonate, titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, Examples thereof include zinc hydroxide and chlorite. Among these, kaolin is particularly preferable because it is excellent in glossiness and can be made close to the paper for offset printing.
The kaolin includes delaminated kaolin, calcined kaolin, engineered kaolin by surface modification, etc. In consideration of gloss development, the particle size distribution with a particle size of 2 μm or less is 80% by mass or more. It is preferable that the kaolin which has occupies 50 mass% or more of the whole kaolin.
The amount of kaolin added is preferably 50 parts by mass or more with respect to 100 parts by mass of the total pigment in the coating layer. When the addition amount is less than 50 parts by mass, a sufficient effect may not be obtained in glossiness. The upper limit of the addition amount is not particularly limited, but is preferably 90 parts by mass or less from the viewpoint of coating suitability in consideration of the fluidity of kaolin, particularly the thickening under high shear force.

Examples of the organic pigment include water-soluble dispersions such as styrene-acrylic copolymer particles, styrene-butadiene copolymer particles, polystyrene particles, and polyethylene particles. Two or more of these organic pigments may be mixed.
The amount of the organic pigment added is preferably 2 to 20 parts by mass with respect to 100 parts by mass of the total pigment in the coating layer. Since the organic pigment is excellent in gloss expression and its specific gravity is smaller than that of an inorganic pigment, it is possible to obtain a coating layer that is bulky, high gloss, and has good surface coverage. When the addition amount is less than 2 parts by mass, the above effect is not obtained. When the addition amount exceeds 20 parts by mass, the fluidity of the coating liquid is deteriorated, leading to a decrease in coating operability, and economical in terms of cost. Not right.
In the form of the organic pigment, there are a solid type, a hollow type, a donut type, and the like, but the average particle size is 0.2 in view of the balance of gloss development, surface coverage, and fluidity of the coating liquid. A hollow mold having a porosity of 40% or more is more preferable.

As the binder, an aqueous resin is preferably used.
As the aqueous resin, at least one of a water-soluble resin and a water-dispersible resin is preferably used. There is no restriction | limiting in particular as said water-soluble resin, According to the objective, it can select suitably, For example, modified products of polyvinyl alcohol, such as polyvinyl alcohol, anion modified polyvinyl alcohol, cation modified polyvinyl alcohol, acetal modified polyvinyl alcohol; Polyurethane; polyvinylpyrrolidone and polyvinylpyrrolidone and vinyl acetate copolymer, vinylpyrrolidone and dimethylaminoethyl / methacrylic acid copolymer, quaternized vinylpyrrolidone / dimethylaminoethyl / methacrylic acid copolymer, vinylpyrrolidone and Modified products of polyvinylpyrrolidone such as a copolymer of methacrylamidopropyl trimethylammonium chloride; Cellulo such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose Modified products of cellulose such as cationized hydroxyethyl cellulose; synthetic resins such as polyesters, polyacrylic acid (esters), melamine resins, or modified products thereof, and copolymers of polyester and polyurethane; poly (meth) acrylic acid, Examples include poly (meth) acrylamide, oxidized starch, phosphate esterified starch, self-modified starch, cationized starch, or various modified starches, polyethylene oxide, sodium polyacrylate, and sodium alginate. These may be used individually by 1 type and may use 2 or more types together.
Among these, polyvinyl alcohol, cation-modified polyvinyl alcohol, acetal-modified polyvinyl alcohol, polyester, polyurethane, a copolymer of polyester and polyurethane, and the like are particularly preferable from the viewpoint of ink absorbability.

There is no restriction | limiting in particular as said water dispersible resin, According to the objective, it can select suitably, For example, polyvinyl acetate, ethylene-vinyl acetate copolymer, polystyrene, styrene- (meth) acrylic acid ester copolymer Polymer, (meth) acrylic acid ester polymer, vinyl acetate- (meth) acrylic acid (ester) copolymer, styrene-butadiene copolymer, ethylene-propylene copolymer, polyvinyl ether, silicone-acrylic copolymer Coalescence, etc. Further, it may contain a crosslinking agent such as methylolated melamine, methylolated urea, methylolated hydroxypropylene urea, or isocyanate, or may be a copolymer containing units such as N-methylolacrylamide and having a self-crosslinking property. A plurality of these water-based resins can be used simultaneously.
2-100 mass parts is preferable with respect to 100 mass parts of said pigments, and, as for the addition amount of the said aqueous resin, 3-50 mass parts is more preferable. The amount of the aqueous resin added is determined so that the liquid absorption characteristics of the recording medium fall within a desired range.

  When a water-dispersible colorant is used as the colorant, the cationic organic compound is not necessarily added, but is not particularly limited and can be appropriately selected and used depending on the purpose. For example, a primary to tertiary amine, quaternary ammonium salt monomer or oligomer that reacts with a sulfonic acid group, a carboxyl group, an amino group, or the like in a direct dye or acidic dye in water-soluble ink to form an insoluble salt. A polymer etc. are mentioned, Among these, an oligomer or a polymer is preferable.

Examples of the cationic organic compound include dimethylamine / epichlorohydrin polycondensate, dimethylamine / ammonia / epichlorohydrin condensate, poly (trimethylaminoethyl methacrylate / methyl sulfate), diallylamine hydrochloride / acrylamide copolymer, poly (Diallylamine hydrochloride / sulfur dioxide), polyallylamine hydrochloride, poly (allylamine hydrochloride / diallylamine hydrochloride), acrylamide / diallylamine copolymer, polyvinylamine copolymer, dicyandiamide, dicyandiamide / ammonium chloride / urea / formaldehyde condensate , Polyalkylene polyamine dicyandiamide ammonium salt condensate, dimethyl diallyl ammonium chloride, polydiallyl methylamine hydrochloride, poly (diallyl dimethyl ester) Ruammonium chloride), poly (diallyldimethylammonium chloride / sulfur dioxide), poly (diallyldimethylammonium chloride / diallylamine hydrochloride derivative), acrylamide / diallyldimethylammonium chloride copolymer, acrylate / acrylamide / diallylamine hydrochloride copolymer Products, ethyleneimine derivatives such as polyethyleneimine and acrylicamine polymer, and polyethyleneimine alkylene oxide modified products. These may be used individually by 1 type and may use 2 or more types together.
Among these, low molecular weight cationic organic compounds such as dimethylamine / epichlorohydrin polycondensate and polyallylamine hydrochloride and other relatively high molecular weight cationic organic compounds such as poly (diallyldimethylammonium chloride) It is preferable to use in combination. By using in combination, the image density is improved and feathering is further reduced as compared with the case of single use.

The cation equivalent of the cationic organic compound by colloid titration method (using polyvinyl potassium sulfate and toluidine blue) is preferably 3 to 8 meq / g. If the cation equivalent is within this range, good results can be obtained within the dry adhesion range.
Here, in the measurement of the cation equivalent by the colloid titration method, the cationic organic compound is diluted with distilled water so that the solid content becomes 0.1% by mass, and the pH is not adjusted.

The dry adhesion amount of the cationic organic compound is preferably 0.3 to 2.0 g / m ² . When the dry adhesion amount of the cationic organic compound is less than 0.3 g / m ² , sufficient image density improvement and feathering reduction effects may not be obtained.

  There is no restriction | limiting in particular as said surfactant, Although it can select suitably according to the objective, Any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant can be used. Of these, nonionic active agents are particularly preferred. By adding the surfactant, the water resistance of the image is improved, the image density is increased, and bleeding is improved.

Examples of the nonionic activator include higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, fatty acid ethylene oxide adduct, polyhydric alcohol fatty acid ester ethylene oxide adduct, higher aliphatic amine ethylene oxide adduct, fatty acid amide. Ethylene oxide adduct, fat ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, fatty acid ester of glycerol, fatty acid ester of pentaerythritol, fatty acid ester of sorbitol and sorbitan, fatty acid ester of sucrose, alkyl ether of polyhydric alcohol, And fatty acid amides of alkanolamines. These may be used individually by 1 type and may use 2 or more types together.
The polyhydric alcohol is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include glycerol, trimethylolpropane, pentaerythritol, sorbitol, and sucrose. As the ethylene oxide adduct, a product obtained by substituting a part of ethylene oxide with an alkylene oxide such as propylene oxide or butylene oxide is also effective as long as water solubility can be maintained. The substitution rate is preferably 50% or less. 4-15 are preferable and, as for HLB (hydrophilic / lipophilic ratio) of the said nonionic active agent, 7-13 are more preferable.

  0-10 mass parts is preferable with respect to 100 mass parts of the said cationic organic compounds, and, as for the addition amount of the said surfactant, 0.1-1.0 mass part is more preferable.

  Other components can be added to the coating layer as necessary, as long as the object and effect of the present invention are not impaired. Examples of the other components include additives such as alumina powder, pH adjuster, preservative, and antioxidant.

There is no restriction | limiting in particular as a formation method of the said coating layer, According to the objective, it can select suitably, It can carry out by the method of impregnating or apply | coating a coating layer liquid on the said support body. The impregnation or coating method of the coating layer solution is not particularly limited and may be appropriately selected depending on the intended purpose. For example, conventional size press, gate roll size press, film transfer size press, blade coater, rod coater It can be applied with various coating machines such as an air knife coater and a curtain coater. Among these, from the viewpoint of cost, a method of impregnating or adhering with a conventional size press, a gate roll size press, a film transfer size press or the like installed in a paper machine and finishing on-machine is preferable.
Adhesion amount of the coating layer liquid is not particularly limited and may be appropriately selected depending on the intended purpose, the solid content is preferably ^{0.5~20g / m 2, 1~15g / m} 2 Gayori preferable.
If it is less than 0.5 g / m ² , the ink cannot be sufficiently absorbed, so that the ink overflows and character bleeding occurs. On the other hand, if it exceeds 20 g / m ² , the texture of the paper is impaired, and it becomes difficult to bend or to write with a writing instrument.
After the above impregnation or coating, drying may be performed as necessary. In this case, the drying temperature is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably about 100 to 250 ° C. .

  The recording medium may further include a back layer on the back surface of the support, another layer between the support and the coating layer, or another layer between the support and the back layer, and a protective layer on the coating layer. Can also be provided. Each of these layers may be a single layer or a plurality of layers.

  The recording medium of the present embodiment may be a commercially available coated paper for offset printing, coated paper for gravure printing, etc. in addition to the ink jet recording medium, as long as the liquid absorption property is within the range of the present embodiment.

The basis weight of the recording medium of the present embodiment is preferably 50 to 250 g / m ² . If it is less than 50 g / m ² , there will be no stiffness, and a conveyance failure such as recording media clogging in the middle of the conveyance path tends to occur. If it exceeds 250 g / m ² , the stiffness becomes too large, and the recording medium cannot be bent at the curved portion in the middle of the conveyance path, and the conveyance failure such as the recording medium being clogged is likely to occur.

<Ink>
The ink of this embodiment contains at least water, a colorant, and a wetting agent, and further contains a penetrating agent, a surfactant, and, if necessary, other components.

The ink has a surface tension at 25 ° C. of 15 to 40 mN / m, and more preferably 20 to 35 mN / m. If the surface tension is less than 15 / m, the nozzle plate of this embodiment is too wet to form ink droplets (particulate), or bleeding on the recording medium of this embodiment becomes significant. Stable ink ejection may not be obtained, and if it exceeds 40 mN / m, ink penetration into the recording medium does not occur sufficiently, and beading may occur and drying time may be prolonged.
Here, the said surface tension can be measured at 25 degreeC using a platinum plate, for example using a surface tension measuring apparatus (Kyowa Interface Science Co., Ltd. product, CBVP-Z).

-Colorant-
As the colorant, it is preferable to use at least one of a pigment, a dye, and colored fine particles.
As the colored fine particles, an aqueous dispersion of fine polymer particles containing at least one of a pigment and a dye is preferably used.
Here, the term “containing a color material” means either or both of a state in which a color material is enclosed in polymer fine particles and a state in which the color material is adsorbed on the surface of the polymer fine particles. In this case, it is not necessary for all of the color material blended in the ink of the present embodiment to be encapsulated or adsorbed in the polymer fine particles, and the color material is dispersed in the emulsion as long as the effect of the present embodiment is not impaired. It may be. The color material is not particularly limited as long as it is water-insoluble or hardly water-soluble and can be adsorbed by the polymer, and can be appropriately selected according to the purpose.
Here, the “water-insoluble or poorly water-soluble” means that the coloring material does not dissolve 10 parts by mass or more with respect to 100 parts by mass of water at 20 ° C. Further, “dissolve” means that separation or sedimentation of the coloring material is not observed on the surface layer or the lower layer of the aqueous solution visually.

The volume average particle diameter of the polymer fine particles (colored fine particles) containing the coloring material is preferably 0.01 to 0.16 μm in the ink.
If it is less than 0.01 μm, the bleeding of the fine particles tends to flow and the light resistance becomes inferior. On the other hand, if it exceeds 0.16 μm, the nozzle is likely to be clogged or the color developability is deteriorated.

Examples of the colorant include water-soluble dyes, oil-soluble dyes, dyes such as disperse dyes, pigments, and the like. Oil-soluble dyes and disperse dyes are preferable from the viewpoint of good adsorptivity and encapsulation, but pigments are preferably used from the light resistance of the obtained image.
The above dyes are preferably dissolved in an organic solvent, for example, a ketone solvent in an amount of 2 g / liter or more, more preferably 20 to 600 g / liter, from the viewpoint of efficiently impregnating the polymer fine particles.
The water-soluble dye is a dye classified into an acid dye, a direct dye, a basic dye, a reactive dye, and a food dye in the color index, and preferably has excellent water resistance and light resistance. .

  Examples of the acid dyes and food dyes include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142; C.I. I. Acid Red 1,8,13,14,18,26,27,35,37,42,52,82,87,89,92,97,106,111,114,115,134,186,249,254 289; I. Acid Blue 9, 29, 45, 92, 249; I. Acid Black 1, 2, 7, 24, 26, 94; I. Food Yellow 3, 4; I. Food red 7, 9, 14; I. Food black 1, 2 etc. are mentioned.

  Examples of the direct dye include C.I. I. Direct yellow 1,12,24,26,33,44,50,86,120,132,142,144; I. Direct red 1,4,9,13,17,20,28,31,39,80,81,83,89,225,227; I. Direct orange 26, 29, 62, 102; I. Direct Blue 1, 2, 6, 15, 22, 25, 71, 76, 79, 86, 87, 90, 98, 163, 165, 199, 202; I. Direct black 19, 22, 32, 38, 51, 56, 71, 74, 75, 77, 154, 168, 171 and the like.

  Examples of the basic dye include C.I. I. Basic yellow 1, 2, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 64, 65, 67, 70, 73, 77, 87, 91; C.I. I. Basic Red 2,12,13,14,15,18,22,23,24,27,29,35,36,38,39,46,49,51,52,54,59,68,69,70, 73, 78, 82, 102, 104, 109, 112; I. Basic blue 1,3,5,7,9,21,22,26,35,41,45,47,54,62,65,66,67,69,75,77,78,89,92,93, 105, 117, 120, 122, 124, 129, 137, 141, 147, 155; I. Basic black 2, 8 etc. are mentioned.

  Examples of the reactive dye include C.I. I. Reactive Black 3, 4, 7, 11, 12, 17; C.I. I. Reactive Yellow 1,5,11,13,14,20,21,22,25,40,47,51,55,65,67; I. Reactive Red 1,14,17,25,26,32,37,44,46,55,60,66,74,79,96,97; I. Reactive blue 1, 2, 7, 14, 15, 23, 32, 35, 38, 41, 63, 80, 95, and the like.

There is no restriction | limiting in particular as said pigment, According to the objective, it can select suitably, For example, any of an inorganic pigment and an organic pigment may be sufficient.
Examples of the inorganic pigment include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, and carbon black. Among these, carbon black is preferable. In addition, as said carbon black, what was manufactured by well-known methods, such as a contact method, a furnace method, and a thermal method, is mentioned, for example.

  Examples of the organic pigment include azo pigments, polycyclic pigments, dye chelates, nitro pigments, nitroso pigments, and aniline black. Among these, azo pigments and polycyclic pigments are more preferable. Examples of the azo pigment include azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments. Examples of the polycyclic pigment include phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinofullerone pigments. Examples of the dye chelates include basic dye chelates and acid dye chelates.

There is no restriction | limiting in particular as a color of the said pigment, According to the objective, it can select suitably, For example, the thing for black, the thing for color, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
Examples of the black color include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11), oxidation, and the like. Examples thereof include metals such as titanium, organic pigments such as aniline black (CI pigment black 1), and the like.

As for the color, for yellow ink, for example, C.I. I. Pigment Yellow 1 (Fast Yellow G), 3, 12 (Disazo Yellow AAA), 13, 14, 17, 23, 24, 34, 35, 37, 42 (Yellow Iron Oxide), 53, 55, 74, 81, 83 (Disazo Yellow HR), 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 138, 150, 153, and the like.
For magenta, for example, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48: 2 (Permanent Red 2B (Ba)), 48: 2 (Permanent Red 2B (Ca)), 48 : 3 (Permanent Red 2B (Sr)), 48: 4 (Permanent Red 2B (Mn)), 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81 (Rhodamine 6G Lake), 83, 88, 92, 101 (Bengara), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (Dimethylquinacridone), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 2 19, etc.
For cyan, for example, C.I. I. Pigment Blue 1, 2, 15 (copper phthalocyanine blue R), 15: 1, 15: 2, 15: 3 (phthalocyanine blue G), 15: 4, 15: 6 (phthalocyanine blue E), 16, 17: 1, 56, 60, 63 and the like.
In addition, as the intermediate colors for red, green and blue, C.I. I. Pigment red 177, 194, 224, C.I. I. Pigment orange 43, C.I. I. Pigment violet 3, 19, 23, 37, C.I. I. Pigment green 7, 36, and the like.

As the pigment, a self-dispersing pigment that can be stably dispersed without using a dispersant in which at least one hydrophilic group is bonded to the surface of the pigment directly or via another atomic group is suitably used. . As a result, unlike the conventional ink, a dispersant for dispersing the pigment becomes unnecessary. As the self-dispersing pigment, those having ionicity are preferable, and those having an anionic charge or those having a cationic charge are suitable.
The volume average particle size of the self-dispersing pigment is preferably 0.01 to 0.16 μm in the ink.

Examples of the anionic hydrophilic group include —COOM, —SO ₃ M, —PO ₃ HM, —PO ₃ M ₂ , —SO ₂ NH ₂ , —SO ₂ NHCOR (wherein M is a hydrogen atom) , R represents an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent). Can be mentioned. Among these, it is preferable to use those in which —COOM and —SO ₃ M are bonded to the surface of the color pigment.

  Further, “M” in the hydrophilic group includes, for example, lithium, sodium, potassium and the like as an alkali metal. Examples of the organic ammonium include mono to trimethyl ammonium, mono to triethyl ammonium, and mono to trimethanol ammonium. As a method of obtaining the above-mentioned anionically charged color pigment, as a method of introducing -COONa to the color pigment surface, for example, a method of oxidizing the color pigment with sodium hypochlorite, a method of sulfonation, a diazonium salt The method of making it react is mentioned.

  As the cationic hydrophilic group, for example, a quaternary ammonium group is preferable, quaternary ammonium groups listed below are more preferable, and any of these bonded to the pigment surface is suitable as a coloring material.

  There is no restriction | limiting in particular as a method of manufacturing the cationic self-dispersion type carbon black to which the said hydrophilic group was couple | bonded, Although it can select suitably according to the objective, For example, N-- represented by following Structural formula Examples of the method for bonding the ethylpyridyl group include a method of treating carbon black with 3-amino-N-ethylpyridinium bromide.

The hydrophilic group may be bonded to the surface of carbon black via another atomic group. Examples of other atomic groups include an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. Specific examples of the case where the above-described hydrophilic group is bonded to the surface of carbon black through another atomic group include, for example, —C ₂ H ₄ COOM (where M represents an alkali metal, quaternary ammonium), -PhSO ₃ M (however, Ph is a phenyl group, M is an alkali metal, represents a quaternary _{ammonium), - C 5 H 10 NH} 3 + , and the like.

In the present embodiment, a pigment dispersion using a pigment dispersant can also be used.
As the pigment dispersant, as the hydrophilic polymer compound, in the natural system, vegetable polymers such as gum arabic, tragan gum, guar gum, karaya gum, locust bean gum, arabinogalactone, pectin, quince seed starch, alginic acid, Examples include seaweed polymers such as carrageenan and agar, animal polymers such as gelatin, casein, albumin and collagen, and microbial polymers such as xanthene gum and dextran. For semi-synthetic systems, cellulose polymers such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, starch polymers such as sodium starch glycolate and sodium starch phosphate, sodium alginate, propylene glycol alginate And seaweed polymers such as Pure synthetic systems include polyvinyl polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyvinyl methyl ether, non-crosslinked polyacrylamide, polyacrylic acid or alkali metal salts thereof, acrylic resins such as water-soluble styrene acrylic resins, and water-soluble styrene malees. Acid resin, water-soluble vinyl naphthalene acrylic resin, water-soluble vinyl naphthalene maleic resin, polyvinyl pyrrolidone, polyvinyl alcohol, alkali metal salts of β-naphthalene sulfonic acid formalin condensate, cationic functional groups such as quaternary ammonium and amino groups Examples thereof include a polymer compound having a salt in the side chain and a natural polymer compound such as shellac. Among these, those having a carboxyl group introduced from a homopolymer of acrylic acid, methacrylic acid or styrene acrylic acid or a copolymer of a monomer having another hydrophilic group are particularly preferred as the polymer dispersant.
The weight average molecular weight of the copolymer is preferably 3,000 to 50,000, more preferably 5,000 to 30,000, and still more preferably 7,000 to 15,000.
The mixing mass ratio of the pigment and the dispersant (pigment: dispersant) is preferably 1: 0.06 to 1: 3, and more preferably 1: 0.125 to 1: 3.

  The amount of the colorant added to the ink is preferably 6 to 15% by mass, and more preferably 8 to 12% by mass. When the addition amount is less than 6% by mass, the image density may be lowered due to a decrease in coloring power, or feathering or bleeding may be deteriorated due to a decrease in viscosity. If the nozzle is left unattended, the nozzles will be easy to dry, non-ejection phenomenon will occur, the viscosity will be too high, the permeability will decrease, and the dots will not spread, so the image density will decrease. Or a blurred image.

-Wetting agent-
There is no restriction | limiting in particular as said wetting agent, According to the objective, it can select suitably, For example, at least 1 sort (s) selected from a polyol compound, a lactam compound, a urea compound, and saccharides is suitable.

  Examples of the polyol compound include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, ethylene carbonate, Etc. These may be used alone or in combination of two or more.

Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,3-purpandiol, 1,3-butanediol, 1,4 butanediol, and 3-methyl- 1,3-butanediol 1,3-propanediol, 1,5-pentanediol, 1,6 hexanediol, glycerol, 1,2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3 -Butanetriol, petriol and the like.
Examples of the polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. It is done.
Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
Examples of the nitrogen-containing heterocyclic compound include N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, and ε-caprolactam.
Examples of the amides include formamide, N-methylformamide, formamide, N, N-dimethylformamide and the like.
Examples of the amines include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, and triethylamine.
Examples of the sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol, and the like.
Among these, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1 from the viewpoint of obtaining excellent effects on solubility and prevention of poor jetting characteristics due to water evaporation , 3-butanediol, 2,3-butanediol, 1,4-butanediol, 3-methyl-1,3-butanediol 1,3-propanediol, 1,5-pentanediol, tetraethylene glycol, 1, 6-hexanediol, 2-methyl-2,4-pentanediol, polyethylene glycol, 1,2,4-butanetriol, 1,2,6-hexanetriol, thiodiglycol, 2-pyrrolidone, N-methyl-2 -Pyrrolidone, N-hydroxyethyl-2-pi Pyrrolidone is preferred.

Examples of the lactam compound include at least one selected from 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, and ε-caprolactam.
Examples of the urea compound include at least one selected from urea, thiourea, ethylene urea, and 1,3-dimethyl-2-imidazolidinone. In general, the amount of urea added to the ink is preferably 0.5 to 50% by mass, and more preferably 1 to 20% by mass.

Examples of the saccharide include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), polysaccharides, and derivatives thereof. Among these, glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, lactose, sucrose, trehalose, and maltotriose are preferable, and maltose, sorbitol, gluconolactone, and maltose are particularly preferable.
The above-mentioned polysaccharide means a saccharide in a broad sense and can be used to include substances widely existing in nature such as α-cyclodextrin and cellulose.
Derivatives of the saccharides include reducing sugars of the saccharides (for example, sugar alcohols (generally represented by HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)) , Oxidized sugars (for example, aldonic acid, uronic acid, etc.), amino acids, thioic acids, etc. Among these, sugar alcohols are particularly preferable, and examples of the alcohol include maltitol, sorbit, and the like.

  10-50 mass% is preferable and, as for content in the said ink of the said wetting agent, 20-35 mass% is more preferable. If the content is too small, the nozzle is likely to be dried and defective ejection of droplets may occur. If the content is too large, the ink viscosity increases and the proper viscosity range may be exceeded.

-Penetration agent-
As the penetrant, a water-soluble organic solvent such as a polyol compound or a glycol ether compound is used. In particular, at least one of a polyol compound having 8 or more carbon atoms and a glycol ether compound is preferably used.
When the polyol compound has less than 8 carbon atoms, sufficient permeability cannot be obtained, and the recording medium is soiled during double-sided printing, or ink spreading on the recording medium is insufficient, resulting in poor pixel filling. Therefore, character quality and image density may be reduced.
Examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol (solubility: 4.2% (25 ° C.)), 2,2,4-trimethyl-1,3-pentanediol. (Solubility: 2.0% (25 ° C.)) is preferable.

  The glycol ether compound is not particularly limited and may be appropriately selected depending on the intended purpose.For example, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, Examples include polyhydric alcohol alkyl ethers such as tetraethylene glycol monomethyl ether and propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

  There is no restriction | limiting in particular in the addition amount of the said penetrant, Although it can select suitably according to the objective, 0.1-20 mass% is preferable and 0.5-10 mass% is more preferable.

-Surfactant-
There is no restriction | limiting in particular as said surfactant, According to the objective, it can select suitably, For example, anionic surfactant, nonionic surfactant, amphoteric surfactant, fluorine type surfactant etc. are mentioned. .

  Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.

Examples of the nonionic surfactant include acetylene glycol surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, and the like.
Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, , 5-dimethyl-1-hexyn-3-ol and the like. Examples of commercially available acetylene glycol surfactants include Surfynol 104, 82, 465, 485, and TG manufactured by Air Products and Chemicals (USA).

  Examples of the amphoteric surfactant include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine. Specific examples include lauryl dimethylamine oxide, myristyl dimethylamine oxide, stearyl dimethylamine oxide, dihydroxyethyl lauryl amine oxide, polyoxyethylene coconut oil alkyl dimethyl amine oxide, dimethyl alkyl (coconut) betaine, dimethyl lauryl betaine, and the like. It is done.

  Among these surfactants, surfactants represented by the following general formulas (I), (II), (III), (IV), (V), and (VI) are preferable.

R ¹ —O— (CH ₂ CH ₂ O) _h CH ₂ COOM —General Formula (I)
However, in the said general formula (I), R1 represents an alkyl group and represents the C6-C14 alkyl group which may be branched. h represents an integer of 3 to 12. M represents one selected from alkali metal ions, quaternary ammonium, quaternary phosphonium, and alkanolamine.

ただし、上記一般式（ＩＩ）中、Ｒ２は、アルキル基を表し、炭素数５〜１６の分岐していてもよいアルキル基を表す。Ｍは、アルカリ金属イオン、第４級アンモニウム、第４級ホスホニウム、及びアルカノールアミンから選択されるいずれかを表す。

However, in said general formula (II), R2 represents an alkyl group and represents the C5-C16 alkyl group which may be branched. M represents one selected from alkali metal ions, quaternary ammonium, quaternary phosphonium, and alkanolamine.

ただし、上記一般式（ＩＩＩ）中、Ｒ３は、炭化水素基を表し、例えば、分岐していてもよい炭素数６〜１４のアルキル基を表す。ｋは５〜２０の整数を表す。
Ｒ⁴−（ＯＣＨ₂ＣＨ₂）_jＯＨ ・・・一般式（ＩＶ）
ただし、上記一般式（ＩＶ）中、Ｒ４は、炭化水素基を表し、例えば、炭素数６〜１４のアルキル基を表す。ｊは、５〜２０の整数を表す。

However, in said general formula (III), R3 represents a hydrocarbon group, for example, the C6-C14 alkyl group which may be branched. k represents an integer of 5 to 20.
R ⁴ — (OCH ₂ CH ₂ ) _j OH —General formula (IV)
However, in said general formula (IV), R4 represents a hydrocarbon group, for example, a C6-C14 alkyl group. j represents an integer of 5 to 20.

ただし、上記一般式（Ｖ）中、Ｒ６は、炭化水素基を表し、例えば、炭素数６〜１４の分岐していてもよいアルキル基を表す。Ｌ及びｐは、１〜２０の整数を表す。

However, in said general formula (V), R6 represents a hydrocarbon group, for example, the C6-C14 alkyl group which may be branched. L and p represent an integer of 1 to 20.

ただし、上記一般式（ＶＩ）中、ｑ及びｒは０〜４０の整数を表す。

However, in said general formula (VI), q and r represent the integer of 0-40.

Hereinafter, the surfactants of the above structural formulas (I) and (II) are specifically shown in free acid form.
(I-1): CH ₃ (CH ₂ ) ₁₂ O (CH ₂ CH ₂ O) ₃ CH ₂ COOH
(I-2): CH ₃ (CH ₂ ) ₁₂ O (CH ₂ CH ₂ O) ₄ CH ₂ COOH
(I-3): CH ₃ (CH ₂ ) ₁₂ O (CH ₂ CH ₂ O) ₅ CH ₂ COOH
(I-4): CH ₃ (CH ₂ ) ₁₂ O (CH ₂ CH ₂ O) ₆ CH ₂ COOH

As the fluorosurfactant, those represented by the following general formula (A) are suitable.
CF ₃ CF ₂ (CF ₂ CF ₂ ) _m —CH ₂ CH ₂ O (CH ₂ CH ₂ O) _n H —General formula (A)
However, in said general formula (A), m represents the integer of 0-10. n represents an integer of 1 to 40.

  Examples of the fluorosurfactant include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic compounds, perfluoroalkyl phosphate compounds, perfluoroalkyl ethylene oxide adducts, and perfluoroalkyl ether groups in the side chain. And polyoxyalkylene ether polymer compounds. Among these, the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain has a low foaming property, and the bioaccumulation property of a fluorine compound that has been regarded as a problem in recent years is low and highly safe. Particularly preferred.

Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like.
Examples of the perfluoroalkyl carboxylic compounds include perfluoroalkyl carboxylic acids and perfluoroalkyl carboxylic acid salts.
Examples of the perfluoroalkyl phosphate compound include perfluoroalkyl phosphate esters, perfluoroalkyl phosphate salts, and the like.
The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain, and a polyoxyalkylene ether having a perfluoroalkyl ether group in the side chain. Examples thereof include a sulfate salt of a polymer and a salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain.
As counter ions of the salts in these fluorosurfactants, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) ₃ etc.

As said fluorosurfactant, what was synthesize | combined suitably may be used and a commercial item may be used.
As this commercial item, for example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.), Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited), MegaFuck F-470, F1405, F -474 (all manufactured by Dainippon Ink & Chemicals, Inc.), Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all manufactured by DuPont), FT- 110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), PF-151N (Omnova Solutions). Among these, Zonyl FS-300, FSN, FSN-100, and FSO (manufactured by DuPont) are particularly preferable from the viewpoints of reliability and color development improvement.

-Other ingredients-
There is no restriction | limiting in particular as said other components, It can select suitably as needed, For example, resin emulsion, pH adjuster, antiseptic / antifungal agent, rust preventive agent, antioxidant, ultraviolet absorber, oxygen An absorber, a light stabilizer, etc. are mentioned.

-Resin emulsion-
The resin emulsion is obtained by dispersing resin fine particles in water as a continuous phase, and may contain a dispersant such as a surfactant as necessary.
The content of resin fine particles as the dispersed phase component (content of resin fine particles in the resin emulsion) is generally preferably 10 to 70% by mass. Further, the particle diameter of the resin fine particles is preferably 10 to 1000 nm, more preferably 20 to 300 nm, particularly considering use in an ink jet recording apparatus.

The resin fine particle component of the dispersed phase is not particularly limited and may be appropriately selected depending on the intended purpose. For example, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene-butadiene resin , Vinyl chloride resins, acrylic styrene resins, acrylic silicone resins, and the like. Among these, acrylic silicone resins are particularly preferable.
As said resin emulsion, what was synthesize | combined suitably may be used and a commercial item may be used.
Examples of the commercially available resin emulsion include Microgel E-1002, E-5002 (styrene-acrylic resin emulsion, manufactured by Nippon Paint Co., Ltd.), and Boncoat 4001 (acrylic resin emulsion, manufactured by Dainippon Ink & Chemicals, Inc.). ), Boncoat 5454 (styrene-acrylic resin emulsion, manufactured by Dainippon Ink & Chemicals, Inc.), SAE-1014 (styrene-acrylic resin emulsion, manufactured by Nippon Zeon Co., Ltd.), Cybinol SK-200 (acrylic resin emulsion, Seiden Chemical Co., Ltd.), Primal AC-22, AC-61 (acrylic resin emulsion, manufactured by Rohm and Haas Company), Nanocryl SBCX-2821, 3689 (acrylic silicone resin emulsion, Toyo Manufactured Nki Manufacturing Co.), # 3070 (methyl methacrylate polymer resin emulsion, manufactured by Mikuni Color Ltd.).

  The addition amount of the resin fine particle component in the resin emulsion in the ink is preferably 0.1 to 50% by mass, more preferably 0.5 to 20% by mass, and still more preferably 1 to 10% by mass. When the addition amount is less than 0.1% by mass, the effect of improving clogging resistance and ejection stability may not be sufficient, and when it exceeds 50% by mass, the storage stability of the ink may be reduced. There is.

  Examples of the antiseptic / antifungal agent include 1,2-benzisothiazolin-3-one, sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, and sodium pentachlorophenol. Can be mentioned.

The pH adjusting agent is not particularly limited as long as the pH can be adjusted to 7 or more without adversely affecting the ink, and any substance can be used according to the purpose.
Examples of the pH adjusting agent include amines such as diethanolamine and triethanolamine, hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide and potassium hydroxide; ammonium hydroxide and quaternary ammonium hydroxide. And quaternary phosphonium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate.

  Examples of the antirust agent include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite, and the like.

Examples of the antioxidant include phenolic antioxidants (including hindered phenolic antioxidants), amine-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants.
Examples of the phenolic antioxidants (including hindered phenolic antioxidants) include butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, and stearyl-β- (3.5). -Di-tert-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-Butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) ) Propionyloxy] ethyl] 2,4,8,10-tetrixaspiro [5,5] undecane, 1,1,3-tris (2-methyl-4- Hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane, and the like.
Examples of the amine-based antioxidant include phenyl-β-naphthylamine, α-naphthylamine, N, N′-di-sec-butyl-p-phenylenediamine, phenothiazine, N, N′-diphenyl-p-phenylenediamine. 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butyl-phenol, butylhydroxyanisole, 2,2′-methylenebis ( 4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), tetrakis [methylene -3 (3,5-di-tert-butyl-4-dihydroxyphenyl) propionate] methane, 1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, and the like.
Examples of the sulfur-based antioxidant include dilauryl 3,3′-thiodipropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, dimyristyl 3,3′-thiodipropionate, and distearyl β. , β′-thiodipropionate, 2-mercaptobenzimidazole, dilauryl sulfide and the like.
Examples of the phosphorus antioxidant include triphenyl phosphite, octadecyl phosphite, triisodecyl phosphite, trilauryl trithiophosphite, and trinonylphenyl phosphite.

Examples of the UV absorber include benzophenone UV absorbers, benzotriazole UV absorbers, salicylate UV absorbers, cyanoacrylate UV absorbers, nickel complex salt UV absorbers, and the like.
Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2,4-dihydroxybenzophenone, and 2-hydroxy-4-methoxybenzophenone. 2,2 ′, 4,4′-tetrahydroxybenzophenone, and the like.
Examples of the benzotriazole-based ultraviolet absorber include 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-4′-octoxyphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, and the like.
Examples of the salicylate-based ultraviolet absorber include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, and the like.
Examples of the cyanoacrylate ultraviolet absorber include ethyl-2-cyano-3,3′-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate, and butyl-2- And cyano-3-methyl-3- (p-methoxyphenyl) acrylate.
Examples of the nickel complex salt ultraviolet absorber include nickel bis (octylphenyl) sulfide, 2,2′-thiobis (4-tert-octylferrate) -n-butylamine nickel (II), 2,2′-thiobis. (4-tert-octyl ferrate) -2-ethylhexylamine nickel (II), 2,2′-thiobis (4-tert-octyl ferrate) triethanolamine nickel (II), and the like.

  The ink in the ink media set of the present embodiment disperses or dissolves at least water, a colorant, and a wetting agent, if necessary, a penetrating agent, a surfactant, and, if necessary, other components in an aqueous medium, Furthermore, it stirs and mixes as needed. The dispersion can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, and the like. be able to.

The viscosity of the ink is preferably 1 cps (centipoise) to 30 cps, more preferably 2 to 20 cps at 25 ° C. If the viscosity exceeds 20 cps, it may be difficult to ensure ejection stability.
The pH of the ink is preferably 7 to 10, for example.

  There is no restriction | limiting in particular as coloring of the said ink, According to the objective, it can select suitably, Yellow, magenta, cyan, black etc. are mentioned. When recording is performed using an ink set in which two or more of these colorings are used in combination, a multicolor image can be formed. When recording is performed using an ink set in which all colors are combined, a full color image is formed. be able to.

<Example>

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

[Preparation Example 1]
-Preparation of copper phthalocyanine pigment-containing polymer fine particle dispersion-
After sufficiently replacing the inside of the 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas introduction tube, reflux tube, and dropping funnel with nitrogen gas, 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate Then, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer (manufactured by Toa Gosei Co., Ltd., trade name: AS-6) and 0.4 g of mercaptoethanol were charged and heated to 65 ° C. Next, 100.8 g of styrene, 25.2 g of acrylic acid, 108.0 g of lauryl methacrylate, 36.0 g of polyethylene glycol methacrylate, 60.0 g of hydroxyethyl methacrylate, styrene macromer (trade name: AS-6, manufactured by Toagosei Co., Ltd.) A mixed solution of 36.0 g, mercaptoethanol 3.6 g, azobisdimethylvaleronitrile 2.4 g, and methyl ethyl ketone 18 g was dropped into the flask over 2.5 hours.
After completion of dropping, a mixed solution of 0.8 g of azobisdimethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 g of azobisdimethylvaleronitrile was added and further aging was performed for 1 hour. After completion of the reaction, 364 g of methyl ethyl ketone was added to the flask to obtain 800 g of a polymer solution having a concentration of 50% by mass. Next, a part of the polymer solution was dried and measured by gel permeation chromatography (standard: polystyrene, solvent: tetrahydrofuran). The weight average molecular weight (Mw) was 15,000.

Next, 28 g of the obtained polymer solution, 26 g of copper phthalocyanine pigment, 13.6 g of 1 mol / L potassium hydroxide aqueous solution, 20 g of methyl ethyl ketone, and 30 g of ion-exchanged water were sufficiently stirred. Thereafter, the mixture was kneaded 20 times using a three-roll mill (manufactured by Noritake Company, trade name: NR-84A). The obtained paste was put into 200 g of ion-exchanged water, and after sufficiently stirring, methyl ethyl ketone and water were distilled off using an evaporator to obtain 160 g of a blue polymer fine particle dispersion having a solid content of 20.0% by mass. .
About the obtained polymer microparticles | fine-particles, the average particle diameter (D50%) measured with the particle size distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was 93 nm.

[Preparation Example 2]
-Preparation of dimethylquinacridone pigment-containing polymer fine particle dispersion-
In Preparation Example 1, the copper phthalocyanine pigment was changed to C.I. I. A red-purple polymer fine particle dispersion was prepared in the same manner as in Preparation Example 1, except that the pigment red 122 was used.
About the obtained polymer fine particle, the average particle diameter (D50%) measured with the particle size distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was 127 nm.

[Preparation Example 3]
-Preparation of monoazo yellow pigment-containing polymer fine particle dispersion-
In Preparation Example 1, the copper phthalocyanine pigment was changed to C.I. I. A yellow polymer fine particle dispersion was prepared in the same manner as in Preparation Example 1, except that the pigment yellow 74 was changed.
About the obtained polymer microparticles | fine-particles, the average particle diameter (D50%) measured with the particle size distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was 76 nm.

[Preparation Example 4]
-Preparation of carbon black dispersion treated with sulfonating agent-
150 g of commercially available carbon black pigment (manufactured by Degussa, “Printex # 85”) was mixed well into 400 ml of sulfolane, finely dispersed with a bead mill, 15 g of amidosulfuric acid was added, and the mixture was stirred at 140 to 150 ° C. for 10 hours. The obtained slurry was put into 1000 ml of ion-exchanged water, and a surface-treated carbon black wet cake was obtained with a centrifuge at 12,000 rpm. The obtained carbon black wet cake is redispersed in 2,000 ml of ion exchange water, adjusted to pH with lithium hydroxide, desalted and concentrated with an ultrafiltration membrane, and a carbon black dispersion having a pigment concentration of 10% by mass. And filtering with a nylon filter having an average pore diameter of 1 μm to obtain a carbon black dispersion.
About the obtained carbon black dispersion, the average particle diameter (D50%) measured with the particle size distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was 80 nm.

[Production Example 1]
-Production of cyan ink-
Copper phthalocyanine pigment-containing polymer fine particle dispersion 20.0% by mass of Preparation Example 1, 3-methyl-1,3-butanediol 23.0% by mass, glycerin 8.0% by mass, 2-ethyl-1,3-hexane 2.0% by mass of diol, 2.5% by mass of FS-300 (manufactured by DuPont) as a fluorosurfactant, 0.2% by mass of Proxel LV (manufactured by Avecia) as antiseptic / antifungal agent, 2- A suitable amount of amino-2-ethyl-1,3-propanediol 0.5% by mass and ion-exchanged water was added to make 100% by mass, followed by filtration with a membrane filter having an average pore size of 0.8 μm. A cyan ink was prepared as described above.

[Production Example 2]
-Magenta ink production-
Dimethylquinacridone pigment-containing polymer fine particle dispersion 20.0% by mass of Preparation Example 2, 3-methyl-1,3-butanediol 22.5% by mass, glycerin 9.0% by mass, 2-ethyl-1,3-hexane 2.0% by mass of diol, 2.5% by mass of FS-300 (manufactured by DuPont) as a fluorosurfactant, 0.2% by mass of Proxel LV (manufactured by Avecia) as antiseptic / antifungal agent, 2- A suitable amount of amino-2-ethyl-1,3-propanediol 0.5% by mass and ion-exchanged water was added to 100% by mass, and then filtered through a membrane filter having an average pore size of 0.8 μm. A magenta ink was prepared as described above.

[Production Example 3]
-Preparation of yellow ink-
Monoazo yellow pigment-containing polymer fine particle dispersion of Preparation Example 2 20.0% by mass, 3-methyl-1,3-butanediol 24.5% by mass, glycerin 8.0% by mass, 2-ethyl-1,3-hexane 2.0% by mass of diol, 2.5% by mass of FS-300 (manufactured by DuPont) as a fluorosurfactant, 0.2% by mass of Proxel LV (manufactured by Avecia) as antiseptic / antifungal agent, 2- A suitable amount of amino-2-ethyl-1,3-propanediol 0.5% by mass and ion-exchanged water was added to make 100% by mass, followed by filtration with a membrane filter having an average pore size of 0.8 μm. Thus, a yellow ink was prepared.

[Production Example 4]
-Preparation of black ink-
Carbon black dispersion of Preparation Example 4 20.0% by mass, 2-methyl-1,3-butanediol 22.5% by mass, glycerin 7.5% by mass, 2-pyrrolidone 2.0% by mass, 2-ethyl- 2.0% by mass of 1,3-hexanediol, 2.5% by mass of FS-300 (manufactured by DuPont) as a fluorosurfactant, and Proxel LV (manufactured by Avecia) as an antiseptic / antifungal agent 0.2 Add an appropriate amount of mass%, 2-amino-2-ethyl-1,3-propanediol 0.5 mass%, and ion exchange water to 100 mass%, and then filter with a membrane filter having an average pore diameter of 0.8 μm. went. A black ink was prepared as described above.

  Next, the surface tension and viscosity of each of the inks of Production Examples 1 to 4 obtained were measured as follows. The results are shown in Table 3.

<Measurement of viscosity>
The viscosity was measured at 25 ° C. using a R-500 viscometer (manufactured by Toki Sangyo Co., Ltd.) under conditions of cone 1 ° 34 ′ × R24, 60 rpm, 3 minutes later.

<Measurement of surface tension>
The surface tension is a static surface tension measured at 25 ° C. using a platinum plate using a surface tension measuring device (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

-Production of support-
A 0.3 mass% slurry having the following composition was made with a long paper machine to prepare a support having a basis weight of 79 g / m ² . In the size press process of the papermaking process, the oxidized starch aqueous solution was applied so that the solid content was 1.0 g / m ² per side.
-Hardwood bleached kraft pulp (LBKP): 80 parts by mass-Softwood bleached kraft pulp (NBKP): 20 parts by mass-Light calcium carbonate (trade name: TP-121, manufactured by Okutama Kogyo Co., Ltd.) ... 10 Part by mass-Aluminum sulfate-1.0 part by mass-Amphoteric starch (trade name: Cato3210, manufactured by NSC Japan)-1.0 part by weight-Neutral rosin sizing agent (trade name: NeuSize M-10) , Produced by Harima Chemicals Co., Ltd.) ... 0.3 parts by mass Yield improver (trade name: NR-11LS, produced by Hymo Co., Ltd.) ... 0.02 parts by mass

[Production Example 5]
-Production of recording medium 1-
70 parts by mass of clay having a particle diameter of 2 μm or less as a pigment of 97% by mass, 30 parts by mass of heavy calcium carbonate having an average particle diameter of 1.1 μm, and styrene having a glass transition temperature (Tg) of −5 ° C. as an adhesive -Add 8 parts by weight of butadiene copolymer emulsion, 1 part by weight of phosphate esterified starch, and 0.5 parts by weight of calcium stearate as an auxiliary agent, and then add water to obtain a coating solution having a solid content concentration of 60% by weight. Prepared.
The obtained coating liquid is applied to both sides using a blade coater so that the solid content per side is 8 g / m ² on the prepared support, dried with hot air, and then subjected to a step super calender treatment. As a result, “Recording medium 1” was produced.

[Production Example 6]
-Production of recording medium 2-
70 parts by mass of clay having a particle diameter of 2 μm or less as a pigment of 97% by mass, 30 parts by mass of heavy calcium carbonate having an average particle diameter of 1.1 μm, and styrene having a glass transition temperature (Tg) of −5 ° C. as an adhesive -Addition of 7 parts by mass of butadiene copolymer emulsion, 0.7 parts by mass of phosphoric acid esterified starch, 0.5 parts by mass of calcium stearate as an auxiliary agent, and further water to add a coating solution having a solid content concentration of 60% by mass Was prepared.
The obtained coating solution is coated on both sides with a blade coater so that the solid content per side is 8 g / m ² on the prepared support, dried with hot air, and then subjected to a step super calendar process. "Recording medium 2" was produced.

[Example 1]
-Ink set, recording media, and image recording-
“Ink set 1” consisting of black ink of Production Example 4, yellow ink of Production Example 3, magenta ink of Production Example 2 and cyan ink of Production Example 1 was prepared by a conventional method.
Using the obtained ink set 1 and the recording medium 1 described above, printing is performed at an image resolution of 600 dpi and a maximum ink droplet of 18 pl using a drop-on-demand printer prototype having 300 dpi, nozzle resolution 384, and nozzles. It was. The amount of secondary color was regulated to 140% and the amount of adhesion was regulated, and solid images and characters were printed to obtain an image print.

[Example 2]
-Ink set, recording media, and image recording-
In Example 1, except that the recording medium 2 was used as a recording medium, printing was performed in the same manner as in Example 1 to obtain an image print.

Example 3
-Ink set, recording media, and image recording-
In Example 1, a gravure coated paper (trade name; space DX, basis weight = 56 g / m ² , manufactured by Nippon Paper Industries Co., Ltd.) (hereinafter referred to as “recording medium 3”) was used as the recording medium. Except for the above, printing was performed in the same manner as in Example 1 to obtain an image print.

[Comparative Example 1]
-Ink set, recording media, and image recording-
In Example 1, a commercially available offset coated paper (trade name: Aurora coat, basis weight = 104.7 g / m2, manufactured by Nippon Paper Industries Co., Ltd., hereinafter referred to as “recording medium 4”) is used as the recording medium. Except that, printing was performed in the same manner as in Example 1 to obtain an image print.

[Comparative Example 2]
-Ink set, recording media, and image recording-
In Example 1, except that commercially available matte coated paper for inkjet (trade name: Superfine exclusive paper, manufactured by Seiko Epson Corporation, hereinafter referred to as “recording medium 5”) was used as the recording medium. In the same manner as in Example 1, printing was carried out to obtain an image print.

  Next, for the recording medium 1, the recording medium 2, the recording medium 3, the recording medium 4, and the recording medium 5, the pure water by the dynamic scanning absorption meter and the cyan ink of Production Example 1 were used as follows. The amount of transfer was measured. The results are shown in Table 4.

<Measurement of transfer amount of pure water and cyan ink by dynamic scanning absorption meter>
Using a dynamic scanning absorption meter (K350 series D type, manufactured by Kyowa Seiko Co., Ltd.) for each recording medium, the transfer amount of pure water or cyan ink at a temperature of 25 ° C. and a relative humidity of 50% RH Was measured. The transfer amount at the contact time of 100 ms and the contact time of 400 ms was determined by interpolation from the measured value of the transfer amount at the contact time adjacent to each contact time.

  Next, for each of the obtained image prints of Examples 1 to 5 and Comparative Examples 1 and 2, beading, bleeding, spur marks, and gloss were evaluated as follows. The results are shown in Table 5.

<Beading>
The degree of beading of the green solid image portion of each image print was visually observed and evaluated according to the following criteria.
"Evaluation criteria"
Rank 4: There is no occurrence of beading and uniform printing.
Rank 3: Slight beading is observed.
Rank 2: The occurrence of beading is clearly recognized.
Rank 1: Significant beading is observed.

<Evaluation of bleed>
The degree of bleed of black letters in the yellow of each image print was visually observed and evaluated according to the following criteria.
"Evaluation criteria"
A: Clear printing without bleeding.
○: Slight bleeding is observed.
X: The blur has occurred so that the outline of the character is not clear.

<Evaluation of spur marks>
The degree of spurs on each image print was visually observed and evaluated according to the following criteria.
"Evaluation criteria"
A: Not recognized at all.
○: Slightly recognized.
×: Spur marks are clearly recognized.

<Evaluation of glossiness>
The 60 ° specular gloss (JIS Z8741) of the cyan solid image portion of each image print was measured.

From the results shown in Table 5, at least a water, a colorant, and a wetting agent are contained, and an ink having a surface tension at 25 ° C. of 20 to 35 mN / m and a contact time of 100 ms measured with a dynamic scanning absorption meter. a recording transfer amount is 4~15ml / m ² to the media of the ink, and transfer amount of the recording medium of the ink at a contact time of 400ms is a combination of a recording medium is 7~20ml / m ² In Examples 1 to 3, it was confirmed that the evaluation results for achieving beading suppression, bleed suppression, no spur trace, and high glossiness at a high level at the same time were obtained as compared with Comparative Examples 1 and 2.

The above-described embodiment is a preferred embodiment of the present invention, and the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.
For example, although the nozzle plate 2 has been described as being made of Ni electroforming, various types of metals such as SUS (Super Use Stainless) may be used as long as the material of the ink repellent film can be applied, and various types of resins can be used. It may be.

In forming the ink repellent film on the substrate surface of the inkjet head, the oxide film on the surface of the substrate (nozzle plate 2) may be first removed and then the ink repellent film material may be applied to form an intermediate layer. After that, a material for the ink repellent film may be applied.
As this intermediate layer (primer), for example, “Primer D” manufactured by Toray Dow Corning Co., Ltd. can be used, and it has been confirmed that the adhesiveness is also good.
Further, the ink repellent film material may be applied after roughening the base of the substrate surface by Ni strike plating or the like.

It is sectional drawing of the inkjet head nozzle plate used for this embodiment. It is a figure explaining the shape characteristic of this sectional view. It is a figure explaining the shape characteristic of a comparative example. It is a figure which shows the structure which forms the ink repellent film 1 by application | coating using the dispenser 4 which concerns on this embodiment. (A) This embodiment, (b) General, It is a figure which shows the relationship between each needle tip shape and application | coating operation | movement. It is a figure which shows the operation | movement which forms the ink repellent film | membrane 1 using the dispenser 4 which concerns on this embodiment. FIG. 3 is a cross-sectional view of an ink jet head nozzle plate when an ink repellent film 1a on an inner wall of an opening and an ink repellent film 1 on an ink ejection surface are formed. It is sectional drawing of the conventional inkjet head nozzle plate containing a sharp end in the edge part vicinity of an opening part.

Explanation of symbols

1 Ink repellent film (for example, silicone resin film)
2 Nozzle plate (for example, made of Ni)
3 ink 4 dispenser (syringe)
5 Needle 6 Gas 7 Wiper

Claims (16)

An ink-repellent film is formed on the substrate surface of the inkjet head in which an opening for liquid ejection is opened, and a cross-sectional area in a plane perpendicular to the center line of the opening in the vicinity of the opening of the ink-repellent film is A method of recording with ink ejected from an inkjet head formed so as to gradually increase with distance from the substrate surface,
Under the conditions of an air temperature of 23 ° C. and a relative humidity of 50% RH, the transfer amount of the ink to the recording medium at a contact time of 100 ms is 4 to 15 ml / m ² , and the ink is transferred to the recording medium at a contact time of 400 ms. A recording method comprising recording on a recording medium having a transfer amount of 7 to 20 ml / m ² . The recording medium has a pure water transfer rate of 4 to 26 ml / m ² at a contact time of 100 ms under a temperature of 23 ° C. and a relative humidity of 50% RH, and a contact time of 400 ms. The recording method according to claim 1, wherein the amount of transfer to the recording medium is 5 to 29 ml / m ² .   The recording method according to claim 1, wherein the recording medium is a recording medium having a support and a coating layer provided on at least one surface of the support. The recording medium is composed of at least a substrate and a coating layer, and the solid content adhesion amount of the coating layer is 0.5 to 20.0 g / m ^2. 4. The recording method according to any one of items 3. The recording method according to claim 1, wherein the recording medium has a basis weight of 50 to 250 g / m ² .   6. The recording method according to claim 1, wherein the recording medium is subjected to a super calendar process.   The recording method according to claim 1, wherein the recording medium contains a pigment, and the pigment is kaolin.   The recording method according to claim 1, wherein the recording medium contains a pigment, and the pigment is heavy calcium carbonate.   The recording method according to claim 1, wherein the recording medium contains an aqueous resin.   The recording method according to claim 9, wherein the aqueous resin is a water-soluble resin or a water-dispersible resin.   The recording method according to claim 1, wherein the ink contains at least water, a colorant, and a wetting agent.   The recording method according to claim 1, wherein the ink has a surface tension at 25 ° C. of 15 to 40 mN / m.   13. The ink according to claim 1, wherein the ink contains a dispersible colorant as a colorant, and the average particle diameter of the dispersible colorant is 0.01 to 0.16 μm. Recording method.   The recording method according to any one of claims 1 to 13, wherein the ink has a viscosity of 1 to 30 cps at 25 ° C.   The recording method according to claim 1, wherein the ink contains a surfactant, and the surfactant is a fluorosurfactant. An ink-repellent film is formed on the substrate surface of the inkjet head in which an opening for liquid ejection is opened, and a cross-sectional area in a plane perpendicular to the center line of the opening in the vicinity of the opening of the ink-repellent film is By the ink ejected from the inkjet head formed so as to gradually increase as it moves away from the substrate surface,
Under the conditions of an air temperature of 23 ° C. and a relative humidity of 50% RH, the transfer amount of the ink to the recording medium at a contact time of 100 ms is 4 to 15 ml / m ² , and the ink is transferred to the recording medium at a contact time of 400 ms. A printed matter recorded on a recording medium having a transfer amount of 7 to 20 ml / m ² .

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