JP2002309143A - Water-base fluorescent ink, recording unit, ink cartridge, ink jet recording apparatus, and ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-base fluorescent ink which emits stable fluorescence and is excellent in deliverability in ink jet recording; and a recording unit, an ink cartridge, an ink jet recording apparatus, and an ink jet recording method wherewith a high image quality can be stably obtained and a fluorescent image excellent in image fastness can be obtained. SOLUTION: This water-base fluorescent ink for ink jet contains an emulsion of a resin colored with a fluorescent dye and a water-soluble compound which is solid at 25 deg.C and has ethylene oxide units. The recording unit has an ink container for containing the ink and an ink jet head for delivering the ink. The ink cartridge is for containing the ink. The ink jet recording apparatus has an ink-containing section for containing the ink and an ink jet head for delivering the ink. The ink jet recording method contains the step of delivering the ink by an ink jet method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based fluorescent ink for ink-jet recording, in which ink is ejected by thermal energy for recording, an ink cartridge using the ink, a recording unit, an ink-jet recording apparatus, and an ink-jet recording method.

[0002]

2. Description of the Related Art Conventionally, fluorescent coloring materials have been used for line marker pens and the like. More recently, inks using fluorescent pigments have also appeared in order to improve the robustness. For example, JP-A-6-346013 and JP-A-5-239395 disclose fluorescent pigment inks for writing implements using organic fluorescent pigments.

[0003] In addition to the above-mentioned use as a writing instrument, the fluorescent ink is also used for printing a digital watermark or a seal for a postal item to be paid separately.

The use of an ink jet printer for these prints is disclosed in Japanese Patent Application Laid-Open No. 9-291246. In this publication, in a water-resistant ink composition using a soluble toner, H.I. L. B. (Hy
drofileLipophileBalance)
Discloses that 8 to 15 nonionic surfactants are used as solubilizers.

In the printing of digital watermarks and postal indicia, when using the fluorescence intensity of these printed materials as a threshold value, it is important to emit stable fluorescence. However, depending on the above prior art, there was a case where stable fluorescence intensity could not be obtained.

Further, in ink jet recording (called a bubble jet) in which ink is jetted by thermal energy to perform recording, it is necessary to stabilize foaming for ink ejection in order to perform stable ink ejection. At this point, the above inks were not yet sufficient.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous fluorescent ink which emits stable fluorescence and has excellent ink discharge properties when used for ink jet recording, especially for bubble jet recording. Further, the present invention provides a recording unit, an ink cartridge, an ink jet recording apparatus, and an ink jet recording method capable of stably obtaining high-quality image quality due to excellent ink ejection property and obtaining a fluorescent image having excellent image fastness. Is to do.

[0008]

The above object is achieved by the present invention described below.

That is, the present invention provides an emulsion of a resin colored with a fluorescent dye and a solid at 25 ° C.
A water-soluble compound having an ethylene oxide unit,
The aqueous fluorescent ink for inkjet is characterized by containing.

In this ink, the resin emulsion is preferably an acrylic resin emulsion.

The water-soluble compound having an ethylene oxide unit is used in an amount of 1% by mass to 15% by mass based on the total mass of the ink.
It is also preferable that the content is not more than mass%.

It is also preferred that the water-soluble compound having an ethylene oxide unit is polyethylene glycol.

It is also preferable that the polyethylene glycol has at least 25 ethylene oxide units.

It is preferable that the polyethylene glycol is contained in an amount of 1 to 10% by mass based on the total mass of the ink.

It is also preferred that the water-soluble compound having an ethylene oxide unit is a nonionic surfactant.

It is also preferable that the nonionic surfactant has 25 or more ethylene oxide units.

It is preferable that the nonionic surfactant is contained in an amount of 1 to 5% by mass based on the total mass of the ink.

It is also preferred that the compound having an ethylene oxide unit is polyethylene glycol and a nonionic surfactant.

The present invention includes a recording unit including an ink containing section containing the above-mentioned aqueous fluorescent ink, and an ink jet head for discharging the ink.

The present invention also includes an ink cartridge containing the aqueous fluorescent ink described above.

The present invention further includes an ink jet recording apparatus characterized by comprising an ink container for storing the above ink, and an ink jet head for discharging the ink.

In this ink jet recording apparatus, it is preferable that the ink jet head is a bubble jet head.

The present invention also includes an ink jet recording method including a step of discharging the above-mentioned aqueous fluorescent ink by an ink jet method.

[0024]

Next, the present invention will be described in more detail with reference to preferred embodiments.

[Colored Resin Emulsion] The resin emulsion colored with a fluorescent dye used in the present invention is a component as a coloring material in the ink according to the present invention.
For example, an emulsion of an acrylic resin-based polymer compound dyed with a fluorescent dye (hereinafter referred to as “acrylic resin-based polymer emulsion”) can be used.

As the fluorescent dye, any dye having a fluorescent property can be used.
I. Acid Blue 9, C.I. I. Acid Yellow 7,
C. I. Acid Yellow 23, C.I. I. Acid Red 52, C.I. I. Acid Red 87, C.I. I. Acid Red 92, C.I. I. Acid dyes such as Acid Black 2; I. Basic Red 1, C.I. I. Basic Yellow 9, C.I. I. Basic Yellow 44, C.I.
I. Basic Violet 1, C.I. I. Basic Violet 7, C.I. I. Basic violet 10,
C. I. Basic Violet 11, C.I. I. Examples include basic dyes such as Basic Blue 45, but are not limited thereto.

The monomers constituting the acrylic resin-based polymer emulsion include acrylic acid and methacrylic acid, as well as styrene, vinyl chloride, esters of acrylic acid and methacrylic acid, maleic acid, fumaric acid and its esters, and acrylonitrile. Vinyl monomers and other urethane monomers can be used, but are not limited to these.

In the method for producing an acrylic resin-based polymer emulsion, one or two or more of the above monomers are polymerized or copolymerized in a solvent such as water. The method of polymerization or copolymerization is not particularly limited, but is preferably synthesized by emulsion polymerization.

The method of dyeing an acrylic resin-based polymer emulsion with a dye can be applied without any particular limitation as long as it can dye a polymer compound. The dye is added to the monomer before the synthesis of the polymer compound. It can be obtained by reacting, reacting a dye during polymerization, or reacting or dyeing after synthesis.

The content of the dye in the colored resin cannot be determined unequivocally because it varies depending on the kind of the dye and the like, but the content of the dye in the colored resin is 1% by mass to 10% by mass.
The following is preferred. If the amount is less than this, it may not be sufficient in terms of color development, and if the dye content is too large, the water resistance may be insufficient, or the concentration quenching of the fluorescence due to the high concentration of the dye may occur. .

[Water-soluble compound having an ethylene oxide unit which is solid at 25 ° C.] The ink of the present invention contains, as an essential component, an ethylene oxide unit (—CH ₂ CH ₂ O—) which is solid at 25 ° C. Containing water-soluble compounds.

This compound is a solid at 25 ° C. and is not particularly limited as long as it is a water-soluble compound having an ethylene oxide unit.
It is a polyethylene glycol or a nonionic surfactant which is solid at a temperature of ° C.

More specifically, a polyethylene glycol having at least 25 ethylene oxide units and a nonionic surfactant are preferred.

In polyethylene glycol, the number of ethylene oxide units is preferably 200 or less.

In the nonionic surfactant, the number of ethylene oxide units is preferably 60 or less.

The above nonionic surfactants include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene nonyl phenyl ether, Specific examples include those having an ethylene oxide chain of 25 or more, such as oxyethylene octyl phenyl ether, polyoxyethylene stearylamine, and polyoxyethylene, but of course, the present invention is not limited to these.

By the way, it is not clear why the water-soluble compound having an ethylene oxide unit which is solid at 25 ° C. stabilizes the fluorescence of the ink-jet recorded matter by the ink according to the present invention.
It is presumed that these compounds have the effect of suppressing concentration quenching (a phenomenon in which the fluorescence intensity is reduced by absorbing the emission of the fluorescent coloring material by another coloring material),
I'm not sure.

Furthermore, it is not clear why these compounds improve the ink ejection property in bubble jet recording, but it is speculated as follows.

In the ink containing the emulsion of the resin colored with the fluorescent dye, foaming for ink ejection is prevented by the hydrophobic portion of the emulsion,
It is considered that the fact that the bubble does not grow into a sufficiently large bubble causes unstable ejection. Hereinafter, in some cases, a resin emulsion, that is, an emulsion in which the resin is dispersed, is referred to as a “resin emulsion”, and a resin emulsion colored with a fluorescent dye is referred to as a “colored resin emulsion”.

On the other hand, polyethylene glycol having about 20 ethylene oxide units which is liquid at 25 ° C. can be freely mixed with water. In contrast, polyethylene glycol, which is solid at 25 ° C., has a finite solubility and is considered to have lost at least affinity for water more than liquid compounds. Therefore, these solid compounds are oriented to a colored resin emulsion having a more hydrophobic surface, and enhance the apparent hydrophilicity of the emulsion. Thus, it is considered that the suppression of foaming growth due to the colored resin emulsion is suppressed, and stable ink ejection is achieved.

The above description also applies to nonionic surfactants. In this case, since the surfactant having a hydrophobic unit is more effectively oriented to the fluorescent pigment emulsion, the number of units of ethylene oxide is smaller than that of polyethylene glycol, and the same effect can be achieved with a small amount.

In the case of a surfactant other than a solid having a small number of ethylene oxide units, the hydrophobicity of the compound becomes strong, so that the surfactant cannot be dissolved to a concentration at which a sufficient effect is exhibited, or the hydrophobicity of the colored resin emulsion is reduced. The effect is not obtained because the effect of relaxation is reduced.

[Ink] The aqueous fluorescent ink for inkjet according to the present invention comprises:
Manufactured as a solution in which a colored resin (a resin colored with a fluorescent dye) is dispersed as a so-called pigment in an aqueous liquid medium such as water by mixing with the compound having an ethylene oxide unit which is solid at 25 ° C. can do.

The content of these colored resin emulsions is determined by the dye concentration in the resin, but is preferably 1 to 40% by mass, more preferably 1 to 20% by mass in the ink.
Used in the range of mass%.

The compound having an ethylene oxide unit, which is solid at 25 ° C., accounts for 1% by mass in the ink.
To 15% by mass. When the content is 1% by mass or more, the effect of the present invention can be clearly exhibited, and
When the content is not more than mass%, an increase in the viscosity of the ink can be suppressed. If it exceeds 15% by mass, the effect of the present invention does not increase much.

In the ink, polyethylene glycol is added
It is preferable to contain 10% by mass or 1 to 5% by mass of a nonionic surfactant. This is because if the content exceeds 10 or 5% by mass, it is disadvantageous in that the effect is not so much improved, and the increase in the viscosity is slightly disadvantageous for nozzle clogging of the ink jet head.

It is also preferable to use these compounds in combination.

The aqueous liquid medium that can be suitably used for the ink according to the present invention is a mixed solvent of water and a water-soluble organic solvent.
Water is not general water containing various ions,
It is preferable to use ion-exchanged water (deionized water).

The water-soluble organic solvent used by mixing with water includes, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol and the like. Alkyl alcohols having 1 to 4 carbon atoms; amides such as dimethylformamide and dimethylacetamide; ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylenes such as polyethylene glycol and polypropylene glycol Glycols; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol,
1,2,6-hexanetriol, thiodiglycol,
Alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as hexylene glycol and diethylene glycol; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) Lower alkyl ethers of polyhydric alcohols such as ethers; N-methyl-2-pyrrolidone;
2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like. Among these many water-soluble organic solvents, polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether are preferable.

In general, the content of the water-soluble organic solvent in the ink is preferably in the range of 3 to 50% by mass, more preferably 3 to 30% by mass of the total mass of the ink.
Range.

[Recording Apparatus] Next, an example of the ink jet recording apparatus of the present invention suitable for performing recording using the above-described aqueous fluorescent ink of the present invention will be described below. A recording unit having an ink container containing ink or an ink cartridge having an ink container containing ink, and a recording unit having a head for ejecting the ink as ink droplets by the action of thermal energy. There is no particular limitation according to the present invention except for the aqueous fluorescent pigment ink of the present invention.

First, an example of a head configuration is shown in FIGS. FIG. 1 is a cross-sectional view of the head 13 along the ink flow path, and FIG. 2 is a cross-sectional view taken along line AB in FIG. The head 13 is obtained by bonding a glass, ceramic, silicon or plastic plate or the like having a flow path (nozzle) 14 through which ink passes to a heating element substrate 15. Heating element substrate 1
Reference numeral 5 denotes a protective layer 16 formed of silicon oxide, silicon nitride, silicon carbide or the like, electrodes 17-1 and 17-2 formed of aluminum, gold, an aluminum-copper alloy or the like, and H
Heating resistor layer 18 formed of a high melting point material such as fB2, TaN, TaAl, etc., heat storage layer 19 formed of thermally oxidized silicon, aluminum oxide or the like, formed of a material having good heat dissipation properties such as silicon, aluminum, aluminum nitride, etc. The substrate 20 is formed.

The electrodes 17-1 and 17- of the head 13
When a pulse-like electric signal is applied to the area 2, the area indicated by n on the heating element substrate 15 rapidly generates heat, bubbles are generated in the ink 21 in contact with the surface, and the meniscus 23 is protruded by the pressure. , Ink 21 is ejected through the nozzle 14 of the head, and ink droplets 24
And fly toward the recording material 25. In FIG.
FIG. 2 shows an external view of an example of a multi-head in which many heads shown in FIG. 1 are arranged. This multi-head has a multi-nozzle 26
And a heating element substrate 28 similar to that described with reference to FIG.

FIG. 4 shows an example of an ink jet recording apparatus incorporating this head. In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held and fixed by a blade holding member, and forms a cantilever. The blade 61 is arranged at a position adjacent to the recording area of the recording head 65, and in the case of this example,
The recording head 65 is held in a protruding form in the movement path.

Reference numeral 62 denotes a cap on the protruding opening surface of the recording head 65, which is disposed at a home position adjacent to the blade 61, moves in a direction perpendicular to the moving direction of the recording head 65, and comes into contact with the ink discharge port surface. And a configuration for performing capping. Further, reference numeral 63 denotes an ink absorber provided adjacent to the blade 61, which is held in a form protruding into the movement path of the recording head 65, similarly to the blade 61. The blade 61, the cap 62 and the ink absorber 63 constitute an ejection recovery section 64, and the blade 61
In addition, the ink absorber 63 removes moisture, dust, and the like from the ejection port surface.

Reference numeral 65 denotes a discharge energy generating means,
A recording head 66 for performing recording by discharging ink onto a recording material facing a discharge surface having discharge ports;
Is a carriage for moving the recording head 65 by mounting the same. The carriage 66 is slidably connected to a guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown).

As a result, the carriage 66 moves to the guide shaft 67.
And the recording head 65 can move the recording area and the area adjacent thereto.

Reference numeral 51 denotes a paper feeding unit for inserting a recording material;
52 is a paper feed roller driven by a motor (not shown). With such a configuration, the recording material is fed to a position facing the discharge port surface of the recording head 65, and is discharged to a discharge section provided with a discharge roller 53 as recording proceeds. In the above configuration, when the recording head 65 finishes recording and returns to the home position, the cap 62 of the ejection recovery unit 64 is retracted from the movement path of the recording head 65.
The blade 61 protrudes into the movement path. as a result,
The ejection port of the recording head 65 is wiped.

When capping is performed by contacting the cap 62 with the ejection surface of the recording head 65, the cap 62 moves so as to protrude into the moving path of the recording head. When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same positions as the positions at the time of the wiping described above. As a result,
Also in this movement, the ejection port surface of the recording head 65 is wiped. The above-described movement of the print head to the home position is performed not only at the time of printing end and at the time of ejection recovery, but also at a predetermined interval to the home position adjacent to the print area while the print head moves through the print area for printing. Then, the wiping is performed along with this movement.

FIG. 5 is a diagram showing an example of an ink cartridge containing ink supplied to the recording head shown in FIG. 4 via an ink supply member, for example, a tube (FIG. 4).
(Not shown). 45 is an ink cartridge. Here, 40 is an ink storage unit that stores the supply ink, for example,
The ink bag is provided with a rubber stopper 42 at the tip. By inserting a needle (not shown) into the stopper 42, the ink in the ink bag 40 can be supplied to the head. An ink absorber 44 receives the waste ink. The ink container preferably has a liquid contact surface with ink formed of polyolefin, particularly polyethylene.

The ink cartridge of the present invention is not particularly limited as long as it has an ink storing section for storing ink, except that the stored ink is the aqueous fluorescent pigment ink of the present invention.

In the present invention, a recording unit in which the head and the ink cartridge are separated from each other as shown in FIG. 6 is preferably used, as shown in FIG. In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink container containing ink, for example, an ink absorber is stored, and the ink in the ink absorber is transferred from a head unit 71 having a plurality of orifices. It is configured to be ejected as ink droplets. It is preferable for the present invention to use polyurethane as the material of the ink absorber. Further, a structure may be used in which the ink storage unit is an ink bag in which a spring or the like is provided inside without using an ink absorber. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere. This recording unit 70
Is used in place of the recording head 65 shown in FIG.

As long as the recording unit of the present invention is provided with an ink storage section for storing ink and a head section for discharging the ink as ink droplets by the action of thermal energy, the ink to be stored is not limited. There is no particular limitation except for the aqueous fluorescent pigment ink of the present invention.

[0064]

Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following description, “parts” and “%” are based on mass unless otherwise specified.

Example 1 1) Aqueous Fluorescent Colored Resin Emulsion Acrylic Resin Emulsion Colored with Fluorescent Acid Dye (trade name: SF-5017; manufactured by Shinloich Co.): 20 parts 2) Nonionic interface Activator polyoxyethylene cetyl ether (ethylene oxide 40 units), 25 ° C solid) (trade name: BC-40TX; manufactured by Nikko Chemicals Co., Ltd.): 2.0 parts 3) Other components ・ Ethylene oxide adduct of acetylene glycol ( Trade name: acetylenol EH: Kawaken Fine Chemical Co., Ltd.): 0.5 part ・ Diethylene glycol: 15 parts ・ Trimethylolpropane: 5 parts ・ Pure water: 57.5 parts After dissolution, a 2.5μm pore size microfilter (Fuji Film)
The mixture was filtered under pressure to prepare an ink.

Using the above ink, an ink jet recording apparatus BJC-430J (manufactured by Canon) having an on-demand type multi-bubble jet head for discharging ink by applying thermal energy according to a recording signal to the ink is used. Print evaluation was performed.

The paper used for the evaluation was Canon PPC paper and PB-paper.

As a result, a stable print was obtained. The printed matter had complete water resistance. When the printed matter was measured with a fluorometer, red fluorescence was observed, and no change in the fluorescence intensity due to the lot of paper was observed.

Example 2 1) Aqueous Fluorescent Colored Resin Emulsion Acrylic Resin Emulsion Colored with Fluorescent Acid Dye (Product Name: LUMIKOL NKW-3207C; Nippon Fluorescent): 15 parts 2) Polyethylene glycol Polyethylene glycol (molecular weight 4000, ethylene oxide average about 90 units, solid at 25 ° C): 7.0 parts 3) Other components ・ Diethylene glycol: 15 parts ・ Trimethylolpropane: 5 parts ・ Ethylene oxide adduct of acetylene glycol (product) Name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.): 0.5 part ・ Pure water: 57.5 parts Same as Example 1 except that the above components were used.
When the print was evaluated, good results were obtained. Further, in Example 2, red fluorescence was observed, and the fluorescence intensity was stable as in Example 1.

Example 3 1) Aqueous Fluorescent Colored Resin Emulsion Acrylic Resin Emulsion Colored with Fluorescent Acid Dye (trade name: SF-5014; manufactured by Schinloich): 30 parts 2) Polyethylene glycol and nonionic Surfactant • Polyethylene glycol (molecular weight 1000, average 25 units of ethylene oxide, 25 ° C. solid): 5. 0 parts ・ Polyoxyethylene oleyl ether (ethylene oxide 50 units) (trade name: B0-50; manufactured by Nikko Chemicals Co., Ltd.): 2.0 parts 3) Other components ・ Diethylene glycol: 15 parts ・ Trimethylolpropane: 5 parts ・Ethylene oxide adduct of acetylene glycol (trade name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.): 0.5 parts ・ Pure water: 42.5 parts Printed in the same manner as in Example 1 except that the above components were used. Upon evaluation, good results were obtained. Yellow-green fluorescence was observed, and the fluorescence intensity was stable as in Example 1. In Example 3, the combined use of polyethylene glycol and a surfactant enabled stable use even at a high emulsion concentration.

Comparative Example 1 1) Aqueous Fluorescent Resin Emulsion-Acrylic Resin Emulsion Colored with Fluorescent Acid Dye (trade name: SF-5017; manufactured by Shinloich Co.): 20 parts 2) Other components-diethylene glycol: 15 parts Trimethylolpropane: 5 parts Ethylene oxide adduct of acetylene glycol (trade name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.): 0.5 parts Pure water: 59.5 parts Printed in the same manner as in Example 1. As a result of evaluation, no ink was ejected from the print head, and no evaluation was possible.

Comparative Example 2 1) Aqueous Fluorescent Colored Resin Emulsion A resin emulsion colored with a fluorescent acidic dye (trade name: SF-5017; manufactured by Shinloich Co.): 20 parts 2) Nonionic surfactant poly Oxyethylene cetyl ether (ethylene oxide 10 units), 25 ° C liquid to paste form (trade name: BC-10TX; manufactured by Nikko Chemicals Co., Ltd.): 2.0 parts 3) Other components ・ Diethylene glycol: 15 parts ・ Trimethylol Propane: 5 parts ・ Ethylene oxide adduct of acetylene glycol (trade name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.): 0.5 parts ・ Pure water: 57.5 parts Print evaluation was performed in the same manner as in Example 1, and the print was faint. Printing was difficult and evaluation was difficult.

When the fluorescence intensity was measured by selecting a portion where the printing was good, it seemed that there was no problem with the printing density and the like visually, but the fluorescence intensity was varied and was not at a level usable for digital watermarking or the like.

Comparative Example 3 1) Aqueous Fluorescent Colored Resin Emulsion Acrylic Resin Emulsion Colored with Fluorescent Acid Dye (Product Name: SF-5014; manufactured by Schinloich): 20 parts 2) Polyethylene glycol Polyethylene glycol ( (Molecular weight: 200, liquid at 25 ° C.): 5.0 parts 3) Other components ・ Diethylene glycol: 15 parts ・ Trimethylolpropane: 5 parts ・ Ethylene oxide adduct of acetylene glycol (trade name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.) : 0.5 parts ・ Pure water: 54.5 parts When printing was evaluated in the same manner as in Example 1, no ink was ejected from the print head, and the evaluation was not possible.

[0075]

As described above, according to the present invention,
When used for bubble jet recording, it is possible to obtain a water-based fluorescent ink for inkjet which has excellent ink ejection properties and excellent image fastness. Further, the present invention provides an ink cartridge, a recording unit, and an ink jet recording apparatus and a method capable of stably obtaining high-quality image quality due to excellent ink ejection properties and obtaining a fluorescent image having excellent image fastness. Was done.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating an example of a head of an inkjet recording apparatus.

FIG. 2 is a cross-sectional view illustrating an example of a head of the inkjet recording apparatus.

FIG. 3 is an external perspective view of a head obtained by multiplying the head shown in FIG. 1;

FIG. 4 is a schematic perspective view illustrating an example of an ink jet recording apparatus.

FIG. 5 is a longitudinal sectional view illustrating an example of an ink cartridge.

FIG. 6 is a perspective view illustrating an example of a recording unit.

[Explanation of symbols]

 13: Head 14: Nozzle 15: Heating Element Substrate 16: Protective Layer 17-1, 17-2: Electrode 18: Heating Resistor Layer 19: Heat Storage Layer 20: Substrate 21: Ink 22: Discharge Orifice (Micro Hole) 23: Meniscus 24: ink droplet 25: recording material 26: multi-nozzle 27: glass plate 28: heating element substrate 40: ink bag 42: stopper 44: ink absorber 45: ink cartridge 51: paper feed unit 52: paper feed roller 53: paper discharge roller 61: blade 62: cap 63: ink absorber 64: ejection recovery unit 65: recording head 66: carriage 67: guide shaft 68: motor 69: belt 70: recording unit 71: head unit 72: atmosphere communication mouth

 ──────────────────────────────────────────────────の Continuation of the front page (72) Inventor Shinichi Hakamada 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hideki Takayama 3-30-2 Shimomaruko, Ota-ku, Tokyo F term in Canon Inc. (reference) 2C056 FA03 FC02 2H086 BA53 BA55 BA59 4J039 AD09 AE07 BE02 BE22 CA03 CA06 EA28 EA36 EA41 EA42 EA46 GA24

Claims (15)

[Claims] 1. A water-based fluorescent ink for inkjet, comprising: an emulsion of a resin colored with a fluorescent dye; and a water-soluble compound having an ethylene oxide unit, which is solid at 25 ° C. 2. The aqueous fluorescent ink according to claim 1, wherein the resin emulsion is an acrylic resin emulsion. 3. The method according to claim 1, wherein the water-soluble compound having an ethylene oxide unit is 1% by mass or more based on the total mass of the ink.
The aqueous fluorescent ink according to claim 1, wherein the aqueous fluorescent ink contains 5% by mass or less. 4. The aqueous fluorescent ink according to claim 1, wherein the water-soluble compound having an ethylene oxide unit is polyethylene glycol. 5. The aqueous fluorescent ink according to claim 4, wherein the polyethylene glycol has 25 or more ethylene oxide units. 6. The aqueous fluorescent ink according to claim 4, wherein the polyethylene glycol comprises 1 to 10% by mass of the total mass of the ink. 7. The water-soluble compound having an ethylene oxide unit is a nonionic surfactant.
The aqueous fluorescent ink according to any one of Items 1 to 3. 8. The aqueous fluorescent ink according to claim 7, wherein the nonionic surfactant has 25 or more ethylene oxide units. 9. The aqueous fluorescent ink according to claim 7, comprising 1 to 5% by mass of the nonionic surfactant based on the total mass of the ink. 10. The aqueous fluorescent ink according to claim 1, wherein the compound having an ethylene oxide unit is polyethylene glycol and a nonionic surfactant. 11. An ink storage section containing the aqueous fluorescent ink according to claim 1, and an ink jet head for discharging the ink. And a recording unit. 12. An ink cartridge containing the aqueous fluorescent ink according to claim 1. Description: 13. An ink storage section containing the ink according to claim 1, and an ink jet head for discharging the ink. Ink jet recording device. 14. The ink jet recording apparatus according to claim 13, wherein said ink jet head is a bubble jet head. 15. An ink jet recording method comprising a step of discharging the aqueous fluorescent ink according to claim 1 by an ink jet method.