JP3420275B2 - Recording liquid, inkjet recording method, ink cartridge, recording unit, and inkjet recording apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid (water-soluble pigment ink) used in an ink jet recording method in which energy (preferably heat energy) is applied to a recording liquid to eject droplets from fine pores for recording. Or dye ink), more specifically, copy paper, report paper, notebook, notepaper, bond paper, which are commonly used in offices and homes,
A recording liquid that can perform good inkjet recording on so-called plain paper such as uncoated paper such as continuous slip paper, and the like.
Inkjet recording method used, ink cartridge,
The present invention relates to a recording unit and an inkjet recording device .

[0002]

2. Description of the Related Art Conventionally, various compositions having various compositions have been proposed as a recording liquid used in an ink jet recording method.
Generally, a recording liquid composed of a pigment or a water-soluble dye, a water-soluble organic solvent, and water is used. The same applies to recording liquids for other writing instruments.

When this conventional recording liquid is recorded on plain paper on which no special ink receiving layer is formed, there is a common problem that bleeding occurs, although there are some differences depending on the composition. Therefore, a method has been proposed in which a high viscosity solvent is added to the recording liquid to suppress bleeding. However, a considerable amount of high-viscosity organic solvent is required to suppress bleeding. Therefore, there is a problem that the viscosity of the recording liquid becomes too high, the ink discharge speed at the nozzles decreases, and the surface tension decreases, resulting in unstable discharge. There is also a problem in that the degree of bleeding of printed images varies depending on the type of recording paper. For example, for the purpose of preventing bleeding, Japanese Patent Publication No. 60-500540, JP-A-63-15
Japanese Patent No. 9485 discloses a recording liquid for use in multi-starch-containing paper (bond paper or the like), which contains an iodide or the like that exhibits good color development in printing. However, this conventional technique cannot obtain a sufficient effect on a wide variety of plain paper.

Furthermore, since the water-soluble dye originally has poor light resistance, the light resistance of a recorded image often becomes a problem. In addition, since the ink is water-soluble, when the recorded image is exposed to rain, sweat, drinking water, etc., the recorded image may bleed or disappear, and the water resistance of the recorded image often becomes a problem. Therefore, a technique for practical use of an aqueous pigment ink for stationery has been proposed. For example, as a technique aiming at dispersion stability of an aqueous pigment ink, prevention of solidification of ink at a pen tip, and prevention of abrasion of balls of a ballpoint pen, JP-A-58-80368 and 61-200 are known.
No. 182, No. 61-247774, No. 61-2722.
No. 78, No. 62-568, No. 62-101671,
62-101672, JP-A-1-249869,
For example, there is Japanese Patent Laid-Open No. 1-301760. With these technologies, ballpoint pens and markers using water-based pigment inks have recently been marketed as products.

Further, as an ink jet recording ink using a water-based pigment ink, JP-A-56-147859 is known.
No. 56-147860, etc., a pigment ink using a specific water-soluble organic solvent and a polymer dispersant is proposed. Also, JP-A-4-57859 and JP-A-4-578.
In JP-A-60, an ink using a pigment and a dye together is proposed.

Generally, in the ink jet recording method,
It is extremely important for printing quality that the non-volatile components in the ejected ink rapidly aggregate on the recording paper. However, when inkjet recording is performed using the above-mentioned conventional water-based pigment ink, the non-volatile components aggregated on the recording paper are present as solids on the recording paper even after the ink is fixed, so that strong rubbing or fluorescence occurs. There was a problem that the printed surface was contaminated by tracing with a pen. Further, there is a problem that the print quality varies due to the difference in the recording paper.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. That is, an object of the present invention is to eliminate variations in printing quality due to differences in recording paper, to be excellent in fixing speed and quickness, and to obtain a stable recording image without a decrease in print density or bleeding , and a recording liquid for the same. Ink jet using
Printing method, ink cartridge, printing unit arrangement
Another object is to provide an inkjet recording device .

[0008]

The above-mentioned object of the present invention is a recording liquid used in an ink jet recording method for recording by ejecting the recording liquid as droplets from fine pores by applying energy to the recording liquid. Water-soluble resin (a) having at least an oxazoline group and a water-soluble resin having a carboxyl group , or CI Direct Yellow 4
1, CI Direct Black 51, CI Direct Black
Lou 149, CI Direct Black 174 and CI
Carboxy selected from the group consisting of Acid Green 34
It can be achieved by a recording liquid containing a dye (b) having a silyl group , and an inkjet recording method using the recording liquid. Further, the above-mentioned object of the present invention is an ink cartridge having an ink containing portion containing ink, wherein the ink is the recording liquid of the present invention; A recording unit comprising: an ink containing portion and a recording head for ejecting the ink contained in the ink containing portion by an inkjet method, wherein the ink is the recording liquid of the present invention. A recording unit characterized by; an ink cartridge having an ink containing portion containing ink, and a recording head for ejecting the ink contained in the ink containing portion by an inkjet method, wherein the ink is An ink jet recording apparatus, which is the recording liquid of the present invention; and an ink container. In an ink jet recording apparatus having a recording unit having a recording chamber and a recording head for ejecting the ink contained in the ink chamber by an inkjet method, the ink is the recording liquid of the present invention. This can be achieved by a characteristic inkjet recording device.

The recording liquid of the present invention may be an aqueous pigment ink or a dye ink.

When the water-based pigment ink is used, it contains a water-soluble resin (b) having a carboxyl group , and further contains a pigment (c), water (d), and a water-soluble organic solvent (e). Is desirable.

When using dye ink, CI dye
Toe Yellow 41, CI Direct Black 51, CI
Direct Blue 149, CI Direct Black 1
74 and CI Acid Green 34
It is desirable to contain the dye (b) having a carboxyl group to be extracted , and further contain water (d) and a water-soluble organic solvent (e).

[0012]

When the recording liquid of the present invention is used, the fixing speed and the refreshing property are excellent, and a stable recorded image can be obtained without lowering the printing density. This is particularly a compound having an oxazoline emissions groups are uniformly dissolved in an aqueous solution, when the water runs out is presumed to have the property of reacting with a carboxyl group.
That is, oxa <br/> sledding down groups contained in component (a) of the recording liquid of the present invention, a recording liquid was uniformly dissolved, and further, the recording liquid onto the recording paper from the ink jet recording head discharged, upon drying bound carboxyl groups with oxazoline <br/> Li down group with a compound having the component (a) (b) is,
It is presumed that a crosslinked structure is formed and a non-volatile component is formed into a film, which improves properties such as the refreshing property of the printed matter. Furthermore, since this cross-linking reaction occurs uniformly regardless of the type of paper, it is presumed that the dependence of printing quality on the type of recording paper can be eliminated.

The present invention will be described in detail below.

[0014] Component (a) used in the present invention are water-soluble resins having an oxazoline down <br/> group. For this component (a),
Examples thereof include oxazoline-based reactive polymers. This oxazoline-based reactive limer is available as a commercial product, for example, K-1000 series, K-1000 series manufactured by Nippon Shokubai Co., Ltd.
2000 series acrylic-styrene resin, RP
Examples thereof include styrene series resins such as S series and acrylonitrile-styrene series resins such as RAS series.

The water-soluble resin (a) is, for example, an oxazoline-based reactive polymer having one or more oxazolyl groups as represented by the following general formula (1).

[0016]

[Chemical 1]

[0017]

The content of this component (a) in the recording liquid is
0.1-10% by weight is desirable, 0.5-5% by weight
Is preferred. If this content is less than 0.1% by weight,
It tends to be insufficient to improve the quickness of printed matter.
On the other hand, when the content exceeds 10% by weight, there is a tendency that the clogging of the ejection port due to the increase in the viscosity of the ink is slightly generated.

Among the compounds (b) having a carboxyl group used in the present invention, the water-soluble resin (b-1) having a carboxyl group mainly used in the case of an aqueous pigment ink acts as a dispersant. As the water-soluble resin (b-1), any resin having a carboxyl group can be used. However, the weight average molecular weight is 1000 to 300.
The range of 00 is desirable, and the range of 3000 to 15000 is more preferable. Specifically, styrene, styrene derivatives, vinylnaphthalene, vinylnaphthalene derivatives, α,
β-ethylenically unsaturated carboxylic acid aliphatic alcohol ester, acrylic acid, acrylic acid derivative, maleic acid,
A block copolymer composed of two or more monomers (at least one of which is a hydrophilic monomer) selected from maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, fumaric acid derivatives, etc., random Examples thereof include copolymers, graft copolymers, and salts thereof. These resins are alkali-soluble type resins that are soluble in an aqueous solution in which a base is dissolved. The content of the water-soluble resin (b-1) in the recording liquid is preferably 0.1 to 5% by weight.

Among the compounds (b) having a carboxyl group used in the present invention, as the dye (b-2) having a carboxyl group mainly used in the case of dye ink, CI dye
Rect Yellow 41, CI Direct Black 51,
CI Direct Blue 149, CI Direct Black
174 and CI Acid Green 34
Dyes having a carboxyl group selected from among others are included .

The content of this dye (b-2) in the recording liquid is
It is determined depending on the properties required of the ink, etc., but generally about 0.2 to 20% by weight is desirable, 0.5 to 1
0 wt% is preferable, and 1-5 wt% is more preferable.

The pigment (c) used when the recording liquid of the present invention is used as an aqueous pigment ink may be any pigment as long as it has characteristics suitable for ink jet recording applications.
Examples of the pigment used in the black ink include carbon black, which is manufactured by a furnace method or a channel method, and has a primary particle diameter of 15 to 40 mμ and a specific surface area by the BET method of 50 to 300 square m / g. DBP oil absorption is 40-150ml / 100g, volatile content is 0.5-10
%, PH value 2-9 is desirable. For example, NO.230
0, NO.900, MCF88, NO.33, NO.40, NO.45, NO.52, MA7,
MA8, NO.2200B (above product name, made by Mitsubishi Kasei), RAVEN1
255 (trade name, made by Colombia), REGAL400R, REG
AL330R, REGAL660R, MOGUL L (trade name, manufactured by Cabot), Color Black FW1, Color Black FW18, Color B
lack S170, Color Black S150, Printex 35, Printex U
Commercial products such as (the above product name, manufactured by Degussa) can be used. Further, as the pigment used for the yellow ink, CI Pigment Yellow1, CI Pigment Yellow 2,
CI Pigment Yellow 3, CI Pigment Yellow 13, C.
I. Pigment Yellow 16, CI Pigment Yellow 83 and the like. As the pigment used for magenta ink,
CI Pigment Red 5, CI Pigment Red 7, CI Pigme
nt Red 12, CI Pigment Red 48 (Ca), CI Pigment R
ed 48, (Mn), CI Pigment Red 57 (Ca), CI Pigment
Red 112, CI Pigment Red 122 and the like can be mentioned. CI Pigment Blue is a pigment used for cyan ink.
1, CIPigment Blue 2, CI Pigment Blue 3, CI P
igment Blue 1:15, CI Pigment Blue 16, CI Pigme
nt Blue 22, CI Vat Blue 4, CI Vat Blue 6, etc. can be used. However, the pigment (c) is not limited to these.

The content of the pigment (c) in the recording liquid is 1 to 2
0% by weight is desirable, and further 2 to 12% by weight is preferable.

The recording liquid of the present invention contains the components described in detail above.
It is desirable that the recording liquid comprises (a), (b), (c) and the like dispersed or dissolved in, for example, a mixed solvent of water (d) and a water-soluble organic solvent (e).

The water (d) in this mixed solvent is preferably not ion-exchanged water (deionized water) but general water containing various ions. Examples of the water-soluble organic solvent (e) include methyl alcohol, ethyl alcohol, n
-Propyl alcohol, isopropyl alcohol, n-
Butyl alcohol, sec-butyl alcohol, ter
alkyl alcohols having 1 to 4 carbon atoms such as t-butyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or keto alcohols such as acetone and diacetone alcohol; tetrahydrofuran,
Ethers such as dioxane; polyethylene glycol,
Polyalkylene glycols such as polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6
-Hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol and other alkylene groups having an alkylene group containing 2 to 6 carbon atoms; glycerin; ethylene glycol monomethyl (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 can be mentioned. Among these water-soluble organic solvents, lower alkyl ethers of polyhydric alcohols such as diethylene glycol are preferable.

The content of water (d) in the recording liquid is 10 to 9
0 wt% is desirable, and 30 to 80 wt% is more desirable. The content of the water-soluble organic solvent (e) in the recording liquid is 3 to
It is preferably 50% by weight, more preferably 3-40% by weight.

In the recording liquid of the present invention, it is preferable that the entire recording liquid is prepared to be neutral or alkaline, for example, the recording liquid is excellent in solubility of the water-soluble resin (c) and excellent in long-term storage stability. It is desirable because it can be done. However, in this case, since it may cause corrosion of various members used in the inkjet recording apparatus, it is desirable to set the pH range to 7 to 10. Examples of the pH adjuster include various organic amines such as monoethanolamine, diethanolamine and triethanolamine, inorganic bases such as potassium hydroxide, sodium hydroxide, lithium hydroxide and potassium hydroxide, other organic mineral acids and minerals. Acid etc. are mentioned.

The recording liquid of the present invention further comprises the above-mentioned components (a) to
In addition to (e), various optional components may be added if necessary. For example, a surfactant, an antifoaming agent, an anticorrosive agent, a dispersant, a viscosity adjusting agent, a surface tension adjusting agent, a fluorescent whitening agent, a water-soluble dye (including a dye having no carboxyl group), etc. can be added. . Examples of the viscosity modifier include polyvinyl alcohol, celluloses, water-soluble resins and the like. Examples of the surfactant include various kinds of cation, anion or nonionic surfactants. Examples of the surface tension adjusting agent include diethanolamine and triethanolamine. In addition, a pH adjusting agent using a buffering agent, an antifungal agent and the like can be used. Further, in order to prepare the ink used in the ink jet recording method of charging the ink, an inorganic salt resistivity adjusting agent such as lithium chloride, ammonium chloride or sodium chloride may be added.

Furthermore, from the viewpoint of solving the problems of ink bleeding and drying and penetrability of recorded matter when recorded on plain paper, etc., and at the same time making good matching with the ink jet recording head, the physical property of the ink itself is 25. ℃
It is desirable that the surface tension is adjusted to 30 to 68 dyne / cm and the viscosity is adjusted to 15 cP or less, more preferably 5 cP or less.

As a method for producing the recording liquid of the present invention, for example, in the case of dye ink, a method of sufficiently mixing the respective components, then adjusting the pH as necessary, and performing pressure filtration and the like can be mentioned. .

In the case of an aqueous pigment ink, for example, the pigment (c) is added to an aqueous solution containing at least the water-soluble resin (b-1) and water (d), and the mixture is agitated and dispersed by the below-mentioned dispersing means. There may be mentioned a method in which a desired pigment dispersion liquid is prepared by carrying out a dispersion treatment and, if necessary, a centrifugal separation treatment, and the above components and the like are added to the dispersion liquid and stirred. Further, it is effective to carry out premixing for 30 minutes or more before the dispersion treatment of the aqueous solution containing the pigment (c). This premixing operation improves the wettability of the pigment surface and promotes adsorption on the pigment surface. As the disperser used for this dispersion, any of the commonly used dispersers can be used.
Examples thereof include a ball mill and a sand mill. Among these, a high speed type sand mill is preferable, and examples thereof include a super mill, a sand grinder, a bead mill, an agitator mill, a grain mill, a dyno mill, a pearl mill, and a cobol mill (all are trade names).

Further, as a method for obtaining the pigment (c) having a desired particle size distribution, the size of the pulverized media of the disperser is reduced, the filling rate of the pulverized media is increased, and the treatment time is increased. Examples of the method include a method of slowing down, a method of classifying with a filter or a centrifuge after crushing, or a combination of these methods.

When ink jet recording is carried out using the recording liquid of the present invention, the recording apparatus used is to apply heat energy corresponding to a recording signal to the ink in the recording head,
A device that generates droplets by the energy is suitable.

1 and 2 are views exemplifying the structure of a recording head which is a main part of such an ink jet recording apparatus. FIG. 1A shows the head 13 along the ink flow path.
1 (b) is a partial cross-sectional view of FIG.
It is a fragmentary sectional view of a B line. The recording head 13 is a heating head 1 used for heat-sensitive recording, such as glass, ceramics, or a plastic plate having a groove 14 through which ink passes.
5 (thin film head is shown in the figure, but is not limited to this).

The heating head 15 includes a protective film 16 made of silicon oxide and aluminum electrodes 17-1, 17.
-2, a heat generating resistor layer 18 formed of nichrome or the like, a heat storage layer 19, and a substrate 20 having a good heat dissipation property such as alumina. The ink 21 reaches the ejection orifice (fine hole) 22, and the pressure P forms a meniscus 23. When an electric signal is applied to the electrodes 17-1 and 17-2, a region indicated by n of the heating head 15 rapidly generates heat, bubbles are generated in the ink 21 in contact therewith, and the meniscus 23 is generated by the pressure. The ink 21 is ejected,
The recording droplet 25 becomes a recording droplet 24 by the orifice 22.
Fly towards. FIG. 2 is a partial perspective view of a multi-head in which a large number of heads shown in FIGS. 1A and 1B are arranged. The multi-head includes a glass plate 27 having a multi-groove 26,
A heating head 28 similar to that described with reference to FIG.

FIG. 3 is a perspective view showing an example of an ink jet recording apparatus incorporating a recording head. In FIG. 3, reference numeral 61 denotes a blade as a wiping member, one end of which is held by a blade holding member to serve as a fixed end, which is in the form of a cantilever. The blade 61 is disposed at a position adjacent to the recording area of the recording head, and in the case of this example, is held in a protruding form in the movement path of the recording head. Reference numeral 62 denotes a cap, which is arranged at a home position adjacent to the blade 61, and has a configuration in which it moves in a direction perpendicular to the moving direction of the recording head and comes into contact with the ejection surface to perform capping. Further, 63 is an ink absorber provided adjacent to the blade 61, and similarly to the blade 61, is provided so as to project in the moving path of the recording head. The blade 61, the cap 62, and the absorber 63 constitute a discharge recovery unit 64, and the blade 61 and the absorber 6
3 removes water, dust and dust from the surface of the ink ejection port. Reference numeral 65 denotes a recording head which has an ejection energy generating means and ejects ink to a recording material facing the ejection port surface where the ejection ports are arranged to perform recording, and 66 denotes a recording head 65 mounted to move the recording material. It is a carriage. The carriage 66 slidably engages with the guide groove 67, and a part of the carriage 66 is connected (not shown) to a belt 69 driven by a motor 68. As a result, the carriage 66 can move along the guide groove 67, and the recording head 65 can move the recording area and its adjacent area.

Reference numeral 51 denotes a paper supply section for inserting a recording material,
A paper feed roller 52 is driven by a motor (not shown). With these configurations, the recording material is supplied to the position facing the ejection port surface of the recording head, and is discharged to the paper supply unit provided with the discharge rollers 53 as the recording progresses.

In the above structure, when the recording head 65 returns to the home position after the recording is completed, the head recovery unit 64
The carriage 62 is retracted from the movement path of the recording head 65, but the blade 61 is projected in the movement path. As a result, the ejection port surface of the recording head 65 is wiped. When the cap 62 comes into contact with the ejection surface of the recording head 65 to perform capping, the cap 62 moves so as to project 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 position as the above-mentioned position for wiping. As a result, the ejection surface of the recording head 65 is wiped even during this movement.

The above-described movement of the recording head to the home position is performed not only at the end of recording and at the time of ejection recovery, but also at the home adjacent to the recording area at a predetermined interval while the recording head moves in the recording area for recording. After moving to the position, the wiping is performed with this movement.

FIG. 4 is a cross-sectional view showing an example of the ink cartridge 45 in which the ink to be supplied to the recording head through the ink supply tube is stored, and 40 is a bag in which the supply ink is stored. , A rubber stopper 4 at its tip
Two are provided. By inserting a needle (not shown) into this 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 jet recording apparatus used in the present invention is not limited to the one in which the head and the ink cartridge are separated as described above, and an apparatus in which they are integrated as shown in FIG. 5 is also suitable. Used. In FIG. 5, an ink jet cartridge (recording unit) 70 contains an ink absorber impregnated with ink, and the ink in the ink absorber has a head portion 71 having a plurality of orifices. It is configured to be ejected as an ink droplet from. Reference numeral 72 is an atmosphere communication port for communicating the inside of the cartridge with the atmosphere. The inkjet cartridge 70 is used in place of the recording head 65 shown in FIG. 3, and is detachable from the carriage 66.

[0043]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the following description, “part” means “part by weight” unless otherwise specified.

First, Examples 1 to 1 relating to the aqueous pigment ink
3 and Comparative Examples 1 to 3 will be described below.

Example 1 (Preparation of Pigment Dispersion) Styrene-acrylic acid-ethyl acrylate copolymer 1.5 parts (oxidation 140, weight average molecular weight 5000) monoethanolamine 1 part ion-exchanged water 81.5 Parts Diethylene glycol 5 parts The above components were mixed and heated to 70 ° C. in a water bath to completely dissolve the resin component. To this solution, 10 parts of carbon black (trade name MCF88, manufactured by Mitsubishi Kasei Co.) and 1 part of isopropyl alcohol were added, and after premixing for 30 minutes, dispersion treatment was performed. In this dispersion treatment, a sand grinder (made by Igarashi Kikai Co., Ltd.) was used as a disperser, and a pulverized medium (zirconium beads 1 m) was used.
m diameter), crushing medium filling rate 50% by volume, crushing time 3
It was time. Centrifugation (12000 RPM, 2
(For 0 minutes) to remove coarse particles to obtain a dispersion liquid.

(Preparation of recording liquid) 30 parts of the pigment dispersion 10 parts of glycerin Ethylene glycol 5 parts N-methylpyrrolidone 5 parts 2 parts ethyl alcohol K-1010E (Nippon Shokubai Co., Ltd.) 2 parts Deionized water 46 parts A recording liquid was obtained by mixing the above components.

Example 2 (Preparation of Pigment Dispersion) Styrene-maleic acid-maleic acid half ester copolymer 4 parts (oxidization 70, weight average molecular weight 1200) aminomethyl propanol 2 parts ion-exchanged water 74 parts diethylene glycol 5 parts The above components were mixed and heated to 70 ° C. in a water bath to completely dissolve the resin component. To this solution was added 15 parts of carbon black (trade name MCF88, manufactured by Mitsubishi Kasei),
After premixing for 30 minutes, dispersion treatment was performed. In this dispersion treatment, a pearl mill (manufactured by Ashizawa Co., Ltd.) was used as a disperser, and the crushed medium (glass beads 1 mm diameter), the crushed medium filling rate was 50% by volume, and the discharge rate was 100 ml / min. Further centrifugation (120
(00 RPM, 20 minutes) to remove coarse particles to obtain a dispersion liquid.

(Preparation of Recording Liquid) Pigment Dispersion Liquid 30 parts Glycerin 8 parts Ethylene glycol 5 parts Ethanol 5 parts RPS-1001 (manufactured by Nippon Shokubai Co., Ltd.) 1 part Ion-exchanged water 51 parts A recording liquid was obtained by preparing 8 to 10 with aminomethyl propanol.

Example 3 (Preparation of Pigment Dispersion) α-Methylstyrene-methylacrylate-acrylic acid 2.0 parts (oxidation 95, weight average molecular weight 8000) ion-exchanged water 81.5 parts ethylene glycol 5 parts Mix the ingredients and heat to 70 ° C in a water bath,
The resin component was completely dissolved. To this solution, 11 parts of carbon black (trade name S170, manufactured by Degussa) and 1 part of isopropyl alcohol were added, and after premixing for 60 minutes, dispersion treatment was performed. In this distributed processing,
Using a sand grinder (Igarashi Kikai Co., Ltd.) as a disperser, crushed media (zirconium beads 0.5 mm)
Diameter), filling rate of grinding medium 70% by volume, grinding time 10
It was set to 0 hours. Further centrifugation (12000 RPM,
20 minutes) to remove coarse particles to obtain a dispersion liquid. (Preparation of Recording Liquid) Pigment Dispersion Liquid 30 parts Glycerin 12 parts Diethylene glycol 10 parts 2-Pyrrolidone 5 parts CX-K2010E (manufactured by Nippon Shokubai Co., Ltd.) 0.5 parts Ion-exchanged water 42.5 parts Mix the above components. To obtain a recording liquid.

<Comparative Examples 1 to 3> In Examples 1 to 3,
A recording liquid was obtained in the same manner as in Examples 1 to 3 except that the compound having an oxazolyl group was not added during the preparation of the recording liquid and the same amount of ion-exchanged water was added instead.

<Evaluation of Recording Liquids> Copy papers (manufactured by Canon Inc.) were recorded by an inkjet recording device having an on-demand type multi-recording head which ejects the recording liquids by applying thermal energy according to a recording signal using each recording liquid. , NP-DRY copy paper), and the following points were evaluated.

1. Print density of printed matter: The print density of the printed matter was measured by a Macbeth densitometer (TR918).

2. Fixing speed: Printing area (solid and characters)
Rubbing with a filter paper (product name No. 5C, manufactured by Toyo Sashigami Co., Ltd.),
The time (seconds) at which scraping occurs is measured, and this is defined as the fixing speed.

3. Quickness of printed matter: The printed matter was rubbed with a highlighter pen and evaluated for quickness in the following three stages. ○ -Printing is not blurred even after rubbing 5 times with a highlighter pen. △ -Printing is not blurred even after rubbing three times with a highlighter pen. × -Printing is blurred after rubbing once with a highlighter pen.

The results of these evaluations are summarized in Table 1.

[0056]

[Table 1] As is clear from the results shown in Table 1, since the recording liquids of Examples 1 to 3 contained the compound having an oxazolyl group, the printing density, the fixing speed, and the refreshing property were higher than those of the recording liquids of Comparative Examples 1 to 3. Was excellent.

Next, Examples 4 to 9 and Comparative Examples 4 to 9 relating to the dye ink will be described below.

<Examples 4 to 8 and Reference Example 1 > The following components were mixed and stirred for 5 hours, then the pH was adjusted to 7.5 with a 0.1% aqueous solution of sodium hydroxide, and the pore size was adjusted to 0. An ink of the present invention was obtained by pressure filtration with a membrane filter (trade name: Fluoro Filter, manufactured by Sumitomo Electric Industries, Ltd.) of 0.22 μm. (Example 4) C.I. I. Direct Yellow 41 2 parts Diethylene glycol 15 parts K-1010E (manufactured by Nippon Shokubai Co.) 3 parts Ion-exchanged water 80 parts (Example 5) C.I. I. Direct Black 51 3 parts Triethylene glycol 10 parts N-methyl-2-pyrrolidone 3 parts RPS-1001 (manufactured by Nippon Shokubai Co.) 1 part Ion-exchanged water 83 parts (Example 6) C.I. I. Direct Blue 149 2.5 parts 1,2,6-hexanetriol 5 parts diethylene glycol 10 parts CX-K2010E (manufactured by Nippon Shokubai Co., Ltd.) 3 parts ion-exchanged water 83 parts ( Reference Example 1 ) H112286 (manufactured by ICI) 2 parts thio Glycol 6 parts Diethylene glycol 9 parts K-1020E (manufactured by Nippon Shokubai Co., Ltd.) 3 parts Acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.5 parts Ion-exchanged water 79.5 parts (Example 7 ) C.I. I. Direct Black 174 3 parts Ethylene glycol 8 parts Diethylene glycol 7 parts RAS-1005 (manufactured by Nippon Shokubai Co., Ltd.) 1 part Ethylene glycol monobutyl ether 1 part Ion-exchanged water 80 parts (Example 8 ) C.I. I. Acid Green 34 3 parts Ethylene glycol 8 parts Triethylene glycol 7 parts K-1020E (manufactured by Nippon Shokubai Co.) 3 parts Triethylene glycol monobutyl ether 1 part Ion-exchanged water 78 parts.

<Comparative Examples 4 to 9> In Examples 4 to 6, Reference Example 1, and Examples 7 and 8 ,
Without addition of compounds during the recording liquid produced having oxazoline down group, the same amount of ion-exchanged water was added to the Instead, otherwise Example 4-6, Reference Example 1, and exactly the same manner as in Examples 7 and 8 To obtain a recording liquid.

<Evaluation of Recording Liquid> An ink jet printer (trade name BJ-10v, manufactured by Canon Inc.) using each recording liquid and using a heating element as an ink ejection energy source.
This printer was used to record on commercial copy paper and bond paper, and the following points were evaluated.

1. Fixability of printed matter: After printing 5 seconds, 10 seconds, 20 seconds, and 30 seconds after printing on commercially available copy paper and bond paper, the printed portion is made with a filter paper (product name No. 5C, manufactured by Toyo Soshi Paper Co., Ltd.). Rubbing, and evaluated as follows (25 ° C., 6
Evaluation under 0% RH environmental conditions).

◎ -No blurring in 5 seconds ○ -No blur in 10 seconds △ -No scratches in 20 seconds × − There is a blur in 30 seconds.

2. Bleeding occurrence rate: After printing 300 dots discontinuously on commercially available copy paper and bond paper, leave it for 1 hour or more, and then count the number of dots that bleed with a microscope, and calculate the ratio to the total number of dots. It was expressed in% and evaluated as follows (printed under environmental conditions of 25 ° C. and 60% RH).

○ -10% or less △ − 11 to 30% × -31% or more.

3. Clogging property: To evaluate the clogging property at the time of reprinting after a temporary stop of printing, after filling the printer with a predetermined ink and printing alphanumeric characters continuously for 10 minutes, the printing is stopped, After leaving for 10 minutes without a cap, etc., it was evaluated by the presence or absence of defective parts such as scratches and chips of letters when printing alphanumeric characters again (evaluation under environmental conditions of 25 ° C. and 60% RH). .

○ − No defective portion from the first letter △ -Part of the character is scratched or missing × − Characters cannot be printed at all.

4. Frequency response: The obtained printed matter was visually evaluated for the printed state, that is, the defective state such as blurring or white spots, and the defective state at the landing points such as splash and twist.

⊚-Following condition of ink with frequency is good, solid print and character printing are free from scratches, white spots, and defective landing points. ○ -Following condition of ink with frequency is almost good, and in character printing Scratches, white spots, and defective spots are not seen, but slight scratches are seen in solid printing. In the case of smearing and white spots, about 1/3 of the whole solid printing is observed. X − In the solid printing, there are many streaking and white spots, and also in character printing, there are scratches and defective landing points.

[0069]

[Table 2] As is clear from the results shown in Table 2, Examples 4 to 6 and Reference
Example 1, since the recording liquid according to Example 7 and 8 containing a compound having an oxazoline down group, as compared with the recording liquid of the comparative example 4-9, the fixing property, bleeding incidence, clogging resistance, with respect to frequency response Overall it was excellent.

[0070]

As described above, when ink jet recording is carried out using the recording liquid of the present invention, there are no variations in printing quality due to differences in recording paper, excellent fixing speed and quickness, and reduction in printing density. A recorded image without bleeding can be obtained. Further, since it is not necessary to add a high-viscosity organic solvent as in the prior art, stable recording is possible without problems such as ink ejection stability and solidification at the head tip.

Therefore, according to the recording liquid of the present invention, it is possible to perform high quality recording on plain paper such as commonly used copy paper, report paper, notebook, notepaper, bond paper and continuous slip paper. .

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of a recording head that is a main part of an inkjet recording apparatus, in which (a) is a partial cross-sectional view of the head along an ink flow path, and (b) is A in (a).
FIG. 6 is a partial cross-sectional view taken along the line B.

FIG. 2 is a partial perspective view of a multi-head in which a large number of heads shown in FIG. 1 are arranged.

FIG. 3 is a perspective view showing an example of an ink jet recording apparatus incorporating a recording head.

FIG. 4 is a cross-sectional view showing an example of an ink cartridge that contains ink to be supplied to a recording head via an ink supply tube.

FIG. 5 is a perspective view showing a recording unit in which a recording head and an ink cartridge are integrated.

[Explanation of symbols]

13 heads 14 groove 15 heating head 16 Protective film 17-1, 17-2 Aluminum electrode 18 Heating resistor 19 Heat storage layer 20 substrates 21 ink 22 Discharge orifice (fine hole) 23 Meniscus 24 recording droplets 25 Recorded material 26 multi groove 27 glass plate 28 heating head 40 Ink bag containing ink for supply 42 rubber stopper 44 ink absorber 45 ink cartridge 51 Paper supply section for inserting recording material 52 Paper feed roller 53 Paper ejection roller 61 Wiping member (blade) 62 cap 63 ink absorber 64 Discharge recovery unit 65 recording head 66 carriage 67 Guide groove 68 motor 69 belt 70 Inkjet cartridge (recording unit) 71 Head 72 Air communication port

Front Page Continuation (72) Inventor Akio Kashiwazaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-4-211467 (JP, A) JP-A-2-115238 ( JP, A) JP 2-99537 (JP, A) JP 2-1772 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 11 / 00-11 / 20 B41J 2/01-2/21 B41M 5/00

Claims (11)

(57) [Claims] 1. A recording liquid used in an inkjet recording method for recording by discharging the recording liquid as droplets from fine pores by applying energy to the recording liquid, the water-soluble resin having at least an oxazoline group ( a)
And a water-soluble resin having a carboxyl group , or CI
Direct Yellow 41, CI Direct Black 5
1, CI Direct Blue 149, CI Direct Blue
Consists of rack 174 and CI Acid Green 34
A recording liquid containing a dye (b) having a carboxyl group selected from the group . 2. A water-soluble resin having a carboxyl group
The recording liquid according to claim 1 , which further comprises (b) and further contains a pigment (c), water (d), and a water-soluble organic solvent (e). 3. CI Direct Yellow 41, CI Da
Elect Black 51, CI Direct Blue 14
9, CI Direct Black 174 and CI Acid
The recording liquid according to claim 1 , which contains a dye (b) having a carboxyl group selected from the group consisting of green 34 , and further contains water (d) and a water-soluble organic solvent (e). 4. The surface tension at 25 ° C. is 30 to 68.
The recording liquid according to claim 1, wherein the recording liquid is dyne / cm. 5. The viscosity according to claim 1, which has a viscosity of 15 cP or less.
The recording liquid according to any one of 1. 6. The recording liquid according to claim 5, which has a viscosity of 5 cP or less. 7. The ink jet recording method and performing recording by out micropores or al ejection by imparting energy to a recording liquid according to any one of claims 1 to 6. 8. An ink cartridge provided with an ink containing portion containing ink, wherein the ink is the recording liquid according to any one of claims 1 to 6. 9. A recording unit comprising an ink containing portion containing ink and a recording head for ejecting the ink contained in the ink containing portion by an ink jet method, wherein the ink comprises: Item 7. A recording unit comprising the recording liquid according to any one of items 1 to 6. 10. An ink jet recording apparatus comprising an ink cartridge having an ink containing portion containing ink, and a recording head for ejecting the ink contained in the ink containing portion by an ink jet method.
An ink jet recording apparatus, wherein the ink is the recording liquid according to any one of claims 1 to 6. 11. An ink jet recording apparatus comprising a recording unit having an ink containing portion containing ink and a recording head for ejecting the ink contained in the ink containing portion by an ink jet method. Item 7. An ink jet recording apparatus, which is the recording liquid according to any one of Items 1 to 6.