JP3133428B2 - Ink jet recording liquid, method for producing the same, and ink jet recording method using the same - 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 suitable for an ink jet printer, and to a recording method in which recording liquid is caused to fly from the orifice of a recording head by the action of thermal energy to perform recording on so-called plain paper.

[0002]

2. Description of the Related Art The ink jet recording method has the advantages of generating less noise during recording and obtaining a high-resolution recorded image at a high speed by using a highly integrated head. In such an ink jet recording system, an ink obtained by dissolving various water-soluble dyes in water or a mixture of water and an organic solvent is used. However, when water-soluble dyes are used, these water-soluble dyes are inherently inferior in light resistance, so that the light resistance of recorded images often becomes a problem.

[0003] Further, since the ink is water-soluble, water resistance of a recorded image often poses a problem. That is, rain, sweat, or water of food and drink splashes on the recorded image,
The recorded image may bleed or disappear. In particular, for a magenta dye, it is difficult to achieve both the color tone, light fastness, and water fastness, and various attempts have been made, but a dye having sufficient performance has not yet been obtained.

On the other hand, there is a similar problem in stationery using a dye with a ballpoint pen or the like, and various aqueous pigment inks for stationery have been proposed in order to solve the problems of light resistance and water resistance. Japanese Patent Application Laid-Open No. 58-803 discloses an example of studying dispersion stability, prevention of ink solidification at a pen tip, and prevention of abrasion of a ballpoint pen for practical use of an aqueous pigment ink.
No. 68, JP-A-61-200182, JP-A-61-247774, and JP-A-61-272278.
JP, JP-A-62-568, JP-A-62-10
1671 JP, Sho 62- 101672, JP-A No. 1-249869, JP-A No. 1 -301760
And the like. Recently, ballpoint pens and markers using water-based pigment inks are on the market as products,
Further, as the aqueous pigment ink using a red pigment, JP 54-10023, JP-Sho 61-155280
JP, Sho 61-200182, JP-Sho 61
-247774, JP Sho 62-568, JP Patent Laid-Open No. 1-117975 Publication, and the like.

On the other hand, an ink jet recording liquid is required to have a performance different from that of an aqueous pigment ink for stationery, and the amounts of impurities are specified in JP-A-1-204979 and JP-A-1-204980. There is a technology for improving the reliability by applying a dispersion system called a pigment ink to ink jet recording.Prevention of ink solidification at the head end by leaving for a long time is an important technical issue, and In designing a pigment ink, the composition of the ink is an important point. JP-A-1-228
Japanese Patent No. 2273 discusses prevention of solidification at the head end. However, even with these known techniques, an ink having excellent ejection stability using a pigment of stable color has not been obtained.

[0006]

When the conventional aqueous pigment ink for stationery is used as it is in the ink jet recording system by causing the recording liquid to fly by the action of thermal energy from the orifice of the recording head as it is, there is a significant obstacle to the ejection stability. Wake up.

Further, some conventional water-based pigment inks include:
Although excellent in dischargeability in a relatively short time, there is a problem that if the drive conditions of the recording head are changed or continuous discharge is performed for a long time, discharge becomes unstable, and finally discharge stops.

Accordingly, an object of the present invention is to provide an aqueous pigment ink having a long-term stability and a good magenta color.

Further, an object of the present invention is to solve the above-mentioned problems of the technology, to achieve stable ejection even when the driving conditions are changed or used for a long time, and to provide excellent long-term storage stability. An object of the present invention is to provide an ink jet magenta recording liquid in which solidification of ink at the head end is eliminated.

It is a further object of the present invention to provide an ink jet recording method which enables stable high-speed recording at all times and prints on uncoated paper to provide a recorded image having excellent fastness such as water resistance and light resistance. It is in.

[0011]

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

That is, the present invention is represented by the following general formula:
And a water-soluble resin.
Aqueous media (preferably polyhydric alcohols and / or
(Including alkyl ethers and aliphatic monohydric alcohols)
An ink jet recording liquid comprising the pigment and the water.
The ratio with the soluble resin ranges from 15: 1 to 30: 1 by weight.
Ink-jet recording liquid characterized in that
Things.

[0013]

Embedded image (In the formula, R represents H, CH ₃ or Cl) Further, the i
A method for producing an ink jet recording liquid, comprising:
Aqueous resin at a weight ratio of 15: 1 to 30: 1
A pigment dispersion is prepared by dispersing in the presence of a medium,
It is characterized by having a step of further adding an aqueous medium to the dispersion.
Related to a method for producing an ink jet recording liquid
It is. Further, heat energy is applied to the recording liquid described above.
And discharge it as ink droplets from the orifice to record
Ink jet recording by attaching to a material
This is related to the method of recording the data. Hereinafter, the present invention will be described in detail.

The recording liquid of the present invention has various properties particularly suitable for an ink jet printer using thermal energy.

The present inventors have prepared red pigments having various chemical structures with compositions conventionally proposed for stationery and the like in order to apply them to ink jet printers using an aqueous pigment ink having a magenta color. Was applied to a recording paper and evaluated for fastness and color tone. As a result, it was found that the pigment of the above general formula exhibited extremely good color tone and fastness. Then, when these inks were used in an ink jet recording apparatus utilizing thermal energy, there was still a problem in that the ejection still caused a remarkable trouble and a good printed matter could not be obtained. Therefore, the present inventors have further investigated the cause and found several factors. One is that when a pulse is applied to such a conventional stationery ink, a deposit is formed on the thin-film heating resistor due to the action of the heat, and the ink foaming becomes incomplete, causing ejection disturbance and non-ejection. That is. Further, even when no deposit is generated on the thin film resistor, there is a case where non-discharge occurs because the foaming is incomplete and the discharge of the droplet does not respond to the applied pulse. That is, in order to discharge the ink stably from the nozzle tip, it is necessary that the ink foams to a desired volume on the thin film resistor, and that the foaming and defoaming be repeated in a desired time. However, conventional stationery inks do not take into account their performance at all, so if the ink jet recording apparatus is filled as it is and recorded, the various inconveniences described above occur.

The inventors of the present invention have conducted intensive studies on the formulation of an ink which is thermally stable and capable of optimal foaming with an aqueous pigment ink. As a result, the pigment contained in the recording liquid and represented by the above general formula is obtained. The ratio of the water-soluble resin is in the range of 15: 1 to 30: 1 by weight, and a polyhydric alcohol and an aliphatic monohydric alcohol are used in combination as the water-soluble organic solvent. By containing 10% or more of the total weight, it is possible to always stably eject ink without generating deposits on the thin-film heating resistor, and the present invention has been completed.

The recording liquid for ink jet recording of the present invention is intended to maintain a long-term stability by combining a water-soluble resin with a pigment. If the ratio of the water-soluble resin to the pigment is less than 30: 1, the recording liquid becomes stable. No ink was obtained,
On the other hand, when the ratio is larger than 15: 1, the above-described inconvenience occurs. It is considered that the water-soluble resin contributes to stability by being adsorbed on the pigment.

As the pigment to be used in the present invention, any quinacridone pigment represented by the above-mentioned general formula can be used, in particular, a magenta-based color.
2,209, CI PIGMENT VIOLET 19, etc., specifically, HOSTAPERM REDEG TRANS., HOSTAPERM RED VIOLET
ER-02, HOSTAPERM RED E5B02, HOSTAPERM PINK E (Hoec
hst), Fastogen Super Magenta RT, Fastogen Super
Red 7083Y (Dainippon Ink), Fuji Fast Red 9900RM
(Manufactured by Fuji Dye) and the like. The amount of the pigment used in the present invention is preferably used in a range of 3 to 30% by weight in the recording liquid.

Since there is a concern that the ink may solidify at the tip of the head, it is necessary to improve the airtightness of the cap, periodically clean the face of the head with a wiper or the like, or provide a cleaning means with alkali in the apparatus. It is known to take. These measures are not always preferred solutions in terms of cost and safety. For this reason, the present inventors have studied means for preventing the solidification of the ink at the head end by improving the components of the ink, and by using a water-soluble resin in combination with the pigment as described above, It has been found that by containing at least 10% (parts by weight) or more of a polyhydric alcohol, solidification of the ink at the tip of the head is remarkably improved.

The water-soluble resin used as a pigment dispersant in the recording liquid of the present invention is soluble in an aqueous solution in which an amine or a base is dissolved, and usually has a weight average molecular weight in the range of 3,000 to 30,000. Furthermore, preferably 5000 to 15
000. Those satisfying this condition easily and preferably usable in the present invention include styrene-acrylic acid copolymer, styrene-acrylic acid-alkyl acrylate copolymer, styrene-maleic acid copolymer, styrene-maleic acid -Alkyl acrylate copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl Naphthalene-maleic acid copolymer, styrene-maleic anhydride-
Maleic acid half ester copolymers, or salts thereof, and the like. These water-soluble resins are preferably contained in the range of 0.05 to 1% by weight based on the total amount of the recording liquid.

Examples of the pH adjuster that can be used in the recording liquid of the present invention include various organic amines such as monoethanolamine, diethanolamine and triethanolamine, sodium hydroxide, lithium hydroxide, potassium hydroxide and the like. And inorganic acids such as alkali metal hydroxides, organic acids and mineral acids.

These pigments and water-soluble resins are dispersed or dissolved in an aqueous medium.

An aqueous medium suitable for the recording liquid of the present invention is a mixed solvent of water and a water-soluble organic solvent. Water is not general water containing various ions, but is ion-exchanged water (deionized water). It is preferred to use

Other optional solvent components which can be used in combination with the recording liquid of the present invention include water-soluble organic solvents such as methyl alcohol, n-propyl alcohol, and n-propyl alcohol.
-Butyl alcohol, sec-butyl alcohol, te
alkyl alcohols having 1 to 4 carbon atoms such as rt-butyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethylene glycol; Polyalkylene glycols such as polypropylene glycol; alkylene glycols having an alkylene group containing 2 to 6 carbon atoms such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, thiodiglycol, hexylene glycol, diethylene glycol; ethylene Glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or Lower alkyl ethers of polyhydric alcohols ethyl) ether; N- methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone. 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. Among polyhydric alcohols, triol is a highly hygroscopic solvent,
Particularly preferred. Examples of the triol used in the present invention include glycerin, 1,2,6-hexanetriol, petriol (trade name), and trimethylolpropane. These derivatives can be used as long as they have good hygroscopicity.

It has been found that it is effective to add ethanol or isopropyl alcohol in an amount of 3% or more to obtain the stability of the ejection of the recording liquid. This is presumably because the addition of these enables more stable foaming of the recording liquid on the thin film resistor. However, if these are added excessively, there is a disadvantage that the print quality of the printed matter is impaired. Therefore, it has been found that the appropriate concentration thereof is 3 to 10%. Further, as these effects, by adding these to the dispersion liquid, generation of bubbles during dispersion can be suppressed, and efficient dispersion can be performed.

The total content of the water-soluble organic solvent in the recording liquid of the present invention is generally in the range of 3 to 50% by weight, preferably in the range of 3 to 40% by weight based on the total weight of the recording liquid. The water used is 10-90% by weight of the total weight of the recording liquid,
Preferably it is in the range of 30 to 80% by weight.

The recording liquid of the present invention may contain a surfactant, an antifoaming agent, a preservative, etc., in addition to the above components, in order to give desired physical properties as required. Can be added as long as the object of the present invention is not impaired.

Surfactants can also be used in combination. These include anionic surfactants such as fatty acid salts, higher alcohol sulfates, liquid fatty oil sulfates, alkyl allyl sulfonates, and polyoxyethylene alkyl. There are nonionic surfactants such as ethers, polyoxyethylene alkyl esters, and polyoxyethylene sorbitan alkyl esters, and one or more of these can be appropriately selected and used. The amount used depends on the dispersant, but is preferably 0.01 to 5% by weight based on the total amount of the ink.

At this time, the surface tension of the recording liquid is 30 dyne / cm
It is preferable to determine the amount of the activator to be added as described above. This is because, if the surface tension of the recording liquid shows a smaller value, in a recording method such as the present invention, undesired situations such as printing distortion due to the wetting of the nozzle tip (deviation of the landing point of the ink droplet) are caused. Because.

Further, it is desirable that the pigment and the water-soluble resin are once prepared in a pigment dispersion of 10% or more, preferably 30% or less on a weight basis, and then formulated into a recording liquid.
The reason is that it is convenient to disperse the pigment efficiently and obtain an optimal dispersion state by making the pigment and the water-soluble resin at a certain concentration or more in the dispersion.

As a method of preparing the recording liquid of the present invention, first, a water-soluble resin is added to an aqueous solution containing an amine or a base, a pigment is further added, and the mixture is stirred and dispersed. To obtain the desired dispersion.
Next, the above-mentioned components are added to the dispersion and stirred to obtain a recording liquid.

The amount of the amine or base that dissolves the water-soluble resin is preferably at least the equivalent of the amount of amine or base determined by calculation from the acid value of the resin. The amount of this amine or base is determined by the following equation.

Amount of amine or base (g) = (acid value of resin * molecular weight of amine or base * resin amount (g)) /
56000 (Note: The molecular weight of KOH is 56.) It is also preferable to perform premixing for 30 minutes or more before dispersing the aqueous solution containing the pigment. This premixing operation improves the wettability of the pigment surface and promotes adsorption on the pigment surface.

As amines to be added to the dispersion, organic amines such as monoethanolamine, diethanolamine, triethanolamine and aminomethylpropanol, and ammonia are preferable. As the base to be added to the dispersion, an inorganic alkali agent such as a hydrate of an alkali metal salt such as sodium hydroxide, lithium hydroxide or potassium hydroxide is preferable.

On the other hand, the dispersing machine used in the practice of the present invention, if generally used as dispersing machine, may be any, but for example, a ball mill, a roll mill, and a sand mill or the like. Among them, a high-speed sand mill is preferable, and examples thereof include a super mill, a sand grinder, a bead mill, an agitator mill, a Glen mill, a Dyno mill, a pearl mill, and a Kobol mill (all trade names).

In the present invention, commercially available pigments are usually sufficient, but a method for obtaining a pigment having a desired particle size distribution is, for example, to reduce the size of the pulverizing media of the dispersing machine and to increase the filling rate of the pulverizing media. , The processing time is lengthened, the discharge speed is slowed, and after pulverization, classification is performed using a filter, a centrifuge, or the like. Alternatively, a combination of these techniques may be used.

The recording liquid of the present invention is particularly preferably used in an ink jet recording system in which recording is performed by discharging droplets by the action of thermal energy, but it goes without saying that it can also be used for general writing instruments.

As a recording apparatus suitable for performing recording using the recording liquid of the present invention, a thermal energy corresponding to a recording signal is applied to ink (hereinafter, referred to as a recording liquid) in a chamber of a recording head, and the energy is applied. An apparatus for generating droplets may be used. A brief description of the device is provided by way of example and the practice of the invention is not limited by the following.

FIG. 1 shows an example of the structure of the head, which is the main part.
(A), FIG. 1 (b) and FIG. The head 13 includes a glass, ceramics, plastic plate or the like having a groove 14 through which ink passes, and a heating head 15 used for thermal recording (a thin film head is shown in the figure, but is not limited to this). And obtained by bonding. The heating head 15 includes a protective film 16 made of silicon oxide or the like, aluminum electrodes 17-1 and 17-2, a heating resistor layer 18 made of nichrome or the like, a heat storage layer 19, and a substrate having good heat dissipation such as alumina. It consists of 20.

The ink 21 has a discharge orifice (fine hole) 2
The meniscus 23 is formed by the pressure P.

When an electric signal is applied to the electrodes 17-1 and 17-2, the area of the heating head 15 indicated by n rapidly generates heat, and bubbles are generated in the ink 21 in contact with the area, and the pressure is increased. As a result, the meniscus 23 protrudes, the ink 21 is discharged, and becomes a recording droplet 24 from the orifice 22 and flies toward the recording medium 25. FIG. 2 shows an external view of a multi-head in which many heads shown in FIG. 1A are arranged. The multi-head includes a glass plate 27 having a multi-groove 26,
It is formed by bonding a heating head 28 similar to that described in FIG.

FIG. 1A is a sectional view of the head 13 along the ink flow path, and FIG.
-It is a cut surface in the B line.

FIG. 3 shows an example of an ink jet recording apparatus incorporating such a head. In FIG. 3, reference numeral 61 denotes a blade serving as a wiping member, one end of which is held by a blade holding member and serves as a fixed end in the form of a cantilever. The blade 61 is provided at a position adjacent to a recording area of the recording head, and in the case of this example, is held in a form protruding into the movement path of the recording head. Reference numeral 62 denotes a cap, which is disposed at a home position adjacent to the blade 61 and has a configuration in which the cap moves in a direction perpendicular to the moving direction of the recording head to abut on the ejection surface to perform capping. Reference numeral 63 denotes an ink absorber provided adjacent to the blade 62, which is held in a form protruding into the movement path of the recording head, similarly to the blade 61. The blade 61, the cap 62, and the absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the absorber 6
3 removes moisture, dust and dirt from the ink ejection port surface. Reference numeral 65 denotes a recording head which has ejection energy generating means and discharges ink on a recording material facing the ejection port surface where ejection ports are arranged to perform recording, and 66 denotes a mounting of the recording head 65 and movement of the recording head 65. Is a carriage for performing the following. The carriage 66 is slidably engaged with the 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 can move along 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 feed unit for inserting a recording material, and reference numeral 52 denotes a paper feed roller driven by a motor (not shown). With these configurations, the recording material is fed to a position facing the discharge port surface of the recording head, 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 returns to the home position at the end of recording or the like, the head recovery unit 64
The carriage 62 is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. As a result, the ejection port surface of the recording head 65 is wiped. When capping is performed with the cap 62 in contact with the ejection surface of the recording head 65, the cap 62 moves so as to protrude into the movement 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 position at the time of wiping described above. As a result, even 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 end of printing or at the time of ejection recovery, but also at a predetermined interval while the printing head moves through the printing area for printing. Position, and the wiping is performed along with the movement.

FIG. 4 shows an ink cartridge 4 containing ink supplied to the head via an ink supply tube.
FIG. 5 is a diagram showing an example of a fifth example. Here, reference numeral 40 denotes an ink bag containing the supply ink, and a rubber stopper 42 is provided at the tip of the ink bag.
Is provided. 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 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 the one in which they are integrated as shown in FIG. Can be

In FIG. 5, reference numeral 70 denotes an ink jet cartridge, which contains an ink absorber impregnated with ink, and the ink in the ink absorber is supplied from a head unit 71 having a plurality of orifices. It is configured to be ejected as ink droplets. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere.

This ink jet cartridge 70 is
It is used in place of the recording head 65 shown in FIG. 3, and is detachable from the carriage 66.

[0052]

【Example】

(Example 1) (Preparation of pigment dispersion) Styrene-acrylic acid-ethyl acrylate copolymer 0.7 part (acid value 174, average molecular weight 9000) monoethanolamine 0.4 part ion-exchanged water 73.9 parts Ethylene glycol 5 parts The above components are mixed and heated to 70 ° C. in a water bath to completely dissolve the resin components. At this time, when the concentration of the resin to be dissolved is low, the resin may not be completely dissolved, so that when dissolving the resin, a high-concentration solution may be prepared in advance, and the desired resin solution may be adjusted by dilution. . Hostap to this solution
15 parts of erm Pink E (manufactured by Hoechst) and 5 parts of ethanol were added, and after premixing for 30 minutes, dispersion treatment was performed under the following conditions.

Disperser Sand grinder (made by Igarashi Kikai) Grinding media Zirconium beads 1 mm diameter Filling rate of grinding media 60% (volume) Grinding time 3 hours Further centrifugation (12000 RPM, 20 minutes) is performed to remove coarse particles. To obtain a pigment dispersion.

(Preparation of Recording Liquid) The above pigment dispersion 40 parts Glycerin 10 parts Ethylene glycol 10 parts Ethanol 4 parts Deionized water 36 parts The above components were mixed and stirred for 1 hour to obtain a recording liquid (A). (Example 2) (Preparation of pigment dispersion) Acrylic acid-butyl acrylate-methyl methacrylate copolymer (acid value 80, average molecular weight 6700) 1 part Monoethanolamine 0.5 part Ion exchange water 72.5 parts Diethylene glycol 6 parts The above components are mixed and heated to 70 ° C. in a water bath to completely dissolve the resin components. Add Fuji Fast Red to this solution
Add 9 parts of 9900RM (manufactured by Fuji Dye) and 5 parts of ethanol,
After premixing for 30 minutes, dispersion treatment was performed under the following conditions.

Disperser Sand grinder (made by Igarashi Kikai) Grinding media Glass beads 0.8 mm diameter Filling rate of grinding media 50% (volume) Grinding time 3 hours Further centrifugation treatment (20,000 RPM, 20 minutes) is performed to remove coarse particles. This was removed to obtain a pigment dispersion.

(Preparation of recording liquid) 30 parts of the above pigment dispersion liquid 4 parts of thiodiglycol 1, 5 parts of 1,2,6-hexanetriol 10 parts of ethylene glycol 4 parts of 4 parts of isopropyl alcohol 47 parts of ion-exchanged water After stirring for a time, a recording liquid (B) was obtained. (Example 3) (Preparation of pigment dispersion) Styrene-maleic acid half ester-maleic anhydride copolymer (acid value 205, average molecular weight 7000) 0.6 parts KOH 0.5 parts ion-exchanged water 71.9 parts Ethylene glycol 5 parts The above components are mixed and heated to 70 ° C. in a water bath to completely dissolve the resin components. Add Hostaperm Red to this solution
15 parts of EG trans (manufactured by Hoechst) and 7 parts of ethanol were added, and after premixing for 30 minutes, dispersion treatment was performed under the following conditions.

Disperser Pearl Mill (made by Ashizawa) Pulverized media Glass beads 1 mm diameter Filling rate of pulverized media 70% (volume) Discharge speed 80 ml / min. Further, centrifugation treatment (12000 RPM, 20 minutes) is performed to remove coarse particles. To obtain a pigment dispersion. (Preparation of recording liquid) 35 parts of the above pigment dispersion liquid 12 parts glycerin 7 parts thiodiglycol 7 parts ethylene glycol 5 parts ethanol 5 parts ion-exchanged water 36 parts The above components were mixed and stirred for 1 hour to obtain a recording liquid (C). . (Comparative Example 1) Styrene-acrylic acid contained in the dispersion of Example 1
The recording liquid (D) was obtained in the same manner except that the ethyl acrylate copolymer was changed to 5 parts, monoethanolamine was changed to 2 parts, and ion-exchanged water was changed to 68 parts. (Comparative Example 2) The amount of the acrylic acid-butyl acrylate-methyl methacrylate copolymer contained in the dispersion of Example 2 was changed to 3 parts, monoethanolamine to 1 part, and ion-exchanged water to 70 parts. The recording liquid (E) was obtained with the same prescription, except that the recording liquid (E) was used. (Comparative Example 3) A recording liquid (F) was obtained with the same prescription, except that the amount of isopropyl alcohol used in the preparation of the recording liquid of Example 2 was changed to 0 parts and the amount of ion-exchanged water was changed to 51 parts. (Comparative Example 4) A recording liquid (G) was obtained in the same manner as in Example 3, except that the amounts of glycerin and thiodiglycol contained in the recording liquid were changed to 0 parts, and ion-exchanged water was changed to 55 parts.

An ink jet printer BJ-130 modified machine (manufactured by Canon) which uses the above-described recording liquids A to G and applies thermal energy to eject ink as a printer.
The following evaluation (T1 and T2) was performed using.

[0059]

[Table 1] T1: Driving conditions and ejection stability The driving voltage of the printer was set to 25 V, 27 V, and 30 V, and printing was performed at room temperature under two conditions of a frequency of 2 KHz and 4 KHz at each voltage. The presence or absence of non-ejection and the like was observed, and the ejection stability was evaluated.

.Largecircle .: Discharge is performed neatly from the first character, and there is no non-discharge, chipping, or printing disturbance during continuous printing.

；: The character portion is discharged neatly, but non-discharge is observed at several places in the solid printing portion.

Δ: If several characters are continuously printed even in the character portion, non-ejection occurs.

X: Significant ejection disturbance occurred from the first character, making it impossible to read the printed matter.

T2: Recoverability of clogging at the time of reprinting after printing is stopped for a long time After the printer is filled with a predetermined recording liquid and alphanumeric characters are printed continuously for 10 minutes, printing is stopped and capping is not performed. After standing for 7 days in the state, the nozzle clogging recovery operation was performed, and it was determined how many times the operation was performed to enable normal printing without blurring or chipping of characters. The leaving condition is 60 ° C,
At 10 + 5% RH, the driving conditions were 2 KHz and 30 V.

○: Normal printing is possible with 1 to 5 recovery operations. Δ: Normal printing is possible with 6 to 9 recovery operations. X: Normal printing is possible with 10 or more recovery operations.

[0066]

According to the present invention, it is possible to provide a magenta recording liquid which is excellent in the robustness and color tone of a printed matter, and which is suitable for a recording apparatus having various recording heads and using thermal energy. Further, it is possible to provide a recording method which is highly reliable and capable of high quality printing.

[Brief description of the drawings]

FIG. 1A is a diagram showing a configuration of a recording head applicable to the embodiment of the present invention. FIG. 2B is a diagram illustrating a configuration of a recording head applicable to the embodiment of the invention.

FIG. 2 is a diagram illustrating a configuration of a recording head applicable to the embodiment of the invention.

FIG. 3 is a diagram illustrating an example of an inkjet recording apparatus incorporating a recording head as illustrated.

FIG. 4 is a diagram illustrating an example of an ink cartridge.

FIG. 5 is a diagram illustrating an example of an ink cartridge integrated with a recording head.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-155262 (JP, A) JP-A-3-76768 (JP, A) JP-A-4-2488881 (JP, A) (58) Field (Int. Cl. ⁷ , DB name) C09D 11/00-11/20 CA (STN) REGISTRY (STN)

Claims (16)

(57) [Claims] Claims: 1. A pigment represented by the following general formula is the only colorant
It includes as a, and contain a water-soluble resin and an aqueous medium
A that inkjet recording liquid, the ratio between the pigment and the water-soluble resin 15 in a weight ratio: the inkjet recording liquid, characterized in that in the range 1:: 1 30 ## STR1 ## (Where R is H, CH ₃ or Cl) 2. The ink jet recording liquid according to claim 1 , wherein the content of the pigment is 3 to 30% by weight. 3. The ink jet recording liquid according to claim 2 , wherein the surface tension is 30 dyne / cm or more. 4. The ink jet recording liquid according to claim 1 , wherein the aqueous medium is a polyhydric alcohol or its alkyl ether and an aliphatic monohydric alcohol. 5. A composition containing at least 10% by weight of the polyhydric alcohol.
The ink jet recording liquid according to claim 4. 6. The ink jet recording liquid according to claim 4 , wherein the aliphatic monohydric alcohol has 1 to 4 carbon atoms. 7. The ink jet recording liquid according to claim 6 , wherein the aliphatic monohydric alcohol is ethyl alcohol or isopropyl alcohol. 8. An aliphatic monohydric alcohol containing 3 to 10% by weight.
The ink jet recording liquid according to claim 6 , comprising: 9. The ink jet recording liquid according to claim 4 , comprising 10 to 50% by weight of a polyhydric alcohol or an alkyl ether thereof. 10. The weight-average molecular weight of the water-soluble resin is 300.
The ink-jet recording liquid according to claim 1, wherein the amount is from 0 to 30,000. 11. The water-soluble resin having a weight average molecular weight of 500
The inkjet recording liquid according to claim 10 , wherein the amount is from 0 to 15,000. 12. The water-soluble resin is a styrene-acrylic acid copolymer, a styrene-acrylic acid-alkyl acrylate copolymer, a styrene-maleic acid copolymer, a styrene-maleic acid-alkyl acrylate copolymer. Styrene-methacrylic acid copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, The ink jet recording liquid according to claim 1 , which is a styrene-maleic anhydride-maleic acid half ester copolymer or a salt thereof. 13. A single colorant represented by the following general formula:
Containing a pigment, a water-soluble resin and an aqueous medium, the pigment and
The ratio with the water-soluble resin is 15: 1 to 30: 1 by weight.
The method for producing an inkjet recording liquid in the range of
Te, and the pigment and the water-soluble resin in a weight ratio of 15: 1 to 30: 1
Dispersed in the presence of an aqueous medium tone pigment dispersion in the ratio
And a step of further adding an aqueous medium to the pigment dispersion.
Inkjet recording liquid producing method characterized by: ## STR2 ## (Where R is H, CH ₃ or Cl) 14. The water-soluble resin is a styrene - acrylic acid copolymer, styrene - acrylic acid - acrylic acid alkyl ester copolymer, styrene - maleic acid copolymer, styrene - maleic acid - acrylic acid alkyl ester copolymerization Copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer The method for producing an ink jet recording liquid according to claim 13, which is a styrene-maleic anhydride-maleic acid half ester copolymer or a salt thereof . 15. An ink jet recording method, wherein thermal energy is applied to the recording liquid according to any one of claims 1 to 12 , and the recording liquid is ejected as ink droplets from an orifice and adhered to a recording material to perform recording. Method. 16. The ink jet recording method according to claim 15, wherein the recording method is an on-demand type recording method.