JP2000273373A - Recording liquid and ink jet recording method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide high-density recording with good print quality of recorded matter, excellent storage stability and water resistance, and excellent discharge durability in ink jet recording, etc. The present invention provides a recording liquid which gives a good printed matter without bleeding at the boundary of the recording liquid. SOLUTION: This is a recording liquid containing an aqueous medium, a coloring material, and a water-soluble polymer compound, and when the polymer compound is in a form of a free acid, a carboxylic acid based on all acidic groups in the polymer compound. A recording liquid, wherein the molar ratio of the groups is in the range of 0.1 or more and less than 1.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous medium recording liquid, for example, an ink jet recording liquid, or a recording liquid for a writing instrument, and particularly to a recording liquid suitable for ink jet recording.

[0002]

2. Description of the Related Art Conventionally, as a recording liquid for ink jet recording, an aqueous ink in which an acidic dye or a direct dye is dissolved in an aqueous medium, or a solvent-based ink in which an oil-soluble dye is dissolved in an organic solvent has been used. . Since the solvent-based ink uses a solvent, it has a problem in terms of environmental safety, and its use is limited because it is not suitable for use in offices and the like. On the other hand, water-based ink uses a water-soluble dye, especially when recorded on plain paper, there is a problem that the water resistance of the recorded matter is inferior,
The recorded matter of the ink using these dyes is insufficient in light resistance. Further, such a problem occurs not only in the ink jet but also in the recording liquid for a writing instrument.
In order to solve the above-mentioned problems, a pigment having excellent water resistance and light fastness is used as a coloring material, and an aqueous dispersion ink in which the pigment is dispersed in an aqueous medium is partially used. However, conventional aqueous dispersion inks of pigments have insufficient storage stability and print density. In US Pat. No. 5,708,095, a recording liquid containing a polymer containing a carboxylic acid group and a sulfonic acid group is used, but a polymer having a molar ratio of carboxylic acid group to all acidic groups of 1/11 is used. It is only used.

[0003]

SUMMARY OF THE INVENTION The present invention is intended for use in ink jet recording of any type (continuous type, on-demand type, piezo type, thermal type, etc.) or for writing instruments, even when recording on plain paper. A high-density recording is possible with good print quality, good storage stability, good lightfastness, waterfastness such as waterfastness, etc. It is intended to provide.

[0004]

Means for Solving the Problems The present inventors have conducted various studies on the storage stability and the improvement of print density of an aqueous dispersion ink for a recording liquid. As a result, a carboxylic acid group was added to the polymer compound as a polymer dispersant. Is a recording liquid using a compound containing a specific ratio of is excellent in storage stability, discharge stability, it has been found that the recorded matter recorded using this shows a high print density, leading to the present invention. . That is, the gist of the present invention is a recording liquid containing an aqueous medium, a coloring material and a water-soluble polymer compound, wherein when the polymer compound is in the form of a free acid, the total acidity in the polymer compound is The molar ratio of the carboxylic acid group to the group is in the range of 0.1 or more and less than 1.0.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The recording liquid of the present invention is a recording liquid containing an aqueous medium, a coloring material, and a water-soluble polymer compound. The water-soluble polymer compound in the present invention contains an acidic group other than a carboxylic acid group in the molecule, such as a sulfonic acid group or a phosphoric acid group,
The molar ratio of the carboxylic acid group to the total acidic group in the polymer compound is 0.1 or more and less than 1.0, and the recording liquid containing such a polymer has a storage stability, a printing density, and a boundary with other colors. It is preferable in terms of bleeding, more preferably 0.2 or more and 0.9 or less, and particularly preferably 0.4 or more and 0.9 or less. Also,
Similarly, the carboxylic acid group is COOH, the sulfonic acid group is SO ₃ H, the phosphate group is PO ₄ H ₂ , and the other acidic groups are also the same. The total content of these free acid acidic groups in the polymer compound is 10%. The content is preferably from 70% by weight to 70% by weight, more preferably from 15% by weight to 60% by weight, and particularly preferably from 17% by weight to 50% by weight.

When the polymer compound is in the form of a free acid, any compound may be used as long as it contains a carboxylic acid group and another acidic group, for example, a sulfonic acid group and / or a phosphoric acid group. Those having a hydrophobic group are preferred in terms of storage stability. Examples of the hydrophobic group include a functional group having an aromatic ring such as a phenyl group, a benzyl group, and a naphthyl group which may be substituted, a branched or cyclic or substituted or unsubstituted alkyl group or alkenyl group having 4 or more carbon atoms. Alkynyl group. Acrylic acid, methacrylic acid, (anhydride) maleic acid, itaconic acid, 2-methyleneglutaric acid, and the like can be used to introduce the carboxylic acid group, and 2- (meth) acrylamide-2-
Methyl-1-propanesulfonic acid, 2- (meth) acrylamide-1-ethylsulfonic acid, 2- (meth) acrylate-2-methyl-1-propanesulfonic acid, 2-
(Meth) acrylate-1-ethylsulfonic acid, styrenesulfonic acid and the like can be used.
(Meth) acrylamido-2-methyl-1-propanephosphoric acid, 2- (meth) acrylamido-1-ethylphosphoric acid, 2- (meth) acrylate-2-methyl-1-propanephosphoric acid, 2- (meth) acrylate -1-Ethyl phosphoric acid and the like can be used. (Here, “(meth) acryl” refers to acryl or methacryl.)

The polymer compound is a block polymer,
Although any of a graft polymer and a random polymer can be used, a graft polymer and a random polymer are preferred mainly in view of production cost, and a random polymer is particularly preferred. The weight average molecular weight of the polymer compound is preferably from 1,000 to 50,000, more preferably from 2,000 to 30,000, particularly preferably from 2,000 to 20,000. These polymer compounds can be used as dispersants, and can be used in the form of alkali metal salts such as Li, Na, and K, and organic amine salts such as ammonia, dimethylamine, monoethanolamine, diethanolamine, and triethanolamine.

The amount of the specific polymer compound of the present invention used is
1 to 100% by weight, preferably 3 to 50% by weight, more preferably 3 to 50% by weight, based on the weight of the water-insoluble colorant, in terms of storage stability, ejection stability, print density, and bleeding at the boundary with other colors. ~
30% by weight is particularly preferred. In the present invention, a water-insoluble coloring material can be preferably used as the coloring material. Examples of the water-insoluble coloring material that can be used include organic pigments, inorganic pigments, disperse dyes, oil-soluble dyes, and the like, and specific examples include the following.
Specific examples of the pigment used in the yellow ink, C.
I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 1
7, 73, 74, 75, 83, 93, 95, 97, 98, 114, 128, 129
, 151, 154 and the like.

Specific examples of pigments used in magenta ink include CI Pigment Red 5, 7, 12, 48.
(Ca), CI48 (Mn), 57 (Ca), 57: 1, 112, 123, 168,
184, 202 and the like. Specific examples of the pigment used for the cyan ink include CI Pigment Blue 1, 2, and
3, 15: 3, 15:34, 16, 22, 60, 4, 60 and the like. In addition to the above, CI Pigment Reds 209, 122, 22
4, 177, 194, CI Pigment Orange 43, CI Bat Violet 3, CI Pigment Violet 19, 2
3, 37, CI Pigment Green 36, 7, CI Pigment Blue 15: 6, 209, etc. can also be used.

As the oil-soluble dye, CI Solvent Yellow 16, 21, 25, 29, 33, 56, 82, 88, 89, 150, 151,
163, CI Solvent Red 24, 27, CI Solvent Blue 14, 25, 38, 48, 67, 68, 70, 132, CI Solvent Black 3, 5, 7, 27, 28, 29, 34, etc. can be used,
Oil yellow 105, 107, Balifast yellow 1101, 1105, Balifast red 1306, Balifast blue 1603, 1607, 2610, Balifast black 18
02, 1807, 3830 (all manufactured by Orient Chemical Co., Ltd.), Aizen Spiron Yellow GRLH, 3RH, Aizen Spiron Blue GNH, 2BNH, BPNH, Aizen Spiron Black MH, GMH (above, manufactured by Hodogaya Chemical Co., Ltd.) ),
Oleosol Blue G, Oleosol Black AR (all produced by Taoka Chemical Industry Co., Ltd.), and Orasol Black RL1 (made by Ciba Geigy). As a disperse dye
CI Disperse Yellow 3, 82, 54, CI Disperse Red 60, 191 and Disperse Vilet 57.

In the present invention, carbon black such as acetylene black, channel black and furnace black can be used. Usable carbon black has a DBP oil absorption of usually from 60 to 200 ml / 100 g or more, and preferably 90 ml / 100 g or more in terms of storage stability and print density, and 140 ml / 10 g or more.
0 g or more is particularly preferred. The volatile content is usually preferably in the range of 8% by weight or less, and particularly preferably 4% by weight or less. In addition, the BET specific surface area is 150 m ² /
g or more is preferable in terms of storage stability and print density.
more preferably a ^{m 2 / g~1000m 2 / g,} 2
Those of 00m ² / g~400m ² / g is particularly preferred.
The primary particle size is preferably 40 nm or less in terms of storage stability, ejection stability, and print density, and particularly preferably 20 nm or less. Here, the DBP oil absorption of the carbon black is a value measured by JIS K6221A method, the volatile content is a value measured by JIS K6221 method,
The primary particle diameter is an arithmetic mean diameter measured by an electron microscope.

[0012] As the above carbon black, # 2
600, # 2300, # 990, # 980, # 960, # 950, # 900, # 850,
# 750, # 650, MCF-88, MA-600, # 95, # 55, # 52, # 47
, # 45, # 45L, # 44, # 40, # 33, # 32, # 30, # 25
, # 20, # 10, # 5 (Mitsubishi Chemical), Color Black
FW1, FW2, FW2V, FW18, FW200, Special Blaek4, 4
A, 5, 6, 100, 250, 350, 550, S160, S170, Pri
ntex U, V, 140U, 140V, 95, 90, 85, 80, 75, 45, 4
0, P, 60, 300, 30, 35, 25, 200, A, G, L6, L
(Made by Degussa), Regal415R, 330R, 250R, 995
R, Monarch800, 880, 900, 460, 280, 120 (or higher,
Cabot), Raven 850, 780ULTRA, 760ULTRA, 79
0 ULTRA, 520, 500, 410, 420, 430, 450, 460,
890, 1020 (all made in Colombia) and the like are specific examples. In the present invention, among the water-insoluble coloring materials described above, carbon black is particularly preferred. The amount of the water-insoluble coloring material used is preferably 1 to 10% by weight based on the total weight of the recording liquid, but is preferably 3 to 8% by weight.

The water-insoluble coloring material used in the recording liquid of the present invention may be obtained by chemically treating a water-insoluble coloring material (oxidation treatment, fluorination treatment, etc.), dispersant, surfactant A material obtained by physically or chemically bonding the above components (grafting treatment, a dispersant previously adsorbed before dispersion, or the like) may be used. In the recording liquid of the present invention, other additives such as a surface tension adjusting agent and a preservative may be used. Examples of additives that can be used include various anionic surfactants,
Examples include nonionic surfactants, cationic surfactants, amphoteric surfactants, and high molecular dispersants other than the high molecular compounds defined above.

Examples of the anionic surfactant include fatty acid salts, alkyl sulfate salts, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfosuccinates, alkyl diphenyl ether disulfonates, alkyl phosphates, and polyoxyethylene alkyl. Sulfates, polyoxyethylene alkylaryl sulfates, alkane sulfonates, naphthalenesulfonic acid formalin condensates, polyoxyethylene alkyl phosphates, N-methyl-N-oleoyl-taurate, α- Olefin sulfonates and the like.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene derivatives, oxyethylene, oxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan Examples include fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters, and polyoxyethylene alkylamines.

Examples of the cationic surfactant and the amphoteric surfactant include alkylamine salts, quaternary ammonium salts, alkylbetaines, and aminooxides. If necessary, a polymer dispersant other than the above-described specific polymer compound may be further added to the recording liquid of the present invention. The polymer to be used may be any of anionic, cationic, amphoteric and nonionic polymers, but is preferably a water-soluble polymer. Among them, polymers having an anionic water-soluble group such as carboxylic acid (salt), sulfonic acid (salt), and phosphoric acid (salt), and nonionic polymers are preferable. Copolymers can also be used as these polymers. Among them, a polymer having a sulfonic acid group or a carboxylic acid group is preferable in terms of ejection stability and storage stability. When an anionic copolymer is used, the hydrophobic group in the anionic polymer may be a functional group having an aromatic ring such as a phenyl group, a benzyl group or a naphthyl group which may be substituted, or a branched group having 4 or more carbon atoms. And an optionally substituted alkyl group, alkenyl group and alkynyl group.

The anionic polymer used in the present invention is, specifically, (α-methyl) styrene / acrylic acid copolymer, (α-methyl) styrene / acrylic acid / acrylate copolymer, (α-methyl) styrene / maleic acid copolymer, (α-methyl) styrene / maleic acid / acrylate copolymer, (α-methyl) styrene /
Methacrylic acid copolymer, (α-methyl) styrene / methacrylic acid / acrylic acid ester copolymer, (α-methyl) styrene / methacrylic acid / methacrylic acid ester copolymer, (α-methyl) styrene / maleic acid half Ester copolymer, (α-methyl) styrene / styrenesulfonic acid (salt copolymer, vinylnaphthalene / maleic acid copolymer, vinylnaphthalene / acrylic acid copolymer,
Examples include naphthalene sulfonic acid formalin condensate, lignin sulfonic acid, and salts thereof.

[0018] Of these tones well, since preference is given to those in obtaining a printed matter does not flow in the water of the anionic polymer of the present invention is not colored, the maximum value of absorbance at a range of 380~780nm is 0.05 g ^- preferably ¹ · l · cm ^-1 or less things, 0.01g ^-1 · l · cm ^-1 following are particularly preferred. The sulfonic acid (salt) group content of the polymer having the sulfonic acid (salt) is preferably such that the amount of the sulfonic acid group in the form of free acid is 10% by weight or more and 40% by weight.
The content is more preferably from 0% by weight to 30% by weight. The acid value of the polymer having the carboxylic acid (salt) is preferably 130 or more and 700 or less in terms of storage stability and ejection stability, more preferably 200 or more and 700 or less, and 20 or less.
It is particularly preferably from 0 to 500.

As the other polymer dispersant which can be used in combination with the specific polymer compound of the present invention, any of a block polymer, a graft polymer and a random polymer can be used. Random polymers are preferred. The weight average molecular weight of the polymer dispersant is preferably 50,000 or less from the viewpoint of ejection stability, and more preferably 15,000 or less. These polymer dispersants can be used in the form of alkali metal salts such as Li, Na, and K, and organic amine salts such as ammonia, dimethylamine, monoethanolamine, diethanolamine, and triethanolamine. Among these, anionic surfactants, cationic surfactants and polymer dispersants different from the specific polymer of the present invention are particularly excellent.

In the present invention, a nonionic additive may be used. As the nonionic additive, a nonionic additive having an alkylene oxide structure is preferable. Among them, a nonionic additive having an ethylene oxide structure or a propylene oxide structure is preferable in terms of storage stability and printing density, and among them, HLB is preferable. Is more preferably 9 to 17. Those having an HLB of 10 to 16 are particularly preferred. Specifically, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene tridecyl ether, polyoxyethylene cetyl ether, polyoxyethylene cetyl ether Oxyethylene stearyl ether, polyoxyethylene alkylamine, amino polyoxyethylene, sorbitan fatty acid ester, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, naphthol ethylene oxide Adduct, acetylene glycol ethylene oxide adduct, bisphenol A ethylene Kishido adduct, oxyethylene oxypropylene block polymers, acetylene glycol ethylene oxide adducts.

The aqueous medium used in the recording liquid of the present invention is mainly water, but it is preferable to use a water-soluble organic solvent added to water. Examples of the water-soluble organic solvent include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (# 200, # 400), glycerin, and ethylene oxide adducts of the above glycols (specific examples: Liponic EG-1 (LiPo Chemical product name), etc.),
Examples of the above glycols include alkyl ethers, N-methylpyrrolidone, 1,3-dimethylimidazolinone, thiodiglycol, 2-pyrrolidone, sulfolane, dimethylsulfoxide, diethanolamine, triethanolamine, methanol, ethanol, and isopropanol. The amount of the water-soluble organic solvent used is usually 5 to 30% by weight based on the total weight of the recording liquid, but 10 to 20% by weight is preferable in terms of storage stability.

In the recording liquid of the present invention, in addition to the above components, a water-soluble resin and a fungicide (specific examples: ProxelBDN, BD20, GXL, LV, XL)
-2, TN (trade name of Zeneca), bactericide, pH adjuster, urea, etc. may be added as necessary. As a dispersing machine used for preparing the recording liquid of the present invention, besides a ball mill, a roll mill, and a sand grind mill, a jet mill such as a nanomizer and an ultimizer that can be pulverized without using a medium is used. Alternatively, a jet mill with less contamination from media is preferred. When using a bead mill such as a sand grind mill, glass beads, zirconia beads and the like can be used. After this grinding and dispersion treatment, coarse particles are removed using a filter or a centrifuge. In addition, since the grinding and dispersion treatment can be efficiently performed by adjusting the concentration of the recording liquid, it is preferable to dilute the processing liquid prepared at a high concentration with an aqueous medium to adjust the concentration of the recording liquid. The average particle size of the water-insoluble coloring material in the recording liquid is 0.01 to 0.1.
It is preferable to adjust the thickness to a range of 4 μm from the viewpoint of dispersion stability and ejection stability. Furthermore, the maximum particle size of the water-insoluble coloring material is 5 μm
The following is preferable in terms of dispersion stability and ejection stability.

As the specific polymer compound, water-insoluble colorant, surfactant, other additives and organic solvent of the present invention, one kind may be used alone, but in some cases, two or more kinds may be used. By using together, further effects can be obtained. Further, the recording liquid of the present invention can be used for recording not only on plain paper but also on other recording materials (coated paper, glossy paper, synthetic paper, OHP sheet, etc.).

[0024]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which, however, are not intended to limit the scope of the invention. In the following examples, “parts” and “%” are based on weight.

Production Example 1 A four-necked flask equipped with a reflux condenser, a thermometer, a glass tube for purging nitrogen, and a stirrer was charged with 50 parts of styrene and acrylamido-2-methylpropanesulfonic acid (hereinafter referred to as AM).
PS), 30 parts of acrylic acid, 20 parts of acrylic acid, 4 parts of lauryl mercaptan, and 300 parts of ethanol.
(Azoisobutyronitrile) (2 parts) was added, and the mixture was refluxed at 80 ° C. under a nitrogen stream. Two hours later, 0.3 parts of AIBN was added, and after another two hours, 0.3 parts of AIBN was added, and polymerization was further performed for 4 hours. Next, under cooling, an aqueous solution of sodium hydroxide corresponding to 90 mol% of AMPS and acrylic acid was dropped into the flask and neutralized. The ethanol in this solution was removed to obtain an anionic resin aqueous solution containing a polymer compound. (Here, the molar ratio of the carboxylic acid groups in the form of free acid to the total acidic groups in the polymer compound is 0.4. The carboxylic acid group in the polymer compound is 12.6% by weight,
The sulfonic acid group is 11.7% by weight, and the content of all acidic groups in the polymer compound is 24.3% by weight. )

Production Example 2 Production Example 2 was repeated except that the monomers used in the polymerization were 40 parts of styrene, 20 parts of 2,4-dihydroxybenzophenone adduct of glycidyl methacrylate, 30 parts of AMPS, and 10 parts of acrylic acid. Similarly, an aqueous anionic resin solution was obtained. (Here, the molar ratio of the carboxylic acid groups in the form of free acid to the total acidic groups in the polymer compound is 0.25. The carboxylic acid groups in the polymer compound are 6.2% by weight, Groups are 11.7% by weight, and the content of all acidic groups in the polymer compound is 17.9% by weight.)

Example 1 (Preparation of recording liquid)

[0028]

[Table 1] Composition of recording liquid Amount (parts) Furnace Carbon Black manufactured by Mitsubishi Chemical Corporation (DBP oil absorption: 147 ml / 100 g, volatile matter: 3.7 wt%, pH 7.3, BET specific surface area: 294 m ² / g, primary) Particle size 14 nm) 4 Anionic water-soluble resin aqueous solution (solid content 25%) 2.4 1,3-dimethylimidazolidinone 4 ion-exchanged water 33.6 ─────────────── Total 44

The above components were placed in a cylindrical stainless steel container, and subjected to a dispersion treatment for 3 hours using a sand grinder together with 152 parts of zirconia beads (product of Toray) having an average diameter of 0.5 mm. 4 parts of glycerin, 3 parts of ethanol and 49 parts of ion-exchanged water were added to the obtained liquid. This solution was Pressure filtration was performed using a 5C filter paper, and the liquid obtained here was used as a recording liquid.

(Printing Test) The recording liquid obtained by the method described in Example 1 was filled in a washed Hewlett-Packard DeskWriter660C black cartridge (HP51629A), and a printer (Hewlett-Packard DeskWriter660).
Set to C). In this state, electrophotographic paper (Xero
(x4024 paper, Xerox product) was solid printed, showing stable and good dischargeability without clogging and the like, and a printed matter of good print quality was obtained.

(Evaluation of Print Density) The density of the printed matter obtained in the above print test was measured using a Macbeth reflection densitometer (RD914). The results were classified as follows and are shown in Table 1 below.

[0032]

[Table 2] ── ── OD 1.6 or more ── ── OD 1.5 or more and less than 1.6 ── ＯＤ OD 1.4 or more and less than 1.5 × 未 満 OD less than 1.4

(Water Resistance Test) The printed matter obtained in the printing test was immersed in tap water taken in a beaker for 5 seconds. After drying the printed matter,
The presence or absence of character stain was visually evaluated. The results were classified as follows and are shown in Table 1 below.

[Table 3] ○ 字 Almost no dirt △ ── Slight dirt but no problem in practical use × ── Dirt is severe

(Evaluation of Bleeding Boundary with Other Colors) After the above-described printing test, a printing pattern in which a solid of yellow, magenta, and cyan contacts a solid of black was printed on an electrophotographic paper (Xerox).
The printing was performed on 4024 paper (Xerox product) (the used color cartridge (color ink) was a color cartridge (HP51649A) for DeskWriter 660C manufactured by Hewlett-Packard). The results were classified as follows and shown in Table 1 below.

[0035]

[Table 4] ○: There is almost no blur at the boundary between the solid color (single color) portion and the black ink solid portion. Δ: There is blur at the boundary between the solid color (monochromatic) portion and the black ink solid portion, but there is a practical problem. None ×: The boundary between the solid color (monochromatic) area and the black ink solid area has severe bleeding

(Measurement of particle size distribution) The obtained recording liquid is used as it is in a particle size distribution meter (MicrotracUPA (Nikkiso sales)).
The particle size distribution was measured. Measurement condition

[0037]

[Table 5] Transparent Particles: No, Spherical Particles:
No, Particle Refractive Index: 1.81 Particle Density: 1.86 Fluid Refractive Index: 1.33 High Temp: 30.0 ℃ Viscosity: 0.797 cP Low Temp: 20.0 ℃ Viscosity: 1.002 cP Run Time: 300 (sec), Number of Runs: 2

The average value of the two measurements under the above measurement conditions was taken as the value of the particle size distribution of the recording liquid, and
% Diameter (D50) was defined as the average particle diameter of the recording liquid. The average particle size is shown in Table 1 below.

(Storage stability test)
After storing for 1 week at room temperature and returning to room temperature after storage, the particle size distribution of the recording liquid was measured by the same method as described above. Further, the total difference between the above particle size distribution measurement results and the particle size distribution after storage at 70 ° C. for one week was determined. The results are shown in Table 1 below.

Example 2 (Preparation of recording liquid) Example 1 was repeated except that an aqueous solution of an anionic resin (solid content 25% by weight) was used instead of the aqueous solution of anionic resin (solid content 25% by weight).
A recording liquid was obtained in the same manner as described above. A printing test was performed in the same manner as in Example 1. As a result, a stable and good ejection property without clogging or the like was exhibited, and a printed matter having good printing quality was obtained.
Print density evaluation, water resistance test, border bleeding evaluation with other colors,
The results of particle size distribution measurement and storage stability test performed in the same manner as in Example 1 are shown in Table 1 below.

[0041]

[Table 6]

[0042]

According to the present invention, a printed matter having good print quality, good storage stability and good water resistance even when recorded on plain paper can be obtained for ink-jet recording or writing instruments. At the same time, it is possible to obtain an aqueous dispersion ink having good ejection properties, high print density, and little bleeding at the boundary with other color inks. Since the present invention has the above characteristics, it is not limited to ink jet and writing instruments,
It can also be used as a recording liquid for other uses.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tetsuro Murayama 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation Yokohama Research Laboratory F-term (reference) 2C056 EA05 EA13 FC02 2H086 BA53 BA55 BA59 BA60 4J039 AD03 AD09 AD10 AD12 AD13 AD14 AD17 AF07 BA04 BA29 BE01 BE07 BE08 BE22 CA06 EA15 EA16 EA17 EA20 EA35 EA38 EA42 EA44 GA24

Claims (8)

[Claims] 1. A recording liquid containing an aqueous medium, a coloring material and a water-soluble polymer compound, wherein when the polymer compound is in the form of a free acid, a carboxylic acid for all acidic groups in the polymer compound is used. A recording liquid, wherein the molar ratio of the acid group is in the range of 0.1 or more and less than 1.0. 2. The recording liquid according to claim 1, wherein the polymer compound contains a sulfonic acid group. 3. The recording liquid according to claim 1, wherein the polymer compound contains a phosphate group. 4. The amount of all acidic groups in the polymer compound is 10
The recording liquid according to any one of claims 1 to 3, wherein the content of the recording liquid is from 70 to 70% by weight. 5. The recording liquid according to claim 1, wherein the coloring material is a water-insoluble coloring material. 6. The recording liquid according to claim 5, wherein the water-insoluble colorant is carbon black. 7. The cumulative difference between the particle size distribution immediately after preparation of the recording liquid and the particle size distribution after storing the recording liquid at 70 ° C. for one week is 2
The recording liquid according to any one of claims 1 to 6, which is 0% or less. 8. An ink jet recording method for performing recording by discharging droplets of a recording liquid, wherein the recording liquid is used as the recording liquid.
7. An ink jet recording method, comprising using the recording liquid according to 7.