JP2001239744A - Ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording method, in which the blocking properties of the nozzle of an ink jet head are small and no turning of the flying direction of liquid drops develops even when a recording speed is increased. SOLUTION: With a head driven by a driving frequency of 15 kHz or higher, a recording is performed by discharging an ink, which includes carbon black, the volatile component of which is 15 mass % or less and the nitrogen adsorption specific surface area of which is 100 m2/g or more, a dispersant and a solvent in this ink jet recording method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet recording method, and more particularly, to an ink-jet recording method using a water-based pigment ink which is less likely to bend droplets and clog the head even when recording is performed with a head having a large driving frequency. The present invention relates to an inkjet recording method.

[0002]

2. Description of the Related Art An ink jet recording method is capable of recording a high-definition image with a relatively simple apparatus, and is rapidly developing in various fields. 2. Description of the Related Art Printers employing an ink jet recording system are manufactured in a wide range of fields, and the types of inks are also diversified according to the intended use. The ink used in the inkjet recording method includes a water-soluble dye ink, an oil-soluble dye ink, a water-soluble pigment ink, an oil-soluble pigment ink, and the like depending on the type of the solvent and the coloring material used. I have. Among them, water-soluble pigment inks are mainly water or water-soluble solvents and have a low environmental impact. Also, since colorants are pigments, their light resistance is relatively strong, so posters and electric decorations to be displayed outdoors can be used. It is being used widely, from systems for creating printers to printers for office use. On the other hand, pigment ink has a problem that clogging at nozzles is more likely to occur than dye ink.

On the other hand, ink jet recording has a drawback that the recording speed is slower than that of the electrophotographic system or the fusion heat transfer system. On the other hand, techniques for increasing the driving frequency per nozzle and attempts to increase the number of nozzles per color have been made, and the recording speed has been rapidly improved. However, a new problem is that when the driving frequency is increased, the droplet is likely to bend in the flight direction. In particular, when the driving frequency exceeds 15 kHz, the occurrence of bending is remarkable,
It was a problem.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to reduce the clogging of an ink jet head nozzle and to bend the droplet in the flight direction even when the recording speed is increased. An object of the present invention is to provide an ink jet recording method that does not cause a problem.

[0005]

The above object of the present invention is attained by the following constitutions.

[0006] 1. Recording is performed by ejecting an ink containing carbon black having a volatile component of 15% by mass or less and a nitrogen adsorption specific surface area of 100 m ³ / g or more, a dispersant, and a solvent by a head driven at a drive frequency of 15 kHz or more. An inkjet recording method characterized by performing the following.

[0007] 2. 2. The ink jet recording method according to claim 1, wherein the carbon black has a nitrogen adsorption specific surface area of 150 m ³ / g or more.

[0008] 3. 2. The ink jet recording method according to claim 1, wherein the nitrogen specific surface area of the carbon black is 200 m ³ / g or more.

4. In a head driven at a driving frequency of 15 kHz or more, the volatile component is 15% by mass or less, and D
Ink jet recording method and performing recording by BP oil absorption of ejecting an ink containing 70cm ^3/100 g or more of the carbon black, dispersing agent and a solvent.

[0010] 5. 4, wherein the DBP oil absorption of the carbon black is 80 cm ^3/100 g or more
The ink-jet recording method as described above.

6. A head driven at a driving frequency of 15 kHz or more discharges ink containing carbon black having a volatile component of 15% by mass or less and a primary particle size of 30 nm or less, a dispersant, and a solvent to perform recording. Characteristic ink jet recording method.

7. The carbon black has a primary particle size of 2
7. The ink-jet recording method according to 6, wherein the thickness is 0 nm or less.

8. The carbon black has a primary particle size of 5
7. The ink jet recording method according to 6, wherein the thickness is not more than 15 nm.

9. The inkjet recording method according to any one of claims 1 to 8, wherein the volatile component is 8% by mass or less.

10. A head driven at a driving frequency of 15 kHz or more contains a water-soluble resin, a pigment, and a solvent, and the content ratio of the pigment to the water-soluble resin is 1: 1 by mass.
An ink jet recording method, wherein the recording is performed by ejecting an ink of up to 15: 1.

11. The ink jet recording method according to claim 10, wherein the content ratio of the pigment and the water-soluble resin in the ink is 2: 1 to 10: 1 by mass ratio.

[12] An ink jet recording method comprising: performing recording by ejecting an ink containing a dispersant, a pigment, and a solvent and having an average particle diameter of the pigment of less than 100 nm using a head driven at a driving frequency of 15 kHz or more.

13. The pigment of the ink has an average particle size of 75
13. The inkjet recording method according to 12, wherein the particle diameter is not more than nm.

14. The pigment of the ink has an average particle size of 20.
13. The inkjet recording method according to 12, wherein the thickness is from 75 to 75 nm.

15. 15. The ink jet recording method according to any one of 1 to 14, wherein the recording is performed by a head driven at a driving frequency of 20 kHz or more.

16. 16. The ink jet recording method according to any one of 1 to 15, wherein the recording method is an on-demand method.

Hereinafter, the present invention will be described in detail. In the present invention, printing is performed by ejecting ink having the above-described characteristics using an inkjet head driven at a driving frequency of 15 kHz or more per nozzle. In particular, it is preferable that the driving frequency of the ink jet head is 20 kHz or more in that the recording speed is improved.

In the present invention, the recording system is preferably an on-demand system, and any on-demand ink jet recording system can be handled. Examples of the on-demand method include an electric-mechanical conversion method (for example, a single-cavity type, a double-cavity type, a bender type, a piston type, a shared mode type, a shared wall type, and the like), and an electro-thermal conversion method (for example, thermal inkjet). Mold, bubble jet type, etc., electrostatic suction type (for example, electric field control type, slit jet type, etc.), and discharge type (for example, spark jet type, etc.) can be mentioned as specific examples.

The pigment according to the present invention will be described. As the pigment according to the present invention, conventionally known organic and inorganic pigments can be used. For example, azo pigments such as azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc .; phthalocyanine pigments, perylene and perylene pigments; Dye lakes such as cyclic pigments, basic dye lakes, acid dye lakes, nitro pigments, nitroso pigments,
Organic pigments such as aniline black and daylight fluorescent pigments; and inorganic pigments such as carbon black.

The content of the pigment according to the present invention with respect to the total amount of the ink is preferably from 0.1 to 20% by mass, and more preferably from 0.3 to 10% by mass.

In the ink jet recording methods according to claims 1 to 9, 15 and 16 of the present invention, in order to obtain the effects described in the present invention, it is essential to use carbon black having a specific characteristic value. Hereinafter, the characteristic values will be described.

The volatile component of carbon black means a value obtained by the following measuring method. That is, a dry sample of carbon black is packed in a platinum crucible or a porcelain crucible of the same shape and the same capacity with a dropping lid by shaking to a size not exceeding 2 mm below the lid, and weighing the mass. Put this in an electric furnace, heat it at 950 ± 25 ° C for exactly 7 minutes, take it out, let it cool down to room temperature in a digitizer, weigh the mass after heating, and determine the volatile matter by the following formula. calculate.

[0028] V (%) = ((W D -W R) / W D) × 100 where, V: volatile component (mass%), W _D: mass of dry sample (g), W _R: after heating Is the mass (g) of the sample.

The volatile matter of the carbon black of the present invention is 15
% By mass or less, preferably 8% by mass or less.

The DBP oil absorption of carbon black is defined as J
This is a characteristic value calculated based on the test method shown in IS K 6217 (1997).

The DBP oil absorption of the carbon black according to the present invention, but is 70cm ^3/100 g or more, preferably 80 cm ^3/100 g or more.

The nitrogen adsorption specific surface area of carbon black is
It is calculated based on the test method shown in JIS K 6217 (1997).

The carbon black according to the present invention has a nitrogen specific surface area of 100 m ² / g or more, preferably 150 m ² / g or more, more preferably 200 m ² / g or more.
m ² / g or more.

The primary particle size of carbon black is an arithmetic average particle size obtained from an image observed using a scanning electron microscope. The primary particle size of the carbon black according to the present invention is 30 nm or less, preferably 20 nm or less, and more preferably 5 to 15 nm.

As the carbon black used in the present invention, for example, MA7, MA8, # 2200B (above,
Mitsubishi Kasei), RAVEN 1255 (Colombia),
REGAL400R, MOGUL L (Cabot), Color BlackFW1, Color B
black FW18, Color Black S17
0, Color BlackS150, Printex
Commercial products such as U (manufactured by Degussa) can be used, and those newly manufactured for the purpose of the present invention can also be used.

The carbon black according to the present invention is generally produced by a channel black method or a furnace black method. The channel black method is a production method in which natural gas, town gas, and hydrocarbons are partially burned as raw materials to collide with a cold surface, and the furnace black method is a natural gas or petroleum fraction that is kept in a high-temperature atmosphere and is a closed reaction. This is a production method in which the raw material is sprayed into a furnace to perform thermal decomposition.

Examples of the pigment dispersant for dispersing the pigment include higher fatty acid salts, alkyl sulfates, alkyl ester sulfates, alkyl sulfonates, sulfosuccinates, naphthalene sulfonates, alkyl phosphates, polyphosphates and the like. Activators such as oxyalkylene alkyl ether phosphate, polyoxyalkylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, polyoxyethylene fatty acid amide, and amine oxide, or water-soluble resins.

As a method for dispersing the pigment, various methods such as a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, and a paint shaker can be used. In the present invention, it is also preferable to use a centrifugal separator or a filter for the purpose of removing coarse particles of the pigment dispersion of the present invention.

The water-soluble resin according to the present invention will be described. As the water-soluble resin according to the present invention, a water-soluble resin having a function as a dispersant for dispersing carbon black, a pigment or the like is preferable, and among them, a styrene-acrylic acid-alkyl acrylate copolymer is preferably used. Styrene-acrylic acid copolymer, styrene-maleic acid copolymer, styrene-maleic acid-alkyl acrylate copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, Water-soluble resins such as styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer and the like.

The content of the water-soluble resin according to the present invention with respect to the total amount of the ink is preferably 0.1 to 10% by mass.
More preferably, it is 0.3 to 5% by mass.

In the ink jet recording method according to the tenth to eleventh aspects of the present invention, in order to obtain the effects according to the present invention, the content ratio of the water-soluble resin to the pigment is 1: 1: It is adjusted in the range of 1 to 15: 1, preferably in the range of 2: 1 to 10: 1.

In the ink-jet recording method according to the present invention, in order to obtain the effects described in the present invention, the average particle diameter of the pigment is preferably 100
It is preferably less than nm, more preferably 75 nm or less, particularly preferably 20 to 75 nm.

The average particle size of the pigment described above can be measured by, for example, a laser diffraction method, a laser scattering method, a dynamic laser scattering method, or the like. In the present invention, Zetasizer 1000 (manufactured by Malvern) based on the dynamic laser scattering method was used.

The solvent of the present invention will be described. As the solvent of the present invention, an aqueous liquid medium is preferably used, and as the aqueous liquid medium, a mixed solvent such as water and a water-soluble organic solvent is more preferably used. Examples of preferably used water-soluble organic solvents include alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol,
Tertiary butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol, etc., polyhydric alcohols (eg, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexane) Diol, pentanediol, glycerin, hexanetriol, thiodiglycol, etc.), polyhydric alcohol ethers (eg, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol) Monobutyl ether, professional Lene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, ethylene glycol monophenyl ether, propylene glycol monophenyl ether, etc.), amine (For example, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine , Tetramethylpro Amides (eg, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.), heterocycles (eg, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, -Oxazolidone, 1,3-dimethyl-2-imidazolidinone, etc.), sulfoxides (eg, dimethyl sulfoxide), sulfones (eg, sulfolane), urea,
Acetonitrile, acetone and the like can be mentioned.

In the present invention, a surfactant may be contained as required. Surfactants preferably used in the ink of the present invention include anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene sulfonates, and fatty acid salts, polyoxyethylene alkyl ethers, and polyoxyethylene alkyl allyl ethers. , Acetylene glycols, polyoxyethylene
Examples include nonionic surfactants such as polyoxypropylene block copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. In particular, an anionic surfactant and a nonionic surfactant can be preferably used.

The ink of the present invention may further contain a preservative, a fungicide, a viscosity modifier and the like, if necessary.

As the recording method used in the ink jet recording method of the present invention, both the on-demand method and the continuous method can be used, but the on-demand method is preferably used in that the effects of the present invention can be further improved.

As a discharge method, an electric-mechanical conversion method (for example, a single cavity type, a double cavity type, a bender type, a piston type, a shear mode type, a shared wall type, etc.) and an electric-thermal conversion method (for example, ,
Specific examples include a thermal inkjet type, a bubble jet type, etc., an electrostatic suction type (eg, an electric field control type, a slit jet type, etc.), and a discharge type (eg, a spark jet type, etc.). Either ejection method may be used.

The recording medium used in the ink jet recording method of the present invention includes, for example, plain paper, coated paper, cast coated paper, glossy paper, glossy film, OHP
Any of the films can be used. Among them, glossy paper having a gloss of 40 or more, when recording on a glossy film, image deterioration such as bleeding or beading is reduced as compared with conventionally known recording methods, and in particular, a gap type glossy paper having a gloss of 40 or more or When recording on a void type gloss film,
A remarkably excellent effect can be exhibited.

[0050]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In addition, "part" represents "part by mass".

Example 1 << Preparation of Pigment Dispersion >> (Preparation of Dispersion 1) I. Pigment Yellow 180 10 parts John Krill 62 (Johnson Polymer Co., Ltd., weight average molecular weight 8500, acid value 200, non-volatile content 34%) 5.9 parts Levenol WX (Kao Corporation) 0.3 parts Ethylene glycol 10 parts Distillation Water 30 parts System zeta LMZ-2 in which the above materials are mixed and filled with 0.3 mm zirconia beads at a volume ratio of 90%.
(Made by Ashizawa Co., Ltd.). After this, 2
Ultracentrifugation was performed at 3,000 G for 30 minutes to obtain Dispersion 1.

(Preparation of Dispersion 2) I. Pigment Yellow 128 15 parts Joncryl 61J (Johnson Polymer Co., Ltd., weight average molecular weight 12000, acid value 195, nonvolatile content 30.5%) 16.4 parts Glycerin 5 parts Distilled water 35 parts The above materials are mixed and dispersed. Dispersion and ultracentrifugation were performed in the same manner as in Example 1 to obtain Dispersion 2.

(Preparation of Dispersion 3) I. Pigment Red 122 15 parts Styrene-acrylic acid-butyl acrylate copolymer (weight average molecular weight 9500, acid value 145) 10 parts Emulgen 920 (Kao Corporation) 1 part Distilled water 35 parts The above materials are mixed and dispersed. Dispersion and ultracentrifugation were performed in the same manner as in Example 1 to obtain Dispersion 3.

(Preparation of Dispersion 4) I. Pigment Blue 15: 3 10 parts Joncryl 60 (Johnson Polymer Co., Ltd., weight average molecular weight 8500, acid value 215, nonvolatile content 34%) 8.8 parts Diethylene glycol monomethyl ether 3 parts Distilled water 45 parts The above materials were mixed, Dispersion and ultracentrifugation were performed in the same manner as in Dispersion 1 to obtain Dispersion 4.

(Preparation of Dispersion 5) I. Pigment Blue 15: 4 20 parts Joncryl 63 (Johnson Polymer Co., Ltd., weight average molecular weight 12,500, acid value 213, nonvolatile content 30%) 13.3 parts Ethylene glycol 5 parts Distilled water 50 parts The above materials are mixed and dispersed. Dispersion and ultracentrifugation were carried out in the same manner as in Dispersion 1 to obtain Dispersion 5.

(Preparation of Dispersion 6) I. Pigment Blue 15: 3 22 parts Styrene-acrylic acid-benzyl acrylate copolymer (weight average molecular weight 12000, acid value 270) 5 parts Distilled water 50 parts The above materials are mixed, and dispersed and ultracentrifuged in the same manner as in Dispersion 1. Separation treatment was performed to obtain Dispersion 6.

(Preparation of Dispersion 7) I. Pigment Yellow 128 18 parts John Krill 70 (Johnson Polymer Co., Ltd., weight average molecular weight 15000, acid value 240, non-volatile content 30%) 20 parts Distilled water 60 parts The above materials are mixed, and 0.3 mm zirconia beads are mixed by volume. System zeta LMZ-2 filled with 90%
(Dispersion 7) was obtained by using (manufactured by Ashizawa).

(Preparation of Dispersion 8) I. Pigment Yellow 180 15 parts John Krill 57 (Johnson Polymer Co., Ltd., weight average molecular weight 4900, acid value 215, nonvolatile content 37%) 2.2 parts distilled water 50 parts The above materials are mixed and dispersed in the same manner as in Dispersion 7. Was carried out to obtain a dispersion 8.

(Preparation of Dispersion 9) I. Pigment Red 122 18 parts Demol C (Kao Corporation) 4 parts Levenol WX (Kao Corporation) 0.3 parts Diethylene glycol 5 parts Distilled water 50 parts The above materials are mixed, dispersed in the same manner as in Dispersion 7, and dispersed. Obtained body 9.

<< Preparation of Ink >> (Preparation of Ink 1) Dispersion 1 160 parts Ethylene glycol 150 parts Triethylene glycol monobutyl ether 100 parts Perex OT-P (Kao Corporation) 2 parts Proxel GXL (Abisia Corporation) 2 parts Distilled water 580 parts The above materials were mixed and sufficiently stirred, and then passed twice through a Millipore filter having a pore diameter of 1 μm to obtain Ink 1. The average particle size of the pigment of the obtained ink 1 was 92 nm.

(Preparation of Ink 2) Dispersion 2 160 parts Diethylene glycol 180 parts Tripropylene glycol monomethyl ether 80 parts Orfin 1010 (Nissin Chemical Co., Ltd.) 5 parts Proxel GXL (Abisia) 2 parts Distilled water 570 parts The above-mentioned materials were stirred, mixed and filtered in the same manner as Ink 1 to obtain Ink 2. The average particle size of the pigment of the obtained ink 2 is 78 nm.
Met.

(Preparation of Ink 3) Dispersion 3 160 parts Glycerin 100 parts Tetraethylene glycol monomethyl ether 150 parts Emulgen 920 (Kao Corporation) 6 parts Proxel GXL (Abisia) 2 parts Distilled water 580 parts Was stirred, mixed and filtered in the same manner as Ink 1 to obtain Ink 3. The average particle size of the pigment of the obtained ink 3 is 38 nm.
Met.

(Preparation of Ink 4) Dispersion 4 160 parts Ethylene glycol 120 parts Dipropylene glycol monomethyl ether 120 parts Orfin 1010 (Nissin Chemical Co., Ltd.) 5 parts Proxel GXL (Abisia) 2 parts Distilled water 590 parts The above materials were stirred, mixed and filtered in the same manner as for Ink 1, to obtain Ink 4. The average particle size of the pigment of the obtained ink 4 is 45 nm.
Met.

(Preparation of Ink 5) Dispersion 5 140 parts Diethylene glycol 150 parts Triethylene glycol monobutyl ether 100 parts Adecapluronic L-62 (Asahi Denka Co., Ltd.) 4 parts Proxel GXL (Abisia) 2 parts Distilled water The above materials were stirred, mixed and filtered in the same manner as in the ink 1 to obtain an ink 5. The average particle size of the pigment of the obtained ink 5 is 68 nm.
Met.

(Preparation of Ink 6) Dispersion 6 170 parts Glycerin 110 parts Diethylene glycol monomethyl ether 120 parts Perex OT-P (Kao Corporation) 5 parts Proxel GXL (Abisia Corporation) 2 parts Distilled water 590 parts Was stirred, mixed and filtered in the same manner as Ink 1 to obtain Ink 6. The average particle size of the pigment of the obtained ink 6 is 56 nm.
Met.

(Preparation of Ink 7) Dispersion 7 180 parts Ethylene glycol 150 parts Triethylene glycol 120 parts Orfin 1010 (Nissin Chemical Co., Ltd.) 6 parts Proxel GXL (Abisia K.K.) 2 parts Distilled water 540 parts The material was stirred, mixed and filtered in the same manner as in ink 1, to obtain ink 7. The pigment average particle size of the obtained ink 7 is 148 n.
m.

(Preparation of Ink 8) Dispersion 8 160 parts Diethylene glycol 150 parts N-methyl-pyrrolidone 100 parts Emulgen 920 (Kao Corporation) 5 parts Proxel GXL (Abisia) 2 parts Distilled water 580 parts Was stirred, mixed and filtered in the same manner as Ink 1 to obtain Ink 8. The pigment average particle size of the obtained ink 8 is 165 n.
m.

(Preparation of Ink 9) Dispersion 9 160 parts Glycerin 160 parts Triethylene glycol monomethyl ether 80 parts Diacetin 10 parts Perex OT-P (Kao Corporation) 6 parts Proxel GXL (Abisia Corporation) 2 parts Distillation Water 580 parts The above materials were stirred, mixed, and filtered in the same manner as Ink 1 to obtain Ink 9. The average particle size of the pigment of the obtained ink 9 is 158 n.
m.

The following evaluations were performed on the obtained inks 1 to 9. Table 1 shows the obtained results.

The ink jet recording of the present invention was evaluated by a micro-droplet observing apparatus shown in FIGS. 1 and 2 for evaluating the bending of the micro-droplets ejected from the nozzle during flight.

FIG. 1 shows that the ink is ejected as minute droplets 6 from a piezo type inkjet head 3 having 128 nozzles, and the ejection state is composed of a strobe 4, a CCD camera 2, a monitor 1, a control PC 5 and the like. FIG. 2 is a schematic diagram showing an example in which observation is performed by a micro-droplet observation device of a strobe light emission system. The flying state of the minute liquid droplets 6 ejected from the inkjet head 3 can be observed by synchronizing the ejection of the ink and the emission of light with an observing device of a strobe light system.

FIG. 2 is a partially enlarged view of the ink-jet head, in which the flying of fine droplets discharged from the nozzles of the ink-jet head 3 is observed, and the angle θ from the perpendicular direction 11 on the nozzle plate surface 9 is observed. Is shown, and an example of a method for evaluating the bending of the nozzle is shown. That is, the deviation of the angle θ between the nozzle plate surface 9 and the perpendicular direction is observed, and the state of flight of the minute droplet after the ejection is observed.
The method of checking the bend is adopted.

(Evaluation) ・ Flying bending occurred Nozzle diameter 23 μm, driving frequency 18 kHz, droplet volume 5
pl, each of the inks is ejected from a piezo-type inkjet head having 128 nozzles per color, and the ejection state is synchronized with the ejection and emission by using a strobe emission type observation apparatus shown in FIG. , Observed. At this time, as shown in FIG. 2, the nozzles having an angle deviation of 3 degrees or more from the perpendicular direction with respect to the nozzle plate were ranked as follows with the nozzle being bent. The observation was made one minute after the start of the continuous ejection.

A: normal without any bending in all 128 nozzles B: bending with 1 to 5 nozzles C: bending with 6 to 10 nozzles D・ Bent with 11 or more nozzles ・ Satellite generation Nozzle diameter 23μm, drive frequency 18kHz, droplet volume 5
pl, 100 with an inkjet printer equipped with a piezo-type inkjet head having 128 nozzles per color (the distance between the nozzles and the recording medium is adjusted to 1 mm).
The dots were recorded. The number of satellites (dots recorded away from the main dot and smaller than the main dot) was counted and evaluated. Konica PhotoJet Paper QP (manufactured by Konica Corporation) was used as a recording medium.

A: No satellite is generated B: Less than 10 satellites C: Less than 50 satellites D: 50 or more satellites • Clogging Nozzle diameter 23μm, drive frequency 18kHz, droplet volume 5
1 liter of each ink, which had been stored for 30 days in a 60 ° environment and forcedly degraded, was continuously discharged to a piezo-type inkjet head having a pl and 128 nozzles. 1
The number of clogged nozzles after liter discharge was counted.

[0076]

[Table 1]

As is evident from Table 1, the use of the ink of the present invention improves flight bending, generation of satellites and clogging.

Example 2 << Preparation of Pigment Dispersion >> (Preparation of Dispersion 10) Toka Black # 8500 (Tokai Carbon Co., Ltd.) 12 parts Joncryl 62 (Johnson Polymer Co., Ltd., weight average molecular weight 8500, acid value) 5.9 parts Levenol WX (Kao Corporation) 0.3 parts Diethylene glycol 10 parts Distilled water 30 parts The above materials were mixed, and 0.3 mm zirconia beads were filled at a volume ratio of 90%. System zeta LMZ-2
(Made by Ashizawa Co., Ltd.). After this, 2
Ultracentrifugation was performed for 30 minutes under the condition of 000 G to obtain Dispersion 10.

(Preparation of Dispersion 11) Printex 90 (Degussa Japan Co., Ltd.) 16 parts Joncryl 61J (Johnson Polymer Co., Ltd., weight average molecular weight 12000, acid value 195, nonvolatile content 30.5%) 16.4 Part Ethylene glycol 5 parts Distilled water 35 parts The above-mentioned materials were mixed, and dispersed and subjected to ultracentrifugation in the same manner as Dispersion 10, to obtain Dispersion 11.

(Preparation of Dispersion 12) Carbon Black # 2600 (Mitsubishi Chemical Corporation) 15 parts Styrene-acrylic acid-butyl acrylate copolymer (weight average molecular weight 9500, acid value 145) 10 parts Perex OT-P (Kao Corporation) 1 part Distilled water 35 parts The above-mentioned materials were mixed, and dispersed and ultracentrifuged in the same manner as Dispersion 10, to obtain Dispersion 12.

(Preparation of Dispersion 13) Printex 80 (Degussa Japan Co., Ltd.) 20 parts Styrene-methacrylic acid-methyl methacrylate (weight average molecular weight 11500, acid value 210) 1.3 parts Diethylene glycol monomethyl ether 3 parts Distilled water 45 parts The above materials were mixed, and subjected to dispersion and ultracentrifugation in the same manner as in Dispersion 10, to obtain Dispersion 13.

(Preparation of Dispersion 14) Color Black S160 (Degussa Japan Co., Ltd.) 20 parts John Krill 63 (Johnson Polymer Co., Ltd., weight average molecular weight 12,500, acid value 213, nonvolatile content 30%) 13.3 parts Ethylene glycol 5 parts Distilled water 50 parts The above-mentioned materials were mixed and dispersed and subjected to ultracentrifugation in the same manner as Dispersion 10 to obtain Dispersion 14.

(Preparation of Dispersion 15) MA100 (Mitsubishi Chemical Corporation) 22 parts Styrene-acrylic acid-benzyl acrylate copolymer (weight average molecular weight 12000, acid value 270) 5 parts Distilled water 50 parts After mixing, dispersion and ultracentrifugation were performed in the same manner as in the case of Dispersion 10, to obtain Dispersion 15.

(Preparation of Dispersion 16) Toka Black # 7550 (Tokai Carbon Co., Ltd.) 18 parts Joncryl 70 (Johnson Polymer Co., Ltd., weight average molecular weight 15000, acid value 240, nonvolatile content 30%) 20 parts Distillation Water 60 parts The above materials were mixed and subjected to dispersion and ultracentrifugation in the same manner as Dispersion 10 to obtain Dispersion 16.

(Preparation of Dispersion 17) MA220 (Mitsubishi Chemical Corporation) 15 parts John Krill 57 (Johnson Polymer Co., Ltd., weight average molecular weight 4900, acid value 215, nonvolatile content 37%) 8.1 parts distilled water 50 parts The system zeta LMZ-2 in which the above materials were mixed and filled with zirconia beads of 0.3 mm at a volume ratio of 90%.
(Dispersion 17) was obtained by using (manufactured by Ashizawa).

(Preparation of Dispersion 18) Toka Black # 7050 (Tokai Carbon Co., Ltd.) 18 parts Demol C (Kao Corporation) 4 parts Levenol WX (Kao Corporation) 0.3 parts Diethylene glycol 5 parts Distilled water 50 parts of the above materials were mixed and dispersed in the same manner as Dispersion 17, to obtain Dispersion 18.

(Preparation of Dispersion 19) Color Black FW2 (Degussa Japan Co., Ltd.) 17 parts Joncryl 60 (Johnson Polymer Co., Ltd., weight average molecular weight 8500, acid value 215, nonvolatile content 34%) 2.9 parts Distilled water 60 parts The above materials were mixed, and dispersed in the same manner as in Dispersion Liquid 17 to obtain Dispersion Liquid 19.

<< Preparation of Ink >> (Preparation of Ink 10) Dispersion 10 160 parts Ethylene glycol 150 parts Triethylene glycol monobutyl ether 100 parts Perex OT-P (Kao Corporation) 2 parts Proxel GXL (Abisia Corporation) 2 parts Distilled water 580 parts The above materials were mixed and sufficiently stirred, and then passed twice through a Millipore filter having a pore diameter of 1 μm to obtain Ink 1. The resulting ink 10 had an average pigment particle size of 44 nm.

(Preparation of Ink 11) Dispersion 11 160 parts Diethylene glycol 180 parts Tripropylene glycol monomethyl ether 80 parts Orfin 1010 (Nissin Chemical Co., Ltd.) 5 parts Proxel GXL (Abisia) 2 parts Distilled water 570 parts The above materials were stirred, mixed and filtered in the same manner as ink 10 to obtain ink 11. The pigment average particle size of the obtained ink 11 is 3
It was 8 nm.

(Preparation of Ink 12) Dispersion 12 160 parts Glycerin 100 parts Tetraethylene glycol monomethyl ether 150 parts Emulgen 920 (Kao Corporation) 6 parts Proxel GXL (Abisia) 2 parts Distilled water 580 parts Was stirred, mixed and filtered in the same manner as ink 10 to obtain ink 12. The average particle size of the pigment of the obtained ink 12 is 5
It was 5 nm.

(Preparation of Ink 13) Dispersion 13 160 parts Ethylene glycol 120 parts Dipropylene glycol monomethyl ether 120 parts Orphin 1010 (Nissin Chemical Co., Ltd.) 5 parts Proxel GXL (Abisia) 2 parts Distilled water 590 parts The above materials were stirred, mixed and filtered in the same manner as ink 10 to obtain ink 13. The average particle size of the pigment of the obtained ink 13 is 6
It was 0 nm.

(Preparation of Ink 14) Dispersion 14 140 parts Diethylene glycol 150 parts Triethylene glycol monobutyl ether 100 parts Adecapluronic L-62 (Asahi Denka Co., Ltd.) 4 parts Proxel GXL (Abisia) 2 parts Distilled water The above-mentioned materials were stirred, mixed and filtered in the same manner as in the ink 10 to obtain an ink 14. The pigment average particle size of the obtained ink 14 is 4
It was 8 nm.

(Preparation of Ink 15) Dispersion 15 170 parts Glycerin 110 parts Diethylene glycol monomethyl ether 120 parts Perex OT-P (Kao Corporation) 5 parts Proxel GXL (Abisia Corporation) 2 parts Distilled water 590 parts Was stirred, mixed and filtered in the same manner as ink 10 to obtain ink 15. The pigment average particle diameter of the obtained ink 15 is 8
It was 0 nm.

(Preparation of Ink 16) Dispersion 16 180 parts Ethylene glycol 150 parts Triethylene glycol 120 parts Olfin 1010 (Nissin Chemical Co., Ltd.) 6 parts Proxel GXL (Abisia Co., Ltd.) 2 parts Distilled water 540 parts The material was stirred, mixed and filtered in the same manner as for ink 10, to obtain ink 16. The average particle size of the pigment of the obtained ink 16 is 7
It was 8 nm.

(Preparation of Ink 17) Dispersion 17 160 parts Diethylene glycol 150 parts N-methyl-pyrrolidone 100 parts Emulgen 920 (Kao Corporation) 5 parts Proxel GXL (Abisia) 2 parts Distilled water 580 parts Was stirred, mixed and filtered in the same manner as ink 10 to obtain ink 17. The average particle size of the pigment of the obtained ink 17 is 1
It was 10 nm.

(Preparation of Ink 18) Dispersion 18 160 parts Glycerin 160 parts Triethylene glycol monomethyl ether 80 parts Diacetin 10 parts Perex OT-P (Kao Corporation) 6 parts Proxel GXL (Abisia Corporation) 2 parts Distillation Water 580 parts The above materials were stirred, mixed and filtered in the same manner as ink 10 to obtain ink 18. The pigment average particle diameter of the obtained ink 18 is 1
It was 15 nm.

(Preparation of Ink 19) Dispersion 19 180 parts Ethylene glycol 130 parts Diethylene glycol monoethyl ether 120 parts Orphin 1010 (Nissin Chemical Co., Ltd.) 10 parts Proxel GXL (Abisia) 2 parts Distilled water 560 parts The above-mentioned materials were stirred, mixed and filtered in the same manner as the ink 10 to obtain an ink 19. The pigment average particle diameter of the obtained ink 19 is 1
20 nm.

The obtained inks 10 to 19 were evaluated as follows. Table 2 shows the obtained results.

[0099] The generation of flying bending nozzle diameter 20 μm, driving frequency 30 kHz, droplet volume 4
pl, each ink is ejected from a piezo-type inkjet head having 128 nozzles per color, and the ejection state is observed by synchronizing the ejection and emission with a strobe emission type observation apparatus shown in FIG. did. At this time, as shown in FIG. 2, the nozzles having an angle deviation of 3 degrees or more from the perpendicular direction with respect to the nozzle plate were ranked as follows with the nozzle being bent. The observation was made one minute after the start of the continuous ejection.

A: normal without any bending in all 128 nozzles B: bent with 1 to 5 nozzles C: bent with 6 to 10 nozzles D:・ Bent with 11 or more nozzles ・ Satellite generation Nozzle diameter 20 μm, drive frequency 30 kHz, droplet volume 4
pl, an inkjet printer equipped with a piezo type inkjet head having 128 nozzles per color (the distance between the nozzles and the recording medium is adjusted to 1 mm).
The dots were recorded. The number of satellites (dots smaller than the main dot recorded away from the main dot) was counted and evaluated. Konica PhotoJet Paper QP (manufactured by Konica Corporation) was used as a recording medium.

A: No satellite is generated B: Less than 10 satellites C: Less than 50 satellites D: 50 or more satellites: Clogging Nozzle diameter 20 μm, drive frequency 30 kHz, droplet volume 4
1 liter of each ink, which had been stored for 30 days in a 60 ° environment and forcedly degraded, was continuously discharged to a piezo-type inkjet head having a pl and 128 nozzles. 1
The number of clogged nozzles after liter discharge was counted.

[0102]

[Table 2]

As is evident from Table 2, the use of the ink of the present invention improves flight bending, generation of satellite and clogging.

[0104]

According to the present invention, it is possible to provide an ink-jet recording method in which the ink-jet head nozzle is less clogged and the recording dots are close to a perfect circle in the super-drop method.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a basic configuration around an ink jet head of an ink jet recording apparatus which is an embodiment of an ink jet recording method of the present invention.

FIG. 2 shows a partially enlarged view of the ink jet head.

[Description of Signs] 1 monitor 2 CCD camera 3 inkjet head 4 strobe 5 control PC 6 microdroplet 6a microdroplet 6b microdroplet 7 nozzle 8 nozzle 9 nozzle plate surface 10 flight angle θ 11 perpendicular from nozzle plate surface

Claims (16)

[Claims] An ink containing carbon black having a volatile component of not more than 15% by mass and a nitrogen adsorption specific surface area of not less than 100 m ³ / g, a dispersant and a solvent is obtained by a head driven at a driving frequency of 15 kHz or more. An ink jet recording method, wherein recording is performed by discharging. 2. The ink jet recording method according to claim 1, wherein the nitrogen adsorption specific surface area of the carbon black is 150 m ³ / g or more. 3. The ink jet recording method according to claim 1, wherein the carbon black has a nitrogen adsorption specific surface area of 200 m ³ / g or more. 4. A head driven at a driving frequency of 15 kHz or more, wherein a volatile component is 15% by mass or less and DB
Ink jet recording method and performing recording by P oil absorption of ejecting an ink containing 70cm ^3/100 g or more of the carbon black, dispersing agent and a solvent. 5. The ink jet recording method according to claim 4 wherein the DBP oil absorption of the carbon black is 80 cm ^3/100 g or more. 6. A head driven at a drive frequency of 15 kHz or more discharges an ink containing carbon black having a volatile component of 15% by mass or less and a primary particle size of 30 nm or less, a dispersant, and a solvent. An ink jet recording method comprising performing recording. 7. The carbon black has a primary particle size of 20.
7. The ink jet recording method according to claim 6, wherein the diameter is not more than nm. 8. The carbon black having a primary particle size of 5 to 5.
The ink jet recording method according to claim 6, wherein the thickness is 15 nm or less. 9. The ink jet recording method according to claim 1, wherein the volatile component is 8% by mass or less. 10. A head driven at a driving frequency of 15 kHz or more, containing a water-soluble resin, a pigment and a solvent, and wherein the content ratio of the pigment to the water-soluble resin is 1: 1 to 1 by mass.
15. An ink jet recording method, wherein recording is performed by discharging ink at a ratio of 15: 1. 11. The ink jet recording method according to claim 10, wherein the content ratio of the pigment and the water-soluble resin in the ink is 2: 1 to 10: 1 by mass. 12. Recording is performed by discharging ink containing a dispersant, a pigment, and a solvent and having an average particle diameter of the pigment of less than 100 nm by a head driven at a driving frequency of 15 kHz or more. Inkjet recording method. 13. The ink according to claim 13, wherein the pigment has an average particle size of 75 n.
The inkjet recording method according to claim 12, wherein m is equal to or less than m. 14. The ink according to claim 14, wherein the pigment has an average particle size of 20 to
The ink jet recording method according to claim 12, wherein the thickness is 75 nm. 15. The recording is performed by a head driven at a driving frequency of 20 kHz or more.
The inkjet recording method according to any one of claims 1 to 4. 16. The ink jet recording method according to claim 1, wherein the recording method is an on-demand method.