JPH08333536A - Aqueous ink, ink jet recording using the same and apparatus using the same ink - Google Patents

Abstract

PURPOSE: To obtain an aqueous ink for ink jetting, containing a polymer showing heat sensitively thickening properties obtained by copolymerizing a specific monomer composition, free from feathering and bleeding problems despite acquisition of high optical concentration. CONSTITUTION: This aqueous ink consists of a liquid composition containing coloring material(s) (pref. carbon black and/or an organic pigment) and contains a heat sensitively thickening polymer (pref. a vinyl polymer 2,000-500,000 in molecular weight and 10-80 deg.C in the transition temperature presenting a heat- sensitive thickening) obtained by copolymerization of a monomer composition containing a total of >=50wt.% of (A) at least one kind of monomer of a water- soluble polymer having cloud point and (B) at least one kind of monomer of the formula [R1 is H or CH3 ; R2 is H, a 1-30C alkyl, (alkyl)phenyl or (alkyl- substituted) aminoalkyl; (n), (m) and (l) are each 2-4; (x) is 0-20; (y) and (z) are each 0-50]. Besides, it is preferable that this aqueous ink contain each 0.01-5wt.% of fine particle dispersion and a basic or cationic compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ink jet recording in which an aqueous writing instrument and ink are ejected and ejected as small droplets from an ejection port (orifice), and the small droplets are adhered to the surface of a recording material for recording. A water-based ink to be used, an ink jet recording method using the same, and a device using such an ink, in particular, bleeding (feathering) and color-mixing bleeding are eliminated, and water resistance of a printed matter is improved. The present invention relates to a water-based ink that realizes color development, an inkjet recording method using the same, and a device using such an ink.

[0002]

2. Description of the Related Art Conventionally, water-based inks have been mainly used for writing instruments and the like in terms of safety and odor, and various water-soluble organic solvents,
It is composed of a water-soluble dye or pigment. Further, as the ink jet recording ink, water-based ink is mainly used from the viewpoints of dischargeability, safety, odor, etc., and various water-soluble dyes or pigments are dissolved or dispersed in water or water and a water-soluble organic solvent, There is known an ink containing a moisturizer, a dye dissolution aid, a fungicide, etc., if necessary. Inkjet recording using these inks is capable of ejecting several thousand drops or more of ink per second, easy high-speed recording, low noise, easy colorization, and high resolution. It has many advantages such as the ability to record on paper and has been popular for several years.

Furthermore, in recent years, the price and performance of personal computers have increased,
By standardizing the GUI environment, image recording by printers, etc.
The demand for high color development, high quality, high robustness, high resolution recording and high speed recording has increased, leaving the color material components in the ink used on the surface of the paper as much as possible to make the edges of the recording dots clear.
A technical idea is being proposed to reduce blurring (feathering) and color mixture blurring (bleeding) of an image to be formed.

As a first example thereof, Japanese Patent Laid-Open No. 58-136.
No. 75, a method of adding polyvinylpyrrolidone to an ink to control the absorption and spread of recording dots on paper, and a second example, Japanese Patent Laid-Open No. 3-172362, discloses a specific microemulsion. Is added to the ink to control ink absorption and dot spread.

Further, as a third example in which the sol-gel transition phenomenon is applied to an ink, there are inks described in JP-A-62-181372 and JP-A-1-272673, and the ink has a room temperature. It is said that the gel state and the sol state by heating are recorded on the recording material in the sol state, and the ink returns to the gel state by cooling the ink, so that the permeation of the ink into the paper can be suppressed.

Also, as a fourth example recently, Japanese Unexamined Patent Publication No. 6-493.
No. 99, an ink having a compound having a reversible thermal gelation property is added to the ink to have good colorability, fixability, less bleeding, excellent storage stability of printed matter, and excellent reliability. Ink jet recording methods and devices using ink are disclosed. This technical background is based on the phenomenon that when an aqueous solution of a specific water-soluble polymer is heated, the water solubility decreases and the solution becomes cloudy (this temperature is called a cloud point). Representative examples of these polymers are poly N-isopropyl acrylamide, polyvinyl methyl ether, polyethylene oxide and hydroxypropyl cellulose.

Since the solubility of these polymers has a negative temperature coefficient, they become separated and precipitated from the solution above the cloud point. In the deposited state, a hydrophobic microgel is generated and the viscosity of the solution is reduced. When recording is performed on the recording material in the deposited state, the original viscosity is restored due to the temperature drop on the surface of the recording material; that is, the viscosity is increased and ink penetration can be suppressed.

On the other hand, as a fifth example, Japanese Patent Laid-Open No. 3-240
Japanese Patent No. 586 proposes a non-aqueous ink in which colored particles coated with a resin that swells in a dispersion medium are dispersed in kerosene or the like. This proposal states that it is particularly effective in preventing image bleeding and preventing clogging of droplet discharge nozzles.

[0009]

In the first and second conventional examples described above, in order to suppress the permeation of the ink into the paper, the ink remains for a long time without penetrating on the paper, There is a problem with the fixability of. Further, when forming a color image, there is a problem that color mixing (bleeding) between different colors occurs. The sol-gel transition ink of the third example may have fluidity due to changes in the storage temperature of the printed matter, and there is a problem of color mixing stains and transfer stains of the image due to the ink flowing out.

In the ink containing the reversible thermogelling compound of the fourth example, since water-soluble cellulose ethers are used,
The increase in viscosity due to the temperature decrease is slow, and it is not suitable for a method of recording one pixel at a high speed of several tens of msec or less like inkjet recording. Moreover, when this ink is used for ink jet recording, the upper limit of the viscosity at the time of ink ejection is 20 mP.
Since it is as low as as or less, it must be used at a low concentration,
It is difficult to obtain a sufficient thickening effect. Further, the water resistance of the printed matter cannot be obtained because it is a water-soluble polymer.

Further, in the fifth conventional example, since kerosene is used as the dispersion medium, there are problems such as odor and safety. The physical properties required for ejecting small droplets as an aqueous ink, particularly an inkjet ink, are surface tension:> 20 dyne / cm (related to refill speed), viscosity: 1 to 20 mPa ·
s, pH: 3 to 10 and the fixing time is <20 sec (the shorter the better). Since the coloring of the recording material depends on the penetration and evaporation of the ink, The ejected ink cannot control changes in its physical properties.

Further, in a water-soluble polymer having a cloud point such as a polymer of N-isopropylacrylamide, when a large amount of an electrolyte (salt) such as NaCl coexists, a carbonyl group (C═O) serving as a base point of hydrogen bond. Since the oxygen in (1) is preferentially bound to sodium ions, the thermoreversible change in the dissolved state (phase separation at the cloud point or higher and the liquid viscosity decreases) will not occur. This is because, for example, a dye molecule which is a sodium salt coexists like ink, so that thermoreversible behavior is not exhibited, and it is meaningless to add the polymer to the ink.

Therefore, an object of the present invention is to use a water-based ink which, in addition to high image quality, solves the problems of image bleeding (feathering), color bleeding (bleeding) and water resistance and realizes high color development. An object of the present invention is to provide an inkjet recording method and a device using such an ink.

[0014]

The above object can be achieved by the present invention described below. That is, the present invention is represented by the following general formula (I) in an ink composed of a liquid composition containing a coloring material and a liquid medium, and one or more kinds of water-soluble polymer monomers exhibiting a cloud point. A polymer (A) having a thermosensitive thickening property (thermoreversible thickening property) obtained by copolymerizing a monomer composition containing at least 50% by weight of one or more monomers in total. A water-based ink containing the same, an inkjet recording method using the same, and a device using the ink.

[0015] (However, in the general formula (I), R ₁ is H or C
H ₃ and R ₂ represent H, an alkyl group having 1 to 30 carbon atoms, a (alkyl) phenyl group or an (alkyl-substituted) aminoalkyl group, n is 2 to 4, m is 2 to 4 and l is 2 to 4 , X is 2
˜50, y is an integer of 0 to 50, and z is an integer of 0 to 50, excluding those in which n, m and l have the same number, and those in which n and m or m and l have the same number. . )

[0016]

According to the present invention, the limitation of the prior art is that the ink is a liquid in which the coloring material and the solvent are in a uniform state regardless of the temperature. We devised an ink that behaves by separating the coloring material and the solvent on the recording material. That is, the state change means that, in the ink state at room temperature, the dissolved and dissociated polymer molecules associate with each other when the temperature rises above a certain temperature to form a thick high-viscosity liquid, and By forming a state in which the material is bonded to the polymer and recording on the recording material in that state, a rich color material phase remains on the surface of the recording material to form an image.

Further, the above-mentioned change is required to be reversible in order to correspond to a wide range of environmental temperature at the time of recording. In practice, low viscosity is more advantageous for high-speed recording when ejecting small liquid droplets from the recording head. Therefore, recording is performed when the droplets are ejected with a low viscosity during operation and heated above the transition temperature. The above phenomenon is realized by recording on the material. In the present invention, the cloud point is defined as the temperature at which the aqueous polymer solution becomes cloudy, and the transition temperature is defined as the temperature at which the dissolved state of the aqueous polymer solution changes (clouding is not essential).

Under the above conditions, since the temperature of the ink droplet is less than the temperature of the recording material, the surface of the recording material is cooled at the moment when the ink droplet adheres to the surface of the recording material, and the ink droplet has a transition temperature. There is a slight delay in rising to. In order to keep the viscosity low until the viscosity rises, Lucas-Washburn
The ink permeates the recording material according to the equation. This is also a means for eliminating the problem of scratching as a recorded image if all the coloring material is left on the surface of the recording material.

In a stationary recording apparatus such as an ink jet recording apparatus, the transition temperature is higher than the ambient temperature (room temperature) normally used, and the thickening by the temperature becomes effective (the temperature difference before and after the state change). 10 ° C. or higher and 85 ° C. or lower is desirable in order to increase If the temperature exceeds 85 ° C., the viscosity of the water in the ink evaporates significantly, which is not preferable. Further, when applied to this water-based pen, it is necessary for such a device to have a transition temperature lower than the body temperature of the human body, because the heat source depends on heat transfer from the finger holding the pen. Therefore, a transition temperature of 10 ° C. or higher is suitable for exhibiting a sufficient thermosensitive viscosity increase.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. First, the heat-sensitive thickening polymer (A) used in the ink of the present invention will be described. The thermosensitive thickening polymer is a polymer whose aqueous solution, water suspension or the like thickens at a certain temperature (transition temperature) or more and has a reversible temperature-viscosity relationship.

The polymer (A) used in the present invention is one or more kinds of water-soluble polymer monomers having a cloud point and one or more kinds of monomers represented by the following general formula (I). And a total of 50
It is obtained by copolymerizing a monomer composition containing at least wt%.

[0022] (However, in the general formula (I), R ₁ is H or C
H ₃ and R ₂ represent H, an alkyl group having 1 to 30 carbon atoms, a (alkyl) phenyl group or an (alkyl-substituted) aminoalkyl group, n is 2 to 4, m is 2 to 4 and l is 2 to 4 , X is 2
˜50, y represents an integer of 0 to 50, and z represents an integer of 0 to 50, and n and m and l are the same number, and n and m or m and l are the same number. except. )

A water-soluble polymer monomer having a cloud point is a compound having both a hydrophilic portion and a hydrophobic portion in its molecule, and an N-alkyl-substituted vinyl monomer is a typical example. Is. Specifically, for example, N-ethylacrylamide, N-cyclopropyl (meth) acrylamide, N-
Isopropyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-tetrahydrofuryl acrylamide,

N-acryloylpyrrolidine, N-acryloylpiperidine, N-2-ethoxyethyl (meth) acrylamide, N-3-methoxypropyl (meth) acrylamide, N-3-ethoxypropyl (meth) acrylamide, N-3- Isopropoxypropyl (meth) acrylamide, N-3- (2-methoxyethoxy) propyl (meth) acrylamide, N-1-methyl-2-methoxyethyl (meth) acrylamide, N-1-methoxymethylpropyl (meth) acrylamide , N-methyl-N-ethylacrylamide,

N-methyl-N-isopropylacrylamide, N-methyl-Nn-propylacrylamide,
N, N-diethylacrylamide, N- (2,2-dimethoxyethyl) -N-methylacrylamide, N-
(1,3-Dioxolan-2-ylmethyl) -N-methylacrylamide, N- (8-acryloyl-1,4-
Dioxa-8-azaspiro [4,5] decane, N-2-
Methoxyethyl-N-ethylacrylamide,

N-2-methoxyethyl-Nn-propylacrylamide, N-2-methoxyethyl-N-isopropylacrylamide, N, N-bis (2-methoxyethyl) acrylamide, methyl vinyl ether, 2-
(2-methoxyethyl) ethyl vinyl ether, 2-methyl-5-vinyl pyridine, N-vinyl pyrrolidone, ethylene oxide and the like can be mentioned.

As the function of the monomer represented by the general formula (I), since the linear molecule has a large number of ether oxygens, even if a salt coexists, the positively charged portion of the salt is ether oxygen. Since it is preferentially coordinated to the polymer, it does not affect the change in the state of the polymer exhibiting heat-sensitive thickening used in the present invention.
That is, by copolymerizing the monomer represented by the general formula (I) with a monomer having a thermosensitive viscosity increase, the salt resistance of the polymer can be dramatically improved.

Examples of the above-mentioned monomer (I) include, for example,
It has a structure in which an alkylene oxide is added to a vinyl (meth) acrylic acid monomer, and for example, (1) ω-
Methoxy polyethylene glycol monoacrylate,
(2) ω-methoxy polyethylene glycol monomethacrylate, (3) ω-ethoxy polyethylene glycol monoacrylate,

(4) ω-ethoxy polyethylene glycol monomethacrylate, (5) ω-n-propyl polyethylene glycol monoacrylate, (6) ω-n-propyl polyethylene glycol monomethacrylate,
(7) ω-iso-propyl polyethylene glycol monoacrylate, (8) ω-iso-propyl polyethylene glycol monomethacrylate, (9) ω-n-butyl polyethylene glycol monoacrylate, (1
0) ω-n-butyl polyethylene glycol monomethacrylate, (11) ω-iso-butyl polyethylene glycol monoacrylate,

(12) ω-iso-butyl polyethylene glycol monomethacrylate, (13) ω-tert
-Butyl polyethylene glycol monoacrylate,
(14) ω-tert-butyl polyethylene glycol monomethacrylate, (15) ω-phenoxy polyethylene glycol monoacrylate, (16) ω-phenoxy polyethylene glycol monomethacrylate, (1
7) (poly) propylene glycol-polyethylene glycol monoacrylate, (18) (poly) propylene glycol-polyethylene glycol monomethacrylate,

(19) ω-methoxy (poly) propylene glycol-polyethylene glycol monoacrylate, (20) ω-methoxy (poly) propylene glycol-polyethylene glycol monomethacrylate, (2
1) (poly) butylene glycol-polyethylene glycol monoacrylate, (22) (poly) butylene glycol-polyethylene glycol monomethacrylate,

(23) ω-methoxy (poly) butylene glycol-polyethylene glycol monoacrylate,
(24) ω-methoxy (poly) butylene glycol-polyethylene glycol monomethacrylate, (25) ω
-Methoxy (poly) ethylene glycol- (poly) propylene glycol-polyethylene glycol monoacrylate,

(26) ω-methoxy (poly) ethylene glycol- (poly) propylene glycol-polyethylene glycol monomethacrylate, (27) ω-hexyloxypolyethylene glycol mono (meth) acrylate, (28) octadecyloxypolyethylene glycol mono ( (Meth) acrylate, (29) ω-octylphenyl (poly) ethylene glycol-polypropylene glycol mono (meth) acrylate,

(30) Nonylphenyloxy (poly) ethylene glycol- (poly) propylene glycol-polyethylene glycol mono (meth) acrylate, (3
1) polypropylene glycol mono (meth) acrylate, (32) ω-methoxypolybutylene glycol rumono (meth) acrylate, (33) ω-methoxypolytetramethylene glycol rumono (meth) acrylate,
(34) ω-dimethylaminoethyl polyethylene glycol rumono (meth) acrylate and the like.

As a method for synthesizing the above-mentioned monomer, for example,
(1) In the presence of an alkali metal catalyst (sodium hydroxide, potassium hydroxide, etc.) on methacrylic acid or acrylic acid, 5
A method of sequentially adding alkylene oxides (ethylene oxide, propylene oxide and / or butylene oxide) at 0 to 200 ° C. and 1 to 10 atmospheres, (2) carbon number of 1 to 4
Polyether monool and methacrylic acid obtained by sequentially adding alkylene oxide (ethylene oxide, propylene oxide and / or butylene oxide) to the alcohol or phenol of 50 to 200 ° C. at 1 to 10 atmospheres in the presence of an alkali metal catalyst or Acrylic acid in the presence of an acidic catalyst (sulfuric acid, paratoluene sulfonic acid, etc.) 50
Examples of the method include esterification at ˜200 ° C. and 1 to 10 atm, or reaction with an esterification reagent (zinc hexylcarbodiimide, etc.) at −10 to 50 ° C. and normal pressure.

Next, the ink of the present invention may further contain a basic or cationic compound in addition to the above constitution. Such a compound is a molecule having an amide group, an amino group, an imino group, a quaternary ammonium base and / or an amine base, and since it is basic or cationic, it has a coloring material skeleton like a direct dye. It has a hydrogen-bonding group and can bond with anionic molecules, thus reducing the solubility of the dye. As a result, the effect of further enhancing the water resistance of the recorded matter can be obtained.

Examples of the basic or cationic compound include, for example, primary amine hydrochloride (R-NH ₂ .HC
1), secondary amine hydrochloride such as R (R ₁ ) NH.HCl, tertiary amine hydrochloride such as R (R ₁ ) (R ₂ ) N.HCl, lauryl dimethylbenzyl ammonium salt Benzalkonium salt, benzyldimethyl {2- [2-
Aliphatic quaternary ammonium salts such as benzethonium chloride such as (p-1,1,3,3-tetramethylbutylphenoxy) ethoxy] ethyl} ammonium chlorido, alkylpyridinium salts, imidazolinium salts, and Amphoteric surfactants that show cationicity on the acidic side; carboxybetaines such as lauryldimethylbetaine, aminocarboxylic acid salts such as laurylaminopropylglycine, 2-lauryl-N-carboxymethyl-N-hydroxylethylimidazolinium betaine. Such as imidazolinium betaine, lecithin, and cationized starch, polyallylamine, polyvinyl imidazoline salt, poly-N, N-dimethylaminoethyl (meth) acrylamide, poly-N,
N-dimethylaminopropyl (meth) acrylamide,
Polyvinyl pyridine, polyvinyl imidazole, dicyandiamide / formalin polycondensate, dicyanamide / diethylenetriamine polycondensate, epichlorohydrin / dimethylamine addition polymer, dimethylallylammonium chloride, dialkylaminoethyl (meth) acrylate quaternary salt polymer, etc. I can.

Among the above compounds, vinyl monomers such as N, N-dimethylaminoethyl (meth) acrylate are water-soluble polymer monomers having a cloud point used in the present invention. Sufficient effects can be obtained by copolymerizing one or more species with one or more of the monomers represented by the general formula (I) and using them as a constituent of the thermosensitive thickening polymer (A) obtained. .

The basic or cationic compound as described above must be selected in an appropriate amount with respect to the amount of the coloring material added such as a dye used at the same time, but preferably 0.01 to 5.
It is 0% by weight, more preferably 0.01 to 2.0% by weight. In addition, since the temperature range for thickening changes depending on the composition ratio of N-alkyl-substituted acrylamides having a cloud point among the monomers constituting the polymer (A) used in the present invention, the temperature range is In order to make it as small as possible, N- which shows the cloud point
The content of the monomer such as alkyl-substituted acrylamide is preferably 50% by weight or more, more preferably 70% by weight or more.

When the above-mentioned polymer is used as an aqueous solution, the viscosity decreases as the temperature rises up to a certain transition temperature,
Above the transition temperature, the viscosity increases with a high odor. Furthermore,
There is a characteristic that the temperature-viscosity relationship has almost no hysteresis. As described above, the cloud point can be easily adjusted to an arbitrary temperature by changing the type of the N-substituted alkyl group. Therefore, various recording heads whose temperature rise characteristics vary depending on the form or recording method, Alternatively, it can be applied to a writing instrument. However, the transition temperature depends on the salt in the ink, the surfactant,
Since it changes depending on the type and amount of the additive component such as the solvent, it is necessary to use the transition temperature in the ink composition to be applied.

An example of the temperature / viscosity relationship of the 5% by weight aqueous solution of the polymer is shown in FIG. The polymer used was 90 parts of N-isopropylmethacrylamide and a monomer (I
I) 10 parts and 2,2′-azobis (2,4-dimethylvaleronitrile) 0.1 parts were added to an ampoule, freeze-deaerated, sealed, and polymerized at 60 ° C. for 8 hours. is there. In the figure, the solid line shows the case where the temperature of the aqueous solution was raised at 1 ° C./min, the dotted line shows the case where the temperature was lowered at 1 ° C./min, and the transition temperature was 45 ° C.

In the present invention, the molecular weight and the addition amount of the polymer added to the ink are within the permissible range of the ink viscosity (20 mPa · s or less) for the ink jet recording ink.
The weight average molecular weight is preferably in the range of 2,000 or more and 500,000 or less. Here, if the molecular weight exceeds 500,000, the molecular chain becomes too long, the redissolution rate decreases, and spinnability is exhibited, which is not preferable. Molecular weight 2,000
In the case of around 0, the thickening effect is weak, so it is necessary to increase the addition amount, and the addition amount is preferably 2 to 10% by weight. Also, when the molecular weight is around 500,000, a small amount of addition shows a sufficient thickening effect, and the preferable addition amount is 0.005.
~ 3% by weight. Further, the effects of the present invention can be sufficiently obtained even if polymers having different molecular weights are mixed and used.

Further, the ink of the present invention can obtain sufficient recording characteristics if it contains the heat-sensitive thickening polymer, but in order to further increase the thickening effect at the transition temperature or higher, the ink is hydrophobic. It has been found that the inclusion of the fine particle dispersion can further increase the thickening effect. That is, above the transition temperature, the hydratability of the polymer exhibiting a heat-sensitive thickening decreases, and the polymer becomes hydrophobic. In this state, when a hydrophobic (polymer) fine particle dispersion such as an acrylic emulsion coexists, the affinity between the polymer and the hydrophobicity exceeds the affinity of the polymer with water, so the polymer is dispersed in the solution. It is considered that the entire system is thickened as compared with the case where only the polymer is used, by incorporating the associated fine particles and causing the association.

The increase rate of the thickening effect due to the coexistence of fine particles is
It depends on the type of fine particles used, the amount added, the type of dispersant, and the amount thereof, but in the experiments conducted by the present inventors,
A rise of 0% was seen. The fine particles that can be used for the above purpose include acrylic emulsions, styrene-acrylic emulsions, styrene-divinylbenzene emulsions, urethane emulsions, silicone-acrylic emulsions, etc., with a solid content of 8 to 40% by weight.
It is advisable to add 0.01 to 10% by weight to the ink of a particle size of 10 to 80 nm and a pH of 6.0 to 8.5.

The polymer should have high heat resistance and high hardness, and the higher the degree of crosslinking, the more suitable it is for ink jet applications. Particularly in the method of recording by applying thermal energy to the ink, it is desirable that the temperature is equal to or higher than the critical temperature of water which is the main ink solvent, and specifically,
A polymer having a 10% weight reduction temperature Tb of 300 ° C. or higher is preferable. Among the above emulsions, a styrene-divinylbenzene type (Tb: 380 ° C.) having a high degree of crosslinking is particularly preferable.

Next, the coloring material used in the ink of the present invention will be described. First, usable dyes may be those which interact with the polymer showing a thermosensitive thickening used in the present invention and promote the association of polymer chains at a transition temperature or higher. Examples thereof include dyes, food dyes, basic dyes and reactive dyes. These dyes are most hydrophobic dye skeleton and several sulfonate (-SO ₃ M), carboxylates (-COOM), ammonium salts (-NH ₃ X)
Etc. and a hydrogen bonding hydroxyl group (—OH), an amino group (—NH ₂ ), an imino group (—NH—) and the like, and can form a complex with the polymer used in the present invention. I can. The disperse dye itself is water-insoluble, but since the disperse dye is used in combination with a polycyclic anion activator such as naphthalene sulfonate as a dispersant, the apparent ionicity of the dye is the same as that of the direct dye. It can be used like a dye.

Specific examples of the dye include C.I. I. Direc
t Black 17, C.I. i. Direct Bla
ck 19, C.I. I. Direct Black 6
2, C.I. I. Direct Black 154, C.I.
I. Food Black 2, C.I. I. Reacti
ve Black 5, C.I. I. Acid Black
52, I.D. C. I. Projet Fast Bla
black dye such as ck 2,

C. I. Direct Yellow 1
1, C.I. I. Direct Yellow 44, C.I.
I. Direct Yellow 86, C.I. I. Di
rect Yellow 142, C.I. I. Direc
t Yellow 330, C.I. I. Acid Yel
low 3, C.I. I. Acid Yellow 38,
C. I. Basic Yellow 11, C.I. I. B
asic Yellow 51, C.I. I. Disper
se Yellow 3, C.I. I. Disperse
Yellow 5, C.I. I. Reactive Yel
yellow dye such as low 2

C. I. Direct Red 227,
C. I. Direct Red 23, C.I. I. Aci
d Red 18, C.I. I. Acid Red 52,
C. I. Basic Red 14, C.I. I. Basi
c Red 39, C.I. I. Disperse Red
Magenta dye such as 60,

C. I. Direct Blue 15,
C. I. Direct Blue 199, C.I. I. D
direct Blue 168, C.I. I. Acid B
lue 9, C.I. I. Acid Blue 40, C.I.
I. Basic Blue 41, C.I. I. Acid
Blue 74, C.I. I. Reactive Blu
e 15, C.I. I. Cyan dyes such as Disperse Blue 3 can be mentioned.

Other than these dyes, it is possible to use those having reduced water-solubilizing groups to enhance water resistance, special grades having pH-sensitive solubility, and the like. The concentration of the dye in the ink can be freely selected within the range of solubility, and is usually 1 to 8% by weight, preferably 3 to 10% by weight for recording on cloth, metal (alumite), etc.
Furthermore, 0.1 to 10% by weight is required when the density of the recorded image is required.
Is preferred.

Carbon black and organic pigments can be used as the second coloring material. Since these colorants use a dispersant together with the disperse dye, they can interact with the polymer compound used in the present invention through the dispersant. Such pigments can be used as long as they are suitable for ink jet recording. Among them, carbon black used for black ink is manufactured by a furnace method or a channel method and has a primary particle diameter of 10 ~ 4
0 mμ, specific surface area by BET method is 50 to 300 m ² /
g, DBP oil absorption of 40 to 150 ml / 100 g is desirable.

Specific examples of carbon black include, for example, No. 1 manufactured by Mitsubishi Kasei. 2300, No. 900, MC
F88, No. 33, NO. 40, No. 45, No.
52, MA7, MA8, # 2200B, Raven 1255, Raven 1060 manufactured by Colombia Carbon Co.,
Reba1330R, Rega166 manufactured by Cabot Corporation
0R, Mogul L, Colo from DEGUSSA
r Black FW18, Printex 35, P
rintex U and the like.

In addition, carbon black whose surface is subjected to oxidation treatment, plasma treatment, insoluble azo pigment,
Organic pigments such as soluble azo pigments, phthalocyanine-based pigments, isoindolinone-based higher pigments, quinacridone-based higher pigments, dioxazine violet, and perinone / perylene-based higher pigments can also be used. Further, as a coloring material classified into the above pigments, a so-called dyed lake in which a dye is dyed with an extender pigment; that is, food red No. 40 aluminum lake, food red No. 3 aluminum lake, food red No. 4 aluminum lake, food yellow No. 5 aluminum rake,
Edible Blue No. 2 aluminum lake can also be used as the coloring material of the present invention.

In order to impart more ink jet suitability to the ink of the present invention having the above-mentioned constitution, such as reliability, storage stability, and control of ink permeability, the following moisturizers and dissolution agents are used. You may include an auxiliary agent. Examples of such a material include 1,2-ethanediol, 1,2
-Propanediol, 1,3-propanediol, 1,
2-butanediol, 1,3-butanediol, 1,4
-Butanediol, 2,3-butanediol, 1,5-
Pentanediol, 1,7-heptanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3
-Alkylene glycols such as hexanediol, glycerin, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol 200, dipropylene glycol, 2,2'-thiodiethanol, 1,2,6-hexanetriol,

Alcohol amines such as monoethanolamine, diethanolamine and triethanolamine, aprotic polar solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, sulfolane and 1,3-propanesultone,

1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-dibutoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, 2-methoxyethanol, 2-ethoxyethanol, 2- ( (Methoxymethoxy) ethanol, 2-butoxyethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ethyl ether, 1-methoxy-2-
Lower alkyl ethers of polyhydric alcohols such as propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether,

Formamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, sorbitol, sorbit, urea, 1,3-bis (β-hydroxyethyl) urea and the like can be mentioned. The content in these inks is preferably in the range of 1 to 40% by weight based on the total weight of the ink.

Further, when the ink of the present invention is used for ink jet recording, if an alkyl alcohol such as methanol, ethanol, propanol, 2-propanol, 1-butanol or 2-butanol is contained, the ejection property of the ink is improved. , Even more effective. These alcohols are preferably contained in the range of 1 to 10% by weight based on the total weight of the ink. Further, if necessary, a surfactant, a rust preventive agent,
It is also possible to contain additives such as antifungal agents, antioxidants, and pH adjusters.

As described above, the ink of the present invention is particularly effective when used in ink jet recording. Inkjet recording methods include a recording method in which mechanical energy is applied to ink to eject droplets and a recording method in which thermal energy is applied to ink to eject droplets by foaming of the ink. The inventive inks are particularly suitable. Further, the polymer used in the present invention has an effect of reducing turbulent frictional resistance in a narrow tube like an ink flow path because a part of its structure is alkylene oxide (Reference: Kazuo Murayama, Naka Mitsui, separate volume). "Chemical industry", Vol 34, p
117 (1990), a smooth ink supply can be realized in a recording system such as an inkjet recording or a ballpoint pen having an ink flow path.

As the ink jet recording apparatus, firstly,
2, 3 and 4 show an example of a head configuration, which is a main part of an apparatus utilizing thermal energy. The head 1 is obtained by bonding a glass, ceramic, silicon or plastic plate or the like having a flow path (nozzle) 2 for passing ink and the heating element substrate 3. The heating element substrate 3 includes a protective layer 4 made of silicon oxide, nitrogen silicon, silicon carbide, etc., an electrode 5 made of aluminum, gold, aluminum-copper alloy, aluminum-silicon alloy, HfB ₂ , TaN, Ta.
A heat generating resistor layer 6 formed of a high melting point material such as Al, poly Si, TaSi, a heat storage layer 7 formed of thermally oxidized silicon, aluminum oxide, etc., and a material having good heat dissipation such as silicon, aluminum, aluminum nitride, etc. It is composed of the substrate 8 to be formed. As an upper layer of the protective layer 4, T
Providing the corrosion-resistant metal layer 4a of a, Nb, Ni, Pt, Tr or the like has the effect of further improving the durability of the recording head.

When a pulsed electric signal is applied to the electrode 5 of the head, the area indicated by h on the heating element substrate 3 rapidly generates heat, and bubbles are generated in the ink in contact with this surface. The generated pressure causes the meniscus 10 to project, and the ink is ejected through the nozzle 2 of the head, and the orifice 1
The recording small droplets 12 are formed from 1 and fly toward the recording material 13. FIG. 4 shows an external view of a multi-head in which a large number of the heads shown in FIG. 2 are arranged. 2 is a sectional view of the head along the ink flow path, and FIG. 3 is a sectional view taken along line XY of FIG.

FIG. 5 shows an example of an ink jet recording apparatus incorporating such a head. In FIG. 5, reference numeral 61 denotes a blade as a wiping member, one end of which is held and fixed by a blade holding member, and has a form of a cantilever. The blade 61 is arranged at a position adjacent to the recording area of the recording head 65, and in the case of this example, is held in a form protruding in the movement path of the recording head 65. Reference numeral 62 denotes a discharge port cap of the recording head 65, which is disposed at a home position adjacent to the blade 61, moves in a direction perpendicular to the moving direction of the recording head 65, contacts the ink discharge port surface, and caps. It has a configuration for performing. Further, 63 is an ink absorber provided adjacent to the blade 61, and like the blade 61, is held in a form protruding in the movement path of the recording head 65. The blade 61, the cap 62, and the ink absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the ink absorber 63 remove water, dust, and the like from the ejection port surface.

Reference numeral 65 has a discharge energy generating means,
A recording head 66 for ejecting ink to record on a recording material facing an ejection port surface provided with ejection ports, and a recording head 65.
And a carriage for moving the recording head 65. The carriage 66 slidably engages with a guide shaft 67, and a part of the carriage 66 is connected (not shown) to a belt 69 driven by a motor 68. As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and its adjacent area.

Reference numeral 51 designates a paper feeding section for inserting a recording material, and 5
A paper feed roller 2 is driven by a motor (not shown). With these configurations, the recording material is fed to the position facing the ejection port surface of the recording head 65, and is ejected to the ejection section provided with the ejection roller 53 as the recording progresses. In the above configuration, when the recording head 65 finishes recording and returns to the home position, the cap 62 of the ejection recovery unit 64 is retracted from the movement path of the recording head 65.
The blade 61 projects into the movement path. as a result,
The ejection port of the recording head 65 is wiped.

When the cap 62 comes into contact with the ejection surface of the recording head 65 to perform capping, the cap 62 moves so as to project into the 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, the ejection opening surface of the recording head 65 is wiped even during this movement.

The above-mentioned movement of the recording head 65 to the home position is performed not only at the end of recording or at the time of ejection recovery, but also at a predetermined interval while adjoining the recording area while the recording head 65 moves in the recording area for recording. Then, the wiping is performed in accordance with this movement. Figure 6
FIG. 4 is a diagram showing an example of an ink cartridge that stores ink to be supplied to a recording head via an ink supply member, for example, a tube.

Reference numeral 40 denotes an ink containing portion for containing the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into this stopper 42, the ink in the ink bag 40 can be supplied to the head. An ink absorber 44 receives the waste ink. As the ink container, it is preferable that the surface in contact with the ink is made of polyolefin, especially polyethylene.

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, but may be the one in which they are integrated as shown in FIG. It is preferably used. In FIG. 7, reference numeral 70 denotes a recording unit, in which an ink containing portion containing ink, for example, an ink absorber is contained, and the ink in the ink absorber has a head portion 71 having a plurality of orifices. It is configured to be ejected as an ink droplet from.

It is preferable for the present invention to use polyurethane as the material of the ink absorber. Further, instead of using the ink absorber, a structure may be adopted in which the ink containing portion is an ink bag in which a spring or the like is provided inside. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere. The recording unit 70 is used in place of the recording head shown in FIG. 5, and is detachable from the carriage 66.

Next, as a form of the second ink jet recording apparatus, a nozzle forming substrate having a plurality of nozzles, a pressure generating element made of a piezoelectric material and a conductive material and arranged to face the nozzles, and the pressure generating element. There is an on-demand ink jet recording head that is provided with an ink that fills the surroundings of the above, and the pressure generating element is displaced by an applied voltage to eject a small droplet of ink from a nozzle.

FIG. 8 shows a configuration diagram of a recording head which is a main part of the recording apparatus. The head is an ink chamber (not shown)
To the ink flow path 80, an orifice plate 81 for ejecting an ink droplet of a desired volume, a vibrating plate 82 for directly exerting a pressure on the ink, and a piezoelectric plate joined to the vibrating plate 82 and displaced by an electric signal. An element 83 and a base 84 for supporting and fixing the piezoelectric element 83, the orifice plate 81, the vibrating plate 82 and the like.

In FIG. 8, the ink flow path 80 is formed of a photosensitive resin or the like, and the orifice plate 81 is formed with a discharge port 85 by electroforming metal such as stainless steel or nickel, punching by press working or laser working. The vibration plate 82 is formed of a metal film of stainless steel, nickel, titanium, or the like, a high-elasticity resin film, or the like.
3 is made of a dielectric material such as barium titanate or PZT.

The recording head having the above-mentioned structure applies a pulsed voltage to the piezoelectric element 83 to generate strain stress,
The energy deforms the vibrating plate joined to the piezoelectric element, vertically pressurizes the ink in the ink flow path, and ejects ink droplets from the ejection port 85 of the orifice plate to perform recording. Such a recording head is used by incorporating it in a recording device similar to that shown in FIG. The detailed operation of the recording device may be performed in the same manner as described above.
Further, the ink of the present invention can be used as an ink for a water-based pen. An example thereof is shown in FIG. FIG. 9 shows a general-purpose ballpoint pen in which a grip portion 400 and an ink filling tube 401 which are held by a finger are made of a highly heat conductive metal thin film so as to have a high thermal conductivity.

[0075]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. The composition ratio in the text is% by weight unless otherwise specified. First, the production of various inks of the present invention will be described. The thermosensitive (thermoreversible) thickening polymer used in this example was obtained by copolymerizing the monomer compositions shown in Table 1.

Table 1-1 Thermosensitive thickening polymer used in the present invention

Table 1-2 Thermosensitive thickening polymer used in the present invention

Note) In Table 1, the number of moles of alkylene oxide (alkylene glycol) added to each polymer-forming monomer (marked with a symbol *) is as follows. Polymer C: propylene oxide = 3, ethylene oxide = 7 Polymer D, F: propylene oxide = 5, ethylene oxide = 10 Polymer E: ethylene oxide = 9, Polymer G: ethylene oxide = 10, propylene oxide = 22 Polymer K: Ethylene oxide = 23

The procedure for preparing the ink is such that an appropriate density (5
(10% to 10%) of the heat-sensitive thickening polymer is prepared in advance in an ion-exchanged water aqueous solution, and is prepared by the method described below.

Examples 1 to 14 (black ink) and Examples 15 to 17 (color ink) [1] First, the case where the coloring material is a dye will be described. Ion-exchanged water, a solvent, an aqueous dye solution, and a surfactant, if necessary, are added to the polymer aqueous solution in this order with stirring to adjust the composition to a predetermined concentration. After stirring for 3 hours, the mixture was filtered through a membrane filter having a pore size of 0.45 μm to obtain the black inks of Examples 1 to 14 of the present invention and Examples 15 to.
Seventeen color inks were prepared.

Table 2-1 Examples 1 to 7 (black ink)

Table 2-2 Examples 8 to 14 (black ink) * Softener manufactured by Sanyo Kasei Co., Ltd.

Table 2-3 Examples 15 to 17 (color ink) ** Acetinol EH is a surfactant manufactured by Kawaken Fine Chemicals Co., Ltd.

Comparative Examples 1 to 2 (black ink), Comparative Examples 3 to 5 (color ink) Further, as Comparative Examples, the same compositions as in Examples 1 and 2 except that the thermosensitive thickening polymer was not used. The above ink was prepared and used as the black ink of Comparative Examples 1 and 2. Similarly, Examples 15 to 1 except that a thermosensitive thickening polymer was not used.
Ink having the same composition as that of No. 7 was prepared and used as color inks of Comparative Examples 3 to 5. In the comparative example, the heat-sensitive thickening polymer was replaced with water.

Example 18, Comparative Example 6 Next, an ink using a pigment as a second coloring material will be described. First, a pigment dispersion is prepared.

(Preparation of Pigment Dispersion Liquid)

The above ingredients are mixed and mixed on a water bath at 70
Heat to 0 ° C to completely dissolve the resin component. Carbon black (trade name: MCF88; Mitsubishi Kasei)
10 parts) and 1 part of 1-propanol were added, and after premixing for 30 minutes, dispersion treatment was performed. Sand glider (Igarashi Kikai Co., Ltd.) was used as the disperser, and zirconium beads (1 mmφ) were used as the grinding media.
The crushing process is performed for 5 hours at a filling rate of the crushing media of 50 vol%. Further, centrifugation treatment (12,000 rpm, 20 minutes) was performed to remove coarse particles to obtain a pigment dispersion liquid.

(Preparation of Ink) Next, an aqueous polymer solution was added to the above dispersion liquid, each component was added so as to have the following composition and mixed for 2 hours to prepare a pigment black ink of Example 18.

Example 18

Furthermore, as Comparative Example 6, an ink having the same composition as in Example 16 was prepared except that the thermosensitive thickening polymer was not used, and the ink was designated as Comparative Example 6. The heat-sensitive thickening polymer was replaced with water. Example 19 and Comparative Example 7 Next, an ink using particles (Example 19) will be described. (Preparation of colorant particle liquid)

First, a fine particle dispersion S2467N (solid content 8.0%, pH 8.0, particle size 1) manufactured by Nippon Synthetic Rubber Co., Ltd.
8 nm) was heated to 60 ° C., and an aqueous dye solution (CI Direct Black 19: 10%) was added thereto.
Is added drop by drop with stirring until the final dye concentration is 5
% To mix and stir for an additional 8 hours. Subsequently, it was filtered through a membrane filter having a pore size of 0.45 μm to obtain a coloring material fine particle liquid.

(Preparation of Ink) Next, an aqueous polymer solution, a solvent, etc. were added to the coloring material fine particle liquid, and the respective components were mixed to give the following composition to prepare an ink of Example 19.

Example 19 (black ink)

Comparative Example 7 (Black Ink) Next, an ink having the same composition as in Example 19 was prepared except that fine particles and a thermosensitive thickening polymer were not used as a comparative example of the above example, and a comparative example. Ink 7 was used. The heat-sensitive thickening polymer was replaced with water. Examples 1 to 1 listed above
The ink performance of each of the ink of No. 9 and the inks of Comparative Examples 1 to 7 was evaluated.

The performance evaluation items for ink jet recording are 1. Optical density (OD value), 2. Feathering, 3.
Bleeding, 4. The four items were water resistance (some inks). The performance evaluation of the water-based pen shown in FIG. Handwriting status (presence or absence of blur) and 6. The presence or absence of bleeding was evaluated. Here, as the water-based pen, Ballsign PGB manufactured by Sakura Crepas Co., Ltd. (water-based ballpoint pen) was partially modified as shown in FIG. In any evaluation, the temperature is 23 ℃
The test was performed in a constant temperature test room with a humidity of 60%. In addition, evaluation item 1,
Only black ink was used for 2, 4, 5, and 6, and evaluation item 3 was color ink.

1. Optical Density (OD Value) A pattern having 5 square 5 mm square solid portions is printed on an A4 size paper, and the optical density of the print sample after 30 minutes or more is measured. Macbeth reflection densitometer R
The measurement was performed at D914, and the average value was used as the OD value. still,
The amount of ejected ink in the solid portion is 12 nl / mm ² .

2. Feathering A4 size dots are recorded on A4 size paper every other nozzle of the recording head, and the dots of the print sample after 30 minutes have passed are observed with a magnifying glass. Bleed or deformed on / 4; 4, Bleeding or deforming on 1/2 of the circumference; 3, Bleeding or deforming on 3/4 of the circumference 2; dots having no arc portion were set to 1 and evaluated in 5 grades.

3. Bleeding The evaluation pattern shown in FIG. 10 was prepared. The bleeding level is divided into 5 levels, and the level of bleeding from which the color mixture bleeds from the 2-color boundary (arrow line) occurs is evaluated as 5 levels (the bleeding is within 1 dot line from the boundary line. 5 is the case where is stopped, and is 4, 3, 2, or 1 depending on which line the bleeding occurs. Part A in the figure is color A,
Part B is a print pattern of color B, and boundaries of two colors are indicated by double-ended arrow lines, and five lines are recorded at an interval of 1 dot line / 1 dot space.

4. Water resistance After the printed matter recorded in the evaluation item 1 was naturally dried for 24 hours, it was immersed in a flat container filled with pure water for 1 minute, taken out, drained, and dried naturally to measure the OD again. The rate of change was calculated. [Water resistance% = OD after immersion in water / initial OD × 100]

5. Handwriting condition Characters are continuously recorded on A4 size paper for about 2 lines and 3
Recording is interrupted for 0 seconds, and two lines are similarly recorded. This operation was repeated, recording was performed until the paper was almost completely filled with characters, and it was visually evaluated whether there was blur.

6. The characters recorded on the blur evaluation item 5 are enlarged and observed with a stereoscopic microscope.
% Or more was regarded as "no blur", and less than 90% was "blurred".

[Evaluator] BJC60 manufactured by Canon Inc. as a recording apparatus for evaluating the ink jet recording described in 1 to 4 above.
0 (360 dpi) was used. The ink was supplied by using a method of filling the intended ink in a dedicated ink container. still,
The BJC 600 incorporates a mechanism for heating the paper during recording. The outline is shown in FIG. The recording apparatus of FIG. 11 is obtained by installing the heating element 100 on the basic recording apparatus of FIG. The heating element 100 is P-8010 manufactured by Nippon Toki Co., Ltd.
Twenty thermal heads 101 are arranged on the A4 horizontal axis, and the applied voltage is 19 V and the applied power is 56 W / mm ² .
By adjusting the drive pulse width and drive frequency, the paper surface temperature can be changed from 30 ° C to 140 ° C at an ambient temperature of 23 ° C.
It is possible to heat in the range of ° C.

In the evaluation, the paper surface temperature is + the transition temperature of the heat-sensitive thickening polymer contained in the ink of each example.
The heating element of the recording apparatus was adjusted to 8 ° C. (the distance between the heating element surface and the paper surface was 0.5 mm). In addition, the evaluation of the corresponding comparative ink was also performed under the same conditions as for recording with the ink of the example. Evaluation items 1 to 6 above
NP-SK paper for electrophotography (Lot
No. OKK10) was used.

[Evaluation Results] Table 3 shows the results of performance evaluation (evaluation items: 1, 2, 4) of the ink of the present invention using BJC600. Also, the inks of Comparative Examples were evaluated in the same manner, and the results are shown in the lower part of Table 3. Further evaluation items 3. Regarding the bleeding of No. 3, the results are shown in Table 4 using the evaluation pattern of FIG. Similarly, Table 5 shows the bleeding evaluation results for Comparative Examples.

Table 3 OD, feathering and water resistance evaluation results of Examples and Comparative Examples

Table 4 Bleeding evaluation results of Examples * In the evaluation pattern of FIG. 10, color A is color ink and color B is black ink.

Table 5 Bleeding evaluation results of comparative examples Next, Table 6 shows the evaluation results when the ink of the present invention was applied to a water-based pen.

Table 6 Results of evaluation with an aqueous pen

[0109]

From the results of Tables 1 to 6, it was found that the ink of the present invention maintained a high OD and was superior in feathering property to the conventional ink. Further, it can be said that bleeding has a large effect of preventing color mixing due to rapid thickening on the paper surface. Further, when the basic or cationic compound is added to the ink of the present invention, the effect of dramatically improving the water resistance of the printed matter is recognized. In particular, the ink of the present invention has excellent effects in high color development, feathering prevention and bleeding prevention in color recording on plain office paper such as electrophotographic paper.

Since the state of the ink of the present invention changes only by the temperature change, the surface pH of the recording material can be applied to various recording materials such as transparency film, cloth, metal plate other than plain paper. It is useful because it is not affected by unevenness or unevenness. As described above, the ink of the present invention does not depend only on evaporation and permeation of the image forming means, and therefore, feathering and mixed color bleeding (bleeding) that are indispensable for high-quality recording while obtaining high OD can be obtained. Problems can be solved at the same time. When the ink of the present invention is used in combination with an ink jet recording device, the effect becomes more remarkable.

[0111]

[Brief description of drawings]

FIG. 1 is a temperature / viscosity relationship diagram of a polymer aqueous solution used in the present invention.

FIG. 2 is a vertical cross-sectional view of a head portion of an inkjet recording device.

FIG. 3 is a cross-sectional view of a head portion of an inkjet recording device.

FIG. 4 is an example of a head having a plurality of nozzles of an inkjet recording apparatus.

FIG. 5 is a perspective view showing an example of an inkjet recording apparatus.

FIG. 6 is a vertical sectional view showing an example of an ink cartridge.

FIG. 7 is a perspective view of a specification in which an inkjet recording head and an ink cartridge are integrated.

FIG. 8 is a vertical view of an inkjet recording head using a piezoelectric element.

FIG. 9 is a schematic view of an aqueous pen using the ink of the present invention.

FIG. 10 Bleeding evaluation pattern

FIG. 11 is a perspective view showing an example of an inkjet recording device provided with a heating element.

[Explanation of symbols]

 51 Paper Feeding Section 52 Paper Feeding Roller 53 Ejecting Roller 61 Wiping Member 62 Cap 63 Ink Absorber 64 Ejection Recovery Section 65 Inkjet Recording Head 66 Carriage 67 Carriage Guide Shaft 68 Carriage Driving Section 69 Driving Belt Section 90 Ink Cartridge 100 Heating Element 101 thermal head 400 metal thin film grip 401 metal ink filling tube

Claims (18)

[Claims] 1. An ink comprising a liquid composition containing a coloring material and a liquid medium, which is one of water-soluble polymer monomers having a cloud point.
A thermosensitive thickening property obtained by copolymerizing a monomer composition containing 50% by weight or more in total of one or more kinds and one or more kinds of monomers represented by the following general formula (I). Polymer (A)
A water-based ink comprising: (However, in the general formula (I), R ₁ is H or C
H ₃ and R ₂ represent H, an alkyl group having 1 to 30 carbon atoms, a (alkyl) phenyl group or an (alkyl-substituted) aminoalkyl group, n is 2 to 4, m is 2 to 4 and l is 2 to 4 , X is 2
˜50, y is an integer of 0 to 50, and z is an integer of 0 to 50, excluding those in which n, m and l have the same number, and those in which n and m or m and l have the same number. . ) 2. The water-based ink according to claim 1, further comprising a fine particle dispersion. 3. The water-based ink according to claim 1, further comprising a basic or cationic compound in the ink in an amount of 0.01 to 5% by weight. 4. The polymer (A) has a molecular weight of 2,000-5.
The water-based ink according to any one of claims 1 to 3, which is a vinyl-based polymer of 0,000. 5. The aqueous ink according to claim 1, wherein x and z of the monomer (I) are the same. 6. The polymer (A) is contained in the ink in an amount of 0.005.
The water-based ink according to claim 1, wherein the water-based ink is contained in an amount of ˜20% by weight. 7. The water-based ink according to claim 1, wherein the transition temperature at which the polymer (A) exhibits a heat-sensitive thickening is in the range of 10 ° C. to 85 ° C. 8. The coloring material is a dye, and 0.1 to 0.1% is contained in the ink.
The ink according to claim 1, which comprises 10% by weight. 9. The water-based ink according to claim 1, wherein the coloring material is carbon black and / or an organic pigment. 10. An ink jet recording method for recording on a recording material by ejecting ink droplets containing a color material and a liquid medium from an orifice of a recording head in response to a recording signal, wherein the ink comprises: <9> An inkjet recording method, which is the water-based ink described in <9>. 11. The ink jet recording method according to claim 10, wherein the recording is performed while the temperature of the recording head is maintained at a transition temperature of the ink or lower during recording. 12. The ink jet recording method according to claim 10 or 11, wherein thermal energy is applied to the ink to eject droplets for recording. 13. The inkjet recording method according to claim 10, wherein recording is performed by causing mechanical energy to act on the ink to eject droplets. 14. A recording unit comprising an ink containing portion containing ink and a recording head portion for ejecting ink as ink droplets, wherein the ink is the ink according to any one of claims 1 to 9. unit. 15. An ink according to any one of claims 1 to 9, wherein the ink is an ink according to any one of claims 1 to 9 in a recording unit including an ink containing portion containing the ink and a recording head portion for ejecting the ink as an ink droplet. A recording unit having a temperature control mechanism for the recording head. 16. An ink jet recording apparatus comprising an ink containing section containing ink and a recording head section for ejecting ink as ink droplets, wherein the recording unit used in the apparatus is the recording unit according to claim 14. An ink jet recording apparatus characterized by the above. 17. An ink jet recording apparatus comprising an ink containing section containing ink and a recording head section for ejecting ink as ink droplets, wherein the recording unit used in the apparatus is the recording unit according to claim 15. An ink jet recording apparatus characterized by the above. 18. The recording material is kept at 30 ° C. in association with the recording operation.
The ink jet recording apparatus according to claim 16 or 17, further comprising a heating mechanism.