JP3127826B2 - Ink composition with excellent water resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION

<Field of the Invention> The present invention relates to an ink composition preferably used for an ink jet recording system, and more specifically,
The present invention relates to an ink composition having excellent ejection stability and forming a water-resistant recorded image when used in an ink jet recording system.

BACKGROUND OF THE INVENTION There are currently several different ink jet recording methods that eject droplets of ink from nozzles and deposit them on a recording medium such as paper. Ink jet recording method is electrostatic suction method, pneumatic feeding method,
Small droplets are generated and ejected by a method utilizing electric deformation of the piezoelectric element, a method utilizing pressure at the time of heating and foaming, and the recording is carried out by attaching the small ink droplets to recording paper.

[0003] Inks used in ink-jet recording systems are well known in the art, and are prepared by dispersing a water-soluble dye solution or a relatively water-insoluble pigment in water or an aqueous solution containing a water-soluble organic solvent. It is common to take the form of a dripped liquid. In general, the performance desired for the ink used in the inkjet recording system is as follows:
1) high recording quality regardless of the type of recording medium; 2) water resistance of the recorded ink regardless of the type of recording medium;
3) Resistance of the recorded ink when the recording surface is lightly rubbed; 4) Quick drying of the recorded image, which does not stain the recorded image even when continuously recorded pages are overlapped; 5) Ink against the temperature. Stability, 6) stability of the ink so that the nozzles of the recording head are not clogged under actual recording conditions, and 7) ink that has lost the solvent due to evaporation is dissolved again in the new ink when it comes into contact with new ink. Or redispersion. The performance listed as 7) is
When the ink jet printer is not used for a long time, the recording head is "cleaned" by applying a pulse to the head with the ink which is stored in the ink reservoir and the evaporation of the solvent component is minimized. is important. It goes without saying that the relative importance of the above performance differs depending on each recording application.

In general, some of the above performances are incompatible with other performances. For example, an ink composed of a liquid in which a relatively hardly soluble pigment is dispersed in an aqueous solution containing water or a water-soluble organic solvent,
It can be formulated to give extremely high recording quality and excellent water resistance of the recorded ink. The waterfastness of such inks is due to the inherent waterfastness of the color pigment. However, the pigment is not dissolved but dispersed in water or an aqueous solution containing a water-soluble organic solvent. Therefore, this type of ink may lack stability at extreme temperatures or actual printing conditions. Further, as described above, it is extremely difficult to formulate such an ink such that the pigment is redispersed when the fresh ink and the dried ink are brought into contact (for example, at the head).

In contrast, an ink in which a water-soluble dye is dissolved in water or an aqueous solution containing a water-soluble organic solvent forms a fast-drying recorded image and has excellent stability against extreme temperatures and actual recording conditions. Has the property. Because the dye is water-soluble,
When the fresh and dried inks are brought into contact, the dye can be easily redissolved. It is relatively easy to formulate this type of ink. However, since the dye is water-soluble, it is difficult to obtain a water-resistant recorded image on all types of recording media.

[0006] In order to solve the above-mentioned problems in an ink comprising a relatively insoluble pigment dispersed in water or an aqueous solution containing a water-soluble organic solvent, an ink containing an alkali-soluble polymer resin is used. Compositions have been proposed.
JP-A-53-114985 discloses an ink composition using a polymer resin containing a phenol functional group and containing an emulsion of a water-insoluble pigment or disperse dye. It is alleged that such an ink composition provides better color development than an ink containing no polymer. The particle size of the water-insoluble pigment or dispersed dye stabilized by the polymer is described as less than 3 μm.

JP-A-62-11782 and JP-B-5-62632 use an ink composition containing a polyester resin containing a sulfonic acid functional group and containing an emulsion of a water-insoluble dye or a disperse dye. Is disclosed. It is alleged that such an ink composition can provide better water resistance than an ink containing no polymer. This publication does not describe the particle size of the water-insoluble or dispersed dye stabilized by the polymer.

JP-A-2-248475 discloses an ink composition containing a polymer dispersion containing a carboxylic acid functional group and containing a polymer dispersion containing either a water-soluble dye or a water-soluble pigment. Is disclosed. It is alleged that such an ink composition can provide better water resistance and light resistance than an ink containing no polymer. According to this publication, the alkali-soluble resin containing the ink composition is stable at 50 ° C. for three months.

The alkali-soluble polymers used in these three examples appear to contribute significantly to the stability of the dispersions of insoluble pigments and dyes containing polymer particles. However, polymer particles containing a pigment or dye are not dissolved but dispersed in water or an aqueous solution containing a water-soluble organic solvent. Therefore, there is still room for further improvement in that it is not completely stable at extreme temperatures and actual recording conditions, and that particles settle out over a long period of time. Furthermore, this type of ink cannot be easily redispersed when the dried ink and fresh ink are brought into contact.

[0010] In order to solve the above-mentioned problems in the ink comprising water or an aqueous solution containing a water-soluble organic solvent and a water-soluble dye, an ink composition using an alkali-soluble polymer resin has been proposed. . Japanese Patent Publication 40-6581
In Japanese Patent Application Publication No. JP-A-2002-209, there is described an ink composition comprising a polymer resin containing a carboxylic acid functional group and a water-soluble basic dye. It is said that such an ink composition can impart more excellent water resistance than an ink containing no polymer.

JP-A-62-64875 and JP-B-5-62633 describe an ink composition containing a polymer resin containing a sulfonic acid functional group and a water-soluble basic dye. ing. It is alleged that such an ink composition can provide better water resistance than an ink containing no polymer.

JP-A-5-230413 describes an ink composition comprising a styrene polymer resin containing a carboxylic acid functional group and a water-soluble basic dye. The average molecular weight of the polymer used here is 150
0 to 30,000, and the acid value of the polymer is 150 to 300.
It is. It is alleged that such an ink composition can provide better water resistance than an ink containing no polymer.

The alkali-soluble polymers used in these three examples seem to contribute significantly to water resistance. However, the recorded images are not completely water-resistant on all types of recording media. All of these conventional techniques leave room for improvement, and it can be said that there is still a desire for ink compositions having excellent water resistance.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink composition capable of forming a water-resistant recorded image on paper irrespective of the type of paper, and in particular, to provide an ink composition preferably used for ink jet recording. And

Another object of the present invention is to provide an ink composition in which a recorded image dries quickly.

Further, the present invention provides an ink composition that does not clog the nozzles of the recording head and that does not eject ink droplets in a curve that is not perpendicular to the recording head (no flight bending). It is an object.

Still another object of the present invention is to provide an ink composition which can easily re-dissolve dried ink when the dried ink composition is brought into contact with a fresh ink composition.

The ink composition according to the present invention comprises water, an alkali-soluble resin containing a phenol functional group, a basic dye, and both the alkali-soluble polymer containing a phenol functional group and the basic dye. And an amount of alkali that can be completely dissolved in the aqueous solution.

[0019]

DETAILED DESCRIPTION OF THE INVENTION The ink composition of the present invention can be used in any of the ink jet recording systems known in the art to eject ink through small diameter nozzles (nozzles generally less than 50 microns in diameter). Can also be preferably used. The ink composition of the present invention also includes
It can also be used for writing instruments such as pens.

<Alkali-Soluble Resin Containing Phenol Functional Group> The alkali-soluble resin containing a phenol functional group used in the present invention is a mixture with water, and when a certain amount of alkali is added, it is dissolved in water. is necessary.

Alkali-soluble resins containing phenolic functional groups are available in several different grades from Arakawa Chemical Industries, Ltd. (Chuo-ku, Osaka) under the trade name Tamanor. Further, several different grades of alkali-soluble resins containing phenol functional groups are commercially available from Sumitomo Durez Co., Ltd. (Chiyoda-ku, Tokyo) under the trade name of Durez.

<Basic Dye> Examples of the basic dye used in the present invention include Aizen Auramine OW 100
(Trade name, CI Basic Yellow 2 manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Cathilon Yellow 3GLH (trade name, CI Basic Yellow 11 manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Cathilon Brilliant Yellow 5G
LH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., CI Basic Yellow 13), Aizen Cathilon Yellow GLH
(Trade name, CI Basic Yellow 14 manufactured by Hodogaya Chemical Co., Ltd.), Aizen Cathilon Yellow 3RLH
(Trade name, CI Basic Yellow 36, manufactured by Hodogaya Chemical Co., Ltd.), Baycolor Golden Yellow GLE 200
% (Trade name, manufactured by Bayer Ltd.), Baycolor Yellow
8GLS 200% (trade name, manufactured by Bayer Ltd.), Baycolor
Yellow 7GLL 200% (trade name, manufactured by Bayer Corporation),
Aizen Cathilon Orange GLH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., CI Basic Orange 2), Aizen
Cathilon Orange RH (trade name, CI Basic Orange 22 manufactured by Hodogaya Chemical Industry Co., Ltd.), Rhodamine
6G (Catalog number 25,243-3, Aldrich Japan
Company,. Basic Red 1), Aizen Astra Phloxine F
F Concentrated (trade name, CI Basic Red 12 manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Cathilon
Pink FGH (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I.
I. Basic Red 13), Aizen Cathilon Brillia
nt Red4GH (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I.
I. Basic Red 14), Aizen Cathilon Red GTL
(Trade name, CI Basic Red 18 manufactured by Hodogaya Chemical Co., Ltd.), Aizen Cathilon Brilliant Pink
BH (trade name, CI Basic Red 36, manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Cathilon Brilliant Sca
rlet RH (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I.
I. Basic Red 37), Aizen Cathilon Red GL
H (trade name, CI Basic Red 38, manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Cathilon Red BLH (trade name, CI Basic Red 39, manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Cathilon Bordeaux RLH (product name,
Hodogaya Chemical Industry Co., Ltd., C.I. I. Basic Red 40), Baycolor Red 5BL 200% (trade name, manufactured by Bayer KK), Baycolor Red BBL 200% (trade name, manufactured by Bayer KK), Baycolor Red FBL 200% (trade name, manufactured by Bayer KK), Aizen Methyl Violet Pure Speci
al (trade name, CI Basic Violet 1 manufactured by Hodogaya Chemical Co., Ltd.), Aizen Crystal Violet Ext
ra Pure (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I.
I. Basic Violet 3), Aizen Cathilon Red
6BH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., CI.
Basic violet 7), Aizen Rhodamine BH
(Trade name, CI Basic Violet 10 manufactured by Hodogaya Chemical Co., Ltd.), Aizen Cathilon Brilliant R
ed 3BPH (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I.
I. Basic Violet 15), Aizen Cathilon V
iolet FRLH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.
C. I. Basic Violet 25), Aizen Cathil
on Red 7BNH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.
C. I. Basic Violet 27), Aizen Cathil
on Violet 3BLH (trade name, CI Basic Violet 28, manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Br
illiant Basic Cyanine 6GH (trade name, CI Basic Blue 1 manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Ba
sic Pure Blue 5GH (trade name, CI Basic Blue 3 manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Victoria P
ure Blue BOH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.
C. I. Basic Blue 7), Aizen Methylene Blue
FZ (trade name, CI Basic Blue 9 manufactured by Hodogaya Chemical Co., Ltd.), Aizen Methylene Blue BH Concen
trated (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I.
I. Basic Blue 9), Aizen Victoria Blue BH
(Trade name, CI Basic Blue 26, manufactured by Hodogaya Chemical Co., Ltd.), Aizen Marine Blue BNX (trade name,
Hodogaya Chemical Industry Co., Ltd., C.I. I. Basic Blue 28), Aizen Cathilon Blue 5GLH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., CI Basic Blue 4)
5), Aizen Cathilon Blue 3RLH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., CI Basic Blue 47),
Aizen Cathilon Navy Blue GLH (trade name, CI Basic Blue 64, manufactured by Hodogaya Chemical Co., Ltd.), Ai
zen Cathilon Blue GLH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., CI Basic Blue 65), Aizen Cath
ilon Blue NBLH (trade name, CI Basic Blue 66, manufactured by Hodogaya Chemical Co., Ltd.), Aizen Cathilon
Blue NRLH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.
C. I. Basic Blue 67), Aizen Cathilon Blu
e 2RLH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., CI.
Basic Blue 68), Baycolor Blue 5GL 200%
(Product name, manufactured by Bayer Corporation), Baycolor Blue F2RL
200% (trade name, manufactured by Bayer Ltd.), Baycolor Blu
eBG 200% (trade name, manufactured by Bayer Ltd.), Aizen Di
amond Green GH (trade name, CI Basic Green 1 manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Malachit
e Green (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., C.I.
I. Basic Green 4), Aizen Cathilon Brown 3
GLH (trade name, CI Basic Brown 11 manufactured by Hodogaya Chemical Industry Co., Ltd.), Aizen Cathilon Red Brown 2
GLH (trade name, CI Basic Brown 11 manufactured by Hodogaya Chemical Industry Co., Ltd.).

<Alkali> The alkali used in the present invention is not particularly limited as long as it dissolves an alkali-soluble resin containing a phenol functional group and a basic dye in the ink composition.

The alkali which can be preferably used in the present invention includes an inorganic base and an organic base.

As the inorganic base, NaOH, KOH, L
iOH and CsOH. Examples of the organic base include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

<Ink Composition> The following are mere assumptions and the ink composition according to the present invention can form a stable and water-resistant print on the condition that it is not understood with the intention of limiting the present invention. The reason is considered as follows.

In the ink composition according to the present invention,
It is considered that the basic dye is attached to the alkali-soluble resin containing a phenol functional group by the attraction of both charges. As a result, it is considered that the coloring component can be stably present in the ink composition.

On the other hand, the reason why the water resistance is exhibited on the recording medium is considered to be the following two reasons. First, the pH of tap water is generally acidic. When the water adheres to the ink on the recording medium, a neutralization reaction occurs with the base in the ink. The second is that the amount of adhering water is much larger than the amount of ink on the recording medium. When diluted in a large volume of water, the solution becomes less basic.

Although it is difficult to separate the above two principles, even if water adheres to the ink on the recording medium,
Since it is not possible to have sufficient basicity to redissolve the resin and dye in the ink, it is considered that high water resistance of the printed matter can be obtained.

The amount of the alkali-soluble resin containing a phenol functional group in the ink composition may vary depending on the type of polymer, the molecular weight of the polymer, and other ink components (dye, alkali, It may be appropriately determined in consideration of additives used as required, for example, a water-soluble monoalkyl ether of alkylene glycol or polyalkylene glycol), but is preferably in the range of about 1 to 15% by weight. Within this range, it is possible to solubilize a sufficient amount of the dye to obtain a recorded image having a reasonable concentration, and even if the alkali-soluble resin contains a phenol functional group having a high molecular weight, the appropriate ink can be used. A viscosity is obtained. When used for inkjet recording, the amount of the alkali-soluble polymer containing a phenol functional group is preferably determined so that the viscosity of the ink composition at 20 ° C. is 10 cps or less.

The basic dye is present in an amount of 0.05 to 3 parts by weight, more preferably 0.2 to 1.2 parts by weight, based on the weight of the alkali-soluble resin containing a phenol functional group. preferable.

The amount of the alkali is not particularly limited as long as it is an amount that completely dissolves the alkali-soluble polymer containing a phenol functional group and the basic dye, but may be smaller than the minimum amount required to dissolve the polymer and the dye. Is preferably a slightly excessive amount of alkali. To obtain greater ink stability, it is preferred that the amount of alkali be at least 10% greater than the minimum required to dissolve the polymer and dye.

The minimum amount of alkali required to dissolve the alkali-soluble resin containing a phenolic functional group and the basic dye is determined by the amount of optional additives used, such as alkylene glycols or water-soluble monoalkyl ethers of polyalkylene glycols. Slightly affected by volume. Therefore, when an optional additive is used, it is advantageous to add the additive before adding the alkali, but the additive is not limited to this.

The ink composition according to the present invention may contain a water-soluble monoalkyl ether of an alkylene glycol or a polyalkylene glycol in order to give a recorded image a quick drying property. By adding these, the drying property of printing can be improved. However, for certain combinations of polymers and dyes, it is also possible to dry the recorded image quickly enough without adding a water-soluble monoalkyl ether of an alkylene glycol or polyalkylene glycol.

The water-soluble monoalkyl ether of alkylene glycol or polyalkylene glycol includes
For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-i-propyl ether, ethylene glycol mono-n
-Butyl ether, ethylene glycol mono-s-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-i-propyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-s-butyl ether, Triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol mono-n-propyl ether, triethylene glycol mono-i-propyl ether, triethylene glycol mono-n-butyl ether, triethylene glycol mono-s-butyl ether , Propylene glycol monomethyl ether, and propylene Recall monoethyl ether. The amount of water-soluble monoalkyl ether of alkylene glycol or polyalkylene glycol is 1
It is preferably from 40% to 40%, more preferably from 5% to 30%.

The ink composition according to the present invention may contain, in addition to the above components, a wetting agent such as glycerin, a bactericide, a surfactant, and other water-soluble resins that can be used for adjusting the viscosity of the ink. it can.

The ink composition according to the present invention is preferably prepared by first preparing a homogeneous mixture of a dye and an alkali-soluble resin containing phenolic functional groups and dissolving in a sufficient amount of alkali-added water. Can be. Adding optional additives, such as water-soluble monoalkyl ethers of alkylene glycols or polyalkylene glycols, to the mixture before dissolving the homogeneous mixture in water will generally further enhance dissolution. preferable.

A homogeneous mixture of a basic dye and an alkali-soluble resin containing phenolic functional groups can be prepared by various methods. One preferred method is to mix the dye with an alkali-soluble resin containing a phenol functional group at high temperature and high shear. Preferred temperatures are higher than the softening point of the alkali-soluble resin containing phenolic functional groups and lower than the decomposition temperature of the basic dye. High shear rates can be effected using mixing equipment designed for extrusion of plastics. Another preferred method is to dissolve both the polymer and the dye in mutually compatible volatile solvents and then spray dry the solution. In another method, the dye is soluble and the polymer is insoluble, but the polymer is swelled with a solvent that can swell. High temperatures and pressures can be used to increase the rate at which the dye penetrates the swollen polymer.

The ink composition according to the present invention is produced by dissolving an alkali-soluble resin containing a phenol functional group in water in the presence of an alkali, adding a basic dye to the solution, and dissolving it. Is also good.

[0040]

The following examples further illustrate the invention.

Example 1 In a stainless steel beaker, 2.5 g of Aizen Cathilon Brilliant Yellow 5GLH 200% (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was mixed with 2.5 g of a phenol resin, Tamanol PA (trade name, Arakawa Chemical Industry Co., Ltd.). Made by company)
5 g. While heating the mixture at 180 ° C. for 10 minutes, the mixture was stirred vigorously using a stainless steel spatula. After heating and mixing, a homogeneous translucent glassy mixture was obtained. After cooling to room temperature, the glassy resin-dye material is broken into small pieces and
Transferred to 1 l sample bottle. 3.1 g of 40% NaOH aqueous solution
And 79.4 g of ultrapure water were also placed in the sample bottle. The mixture was stirred at room temperature for 6 hours, during which time the glassy resin-dye material dissolved. 10 g of diethylene glycol monoethyl ether were added and the mixture was stirred for another hour.
The mixture was filtered through a 5 μm stainless steel mesh. The viscosity of this ink composition is 3.8 c at 20 ° C.
ps and pH was 12.3.

Example 2 In a stainless steel beaker, 2.5 g of Aizen Cathilon Yellow 7G-DP (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was mixed with phenol resin Tamanol P.
A (trade name, manufactured by Arakawa Chemical Industry Co., Ltd.) 5 g. The mixture was heated and mixed in the same manner as in Example 1 to obtain a homogeneous translucent glassy mixture. In the same manner as in Example 1, a glassy resin-dye material was dissolved in 79.3 g of ultrapure water and 3.2 g of a 40% aqueous NaOH solution. 10 g of diethylene glycol monomethyl ether were added and the mixture was stirred for another hour. The mixture was filtered through a 5 μm stainless steel mesh. The viscosity of this ink composition was 3.9 cps at 20 ° C., and the pH of the ink composition was 12.7.

(Example 3) Aizen Cathilon Brilliant Pink CD-BH Concentrated in a stainless steel beaker
2.5 g (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was mixed with 5 g of a phenolic resin Tamanol PA (trade name, manufactured by Arakawa Chemical Industry Co., Ltd.). The mixture was heated to 190 ° C. and mixed in the same manner as in Example 1 to obtain a homogeneous translucent glassy mixture. In the same manner as in Example 1, a glassy resin-dye material was dissolved in 80 g of ultrapure water and 2.5 g of a 40% aqueous NaOH solution. 10 g of triethylene glycol mono-n-butyl ether are added, and the mixture is
Stirred for hours. The mixture was filtered through a 5 μm stainless steel mesh. The viscosity of the ink composition was 4.2 cps at 20 ° C., and the pH of the ink composition was 1
2.1.

Example 4 Aizen Astra Phloxine FF Concentrated (trade name, in a stainless steel beaker)
2.5 g of Hodogaya Chemical Co., Ltd.) and 5 g of phenol resin Tamanol PA (trade name, Arakawa Chemical Co., Ltd.)
And mixed. The mixture was heated to 190 ° C. and mixed in the same manner as in Example 1 to obtain a homogeneous translucent glassy mixture. In the same manner as in Example 1, 80.1 g of ultrapure water and 2.4% of a 40% aqueous NaOH solution were prepared using a glassy resin-dye material.
g. 10 g of diethylene glycol mono-n-butyl ether were added and the mixture was stirred for another hour. The mixture was filtered through a 5 μm stainless steel mesh. The viscosity of this ink composition was 4.degree.
0 cps, and the pH of the ink composition was 12.2.

(Example 5) In a stainless steel beaker, 2.5 g of Aizen Cathilon Red 7BH 200% (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was mixed with 2.5 g of a phenol resin, Tamanol P.
A (trade name, manufactured by Arakawa Chemical Industry Co., Ltd.) 5 g. The mixture was heated to 170 ° C. as in Example 1,
Mixing yielded a homogeneous translucent glassy mixture. In the same manner as in Example 1, a glassy resin-dye material was dissolved in 79.7 g of ultrapure water and 2.8 g of a 40% aqueous NaOH solution. 10 g of diethylene glycol mono-n-butyl ether were added and the mixture was stirred for another hour. 5μ
The mixture was filtered through m stainless steel mesh.
The viscosity of this ink composition is 3.5 cps at 20 ° C.
And the pH of the ink composition was 12.6.

(Example 6) In a stainless steel beaker, 2.5 g of Aizen Cathilon Blue 5G-DP (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was mixed with 2.5 g of a phenol resin, Tamanol PA.
(Trade name, manufactured by Arakawa Chemical Industry Co., Ltd.).
The mixture was heated and mixed in the same manner as in Example 1 to obtain a homogeneous translucent glassy mixture. In the same manner as in Example 1, a glassy resin-dye material was dissolved in 79.9 g of ultrapure water and 2.6 g of a 40% aqueous NaOH solution. 10 g of diethylene glycol mono-n-butyl ether were added and the mixture was stirred for another hour. The mixture was filtered through a 5 μm stainless steel mesh. The viscosity of this ink composition was 4.2 cps at 20 ° C., and the pH of the ink composition was 12.1.

(Example 7) In a stainless steel beaker, 2.5 g of Aizen Cathilon Pure Blue 5GH Concentrated (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was mixed with phenol resin Tamanol PA (trade name, Arakawa Chemical Industry Co., Ltd.) Made)
5 g. The mixture was heated and mixed in the same manner as in Example 1 to obtain a homogeneous translucent glassy mixture.
In the same manner as in Example 1, a glassy resin-dye material was dissolved in 79.6 g of ultrapure water and 2.9 g of a 40% aqueous NaOH solution. 10 g of diethylene glycol monoethyl ether were added and the mixture was stirred for another hour. 5 μm
The mixture was filtered through a stainless steel mesh. The viscosity of this aqueous ink composition was 3.9 c at 20 ° C.
ps, and the pH of the ink composition was 12.8.

Example 8 In a stainless steel beaker, 2.5 g of Aizen Brilliant Basic Cyanine 6GH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was mixed with 2.5 g of a phenol resin, Tamanol PA (trade name, manufactured by Arakawa Chemical Industry Co., Ltd.) ) 5 g. The mixture was heated and mixed in the same manner as in Example 1 to obtain a homogeneous translucent glassy mixture. Example 1
In the same manner as described above, the glassy resin-dye material is
Dissolved in 9.2 g and 3.3 g of 40% aqueous NaOH solution. 10 g of diethylene glycol mono-n-butyl ether were added and the mixture was stirred for another hour. 5 μm
The mixture was filtered through a stainless steel mesh. The viscosity of this aqueous ink composition is 4.4 c at 20 ° C.
ps, and the pH of the ink composition was 12.5.

Example 9 Aizen Cathilon Orange RH
2.5 g (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was dissolved in 47.5 g of ultrapure water with stirring. Phenolic resin Tamanol PA (trade name, Arakawa Chemical Industry Co., Ltd.) 5
g and 40 g of a 40% aqueous NaOH solution were added to 32
g and stirred for 2 hours. To this mixture under stirring is added ethylene glycol mono-n-butyl ether 10
g was added and the mixture was stirred for another hour. To this mixture with stirring, the colorant solution was added dropwise. After the addition was completed, the mixture was further stirred for 4 hours. The mixture was filtered through a 5 μm stainless steel mesh. The viscosity of this aqueous ink composition is 4.6 cps at 20 ° C.
And the pH of the ink composition was 12.5.

Example 10 Aizen Cathilon Brilliant
Scarlet RH (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.)
2.5 g was dissolved in 47.5 g of ultrapure water with stirring. 5 g of phenolic resin Tamanol PA (trade name, manufactured by Arakawa Chemical Industry Co., Ltd.) and 40% NaOH aqueous solution 3.1
g was added to 31.9 g of ultrapure water and stirred for 2 hours. To this mixture under stirring, add diethylene glycol mono-
10 g of n-butyl ether were added and the mixture was stirred for another hour. To this mixture with stirring, the colorant solution was added dropwise. After the addition was completed, the mixture was further stirred for 4 hours. The mixture was filtered through a 5 μm stainless steel mesh. The viscosity of this aqueous ink composition is 20
At 4.1C, the pH of the ink composition was 4.1 cps.

(Example 11) Aizen Victoria Blue BH
2.5 g (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was dissolved in 47.5 g of ultrapure water with stirring. Phenolic resin Tamanol PA (trade name, Arakawa Chemical Industry Co., Ltd.) 5
g and 40% NaOH aqueous solution 2.9 g
2.1 g and stirred for 2 hours. To this stirred mixture was added 10 g of diethylene glycol mono-n-butyl ether and the mixture was stirred for another hour. To this mixture with stirring, the colorant solution was added dropwise. After the addition was completed, the mixture was further stirred for 4 hours. 5
The mixture was filtered through a μm stainless steel mesh. The viscosity of this aqueous ink composition was 4.0 cps at 20 ° C., and the pH of the ink composition was 12.2.

Comparative Example 1 A styrene-acrylic acid resin JONCRYL 62 (trade name, manufactured by SC Johnson Polymer) having a composition similar to that of the pigment type ink described in JP-A-5-230413 was included. A pigment type ink was manufactured. The composition of this pigment type ink is JONCRYL 62 (21
%), Color Black SB-5 (7.1%, trade name, Degussa
Co., Ltd.), Neocol YSK (0.4%, trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), ethylene glycol (6.5%), and ultrapure water (65%). The mixture was mixed for several hours to obtain a homogeneous mixture.

Comparative Example 2 A water-soluble basic dye and a styrene-acrylic acid resin JONCRYL 680 (trade name, manufactured by SC Johnson Polymer) having a composition similar to that of Example 8 of JP-A-5-230413 were used. An ink was produced. CI Basic Red 12 instead of CI Basic Blue 7
(Aizen Astra Phloxine FF Conc., Trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) was used. The composition of the ink containing the water-soluble basic dye is CI Basic Red 12 (2.5
%), JONCRYL 680 (7.5%), 28% ammonia solution (0.87%), triethanolamine (2.13
%), Propylene glycol (15%), and ultrapure water (72%). The same manufacturing method as described in Example 8 of JP-A-5-230413 was used.

<Evaluation Test> The inks produced as described above were evaluated by the following tests.

1) Continuous Recording The ink composition sample was degassed and recorded continuously at 25 ° C. and 30% relative humidity for 24 hours using MJ-700V2C (trade name, manufactured by Seiko Epson Corporation). The weight of ejected ink per page was measured after 5 minutes and every 6 hours. The maximum sensitivity of the balance was 0.01 g. The results of this test were as follows:
5 or less (◎), the standard deviation of 5 measurements exceeds 0.5,
1.0 or less (○), the standard deviation of 5 measurements exceeds 1,
The evaluation was performed using a value of 1.5 or less (△) and a standard deviation of five measurements exceeding 1.5 (x).

2) Discontinuous Recording The ink composition sample was degassed and recorded using a line pattern program using all the nozzles of the recording head.
The recording program was executed for 2 hours at 25 ° C. and 30% relative humidity using MJ-700V2C (trade name, manufactured by Seiko Epson Corporation). The recording program used was a discontinuous program in which recording was performed for 1 minute and then the operation of pausing for 1 minute was repeated. During the idle period, the recording head was not covered to prevent the ink from drying. The sample recorded at the end of the 2 hour test was examined under a microscope and evaluated according to the following criteria. That is, there was no evidence of clogging, all of the dots were observed at the last restart of the recording program (◎), there was slight clogging, and dots 1-5 were missing at the last restart of the recording program. (○), considerable clogging, missing 6-20 of dots at the last restart of the recording program (、), unacceptable clogging, dot at the last restart of the recording program 21 or more were evaluated as missing (x).

3) Solid Printing Drying Rate The Xerox P paper (trade name, Fuji Xerox Co., Ltd.) was used to degas the ink composition sample and use a program to record a rectangular block of 1 cm × 7.2 cm with the highest density solid printing. Manufactured). The sample was recorded using MJ-700V2C (trade name, manufactured by Seiko Epson Corporation). Immediately after the block recording was completed, the time until the glossy, light-reflecting liquid ink completely disappeared was measured. The following criteria, that is, 1 second or less (１), more than 1 second, 2 seconds or less (○), 2 seconds or more, 5 seconds or less (△), and 5 seconds or more (x) were evaluated. .

4) Re-dissolution / re-dispersion of dried ink 1 μl of an ink sample was placed in a Teflon block (15 mm × 10
mm × 1 mm) and left to dry at room temperature for 24 hours. The sample was further dried at 40 ° C. for 72 hours. next,
The Teflon block carrying the sample was immersed in 20 ml of the original ink composition. One hour later, it was removed using tweezers and inspected. If some of the dried ink remained on the Teflon block, the sample was returned to the original ink composition. 1) immersion, 2) removal, and 3)
The test sequence was repeated at 1 hour intervals for up to 5 hours, or until there was no evidence of sample remaining on the Teflon block. Evaluation was performed using the following criteria, that is, 1 hour or less (（), more than 1 hour, 2 hours or less (（), 2 hours or more, 4 hours or less (△), and 4 hours or more (×). .

5) Water Resistance of Recorded Sample The ink composition sample was degassed, and Xerox P and R paper (trade name, Fuji Xerox Co., Ltd.) were used using MJ-700V2C (trade name, manufactured by Seiko Epson Corporation). Characters) and figures were recorded. The recorded sample was left to dry for 24 hours. A drop of water (0.05 ml each drop) was then carefully placed on both the recorded letters and graphics. The moistened sample was dried for 24 hours. The water resistance of the recorded image was evaluated according to the following criteria, ie, the two types of paper showed that the wet sample did not change with respect to both the character and the figure when compared with the non-moist character (（), 2 With the paper type, the wet recording sample did not change with respect to the characters, but showed slight fading and / or bleeding with respect to the solid image with the highest density (）). Indicates that only one type of paper has not changed, but the highest density solid printed figure shows slight fading and / or bleeding on both types of paper (△). Indicates discoloration and / or bleeding (x).

The inks of the above Examples and Comparative Examples according to the present invention were evaluated by the above test methods. The result is the first
As shown in the table.

[0061]

[Table 1]

Claims (8)

(57) [Claims] 1. An ink composition in which water, an alkali-soluble resin containing a phenol functional group, a basic dye, and both the alkali-soluble polymer containing a phenol functional group and the basic dye are completely dissolved in the ink composition. An ink composition comprising an amount of an alkali. 2. The ink composition according to claim 1, comprising 0.05 to 3 parts by weight of the basic dye based on the alkali-soluble resin containing the phenol functional group. 3. The ink composition according to claim 1, further comprising a water-soluble monoalkyl ether of an alkylene glycol or a polyalkylene glycol. 4. The ink has a viscosity of 10 cp at 20 ° C.
The ink composition according to any one of claims 1 to 3, which is less than s and is used for inkjet recording. 5. The alkali-soluble resin containing a phenol functional group is in an amount of 1 to 15% by weight, and the amount of the basic dye is 0.2 to 1.2% by weight based on the weight of the alkali-soluble resin having a phenol functional group. The ink composition according to any one of claims 1 to 4, which is a part. 6. Further, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether,
The ink composition according to any one of claims 1 to 5, further comprising a water-soluble monoalkyl ether of an alkylene glycol or a polyalkylene glycol selected from a mixture thereof. 7. The method for producing an ink composition according to claim 1, wherein the alkali-soluble resin containing a phenol functional group and the basic dye are higher than the softening point of the polymer. Mixed at a temperature lower than the decomposition temperature of the dye,
Dissolving the resulting mixture of polymer and dye in water to which an alkali-soluble resin containing a phenolic functional group and an alkali have been completely added to dissolve the basic dye. 8. The method for producing an ink composition according to claim 1, wherein an alkali-soluble resin containing a phenol functional group is dissolved in water in the presence of an alkali, and further comprising a basic dye. Dissolving the compound.