JP3086531B2 - Recording liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid for ink jet recording.

[0002]

2. Description of the Related Art Ink jet recording is capable of low-noise, high-speed printing, and is also suitable for color printing. Therefore, it is spreading rapidly recently. In the ink jet recording, recording liquid is discharged as droplets by a method such as pressurization or heating using an electric signal, and the recording liquid is adhered to a recording member such as paper to perform recording.

A recording liquid for ink jet recording mainly comprises additives such as a wetting agent, a dye, and water, and most of them are water-soluble. Dyes are important recording liquid components for visually and optically transmitting desired figures and characters by coloring paper and the like, and water is a transport medium for transferring the dyes to paper and the like.

[0004]

Among the recording liquids for ink jet recording, those using emulsions are disclosed in JP-A-54-146109 and JP-A-58-4.
No. 5,272, JP-A-59-30873, and JP-A-3-6270. These recording liquids are prepared by dispersing dye-containing latex, colored latex, or polymer latex having a specific structure in water to improve recording reflection density and water / light resistance. . However, it is difficult to obtain a recording having a sufficient reflection density with a conventional recording liquid, and there are also problems in the coating property of the dye and the storage stability.

Accordingly, an object of the present invention is to provide a recording liquid which is excellent in coatability and storage stability of a dye or a pigment and can obtain a recording having a high reflection density.

[0006]

According to the present invention, there is provided a recording liquid comprising a non-crosslinked vinyl polymer having a melting temperature of 50 ° C. or higher as a main component and an average particle size of 0.2 to 2.0 μm. And a water-soluble polymer having a melting temperature of 50 ° C. or higher, a dye or a pigment, and water.

[0007]

The recording liquid of the present invention is excellent in coatability of a dye or a pigment and extremely excellent in storage stability, since a dye or a pigment is dispersed in a water-soluble polymer and is effectively coated with an emulsion.

The emulsion used in the present invention contains a vinyl polymer as a main component, does not dissolve in water, has excellent affinity for hydrogen bonding with a dye or a pigment, and can form a stable emulsion. If you can use it. In addition, it must be present in water homogeneously without being separated from dyes or pigments.

The average particle size of the emulsion is 0.2 μm.
m and 2.0 μm or less. When the average particle size is in this range, interaction between the dye or pigment and the emulsion easily occurs, and the dye or pigment can be effectively coated. If the average particle size is smaller than 0.2 μm, the emulsions will associate with each other and the recording liquid will be in a very unstable state. On the other hand, the average particle size is 2.0 μ
If it is larger than m, the particle size of the emulsion is too large as compared with the dye or pigment, and it is difficult to effectively coat the dye or pigment.

Further, the melting temperature of the non-crosslinked vinyl polymer which is the main component of the emulsion must be 50 ° C. or higher. This is because the surface of the dye or pigment adsorbed on the paper or the like after recording is coated with a vinyl polymer, and this state is stably maintained. If the melting temperature is lower than 50 ° C., if the recorded paper or the like is left for a long time in a stacked state, the dye or pigment is adsorbed and the paper or the like is stained.

Examples of the non-crosslinked vinyl polymer which is a main component of the emulsion include a homopolymer of vinyl acetate, a copolymer of vinyl acetate and ethylene, and a copolymer of vinyl acetate and acrylamide. .

The emulsion containing a vinyl polymer as a main component used in the present invention is more powerful because it can quickly coat its surface with a kind of surface active effect when the dye or pigment is adsorbed on paper or the like. Water resistance can be exhibited.

As the water-soluble polymer, any polymer which has a large polar structure and can be easily dissolved in water and has a strong interaction with dyes or pigments to give a uniform aqueous solution can be used. For example, polyvinylpyrrolidone, polyvinyl oxazolidone, polyvinyl alcohol, polyacrylic acid,
Examples include polyethylene oxide. Further, in order to keep the dye or pigment adsorbed on the paper after recording in a stable state, the melting temperature of the water-soluble polymer must be 50 ° C. or higher. When the melting temperature is lower than 50 ° C., if the recorded paper or the like is left in a stacked state for a long period of time, the dye or pigment is adsorbed and the paper or the like becomes dirty, and the recording cannot be held in a stable state.

The dye used in the present invention may be a water-soluble dye or a hydrophobic dye, but is preferably an aqueous dye. The average particle size of the pigment is desirably 0.3 μm or less.

The dyes used in the present invention include C.I. I. Acid Yellow 19, C.I.
I. Acid Yellow 29, C.I. I. Aci
d Yellow 38 and the like. I. A
cid Red 37, C.I. I. Acid Red 1
18, C.I. I. Acid Red 158 and the like in the cyan series. I. Acid Blue 23, C.I. I. A
cid Blue 43, C.I. I. Acid Blue
127 and the like in the black system. I. Acid Blac
k1, C.I. I. Acid Black 24,
C. I. And water-soluble dyes such as AcidBlack 31. As the hydrophobic dye, C.I.
I. Disperse Yellow 36, C.I. I.
Disperse Yellow 42, and C.I. I. Disperse Red 35, C.I. I.
Disperse Red 87, and C.I.
I. Disperse Blue 6, C.I. I. Dis
perse Blue 35, and C.I. I.
Disperse Black 25, C.I. I. Dis
Perse Black 34 and the like.

The pigments used in the present invention include, for example, benzidine yellow G and faast yellow G in yellow system.
Organic pigments such as quinacridone magenta and naphthol cumin FBB for the magenta type, copper phthalocyanine and alkali blue G for the cyan type, and carbon black and aniline black for the black type. Examples of inorganic pigments include graphite 10G, titanium yellow, cadmium yellow, red bengal, molybdate orange, red lead, navy blue, cobalt blue, ultramarine, iron black, and the like.

[0017]

EXAMPLES Hereinafter, the recording liquid of the present invention will be described in more detail based on examples. However, the present invention is not limited to the examples. In the following examples, parts represent parts by weight.

Example 1 A mixed solution of 5 parts of carbon black (average particle size: 0.3 μm), 3 parts of polyvinylpyrrolidone (melting temperature: 70 ° C.), 10 parts of diethylene glycol, and 90 parts of water was mixed with a planetary ball mill. The suspension was ground and dispersed for 60 minutes to prepare a black suspension (viscosity at 25 ° C: 2.7 cp). The suspension 85 parts of the emulsion (a copolymer of acetic acid vinyl and ethylene, the melting temperature of 60 ° C, average particle size 0.5 [mu] m,) and the recording liquid was prepared by mixing 15 parts.

The recording liquid was mounted on an ink jet head and recording was performed on several types of plain paper. The drying speed of the recorded matter was very fast, and the peripheral shape of the recorded matter was smooth and no bleeding or feathering was observed. In addition, the recorded matter on several types of plain paper was extremely excellent in light resistance and water resistance, had a clear color tone, and had a high reflection density. Further, 50 g of weight was placed on the plain paper on which the recording was performed, and the paper was peeled off after 24 hours. Adsorption of the pigment between the papers was not recognized. In addition, this recording liquid was stable with no aggregation or sedimentation of the pigment, even after long-term storage.

Example 2 A mixture of 5 parts of copper phthalocyanine (average particle size: 0.2 μm), 3 parts of polyvinyloxazolidone (melting temperature: 80 ° C.), 10 parts of glycerin, and 90 parts of water was ground by a planetary ball mill for 60 minutes. Dispersion to prepare a cyan suspension (25
Viscosity at 300C). The suspension 85 parts of the emulsion was (copolymer of acetic acid vinyl and ethylene, the melting temperature 65 ° C, average particle size 0.3 [mu] m) recording liquid by mixing 15 parts was prepared. When recording was performed using this recording liquid in the same manner as in Example 1, excellent results were obtained as in Example 1, and the recording liquid was stable for a long time.

EXAMPLE 3 A mixture of 5 parts of quinacridone (average particle size: 0.3 μm), 5 parts of polyvinylpyrrolidone (melting temperature: 70 ° C.), 10 parts of propylene glycol, and 90 parts of water was mixed with a planetary ball mill for 60 hours.
The mixture was pulverized and dispersed for 1 minute to prepare a magenta suspension (viscosity 2.5 cp at 25 ° C.). The suspension 85 parts of the emulsion was (copolymer of acetic acid vinyl and ethylene, the melting temperature of 55 ° C, average particle size 0.7 [mu] m) recording liquid by mixing 15 parts was prepared. When recording was performed using this recording liquid in the same manner as in Example 1, excellent results were obtained as in Example 1, and the recording liquid was stable for a long time.

Example 4 A mixed solution of 5 parts of benzidine yellow (average particle size: 0.1 μm), 5 parts of polyvinyl acrylic acid (melting temperature: 75 ° C.), 10 parts of tripropylene glycol, and 90 parts of water was mixed with a planetary ball.
The mixture was pulverized and dispersed for 60 minutes using a mil mill to prepare a yellow suspension (viscosity at 25 ° C: 3.5 cp). This suspension 8
5 parts of the emulsion was (copolymer of acetic acid vinyl and ethylene, the melting temperature of 60 ° C, average particle size 0.5 [mu] m) recording liquid by mixing 15 parts was prepared. When recording was performed using this recording liquid in the same manner as in Example 1, excellent results were obtained as in Example 1, and the recording liquid was stable for a long time.

Embodiment 5 C.I. I. A mixed solution of 5 parts of Acid Black 24, 10 parts of diethylene glycol, 3 parts of polyvinylpyrrolidone (melting temperature 70 ° C.), and 87 parts of water was prepared into a black solution using an ultrasonic stirrer (viscosity at 25 ° C.). 2.
1 cp). The solution 85 parts of emulsion, 15 parts (a copolymer of acetic acid vinyl and ethylene, the melting temperature 65 ° C, average particle size 0.3 [mu] m) to prepare a recording liquid by mixing.

The recording liquid was mounted on an ink jet head, and recording was performed on several types of plain paper. The peripheral shape of the recorded matter was smooth and no bleeding or feathering was observed. The recorded matter on several types of plain paper was extremely excellent in water resistance, had a clear color tone, and had a high reflection density. Further, this recording liquid was stable even after long-term storage.

Example 6 C.I. I. A mixed solution of 5 parts of Acid Yellow 19, 10 parts of glycerin, 3 parts of polyacrylic acid (melting temperature 70 ° C.) and 87 parts of water was prepared into a yellow solution using an ultrasonic stirrer (viscosity 2 at 25 ° C.). .4 cp).
The solution 85 parts of emulsion, 15 parts (a copolymer of acetic acid vinyl and ethylene, the melting temperature 65 ° C, average particle size 0.3
μm) was mixed to prepare a recording solution. Recording was performed in the same manner as in Example 5 using this recording liquid.
Excellent results were obtained in the same manner as described above, and the recording liquid was stable for a long time.

Embodiment 7 C.I. I. 5 parts of Acid Red 37, 10 parts of ethylene glycol, 3 parts of polyoxazolidone (melting temperature 80
ΔC) A mixed solution of 87 parts of water was prepared into a magenta solution using an ultrasonic stirrer (viscosity at 25 ° C. 1.9).
cp). The solution 85 parts of emulsion, 15 parts (a copolymer of acetic acid vinyl and ethylene, the melting temperature 65 ° C, average particle size 0.3 [mu] m) to prepare a recording liquid by mixing. When recording was performed in the same manner as in Example 5 using this recording liquid,
Excellent results were obtained as in Example 5, and the recording liquid was stable for a long time.

Embodiment 8 C.I. I. A mixture of 5 parts of Acid Blue 23, 10 parts of propylene glycol, 3 parts of polyethylene oxide (melting temperature 70 ° C.) and 87 parts of water was prepared into a cyan solution using an ultrasonic stirrer (25 ° C.). At 1.9 cp). 85 parts of this solution and 15 parts of emulsion
(A copolymer of acetic acid vinyl and ethylene, the melting temperature 65 ° C, average particle size 0.3 [mu] m) to prepare a recording liquid by mixing. When recording was performed using this recording liquid in the same manner as in Example 5, excellent results were obtained as in Example 5, and the recording liquid was stable for a long time.

Comparative Example 1 A mixed solution of 5 parts of carbon black (average particle diameter: 0.3 μm), 3 parts of polyvinylpyrrolidone (melt viscosity: 70 ° C.), 10 parts of diethylene glycol and 90 parts of water was subjected to a planetary ball mill. To obtain a black recording liquid (25 ° C.
2.7 cp). When printing was performed using this recording liquid in the same manner as in Example 1, the recorded matter was inferior in water resistance. In particular, when a wet friction test was performed, bleeding occurred in the recorded matter. When left at room temperature, sedimentation of the pigment occurred within several hours.

Comparative Example 2 A mixed solution of 5 parts of carbon black (average particle size: 0.3 μm), 3 parts of polyvinylpyrrolidone (melting temperature: 70 ° C.), 10 parts of diethylene glycol, and 90 parts of water was mixed with a planetary ball mill. The suspension was ground and dispersed for 60 minutes to obtain a black suspension (25 ° C.
2.7 cp). The suspension 85 parts of the emulsion (a copolymer of acetic acid vinyl and ethylene, the melting temperature 6
(0 ° C., average particle size 0.1 μm) was mixed to prepare a recording liquid. However, this recording liquid was separated when left at room temperature for 5 hours, and a stable state as a recording liquid could not be maintained.

Comparative Example 3 A mixed solution of 5 parts of carbon black (average particle size: 0.3 μm), 3 parts of polyvinylpyrrolidone (melting temperature: 70 ° C.), 10 parts of diethylene glycol, and 90 parts of water was mixed with a planetary ball mill. The suspension was ground and dispersed for 60 minutes to obtain a black suspension (25 ° C.
(Viscosity 2.7 CP). The suspension 85 parts of the emulsion (a copolymer of acetic acid vinyl and ethylene, the melting temperature 6
A recording solution was prepared by mixing 15 parts (0 ° C., average particle size 5.0 μm). When recording was performed in the same manner as in Example 1 using this recording liquid, the obtained recorded matter had insufficient water resistance. In particular, when a wet friction test was carried out, bleeding occurred in the recorded matter.

Comparative Example 4 A mixed solution of 5 parts of carbon black (average particle size: 0.3 μm), 3 parts of polyvinylpyrrolidone (melting temperature: 35 ° C.), 10 parts of diethylene glycol, and 90 parts of water was subjected to a planetary ball mill. To obtain a black recording liquid (25 ° C.
At 2.3 cp). When recording was performed in the same manner as in Example 1 using this recording liquid, the recorded matter was inferior in water resistance. In particular, when a wet friction test was performed, the recorded matter was blurred. Further, 50 g of weight was placed on the plain paper on which the recording was performed, and the paper was peeled off after 24 hours. When the paper was peeled off, the pigment was adsorbed between the papers and the paper could not be easily peeled off.

Comparative Example 5 C.I. I. A mixed solution of 5 parts of Acid Black 24, 10 parts of diethylene glycol, and 90 parts of water was prepared into a black recording liquid using an ultrasonic stirrer (viscosity of 25.degree.
1 cp). When recording was performed in the same manner as in Example 1 using this recording liquid, bleeding occurred in the print when a water resistance test, particularly a wet friction test, was performed.

[0033]

Thus, the recording liquid of the present invention is excellent in the coating properties of dyes or pigments and the storage stability. Further, it is possible to obtain a recorded matter having a clear color tone and a high reflection density, and the recorded matter is excellent in water resistance and light resistance.

Claims (2)

(57) [Claims] 1. An emulsion mainly composed of a non-crosslinked vinyl polymer having a melting temperature of 50 ° C. or higher and having an average particle size of 0.2 μm to 2.0 μm, and a water-soluble emulsion having a melting temperature of 50 ° C. or higher. A recording liquid comprising a polymer, a dye or a pigment, and water. 2. The recording liquid according to claim 1, wherein the average particle size of the pigment is 0.3 μm or less.