JPH09169936A - Ink composition for hot-melt inkjet - Google Patents

Abstract

(57) Abstract: A hot-melt type ink jet ink composition having a clear and pure black color is provided. SOLUTION: Black dye 100 parts by weight, yellow dye 10-10
A hot-melt ink composition for ink jet, comprising 0.1 to 15% by weight of a coloring material composed of 30 parts by weight and 5 to 20 parts by weight of a red dye.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a hot-melt ink jet ink composition.

[0002]

2. Description of the Related Art As an ink jet recording system, there are, for example, an electric field control system for discharging ink using electrostatic attraction; a drop-on-demand system (pressure pulse system) for discharging ink using vibration pressure of a piezo element. Various methods, such as a thermal ink jet method, in which ink is ejected by utilizing pressure generated by forming and growing bubbles by high heat, and the like, can be used to obtain extremely high-resolution printed images.

In these ink jet recording systems, an aqueous ink using water as a main solvent and an oil ink using an organic solvent as a main solvent are generally used. Printed images obtained using water-based inks generally have poor water resistance, whereas using oil-based inks can provide printed images having excellent water resistance. However, since these water-based inks and oil-based inks are liquids at room temperature, they have a drawback that when they are printed on a recording paper, bleeding tends to occur and sufficient print density cannot be obtained. In addition, since the liquid is used, a precipitate is easily generated from the ink, which causes the reliability of the ink jet recording system to be greatly reduced.

In order to improve these drawbacks of conventional inks which are liquid at room temperature, hot melt type oil-based ink compositions which are solid at room temperature have been proposed. US Patent No. 36
No. 5,393,2 discloses an ink containing a dialkyl sebacate ester and is disclosed in US Pat.
No. 90369 and JP-A-58-108271 disclose inks containing natural wax, and JP-A-59-22973 discloses inks containing stearic acid. , JP-A-61-83
Japanese Patent No. 268 discloses an ink containing an acid or alcohol having 20 to 24 carbon atoms and a ketone having a relatively high melting point. Japanese Patent Laid-Open No. 62-48774 discloses a high hydroxyl value. An ink containing a thermosetting resin having a melting point, a solid organic solvent having a melting point higher than 150 ° C., and a small amount of a dye substance is disclosed.
No. 27, a coloring material, a first solvent which is solid at room temperature and liquefies when heated to a temperature higher than room temperature, and a second solvent which dissolves the first solvent and has high volatility of the liquid at room temperature. An ink consisting of
Japanese Patent No. 3 discloses an ink containing a synthetic wax having a polar group and a dye soluble in the wax.

Among such ink compositions which are solid at room temperature, as a black ink, Japanese Patent Publication No. 153773/1990 discloses a coloring material composed of an oil-soluble black dye and an oil-soluble yellow dye in an amount of 1.0 to 10. An ink composition containing 10.0 wt% is disclosed.

[0006]

However, such a black ink composition has a problem that when it is printed on a recording paper, it does not become pure black but becomes a bluish color.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a hot-melt type ink composition for ink jet which exhibits a clear and pure black color.

[0008]

[Means for Solving the Problems] The above object is to achieve a black dye 1.
0.1 to 15% by weight of a coloring material composed of 00 parts by weight, 10 to 30 parts by weight of a yellow dye, and 5 to 20 parts by weight of a red dye.
It can be achieved by a hot melt type ink jet ink composition containing the same. Hereinafter, the present invention will be described in detail.

The coloring material used in the present invention is a black dye 10
0 parts by weight, 10 to 30 parts by weight of yellow dye, and 5 to 20 parts by weight of red dye. The amount of the yellow dye compounded is 10 to 3 with respect to 100 parts by weight of the black dye.
0 parts by weight. Even if the amount is less than 10 parts by weight or exceeds 30 parts by weight, a clear and pure black color cannot be obtained, and thus the content is limited to the above range. The amount of the red dye compounded is 5 to 20 parts by weight based on 100 parts by weight of the black dye. If the amount is less than 5 parts by weight or more than 20 parts by weight, a clear and pure black color cannot be obtained, and thus the content is limited to the above range.

The content of the above-mentioned coloring material is 0.1 to the hot-melt ink jet ink composition obtained.
15% by weight. If it is less than 0.1% by weight, a printed image of a sufficient density cannot be obtained, and if it exceeds 15% by weight, the balance with other compositions becomes poor, and the dye is sufficiently dissolved in the ink composition. Since it cannot be performed, it is limited to the above range. It is preferably 0.5 to 8% by weight, and more preferably 0.7 to 5% by weight.

The black dye, the yellow dye and the red dye constituting the color material are not particularly limited as long as they are dyes generally used in oil-based inks. Examples of the dyes include azo dyes, disazo dyes, metal complex salt dyes, naphthol dyes, anthraquinone dyes, indigo dyes, carbonium dyes, quinone imine dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes,
Examples thereof include oil-soluble dyes such as naphthoquinone dyes, xanthene dyes, phthalocyanine dyes, and metal phthalocyanine dyes. Each of these dyes may be used alone or in combination of two or more.

In the present invention, the black dye is
Color Index Number Solvent Black 29
(Hereinafter, referred to as “CI Solvent Black 29”.) As the above-mentioned yellow dye, Color Index Number Solvent Yellow 162 (hereinafter,
It is called "CI Solvent Yellow 162". ) Is preferable, and as the red dye, Color Index Number Solvent Red 27 (hereinafter, referred to as “CI Solvent Red 27”) is preferable. The hot-melt ink jet ink composition of the present invention contains the above-mentioned C.I. I. Solvent Black 29, C.I. I. Solvent Yellow 162, and C.I. I. By using Solvent Red 27, a more ideal black hue can be exhibited.

The hue of the hot-melt ink jet ink composition of the present invention can be evaluated by using the L ^* a ^* b ^* color system. The outline of the L ^* a ^* b ^* color system is as follows. The color is measured by measuring the intensity of light reflected or transmitted from an object by applying the photoelectric principle, and the color is displayed by three numerical values as a value calculated by a predetermined method. The L ^* a ^* b ^* color system is one of them, and the value of L ^* is called the lightness index and the value of a ^* b ^* is called the chromaticness index. These three numerical values L ^* , a ^* , and b ^* are , The position of the point in the spatial coordinates is represented as shown in FIG. For example, (L ^* ,
a ^* , b ^* ) = (73.5,17.3,31.4) is a bright light color, (42.83,45.06)
The color indicated by 9.52) is red.

FIG. 2 shows the correspondence between a ^* b ^* and hue and saturation. In the figure, R means red, B means blue, and G means green. As can be seen from FIGS. 1 and 2, L ^* = 0, a ^*
It can be said that the closer to = 0 and b ^* = 0, the more true black.

The hot melt ink jet ink composition of the present invention may contain a wax having a melting point of 50 to 150 ° C. and a resin. The wax can be the main material of the hot melt type ink, and can determine the characteristics of the hot melt type ink such as thermal characteristics and viscosity. The melting point of the above wax is 50 to 150.
C is preferred. If it is less than 50 ° C or exceeds 150 ° C, it is not practical.

The wax is not particularly limited as long as it is stable to heat, and examples thereof include petroleum waxes such as paraffin wax and microcrystalline wax; candelilla wax, carnauba wax, rice wax, jojoba solid wax. Plant waxes such as; waxes such as beeswax, lanolin and whale wax; mineral waxes such as montan wax; synthetic hydrocarbons such as Fischer-Tropsch wax and polyethylene wax; hydrogenation of hydrogenated castor oil, hydrogenated castor oil derivatives, etc. wax;
Montan wax derivative, paraffin wax derivative,
Modified waxes such as microcrystalline wax derivatives and polyethylene wax derivatives; higher fatty acids such as behenic acid, stearic acid, palmitic acid, myristic acid and lauric acid; higher alcohols such as stearyl alcohol and behenyl alcohol; 12-hydroxystearic acid, 1
Hydroxystearic acid such as 2-hydroxystearic acid derivative; ketone such as stearone, lauron; lauric acid amide, stearic acid amide, oleic acid amide, erucic acid amide, ricinoleic acid amide, 12-hydroxystearic acid amide, special fatty acid amide, Fatty acid amides such as N-substituted fatty acid amides; amines such as dodecylamine, tetradecylamine, octadecylamine; methyl stearate, octadecyl stearate, glycerin fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, ethylene glycol fatty acid ester, poly Examples thereof include esters such as oxyethylene fatty acid esters; polymerization waxes such as α-olefin maleic anhydride copolymer waxes. These may be used alone or in combination of two or more.

The content of the above wax is 30 with respect to the obtained hot melt type ink jet ink composition.
~ 90% by weight is preferred. If it is less than 30% by weight, the basic characteristics of the hot-melt ink composition such as sharp melt and drying speed cannot be realized, and if it exceeds 90% by weight, the transparency of the ink composition and the effect on paper are improved. Fixing property of is deteriorated.

The resin used in the present invention functions to impart adhesiveness to recording paper, control the viscosity of the ink composition, hinder crystallization of wax, impart transparency of the ink composition, and the like.

The above resin is preferably an oil-soluble resin. The oil-soluble resin is not particularly limited, for example,
Olefin resins such as polyethylene resin, polypropylene resin, polyisobutylene resin; vinyl resins such as ethylene-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate copolymer resin, vinyl acetate resin, ethylene-vinyl chloride-vinyl acetate copolymer resin Resin: Acrylic resin such as methacrylic acid ester resin, polyacrylic acid ester resin, ethylene-ethyl acrylate copolymer resin, ethylene-methacrylic acid copolymer resin; phenol resin; polyurethane resin; polyamide resin; polyester resin; ketone resin;
Alkyd resin; rosin resin; hydrogenated rosin resin; petroleum resin; hydrogenated petroleum resin; maleic acid resin; butyral resin; terpene resin; hydrogenated terpene resin; coumarone-indene resin and the like. These may be used alone or in combination of two or more.

The content of the above resin is 5 to 70 with respect to the obtained hot melt type ink jet ink composition.
% By weight is preferred. If it is less than 5% by weight, the transparency of the ink composition and the fixing property to paper are deteriorated, and if it exceeds 70% by weight, the basic characteristics of the hot-melt ink composition such as sharp melt and drying are not improved. Speed cannot be realized.

The above resin has a weight average molecular weight of 500 to 500,000, which is separated by gel permeation chromatography using a differential refractometer as a detector or temperature-rising gas chromatography using a thermal conductivity detector as a detector. Those are preferable.
When it is less than 500, the softening point of the resin is low, and when it is made into an ink, the printed matter does not solidify. When it exceeds 500,000, it cannot be easily melted, and when it is made into an ink, up to a temperature at which printing is possible. It is almost impossible to raise the operating temperature of the recording device. More preferably, it is 600 to 400,000,
More preferably, it is 700 to 300,000.

The hot melt ink jet ink composition of the present invention can be obtained, for example, by the following method. The wax and resin are heated and melted at a temperature of 70 to 250 ° C., preferably 100 to 200 ° C., and a black dye, a yellow dye and a red dye are added and mixed. Using a stirrer such as a dissolver, 200 to 10,000
Stir and mix at rpm, preferably 500-5000 rpm. The obtained ink composition is filtered using a mesh filter or the like to finally obtain a hot melt type ink composition for inkjet.

[0023]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 As an oil-soluble black dye, C.I. I. Solvent black 2
9 (ORASOL Black RL, manufactured by Ciba-Geigy Co., Ltd.), as a red dye, C.I. I. Solvent Red 27 (FAT-RED 5B02, manufactured by Hoechst), a yellow dye such as C.I. I. Solvent Yellow 1
62 (Neopen Yellow 075, BASF
Room temperature solid wax as a vehicle,
Paraffin wax (paraffin wax standard product 15
5, manufactured by Nippon Seiro Co., Ltd., and an ethylene-vinyl acetate copolymer (Evaflex 210, manufactured by Mitsui Polychemical Co., Ltd.) was used as the resin.

Ink formulation Paraffin wax standard 155 85% by weight Evaflex 210 12% by weight ORASOL Black RL 2.25% by weight FAT-RED 5B02 0.25% by weight Neopen Yellow 075 0.5% by weight

Paraffin wax standard product 155 and Evaflex 210 are heated and melted at a temperature of 140 ° C., and OR
ASOL Black RL, FAT-RED 5B0
2, Neopen Yellow 075 was mixed.
This was stirred and mixed at 1000 rpm with a dissolver. The prepared ink composition was filtered with a heating filter manufactured by Toyo Roshi Kaisha, Ltd. using a 2 μm mesh filter to obtain a final ink composition. When the above ink composition was mounted on a hot melt type ink jet recording apparatus and printing was performed, dark black beautiful printing could be performed.

Example 2 As an oil-soluble black dye, C.I. I. Solvent black 2
9 (ORASOL Black RLI, manufactured by Ciba-Geigy Co., Ltd.), a red dye such as C.I. I. Solvent Red 27 (FAT-RED 5B02, manufactured by Hoechst), a yellow dye such as C.I. I. Solvent Yellow 1
62 (Neopen Yellow 075, manufactured by BASF), and a room temperature solid wax as a vehicle is Microcrystalline Wax (Hi-Mic 2065,
As a resin, hydrogenated petroleum resin (Alcon P-90, manufactured by Arakawa Chemical Industry Co., Ltd.) was used.

Ink formulation Hi-Mic 2065 45 wt% Alcon P-90 52 wt% ORASOL Black RLI 2.35 wt% FAT-RED 5B02 0.25 wt% Neopen Yellow 075 0.4 wt%

In the same manner as in Example 1, Hi-Mic 20
65, Alcon P-90 was dissolved by heating at a temperature of 140 ° C., and ORASOL BLACK RLI, FAT-RE
D5B02 and Neopen Yellow 075 were mixed. This was stirred and mixed at 1000 rpm with a dissolver. The adjusted ink composition manufactured by Toyo Roshi Kaisha,
Filtration was performed using a 2 μm mesh filter with a heating filtration device to obtain a final ink composition. When the above ink composition was mounted on a hot melt type ink jet recording apparatus and printing was performed, good fixability was exhibited. Also, a high OD value was obtained on the recording paper.

Comparative Example 1 Ink Formulation Paraffin Wax Standard 155 88 wt% Evaflex 210 10 wt% ORASOL Black RL 3 wt%

Paraffin wax standard product 155 and Evaflex 210 are heated and melted at a temperature of 140 ° C., and OR
ASOL Black RL was mixed. This was stirred and mixed at 1000 rpm with a dissolver. The prepared ink composition was applied to a heating filter device manufactured by Toyo Roshi Kaisha Ltd. 2
Filtration was carried out using a μm mesh filter to obtain a final ink composition. The ink composition is mounted on a hot-melt type inkjet recording device for printing, and the color of the printed matter is measured by Suga Test Instruments Co., Ltd., multi-source spectrophotometer MS
It was carried out by C-2 type. Comparing this result with the results of Example 1, a ^* in 5, b ^* in confirmed differences of as 20 values, it was bluish printing color.

Comparative Example 2 Ink Formulation Hi-Mic 2065 45% by weight Alcon P-90 53% by weight ORASOL Black RLI 2% by weight Neopen Yellow 075 0.5% by weight

Hi-Mic 2065, Archon P-90
Is melted by heating at a temperature of 140 ° C., and ORASOL Bl
ack RLI, Neopen Yellow 075
Was mixed. 1000 rpm with a dissolver
And mixed with stirring. The prepared ink composition was filtered with a heating filter manufactured by Toyo Roshi Kaisha, Ltd. using a 2 μm mesh filter to obtain a final ink composition. The above ink composition was mounted on a hot-melt type ink jet recording apparatus to perform printing, and the color of the printed matter was measured with a multi-source spectrophotometer MSC-2 type manufactured by Suga Test Instruments Co., Ltd. Comparing this result with the results of Example 2, a ^* in 1, b ^* in confirmed differences of as 20 values, it was bluish printing color.

[0034]

Since the hot-melt ink jet ink composition of the present invention has the above-mentioned constitution, it can show a clear and pure black color and can be suitably used for an ink jet recording apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram showing a color space and color coordinates of an L ^* a ^* b ^* color system in an example of the present invention.

FIG. 2 is a ^* , b ^* values and hues according to an embodiment of the present invention,
It is a figure showing the correspondence of saturation.

Claims (4)

[Claims] 1. 100 parts by weight of a black dye and 10 to 10 of a yellow dye.
A hot-melt ink-jet ink composition comprising 0.1 to 15% by weight of a coloring material comprising 30 parts by weight and 5 to 20 parts by weight of a red dye. 2. The hot-melt ink-jet ink composition according to claim 1, comprising a coloring material, a wax having a melting point of 50 to 150 ° C., and a resin. 3. The hot melt inkjet ink composition according to claim 2, wherein the resin has a weight average molecular weight of 500 to 500,000. 4. The black dye is color index number / solvent black 29, the yellow dye is color index number / solvent yellow 162, and the red dye is color index number / solvent red 27. The hot-melt ink jet ink composition according to 2 or 3.