JPH09176532A - Oily black ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the above composition which has a color tone near to the real black and excellent water resistance, long-term storage stability and the light exposure resistance of images printed therewith, and useful for ink jet printers of hot melt type, etc., by adding a specific colorant to a vehicle that is liquid or solid at room temperature. SOLUTION: This composition comprises (A) a vehicle that is liquid or solid at room temperature, and a colorant composed of (B) a compound (B1 ) of formula 1 [X and Y are each H, a 1-4C alkyl, 1-4C alkoxy, halogen, nitro, or cyano; Z<1> and W<1> are each H, a 1-4C alkyl, 1-4C alkoxy, or 1-5C acylamino; R<1> and R<2> are each a 1-8C alkyl (substituted with a halogen, cyano, a 1-8C alkoxy, etc.), or H], and a compound (B2 ) of formula II [P is nitro or cyano; Q" and Q<2> are each a 1-4C alkyl or halogen; W<2> and Z<2> , are each H or Q<1> ; R<3> and R<4> are each a 1-8C alkyl (substituted with a halogen, cyano, a 1-8C alkoxy, etc.)] at a wt. ratio B<1> /B<2> of (90:10) to (60:40).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an oil-based black ink composition, and more particularly to an oil-based black ink composition for inkjet.

[0002]

2. Description of the Related Art Colorants for oil-based black inks for ink jet have hitherto been carbon black, nigrosine dyes, or C.I. I. Solvent Black
Have been used. However, with these colorants, the bluish color tone is strong, or the color is brown, it is difficult to obtain a true black color, or the light fastness is poor,
Due to insufficient dispersion or dissolution stability in the vehicle, when the ink is stored for a long period of time, it has a drawback that the colorant is discolored or discolored, or separated from oil.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an oily black ink composition having a true black color tone, good light resistance, and stable after long-term storage of the ink.

[0004]

The oily black ink composition of the present invention is a liquid or a solid at room temperature.
Particularly when used for inkjet, the ink is melted before being ejected. The present invention relates to an oily black ink composition containing a vehicle which is liquid or solid at room temperature and a colorant represented by the following general formulas [I] and [II].

[0005]

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(In the formula, X and Y each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group or a cyano group. Z ¹ and W ¹ is independently a hydrogen atom or 1 carbon atom
Represents an alkyl group having 4 to 4, an alkoxy group having 1 to 4 carbon atoms, or an acylamino group having 1 to 5 carbon atoms. R ¹ and R ²
Are each independently a halogen atom, a cyano group, or a carbon number of 1 to
It represents an alkoxy group having 8 carbon atoms, an alkoxyalkoxy group having 2 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms which may be substituted with an acyloxy group having 1 to 9 carbon atoms, or a hydrogen atom. )

[0007]

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(In the formula, P represents a nitro group or a cyano group, Q ¹ and Q ² each independently represent an alkyl group having 1 to 4 carbon atoms, or a halogen atom, and W ² and Z ² each independently. Represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a halogen atom, and R ³ and R ⁴ each independently represent a halogen atom, a cyano group, an alkoxy group having 1 to 8 carbon atoms, or an alkoxyalkoxy having 2 to 8 carbon atoms. Represents a group or an alkyl group having 1 to 8 carbon atoms which may be substituted with an acyloxy group having 2 to 8 carbon atoms.)

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail. The colorant used in the present invention is represented by the above general formulas [I] and [II], and each substituent has 1 carbon atom.
Examples of the alkyl group having 4 to 4 include a methyl group, an ethyl group, a linear or branched propyl group, and a butyl group. Examples of the alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, and a straight chain. Alternatively, a branched chain propoxy group and a butoxy group may be mentioned. Examples of the halogen atom include a chlorine atom and a bromine atom, and as the acylamino group having 1 to 5 carbon atoms, a formylamino group, or an acetylamino group, an alkylcarbonylamino group having 1 to 4 carbon atoms such as a propionylamino group. Examples of the alkoxy alkoxy group having 2 to 8 carbon atoms include those in which two molecules of the above alkoxy group are linked, for example, a methoxyethoxy group and an ethoxyethoxy group, and the acyloxy group having 1 to 9 carbon atoms includes formyloxy group. Group, an alkylcarbonyloxy group such as an acetyloxy group, and an arylcarbonyloxy group such as a benzoyloxy group and a toluyloxy group. Specific examples of these colorants include the following.

[0010]

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[0011]

[Chemical 6]

[0012]

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The vehicle is not particularly limited as long as it is a liquid or a solid at room temperature and melts by heating when it is a solid, and both dissolve the colorant and do not dissolve in water. Carnauba wax, paraffin wax, sazol wax, microcrystalline wax, waxes such as copolymers of long chain alkenes and unsaturated fatty acid anhydrides, stearic acid, higher fatty acids such as palmitic acid, stearic acid amide, Higher fatty acid amides such as palmitic acid amide and p-toluenesulfonic acid amide, α-methylnaphthalene, β-methylnaphthalene, alkylnaphthalene such as 2,6-dimethylnaphthalene, dibutylphthalate, dioctylphthalate, dibutyladipate, Dimethyl terephthalate, benzyl benzoe And esters such as naphthalene 2,6-dicarboxylic acid methyl ester, and phosphoric acid esters such as tributyl phosphate are used.

In the present invention, a vehicle to be used is one in which a vehicle having a relatively low melting point (softening point) (for example, 70 ° C. or lower) and a vehicle having a relatively high melting point (120 to 200 ° C.) are used in combination. It is preferable because there is no stain when the paper is rubbed with a finger or the like and color transfer when a plurality of recorded materials are stacked. These vehicles have a low melting point,
It is preferable that the melting point of the mixture is 100 ° C. or lower, preferably 80 ° C. or lower. The temperature range is set to prevent the colorant from deteriorating during mixing and dissolution.

The vehicle may contain a polyamide-based, polyurethane-based, polyester-based, epoxy-based or polyacrylic-based resin compatible with the vehicle in an amount of 0.5 to 20% by weight based on the total amount of the ink composition. . By using these resins together, the film strength of the ink can be further increased.

In the method for producing the ink composition of the present invention, when the liquid vehicle, or when the vehicle is solid or when the solid vehicle is used in combination, the colorant of the present invention is directly dissolved after being melted by heating. Examples of the method include producing an ink composition. Needless to say, when this ink composition is used for ink jet recording, if necessary, it is better to remove impurities and the like by heating and melting when the ink is solid and then passing the ink composition through a filter or the like. Yes.

The content of the colorant in the ink composition is in the range of 2 to 10% by weight, preferably 3 to 8% by weight. The mixing ratio of the colorants represented by [I] and [II] is [I] / [II] = 90/1 by weight.
It is in the range of 0 to 60/40, preferably 90/10 to 70/30. Since the colorants represented by the general formulas [I] and [II] have excellent solubility in a solid or liquid vehicle at room temperature as described above, an oily black ink composition having good storage stability is obtained. be able to. Further, since the oil-based black ink composition of the present application is also excellent in heat resistance,
It can be used as an ink composition of a so-called hot melt type (or wax jet type) inkjet recording device, which is ejected from a head of the inkjet recording device at a temperature higher than room temperature. Further, by coating or impregnating a substrate such as a cloth or a plastic film with the ink composition of the present application, it can be used as an ink sheet for melt type thermal transfer.

[0018]

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

The mixture having the above composition was stirred at 60 ° C. for 5 hours, and the colorant was dissolved in the vehicle of 1-methylnaphthalene or 2,6-dimethylnaphthalene to prepare an ink composition. This is a hot melt inkjet printer JOL
Printing was performed on electrophotographic paper (product of Xerox Co.) using T SJ01A PS2 (trade name, product of Hitachi Koki Co., Ltd.). The printed matter has no bleeding and is a slightly bluish black print. Even if the image is rubbed by hand 10 seconds after recording,
No stain was found around the image and on the hands. Also, using a xenon fade meter (product of Suga Test Instruments Co., Ltd.), 100
After irradiation for a long time, the discoloration of the image was small. Further, the colorant was not separated even after the ink composition was stored at 60 ° C. for 3 months.

Embodiment 2 Ink was formed and evaluated in the same manner as in Example 1 except that the mixture having the above composition was used. Good results were obtained as in Example 1.

Example 3 Ink was formed and evaluated in the same manner as in Example 1 except that the mixture having the above composition was used. Good results were obtained as in Example 1.

Example 4 Ink was formed and evaluated in the same manner as in Example 1 except that the mixture having the above composition was used. Good results were obtained as in Example 1.

Examples 5 to 8 Nos. I-2 and No. Instead of the dye of II-2, No. I-4 and No. II-3, N
o. I-5 and No. 1 II-4, No. I-6 and No.
II-1, No. I-7 and No. An ink was formed and evaluated in the same manner as in Example 2 except that the dye of II-1 was used. Good results were obtained as in Example 2.

[0024]

The oil-based black ink composition of the present invention has not only water resistance but also a preferable color tone close to true black,
It has excellent light resistance of images and long-term storage (storage) stability of ink, and is favorably used as an ink for forming a color material layer of a hot-melt type ink composition or a melt transfer type thermal transfer ink sheet. .

Claims (3)

[Claims] 1. An oily black ink composition comprising a vehicle which is liquid or solid at room temperature and a colorant represented by the following general formulas [I] and [II]. Embedded image (In the formula, X and Y are independently a hydrogen atom and a carbon number of 1
Represents an alkyl group having 4 to 4, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a nitro group, or a cyano group. Z ¹ and W ¹ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or 1 to 5 carbon atoms.
Represents an acylamino group. R ¹ and R ² are each independently a carbon which may be substituted with a halogen atom, a cyano group, an alkoxy group having 1 to 8 carbon atoms, an alkoxyalkoxy group having 2 to 8 carbon atoms, or an acyloxy group having 1 to 9 carbon atoms. It represents an alkyl group of the numbers 1 to 8 or a hydrogen atom. ) (In the formula, P represents a nitro group or a cyano group, Q ¹ and Q ² each independently represent an alkyl group having 1 to 4 carbon atoms, or a halogen atom, and W ² and Z ² each independently represent a hydrogen atom, Represents an alkyl group having 1 to 4 carbon atoms or a halogen atom, and R ³ and R ⁴ are each independently a halogen atom, a cyano group, an alkoxy group having 1 to 8 carbon atoms, or 2 carbon atoms.
To an alkoxyalkoxy group having 8 to 8 or an alkyl group having 1 to 8 carbons which may be substituted with an acyloxy group having 2 to 8 carbons. ) 2. The weight ratio of the colorants represented by the general formulas [I] and [II] is [I] / [II] = 90 /
The oil-based black ink composition according to claim 1, which is in a range of 10 to 60/40. 3. The oily black ink composition according to claim 1, which is ejected from a head of an ink jet recording apparatus at a temperature higher than room temperature.