JP2005179656A - Aqueous ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous ink capable of improving fastness of a picture image, for example, formed out of an ink for which an anionic group-containing dye, especially a water-soluble phthalocyanine dye and/or porphyrin dye, is used, by a simple procedure, without deteriorating characteristics, such as viscosity and transparency, as the ink, nor color development of the picture image. <P>SOLUTION: This aqueous ink contains at least a dye and an onium cation compound, wherein the onium cation compound has an amide bond. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a water-based ink capable of forming an image having excellent fastness.

  Currently, a wide variety of coloring materials and coloring agents are used, and among them, powdering and water-based methods are actively performed from the viewpoint of environmental problems. Examples of fields in which color materials are used include paints, pens and markers, printer inks, and cosmetics. Among printers, inkjet printers are used in various ways, such as industrial and general household page printers, circuit board wiring, liquid crystal, and EL element patterning. Dyes and pigments are used for the liquid used for the ink jet printer, that is, the color material used as an ink component.

  An image created by an ink jet method using an ink using a dye as a coloring material has a feature that the chroma is higher than an image formed using an ink using a pigment as a coloring material. There is also a disadvantage that it is inferior in fastness such as light resistance.

  Examples of the fastness required for an image include water resistance, light resistance, and gas resistance. These fastnesses are different depending on the molecular structure of the dye used in the ink. For example, an image composed of an azo dye generally shows a relatively high fastness against gas deterioration such as ozone, but tends to be low in light fastness. In addition, an image made of a phthalocyanine dye has a low fastness to gas deterioration such as ozone, but tends to have a high fastness to light.

  Many research examples have been seen so far in order to improve the fastness of the image composed of the above dye. There are various methods such as a method of introducing a resin component into the ink and a method of adding a deterioration inhibitor. Examples of a method for introducing a resin component into the ink include a method in which a dye and a resin are mixed and contained, a method in which a dye is included (encapsulated) with a resin, and the like. However, when the resin component is introduced into the ink, for example, the resin dissolves in the ink solvent to form a solution, and the viscosity of the ink increases, or the resin in the solution denatures when heated. May occur.

  On the other hand, when the dye is included and contained in the resin, there is a concern about the same problem as described above. In addition, for example, assuming dye-containing resin fine particles, the presence form and content of the dye, or the mutual relationship between the dye and the resin It is necessary to consider the action, and very high technology is required. The same applies to the case where a deterioration inhibitor is added to the ink containing the dye.

  As for the types and characteristics of the color materials used in the ink, as described above, the phthalocyanine and porphyrin dyes give an image having very high fastness to light, but against an oxidizing gas such as ozone. Currently, the image has low robustness (see Patent Documents 1 to 4). There are also research examples to improve fastness to gases such as ozone, for example, a proposal for controlling the orientation of functional groups when synthesizing phthalocyanine and porphyrin (see Patent Document 5), or water solubility. There is a proposal such as amidation of a functional group for imparting (see Patent Document 6). These are all useful techniques, but these phthalocyanine and porphyrin derivatives are difficult to synthesize, and the cost increases, or the solubility of the derivatives in water changes and the affinity for water decreases. On the other hand, there is a side.

JP 2002-105349 A Japanese Patent No. 2534892 JP 2002-256182 A Japanese Patent No. 2905274 JP 2002-285050 A Japanese Patent Laid-Open No. 2002-249677

  Accordingly, an object of the present invention is to improve the fastness of an image formed by an ink using, for example, a dye having an anionic group, in particular, a water-soluble phthalocyanine dye and / or a porphyrin dye, and an ink such as viscosity and transparency. It is an object of the present invention to provide a water-based ink that can be improved by a simple method without impairing the characteristics and color development of an image.

  The above object is achieved by the present invention described below. That is, the present invention is an aqueous ink containing at least a dye and an onium cation compound, and the onium cation compound has an amide bond. As a particularly preferred embodiment, the above dye is a dye having an anionic group, and the ratio of [onium cation equivalent / anion equivalent] of the onium cation compound and the dye having the anionic group is 0.01 to 2. Ink.

  As a result of intensive studies in order to solve the above-described problems of the prior art, the present inventors have prepared, for example, dyes having an anionic group widely used in inks, particularly phthalocyanine dyes and In the ink, a water-soluble compound having a basic group or a cationic group having opposite ionicity with respect to an acidic group or an anionic group that ensures water-solubility in the porphyrin dye coexists in the ink. The present invention has been found by finding that it is possible to provide an ink that can form an image with high fastness while ensuring the stability of the color material therein. That is, according to the present invention, by containing an onium cation compound in an ink, for example, in an aqueous ink using a dye having an anionic group, in particular, a water-soluble phthalocyanine dye and / or a porphyrin dye, the ink Can improve the robustness of the image formed by a simple method.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. The aqueous ink of the present invention contains at least a dye and an onium cation compound, and the onium cation compound has an amide bond.

The dye used in the present invention is not particularly limited, and any conventionally known dye having an anionic group widely used in ink jet recording inks, for example, a direct dye, an acid dye, etc. Can also be used. As a form in which the effect obtained by the present invention is more remarkable, for example, a water-soluble phthalocyanine compound and / or a water-soluble porphyrin compound represented by the following general formula (I) is used as a dye contained in the ink. Is mentioned. Hereinafter, the present invention will be described in detail using such phthalocyanine dyes as representative examples.

P _x in the above formula (I) is a substituted or unsubstituted phthalocyanine residue and / or a substituted or unsubstituted porphyrin residue, x is 1 or more and 4 or less, and y and z are each 0 or more and 3 or less. And any number satisfying the formula [1 ≦ x + y + z ≦ 4], and M ₁ represents a hydrogen atom, a metal element, a metal oxide, a metal hydroxide, or a metal halide. What is preferable as M ₁ is a metal element other than a hydrogen atom, such as Li, Na, K, Mg, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Ru. Rh, Pd, Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Si, Ge, Sn, Pb, Sb, Bi, and the like. Among these, Cu, Ni, Zn, Al and the like are particularly preferable, and Cu is most preferable. Preferred examples of the metal oxide include VO and GeO. Moreover, as a metal hydroxide, Si (OH) ₂ , Cr (OH) ₂ , Sn (OH) _2, etc. are mentioned preferably. Furthermore, as the metal _{halide, AlCl, SiCl 2, VCl,} VCl 2, VOCl, FeCl, GaCl, ZrCl , and the like.

M ₂ ⁺ represents at least one selected from a monovalent metal ion, a quaternary ammonium ion, a metal oxide ion, and an organic cation. When x is plural, M ₂ ⁺ may be the same or different. Examples of preferable monovalent metal ions include alkali metal ions. Preferred metal oxide ions include VO ²⁺ , RuO ₄ ⁻ , SnO ₃ ²⁻ , TcO ₄ ^{− and the} like. A preferred organic cation is the same as E in the following general formula (II) or (III), and is a cation selected from P ⁺ and S ⁺ . A more preferable embodiment of M ₂ ⁺ is a monovalent metal ion or a quaternary ammonium ion.

  A represents a group selected from a hydroxyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted carbamic acid group, and a substituted or unsubstituted aminoacetic acid group, and when y is plural, A may be the same or different. More preferably, A is an amino group.

  R is a hydrogen atom or an organic group, and when z is plural, R may be the same or different. Examples of the site in R include an alkylene chain, an alkenylene chain, an alicyclic alkyl chain, an aromatic ring, an azo bond, an amide bond, and a carbonyl group. These sites may be optionally substituted, and are selected from these sites. It may be a combination of connected. Further, when there are a plurality of z, Rs may be the same or different. Examples of functional groups for substituting the site in R include alkyl groups, alkenyl groups, sulfonic acids, carboxylic acids, hydroxyl groups, amide groups, amino groups, ketone groups, phenyl groups, pyridinium groups, imidazolium groups, and cyano groups. And these functional groups may also be substituted.

  The above dyes can be used alone or in combination of two or more, for example, a mixture of different phthalocyanine compounds, a mixture of different porphyrin compounds, a mixture of phthalocyanine compounds and porphyrin compounds, phthalocyanine compounds or porphyrin compounds and other structures. It can be used as a mixture with a coloring material having In the case of a mixture of water-soluble phthalocyanine compounds represented by the general formula (I), for example, in the case of a mixture of phthalocyanine of x = 1 and phthalocyanine of x = 2, x obtained when analyzing the components of the ink The value is a real number greater than 1 and less than 2. Similarly, y and z are real numbers greater than 0 and less than 3. Examples of other colorants include azo dyes (monoazo dyes, disazo dyes, trisazo dyes), triphenylmethane dyes, xanthene dyes, and the like.

  As the content of the dye used in the ink according to the present invention, the total dye amount in the ink is 0.05% by mass or more and 50% by mass or less from the viewpoint of the coloring property of the dye, including the above-described mixture. More preferably, the content is 0.1% by mass or more and 10% by mass or less.

  The ink according to the present invention is characterized by containing an onium cation compound having an amide bond, and the compound will be described below. As an onium cation compound that can be suitably used in the present invention, a compound containing a cation structure selected from the group consisting of ammonium, sulfonium, and phosphonium, an amide bond, and a counter anion in the molecule thereof. The compound which has is mentioned. Preferably, compounds represented by the following general formula (II) and general formula (III) are used.

  R in the above general formula (II) or (III) is an alkyl group, an alkenyl group, an oxyalkyl group, an oxyalkenyl group having 1 to 24 carbon atoms, which is unsubstituted or has a side chain and / or a terminal substituted. An organic group selected from a group, a cycloalkyl group, a cycloalkenyl group and an aromatic ring.

Specific examples of R include, for example, —CH ₃ , —C ₂ H ₅ , —C ₃ H ₇ , —C ₄ H ₉ , —C ₅ H ₁₁ , —C ₆ H ₁₃ , —C ₈ H ₁₇ , _{-C 10 H 21, -C 12 H} 25, -C 14 H 29, -C 16 H 33, -C 18 H 37, -CH = CH 2, -CH = CH-CH 3, -CH = CH-CH _{= CH 2, -CH = CH-} CH = CH-CH 3, -CH = CH-CH 2 -CH = CH 2, -CH 2 -CH = C = CH-CH 3, -O-C 2 H 5, —O—CH ₂ —CH═C═CH—CH ₃ , —C ₆ H ₁₂ —CH═CH—C ₂ H ₄ —CH═CH—C ₆ H ₁₃ , —CH ₂ —C ₆ H ₅ and —C ₆ H ₅ can be preferably exemplified. A part of the organic group may be substituted.

Examples of the substituent for R include a hydroxyl group, a halogen, and an organic anionic group. Examples of the organic anionic group include a carboxyl group, a sulfonic acid group, a phosphoric acid group, and a nitric acid group. Among these, it is preferable to use an alkyl group whose terminal is substituted with a carboxyl group, a sulfonic acid group, a salt thereof, or an ester group. Examples of counter ions of these anionic groups include inorganic cations such as Na, K, Li and onium cations. Examples of the group that esterifies these anionic groups include alkyl groups, and specifically, —CH ₃ , —C ₂ H ₅ , —C ₃ H ₇ , —C ₄ H ₉ , —C Preferable examples include ₅ H ₁₁ and —C ₆ H ₁₃ .

A in the general formula (II) or (III) is an alkylene group having 1 to 6 carbon atoms or an unsubstituted or substituted side chain alkylene group, alkenylene group, oxyalkylene group, oxyalkenylene group, cycloalkylene group, It is at least one organic group selected from a cycloalkenylene group and a divalent aromatic ring, specifically, —CH ₂ —, —C ₂ H ₄ —, —C ₃ H ₆ —, —C ₄ H _{8. -, - C 5 H 10 -} , - C 6 H 12 -, - CH = CH -, - CH = CH-CH 2 -, - CH = CH-CH = CH -, - CH = CH-CH = CH- _{CH 2 -, - CH = CH} -CH 2 -CH = CH -, - CH 2 -CH = C = CH-CH 2 -, - O-C 4 H 8 -, - O-CH 2 -CH = C = Preferred examples include CH—CH ₂ —, —CH ₂ —C ₆ H ₄ —, and —C ₆ H ₄ —.

E in the general formula (II) or (III) is a cation selected from N ⁺ , P ⁺ and S ^{+. In the} general formula (III), one E is N ⁺ , P ⁺ and S If it is a cation selected from ⁺ , the other E may be an atom selected from N, P and S.

  Z bonded to E is a hydrogen atom or an unsubstituted, side chain or substituted end group having 1 to 12 carbon atoms, an alkyl group, an alkenyl group, an oxyalkyl group, an oxyalkenyl group, a cyclo An organic group selected from an alkyl group, a cycloalkenyl group and an aromatic ring, and a plurality of Z present in one molecule may be the same or different. Specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, vinyl group, propenyl group, butadienyl group, pentadienyl group, cyclopropenyl group, cyclobutenyl group, cyclopentyl group, benzyl group And a phenyl group are preferable, and these organic groups may have a substituent selected from a hydroxyl group, a carboxyl group, and a ketone group. Particularly preferred Z is a substituted or unsubstituted alkyl group such as a methyl group, a methylol group, an ethyl group, a hydroxyethyl group, or a propyl group.

Further, m in the general formulas (II) and (III) is 3 when E is N ⁺ and P ⁺ , 2 when N, P and S ⁺ , and 1 in the case of S. It is.

G in the general formulas (II) and (III) is a group selected from a carbonyl group, a sulfonyl group, a thionyl group, and a phosphoryl group, and forms an amide bond with the adjacent N. Further, X ⁻ in the general formulas (II) and (III) represents a counter ion of the compound having the structure as described above.

With respect to the compounds represented by the above general formula (II) and general formula (III), more specific structures are shown in the following general formula (IV) and general formula (V). In these formulas, R, A, Z and X ⁻ are the same as those in formulas (II) and (III).

The onium cation compound represented by the general formula (II) and the general formula (III) has at least one selected from inorganic and / or organic anions as a counter ion represented by X ⁻ in the formula. Preferred examples of the counter ions include halogen ions, chloride ions, bromide ions, iodide ions, fluoride ions, hydroxide ions, carboxylate ions, nitrate ions, phosphate ions, and sulfate ions. When there are a plurality of counter ions, the counter ions may be the same or different.

  The content of the onium cation compound represented by the general formula (II) and the general formula (III) used in the ink according to the present invention is determined from the viewpoint of the liquid stability of the ink [onium cation equivalent / dye of the dye. The anion equivalent] ratio is preferably 0.01 to 2, and more preferably 0.25 to 1.0. The onium cation compounds as described above can be used alone or as a mixture. Furthermore, you may use with the mixture which mixed the compound of general formula (II), and the compound of general formula (III).

  Preferable specific examples of the dye represented by formula (I) and the onium cation compound represented by formula (II) or (III) used in Examples and Comparative Examples described below are shown below. Any of these compounds can be synthesized according to a known method. In the following, Pc represents phthalocyanine.

Dyes represented by general formula (I)

Compound represented by general formula (II)

Compound represented by general formula (III)

  In preparing an ink using each of the above-described compounds, water and other solvents and additives used in ordinary inks and paints can be added as other components constituting the ink. As the water, ion-exchanged water, purified water or the like can be used. As the solvent, a water-soluble organic solvent is preferably used. Specifically, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, isopropyl alcohol, 1,2-propanediol, 1,3 -Propanediol, 1,2-butanediol, 1,3-butanediol, ethylene glycol, diethylene glycol, ethylene glycol monobutyl ether, ethylene glycol diacetate, diethylene glycol monomethyl ether, glycerin, cyclohexanol, furfuryl alcohol, γ-butyrolactone, Although it is monoethanolamine etc., it is not limited to these. Moreover, you may use not only these alone but 2 or more types together.

  Examples of additives that can be contained in the ink according to the present invention include nonionic, anionic, and cationic surfactants, preservatives, fungicides, and pH adjusters. These additives may be arbitrarily selected from conventionally known compounds according to the purpose.

  Examples of the method for forming an image using the water-based ink of the present invention include ink jet printing and pen markers. The image forming method is not limited to this. As the ink jet method, both a bubble jet (registered trademark) type and a piezo jet type can be used.

  Next, the present invention will be specifically described with reference to examples and comparative examples. In the text, “part” is based on mass unless otherwise specified.

<Example 1>
In a sample bottle, the following ingredients are formulated so that the equivalent ratio of the onium cation compound to the dye is 0.5, and the mixture is stirred and mixed on a magnetic stirrer table using a stir bar. Was measured, and pH was adjusted with lithium hydroxide so that 7 ≦ pH ≦ 10, and the ink of this example was obtained.

(Ink composition)
-4 parts of the dye A-Onium cation compound (4)
(Onium cation equivalent / anion equivalent = 0.5)
1.6 parts ・ Diethylene glycol 8 parts ・ Glycerin 8 parts ・ Isopropyl alcohol 2.5 parts ・ Deionized water 75.9 parts

<Evaluation>
Using the ink obtained above, a monochrome solid pattern was printed on glossy paper (manufactured by Canon Inc .; Pro Photo Paper) using an inkjet printer (manufactured by Canon Inc .; PIXUS850i) to obtain an evaluation paper. Then, the fastness of the image was evaluated using the obtained evaluation paper. As the fastness, light resistance and ozone resistance were evaluated by the following methods.

(Light resistance)
The evaluation paper was put in a light resistance tester (manufactured by Atlas; Ci4000) and exposed to xenon light for 50 hours under the conditions of 40 ° C., 70% RH, and 0.39 W / m ² . The solid pattern in the evaluation paper before and after exposure was measured using a reflection densitometer (manufactured by Minolta; Spectral Reflectometer: CM2002) and evaluated with a color difference (ΔE). The obtained results are shown in Table 1.

(Ozone resistance)
The above evaluation paper is put in an ozone tester (Suga Test Instruments Co., Ltd .; ozone weather meter), and the evaluation paper has an ozone concentration of 3 ppm, a temperature of 40 ° C., and a relative humidity of 55% for 2 hours. Exposed. Then, the solid pattern in the evaluation paper before and after exposure was measured using a reflection densitometer in the same manner as the light resistance, and evaluated by color difference. The results are shown in Table 1.

<Examples 2 to 5>
The onium cation compound (4) used in Example 1 was changed to the onium cation compound (5), (6), (9), and (12), respectively, and the onium cation / anion equivalent ratio was changed to that of Example 1. The inks of Examples 2 to 5 were obtained in the same manner as in Example 1 except that the settings were the same. An evaluation paper was obtained using the obtained ink in the same manner as in Example 1, and the fastness of the obtained evaluation paper was evaluated in the same manner as in Example 1. Table 1 summarizes the types of onium cation compounds used in each Example and the evaluation results.

<Examples 6 to 27>
The dye A used in Example 1 was changed to another dye of the specific example described above, and the onium cation compound (4) used in Example 1 was changed to another onium cation compound of the specific example described above. Inks of Examples 6 to 27 were obtained in the same manner as in Examples 1 to 5, except that the onium cation / anion equivalent ratio was set in the same manner as in Examples 1 to 5. Each ink obtained was evaluated in the same manner as in Example 1. Table 1 summarizes the dye species, onium cation compound species, and evaluation results used in each Example.

<Comparative Examples 1-5>
According to the above-described Examples, inks of Comparative Examples 1 to 5 were prepared in the same manner as in the Examples except that only the onium cation compound was not used. And it evaluated similarly to the Example. Table 2 summarizes the dye types used in each comparative example and the evaluation results.

  As shown in Table 1 above, the color difference (ΔE) before and after the test was smaller in each of the examples than in the comparative example having the same dye and containing no onium cation compound. The image suggests a decrease in color change before and after the light degradation and ozone degradation tests, and it is clear that the fastness to light and ozone resistance is improved.

  As is clear from the results of Tables 1 and 2 above, dyes having an anionic group, in particular, water-soluble phthalocyanine dyes and / or dyes having an amide bond can be contained in the ink by a simple method. Alternatively, an image formed with an aqueous ink using a porphyrin dye has a much improved fastness as compared with the case of the ink containing no onium cation compound in the comparative example.

As an application example of the present invention, an ink for ink jet recording that gives an image having high fastness excellent in light resistance and ozone resistance can be mentioned.

Claims (4)

  An aqueous ink comprising at least a dye and an onium cation compound, wherein the onium cation compound has an amide bond.   2. The aqueous solution according to claim 1, wherein the dye is a dye having an anionic group, and the ratio of [onium cation equivalent / anion equivalent] of the onium cation compound and the dye having the anionic group is 0.01 to 2. 3. ink. The water-based ink according to claim 1, wherein the dye contains at least a water-soluble dye represented by the following general formula (I).

(P _x in the above formula is a substituted or unsubstituted phthalocyanine residue and / or a substituted or unsubstituted porphyrin residue, x is 1 or more and 4 or less, and y and z are each 0 or more and 3 or less, And any number satisfying the formula [1 ≦ x + y + z ≦ 4], M ₁ represents at least one selected from a hydrogen atom, a metal element, a metal oxide, a metal hydroxide, and a metal halide, and M ₂ ⁺ Represents at least one selected from monovalent metal ions, quaternary ammonium ions and metal oxide ions, and organic cations, and when x is plural, M ₂ ⁺ may be the same or different. Represents a group selected from a hydroxyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted carbamic acid group and a substituted or unsubstituted aminoacetic acid group, and when y is plural, A may be the same or different; Is a hydrogen atom or An organic group, when z is plural R may be the same or different.) The water-based ink according to claim 1, wherein the onium cation compound is a compound having a linear or multi-branched structure represented by the following general formula (II) or general formula (III).

(R in the above formula is an alkyl group, alkenyl group, oxyalkyl group, oxyalkenyl group, cycloalkyl group, cycloalkenyl group which is unsubstituted or has a side chain and / or a terminal substituted in the range of 1 to 24 carbon atoms. And an organic group selected from aromatic rings, A is an alkylene group having 1 to 6 carbon atoms, or an alkylene group, alkenylene group, oxyalkylene group, oxyalkenylene group, cycloalkylene group, And at least one group selected from an alkenylene group and a divalent aromatic ring, E is a cation selected from N ⁺ , P ⁺ and S ⁺ , or an atom selected from N, P and S, and Z is A hydrogen atom or an unsubstituted, side chain, or substituted alkyl group, alkenyl group, oxyalkyl group, oxyalkenyl group, cycloalkyl group having 1 to 12 carbon atoms. A plurality of Z in one molecule may be the same or different, m is 3 when E is N ⁺ and P ⁺ , and N, 2 for P and S ⁺ and 1 for S. G is a group selected from a carbonyl group, a sulfonyl group, a thionyl group and a phosphoryl group, and X ⁻ is a counter ion.)