JP3065946B2 - Water-based ink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink having improved print density of a printed matter, and improved fixability and water resistance to a printed matter, and more particularly to a water-based ink useful as an ink for ink-jet recording. It is about.

[0002]

2. Description of the Related Art Water-based inks are often used for printing and writing implements because of their ease of production and handling. For example, printer devices have become widespread due to the recent development and spread of computers, and water-based inks have been actively used in such printer devices.

As ink used in an ink jet printer which is one of typical printer devices, a water-soluble dye which is usually dissolved in water is used in order to prevent the nozzle from being clogged with ink. The use of the water-soluble dye makes it difficult for the ink to clog the nozzles, but has the problem that the water resistance of the printed matter is poor.

In order to improve the water resistance of the ink for ink jet recording, a pigment is used as the ink (Japanese Patent Application Laid-Open Nos. 4-28776, 4-189876, 4-3599071, 4-35972). Gazette, etc.) or using a non-aqueous liquid medium (JP-A-4-26147)
No. 8) and the use of a dye having excellent water resistance (US Pat. No. 4,963,189) has been proposed.

However, when a pigment is used as an ink, there is a possibility that the saturation of a printed matter is reduced and a problem such as clogging in a nozzle is caused. In addition, fixing to a printing object such as paper or an OHP sheet is performed. The printability was insufficient, and there was a problem in the record preservability as a printed matter. Other proposals have not yet sufficiently solved the problem of improving fixability. Therefore, an ink that sufficiently satisfies both the water resistance and the fixability has not been obtained.

Accordingly, an object of the present invention is to provide a water-based ink in which the print density of a printed matter is improved, and the fixability to a printed material and the water resistance are improved.

Another object of the present invention is to provide a water-based ink which is particularly useful as an ink for ink-jet recording.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object. As a result, the coloring property of the dye and the pigment is impaired by adsorbing the dye or the pigment to the micelle of a specific polyester. It has been found that the print density of the printed matter is improved without being printed, and that the fixability to the printed matter and the water resistance are improved.

The present invention has been made based on the above findings, and comprises a suspension of a polyester to which a dye or a pigment has been adsorbed.
A diol component represented by the formula, a dimer acid, and a divalent or higher polyvalent carboxylic acid other than the dimer acid (provided that the acid component is
A water-based ink obtained by co-condensation polymerization of at least one component selected from the group consisting of an acid anhydride thereof and a lower alkyl ester thereof, excluding cyclohexene dicarboxylic acid) . By providing the above, the above object has been achieved.

[0010]

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Further, the present invention provides a water-based ink for ink-jet recording characterized by using the above-mentioned water-based ink.

Further, the present invention provides, as a preferred method for producing the above-mentioned aqueous ink, a diol component represented by the following formula (1), a dimer acid, and a divalent or higher polyvalent carboxylic acid other than the dimer acid (provided that: As the acid component, cyclohexenedica
Except carboxylic acid), acid value obtained by co-condensation polymerization polyester of 3~100KOHmg / g and one or more components selected from the group consisting of an acid anhydride thereof and lower alkyl esters, dyes or pigments A water-based ink characterized by adding a neutralizing agent to the carboxyl group in the polyester by adding a neutralizing agent, and then adding water, and then distilling off the solvent and inverting the water-based ink. It provides a method.

[0013]

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[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The water-based ink of the present invention is characterized by comprising a suspension of a specific polyester to which a dye or a pigment is adsorbed. That is, at least a part of the dye or the pigment is adsorbed on the micelle formed by the polyester, or is encapsulated in the micelle. That is, in the present specification, "the dye or the pigment is adsorbed" means that at least a part of the dye or the pigment is adsorbed on the micelle formed by the polyester, or is encapsulated in the micelle. . And the water-based ink of the present invention,
The polyester micelles having the dye or pigment adsorbed therein are present as suspensions in water.

The above specific polyester is represented by the following formula (1)
A diol component [hereinafter, referred to as a component (a)]
And a dimer acid [hereinafter, referred to as component (b)], a divalent or higher polyvalent carboxylic acid other than dimer acid, an acid anhydride thereof, and a lower alkyl ester thereof.
It is obtained by copolycondensation of at least one kind of component (hereinafter, referred to as component (c)).

[0016]

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The diol component represented by the above formula (1), which is the component (a), is not particularly limited, and is, for example, an alkylene oxide adduct of bisphenol A, preferably an ethylene oxide or propylene oxide adduct of bisphenol A. Yes, specifically, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,
2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.
It is preferable to use 0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, or the like. it can.

In obtaining the polyester by co-condensation polymerization, the diol component represented by the above formula (1) and another alcohol component can be used in combination. In this case, the proportion of the diol component represented by the above formula (1) is preferably 40 to 100 mol% in all the alcohols used. Other alcohol components include, for example, aliphatic diols and trivalent or higher alcohols. In this case, the proportion of the aliphatic diol is preferably less than 20 mol% in the total alcohol used, and the proportion of the trihydric or higher alcohol is preferably less than 60 mol% in the total alcohol used. is there. Examples of the aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol,
1,4-butanediol, neopentyl glycol,
1,4-butenediol, 1,5-pentanediol,
Examples include 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples of the above trihydric or higher alcohols include sorbitol, 1, 2, 3,
6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,
2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like. Can be

Next, the dimer acid as the component (b) will be described. In the present specification, "dimer acid" refers to a substance synthesized by a polymerization reaction of two molecules of unsaturated fatty acids. As the dimer acid, for example,
An acyclic dimer acid represented by the following formulas (I) and (II):
Monocyclic dimer acids represented by the following formulas (III), (IV) and (V) and bicyclic dimer acids represented by the following formulas (VI) and (VII) can be used. By using the dimer acid as the copolycondensation component in the polyester, the formability and stability of the suspension are improved, and the amounts of dye and pigment adsorbed are improved. The dimer acids may be used alone or in combination of two or more. As the dimer acid, commercially available products can also be used. Such commercially available products generally include acyclic dimer acids represented by the above formulas (I) and (II) and monocyclic dimer acids represented by the above formulas (III), (IV) and (V). Dimer acid, and the above formula (V
It is composed of a complex mixture of bicyclic dimer acids represented by I) and (VII), and is, for example, Unidim 22 (trade name, acyclic rich type) manufactured by Union Cap or Haridimer 250K (trade name) manufactured by Harima Kasei , Monocyclic / bicyclic rich type) and the like.

[0020]

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[0021]

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[0022]

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Among the above dimer acids, it is preferable to use an acyclic dimer acid from the viewpoint of improving the formability and stability of the suspension, and it is particularly preferable to use the dimer acid represented by the above formula (I).

Next, the component (c) will be described. The component (c) is selected from the group consisting of divalent or higher polycarboxylic acids other than the dimer acid, acid anhydrides and lower alkyl esters thereof. One or more components are used.

As the divalent or higher polycarboxylic acid other than the above dimer acid, divalent carboxylic acid and trivalent or higher carboxylic acid are used. As the divalent carboxylic acid,
Although not particularly limited, for example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid,
Phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-
Dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid and the like are preferably used. On the other hand, the trivalent or higher carboxylic acid is not particularly limited. For example, 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid,
1,2,4-naphthalenetricarboxylic acid, 1,2,4-
Butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 2,7,8-octanetetracarboxylic acid, pyromellitic acid, trimellitic anhydride, embolic trimer acid and the like are preferably used. In addition, as the lower alkyl esters of these divalent or higher polycarboxylic acids, alkyl esters having 1 to 4 carbon atoms are preferably used. In particular, as the polyvalent carboxylic acid, divalent carboxylic acids such as maleic acid, fumaric acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and succinic acid, or 1,2,4-
It is preferable to use benzenetricarboxylic acid or trimellitic anhydride.

The above (a) in the above polyester
The molar ratio of the component, the component (b), and the component (c) is
Acid value, number average molecular weight and Tg of the polyester described below
For example, the above components may be freely combined and selected within a range in which Tg is 20 ° C. or more, depending on the values such as the above. In particular, as a preferable example of the component ratio, the component (b) is preferably 0.05 to 0.7 mol, more preferably 0.1 to 0.5 mol, per 1 mol of the component (a). It is even more preferred. On the other hand, the component (c) is preferably 0.6 to 1.2 mol, more preferably 0.8 to 1.1 mol, per 1 mol of the component (a).

The above-mentioned polyester is obtained by copolycondensation of the above-mentioned component (a), the above-mentioned (b) and the above-mentioned component (c). The method of the copolycondensation is not particularly limited, and a known method is used.

The polyester is preferably capable of forming micelles capable of adsorbing dyes or pigments, but is capable of forming micelles capable of enclosing the dyes or pigments in whole or in part. However, it can be used without any particular limitation as long as the effects of the present invention are not impaired.

The polyester preferably used in the present invention as the above polyester has an acid value based on JIS K 0070 of 3 to 100 KOH mg / g. If the acid value is less than 3 KOH mg / g, a suspension in which a dye or a pigment is stably adsorbed may not be obtained. If the acid value exceeds 100 KOH mg / g, the water resistance and fixability of the ink may be poor. , Within the above range. The acid value is 3-70 KOHmg
/ G is more preferable.

The acid value of the polyester can be determined, for example, by changing the addition ratio of the component (a), the component (b), and the component (c), using a carboxylic acid ester as the component (c), It can be adjusted by blocking the component (c) with a monohydric alcohol.

The above polyester has a number average molecular weight (converted to polystyrene by gel permeation chromatography) of 500 to 100,000, particularly 1000.
A value of from 10,000 to 10,000 is preferred from the viewpoint of the fixability and water resistance of the ink after printing, the formability of the suspension, and the prevention of scorching on the printer head, particularly when used as ink for inkjet recording.

The above polyester has a Tg (glass transition point) measured by DSC (differential scanning calorimetry).
However, in an ink jet recording method using a piezoelectric element, 20
C. or higher, preferably 30 ° C. or higher in an ink jet recording system using thermal energy, and more preferably 40 ° C. or higher and 150 ° C. or lower in both the piezoelectric element system and the thermal energy system. If the Tg is below the lower limit of the above condition, the polyester may solidify in the nozzle of the printer, and the nozzle may be clogged. In addition, when paper printed using the water-based ink of the present invention is overlaid, paper reflection of the ink may occur. The Tg of the polyester can be adjusted, for example, by changing the addition ratio of the component (a), the component (b), and the component (c).

Next, the dyes and pigments adsorbed by the polyester micelles will be described. As the dye, any dye can be used as long as it can be adsorbed by the polyester, and examples thereof include oil dyes, disperse dyes, direct dyes, acid dyes, and basic dyes. It is particularly preferable to use an oil dye and a disperse dye from the viewpoint of adsorptivity. The disperse dye is not limited to the following, but particularly preferred specific examples include C.I. I. Disperse Yellow 5, 42, 54, 64, 79, 82, 83, 93, 9
9, 100, 119, 122, 124, 126, 16
0, 184: 1, 186, 198, 199, 204, 2
24 and 237; I. Disperse Orange 13,
29, 31: 1, 33, 49, 54, 55, 66, 7
3, 118, 119 and 163; I. Disperse Red 54, 60, 72, 73, 86, 88, 91, 9
2, 93, 111, 126, 127, 134, 135,
143, 145, 152, 153, 154, 159, 1
64, 167: 1, 177, 181, 204, 206,
207, 221, 239, 240, 258, 277, 2
78, 283, 311, 323, 343, 348, 35
6 and 362; I. Disperse Bio Red 3
3; I. Disperse Blue 56, 60, 73, 8
7, 113, 128, 143, 148, 154, 15
8, 165, 165: 1, 165: 2, 176, 18
3, 185, 197, 198, 201, 214, 22
4, 225, 257, 266, 267, 287, 35
4, 358, 365 and 368; and C.I. I. Disperse Green 6: 1 and 9; The oily dye is not limited to the following, but particularly preferred specific examples include, for example, C.I. I. Solvent Black 3, 7, 27, 29 and 34; C.I. I. Solvent Yellow 14, 16, 19, 29, 56, 82
And 162; I. Solvent Red 1, 3, 8,
18, 24, 27, 43, 51, 72, 73, 132 and 218; I. Solvent Violet 3; C.I.
I. Solvent Blue 2, 11, and 70; I. Solvent Green 3 and 7; and C.I. I. Solvent Orange 2 and the like. The direct dye is not limited to the following, but particularly preferred specific examples include, for example, C.I. I. Direct Black 19 and the like. The acidic dye is not limited to the following, but particularly preferred specific examples include, for example, C.I. I. Acid black 2 and 52;
C. I. Acid Yellow 23; I. Acid
Red 51, 87 and 92; and C.I. I. Acid
Blue 1, 9 and 74. The basic dye is not limited to the following, but particularly preferred specific examples include, for example, C.I. I. basic·
Yellow 2 and 11; I. Basic red 1 and 13; I. Basic Violet 1, 3, 7
And 10; and C.I. I. Basic Blue 5, 7,
9 and 26.

The dye used in the present invention is preferably dissolved in a solvent, for example, a ketone-based solvent in an amount of 20 g / l or more, from 100 to 600 g, from the viewpoint of being efficiently adsorbed to the polyester by phase inversion emulsification described below. / L is more preferable.

On the other hand, as the pigment used in the aqueous ink of the present invention, any pigment can be used without particular limitation as long as it can be adsorbed by the polyester. For example,
Azo lakes, azo pigments such as insoluble azo pigments, condensed azo pigments, chelate azo pigments, and polycyclics such as phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthaloni pigments, etc. Pigments,
Dye lakes such as basic dye lakes and acid dye lakes; organic pigments such as nitro pigments, nitroso pigments, aniline black and daylight fluorescent pigments; and inorganic pigments such as titanium oxide, iron oxide and carbon black. Can be In addition, any pigment that is not described in the color index can be used as long as it can be dispersed in the aqueous phase. Further, those obtained by surface treatment of the above pigment with a surfactant or a polymer dispersant,
Graft carbon and the like can of course be used. Among the above pigments, it is particularly preferable to use azo pigments, phthalocyanine pigments, anthraquinone pigments, and carbon black pigments.

In the present invention, the above-mentioned dyes and pigments may be used alone or in combination. When both are used in combination, the mixing ratio (weight) of the dye and the pigment is the former: the latter = 10: 9
It may be freely selected in the range of 0 to 90:10. In this specification, the term "pigment" refers to fine particles of solids insoluble in water, solvents, oils, etc., whereas the term "dye" refers to dyes dissolved in water or solvents. [Chemical Encyclopedia of Color Synthetic Organic Chemistry, edited by CMC Co., Ltd., p. 45].

The average particle size of the suspension of the polyester to which the dye or pigment is adsorbed is 0.005 to 0.5.
Preferably it is 5 μm. The average particle diameter is 0.0
If it is less than 05 μm, ink bleeding may occur, and if it exceeds 0.5 μm, the dispersion stability of the suspension itself may be reduced. The average particle size is 0.01 to 0.3 μm
m is more preferable. The average particle diameter can be adjusted, for example, by changing the conditions of phase inversion emulsification described below.

In the water-based ink of the present invention, the above polyester is preferably incorporated in the ink in an amount of 1 to 50% by weight, more preferably 2 to 30% by weight. If the amount of the polyester is less than 1% by weight, the print density is insufficient. If the amount is more than 50% by weight, the storage stability of the suspension as ink deteriorates. The printer head may be clogged due to thickening of the ink and aggregation of the suspension due to the evaporation of the ink at the leading end portion.

On the other hand, the above-mentioned dye or pigment is preferably blended in the ink at 1 to 30% by weight,
More preferably, it is blended at 5% by weight. If the amount of the dye or pigment is less than 1% by weight, the print density is insufficient, and if the amount exceeds 30% by weight, the print density cannot be significantly improved. Since the stability over time is reduced and the average particle diameter tends to increase, it is preferable to be within the above range.

The water-based ink of the present invention contains, in addition to a suspension of polyester having the above-mentioned dye or pigment adsorbed with water as a medium, various conventionally known additives such as a wetting agent such as a polyhydric alcohol. Agents, dispersants, antifoaming agents such as silicones, surface tension regulators such as various cationic, anionic or nonionic surfactants, fungicides such as chloromethylphenol and / or chelating agents such as EDTA, And an oxygen absorbent such as sulfite.

The wetting agent is not particularly limited, but may be, for example, glycols such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol and polyethylene glycol; glycerin; diethylene glycol diethyl ether. , Diethylene glycol monobutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, methyl carbitol, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, diethyl carbitol, triethylene glycol monomethyl ether, triethylene Glycol monoethyl ether and propylene glycol monomethyl Ethers of polyhydric alcohols such as ether, acetates; thiodiglycol; N- methyl -
2-pyrrolidone; 1,3-dimethylimidazolidinone;
Nitrogen-containing compounds such as triethanolamine; formamide; dimethylformamide; and one or more of dimethyl sulfoxide can be used. The amount of these wetting agents is not particularly limited, but may be preferably 0.1 to 50% by weight in the aqueous ink of the present invention.
More preferably, 0.1 to 30% by weight can be added.

The dispersing agent is not particularly limited. For example, as anionic surfactants, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkane or olefin sulfonate, alkyl sulfate ester salt Surfactants selected from the group consisting of polyoxyethylene alkyl or alkyl aryl ether sulfates, alkyl phosphates, alkyl diphenyl ether disulfonates, ether carboxylates, alkyl sulfosuccinates, α-sulfofatty acid esters, and fatty acid salts Agents, condensates of higher fatty acids and amino acids, naphthenates and the like can be used.
Anionic surfactants preferably used are alkylbenzene sulfonates (especially those of straight chain alkyl),
Alkanes or olefin sulfonates (particularly secondary alkane sulfonates, α-olefin sulfonates), alkyl sulfates, polyoxyethylene alkyl or alkyl aryl ether sulfates (particularly polyoxyethylene alkyl ether sulfates) ), An alkyl phosphate (especially monoalkyl), an ether carboxylate, an alkyl sulfosuccinate, an α-sulfofatty acid ester, and a fatty acid salt. Acid salts (especially linear alkyl), polyoxyethylene alkyl or alkylaryl ether sulfates (especially polyoxyethylene alkyl ether sulfates), and alkyl sulfates. is there. These can be used alone or in combination of two or more. In addition, as the cationic surfactant, an aliphatic amine salt, a quaternary ammonium salt, a sulfonium salt, a phosphonium salt, or the like can be used. These can be used alone or in combination of two or more. Further, as a nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester and alkyl A surfactant or the like selected from the group consisting of (poly) glycoxides can be used. Nonionic surfactants preferably used are surfactants selected from polyoxyethylene alkyl ethers and polyoxyethylene alkyl aryl ethers. These can be used alone or in combination of two or more. In addition, as the amphoteric surfactant, an amino acid type or betaine type compound or the like can be used.

Examples of the polymer dispersants include proteins such as gelatin and casein, natural gums such as gum arabic, glucoxides such as saponin, cellulose derivatives such as alkylcellulose, carboxyalkylcellulose and hydroxyalkylcellulose, lignin sulfonate, Natural polymers such as shellac, polyacrylates, styrene-acrylic acid copolymer salts, vinylnaphthalene-acrylic acid copolymer salts, styrene-maleic acid copolymer salts, vinylnaphthalene-maleic acid copolymer salts, β-naphthalenesulfonic acid formalin condensate, anionic polymers such as polyphosphoric acid, and nonionic polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and polyalkylene glycol, and the like. More than seeds can be used That. In particular, it is particularly preferable to use a compound represented by the following formula (2) from the viewpoint that the average particle size of the suspension can be reduced.

[0044]

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In the above formula (2), a hydrogen atom is preferably used as R ′. Also, as R ″,
Preferably, a methylene group is used. As M, ions of alkali metals such as sodium and potassium are preferably used. Also, l is preferably 10
0 to 800. Further, the compound represented by the above formula (2) preferably has an HLB value of 5 to 15 from the viewpoint of exhibiting an effect as a dispersant and having an effect of suppressing an increase in the average particle diameter of the suspension.

As the compound represented by the above formula (2), commercially available products can also be used. As such a commercially available product, for example, a dispersant Demol SNB, M manufactured by Kao Corporation
S, N, SSL, ST, P (trade name).

The compounding amount of the compound represented by the above formula (2) is not particularly limited.
Preferably, it is blended in an amount of 10 to 10% by weight. If the compounding amount of the compound is less than 0.01% by weight, it is difficult to reduce the particle size of the suspension. If it exceeds 10% by weight, the average particle size of the suspension increases, the suspension stability decreases, and gelation occurs. Therefore, it is preferable to be within the above range. More preferably, the compounding amount of the compound represented by the above formula (2) is in the aqueous ink of the present invention.
0.1 to 1% by weight.

The defoaming agent is not particularly limited, but a compound represented by the following formula (3), particularly, a compound represented by the following formula (4) may be used in preparing an ink. It is particularly preferable in terms of suppressing the generation of bubbles and adjusting the surface tension of the ink.

[0049]

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[0050]

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In the above formula (3), R ₁ , R ₂ , R ₃ and R ₄ are preferably the same or different C ₁ -C ₅ lower alkyl groups or phenyl groups, and m and n are preferably 10 or more. Is an integer from １００100, and R ₅ and R ₆ are preferably the same or different C ₁ -C ₅ lower alkyl groups or phenyl groups.

As the compound represented by the above formula (3) or (4), commercially available products can also be used. Examples of such commercially available products include KF96 manufactured by Shin-Etsu Silicone Co., Ltd.
66, 69, KS68, 604, 607A, 602, 6
03, KM73, 73A, 73E, 72, 72A, 72
C, 72F, 82F, 70, 71, 75, 80, 83
A, 85, 89, 90, 68-1F, 68-2F (trade name) and the like.

The amount of the compound represented by the above formula (3) or (4) is not particularly limited, but is preferably 0.001 to 2% by weight in the aqueous ink of the present invention.
If the compounding amount of the compound is less than 0.001% by weight, bubbles are easily generated at the time of preparing the ink, and it is difficult to remove small bubbles in the ink. If it exceeds 2% by weight, the generation of bubbles is suppressed. During printing, repelling may occur in the ink and the print quality may be degraded. More preferably, the above formula (3) or (4)
The compounding amount of the compound represented by is 0.005 to 0.5% by weight in the aqueous ink of the present invention.

As the surface tension adjusting agent, the above-mentioned silicone-based antifoaming agents and various surfactants of cationic, anionic or nonionic type can be used. Particularly, a silicone-based antifoaming agent represented by the above formula (3) or (4), an ethylene oxide compound of an alkyl phenol represented by the following formula (5), and an ethylene of an acetylene glycol represented by the following formula (6) The use of an oxide adduct is preferable in terms of suppression of bubble generation, ease of adjusting the surface tension of the ink, ink dischargeability, less bleeding, and non-uniform print density.

[0055]

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[0056]

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When using the above surface tension modifier, one or more of these compounds can be used.
It is desirable to add 0.005 to 15% by weight in the water-based ink of the present invention. If the amount is less than 0.005%, the above properties may not be exhibited,
If the content is more than 15% by weight, on the contrary, bleeding or uneven printing density may occur to lower the printing quality or lower the liquid stability of the ink.

The water-based ink of the present invention preferably has a viscosity at 20 ° C. of 0.5 to 5 cps, more preferably 1 to 3 cps, particularly from the viewpoint of ejection stability when used in an ink jet printer. is there. Further, the aqueous ink of the present invention has a surface tension at 20 ° C.
25 to 50 dyn / cm from the viewpoint of the permeability to the print object
And more preferably 30 to 45 dy.
n / cm.

The water-based ink of the present invention is particularly useful as a water-based ink for inkjet recording. In this case, the water-based ink can be used for any of a piezoelectric type and a thermal jet type ink jet printer.

When color printing is performed by the subtractive color mixture method using the water-based ink of the present invention, the color ink containing the respective dyes or pigments of black, yellow, magenta and cyan is used.
By using a color ink set composed of various types of inks (black ink, yellow ink, magenta ink, and cyan ink), the print density of the printed image is high, the blur is small,
It is preferable because the water resistance and the fixing property are improved, and the color reproducibility is also improved.

Next, a preferred method for producing the water-based ink of the present invention will be described. The aqueous ink of the present invention is preferably produced by so-called phase inversion emulsification described below.

Here, the phase inversion emulsification is carried out by the diol component represented by the above formula (1) (that is, the component (a)), the dimer acid (that is, the component (b)), and the components other than the dimer acid. The acid value obtained by co-condensation polymerization of at least one component selected from the group consisting of a divalent or higher polycarboxylic acid, an acid anhydride thereof and a lower alkyl ester thereof (that is, the component (c)), 3 to 100 KOH mg / g polyester is added to a solvent together with a dye or a pigment, a neutralizing agent is added to ionize the carboxyl groups in the polyester, and then water is added. Phase inversion.

First, the polyester is added to a solvent together with a dye or a pigment. In this case, the polyester is
It is preferable to add 5 to 50 parts by weight to 100 parts by weight of the solvent from the viewpoint of forming a suspension. Examples of the solvent include, but are not particularly limited to, ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, methyl isobutyl ketone, and methyl isopropyl ketone. Of these, methyl ethyl ketone is preferably used.

Next, a neutralizing agent is added to a mixture of the polyester, the dye or pigment, and the solvent. Thereby, the carboxyl groups in the polyester are ionized. The neutralizing agent can be used without any particular limitation as long as it can ionize a carboxyl group in the polyester. Such neutralizing agents include, for example, aqueous ammonia, aqueous alkaline solutions of monovalent inorganic salts such as lithium hydroxide, sodium hydroxide and potassium hydroxide, allylamine, isopropylamine, diisopropylamine,
Ethylamine, diethylamine, triethylamine, 2
-Ethylhexylamine, 3-ethoxypropylamine, diisobutylamine, 3-diethylaminopropylamine, tri-n-octylamine, t-butylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine,
n-propanolamine, butanolamine, 2-amino-4-pentanol, 2-amino-3-hexanol, 5-amino-4-octanol, 3-amino-3-
Methyl-2-butanol, monoethanolamine, diethanolamine, dimethylethanolamine, triethanolamine, isopropanolamine, neopentanolamine, diglycolamine, ethylenediamine,
1,3-diaminopropane, 1,2-diaminopropane, 1,6-diaminohexane, 1,9-diaminononane, 1,12-diaminododecane, dimer fatty acid diamine, 2,2,4-trimethylhexamethylene diamine ,
2,4,4-trimethylhexamethylenediamine, hexamethylenediamine, N-aminoethylpiperazine, N
And amines such as -aminopropylpiperazine, N-aminopropyldipiperidipropane, and piperazine. In particular, it is preferable to use sodium hydroxide, potassium hydroxide, triethylamine and dimethylethanolamine as the neutralizing agent, because the resulting suspension has a smaller particle size and the suspension stability is further improved. In particular, it is more preferable to use sodium hydroxide and potassium hydroxide as the neutralizing agent because the heat resistance of the obtained suspension is improved.
The amount of the neutralizing agent used may be an amount that can at least ionize the carboxyl groups in the polyester.

After the addition of the neutralizing agent, water is added to the mixture to cause phase inversion. This produces a suspension of polyester in the aqueous phase. The amount of water to be added is preferably 100 to 300 parts by weight based on 100 parts by weight of the mixed solution. In this case, it is preferable to add a compound obtained by adding the compound represented by the formula (2) to water to the mixed solution because the average particle diameter of the suspension can be reduced. Further, the above formula (3) or (4) is added to water.
It is preferable to add the compound represented by the formula (1) to the above-mentioned mixed liquid, since the generation of bubbles can be suppressed and the surface tension can be adjusted. Equation (2) above
As described above, the amount of the compound represented by is preferably 0.01 to 10% by weight in the ink finally obtained. On the other hand, the amount of the compound represented by the above formula (3) or (4) is preferably such that it becomes 0.001 to 2% by weight in the ink finally obtained as described above.

After the phase inversion is completed, the solvent in the mixture is removed by heating the system under reduced pressure, and a predetermined amount of water is removed, whereby a dye or pigment having a desired concentration is obtained. A suspension of the adsorbed polyester is obtained.

In preparing the aqueous ink of the present invention, it is preferable to remove coarse particles. For example, the ink after mixing is filtered under pressure with a filter or treated with a centrifugal separator to remove particles having a particle size of preferably 2 μm or more, more preferably 1 μm or more, and still more preferably 0.5 μm or more. An ink without clogging is obtained.

The water-based ink of the present invention is particularly useful as a water-based ink for ink-jet recording as described above, but can also be used as other inks, for example, as ink for writing implements such as general fountain pens, ball-point pens, and felt-tip pens. is there.

[0069]

EXAMPLES Next, the effectiveness of the water-based ink of the present invention will be illustrated by examples. However, it goes without saying that the present invention is not limited to such an embodiment.

Example 1 Polyoxypropylene (2.
2) 1050 g of 2,2-bis (4-hydroxyphenyl) propane, 30% of the dimer acid compound represented by the above formula (I), and 10% of the dimer acid compound represented by the above formula (III) 242 g of a dimer acid mixture, 300 g of fumaric acid, and 1.5 g of hydroquinone were placed in a glass 2-liter four-necked flask, and a thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube were attached thereto. The reaction was carried out while stirring at 210 ° C. under a nitrogen stream in a mantle heater. The degree of polymerization is AST
Pursuit was performed from the softening point according to ME28-67, and the reaction was terminated when the softening point reached 95 ° C. The obtained polyester was a pale yellow solid and had a Tg of 45 ° C.
Met. The acid value of the polyester based on JIS K 0070 was 26 KOH mg / g, and the number average molecular weight (in terms of polystyrene by gel permeation chromatography) was 3,000. Next, 150 g of the above polyester and an oily dye (manufactured by Orient Chemical, VALIFA
ST BLUE 2606) 40 g, and methyl ethyl ketone 500
g was placed in a separable flask, and the inside of the flask was replaced with N _2, followed by stirring to completely dissolve the polyester and the oily dye in methyl ethyl ketone. Subsequently, 9.85 g of triethylamine was added to ionize the carboxyl groups in the polyester. Further, 960 g of ion-exchanged water was dropped and stirred, and the mixture was heated to 40 ° C. under reduced pressure to remove methyl ethyl ketone, and a 20% by weight aqueous cyanide of a polyester suspension (average particle size: 0.05 μm) enclosing the dye was used. Ink was obtained.

Example 2 A dimer acid [Unidim 22 (trade name), manufactured by Union Cap Co.] was used as the component (b), and fumaric acid 25 was used as the component (c).
A polyester was obtained in the same manner as in Example 1 except that a mixture of 3 g and 115 g of trimellitic anhydride was used (acid value: 37 KOH mg / g, Tg: 51.3 ° C., number average molecular weight: 2800). Example 1 was repeated except that 9.70 g of dimethylethanolamine was used in place of triethylamine as a neutralizing amine using this polyester.
Dye (Oient Chemical, OIL
20% by weight of a water-based magenta ink of a polyester suspension (average particle size: 0.02 μm) enclosing the same (pink 308).

[Example 3] Instead of 960 g of ion-exchanged water in Example 2, ion-exchanged water 9 containing 3 g of Demol N (dispersant, HLB value 8.51) manufactured by Kao Corporation.
Except for using 60 g, a polyester suspension (average particle diameter; encapsulated with a dye (manufactured by Orient Chemical Co., Ltd., OIL YELLOW 129)) is operated in the same manner as in Example 2.
0.03 μm) of a 20% by weight aqueous yellow ink.

[Example 4] In place of 960 g of ion-exchanged water in Example 2, 3 g of Demol N (dispersant, HLB value 8.51) manufactured by Kao Corporation and KM manufactured by Shin-Etsu Silicone were used.
Ion-exchanged water containing 0.12 g of 71 (antifoaming agent) 96
Pigment (carbon black: MA-100, manufactured by Mitsubishi Kasei) 30 by the same operation as in Example 2 except that 0 g was used.
g of a polyester suspension (average particle size: 0.07 μm) containing 20% by weight of a water-based black ink.

Example 5 80 g of a water-based ink of a polyester suspension obtained in Example 1 10 g of diethylene glycol 9.8 g of glycerin 0.20 g of acetylenol EL The above-mentioned components were mixed, and the resulting dispersion was mixed. The mixture was filtered through a 5-micron filter to remove dust and coarse particles to obtain a cyan ink for inkjet. Using this ink, printing was performed with a commercially available Canon Micro Bubble Jet Printer (Model No. BJ-10VL), and the ink discharge amount, print density, bleeding, water resistance, anti-clogging property and fixability were evaluated by the following methods. Table 1 shows the results.

<Ink Discharge Amount> Solid printing was performed using recycled paper for PPC [manufactured by Nippon Kaishi Paper Co., Ltd.].
Measure the weight of the ink cartridge before and after printing,
The ink ejection amount was calculated from the change amount. <Print Density> Printing was carried out using solid paper using recycled paper for PPC [manufactured by Nippon Kaishi Paper Co., Ltd.], allowed to dry naturally in a room for 24 hours, and then measured its optical density using a Macbeth densitometer R.
D918 (manufactured by Macbeth). <Bleeding> Recycled paper for PPC [manufactured by Nippon Kaishi Paper Co., Ltd.]
After printing an alphanumeric character and leaving it for one hour or more, the sharpness of the character and the degree of mustache-like bleeding generated from the character were evaluated with a microscope and visually. ：: Characters are sharp and have no bleeding blemishes Δ: Characters are not sharp and bleeding occurs a little ×: Characters are not sharp and there are many bleeds <Water-resistant> Recycled paper for PPC [Nippon Kaishi Paper ( Co., Ltd.)
After solid printing, and left for 1 hour or more, it was dipped vertically in still water for 10 seconds and pulled up vertically. After air drying naturally in the room, the optical character density of the solid print portion and the white portion where no print was made was measured with a Macbeth densitometer RD918 (manufactured by Macbeth). <Clogging prevention> After printing alphanumeric characters continuously for 10 minutes with a commercially available Canon micro bubble jet printer (model number BJ-10VL), stop the printer,
It was left for 2 weeks in an environment of 40 ° C. and 25% RH without capping. After the standing, alphanumeric characters were printed again, and the number of clogging recovery operations required until the same printing as before the standing was obtained was examined. ：: Printing equivalent to the initial state is possible with 0 to 2 recovery operations. Δ: Printing equivalent to the initial period is possible with 3 to 5 recovery operations. ×: Printing equivalent to the initial state is not possible even after 6 or more recovery operations. Possible <Fixing property> OHP sheet for inkjet only (MJOH
PS1N, made by Epson), and the eraser (width 18.5mm) is fixed on the printing surface at an inclination of 45 °.
A load of 1 kg was placed thereon, and rubbed five times on the solid printing surface, and the state of the printing surface at that time was visually observed. ：: No scratches or peeling on the print surface △: Scratches on the print surface ×: Scratches on the print surface

Examples 6 to 8 Example 5 was repeated except that the aqueous polyester suspension inks obtained in Examples 2 to 4 were used instead of the aqueous polyester suspension inks obtained in Example 1. In the same manner as in the above, ink for inkjet recording [magenta ink (Example 6), yellow ink (Example 7), black ink (Example 8)] was obtained. The same evaluation as in Example 5 was performed using the obtained ink. Table 1 shows the results.

Comparative Example 1 An ink was obtained from the following formulation using a water-soluble dye commonly used in ink jet recording inks.・ C. I. Acid Yellow 4g Diethylene glycol 7.5g Glycerin 7.5g Water 80.60g Acetyleneol EL 0.40g That is, the above components were mixed for 12 hours using a ball mill, and the resulting dispersion was filtered with a 5 micron filter. To remove dust and coarse particles to obtain an ink. The same evaluation as in Example 5 was performed using the obtained ink. Table 1 shows the results.

[Comparative Example 2] The following ingredients were blended, and a dispersion treatment was carried out using Diminol under the following conditions. <Blending composition>-200 g of carbon black (manufactured by Mitsubishi Kasei, MA-100)-30 g of styrene-maleic anhydride copolymer (acid value 130, number average molecular weight 10,000)-40 g of ethanolamine-200 g of diethylene glycol-50 g of glycerin-pure Water 1420 g-Polyoxyethylene nonylphenyl ether 30 g [Emulgen 985 (trade name) manufactured by Kao Corporation]-Acetyleneol EL 30 g <Dispersion treatment conditions>-Grinding media: titania beads-Grinding media size: φ0.8 mm-Grinding media Filling rate: 80%-Discharge speed: 100 g / min-Number of passes: 8 After dispersion, centrifugation (10000 rpm, 1 rpm)
(5 minutes) to remove coarse particles to obtain an aqueous black ink for inkjet. The same evaluation as in Example 5 was performed using the obtained ink. Table 1 shows the results.

[0079]

[Table 1]

As is evident from the results shown in Table 1, the water-based ink of the embodiment in which the dye or pigment was adsorbed on the polyester suspension had a higher printing than the conventional dye-based ink (Comparative Example 1). It can be seen that the concentration is high and the bleeding prevention and water resistance are further improved.
Further, the printing density is higher and the fixability is higher than that of the conventional pigment-based ink (Comparative Example 2).

[Embodiment 9] The cyan ink, magenta ink, yellow ink obtained in Examples 5 to 8, respectively.
And a color ink set including black ink was set instead of a commercially available ink set (dye-based ink) provided in a commercially available microbubble jet printer (model number BJC-600J) manufactured by Canon Inc., and printing evaluation was performed. As a result, the commercially available ink set was inferior in water resistance, but the color ink set composed of the water-based ink of the present invention reflected the evaluation results in Table 1 above, had a high print density, had low bleeding, had water resistance, Fixing properties have been further improved,
The color reproducibility was good, and the color ink set was also good.

[0082]

According to the water-based ink of the present invention, the print density of the printed matter is high, and the fixability and the water resistance of the printed matter are improved. In particular, when a dye is used, the water resistance of the ink is extremely improved, and bleeding is prevented. When a pigment is used, the fixability of the ink to paper, an OHP sheet, or the like is extremely improved. In addition, by performing the above adsorption by phase inversion emulsification,
Adsorption of dyes and pigments can be performed easily and efficiently, and the water resistance and fixability of the ink are further improved. The above-mentioned water-based ink is particularly useful as a water-based ink for ink-jet recording, and can also be used as ink for writing implements such as general fountain pens, ballpoint pens, and felt-tip pens.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-157508 (JP, A) JP-A-9-100396 (JP, A) JP-A-9-183932 (JP, A) 183931 (JP, A) JP-A-9-217030 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (7)

(57) [Claims] 1. A polyester suspension having a dye or pigment adsorbed thereon, wherein the polyester comprises a diol component represented by the following formula (1), a dimer acid, and a divalent or higher polyvalent carboxylic acid other than the dimer acid. Acid (however, acid component
As a cyclohexene except dicarboxylic acid), water-based ink, characterized in that the one or more components selected from the group consisting of an acid anhydride thereof and lower alkyl esters are those obtained by condensation copolymer. Embedded image 2. JIS K007 of the above polyester
The water-based ink according to claim 1, wherein the acid value based on 0 is 3 to 100 KOHmg / g. 3. The suspension according to claim 1, wherein said suspension has an average particle size of 0.1.
The aqueous ink according to claim 1, wherein the aqueous ink has a thickness of 005 to 0.5 μm. 4. The polyester having a glass transition point of 20
The aqueous ink according to any one of claims 1 to 3, which is at least 0C. 5. The polyester having a number average molecular weight of 50.
The aqueous ink according to any one of claims 1 to 4, wherein the aqueous ink is 0 to 100,000. 6. A water-based ink for ink-jet recording, wherein the water-based ink according to claim 1 is used. 7. A diol component represented by the following formula (1), a dimer acid, and a divalent or higher polyvalent carboxylic acid other than the dimer acid (provided that the acid component is cyclohexenedical).
Excluding Bonn acid), acid value obtained by co-condensation polymerization polyester of 3~100KOHmg / g and one or more components selected from the group consisting of an acid anhydride thereof and lower alkyl esters, dyes or pigments A water-based ink characterized by adding a neutralizing agent to the carboxyl group in the polyester by adding a neutralizing agent, and then adding water, and then distilling off the solvent and inverting the water-based ink. Method. Embedded image