JP2002220558A - Printing liquid and ink-jet printing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing liquid capable of giving printed matter with high gas resistance and light resistance. SOLUTION: This printing liquid contains a water-soluble resin including nonionic structural unit, cationic structural unit and anionic structural unit; wherein a monomer giving the nonionic structural unit is preferably vinyl acetate, N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone, N- vinylcaprolactam, (meth)acrylamide or a (meth)acrylic ester; the cationic structural unit is such as to have a primary amino group, secondary amino group, tertiary amino group, quaternary amino group or a phosphorus-containing cationic group or a salt thereof; and a monomer giving the anionic structural unit is a <=20C, preferably <=15C ethylenically unsaturated bond-bearing compound containing sulfo group, carboxylic acid group, phosphoric acid group or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a recording liquid and an ink jet recording method using the same. More specifically, the present invention relates to a recording liquid that is effective for preventing fading of printed matter created by a recording method such as ink jet recording due to gas, and an ink jet recording method using the same.

[0002]

2. Description of the Related Art Ink jet recording systems are rapidly being used for personal use because of the ease of full-color printing, low noise, the ability to obtain high-resolution images at low cost, and high-speed printing. , And it is becoming popular in both business use. Among the ink jet recording methods, a recording method using an aqueous ink is the mainstream, and at present, a printed matter having a very high resolution has been obtained.

[0003] JP-A-10-324835 discloses that a specific cationic water-soluble resin is added to an alkali-soluble coloring agent, a water-soluble organic solvent, and water to provide excellent water resistance and light resistance, and to prevent bleeding. It is described that an ink composition for inkjet recording having a small amount is obtained. JP-A-10-130555 discloses a long-term storage stability by adding a specific cationic water-soluble resin to an alkali-soluble coloring agent, a water-soluble organic solvent having a lower vapor pressure than water, and water. And obtaining an ink composition for inkjet recording having excellent water resistance.

[0004]

However, recently,
In many cases, printed matter by an ink jet recording method is displayed outdoors as an advertising medium, and higher performance is required in terms of light resistance to sunlight. In addition, the number of cases in which printed matter is displayed on the side of a road has increased, and discoloration of the printed matter due to gas has been regarded as a problem. Therefore, development of an ink jet recording liquid having not only light resistance but also gas resistance has been desired.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a recording liquid containing a water-soluble resin containing a nonionic structural unit and an ionic structural unit has excellent light fastness. The present invention has been found to have excellent gas resistance as well as excellent gas resistance. That is, the gist of the present invention resides in a recording liquid containing a colorant, water, and a water-soluble resin containing a nonionic structural unit and an ionic structural unit.

Another aspect of the present invention resides in an ink jet recording liquid comprising this recording liquid. Yet another aspect of the present invention resides in an ink jet recording method using the recording liquid. Incidentally, the above-mentioned Japanese Patent Application Laid-Open No.
JP-A-324835 describes that, in addition to a specific cationic unit, a specific cationic water-soluble resin can contain various other monomer units and that other water-soluble resins can be used in combination. I have. The same is described in Japanese Patent Application Laid-Open No. 10-130555.

However, as described in the present invention, it is not described that a water-soluble polymer selectively containing a nonionic structural unit and an ionic structural unit is contained in a recording liquid, and the effect thereof is not described. In particular, there is no suggestion about a recording liquid containing a water-soluble polymer containing a hydroxyethylene unit and an aminoethylene unit, which is one of the preferred embodiments of the present invention.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The recording liquid according to the present invention can be used for recording by writing instruments, stamps, printing, and other various methods, and is particularly preferably used as an ink jet recording liquid.

The recording liquid according to the present invention contains a water-soluble resin containing a nonionic structural unit and an ionic structural unit in addition to conventional components such as a colorant and water. It is presumed that the printed matter prepared using the recording liquid according to the present invention has excellent light fastness and gas fastness due to the interaction between the water-soluble resin and the dye. Although the mechanism of the interaction is not clear, the fact that the ionic structural unit in the water-soluble resin interacts with the ionic group contained in the dye, for example, a dye having an anionic group and a cationic It is considered that a certain kind of associated structure is formed by the occurrence of ionic interaction between the cationic structural unit and the water-soluble resin containing the structural unit.

However, if the interaction between the water-soluble resin and the dye molecules is too strong, a strong ion complex may be formed and aggregates or precipitates may be formed in the recording liquid. Since the water-soluble resin used in the present invention has a nonionic structural unit, it moderately relieves the interaction between the dye molecule and the water-soluble resin from becoming too strong, and is used to maintain the recording liquid stably. It is considered to have contributed.

In the recording liquid of the present invention, it is important to use a water-soluble resin containing both a nonionic structural unit and an ionic structural unit in one molecule. Or using a mixture of a water-soluble resin consisting of only a nonionic structural unit and a water-soluble resin consisting of only a cationic structural unit,
It is clear from the fact that the effect as in the present invention cannot be obtained.

The ratio of the nonionic structural unit to the ionic structural unit of the water-soluble resin used in the present invention depends on the type of each structural unit and the ionic group contained in the structure of the dye used. The value may be determined in consideration of stability and light resistance and gas resistance of the obtained printed matter. Usually, the nonionic structural unit in the water-soluble resin is 60 to 99 mol%, and the ionic structural unit is 1 to 40 mol%.

When the content of the nonionic structural unit is less than 60 mol%, light resistance tends to decrease, and precipitates and aggregates tend to be easily formed in the recording liquid. When the amount of the ionic structural unit is less than 1 mol%, the interaction with the dye molecule becomes small. In particular, in the case of the cationic structural unit, the intended effect of improving the gas resistance is hardly exhibited. Generally, in the case of a recording liquid containing a dye having an anionic group, the nonionic structural unit in the water-soluble resin is 70 mol% or more and 99 mol% or less, and the cationic structural unit is 1 mol% or more and 30 mol% or less. It is more preferable that the content of the cationic structural unit is 2 mol% or more. Among them, nonionic structural units are preferably 70 mol% or more, particularly 75 mol% or more and 95 mol% or less, and cationic structural units are 5 mol% or more,
It is 30 mol% or less, especially 25 mol% or less.

The dye having an anionic group means, for example, a sulfonic acid group, a carboxylic acid group, a phosphoric acid group,
And dyes having these salts. Specific examples include those described in direct dyes, acid dyes, reactive dyes, food colorings and the like in the color index. In addition, depending on the type of the dye, it is difficult to adjust to a water-soluble resin having a cationic structural unit, and there is a case where stability is likely to be caused such that an aggregate or a precipitate is easily generated. In such a case, the water-soluble resin is used. By introducing an appropriate anionic structural unit to, to reduce the interaction between the dye molecule and the water-soluble resin,
The recording liquid can be made more stable. In this case, the content of the anionic structural unit is 39 mol% or less, and preferably 29 mol% or less. The lower limit of the content is 0.00
It is 1 mol%, preferably 0.01 mol%. Even within this range, 0.1 to 24 mol%, particularly 0.1 to 10 mol%, is preferable.

By the introduction of the anionic structural unit, the interaction between ions between the anionic group of the dye and the cationic structural unit in the water-soluble resin is reduced, and the recording liquid becomes more stable. In addition, including the case where the above-mentioned dye is an anionic dye, depending on the dye used, particularly its ionicity,
It goes without saying that the amount of the ionic structural units of the water-soluble resin and the types and ratios of the cationic and anionic structural units thereof should be appropriately selected.

Examples of the monomer that gives a nonionic structural unit in the water-soluble resin used in the present invention include vinyl esters such as vinyl acetate, N-vinylformamide, and N-vinylformamide.
Vinyl ethers such as vinyl acetamide, N-vinyl pyrrolidone, N-vinyl caprolactam, N-vinyl succinimide, N-vinyl maleimide, N-vinyl phthalimide, acrylic acid ester, methacrylic acid ester, alkyl vinyl ether, (meth) acrylamide, ( Vinyl compounds having 20 or less, preferably 15 or less carbon atoms, such as (meth) acrylamide derivatives, (meth) acrylonitrile, styrene, ethylene, propylene, isobutylene, vinyl chloride, vinylidene chloride, and allyl ether are used. Sulfur dioxide can also be used.

Preferably, vinyl acetate, N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, (meth) acrylamide and (meth) acrylester are used. Particularly preferably, vinyl acetate, N-vinylformamide, N-
Vinylacetamide. These vinyl compounds may be included in the water-soluble polymer in a modified form after hydrolysis to form a water-soluble polymer. For example, vinyl acetate may be included in the water-soluble polymer in the form of a hydroxyethylene unit or an acetal obtained by modifying the polymer with an aldehyde after hydrolyzing after forming a polymer. Also,
Polyamides such as nylon, polyesters, polyethylene glycol, condensation polymers such as polyethers such as polypropylene glycol, carboxymethyl cellulose,
Cellulosics such as hydroxyethylcellulose and cellulose derivatives, natural polymers such as starch, gelatin, guar gum, xanthan gum, and derivatives thereof can also be used as those which provide nonionic structural units.

The more nonionic structural units, the more
The interaction between the water-soluble resin and the dye in the ink is reduced. The cationic structural unit of the water-soluble resin used in the present invention includes, as a cationic group, a primary amino group, a secondary amino group, a tertiary amino group, a quaternary ammonium group, a phosphorus-containing cationic group, and a salt thereof. Is used. Among them, those having a primary amino group are preferably used. As a monomer that provides these cationic structural units, a vinyl compound having these cationic groups or a vinyl compound that generates these cationic groups by hydrolysis or the like is used. For example, allylamine, diallylamine, vinylpyridine, N-vinylimidazole, vinylbenzylammonium salt, ammonium salt of alkylstyrene, acrylamide-based compound having an amino group, and (meth) acryl having 20 or less carbon atoms, preferably 15 or less carbon atoms Acid ester compounds, N-vinylformamide, N-vinylacetamide and the like are used.

Particularly preferred structural units are aminoethylene units or aminomethylethylene units. The aminoethylene unit can be contained in a water-soluble resin by using N-vinylformamide or N-vinylacetamide as a monomer and hydrolyzing a produced polymer to change an amide group to an amino group. In general, as the number of cationic structural units increases, the gas resistance of a printed matter can be increased. In general, the free amino group in the cationic structural unit has a greater effect of improving the gas resistance of the printed matter, but on the other hand, it may inhibit the action of other components in the recording liquid. In such a case, it is preferable to appropriately neutralize and use in the form of a salt.

For example, hydrochloride, sulfate, formate, acetate, sulfamate, methanesulfonate, lactate, butyrate, nitrate, perchlorate, bromate, hydrofluoride, etc. Used. Examples of the monomer that provides the anionic structural unit of the water-soluble resin used in the present invention include an ethylenic monomer having a carbon number of 20 or less, preferably 15 or less, containing a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, and the like. Compounds having a saturated bond, for example, α, β-unsaturated dicarboxylic acids such as maleic acid and fumaric acid, crotonic acid, cinnamic acid, acrylic acid, methacrylic acid, itaconic acid, vinylsulfonic acid, (meth) allylsulfonic acid , Styrenesulfonic acid, sodium 2-sulfoethyl methacrylate, 2-acrylamide 2-methylpropanesulfonic acid, phosphorus-containing (meth) acrylate, phosphorus-containing acrylamide derivatives, and the like. Preferably, those having a carboxylic acid group are used. Particularly preferred are maleic, fumaric, crotonic, cinnamic, acrylic, methacrylic and itaconic acids.

The monomers providing these anionic structural units may be used in the form of a salt. For example, sodium salt,
It can be used as potassium salt, calcium salt, lithium salt, magnesium salt, barium salt, ammonium salt and the like. In the present invention, a water-soluble resin composed of the above-mentioned various ionic structural units and nonionic structural units can be used. Usually, an acetyloxyethylene unit and a formamide ethylene unit (—CH ₂ —CH (NHCH)
O)-) and nonionic constituent units selected from hydroxyethylene units in a total amount of 60 to 99 mol%, preferably 70 to 99 mol% (however, acetyloxyethylene units have a low solubility in water and are therefore used alone. The content of this structural unit in the water-soluble resin is usually 50 mol% or less, preferably 0.01 mol% or more and 40 mol or less so as not to impair the water solubility of the resin. % Or less), and a water-soluble resin containing 1 to 40 mol%, preferably 1 to 30 mol% of aminoethylene units of the cationic structural unit.

Among them, hydroxyethylene units of 70 to
It is preferable to use one containing 99 mol% (preferably 70 to 95 mol%, more preferably 70 to 90 mol%). More preferably, the content of the hydroxyethylene unit is 75 mol% or more, particularly preferably 80 mol% or more. The content of the aminoethylene unit combined with the hydroxyethylene unit is preferably 5 to 30 mol%, more preferably 10 to 30 mol%.
In particular, it is more preferably at most 20 mol%.

The amino group of the aminoethylene unit may be in the form of a neutralized salt, for example, hydrochloride, sulfate, formate, acetate, sulfamate, methanesulfonate, lactate, butyric acid Salt, nitrate, perchlorate, bromate,
It may be present in the water-soluble resin as a hydrofluoric acid salt or the like. The water-soluble resin having a nonionic structural unit selected from the acetyloxyethylene unit, formamidoethylene unit and hydroxyethylene unit and an aminoethylene unit as a cationic structural unit includes vinyl acetate and N
-Copolymerization with vinylformamide by a known method,
It can be produced by hydrolyzing the product.

As the polymerization method, any method such as ionic polymerization such as anionic polymerization and cationic polymerization or radical polymerization may be used, but radical polymerization is preferred because the molecular weight of the copolymer can be easily controlled. As a polymerization initiator for radical polymerization, any of the usual general initiators can be used, but an azo compound is preferable in order to obtain a copolymer with a high yield. Particularly preferred initiators are 2,2 '
Azobis-4-amidinopropane hydrochloride and acetate, 4,4'-azobis-4-cyanovaleric acid sodium salt, azobis-N, N'-dimethyleneisobutylamidine hydrochloride and sulfate. . The amount of these polymerization initiators used is usually 0.0
1 to 1% by weight.

The polymerization can be carried out by known methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. The polymerization reaction is generally carried out under an inert gas stream, usually from 30 to 100.
It is performed under a temperature condition of ° C. In the case of solution polymerization, water is used as a solvent, and the polymerization is usually carried out with an aqueous solution having a monomer concentration of 5 to 60% by weight. In the case of suspension polymerization, the monomer concentration is usually 20 to 20% by weight.
An 80% by weight aqueous solution is polymerized in a water-in-oil type dispersion using a hydrophobic solvent and a dispersion stabilizer. Emulsion polymerization is usually
An aqueous solution having a monomer concentration of 20 to 60% by weight is prepared in an oil-in-water or water-in-oil type emulsified state using a hydrophobic solvent and an emulsifier.

The hydrolysis of the resulting copolymer is generally carried out by
It is carried out under acidic or basic conditions. The acidic hydrolysis is performed using, for example, a strong acid such as hydrochloric acid, bromic acid, hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid, sulfamic acid, and methanesulfonic acid. Multivalent acids are preferred. In the case of acidic hydrolysis, since the amino group in the polymer formed by hydrolysis is in the form of a salt, it is treated with an alkali to adjust the amount of free amino group to a desired value.

The basic hydrolysis is carried out using a strong base such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and quaternary ammonium hydroxide.
Sodium hydroxide is preferred. The amount of the modifier used for the hydrolysis is N-vinylformamide group in the copolymer,
The amount is usually adjusted appropriately in the range of 0.7 to 5 moles per mole of the vinyl acetate group in accordance with the desired modification rate. The reaction temperature is usually in the range of 50 to 110 ° C, and the reaction time is usually 1 to 1.
8 hours range.

During the hydrolysis, hydroxylamine hydrochloride is optionally added to prevent gelation caused by impurities.
Hydrolysis may be performed by adding a gelling inhibitor such as hydroxylamine sulfate. After the treatment with the gelling inhibitor, the hydrolysis can be carried out. The hydrolysis can be performed in either a homogeneous solution system or a heterogeneous solution system. In the hydrolysis of a homogeneous solution system, for example, a solvent such as water or a mixed solvent of water and methanol is used. In the case of a heterogeneous system, for example, a solvent such as hexane or toluene is used.

In the case of synthesizing a water-soluble resin having a cationic structural unit and an anionic structural unit as the ionic structural unit, when a polymer having a nonionic structural unit and a latent cationic structural unit is polymerized, A method of copolymerizing an anionic monomer or a method of introducing an anionic group into a polymer having a nonionic structural unit and a cationic structural unit by a post-reaction is used.

The molecular weight of the water-soluble resin used in the present invention is 5
00 to 1,000,000 is preferred. More preferably 800 to 200,000, particularly preferably 1,000 to 200.
100,000. If the molecular weight is too high, the viscosity of the recording liquid increases due to its viscosity, and it becomes difficult to perform ejection by an ink jet method. If the molecular weight is too small, the desired effect cannot be obtained. The viscosity of the water-soluble resin is such that the rotational viscosity measured at 25 ° C. as a 4% aqueous solution is 1 to 10,000 mPa.
S, particularly preferably 1 to 1,000 mPa · s. The water-soluble resin is usually contained in the recording liquid in an amount of 0.1% by weight to
Although it is contained so as to be 0% by weight, it is preferably contained in an amount of 20% by weight or less, particularly 10% by weight or less so that the viscosity of the recording liquid does not become too high. Further, the lower limit of the content is preferably 0.2% by weight, particularly preferably 1% by weight so that the desired effect is sufficiently exhibited.

The recording liquid according to the present invention can contain another water-soluble resin as long as the effect of the above-mentioned water-soluble resin is not hindered. By the addition of another water-soluble resin, the formation of aggregates and precipitates during storage of the recording liquid can be suppressed, and the recording liquid can be further stabilized. The content in the recording liquid is usually 10% by weight or less, preferably 5% by weight or less so as not to impair the solubility of other additives. Examples of such water-soluble resins include polymers such as (meth) acrylonitrile, (meth) acrylamide, N-substituted (meth) acrylates, (meth) acrylates, vinyl esters, vinyl ethers, and the like. A nonionic water-soluble resin which is a modified product;
Anionic water-soluble polymers such as (meth) acrylic acid, α, β-unsaturated dicarboxylic acid, sulfoalkyl (meth) acrylamide, sulfoalkyl (meth) acrylate, (meth) allylsulfonic acid, and salts thereof Resin;
(A cationic water-soluble resin which is a polymer such as dialkylaminoalkyl (meth) acrylate, dialkylaminoalkyl (meth) acrylamide, allylamine, diallylamine, and salts or quaternary ammonium compounds thereof is used. Water-soluble resin, for example, polyacrylamide, polymethacrylic acid hydroxyester such as polyhydroxyethyl methacrylate, polyvinylpyrrolidone, polyvinyl alcohol,
It is preferable to use polyethylene glycol, polypropylene glycol or the like.

The coloring agent contained in the recording liquid according to the present invention is:
Any of a dye and a pigment may be used. The colorant is contained in the recording liquid in an amount of about 0.1 to 15% by weight, preferably about 0.5 to 10% by weight, and particularly preferably about 0.5 to 8% by weight. Preferably, an organic dye or pigment is used. As dyes, acid dyes in the color index,
Those described as direct dyes, reactive dyes, food colorants and the like are preferable.

Examples of dyes used in the recording liquid according to the present invention include yellow dyes such as C.I. I. Acid Yellow 1,
3, 7, 11, 17, 19, 23, 25, 29, 36,
38, 40, 42, 44, 49, 59, 61, 65, 7
0, 72, 75, 76, 78, 79, 98, 99, 10
4,110,111,127,131,135,14
2,155,162,165,183,194, C.I.
I. Direct Yellow 1,8,11,12,24,2
6,27,33,39,44,50,55,58,8
5,86,87,88,89,98,106,110,
132, 142, 144, 173, 194C. I. Reactive Yellow 1,2,3,4,6,7,11,1
2,13,14,15,16,17,18,22,2
3, 24, 25, 26, 27, 37, 42, and their hydrolysates, C.I. I. Food Yellow 3, 4, C.I.
I. Solvent Yellow 15, 19, 21, 30, 10
9 and the like. Further, as the red system, C.I. I. Acid Red 1,6,8,9,13,14,18,2
6,27,32,35,37,42,49,50,5
1,52,57,75,77,80,82,83,8
5,87,88,89,92,93,94,95,9
7, 98, 106, 111, 114, 115, 117,
118, 119, 129, 130, 131, 133, 1
34,138,143,145,154,155,15
8,168,180,183,184,186,19
4,198,209, 211,215,219,24
9,252,254,262,265,274,28
2,287,289,303,306,317,32
0, 321, 322, 356, C.I. I. Direct Red 1,2,4,9,11,13,17,20,23,2
4,28,31,33,37,39,44,46,6
2,63,75,79,80,81,83,84,8
9,95,99,113,197,201,218,2
20,224,225,226,227,228,22
9, 230, 231, C.I. I. Reactive Red 1,
2,3,4,5,6,7,8,11,12,13,1
5,16,17,19,20,21,22,23,2
4,28,29,31,32,33,34,35,3
6,37,38,39,40,41,42,43,4
5, 46, 49, 50, 58, 59, 63, 64, 18
0, and their hydrolysates, C.I. I. Sorbize Red 1, C.I. I. Food Red 7, 9, 14 and the like. Further, C.I. I. Acid Violet 15, 31,
34, 41, 43, 48, 49, 51, C.I. I. Direct violet 107 is also included. Further, as a blue color, C.I. I. Acid Blue 1,7,9,15,2
2,23,25,27,29,40,41,43,4
5,54,59,60,62,72,74,78,8
0, 82, 83, 90, 92, 93, 100, 102,
103, 104, 112, 113, 117, 120, 1
26, 127, 129, 130, 131, 138, 14
0,142,143,151,154,158,16
1,166,167,168,170,171,18
2,183,184,187,192,199,20
2,203,204,205,229,234,23
6,249, C.I. I. Direct Blue 1, 2, 6, 1
5, 22, 25, 41, 71, 76, 77, 78, 8
0,86,87,90,98,106,108,12
0,123,158,160,163,165,16
8,192,193,194,195,196,19
9,200,201,202,203,207,22
5,226,236,237,246,248,24
9, C.I. I. Reactive Blue 1,2,3,4,5
7, 8, 9, 13, 14, 15, 17, 18, 19, 2
0, 21, 25, 26, 27, 28, 29, 31, 3
2,33,34,37,38,39,40,41,4
3, 44, 46 and their hydrolysates, C.I. I. Solubiliz Bat Blue 1, 5, 41, C.I. I. Bat Blue 29, C.I. I. Food Blue 1, 2, C.I. I Basic Blue 9, 25, 28, 29, 44 and the like. Further, C.I. I. Acid Green 3,5,9,1
6, 25, 27, 36, 40, 41, 44, C.I. I. Reactive Green 7 and the like. C.I. I.
Acid Brown 13, 27, 103 and the like.
Further, C.I. I. Acid Black 1,
2, 7, 24, 26, 29, 31, 48, 50, 51,
52, 58, 60, 62, 63, 64, 67, 72, 7
6,77,94,107,108,109,110,1
12, 115, 118, 119, 121, 122, 13
2,139,140,155,156,157,15
8, 159, 191, C.I. I. Direct Black 1
7, 19, 22, 32, 35, 38, 51, 56, 6
2,71,74,75,77,94,105,106,
107, 108, 112, 113, 117, 118, 1
32,133,146,154,168,171,19
5,200, C.I. I. Reactive Black 1,3
4, 5, 6, 8, 9, 10, 12, 13, 14, 18,
31, and their hydrolysates, C.I. I. Solubiliz Bat Black 1, C.I. I. Food Black 2 and the like. In addition to the dyes described in these color indexes, dyes having a basic skeleton shown in Table 1 below are also preferably used. In addition, R described in each of the general formulas in Table 1 independently represents a hydrogen atom, a halogen atom, or any other substituent, and may be a substituent containing a dye structure in each of the general formulas. good. When a plurality of Rs are described in the general formula, they may be different or the same. R 'represents a linking group.

[0034]

[Table 1] When a pigment is used as the colorant, those described in the pigment of the color index are generally suitable. For example, C.I. I. Pigment Yellow 17, 23, 74, 93,
128, C.I. I. Pigment Red 41, 48, 54,
57, 58, 63, 68, 81, 122, C.I. I. Pigment Blue 1, 15, 17 and carbon black can be used.

These coloring agents can be used alone or
Mixtures of more than one type can also be used. Among these colorants, acid dyes, direct dyes, reactive dyes, and food dyes are preferable, and dyes having an anionic group are particularly preferable. The anionic group of the anionic dye is a sulfonic acid group,
Any of a carboxylic acid group, a phosphoric acid group, and a salt thereof may be used. The number of anionic groups in one molecule is usually 1 to 8.

The recording liquid according to the present invention may contain a water-soluble organic solvent. Usually, an organic solvent having a lower vapor pressure than water is used. Some examples are ethylene glycol, propylene glycol, butanediol, pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, 1,2,6-hexanetriol, diethylene glycol. Polyhydric alcohols such as triethylene glycol, polyethylene glycol (weight average molecular weight 190 to 400), glycerin, dipropylene glycol,
Ketones such as acetonylacetone; esters such as γ-butyrolactone, diacetin, and triethyl phosphate;
-Methoxyethanol, lower alkoxy alcohols such as 2-ethoxyethanol, furfuryl alcohol, tetrahydrofurfuryl alcohol, N-methylpyrrolidone, N-ethylpyrrolidone, 1,3-dimethylimidazolidinone, thiodiethanol, thiodiglycol, Dimethyl sulfoxide, ethylene glycol monoallyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, 2-pyrrolidone, sulfolane,
Imidazole, methylimidazole, hydroxyimidazole, triazole, nicotinamide, dimethylaminopyridine, ε-caprolactam, lactamide, 1,3
-Propane sultone, methyl carbamate, ethyl carbamate, 1-methylol-5,5-dimethylhydantoin, hydroxyethylpiperazine, piperazine, ethylene urea, propylene urea, urea, thiourea, biuret, semicarbazide, ethylene carbonate, propylene carbonate,
Acetamide, formamide, dimethylformamide,
N-methylformamide, dimethylacetamide and the like can be mentioned. These water-soluble organic solvents are usually contained in the recording liquid in a range of 1 to 45% by weight, preferably 1 to 40% by weight.

On the other hand, water is contained in the recording liquid in the range of 45 to 99% by weight, preferably 50 to 95% by weight.
The recording liquid according to the present invention may contain various conventional auxiliaries as needed. Examples of such an auxiliary include a penetration enhancer, a viscosity adjuster, a surface tension adjuster, a hydrotrope, a humectant, a pH adjuster, a fungicide,
Chelating agents, preservatives, rust inhibitors and the like can be mentioned.

The above-mentioned water-soluble organic solvent may play the role of these auxiliaries, and the two cannot be clearly distinguished. However, the auxiliaries are usually contained in the recording liquid in an amount of about 40% by weight or less.
Preferably, it is contained so as to be about 35% by weight or less. Examples of the penetration enhancer include lower alcohols such as ethanol, isopropanol, butanol and pentanol, carbitols such as ethylene glycol monobutyl ether and triethylene glycol monobutyl ether glycol ether, and surfactants.

As the surfactant, a nonionic surfactant is preferable, but an anionic surfactant can also be used. Examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene derivatives, oxyethylene / oxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid Esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines and the like are used.

Examples of the anionic surfactants include fatty acid salts, alkyl sulfate salts, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfosuccinates, alkyl diphenyl ether sulfonates, alkyl phosphates, polyoxygen salts and the like. Ethylene alkyl sulfates, polyoxyethylene alkylaryl sulfates, alkane sulfonates, naphthalene sulfonate formalin condensates, polyoxyethylene alkyl phosphates, α-olefin sulfonates and the like are used.

Examples of the polymer surfactant include polyacrylic acid, styrene / acrylic acid copolymer, styrene / acrylic acid / acrylate copolymer, styrene / maleic acid copolymer, and styrene / maleic acid / acrylic acid. Acid ester copolymer, styrene / methacrylic acid copolymer, styrene / methacrylic acid / acrylic acid ester copolymer, styrene / maleic acid half ester copolymer,
A styrene / styrene sulfonic acid copolymer, a vinyl naphthalene / maleic acid copolymer, a vinyl naphthalene / acrylic acid copolymer or a salt thereof is used.

By adding 0.001 to 5.0% by weight of a surfactant, the quick drying property after printing and the printing quality can be further improved. As the surface tension modifier, alcohols such as diethanolamine, triethanolamine, glycerin and diethylene glycol, nonionic, cationic, anionic and amphoteric surfactants can be used.

As the hydrotroping agent, urea, alkyl urea, ethylene urea, propylene urea, thiourea, guanidate, halogenated tetraalkyl ammonium and the like are preferable. As the humectant, glycerin, diethylene glycol or the like can be contained as a water-soluble organic solvent. Furthermore, sugars such as maltitol, sorbitol, gluconolactone, and maltose can be contained.

Examples of the pH adjuster include various organic amines such as diethanolamine and triethanolamine;
Inorganic alkali agents such as hydroxides of alkali metals such as sodium hydroxide, lithium hydroxide and potassium hydroxide, organic acid salts such as lithium acetate, organic acids and mineral acids are used.
As the fungicide and preservative, for example, sodium benzoate, potassium sorbate, thiabendazole, benzimidazole, thiabendazole, thiazoflufamide, pyridinethiol oxide, and the like are used.

Examples of the chelating agent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate,
Sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramildiacetate and the like are used. As the rust inhibitor, for example, acid sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropyl ammonium light,
Pentaerythritol tetranitrate, dicyclohexylammonium nitrite and the like are used.

The recording liquid according to the present invention may contain various components as described above, but basically includes a colorant, water, a nonionic structural unit and an ionic structural unit. The composition ratio of the colorant is 0.1 to 15% by weight, and the water-soluble resin containing the nonionic structural unit and the ionic structural unit is 0.1 to 15% by weight.
30% by weight, with the balance being water.

The preferred composition ratio is such that the colorant is 0.5 to 10%.
% By weight, especially 0.5 to 8% by weight, the water-soluble resin containing the nonionic structural unit and the ionic structural unit is 0.2 to 20% by weight, particularly 1 to 20% by weight, with the balance being water. The ink jet recording liquid preferably has a composition in which part of water is replaced by a water-soluble organic solvent having a lower vapor pressure than water. The water-soluble organic solvent having a lower vapor pressure than water is preferably contained in the recording liquid in an amount of 1 to 45% by weight, particularly 1 to 40% by weight.

The method for preparing the recording liquid is not particularly limited. For example, after diluting a water-soluble resin containing a nonionic structural unit and an ionic structural unit with water, an organic solvent and an auxiliary may be added as necessary. It is preferable to adjust the pH by further adding a coloring agent. The printed matter using the recording liquid according to the present invention has good gas resistance as well as light resistance. Therefore, the recording liquid according to the present invention is particularly suitable for producing printed matter posted in a city having a high concentration of an oxidizing gas such as ozone, nitrogen oxides, sulfur oxides, etc., particularly in the vicinity of a high traffic road. ing.

The gas resistance is determined by exposing a printed matter to an ozone atmosphere for a certain time under an ozone atmosphere most correlated with fading in the air.
The degree of the fading can be evaluated by a method represented by a color difference ΔE. The light fastness can be determined by, for example, performing an exposure test using a device such as a xenon fade meter, and expressing the degree of fading by a color difference ΔE. In these evaluation tests, the color difference ΔE indicates that the larger the value, the greater the discoloration and fading. At ΔE15 or more, clear discoloration and fading are recognized, and at 20 or more, considerable discoloration and fading are recognized.

[0050]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples unless it exceeds the gist. In addition, "part" in the examples
Means "parts by weight" unless otherwise specified. Production of the water-soluble resin 1 containing a nonionic structural unit and an ionic structural unit; ・ Polymerization In a 2 L four-necked flask equipped with a stirrer, a nitrogen inlet tube and a cooling tube, 642 g of demineralized water, Amphitol 20BS as a dispersion stabilizer ( 4.48 g of heptane lauryl methylaminoacetate (Kao)
4.48 g of polyethylene glycol (molecular weight: 20,000), 1.48 g of sodium pyrophosphate, 6.3 g of N-vinylformamide, 39.4 g of vinyl acetate and 2,2′-azobis (2,4-dimethylvaleronitrile (sum 0.098 g of a product of Kojun Pharmaceutical Co., Ltd., trade name: V-65) was added, and the mixture was heated with stirring to 65 ° C. White turbidity started, and a mixture of 56.4 g of N-vinylformamide and 355.5 g of vinyl acetate, and V A 5% alcohol solution of -65 (containing 0.88 g of V-65) was added dropwise over 3 hours.
After stirring for 2 hours at 4 ° C., 4 g of a 5% methanol solution of N, N′-azobisisobutyronitrile and 270 g of demineralized water
Was added. After further stirring for 3 hours, 4 g of a 5% methanol solution of N, N'-azobisisobutyronitrile was added, and the mixture was stirred at 98 ° C for 1 hour to obtain a white paste. When the conversion was measured by liquid chromatography,
99.6% vinylformamide, 9 vinyl acetate
It was 9.4%.

The total charge ratio of N-vinylformamide and vinyl acetate was 15:85 (mole). Hydrolysis 16.45 g of a 30% aqueous solution of hydroxylamine sulfate was added to 1050 g of the white paste obtained above.
Stirred at 0 ° C. for 2 hours. Subsequently, 367.4 g of a 48% aqueous solution of caustic soda was added at 20 ° C. over 1 hour under rapid stirring. The temperature was raised and the mixture was stirred at 75 ° C. for 6 hours.
Stirred at C for 2 hours. The reaction turned into a white slurry. After cooling, the mixture was filtered using a glass filter to obtain a crude polyvinylamine-polyvinyl alcohol polymer. -Purification of polymer The crude polyvinylamine-polyvinyl alcohol copolymer was washed with 1800 g of methanol, and then dried to obtain 223 g of a white polymer powder. The yield was 93%.

As a result of analysis by NMR, it was confirmed that 95% or more of both the vinyl acetate unit and the vinyl formamide unit were hydrolyzed. The cation equivalent of the resin determined by Koroit titration was 3.47 meq / g, and the viscosity of a 4% aqueous solution was 30.6 mPa.
・ S. In addition, as a result of analysis by ion chromatography, residual acetate ions in the polymer (in terms of sodium acetate)
Was 0.2%, and no formate ion was detected.

The obtained water-soluble resin 1 had a nonionic structural unit of 86%, a cationic structural unit of 14%, and a weight average molecular weight by GPC of 5 × 10 ⁴ . Preparation of water-soluble resin 2 containing nonionic structural unit and ionic structural unit; the initial charge was 1.9 g of N-vinylformamide, 4.4 g of vinyl acetate, and the second addition amount was 17.17 g of N-vinylformamide. 2 g, vinyl acetate 39
Polymerization, hydrolysis and purification were carried out in the same manner as in the production example of the water-soluble resin 1, except that the amount was 0.5 g.

The obtained water-soluble resin 2 had a cation equivalent of 32 meq / g, a viscosity of a 4% aqueous solution of 65.7 mPa · s, a nonionic structural unit of 95%, and a cationic structural unit determined by a Koroit titration method. Was 5%, and the weight average molecular weight by GPC was 1 × 10 ⁵ . Example 1 0.8 parts of the above water-soluble resin 1 was used. I. 0.75 parts of Direct Blue 199 and distilled water in total
The mixture was mixed so as to be 00 parts by weight, and the pH was adjusted to 9.5 to obtain a recording liquid.

Example 2 0.8 parts of the above water-soluble resin 2 was used. I. 0.75 parts of Direct Blue 199 and distilled water in total
The mixture was mixed so as to be 00 parts by weight, and the pH was adjusted to 9.5 to obtain a recording liquid. Comparative Example 1 A recording liquid was prepared in the same manner as in Example 1 except that the water-soluble resin was not used.

Comparative Example 2 A recording liquid was prepared in the same manner as in Example 1, except that 0.8 parts of polyvinylamine (weight average molecular weight by GPC: 7 × 10 ⁴ ) was used instead of the water-soluble resin 1. Comparative Example 3 A recording liquid was prepared in the same manner as in Example 1 except that instead of the water-soluble resin 1, 0.8 parts of polyvinyl alcohol (Kuraray Co., Ltd., Kuraray Poval PVA117) was used.

Comparative Example 4 A recording liquid was prepared in the same manner as in Example 1 except that 0.11 part of polyvinylamine and 0.69 part of polyvinyl alcohol were used in place of the water-soluble resin 1. ● Performance evaluation test of recording liquid Printed matter prepared by the ink jet recording method using the recording liquid prepared above was evaluated by the following method, and the results are shown in Table-2.

A solid image was printed using HG4800 manufactured by Seiko Epson as a printer.
The recording liquid was filtered with a 1 μm filter and used for evaluation. A commercially available coated paper (MJA4SP1 manufactured by Seiko Epson Corporation) was used as the recording paper. (A) Optical density Measured with SpectroEye manufactured by Gretag Macbeth (b) Gas resistance of recorded image The recorded image was held for 2 hours in an atmosphere of 3 ppm ozone,
Discoloration was measured with the spectroeye described above. (C) Light fastness of recorded image The recorded image was irradiated with a Xenon fade meter Ci4000 (manufactured by Atlas) for 80 hours, and the fading was measured with the above spectroeye.

Both the gas fastness and the light fastness indicate a color difference due to fading.
E is preferably 15 or less, particularly preferably 13 or less.

[0060]

[Table 2] In the table, * indicates that precipitation occurred in the recording solution and could not be evaluated because it could not be filtered with a 1 μm filter.

[0061]

According to the present invention, the gas resistance and the light resistance of a printed matter can be simultaneously improved by including a water-soluble resin containing a nonionic structural unit and an ionic structural unit in a recording liquid. .

Continued on the front page F-term (reference) 2C056 EA13 FC01 FC02 2H086 BA01 BA52 BA53 BA57 BA59 BA60 BA62 4J039 AD03 AD06 AD08 AD09 AD10 AD12 AD13 AD14 AD23 AE07 BC06 BC07 BC09 BC10 BC11 BC16 BC19 BC20 BC31 BC36 BC50 BC54 BC56 BE01 BE02 BE03 BE03 CA03 CA06 EA35 EA40 GA07 GA24

Claims (22)

[Claims] 1. A recording liquid comprising a colorant, an aqueous medium, and a water-soluble resin containing a nonionic structural unit and an ionic structural unit. 2. The recording liquid according to claim 1, wherein the ionic structural unit contains both a cationic structural unit and an anionic structural unit. 3. The water-soluble resin contains 6 nonionic structural units.
3. The recording liquid according to claim 1, comprising 0 to 99 mol% and an ionic structural unit of 1 to 40 mol%. 4. The water-soluble resin contains 6 nonionic structural units.
0 to 99 mol%, 1 to 40 mol% of a cationic structural unit
The recording liquid according to claim 1, wherein the recording liquid is contained. 5. The cationic group of a cationic structural unit,
The recording liquid according to claim 4, which is a primary amino group or a salt thereof. 6. The cationic structural unit according to claim 4, wherein the cationic structural unit is selected from the group consisting of aminoethylene units, aminomethylethylene units and salts thereof.
The recording liquid according to 1. 7. An anionic structural unit having an anionic group,
The recording liquid according to any one of claims 2 to 6, wherein the recording liquid is a carboxylic acid group or a salt thereof. 8. The anionic structural unit is derived from a member selected from the group consisting of maleic acid, fumaric acid, crotonic acid, acrylic acid, methacrylic acid, itaconic acid and a compound which gives these carboxylic acids by hydrolysis. The recording liquid according to claim 7, wherein: 9. The nonionic structural unit is vinyl acetate, N
-Vinylformamide, N-vinylacetamide, N-
9. The recording liquid according to claim 1, wherein the recording liquid is derived from one selected from the group consisting of vinylpyrrolidone, N-vinylcaprolactam, (meth) acrylamide and (meth) acrylester. 10. The recording liquid according to claim 1, wherein the nonionic structural unit is a hydroxyethylene unit or an acetalized product thereof. 11. The water-soluble resin may have a total of 60 to 99 mol% of structural units selected from acetyloxyethylene units, formylaminoethylene units, and hydroxyethylene units (however, it is possible that acetyloxyethylene units are used alone). No) and 1 to 40 aminoethylene units
The recording liquid according to claim 1, wherein the recording liquid is a polymer and / or a salt thereof containing mol%. 12. The water-soluble resin contains 70 to 99 mol% of hydroxyethylene units and 1 to 3 of aminoethylene units.
The recording liquid according to claim 1, wherein the recording liquid is a polymer and / or a salt thereof containing 0 mol%. 13. The water-soluble resin is a hydrolyzate of a copolymer of N-vinylformamide and vinyl acetate and contains 70 to 99 mol% of hydroxyethylene units and 1 to 30 mol% of aminoethylene units. The recording liquid according to claim 1, wherein the recording liquid is a polymer or a salt thereof. 14. The water-soluble resin having a molecular weight of 500 to 10
00000.
The recording liquid according to any one of the above. 15. A recording solution containing 0.1 to 30 water-soluble resins.
The recording liquid according to any one of claims 1 to 14, wherein the recording liquid is contained by weight%. 16. The recording liquid according to claim 1, wherein the recording liquid contains a water-soluble resin in an amount of 1 to 20% by weight. 17. The recording liquid according to claim 1, wherein the colorant is a dye and / or a pigment. 18. The recording liquid according to claim 1, wherein the colorant is a dye having an anionic group. 19. The recording liquid according to claim 18, wherein the dye having an anionic group has a partial structure selected from sulfonic acid, carboxylic acid, phosphoric acid, and salts thereof. 20. The recording liquid according to claim 1, further comprising a water-soluble organic solvent having a lower vapor pressure than water. 21. An ink jet recording liquid comprising the recording liquid according to claim 1. Description: 22. An ink jet recording method using the ink jet recording liquid according to claim 21.