JP6111989B2 - Inkjet cleaning solution - Google Patents

Description

  The present invention relates to an inkjet cleaning liquid and an ink set that are preferably used in an inkjet printer.

  Inkjet printers have been widely commercialized in recent years as low-noise, high-speed, high-resolution non-impact printers. As the solvent of the ink used for the ink jet printer, water and water-based ink using a water-soluble organic solvent are mainly used from the viewpoint of odor and safety. In addition, water-soluble dyes have been used as the coloring material, but have the disadvantage of being inferior in light resistance and ozone fading resistance. Accordingly, studies have been made on pigment inks that use pigments instead of water-soluble dyes.

  Aqueous pigment ink is a pigment dispersed in an aqueous medium in the form of fine particles, and because the pigment itself has high light resistance and ozone fading resistance, the storage stability of the obtained image is compared with that using a dye. Can be significantly increased. For this reason, practical use of ink jet printers using pigment inks has progressed as large format printers in the sign display market. In recent years, pigment inks have also begun to be used in line pass type ink jet printers that can print at a high speed while a base material is continuously flowed with an ink jet head fixed.

  However, in the ink using the pigment, when the ink adhering to the vicinity of the discharge port (nozzle) of the inkjet head is dried, unlike the dye, the dispersed pigment particles are aggregated and fixed, causing the nozzle to be clogged. Causes non-ejection of ink. In addition to the head, when the ink is dried and fixed on the cap, the wipe portion, etc., there is a problem that wiping becomes difficult and the maintenance is burdened. Various measures are taken to deal with such a situation.

  As a countermeasure for preventing the ink from being clogged at the ejection port, a technique of covering the ejection port with a cap when the ink jet printer is not performing an image recording operation is recorded in Patent Document 1. However, if the printer is not used for a long period of time, the solvent will evaporate, the ink viscosity near the nozzle will increase, clogging may occur, and clogging may occur due to foreign matter such as dust in the outside air. This was the cause of ink ejection failure. As measures to prevent this problem, a cleaning method is used to clean the inside of the ink flow path when a problem occurs, and a method of replacing the ink with a cleaning solution in advance when a long-term apparatus pause is assumed. ing.

  Examples of the cleaning liquid or cleaning liquid or maintenance liquid include a maintenance liquid containing a plasticizer and a humectant described in Patent Document 2, a cleaning liquid containing a basic compound and a surfactant described in Patent Document 3, Examples include a maintenance liquid containing a basic compound and an acidic compound, a cleaning liquid containing a surfactant and a basic compound described in Patent Document 5 and having a pH of 9 or more, and an alkylene glycol monoalkyl ether-containing cleaning liquid described in Patent Document 6. .

JP 59-111856 A JP 2008-214525 A JP 2010-235712 A JP 2011-68085 A JP 2000-127419 A Japanese Patent Laid-Open No. 2005-7703

  However, the above cleaning liquid, cleaning liquid or maintenance liquid is inferior in the ability to re-disperse the agglomerated pigment particles with respect to the water-based pigment ink described above, and the pH is too high to damage or fix the device members. There is a problem that the pigment dispersion of the ink which is not present is broken to cause agglomeration, resulting in a serious reliability problem such as nozzle clogging.

  The present invention has been made in view of the above, and an object of the present invention is to provide an inkjet cleaning liquid that is excellent in the ability to re-disperse dried and agglomerated pigment particles in an inkjet printer using pigment ink.

The above object is achieved by the present invention described below. That is,
Containing at least water, an organic solvent, a resin having an acidic functional group, and a cationic agent,
The resin having an acidic functional group has an aromatic ring in a resin skeleton and is neutralized with a cationic agent.

The present invention also relates to an inkjet cleaning liquid, wherein the content of the cationic agent in the cleaning liquid is 0.8 or more.
[Formula 1]
Amount of basic functional group of cationic agent in cleaning solution [mmol] / Amount of acidic functional group of resin in cleaning solution [mmol]

  The present invention also relates to an inkjet cleaning liquid comprising at least one water-soluble organic solvent having a boiling point of 200 ° C. or higher as the organic solvent.

  The present invention also relates to an inkjet cleaning liquid, wherein the inkjet cleaning liquid has a pH of 7.0 or more and 10.0 or less.

The present invention also relates to an ink jet cleaning liquid and an ink set comprising the ink jet cleaning liquid and an ink jet ink containing a pigment as a colorant.
In the present invention, the ink contains a pigment dispersion resin,
The pigment dispersion resin contains the same resin as the resin having an acidic functional group in the inkjet cleaning liquid, and relates to the ink jet cleaning liquid and ink set.

  ADVANTAGE OF THE INVENTION According to this invention, the inkjet cleaning liquid which is excellent also in the ability to re-disperse the dry and aggregated pigment particle can be provided also in the ink jet printer which uses water-based pigment ink.

  Next, the present invention will be described in detail. Unless otherwise specified, “part” represents “part by weight” and “%” represents “% by weight”.

Cleaning solution:
The cleaning liquid for inkjet recording of the present invention contains water, an organic solvent, a resin having an acidic functional group, and a cation agent, and the resin having the acidic functional group is neutralized with the cation agent, so that the liquid medium contains It exists in a dissolved state. This cleaning liquid has the ability to redisperse the aggregated and fixed pigment particles, adheres to the nozzle surface of the inkjet head, the flow path, the wiper blade and the cap, and disperses and cleans the aggregated and fixed pigment ink. Can do. Further, by controlling the pH to be weakly alkaline, there is no risk of damaging various members of the apparatus or causing dispersion and aggregation when mixed with pigment ink.

  Pigments are generally insoluble in water, but by using a dispersant having a hydrophilic functional group, or by modifying the pigment surface with a hydrophilic functional group, the surface becomes hydrophilic and fine. It can be dispersed in water as particles. The most common hydrophilic functional group is an acidic functional group.

  When the hydrophilicity of the pigment surface is broken, the pigment particles are not dispersed and cause aggregation. For example, when the ionization balance of the surface functional groups is broken by a strong acidic substance or a strong alkaline substance, or the water evaporates by drying, the pigment dispersed in the water and the solvent is aggregated and fixed. . The pigment thus agglomerated and fixed agglomerates very firmly and is generally difficult to remove by washing.

  Therefore, the present inventors have found that a pigment containing a resin having an acidic functional group neutralized by a cationic agent can easily wash the pigment that has been agglomerated and fixed in this way. This is because the resin in the cleaning liquid adheres to the pigment surface on which the agglomeration is fixed and can be dispersed again.

  In addition, it is desirable that the cleaning liquid contains a cation agent in excess of the resin neutralization amount in order to compensate for the neutralizing agent lost from the acidic functional group on the pigment surface. Originally, when an excess of the cationic agent is contained, the pH rises and the alkaline cleaning solution becomes strong and there is a high risk of damaging the printer member. However, the cleaning solution in the present invention is neutralized with the cationic agent. A resin having an acidic functional group works as a pH buffer, and even if an excessive cationic agent is added, the pH is hardly increased and can be suppressed to weak alkalinity.

  In addition, when the cleaning liquid containing such a water-soluble resin is dried, the resin may be dry-fixed, which may cause problems such as clogging. Therefore, the cleaning liquid contains a moisturizing agent. It is desirable to use a water-soluble solvent having a high boiling point.

  The cleaning liquid for inkjet recording of the present invention will be described below with reference to preferred embodiments.

  The resin having an acidic functional group used in the present invention is a resin that is water-soluble by being neutralized with a cationic agent. Examples of the resin having an acidic functional group include an acrylic resin, a styrene acrylic resin, a maleic acid resin, a styrene maleic resin, an α-olefin maleic resin, a urethane resin, and an ester resin. Any resin can be used as long as it is water-soluble when neutralized with a cationic agent.

  The resin used in the present invention preferably has pigment dispersibility. By having the pigment dispersing ability, it is possible to easily redisperse the agglomerated and fixed pigment. Specifically, those having an aromatic ring in the resin skeleton are preferable because of high pigment dispersibility. Since the aromatic ring skeleton and the pigment skeleton interact with each other by the π-π interaction, the adsorption force of the resin to the pigment increases, so that the resin has a pigment dispersing ability. Examples of the aromatic ring skeleton include hydrocarbon aromatic groups such as phenyl group and naphthyl group, and heteroaromatic groups such as furyl group and imidazole group.

  The acid value of the resin used in the present invention is not particularly limited. However, an acid value that is too low is preferably less than 50 mg KOH / g because the solubility in water is low. It is preferable to have it. More preferably, it has an acid value of 100 mgKOH / g or more. Further, the molecular weight of the resin used in the present invention is not particularly limited, but the resin having a molecular weight that is too high preferably has a weight average molecular weight of 50,000 or less because the solubility in water becomes low. It is preferable. More preferably, it has a weight average molecular weight of 30,000 or less.

  The cationic agent used for neutralization in the present invention refers to a compound having a basic functional group. The cationic agent is not particularly limited, but from the viewpoint of being used for the neutralization of the resin, if the molecular weight is too large, the viscosity becomes high or the resin is not neutralized well. For this reason, low molecular weight compounds are preferred. For example, organic cation agents such as ethanolamine, diethanolamine, triethanolamine, and dimethylaminoethanol, alkali metal hydroxides such as sodium hydroxide, inorganic cation agents such as ammonia, and the like can be used. Of these, low boiling point cation agents easily evaporate and lose their neutralizing ability. Therefore, it is preferable to use a cation agent having a relatively high boiling point, such as diethanolamine, triethanolamine, dimethylaminoethanol, hydroxylation. Sodium is preferably used. Moreover, it is preferable to use a weakly basic cation agent from the viewpoint of keeping the cleaning solution weakly alkaline, and examples thereof include triethanolamine and dimethylaminoethanol. These cationic agents can be used alone or in admixture of two or more.

The addition amount of the cationic agent is not particularly limited as long as the resin having an acidic functional group can be neutralized and water-solubilized, but is preferably added so that the value represented by Formula 1 is 0.8 or more. . By adding a sufficient amount of cationic agent so that the value represented by Formula 1 is 0.8 or more, it is possible to reduce the possibility of resin precipitation and to easily redisperse the coagulated pigment. It becomes. The value represented by Formula 1 is preferably 1.2 or more, more preferably 1.5 or more, still more preferably 1.8 or more, and most preferably 2.0 or more. On the other hand, if an excessive amount of a cationic agent is added, the pH of the cleaning liquid becomes high, and there is a possibility of damaging members of the ink jet apparatus. Therefore, the value represented by Formula 1 is preferably 10 or less. More preferably, it is 8.0 or less, More preferably, it is 5.0 or less, Most preferably, it is 3.0 or less.
[Formula 1]
Amount of basic functional group of cationic agent in cleaning solution [mmol] / Amount of acidic functional group of resin in cleaning solution [mmol]

The amount of acidic functional groups and the amount of basic functional groups in Formula 1 are calculated by the following method.
Acidic functional group amount [mmol] = Resin acid value [mgKOH / g] /56.1 × Resin compounding amount per 100 g of ink [g]
Amount of basic functional group [mmol] = Basic functional group value of cationic agent × Amount of cationic agent per 100 g of ink [g] / Formula amount of cationic agent [g / mol] × 10 ^ 3

  In this invention, it is preferable that content of water-soluble resin is 0.01 to 10 weight% with respect to the whole washing | cleaning liquid. More preferably, it is 0.1 to 7.5% by weight, and most preferably 1 to 5% by weight. When the amount is less than 0.01% by weight, the redispersibility of the dried and fixed pigment is deteriorated, and the detergency may not be maintained. On the other hand, when the content is more than 10% by weight, a dry aggregate of the resin may be generated, and the detergency may not be maintained.

  The organic solvent used in the present invention is used for the purpose of suppressing drying due to water evaporation of the cleaning liquid and preventing dry precipitation of the water-soluble resin in the cleaning liquid. For this reason, even if the water in the cleaning liquid dries, the water-soluble resin remains in a dissolved state, and the cleaning liquid itself is prevented from being dried and fixed.

  Therefore, it is desirable that the boiling point of the organic solvent used in the present invention is high. In particular, an organic solvent having a temperature lower than 200 ° C. may gradually evaporate at room temperature. Therefore, it is not particularly limited to the kind of solvent, but it is desirable to contain at least one kind of organic solvent having a boiling point of 200 ° C. or higher.

  Any organic solvent that is compatible with water can be used as the organic solvent used in the present invention, but it is preferable to contain at least one organic solvent having a boiling point of 200 ° C. or higher. Organic solvents having a boiling point of 200 ° C or higher include glycerin, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, (# 200), polyethylene glycol (# 400), polyethylene glycol (# 600), triethylene glycol monomethyl ether, diethylene glycol Monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, 1,3-propanediol, dipropylene glycol, polypropylene glycol and the like can be used. Preferred are glycerin, polyethylene glycol (# 200), polyethylene glycol (# 400) and 1,3-propanediol, more preferred are glycerin and 1,3-propanediol, and most preferred is glycerin. Further, it may be used by mixing with an organic solvent having a boiling point of less than 200 ° C. As the organic solvent having a boiling point of less than 200 ° C., propylene glycol, ethylene glycol, 1,2-butanediol and the like can be used.

  The content of the organic solvent is preferably 2 to 50% by weight with respect to the total amount of the cleaning liquid. When the amount is less than 2% by weight, the above effect may not be expected. On the other hand, when the amount is more than 50% by weight, the viscosity of the cleaning liquid rises, and after cleaning, the cleaning liquid may remain in the vicinity of the nozzle, resulting in ejection failure. More preferably, it is the range of 5-45 weight%, More preferably, it is the range of 10-40 weight%. In particular, the content of the organic solvent having a boiling point of 200 ° C. or higher is preferably 2 to 50% by weight. More preferably, it is the range of 5 to 40 weight%, More preferably, it is the range of 10 to 30 weight%.

  As the water used in the present invention, ion-exchanged water (deionized water) is preferably used instead of general water containing various ions.

  Although there is no restriction | limiting in particular as content of the water which can be used by this invention, 40 to 90 weight% is preferable with respect to the washing | cleaning liquid whole quantity.

  Furthermore, in addition to the above-mentioned components, the cleaning liquid of the present invention contains preservatives, antifungal agents, antifoaming agents, surface conditioners, pH adjusters as long as they do not impair the cleaning properties and mixing stability with the ink. An agent or the like can be appropriately added. Examples of these addition amounts are in the range of 0.05 to 10% by weight with respect to the total amount of the cleaning liquid.

  The cleaning liquid of the present invention preferably has a pH of 7.0 or more and 10.0 or less. This means that when the pH is less than 7.0, the acid value of the contained water-soluble resin is not sufficiently neutralized, and resin precipitation may occur in the cleaning liquid. The pH is preferably 7.0 or more. Moreover, when pH is higher than 10.0, there exists a high possibility that the various members used for an inkjet printer will be damaged. Also, the pigment ink used in the ink jet printer may not be able to maintain the dispersion stability of the pigment, and the pH is preferably 10.0 or less. About these pH, it adjusts with the kind and quantity of the cationic agent which neutralize the water-soluble resin used in a washing | cleaning liquid.

Ink composition The ink for inkjet in the present invention contains at least a pigment, water, and an organic solvent. Hereinafter, the ink composition will be described.

  As the ink-jet ink of the present invention, any of inorganic pigments and organic pigments can be used. Examples of inorganic pigments include titanium oxide, zinc white, zinc sulfide, lead white, calcium carbonate, precipitated barium sulfate, white carbon, alumina white, kaolin clay, talc, bentonite, black iron oxide, cadmium red, brown rice, molybdenum red, Molybdate orange, chrome vermilion, yellow lead, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, viridian, titanium cobalt green, cobalt green, cobalt chrome green, Victoria green, ultramarine, bituminous, cobalt blue, cerulean blue, Examples thereof include cobalt silica blue, cobalt zinc silica blue, manganese violet, and cobalt violet.

  Examples of organic pigments include azo pigments, phthalocyanine pigments, anthraquinone pigments, quinacridone pigments, isoindolinone pigments, quinophthalone pigments, dye lake pigments, and fluorescent pigments.

  More specifically, examples of cyan pigments include C. I. Pigment Blue 1, 2, 3, 15: 1, 15: 3, 15: 4, 15: 6, 16, 21, 22, 60, 64 and the like. CI Pigment Red 5, 7, 9, 12, 31, 48, 49, 52, 53, 57, 97, 112, 120, 122, 146, 147, 149, 150, 168, 170, 177, 178 as magenta pigments , 179, 184, 188, 202, 206, 207, 209, 238, 242, 254, 255, 264, 269, 282, CI Pigment Violet 19, 23, 29, 30, 32, 36, 37, 38, 40, 50 etc. are mentioned. CI Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 20, 24, 74, 83, 86, 93, 94, 95, 109, 110, 117, 120, 125, 128 , 129, 137, 138, 139, 147, 148, 150, 151, 154, 155, 166, 168, 180, 185, 213 and the like.

  Examples of the black pigment include carbon black produced by the furnace method and the channel method. For example, these carbon blacks have a primary particle size of 11 to 40 nm, a specific surface area by BET method of 50 to 400 m2 / g, a volatile content of 0.5 to 10%, a pH value of 2 to 10, etc. Is preferred. The following are mentioned as a commercial item which has such a characteristic. For example, No.33, 40, 45, 52, 900, 2200B, 2300, MA7, MA8, MCF88 (Mitsubishi Chemical), RAVEN1255 (Colombian Carbon), REGA330R, 400R, 660R, MOGUL L, ELFTEX415 ( As described above, manufactured by Cabot), Nipex90, Nipex150T, Nipex160IQ, Nipex170IQ, Nipex75, Printex85, Printex95, Printex90, Printex35, PrintexU (above, manufactured by Evonik Degussa) and the like can be preferably used.

  CI Pigment Green 7, 10, 36, CI Pigment Brown 3, 5, 25, 26, CI Pigment Orange 2, 5, 7, 13, 14, 15, 16, 24 other than cyan, magenta, yellow, and black , 34, 36, 38, 40, 43, 62, 63, 64, 71 and the like.

  These pigments may be used alone or in combination of two or more. The pigment content is 0.1 to 20%, preferably 1 to 10%, more preferably 2 to 7%, based on the total mass of the ink.

  When these pigments are used, it is preferable to use them dispersed in an ink medium in order to maintain long-term ink stability. As a method for dispersing the pigment, there are a method in which the surface of the pigment is modified by oxidation treatment or the like and the pigment is dispersed without a dispersant (self-dispersion), and a method in which the pigment is dispersed using a surfactant or resin as a dispersant. In the present invention, it is preferable that at least one acidic functional group is directly bonded to the pigment surface or contained in a dispersant such as a surfactant or a resin, and the pigment is stably dispersed. If it is, it will not be limited to any method.

  Examples of the pigment dispersion resin include an acrylic resin, a styrene acrylic resin, a maleic acid resin, a styrene maleic resin, an α-olefin maleic resin, a urethane resin, and an ester resin. Among these, it is preferable to use an acrylic resin or a styrene acrylic resin. In addition, the use of the water-soluble resin contained in the cleaning liquid of the present invention as the pigment-dispersed resin is more preferable because the detergency can be improved.

A conventionally known organic solvent can be used as the organic solvent contained in the ink of the present invention.
As the organic solvent that can be used in the present invention, glycol ethers and diols are preferable, and (poly) alkylene glycol monoalkyl ether and alkanediol having 3 to 6 carbon atoms are particularly preferable.
Specific examples of glycol ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monopentyl ether, diethylene glycol monohexyl ether, triethylene Glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene Glycol monobutyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, and the like.
Specific examples of diols include 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, Examples include 1,2-hexanediol, 1,6-hexanediol, and 2-methyl-2,4-pentanediol.
Among these, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, 1,2-propanediol, 1,3-propanediol, and 1,2-butanediol are preferable.
These solvents may be used alone or in combination.
Furthermore, depending on the type of substrate to be printed, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methyl-2-oxazolidinone, 3-ethyl for the purpose of improving its solubility Adding nitrogen-containing compounds such as 2-oxazolidinone, N, N-dimethyl-β-methoxydipropionamide, N, N-dimethyl-β-ethoxypropionamide, N, N-dimethyl-β-butoxypropionamide You can also.

  The content of the water-soluble organic solvent that can be used in the present invention is preferably 10% by weight to 60% by weight and more preferably 20% by weight to 50% by weight of the total amount of the ink.

  Moreover, in order to improve the tolerance of printed matter, a binder resin can be further added to the inkjet ink of the present invention. As binder resins for water-based inks, water-soluble resins and resin fine particles are known. The cleaning liquid of the present invention is particularly excellent in the detergency of ink using a water-soluble resin, so that it is preferably used in combination with an ink using a water-soluble resin.

  Examples of the binder resin include acrylic resin, urethane resin, styrene butadiene resin, vinyl chloride resin, and polyolefin resin. Considering the stability of ink and the durability of printed matter, it is preferable to use an acrylic resin.

  The content of the binder resin in the ink is in the range of 1% to 20%, preferably in the range of 2% to 15%, more preferably 3%, based on the total mass of the ink in solid content. The range is from% to 10%.

  In addition to the above-mentioned components, the ink of the present invention may be added with a surface conditioner, an antifoaming agent, a thickener, a pH adjuster, a preservative, etc., in order to obtain an ink having desired physical properties as required. An agent can be added as appropriate. The additive amount of these additives is 0.01% by weight or more and 10% by weight or less, preferably 0.05% by weight or more and 5% by weight or less, more preferably 0.1% by weight or more and 3% by weight or less based on the total weight of the ink. .

Hereinafter, the present invention will be described more specifically with reference to examples.

(1) Preparation of inkjet cleaning liquid The raw materials shown in Table 1 were mixed at the ratio shown in the table, and stirred using a disper until the resin was completely dissolved. Then, it filtered using a 1 micrometer membrane filter and obtained the washing | cleaning liquid for inkjet of an Example and a comparative example. The pH of the obtained washing solution was measured with a pH meter (H51, D51-AC).

(2) Preparation of ink-jet ink After pre-dispersing the ink mixed in the ratio shown in Table 1 with a disper, the ink and zirconia beads are charged into a mayonnaise bottle, and this dispersion is performed with a paint shaker It was. After dispersion, the zirconia beads and the ink were separated by filtration through a 10 μm membrane filter, and then filtered through a 1 μm membrane filter to obtain inkjet inks 1 to 3 for evaluation.

The following items were evaluated for the inkjet cleaning liquids obtained in the above Examples and Comparative Examples. The evaluation results are shown in Table 3.

(Evaluation 1: Head member compatibility evaluation)
The cleaning liquid was sealed in an ink jet head and allowed to stand at 60 ° C. for a certain period, and then the head member was confirmed for breakage. The evaluation criteria are as follows.
◎: No damage to the head member was confirmed after 6 months ○: No damage to the head member was confirmed even after 3 months ×: Damage to the head member was confirmed after 3 months

(Evaluation 2: Resin deposition of cleaning liquid)
Collect 5g of the cleaning solution in a Mentum can and dry it in a 60 ° C oven for a certain period of time. After drying, it was visually evaluated whether or not the resin was deposited. The evaluation criteria are as follows.
A: The resin was in a dissolved state even after 3 hours. O: The resin was in a dissolved state even after 1 hour. X: Precipitation of the resin was confirmed.

(Evaluation 3: Redispersibility of pigment ink)
Weigh 1 g of the evaluation ink into a mentum can, dry it in an oven at 60 ° C. for 1 hour, add 3 g of the cleaning liquid to the dried and fixed ink, and stir the mixture uniformly. did. The evaluation was performed for each of inks 1 to 3. The evaluation criteria are as follows.
◎: The ink that was dry fixed after 1 hour was completely dissolved ○: The ink that was dry fixed after 24 hours was completely dissolved ×: The ink that was dry fixed after 24 hours was not completely dissolved

Claims (6)

An inkjet cleaning liquid containing at least water, an organic solvent, a resin having an acidic functional group, and a cationic agent,
An inkjet cleaning liquid , wherein the resin having an acidic functional group has an aromatic ring in a resin skeleton and is neutralized with a cationic agent. 2. The inkjet cleaning liquid according to claim 1, wherein the value represented by Formula 1 is 0.8 or more.
[Formula 1]
Amount of basic functional group of cationic agent in cleaning solution [mmol] / Amount of acidic functional group of resin in cleaning solution [mmol]   The inkjet cleaning liquid according to claim 1, wherein the organic solvent contains at least one water-soluble organic solvent having a boiling point of 200 ° C. or higher.   The inkjet cleaning liquid according to claim 1, wherein the inkjet cleaning liquid has a pH of 7.0 or more and 10.0 or less.   An ink jet cleaning liquid and an ink set comprising the ink jet cleaning liquid according to claim 1 and an ink jet ink containing a pigment as a colorant. The ink contains a pigment-dispersed resin,
6. The inkjet cleaning liquid and ink set according to claim 5, wherein the pigment-dispersed resin contains the same resin as the resin having an acidic functional group in the inkjet cleaning liquid.