JP2008222947A - Ink for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink for inkjet recording, which is excellent in storage stability and discharging stability and has a high chromogenic property on plain paper and glossy paper and a high glossing property on glossy paper. <P>SOLUTION: This ink for inkjet recording is characterized by comprising water, surface-treated carbon black which can be dispersed in an aqueous solvent without a dispersant and has an average particle diameter of ≤50 nm, a compound of formula (1) and a resin emulsion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink for ink jet recording which is excellent in storage stability and ejection stability and has both high color developability on plain paper and glossy paper and high gloss on glossy paper.

  Many conventional inks for ink jet recording use dyes as coloring materials, and those using pigments are beginning to spread. Ink using the pigment was dispersed using a method using a surfactant as a means for dispersing the pigment in water (see Patent Document 1) or a dispersion polymer having a hydrophobic part and a hydrophilic part. (See Patent Document 2) Further, a method of coating the surface of a pigment with a polymer has been studied, and as an example, a method using a phase inversion emulsification reaction or an acid precipitation method has been studied (see Patent Document 3).

JP-A-01-301760 Japanese Patent Publication No. 5-064724 Japanese Patent Laid-Open No. 10-140065

  However, in any case, since a polymer containing styrene as a main constituent is used as a method for dispersing the pigment, the fixability is not so much, and yellowing is easily caused by long-term storage of the printed matter. Further, in the normal case, when a substance having a hydrophilic part and a hydrophobic part such as a surfactant or glycol ether is present, there is a problem that adsorption / desorption tends to occur and storage stability is inferior. Conventional water-based inks require a substance having a hydrophilic part and a hydrophobic part such as a surfactant and glycol ether in order to reduce bleeding on paper. Ink that does not use these substances has insufficient permeability to paper, and there is a problem that the type of paper is limited in order to perform uniform printing, which tends to cause deterioration of the printed image.

  Further, for example, additives for improving the print quality (acetylene glycol, acetylene alcohol, silicon surfactant, di (tri) ethylene glycol monobutyl ether or 1,2-alkylene glycol or a mixture thereof) to the conventional dispersion Long-term storage stability cannot be obtained, and in the case of pigment inks, the re-solubility is poor, so that the ink dries and easily becomes clogged with the nozzles of the ink-jet head, and the adhesion used for the substances constituting the head However, the adhesive strength is reduced due to deterioration of the agent and the like, resulting in poor discharge stability.

  In addition, the pigment dispersed by such a general dispersing agent has a residual dispersant remaining in the ink system, and the dispersing agent does not contribute sufficiently to the dispersion and becomes detached from the pigment and has a high viscosity. There was a problem of ending up. When the viscosity is increased, the amount of the coloring material such as pigment is limited, and there is a problem that sufficient print quality cannot be obtained particularly on plain paper.

  The ink for inkjet recording of the present invention contains water, at least a surface-treated carbon black dispersible in an aqueous solvent without a dispersant, a compound of formula (1), and a resin emulsion, and has an average particle size of 50 nm or less. It is characterized by.

  The ink for ink jet recording of the present invention is excellent in storage stability and ejection stability, and has the effect of providing an ink for ink jet recording having both high color developability on plain paper and glossy paper and high gloss on glossy paper.

  The ink for ink jet recording of the present invention is excellent in storage stability, has high color development on plain paper and glossy paper, has sufficient glossiness on glossy paper and has fixability, and stable ink discharge from the ink jet head. This is due to the result of intensive studies in view of the demand for characteristics such as excellent properties.

  The ink for inkjet recording of the present invention comprises water, a surface-treated carbon black having an average particle diameter of 50 nm or less that can be dispersed in an aqueous solvent without a dispersant, a compound of formula (1), and a resin emulsion. It is characterized by that.

  Here, the “surface-treated carbon black dispersible in an aqueous solvent without a dispersant” is obtained by directly or indirectly binding a large number of hydrophilic groups to the surface with a hydrophilic group-imparting agent. Examples of the hydrophilic group bonded to the surface of the surface-treated carbon black include a sulfone group, a carboxyl group, a carbonyl group, a hydroxyl group, a phosphate group, a quaternary ammonium, and salts thereof. Hydrophilic group-imparting agents are those that impart a sulfone group, such as sulfuric acid, fuming sulfuric acid, sulfur trioxide, chlorosulfuric acid, fluorosulfuric acid, amidosulfuric acid, sulfonated pyridine salt, sulfamic acid, etc. As, hypohalite such as sodium hypochlorite and potassium hypochlorite can be used. In addition to the chemical treatment described above, there is a method of imparting a carboxylic acid group by physical oxidation such as vacuum plasma treatment.

  Further, when the average particle diameter of the surface-treated carbon black that can be dispersed in an aqueous solvent without a dispersant as an ink jet ink exceeds 50 nm, glossiness on glossy paper is lowered. If the adduct of alkyl alcohol polyoxypropylene and polyoxyethylene has less than 8 carbon atoms, the glossiness of glossy paper decreases. If it exceeds 18, the viscosity of the ink increases and ejection stability cannot be obtained.

  In the present invention, the compound of the formula (1) preferably has R as an alkanol group having 8 to 18 carbon atoms. When the number of carbon atoms is less than 8, glossiness on glossy paper is difficult to obtain. If it exceeds 18, an increased amount of ethyleneoxy is required to improve the solubility in water. However, if this is done, foaming is likely to occur, ink-jet dots are likely to be lost, and color development on plain paper. The nature is also reduced. n is preferably 4 to 12, and if it is less than 4, glossiness on glossy paper is difficult to improve, and if it exceeds 12, a large amount of addition of ethyleneoxy is required to improve solubility in water. Foaming is likely to occur, and ink-jet dot loss is likely to occur, and color development on plain paper is also reduced. m is from 1 to 12, but if it is less than 1, the solubility in water decreases, so the amount added is limited and glossiness of glossy paper cannot be obtained. If it exceeds 12, foaming is likely to occur, and ink-jet dot loss is likely to occur, and in addition, the color developability on plain paper also decreases. The addition of propyleneoxy and ethyleneoxy to the alkyl group may be random or block, but the structure in which propyleneoxy is added to the alkyl group as a block and then ethyleneoxy is added as a block is random addition or alkylation. Glossiness on glossy paper is improved and color developability on plain paper is improved compared to adding ethyleneoxy in blocks and then adding ethyleneoxy in blocks.

  Examples of the carbon black used in the present invention include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, and channel black. These are subjected to surface treatment for imparting the above-mentioned hydrophilic groups, and used as surface-treated carbon black. Commercially available surface-treated carbon black can also be used. In the present invention, the amount of carbon black added as a pigment is preferably 0.5% to 30%, more preferably 1.0% to 12%. If the addition amount is less than this, the print density cannot be ensured, and if the addition amount is more than this, the viscosity of the ink increases or structural viscosity is generated in the viscosity characteristics, and the ejection stability of the ink from the ink jet head tends to deteriorate. .

  The resin emulsion used in the present invention is preferably in the form of an aqueous emulsion in which resin fine particles are dispersed in an aqueous solvent. Furthermore, the resin fine particles have a hydrophilic group on the surface, are inactive with respect to other components used in the ink for ink jet recording of the present invention, have a glass transition temperature of 60 ° C. or less and an average particle size of 50 nm or less. Some are preferred. When the glass transition point of the resin fine particles exceeds 60 ° C. or the average particle diameter exceeds 50 nm, the gloss on glossy paper decreases. The addition amount as resin fine particles is preferably 0.5% to 30%. If the addition amount is less than this, the fixing property and rubbing resistance cannot be secured, and if the addition amount is more than this, the glossiness is lowered and the ink ejection stability tends to deteriorate. By using such a resin emulsion composed of resin fine particles in the ink composition, fixability, abrasion resistance, glossiness and color developability when printed by the ink jet method are improved.

  The resin fine particles can be produced by an emulsion polymerization method in water in which an unsaturated vinyl monomer is added with a polymerization initiator and an emulsifier. As unsaturated vinyl monomers, (meth) acrylic acid ester monomers, aromatic vinyl monomers, vinyl ester monomers, vinyl cyanide monomers commonly used in emulsion polymerization , Halogenated monomers, olefin monomers, and diene monomers, specifically, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (Meth) acrylate, isobutyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) ) Acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, (Meth) acrylic esters such as rohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, and glycidyl (meth) acrylate; vinyl esters such as vinyl acetate; vinyl such as acrylonitrile and methacrylonitrile Cyanogen compounds; halogenated monomers such as vinylidene chloride and vinyl chloride; aromatic vinyl monomers such as styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylanisole, and vinylnaphthalene Olefins such as ethylene, propylene, and isopropylene; dienes such as butadiene and chloroprene; and vinyl monomers such as vinyl ether, vinyl ketone, and vinyl pyrrolidone. Further, resin fine particles obtained by polymerizing a combination of a plurality of the monomers may be used, and furthermore, a plurality of resin fine particles prepared by polymerizing a single monomer may be used.

  A polymerization initiator, an emulsifier, a surfactant, a molecular weight adjusting agent, a neutralizing agent, and the like used for emulsion polymerization of resin fine particles can be used according to a known method. Especially when a polymerizable surfactant is used as an emulsifier, since the polymerizable surfactant is copolymerized with the monomer, the emulsifier remaining and released in the liquid can be reduced, so that the ejection stability of the inkjet ink can be improved. it can.

  2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl-5 One or more selected from alkylene oxide adduct of decyne-4,7-diol and alkylene oxide adduct of 3,6-dimethyl-4-octyne-3,6-diol is plain paper at less than 0.05% by weight This is not preferable because of increased bleeding. On the other hand, if it exceeds 1% by weight, the storage stability as an ink-jet ink deteriorates and long-term storage becomes difficult. More preferably, it is 0.1 wt% or more and 0.7 wt%.

  2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 2,4,7,9-tetramethyl-5 The alkylene oxide adduct of decyne-4,7-diol is commercially available, Surfinol 104, Surfinol 82, Surfinol 2502, Surfinol 420, Surfinol 440, Surfinol 465, Surfinol 485, manufactured by Nissin Chemical. It can be obtained as acetylenol EOO, acetylenol E40, acetylenol E100, etc. manufactured by Kawaken Fine Chemicals.

  In the present invention, it preferably comprises 1,2-alkylene glycol. Among the 1,2-alkylene glycols, 1,2-hexanediol and 4-methyl-1,2-pentanediol are particularly preferable. By using the pigment according to the present invention and further using these, the ejection stability of the inkjet ink can be improved. Improves bleeding when printing on plain paper.

  Further, it comprises at least one selected from di (tri) ethylene glycol monobutyl ether, (di) propylene glycol monobutyl ether, di (tri) ethylene glycol monopentyl ether and di (tri) ethylene glycol monohexyl ether. Is preferred. By using the pigment according to the present invention and further using these glycol ethers, the bleeding when printed on plain paper by the ink jet method is further reduced, and the printing quality is improved.

  Moreover, it is also preferable that 2-butyl-2-ethyl-1,3-propanediol is included, and the pigment according to the present invention is used, and 2-butyl-2-ethyl-1,3-propanediol is further used. This improves glossiness on glossy paper and improves color development on plain paper.

  Moreover, although the polymer in this invention has a carboxyl group, it is preferable to comprise triethanolamine and / or tripropanolamine as the counter ion. By using triethanolamine and / or tripropanolamine, clogging of the inkjet ink is less likely to occur even in a dry state.

  Further, similarly, in order to make it difficult to cause clogging of the ink jet, it is preferable to include one or more selected from glycerin, trimethylolethane, trimethylolpropane, tetrasaccharide, pentasaccharide and hexasaccharide.

(Example)
The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples, and various modifications can be made without departing from the gist of the present invention.

  Commercially available carbon black (# 900: Mitsubishi Chemical Co., Ltd., primary particle size 16 nm) 100.0 parts by weight is mixed with 900.0 parts by weight of water, and bead filling ratio 70% with Eiger Motor Mill M250 (Eiger Japan). And dispersed for 2 hours under the condition of a rotational speed of 5000 rpm. To this dispersion, 1500.0 parts by weight of sodium hypochlorite (effective chlorine concentration: 12%) was added dropwise and reacted for 5 hours while stirring with an Eiger motor mill, then the temperature was controlled at 100 ° C. and stirred for 8 hours. . Subsequently, the obtained slurry was filtered, washed with water, and adjusted to a carbon black pigment concentration of 15% to obtain a surface-treated carbon black dispersion “B1”.

  10. Anionic polymerizable surfactant Aqualon KH-10 (Daiichi Kogyo Seiyaku Co., Ltd.) previously dissolved in 600.0 parts by weight of water, 40.0 parts by weight of benzyl methacrylate and 80.0 parts by weight of water in advance. 0 parts by weight was added and stirred. This was adjusted to pH 8 with a 1 mol / l potassium hydroxide aqueous solution, and then charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a temperature controller, and a nitrogen introduction tube. After the internal temperature of the reaction vessel was raised to 80 ° C., an aqueous potassium persulfate solution in which 1.0 part by weight of potassium persulfate was dissolved as a polymerization initiator was added dropwise to 100.0 parts by weight of water, while introducing nitrogen. Polymerization was carried out at 6 ° C for 6 hours. After completion of the polymerization, the pH was adjusted to 8 with a 1 mol / l potassium hydroxide aqueous solution. Subsequently, this was subjected to ultrafiltration by a cross flow method using an ultrafiltration device, and the solid content concentration was adjusted to 20% to obtain a resin emulsion “E1”.

  Next, inkjet inks having the ink composition 1 shown in Table 2 were prepared. In the compound of the formula (1), R is a nonanol group, n is 6, m is 5, and block addition in the order of PO-EO is used.

  The surface-treated carbon black dispersion “B1” and the resin emulsion “E1” were produced in the same manner as in Example 1. Next, ink jet inks having the ink composition 2 shown in Table 2 were produced. In the compound of the formula (1), R is a dodecanol group, n is 7, m is 6, and block addition in the order of PO-EO was used.

The surface-treated carbon black dispersion “B1” and the resin emulsion “E1” were produced in the same manner as in Example 1.
Anionic polymerizable surfactant Aqualon KH-10 (Daiichi Kogyo Seiyaku Co., Ltd.) previously dissolved in 600.0 parts by weight of water, 40.0 parts by weight of 2-ethylhexyl methacrylate and 80.0 parts by weight of water in advance. 10.0 parts by weight was added and stirred. This was adjusted to pH 8 with a 1 mol / l potassium hydroxide aqueous solution, and then charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a temperature controller, and a nitrogen introduction tube. After the internal temperature of the reaction vessel was raised to 80 ° C., an aqueous potassium persulfate solution in which 1.0 part by weight of potassium persulfate was dissolved as a polymerization initiator was added dropwise to 100.0 parts by weight of water, while introducing nitrogen. Polymerization was carried out at 6 ° C. for 6 hours. After completion of the polymerization, the pH was adjusted to 8 with a 1 mol / l potassium hydroxide aqueous solution. Subsequently, this was subjected to ultrafiltration by a cross flow method using an ultrafiltration device, and the solid content concentration was adjusted to 20% to obtain a resin emulsion “E2”.

  Next, inkjet inks having the ink composition 3 shown in Table 2 were prepared. In the compound of the formula (1), R is a nonanol group, n is 6, m is 5, and block addition in the order of PO-EO is used.

  The surface-treated carbon black dispersion “B1” was produced in the same manner as in Example 1, and the resin emulsion “E2” was produced in the same manner as in Example 3.

  Next, inkjet inks having the ink composition 4 shown in Table 2 were prepared. In the compound of the formula (1), R is a nonanol group, n is 6, m is 5, and block addition in the order of PO-EO is used.

(Comparative Example 1)
The surface-treated carbon black dispersion “B1” was produced in the same manner as in Example 1.

  Anionic polymerizable surfactant Aqualon KH-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) previously dissolved in 600.0 parts by weight of water, 40.0 parts by weight of isobornyl methacrylate and 80.0 parts by weight of water in advance. 10.0 parts by weight was added and stirred. This was adjusted to pH 8 with a 1 mol / l potassium hydroxide aqueous solution, and then charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a temperature controller, and a nitrogen introduction tube. After the internal temperature of the reaction vessel was raised to 80 ° C., an aqueous potassium persulfate solution in which 1.0 part by weight of potassium persulfate was dissolved as a polymerization initiator was added dropwise to 100.0 parts by weight of water, while introducing nitrogen. Polymerization was carried out at 6 ° C for 6 hours. After completion of the polymerization, the pH was adjusted to 8 with a 1 mol / l potassium hydroxide aqueous solution. Subsequently, this was subjected to ultrafiltration by a cross flow method using an ultrafiltration device, and the solid content concentration was adjusted to 20% to obtain a resin emulsion “E3”. Next, an inkjet ink having an ink composition 5 shown in Table 2 was prepared. In the compound of the formula (1), R is a nonanol group, n is 6, m is 5, and block addition in the order of PO-EO is used.

(Comparative Example 2)
Commercially available carbon black (# 5: Mitsubishi Chemical Co., Ltd., primary particle size 76 nm) 100.0 parts by weight is mixed with 900.0 parts by weight of water, and bead filling ratio 70% with Eiger Motor Mill M250 (Eiger Japan). And dispersed for 2 hours under the condition of a rotational speed of 5000 rpm. To this dispersion, 1500.0 parts by weight of sodium hypochlorite (effective chlorine concentration: 12%) was added dropwise and reacted for 5 hours while stirring with an Eiger motor mill, then the temperature was controlled at 100 ° C. and stirred for 8 hours. . Subsequently, the obtained slurry was filtered, washed with water, and adjusted to a carbon black pigment concentration of 15% to obtain a surface-treated carbon black dispersion “B2”.

  The resin emulsion “E1” was produced in the same manner as in Example 1.

  Next, inkjet inks having the ink composition 6 shown in Table 2 were prepared. In the compound of the formula (1), R is a nonanol group, n is 6, m is 5, and block addition in the order of PO-EO is used.

(Comparative Example 3)
The surface-treated carbon black dispersion “B2” was produced in the same manner as in Comparative Example 2, and the resin emulsion “E2” was produced in the same manner as in Example 3.

  Next, inkjet inks having the ink composition 7 shown in Table 2 were prepared. In the compound of the formula (1), R is a nonanol group, n is 6, m is 5, and block addition in the order of PO-EO is used.

(Comparative Example 4)
The surface-treated carbon black dispersion “B2” was produced in the same manner as in Comparative Example 2, the resin emulsion “E2” was produced in the same manner as in Example 3, and the resin emulsion “E3” was produced in the same manner as in Comparative Example 1. .

  Next, inkjet inks having the ink composition 8 shown in Table 2 were prepared. In the compound of the formula (1), R is a nonanol group, n is 6, m is 5, and block addition in the order of PO-EO is used.

(Comparative Example 5)
The surface-treated carbon black dispersion “B2” was produced in the same manner as in Comparative Example 2, and the resin emulsion “E3” was produced in the same manner as in Comparative Example 1.

  Next, inkjet inks having the ink composition 9 shown in Table 2 were prepared. In the compound of the formula (1), R is a nonanol group, n is 6, m is 5, and block addition in the order of PO-EO is used.

(Evaluation Test 1: Evaluation Method for Colorability of Plain Paper)
The inkjet ink according to Examples 1 to 4 and Comparative Examples 1 to 5 was solid-printed on XeroxP paper (manufactured by Fuji Xerox Co., Ltd.) using an inkjet printer (EM-930C, manufactured by Seiko Epson Corporation) to obtain a test specimen. It was. The print mode was paper: plain paper, print quality: super fine, color correction: none, print direction: bidirectional. And the OD value of each color was measured using GRETAGMACBETH SPECTROSCANSP50 (made by Gretag (USA)). The results are shown in Table 1 as OD values.

(Evaluation Test 2: Glossiness Evaluation Method)
The inkjet inks according to Examples 1 to 4 and Comparative Examples 1 to 5 were solid-printed on PM photographic paper (Seiko Epson) with an inkjet printer (EM-930C, manufactured by Seiko Epson) to obtain a test specimen. The print mode was paper: photo print paper, print quality: photo, color correction: none, print direction: bidirectional. The 20 degree gloss of this test specimen was measured with a gloss meter (HG-268, manufactured by Suga Test Instruments Co., Ltd.). The results are shown in Table 1.

(Evaluation Test 3: Dispersibility Evaluation Method)
The average particle diameter of the particles in the inkjet inks according to Examples 1 to 4 and Comparative Examples 1 to 5 was measured with a laser particle size analyzer (Zeta Sizer 3000, manufactured by Malvern (UK)). The results are shown in Table 1.

(Evaluation Test 4: Evaluation Method of Storage Stability)
The initial viscosity of the pigment dispersion for inkjet ink used in Examples 1 to 4 and Comparative Examples 1 to 5 and the viscosity after standing at 70 ° C. for 1 week were measured using a rolling ball viscometer (AMVn, Anton Paar (Germany) )). The results are shown in Table 1 as storage stability: viscosity (mPa · s) / initial viscosity (mPa · s) after standing at 70 ° C. for 1 week.

(Evaluation Test 5: Fixing Evaluation Method)
The inkjet inks according to Examples 1 to 4 and Comparative Examples 1 to 5 were solid-printed in a 10 mm × 10 mm area on PM photographic paper (Seiko Epson) with an inkjet printer (EM-930C, manufactured by Seiko Epson). The print mode was paper: photo print paper, print quality: photo, color correction: none, print direction: bidirectional. Thereafter, it was left at a temperature of 25 ° C. for 6 hours. Scotch mending tape (manufactured by Sumitomo 3M) 18 mm width type is affixed lightly so as to completely cover the printing area of the obtained specimen, and a cylindrical metal roller having a diameter of 20 mm and a weight of 200 g is placed thereon. On top of this, this was rolled and the tape application part was reciprocated four times. Next, the attached tape was peeled off, and the degree of peeling was visually observed and evaluated according to the following criteria. The results are shown in Table 1.

  A: No peeling occurs.

  B: The area where peeling occurred is less than 10% with respect to the total area of the printing region.

  C: The area where peeling occurred was 10% or more with respect to the total area of the printing region.

In addition, the symbol shown in Table 2 is as follows.
TEGmBE: triethylene glycol monobutyl ether BEPD: 2-butyl-2-ethyl-1,3-propanediol 1,2-HD: 1, 2-hexanediol TMP: trimethylolpropane

  In Table 2, the compounding ratio of each component is shown in% by weight. Formula (1) R represents the number of carbon atoms of the alkyl group, n represents the number of added moles of propyleneoxy PO, and m represents the number of moles of added ethyleneoxy EO. The formula (1) is added in the order of addition of propyleneoxy PO to the alkyl group R as R-POEO, and that in which ethyleneoxy EO is added to the alkyl group R as R-EOPO. ) The addition form indicates whether propyleneoxy PO and ethyleneoxy EO are added to the alkyl group R in a block manner or randomly.

  As can be seen from the results of Table 1, when the inkjet inks according to Examples 1 to 4 were used, any of the evaluation tests 1 to 5 were good results, but the inkjet inks according to Comparative Examples 1 to 5 were used. In such a case, any of the evaluation tests 1 to 4 or a plurality of items do not give a good result.

Claims (5)

Ink for ink jet recording comprising water, surface-treated carbon black having an average particle diameter of 50 nm or less that can be dispersed in an aqueous solvent without a dispersant, a compound of formula (1), and a resin emulsion .

  0.05% to 1% by weight of 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 2,4,7,9-tetramethyl-5-decyne-4,7 The ink for inkjet recording according to claim 1, comprising at least one selected from alkylene oxide adducts of diols.   The ink for inkjet recording according to claim 1, comprising 1,2-alkylene glycol.   The ink for inkjet recording according to any one of claims 1 to 3, comprising at least one selected from di (tri) ethylene glycol monobutyl ether and (di) propylene glycol monobutyl ether.   The inkjet recording ink according to claim 1, comprising 2-butyl-2-ethyl-1,3-propanediol.