JP6565046B2 - Water-based ink - Google Patents

Description

  The present invention relates to an aqueous ink containing polyester resin particles, a method for producing the same, and an ink jet recording method.

  In the field of commercial printing used for product packaging and advertisement, etc., printing has conventionally been performed on resin-based recording media such as polyethylene terephthalate, polyvinyl chloride, polyethylene, polypropylene, and nylon with solvent-based inks and UV curable inks. Has been done. On the other hand, from the viewpoints of reducing environmental burden, energy saving, safety, etc., as a printing method using water-based ink, it is required to utilize an inkjet recording method or a flexographic printing method. In particular, the ink jet recording method is a recording method in which ink droplets are directly ejected and adhered to a recording medium from very fine nozzles to obtain characters and images. The spread is remarkable due to the many advantages of non-contact with printed matter. Thus, an attempt has been made to utilize an ink jet recording method for the resin recording medium.

In Patent Document 1, the water-insoluble or poorly water-soluble color is used as a water-based ink that has good bleeding, scratch resistance, and the like of a printed matter, and in particular, improved scoring at the head when used in a heat jet type ink jet printer. A polyester emulsion adsorbed with a material obtained by copolycondensation of a specific diol component, trimellitic anhydride, and a polyvalent carboxylic acid other than trimellitic anhydride and / or a derivative thereof. A water-based ink is described.
Patent Document 2 discloses an ink jet recording ink containing resin fine particles, wherein the resin fine particles are non-spherical particles having a weight-converted average particle diameter in the range of 0.05 to 2.0 μm. It describes that both stability against sedimentation and reliability against nozzle clogging can be achieved, and extremely high recording quality can be realized.

JP 2000-7963 A JP-A-8-259863

However, resin-based recording media such as polyethylene terephthalate (hereinafter also referred to as “PET”) and polyvinyl chloride (hereinafter also referred to as “PVC”) are non-water-absorbing or low-water-absorbing media. Moreover, since the ink spread on the film is poor, the formed ink film has poor smoothness, and the adhesion is insufficient.
In addition, PVC films frequently used in sign graphics such as vehicle wrapping are required to have alcohol resistance against lower alcohols having 4 or less carbon atoms such as ethanol, which can be adapted for outdoor use and cleaning. Conventional inks including those disclosed in Documents 1 and 2 have not reached the technical level that satisfies all of these characteristics.
Therefore, the present invention provides a water-based ink excellent in adhesion and alcohol resistance to a resin recording medium having a polarity such as PVC, a method for producing the same, and an ink jet recording method.

  The inventors of the present invention are that the polyester contained in the polyester resin particles is a polyester obtained by polycondensation of an alcohol component containing a divalent or trivalent alicyclic alcohol and a carboxylic acid component. I found that the problem could be solved.

That is, the present invention relates to [1] to [3].
[1] A water-based ink containing a colorant and polyester resin particles,
The polyester contained in the polyester resin particles is a polyester (A) obtained by polycondensation of an alcohol component containing a divalent or trivalent alicyclic alcohol and a carboxylic acid component, and the polyester (A) An aqueous ink having an acid value of 5 mgKOH / g or more and 50 mgKOH / g or less.
[2] A method for producing a water-based ink having the following steps (1) and (2).
Step (1): Polyester having an acid value of 5 mgKOH / g or more and 50 mgKOH / g or less obtained by polycondensation of an alcohol component containing a divalent or trivalent alicyclic alcohol and a carboxylic acid component is mixed with an aqueous medium. And emulsifying to obtain an aqueous dispersion of polyester resin particles Step (2): Mixing the aqueous dispersion of polyester resin particles obtained in Step (1) with an aqueous dispersion containing a colorant, Step of obtaining aqueous ink [3] After the aqueous ink described in [1] is attached to a resin recording medium by an ink jet recording method, the resin recording medium to which the aqueous ink is attached is set to 40 ° C. or higher and 150 ° C. or lower. An inkjet recording method for heating.

  ADVANTAGE OF THE INVENTION According to this invention, the water-based ink which has the outstanding adhesiveness and alcohol resistance with respect to resin-made recording media, its manufacturing method, and the inkjet recording method can be provided.

[Water-based ink]
The water-based ink of the present invention contains a colorant and polyester resin particles. The water-based ink is a polyester (A) obtained by polycondensing an alcohol component containing a divalent or trivalent alicyclic alcohol and a carboxylic acid component, in which the polyester contained in the polyester resin particles is, The acid value of the polyester is 5 mgKOH / g or more and 50 mgKOH / g or less.
The reason why the water-based ink having such a configuration has excellent adhesion and alcohol resistance to a resin recording medium is not clear, but is considered as follows.
The water-based ink of the present invention contains a colorant and polyester resin particles. When the ink adheres to the recording medium during printing, the polyester contained in the polyester resin particles diffuses on the printing surface of the resin recording medium and acts as a fixing aid for the colorant. Here, the polyester is obtained by polycondensation of an alcohol component containing a divalent or trivalent alicyclic alcohol and a carboxylic acid component. By using a divalent or trivalent alicyclic alcohol as a raw material monomer for polyester, an ester group having a high polarity in the molecular chain is present with an appropriate inter-ester group length via a alicyclic portion having a low polarity. It is considered that the adhesiveness is improved because it strongly interacts with the polar group of the resin recording medium having a high polarity such as. Further, on the printing surface, a polyester resin that protects the printing surface because a highly polar ester group is oriented toward the recording medium made of a highly polar resin such as PVC and a low polarity alicyclic portion is oriented on the air side. It is considered that the penetration and swelling of alcohol in the membrane are suppressed and the alcohol resistance is improved.
In this specification, “water-based ink” may be simply referred to as “ink”.

[Polyester resin particles]
The polyester resin particles in the present invention include a polyester (A) obtained by polycondensation of an alcohol component containing a divalent or trivalent alicyclic alcohol and a carboxylic acid component.

[Polyester (A)]
Polyester (A) is composed of an alcohol component containing a divalent or trivalent alicyclic alcohol as an alcohol component, and a carboxylic acid from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance. Polyester obtained by polycondensation with components is used.

(Alicyclic alcohol)
The alicyclic alcohol is preferably divalent. The number of carbon atoms of the alicyclic alcohol is preferably 5 or more, more preferably 6 or more, and still more preferably 10 or more from the viewpoint of improving alcohol resistance, and adhesion to a resin recording medium having polarity. From the viewpoint of improving the ratio, it is preferably 30 or less, more preferably 25 or less, and still more preferably 20 or less.
The number of aliphatic hydrocarbon ring sites contained in the alicyclic alcohol is preferably 2 or more, and preferably 3 or less, more preferably 2.

一般式（Ｉ）において、環Ｃｙ¹及び環Ｃｙ²は、それぞれ独立に、環構造の環員数３以上１２以下の脂肪族炭化水素環であり、Ｒ⁵及びＲ⁶は、それぞれ独立に、炭素数１以上８以下の炭化水素基であり、ｄ及びｅはそれぞれ独立に０以上３以下の整数（好ましくは０）であり、Ｒ¹及びＲ²はそれぞれ独立に水素原子、又は炭素数１以上３以下のアルキル基であり、ｎは０又は１（好ましくは１）であり、Ｒ³及びＲ⁴はそれぞれ独立に炭素数１以上３以下（好ましくは１）のアルカンジイル基であり、ａ及びｂはそれぞれ独立に０又は１（好ましくは０）である。
環Ｃｙ¹及び環Ｃｙ²において、環構造の環員数は、極性を有する樹脂製記録媒体への密着性及び耐アルコール性を向上させる観点から、それぞれ独立に、好ましくは３以上、より好ましくは４以上、更に好ましくは５以上であり、そして、好ましくは１２以下、より好ましくは１０以下、更に好ましくは８以下であり、環構造の環員数は６がより更に好ましい。 The alicyclic alcohol is preferably a compound represented by the following general formula (I).

In general formula (I), ring Cy ¹ and ring Cy ² are each independently an aliphatic hydrocarbon ring having 3 to 12 ring members in the ring structure, and R ⁵ and R ⁶ are each independently carbon A hydrocarbon group having a number of 1 or more and 8 or less, d and e are each independently an integer of 0 or more and 3 or less (preferably 0), and R ¹ and R ² are each independently a hydrogen atom or a carbon number of 1 or more An alkyl group having 3 or less, n is 0 or 1 (preferably 1), R ³ and R ⁴ are each independently an alkanediyl group having 1 to 3 carbon atoms (preferably 1), and a and Each b is independently 0 or 1 (preferably 0).
In the ring Cy ¹ and the ring Cy ² , the number of ring members in the ring structure is preferably independently 3 or more, more preferably 4 from the viewpoint of improving the adhesion to the resin recording medium having polarity and the alcohol resistance. More preferably, it is 5 or more, and preferably 12 or less, more preferably 10 or less, still more preferably 8 or less, and the number of ring members of the ring structure is more preferably 6.

Examples of the divalent or trivalent alicyclic alcohol include 1,4-cyclohexanediol (in formula (I), ring Cy ¹ ; 6-membered ring, n = a = b = d = e = 0), 1, 3-cyclohexanedimethanol (in general formula (I), ring Cy ¹ ; 6-membered ring, n = 0, a = b = 1, R ³ = R ⁴ = CH ₂ , d = e = 0), tricyclode Candimethanol, 1,4-cyclohexanedimethanol (in formula (I), ring Cy ¹ ; 6-membered ring, n = 0, a = b = 1, R ³ = R ⁴ = CH ₂ , d = e = 0 ), Hydrogenated bisphenol A [2,2-bis (4-hydroxycyclohexyl) propane] (in general formula (I), ring Cy ¹ , ring Cy ² ; 6-membered ring, n = 1, a = b = d = ^{e = 0, R 1 = R} 2 = CH 3), hydrogenated bisphenol F (bis (4-hydroxy-cyclo f In Sil) methane) (formula (I), ring Cy ^1, ring Cy ^2; 6-membered ring, n = 1, a = b = d = e = 0, R 1 = R 2 = H), spiro glycol, Examples include dihydroxymethyl tricyclodecane. Among these, it is preferably at least one selected from 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and hydrogenated bisphenol A.
An alicyclic alcohol can be used individually by 1 type or in combination of 2 or more types.

  The content of the alicyclic alcohol is preferably 5 mol% or more, more preferably 10 mol% or more, more preferably in the alcohol component, from the viewpoint of improving the adhesion to the resin recording medium having polarity and the alcohol resistance. Preferably, it is 20 mol% or more, and from the same viewpoint, preferably 100 mol% or less, more preferably 80 mol% or less, and more preferably 80 mol% or less, from the viewpoint of improving the adhesion to a resin recording medium having polarity. Is 70 mol% or less.

(Other alcohol)
As the alcohol component, a diol other than those described above, a trihydric or higher polyhydric alcohol, and the like may be contained.
Examples of the diol include aliphatic diols and aromatic diols having 2 to 12 carbon atoms in the main chain.
Examples of the aliphatic diol having 2 to 12 carbon atoms in the main chain include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8- Examples include octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol.
Examples of the aromatic diol include an alkylene oxide adduct of bisphenol A.
The alkylene oxide adduct of bisphenol A is preferably a compound represented by the following general formula (II) from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance.

In the general formula (II), OR ¹¹ and R ¹² O are all alkyleneoxy groups, preferably each independently an alkyleneoxy group having 1 to 4 carbon atoms, more preferably an ethyleneoxy group or propylene. An oxy group, more preferably a propyleneoxy group.
x and y correspond to the number of added moles of alkylene oxide. Furthermore, from the viewpoint of reactivity with the carboxylic acid component, the average value of the sum of x and y is preferably 2 or more, and is preferably 7 or less, more preferably 5 or less, and even more preferably 3 or less. .
Further, x OR ¹¹ and y R ¹² O may be the same or different from each other, but they are the same from the viewpoint of improving adhesion to a resin recording medium having polarity. Is preferred. The alkylene oxide adduct of bisphenol A may be used alone or in combination of two or more. The alkylene oxide adduct of bisphenol A is preferably a propylene oxide adduct of bisphenol A or an ethylene oxide adduct of bisphenol A, and more preferably a propylene oxide adduct of bisphenol A.

The alcohol component other than the alicyclic alcohol is preferably an alkylene oxide having 2 or 3 carbon atoms of bisphenol A (average added mole number) from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance. 1 to 16)), more preferably a propylene oxide adduct of bisphenol A or an ethylene oxide adduct of bisphenol A, more preferably a propylene oxide adduct of bisphenol A.
In addition, the said alcohol component can be used individually by 1 type or in combination of 2 or more types.

  The content of the alkylene oxide adduct of bisphenol A in the alcohol component, which is a raw material monomer for polyester, is preferably 0 mol% or more from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance. More preferably, it is 20 mol% or more, More preferably, it is 30 mol% or more, Preferably it is 95 mol% or less, More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.

(Carboxylic acid component)
Examples of the carboxylic acid component include dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, acid anhydrides thereof, and alkyl esters having 1 to 3 carbon atoms thereof. Among them, dicarboxylic acids are preferably included. More preferably, it consists of dicarboxylic acid.
Dicarboxylic acids include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids.
Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, and the like, and terephthalic acid is preferred from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance.
Examples of the aliphatic dicarboxylic acid include fumaric acid, adipic acid, sebacic acid, maleic acid, azelaic acid, succinic acid, an alkyl group having 1 to 20 carbon atoms, or a succinic acid substituted with an alkenyl group having 2 to 20 carbon atoms. Etc. Specific examples of the succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms include dodecyl succinic acid, dodecenyl succinic acid, octenyl succinic acid, and the like. Among these, from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance, preferably, it is at least one selected from fumaric acid, adipic acid, sebacic acid, and dodecenyl succinic acid, and more Fumaric acid or adipic acid is preferred, and fumaric acid is more preferred.
Examples of the alicyclic dicarboxylic acid include cyclohexane dicarboxylic acid. Examples of the trivalent or higher polyvalent carboxylic acid include trimellitic acid, 2,5,7-naphthalene tricarboxylic acid, and pyromellitic acid.

  The carboxylic acid component is preferably selected from isophthalic acid, terephthalic acid, fumaric acid, adipic acid, sebacic acid, and dodecenyl succinic acid from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance. More preferably, it is at least one selected from terephthalic acid and fumaric acid.

  The said carboxylic acid component can be used individually by 1 type or in combination of 2 or more types.

  The equivalent ratio (COOH group / OH group) of the carboxyl group (COOH group) of the carboxylic acid component to the hydroxy group (OH group) of the alcohol component in the polyester (A) is determined by the adhesion to the resin recording medium having polarity and From the viewpoint of improving the alcohol resistance, it is preferably 0.65 or more, more preferably 0.8 or more, and preferably 1.2 or less, more preferably 1.1 or less.

The polyester (A) preferably has a carboxylic acid group at the molecular chain terminal from the viewpoint of improving the dispersion stability of the resin particles in the aqueous medium.
Polyester (A) may be used alone or in combination of two or more.

(Physical properties of polyester (A))
The softening point of the polyester (A) is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, further preferably 110 ° C. or higher, from the viewpoint of improving the storage stability of the resin particles and the ink, and the same viewpoint. Therefore, it is preferably 165 ° C. or lower, more preferably 150 ° C. or lower, and further preferably 140 ° C. or lower.

The glass transition temperature of the polyester (A) is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and still more preferably 70 ° C. or higher, from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance. And preferably 110 ° C. or lower, more preferably 100 ° C. or lower, and still more preferably 95 ° C. or lower.
In addition, when using 2 or more types of polyester (A) mixed, the softening point and glass transition temperature are the values obtained by the method of an Example description as a mixture of 2 or more types of polyester, respectively.

  The acid value of the polyester (A) is 5 mg KOH / g from the viewpoint of improving the adhesion to a resin recording medium having polarity and the alcohol resistance, and improving the dispersion stability of the resin particles in the aqueous medium. Or more, preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more, more preferably 20 mgKOH / g or more, and from the same viewpoint, 50 mgKOH / g or less, preferably 40 mgKOH / g or less, More preferably, it is 35 mgKOH / g or less, More preferably, it is 30 mgKOH / g or less, More preferably, it is 25 mgKOH / g or less.

  The softening point, glass transition temperature, and acid value of the polyester (A) are all obtained by appropriately adjusting the type of monomer used in the production of the polyester, the blending ratio, the polycondensation temperature, and the reaction time. be able to.

(Method for producing polyester (A))
The polyester (A) can be produced by subjecting a carboxylic acid component and an alcohol component to a polycondensation reaction. For example, it is produced by polycondensing the alcohol component and the carboxylic acid component at a temperature of 120 ° C. or higher and 250 ° C. or lower using an esterification catalyst and a polymerization inhibitor as necessary in an inert gas atmosphere. be able to.
As the esterification catalyst, an esterification catalyst such as a tin compound such as dibutyltin oxide or di (2-ethylhexanoic acid) tin or a titanium compound such as titanium diisopropylate bistriethanolamate can be used.
The amount of esterification catalyst used is not limited, but is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, with respect to 100 parts by mass of the total amount of the carboxylic acid component and the alcohol component, and The amount is preferably 1.5 parts by mass or less, more preferably 1.0 part by mass or less.
Moreover, a polymerization inhibitor can be used as needed. Examples of the polymerization inhibitor include 4-tert-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.005 part by mass or more, and preferably 0 with respect to 100 parts by mass of the total amount of the carboxylic acid component and the alcohol component. 0.5 parts by mass or less, more preferably 0.1 parts by mass or less.

  In the present invention, the polyester (A) includes not only unmodified polyesters but also polyesters modified to such an extent that the properties are not substantially impaired. Examples of the modified polyester include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like. And a composite resin having two or more kinds of resin units including a polyester unit.

The polyester resin particle is a resin other than the polyester (A), for example, a polyester resin other than the polyester (A), a styrene-acrylic copolymer, an epoxy resin, a polycarbonate, a polyurethane, or the like as long as the effects of the present invention are not impaired. It may contain.
In addition, the polyester resin particles may contain additives such as reinforcing fillers such as fibrous substances, antioxidants, anti-aging agents, and the like as optional components, as long as the effects of the present invention are not impaired.

  In the polyester resin particles, the content of the polyester (A) is preferably 60% by mass or more, more preferably 80% by mass or more, from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance. More preferably, it is 90 mass% or more, More preferably, it is 98 mass% or more, More preferably, it is 100 mass%.

[Colorant]
In the present invention, the colorant means a pigment or a dye. The colorant may be used in the form of fine particles that are stable in the ink using a surfactant or a dispersing polymer.
Examples of the colorant used in the present invention include pigments, hydrophobic dyes, water-soluble dyes (acidic dyes, reactive dyes, direct dyes, etc.). Among these, from the viewpoint of improving the dispersion stability of the ink, the water resistance of the printed matter, the glossiness, and the surface smoothness, at least one selected from a pigment and a hydrophobic dye is preferable, and a pigment is more preferable.

The pigment may be either an inorganic pigment or an organic pigment.
Examples of the inorganic pigment include carbon black and metal oxide. When used for black ink, carbon black is preferable.
Examples of organic pigments include azo pigments, diazo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthraquinone pigments, and quinophthalone pigments. A phthalocyanine pigment and a quinacridone pigment, more preferably copper phthalocyanine.
The hue is not particularly limited, and any chromatic pigment such as yellow, magenta, cyan, blue, red, orange, and green can be used.

  The organic pigment is preferably C.I. I. Pigment yellow, C.I. I. Pigment Red, C.I. I. Pigment orange, C.I. I. Pigment violet, C.I. I. Pigment blue, and C.I. I. One or more types of products selected from Pigment Green are listed.

In the present invention, a self-dispersing pigment can also be used. Self-dispersing pigments are those in which one or more hydrophilic functional groups (anionic hydrophilic groups such as carboxy groups and sulfonic acid groups, or cationic hydrophilic groups such as quaternary ammonium groups) are directly or other atomic groups. It means an inorganic pigment or an organic pigment that can be dispersed in an aqueous medium without using a surfactant or a resin. Here, as other atomic groups, an alkanediyl group having 1 to 12 carbon atoms, a phenylene group, a naphthylene group, or the like can be given.
The above-mentioned pigments can be used singly or in combination of two or more in any ratio.

  The hydrophobic dye means a dye having a solubility of preferably less than 6% by mass in 100 g of water (20 ° C.). Examples of the hydrophobic dye include oil-soluble dyes and disperse dyes.

  The colorants may be used alone or in combination of two or more in any proportion.

The content of the colorant is preferably 1% by mass or more, more preferably 2% by mass or more, and further preferably 3% by mass or more in the ink from the viewpoint of improving the dispersion stability and image density of the ink. Preferably, it is 25 mass% or less, More preferably, it is 10 mass% or less, More preferably, it is 5 mass% or less.
The mass ratio of the colorant to the polyester resin particles [colorant / polyester resin particles] is preferably in the ink, preferably 10/90 or more, from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance. More preferably, it is 20/80 or more, more preferably 30/70 or more, still more preferably 40/60 or more, and preferably 80/20 or less, more preferably 70/30 or less, still more preferably 60/40 or less. More preferably, it is 50/50 or less.

[Polymer particles containing colorant]
The colorant is preferably made into fine particles that are stable in the ink using a surfactant, a polymer, or the like. That is, the colorant is preferably used as a colorant dispersed with a polymer dispersant or a polymer particle containing a colorant, and improves the dispersion stability and image density of the ink, and the surface smoothness of the printed matter. From the viewpoint of improvement, it is more preferable to use as polymer particles containing a colorant.

  From the viewpoint of improving the image density of the ink, the volume average particle diameter of the polymer particles containing the colorant is preferably 40 nm or more, more preferably 50 nm or more, and preferably 200 nm or less, more preferably 150 nm or less. is there. The volume average particle diameter of the polymer particles containing the colorant is measured by a dynamic light scattering method, and specifically measured by the method of the example.

For the polymer particles containing the colorant, it is preferable to use a water-insoluble polymer from the viewpoint of improving the water dispersibility of the polymer particles in the ink and the image density of the ink. Here, the “water-insoluble polymer” refers to a polymer that is dried at 105 ° C. for 2 hours and reaches a constant weight, and when dissolved in 100 g of water at 25 ° C., the dissolved amount is 10 g or less. The dissolved amount is preferably 5 g or less, more preferably 1 g or less. In the case of an anionic polymer, the dissolution amount is the dissolution amount when the anionic group of the polymer is neutralized 100% with sodium hydroxide.
Examples of water-insoluble polymers include polyesters, polyurethanes, and vinyl polymers. From the viewpoint of improving the storage stability of ink, it is preferably obtained by addition polymerization of vinyl monomers (vinyl compounds, vinylidene compounds, vinylene compounds). Vinyl polymer.

  As the vinyl polymer, those having a constitutional unit derived from an ionic monomer and a constitutional unit derived from a hydrophobic monomer are preferable from the viewpoint of improving the storage stability and ejection property of the ink.

The ionic monomer is preferably an anionic monomer from the viewpoint of improving dispersion stability of the polymer particles containing the colorant in the ink. Examples of the anionic monomer include a carboxylic acid monomer, a sulfonic acid monomer, and a phosphoric acid monomer. Examples of the carboxylic acid monomer include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and 2-methacryloyloxymethyl succinic acid.
Among the anionic monomers, a carboxylic acid monomer is preferable and at least one selected from acrylic acid and methacrylic acid is more preferable from the viewpoint of improving dispersion stability of the polymer particles containing the colorant in the ink.
The amount of the ionic monomer component is preferably 2% by mass or more, more preferably 5% by mass or more in the water-insoluble polymer from the viewpoint of improving dispersion stability of the polymer particles containing the colorant in the ink. The content is preferably 8% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, and still more preferably 25% by mass or less.

Examples of the hydrophobic monomer include alkyl (meth) acrylates having an alkyl group having 1 to 22 carbon atoms, more preferably 6 to 18 carbon atoms; styrene monomers such as styrene, 2-methylstyrene, and divinylbenzene; benzyl ( Aromatic group-containing (meth) acrylates such as meth) acrylate and phenoxyethyl (meth) acrylate are exemplified, and styrene and benzyl (meth) acrylate are preferred. “(Meth) acrylate” indicates at least one selected from acrylate and methacrylate.
From the viewpoint of improving the dispersion stability of the polymer particles containing the colorant in the ink, benzyl (meth) acrylate is more preferable.
The amount of the hydrophobic monomer component is preferably 5% by mass or more, more preferably 10% by mass or more in the water-insoluble polymer from the viewpoint of improving the dispersion stability of the polymer particles containing the colorant in the ink. And, it is preferably 98% by mass or less, more preferably 80% by mass or less.

The vinyl polymer has a number average molecular weight of 500 or more and 100 having a polymerizable functional group such as a (meth) acryloyloxy group at one end from the viewpoint of improving dispersion stability of the polymer particles containing the colorant in the ink. , 000 or less macromer, and nonionic monomer having a polyoxyalkylene glycol chain.
The amount of the macromer and the nonionic monomer component is preferably 1% by mass or more, more preferably 5% by mass, respectively, in the water-insoluble polymer from the viewpoint of improving the dispersion stability of the polymer particles containing the colorant in the ink. %, And preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and further preferably 20% by mass or less.

  The monomer component of a vinyl polymer can be used individually by 1 type or in combination of 2 or more types, respectively.

  The weight average molecular weight of the water-insoluble polymer is preferably 5,000 or more, more preferably from the viewpoint of improving the dispersion stability of the polymer particles containing the colorant in the ink and the image density of the ink. It is 10,000 or more, more preferably 20,000 or more, and preferably 500,000 or less, more preferably 400,000 or less, still more preferably 300,000 or less, and further preferably 200,000 or less. In addition, the measurement of a weight average molecular weight can be performed by the method as described in an Example.

The water-insoluble polymer is produced by copolymerizing a monomer mixture by a known polymerization method. A preferred example of the polymerization method is a solution polymerization method in which the monomer mixture is heated and polymerized together with a polymerization initiator, a polymerization chain transfer agent, or the like in a solvent.
After completion of the polymerization reaction, the produced polymer may be isolated and purified from the reaction solution by a known method such as reprecipitation or solvent distillation.

(Production of polymer particles containing colorant)
The polymer particles containing a colorant include, for example, a water-insoluble polymer, an organic solvent, a colorant, water, and, if necessary, a mixture containing a neutralizer, a surfactant, and the like, and a colorant. After the dispersion of polymer particles to be obtained is obtained, the organic solvent can be removed from the dispersion to obtain an aqueous dispersion of polymer particles containing a colorant.

Although there is no restriction | limiting in the organic solvent in which a water-insoluble polymer is dissolved, C1-C3 aliphatic alcohol, C3-C5 ketones, ethers, esters, etc. are preferable, and ketones are more preferable, More preferred is methyl ethyl ketone. When a water-insoluble polymer is synthesized by a solution polymerization method, the solvent used in the polymerization may be used as it is.
When the water-insoluble polymer is an anionic polymer, an anionic group in the water-insoluble polymer may be neutralized using a neutralizing agent. When using a neutralizing agent, it is preferable to neutralize so that pH may be 7 or more and 11 or less. Examples of the neutralizing agent include bases such as lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia, and various amines. Further, the water-insoluble polymer may be neutralized in advance.

In the dispersion of polymer particles containing the colorant, the colorant is preferably 5% by mass or more, more preferably 10% from the viewpoint of improving dispersion stability of the polymer particles containing the colorant in the ink. % Or more, and preferably 50% by mass or less, more preferably 40% by mass or less.
The mass ratio of the amount of the colorant to the amount of the water-insoluble polymer [colorant / water-insoluble polymer] is preferably from the viewpoint of improving the dispersion stability of the polymer particles containing the colorant in the ink and in the aqueous medium. Is 50/50 or more, more preferably 60/40 or more, still more preferably 70/30 or more, and preferably 90/10 or less, more preferably 80/20 or less.

  There is no restriction | limiting in particular in the dispersion method of a dispersion. It is preferable to control the volume average particle diameter of the polymer particles containing the colorant to a desired particle diameter using a known kneader, disperser or the like. By removing the organic solvent from the obtained dispersion by a known method, an aqueous dispersion of polymer particles containing a colorant can be obtained.

  The obtained aqueous dispersion of polymer particles containing the colorant is preferably filtered through a wire mesh or the like to remove coarse particles and the like. In addition, from the viewpoint of improving the productivity and storage stability of the aqueous dispersion, the polymer particles containing the colorant are subjected to a crosslinking treatment, or optionally added to an aqueous ink described later, an organic solvent, an antiseptic, an anti-corrosion agent. Various additives such as glazes may be added to the aqueous dispersion of polymer particles containing a colorant.

  The solid content concentration of the aqueous dispersion of polymer particles containing a colorant improves the productivity and storage stability of the aqueous dispersion, as well as improves the adhesion to alcoholic recording media and the alcohol resistance. From the viewpoint of making it preferable, it is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less, and still more preferably 40% by mass. It is at most 35% by mass, more preferably at most 35% by mass.

[Optional components of water-based ink]
The water-based ink of the present invention includes an organic solvent, a penetrating agent, a dispersant, a surfactant, a viscosity modifier, an antifoaming agent, an antiseptic, an antifungal agent, a rust inhibitor, a pH adjuster, an antioxidant, and an ultraviolet absorber. Various additives such as an agent can be added.

[Organic solvent]
Examples of the organic solvent include polyhydric alcohol, polyhydric alcohol alkyl ether, polyhydric alcohol aryl ether, cyclic carbonate, nitrogen-containing heterocyclic compound, amide, amine, and sulfur-containing compound.

  Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3- Butanediol, 2,3-butanediol, 1,4-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 2 -Methyl-2,4-pentanediol, tetraethylene glycol, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3-butanetriol, 3-methyl-1,3 , 5-Pentanetriol, 2-D Le-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol.

  Examples of the polyhydric alcohol alkyl ether include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoisobutyl ether, tetraethylene glycol monomethyl ether. , Propylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, and the like.

Examples of the polyhydric alcohol aryl ether include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
Examples of the cyclic carbonate include ethylene carbonate and propylene carbonate.
Examples of the nitrogen-containing heterocyclic compound include N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, and ε-caprolactam.
Examples of the amide include formamide, N-methylformamide, N, N-dimethylformamide and the like.
Examples of the amine include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine and the like.
Examples of the sulfur-containing compound include dimethyl sulfoxide, sulfolane, thiodiethanol, thiodiglycol and the like.

The organic solvent may be used alone or in combination of two or more, but preferably used in combination of two or more.
Among these, at least one or more selected from polyhydric alcohols, polyhydric alcohol alkyl ethers, and nitrogen-containing heterocyclic compounds are preferable, and diethylene glycol, propylene glycol, dipropylene glycol, 1,2-butanediol, , 2-hexanediol, glycerin, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and 2-pyrrolidone are more preferable.
From the viewpoint of improving the dispersion stability of the ink, the content of the organic solvent is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 40% by mass or less, more preferably in the ink. Is 35% by mass or less.

[Surfactant]
Examples of the surfactant include nonionic surfactants, anionic surfactants, amphoteric surfactants, silicone surfactants, and fluorine surfactants.

Examples of the nonionic surfactant include glycol ethers such as acetylene glycol and polyoxyethylene alkyl ether; polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, and the like.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecyl benzene sulfonate, oxalate sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.

Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, lauryl dimethylamine oxide, myristyl dimethylamine oxide, stearyl dimethylamine oxide, dihydroxyethyl lauryl amine oxide, and the like. Is mentioned.
Examples of the silicone surfactant include polyester-modified silicone and polyether-modified silicone.
Examples of the fluorine-based surfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic compound, a perfluoroalkyl phosphate compound, and a perfluoroalkyl ethylene oxide adduct.

One surfactant may be used alone, or two or more surfactants may be used in combination.
Among these, at least one selected from nonionic surfactants and silicone surfactants is preferable, at least one selected from glycol ethers, polyester-modified silicones, and polyether-modified silicones is more preferable, and glycol ethers are further included. Preferably, at least one selected from acetylene glycol and polyoxyethylene alkyl ether is more preferable.

  The content of the surfactant is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and preferably 5% by mass in the ink from the viewpoint of improving the dispersion stability of the ink. % Or less, more preferably 2% by mass or less.

There is no restriction | limiting in particular as an antifoamer, According to the objective, it can select suitably, For example, a silicone type antifoamer, a polyether type antifoamer, a fatty-acid-ester type antifoamer, etc. are mentioned.
Examples of the antiseptic and antifungal agent include 1,2-benzisothiazolin-3-one, sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, sodium pentachlorophenol, etc. Is mentioned.
Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and the like.
The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 or more without adversely affecting the ink to be prepared, and any substance can be used according to the purpose. For example, diethanolamine, Amines such as triethanolamine; hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide, potassium hydroxide; carbonates of alkali metals such as lithium carbonate, sodium carbonate, potassium carbonate; ammonium hydroxide, quaternary An ammonium hydroxide etc. are mentioned.
Examples of the antioxidant include phenolic antioxidants (including hindered phenolic antioxidants), amine antioxidants, sulfurous antioxidants, phosphorus antioxidants, and the like.
Examples of the UV absorber include benzophenone UV absorbers, benzotriazole UV absorbers, salicylate UV absorbers, and the like.

[Manufacture of water-based ink]
The water-based ink of the present invention can be preferably produced by performing the following steps (1) and (2).
Step (1): Polyester (A) having an acid value of 5 mgKOH / g or more and 50 mgKOH / g or less, obtained by polycondensation of an alcohol component containing a divalent or trivalent alicyclic alcohol and a carboxylic acid component. Step of mixing and emulsifying with an aqueous medium to obtain an aqueous dispersion of polyester resin particles Step (2): An aqueous dispersion of polyester resin particles obtained in step (1) and an aqueous dispersion containing a colorant To obtain water-based ink

[Step (1)]
In the step (1), the polyester (A) is mixed with an aqueous medium and emulsified to obtain an aqueous dispersion of polyester resin particles.

As the aqueous medium in the step (1), those containing water as a main component are preferable. From the viewpoint of improving the dispersion stability of the polyester resin particle dispersion and reducing the environmental load, the content of water in the aqueous medium is , Preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably substantially 100% by mass, still more preferably 100% by mass. As water, deionized water, ion exchange water, and distilled water are preferably used.
As components other than water, an organic solvent that dissolves in water such as an alkyl alcohol having 1 to 5 carbon atoms; a dialkyl ketone having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone; and a cyclic ether such as tetrahydrofuran is used.

<Phase inversion emulsification method>
In the step (1), a step (phase inversion emulsification method) in which a resin containing the polyester (A) is dissolved in an organic solvent, an aqueous medium is gradually added, phase is changed, and emulsification is performed.
In the phase inversion emulsification method, it is preferable to neutralize a solution obtained by dissolving polyester (A) in an organic solvent by adding a basic compound.

  Examples of the organic solvent in the phase inversion emulsification method include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and diethyl ketone; ether solvents such as dibutyl ether, tetrahydrofuran, and dioxane; acetate esters such as ethyl acetate and isopropyl acetate. Solvent: Alkyl halide solvents such as dichloromethane and chloroform. Among these, from the viewpoint of easy removal from the mixed solution after addition of the aqueous medium, it is preferably at least one selected from ketone solvents and acetate solvents, and more preferably methyl ethyl ketone, ethyl acetate and acetic acid. At least one selected from isopropyl, more preferably methyl ethyl ketone.

  The mass ratio of the organic solvent to the resin in the polyester resin particles (organic solvent / resin) is preferably from the viewpoint of dissolving the resin and facilitating phase inversion to an aqueous medium, and improving the dispersion stability of the resin particles. 0.3 or more, more preferably 0.5 or more, further preferably 0.7 or more, and preferably 5.0 or less, more preferably 3.0 or less, still more preferably 2.0 or less, still more preferably Is 1.5 or less.

Examples of the basic compound in the step (1) include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, ammonia, trimethylamine, ethylamine, diethylamine, triethylamine, diethanolamine, triethanolamine, and tributylamine. And nitrogen-containing basic substances. Among these, sodium hydroxide or ammonia is preferable from the viewpoint of improving the dispersion stability of the polyester resin particles.
The degree of neutralization (mol%) of the polyester with the basic compound is preferably 10 mol% or more, more preferably 50 mol% or more, and still more preferably 60 mol%, from the viewpoint of improving the dispersion stability of the polyester resin particles. And more preferably 150 mol% or less, more preferably 100 mol% or less, still more preferably 80 mol% or less.
In addition, the neutralization degree (mol%) of polyester can be calculated | required by following Formula.
Degree of neutralization = {[addition mass of neutralizer (g) / equivalent of neutralizer] / [[acid value of polyester (mgKOH / g) × mass of polyester (g)] / (56 × 1000)]} × 100

  In addition, you may mix the said arbitrary components, such as surfactant and a coloring agent, with an organic solvent further.

As the aqueous medium for the phase inversion emulsification method, those similar to the examples of the aqueous medium are preferable.
In the phase inversion emulsification method, the aqueous medium is added at least until the phase inversion to the aqueous medium is completed.

The temperature at which the aqueous medium is mixed is preferably 10 ° C. or higher, more preferably 20 ° C. or higher, further preferably 25 ° C. or higher, and preferably 80 ° C. from the viewpoint of improving the dispersion stability of the polyester resin particles. C. or lower, more preferably 50 C or lower.
From the viewpoint of improving the dispersion stability of the polyester resin particles, the addition rate of the aqueous medium is preferably 0.5 parts by mass / min or more, more preferably 100 parts by mass with respect to 100 parts by mass of the resin until the phase inversion is completed. 1 part by weight or more, more preferably 3 parts by weight or more, and preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and further preferably 20 parts by weight or less. is there. There is no restriction | limiting in the addition rate of the aqueous medium after phase inversion.

  You may have the process of removing an organic solvent from the aqueous dispersion obtained by phase inversion emulsification as needed after phase inversion emulsification. The organic solvent may not be completely removed and may remain in the aqueous dispersion, and the residual amount of the organic solvent is preferably 1% by mass or less, more preferably 0.5% by mass or less in the aqueous dispersion. More preferably, it is substantially 0%.

The solid content concentration of the aqueous dispersion of polyester resin particles obtained in the step (1) is from the viewpoint of improving the productivity of the ink, and from the viewpoint of improving the adhesion to the resin recording medium having polarity and the alcohol resistance. , Preferably 10% by mass or more, more preferably 20% by mass or more, further preferably 25% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less. It is.
In addition, solid content is the total amount of non-volatile components, such as said arbitrary components, such as resin, surfactant and the coloring agent which can be added as needed.

The volume average particle diameter (D _V ) of the polyester resin particles in the aqueous dispersion is preferably 20 nm or more, more preferably 50 nm or more, from the viewpoint of improving adhesion to a resin recording medium having polarity and alcohol resistance. More preferably, it is 80 nm or more, and preferably 1000 nm or less, more preferably 500 nm or less, still more preferably 300 nm or less. The volume average particle diameter is measured by a dynamic light scattering method and is determined by the method described in the examples.

[Step (2)]
The aqueous dispersion containing the colorant in step (2) is preferably the above-mentioned aqueous dispersion.
In step (2), in addition to the colorant, at least one of the aforementioned optional components may be further mixed. For the mixing, for example, various stirring devices can be used.

The content of the polyester resin particles contained in the water-based ink is preferably 1 in the ink from the viewpoint of maintaining the viscosity of the ink properly and improving the adhesion to the resin recording medium having polarity and the alcohol resistance. % By mass or more, more preferably 2% by mass or more, further preferably 3% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, still more preferably. 7% by mass or less.
The content of the polyester (A) contained in the water-based ink is preferably in the ink from the viewpoint of maintaining the viscosity of the ink properly and improving the adhesion to the resin recording medium having polarity and the alcohol resistance. 0.6% by mass or more, more preferably 1.5% by mass or more, further preferably 2.5% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 10%. It is below mass%.
The water-based ink contains resin particles other than the polyester resin particles, for example, other polyester resin particles, acrylic resin particles, vinyl chloride resin particles, polyurethane resin particles, etc., as long as the effects of the present invention are not impaired. May be. The content of the resin particles other than the polyester resin particles is preferably 0.5% by mass or less, more preferably 0.2% by mass or less in the total resin particles in the water-based ink.

The content of the aqueous medium contained in the water-based ink is preferably 30% by mass or more, more preferably 40% by mass or more, and preferably 90% by mass or less in the ink from the viewpoint of keeping the viscosity of the ink properly. More preferably, it is 80 mass% or less, More preferably, it is 75 mass% or less.
The content of water contained in the water-based ink is preferably 30% by mass or more, more preferably 40% by mass or more, and preferably 90% by mass or less in the ink from the viewpoint of keeping the viscosity of the ink properly. More preferably, it is 80 mass% or less, More preferably, it is 75 mass% or less.

[Inkjet recording method]
The aqueous ink of the present invention can be used as an ink for ink jet recording. Since the water-based ink of the present invention is excellent in adhesion to a resin recording medium and alcohol resistance, it is suitably used as an inkjet recording ink for commercial or industrial printing.
As a preferred embodiment when the aqueous ink of the present invention is used in an ink jet recording method, the aqueous recording ink of the present invention is attached to a resin recording medium by an ink jet recording method, and then the resin recording medium to which the aqueous ink adheres is used. Heat to 40 ° C or higher and 100 ° C or lower.
The water-based ink of the present invention can be used for both office printing and commercial and industrial printing of catalogs, flyers, packages, labels and the like. Suitable for commercial and industrial label printing, such as PET, PVC, polyethylene (hereinafter also referred to as “PE”), polypropylene (hereinafter also referred to as “PP”), nylon (hereinafter also referred to as “NY”), etc. Since it can be suitably used for a low water-absorbent resin recording medium, it is suitable for commercial and industrial printing.
In the present invention, “non-water-absorbing or low water-absorbing” means that the water absorption amount of the recording medium is 0 g / m ² or more and 10 g / m ² or less at a contact time of 100 msec between the recording medium and water. Means.

Examples of the resin recording medium include polyethylene terephthalate, polyvinyl chloride (hereinafter also referred to as “PVC”), polyethylene, polypropylene, nylon, and the like.
Among these, it can be suitably used in a method for forming an image by attaching the water-based ink of the present invention to a polyvinyl chloride recording medium.
The recording medium is preferably a resin film. Examples of the film include a polyester film, a polyvinyl chloride film, a polypropylene film, a polyethylene film, and a nylon film. Among these, a polyvinyl chloride film is preferable.
These films may be subjected to surface treatment such as corona treatment as necessary.
Commercially available films include, for example, Lumirror T60 (manufactured by Toray Industries, Inc., polyethylene terephthalate, thickness 125 μm, water absorption 2.3 g / m ² ), PVC80BP (manufactured by Lintec Corporation, polyvinyl chloride, water absorption 1.4 g / M ² ), KAINUS KEE70CA (manufactured by Lintec Corporation, polyethylene), YUPO SG90 PAT1 (manufactured by Lintec Corporation, polypropylene), Bonile RX (manufactured by Kojin Film & Chemicals Co., Ltd., nylon) and the like.

In the ink jet recording method of the present invention, a known ink jet recording apparatus can be used. Examples of the ink jet recording apparatus include a thermal ink jet recording apparatus and a piezo ink jet recording apparatus. The water-based ink of the present invention is more preferably used as a piezoelectric ink-jet recording ink.
In the present invention, it is preferable that after the water-based ink is attached to the resin recording medium, the resin recording medium to which the water-based ink is attached is heated to 40 ° C. or more and 100 ° C. or less. The resin contained in the polyester resin particles in the water-based ink diffuses on the printing surface of the resin recording medium on the film, and can act as a colorant fixing aid when forming a coating film. The adhesion to the recording medium and the alcohol resistance can be further improved.
The heating temperature of the resin recording medium is preferably 50 ° C. or more, more preferably 60 ° C. or more, and preferably from the viewpoint of improving the adhesion to the resin recording medium having polarity and the alcohol resistance. 90 ° C or lower, more preferably 85 ° C or lower.

  Hereinafter, the present invention will be described more specifically with reference to examples and the like. In the following examples and the like, each physical property was measured by the following method.

[Acid value of polyester]
It measured according to JIS K0070. However, the measurement solvent was a mixed solvent of acetone and toluene [acetone: toluene = 1: 1 (volume ratio)].

[Softening point of polyester]
Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), a 1 g sample was heated at a heating rate of 6 ° C./min, and a load of 1.96 MPa was applied by a plunger, and the diameter was 1 mm and the length was 1 mm. Extruded from the nozzle. The amount of plunger drop of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point.

[Glass transition temperature of polyester]
Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of a sample is weighed in an aluminum pan, heated to 200 ° C., and the temperature is lowered from that temperature. The sample for measurement was prepared by cooling to 0 ° C. at a rate of 10 ° C./min. Then, it heated up with the temperature increase rate of 10 degrees C / min, and measured the calorie | heat amount. Among the observed endothermic peaks, the peak temperature with the maximum peak area is taken as the maximum peak temperature of the endotherm, the extension of the baseline below the maximum peak temperature of the endotherm, and the maximum slope from the peak of the peak to the peak apex The temperature at the point of intersection with the tangent line indicating the glass transition temperature.

[Volume Average Particle Diameter (D _v ) of Polyester Resin Particles, Polymer Particles Containing Colorant (Pigment-Containing Anionic Polymer Particles)]
(1) Measuring device: Zeta potential / particle size measuring system “ELSZ-2” (manufactured by Otsuka Electronics Co., Ltd.)
(2) Measurement conditions: cumulant analysis method. A dispersion liquid diluted with water so that the concentration of the particles to be measured is about 5 × 10 ⁻³ mass% is put in a measurement cell, the temperature is 25 ° C., the angle between incident light and the detector is 90 °, and the number of integration is 100 times. Then, the refractive index of water (1.333) was input as the refractive index of the dispersion solvent and measured.

[Solid content concentration of aqueous dispersion of polyester resin particles]
Using an infrared moisture meter “FD-230” (manufactured by Kett Scientific Laboratory), 5 g of a measurement sample was dried at a temperature of 150 ° C. and in a measurement mode 96 (monitoring time 2.5 minutes / variation width 0.05%). The water dispersion (mass%) of the aqueous dispersion was measured. The solid content concentration was calculated according to the following formula.
Solid content concentration (% by mass) = 100-water content (% by mass)

[Weight average molecular weight of water-insoluble polymer (anionic polymer)]
Using the following measuring device and analytical column, gel permeation chromatography using a solution in which phosphoric acid and lithium bromide are dissolved in N, N-dimethylformamide at concentrations of 60 mmol / L and 50 mmol / L, respectively, as an eluent Measured by the method. The molecular weight (Mw, Mn) of the sample is several types of monodisperse polystyrene (product name: “TSKgel standard polystyrene”; type names: “A-500”, “A-2500”, “F-1”, “F-10”). “All of them were manufactured by Tosoh Corporation) as a standard sample and calculated based on a calibration curve prepared in advance. The sample was dissolved in N, N-dimethylformamide to give a solution having a solid content of 0.3% by mass.
<Measurement conditions>
Measuring device: “HLC-8120GPC” (manufactured by Tosoh Corporation)
Analytical column: "TSK-GEL α-M" x 2 (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Flow rate: 1 mL / min

[Solid content concentration of aqueous dispersion of polymer particles containing colorant (pigment-containing anionic polymer particles)]
In a 30 mL polypropylene container (inner diameter: 40 mm, height: 30 mm), weigh 10.0 g of sodium sulfate constant in a desiccator, add approximately 1.0 g of the sample to it, mix and then weigh accurately. The mixture was maintained at 105 ° C. for 2 hours to remove volatile matter, and further left in a desiccator for 15 minutes to measure the mass. The mass of the sample after removing the volatile matter was taken as the solid content and divided by the mass of the added sample to obtain the solid content concentration.

[Evaluation of adhesion]
An inkjet printer “IPSiO GX 2500” (Ricoh Co., Ltd., Piezo Method) was filled with water-based ink, and an A4 solid image was printed on a PVC film “Transparent PVC RE-137” (Mimaki Engineering Co., Ltd.). The sample was dried for 10 minutes with a dryer at 80 ° C., and allowed to stand for 1 day in an environment room at room temperature of 25 ° C. and relative humidity of 50% to prepare a sample. After that, a tape “Cello Tape CT15” (registered trademark) (made by Nichiban Co., Ltd.) having a length of 5 cm and a width of 15 mm is pasted on the printed surface of the sample by 4 cm, leaving a 1 cm margin, and an angle of 90 ° and a speed of 10 cm / sec. The tape was peeled off, and the remaining area of the coated surface of the sample was visually evaluated in the following five stages. The higher the score, the better the adhesion to PVC.
<Evaluation criteria>
No peeling or peeling but peeling area less than 5%: 5 points peeling area 5% or more and less than 25%: 4 points peeling area 25% or more but less than 50%: 3 points peeling area 50% or more but less than 75%: 2 points peeling 75% or more area: 1 point

[Evaluation of alcohol resistance]
An inkjet printer “IPSiO GX 2500” (Ricoh Co., Ltd., Piezo Method) was filled with water-based ink, and an A4 solid image was printed on a PVC film “Transparent PVC RE-137” (Mimaki Engineering Co., Ltd.). The sample was dried for 10 minutes with a dryer at 80 ° C., and allowed to stand for 1 day in an environment room at room temperature of 25 ° C. and relative humidity of 50% to prepare a sample. Thereafter, with a cotton swab impregnated with an aqueous solution of alcohol (ethanol, isopropanol) whose concentration was adjusted every 10% by mass in the range of 0 to 100% by mass, while applying as little load as possible to the coated surface of the sample, The coated surface was rubbed so as to stroke 10 times at a speed of 1 reciprocation per second with a width of 3 cm. The state of the coated surface was visually evaluated, and the highest alcohol concentration at which changes such as scratches, peeling, and cloudiness were not observed before and after rubbing was used as an index of alcohol resistance. The higher the concentration, the better the alcohol resistance.

[Production of polyester]
Production Example R1 (Production of Polyester A)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 4568 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 2,104-g of 2,2-bis (4-hydroxycyclohexyl) propane, 2542 g of terephthalic acid, and 40 g of di (2-ethylhexanoic acid) tin were added, heated to 230 ° C. with stirring in a nitrogen atmosphere, and maintained for 8 hours. After that, the pressure in the flask was further lowered and maintained at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 242 g of fumaric acid and 0.5 g of 4-tert-butylcatechol were added and held at 210 ° C. for 4 hours, and then the pressure in the flask was lowered to 8.3 kPa. For 4 hours to obtain polyester A. The characteristics of polyester A are shown in Table 1-1.

Production Example R2 (Production of Polyester B)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 5058 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Add 612 g of 2,2-bis (4-hydroxycyclohexyl) propane, 2540 g of terephthalic acid, and 40 g of di (2-ethylhexanoic acid) tin, heat to 230 ° C. with stirring in a nitrogen atmosphere, and hold for 7 hours After that, the pressure in the flask was further lowered and maintained at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 197 g of fumaric acid and 0.5 g of 4-tert-butylcatechol were added and held at 210 ° C. for 3 hours, and then the pressure in the flask was lowered to 8.3 kPa. For 4 hours to obtain polyester B. The characteristics of polyester B are shown in Table 1-1.

Production Example R3 (Production of Polyester C)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 3255 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 2,232 g of 2,2-bis (4-hydroxycyclohexyl) propane, 2624 g of terephthalic acid, and 40 g of di (2-ethylhexanoic acid) tin were added, heated to 230 ° C. with stirring in a nitrogen atmosphere, and maintained for 8 hours. After that, the pressure in the flask was further lowered and maintained at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 324 g of fumaric acid and 0.5 g of 4-tert-butylcatechol were added, and after maintaining at 210 ° C. for 5 hours, the pressure in the flask was lowered to 8.3 kPa. For 4 hours to obtain polyester C. The characteristics of polyester C are shown in Table 1-1.

Production Example R4 (Production of Polyester D)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen, and 5520 g of 2,2-bis (4-hydroxycyclohexyl) propane, 2673 g of terephthalic acid, and di (2- 40 g of ethylhexanoic acid) tin was added, heated to 230 ° C. with stirring in a nitrogen atmosphere, held for 9 hours, then the pressure in the flask was lowered and held at 8.3 kPa for an additional 5 hours to obtain polyester. D was obtained. The characteristics of polyester D are shown in Table 1-1.

Production Example R5 (Production of Polyester E)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 4725 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 522 g of 1,4-cyclohexanediol, 2689 g of terephthalic acid, and 40 g of di (2-ethylhexanoic acid) tin were added, heated to 230 ° C. with stirring in a nitrogen atmosphere, and held for 8 hours. The pressure was reduced and held at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 209 g of fumaric acid and 0.5 g of 4-tert-butylcatechol were added and held at 210 ° C. for 3 hours, and then the pressure in the flask was lowered to 8.3 kPa. For 4 hours to obtain polyester E. The characteristics of polyester E are shown in Table 1-1.

Production Example R6 (Production of Polyester F)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 4673 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Into the flask, 641 g of 1,4-cyclohexanedimethanol, 2512 g of terephthalic acid, and 40 g of di (2-ethylhexanoic acid) tin were added, and the temperature was raised to 230 ° C. while stirring for 8 hours in a nitrogen atmosphere. The pressure was reduced and held at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 310 g of fumaric acid and 0.5 g of 4-tert-butylcatechol were added and kept at 210 ° C. for 4 hours, and then the pressure in the flask was lowered to 8.3 kPa. For 4 hours to obtain polyester F. The characteristics of polyester F are shown in Table 1-2.

Production Example R7 (Production of Polyester G)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 6160 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 2045 g of terephthalic acid and 40 g of di (2-ethylhexanoic acid) tin were added, heated to 230 ° C. with stirring in a nitrogen atmosphere, held for 8 hours, and then the pressure in the flask was lowered to 8.3 kPa. Held for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 612 g of fumaric acid and 0.5 g of 4-tert-butylcatechol were added and held at 210 ° C. for 4 hours, and then the pressure in the flask was lowered to 8.3 kPa. For 4 hours to obtain polyester G. Properties of polyester G are shown in Table 1-2.

Production Example R8 (Production of Polyester H)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 4515 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Add 1032 g of 2,2-bis (4-hydroxycyclohexyl) propane, 1999 g of terephthalic acid, and 40 g of di (2-ethylhexanoic acid) tin, raise the temperature to 230 ° C. with stirring in a nitrogen atmosphere, and hold for 7 hours After that, the pressure in the flask was further lowered and maintained at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 399 g of fumaric acid and 0.5 g of 4-tert-butylcatechol were added, and after maintaining at 210 ° C. for 5 hours, the pressure in the flask was lowered to 8.3 kPa. For 5 hours to obtain polyester H. The characteristics of polyester H are shown in Table 1-2.

Production Example R9 (Production of Polyester I)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 4305 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Add 984 g of 2,2-bis (4-hydroxycyclohexyl) propane, 2477 g of terephthalic acid, and 40 g of di (2-ethylhexanoic acid) tin, raise the temperature to 230 ° C. with stirring in a nitrogen atmosphere, and hold for 9 hours After that, the pressure in the flask was further lowered and maintained at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 323 g of fumaric acid and 0.5 g of 4-tert-butylcatechol were added and held at 210 ° C. for 4 hours, and then the pressure in the flask was lowered to 8.3 kPa. For 2 hours to obtain polyester I. The characteristics of polyester I are shown in Table 1-2.

Production Example R10 (Production of Polyester J)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 4253 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Add 972 g of 2,2-bis (4-hydroxycyclohexyl) propane, 2474 g of terephthalic acid, and 40 g of di (2-ethylhexanoic acid) tin, heat to 230 ° C. with stirring in a nitrogen atmosphere, and hold for 9 hours After that, the pressure in the flask was further lowered and maintained at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 338 g of fumaric acid and 0.5 g of 4-tert-butylcatechol were added and held at 210 ° C. for 3 hours, and then the pressure in the flask was lowered to 8.3 kPa. For 2 hours to obtain polyester J. The characteristics of polyester J are shown in Table 1-2.

[Production of aqueous dispersion of polyester resin particles]
Production Example D1 (Production of aqueous dispersion of polyester resin particles A)
A four-necked flask equipped with a nitrogen inlet tube, a reflux condenser, a stirrer (“Three-One Motor BL300” (manufactured by Shinto Kagaku Co., Ltd.)) and a thermocouple is charged with 200 g of polyester A, and methyl ethyl ketone (MEK) at 30 ° C. The resin was dissolved by mixing with 200 g. Subsequently, 33.9 g of 5 mass% sodium hydroxide aqueous solution was added, and it stirred for 30 minutes, and obtained the organic-solvent type slurry. While stirring at 30 ° C., 497 g of deionized water was added dropwise at a rate of 20 mL / min. Thereafter, the temperature was raised to 60 ° C., methyl ethyl ketone was distilled off while gradually reducing the pressure to 80 kPa to 30 kPa, and a part of water was further distilled off. After cooling to 25 ° C., the mixture was filtered through a 150 mesh wire net, the solid content concentration was adjusted to 30% by mass with deionized water, and an aqueous dispersion of polyester resin particles A was obtained. The characteristics of the polyester resin particles A in the obtained aqueous dispersion are shown in Table 2-1.

Production Examples D2 to D10 (Production of aqueous dispersion of polyester resin particles B to J)
In Production Example D1, polyester resin particles B were prepared in the same manner as in Production Example D1, except that the type of polyester and the addition amount of the 5% by mass sodium hydroxide aqueous solution were changed to those shown in Table 2-1 or Table 2-2. An aqueous dispersion of ~ J was obtained. The characteristics of the polyester resin particles in the obtained aqueous dispersion are shown in Table 2-1 or Table 2-2.

[Production of polymer particles containing colorant]
Production Example C1 (Production of aqueous dispersion of water-insoluble polymer particles C1 containing a colorant (pigment))
(1) Synthesis of water-insoluble polymer (anionic polymer) 399 g of benzyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), 91 g of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.), methoxypolyethylene glycol methacrylate (“M-230G”, Shin-Nakamura Chemical Co., Ltd., average addition mole number of oxyethylene group: 23) 140 g, styrene macromonomer (“AS-6S”, manufactured by Toagosei Co., Ltd., solid content: 50%) 140 g are mixed, and monomer mixing A liquid (770 g) was prepared. In a reaction vessel, 15.75 g of methyl ethyl ketone, 0.350 g of a polymerization chain transfer agent (2-mercaptoethanol), and 10% by mass (77 g) of the monomer mixture were mixed and subjected to nitrogen gas replacement.
Meanwhile, 80% (616 g) of the monomer mixture, 2.45 g of the polymerization chain transfer agent, 173.25 g of methyl ethyl ketone, and a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) are added to the dropping funnel. (“V-65”, manufactured by Wako Pure Chemical Industries, Ltd.) 5.6 g was added, and the mixture was heated to 75 ° C. while stirring the mixed solution in the reaction vessel in a nitrogen atmosphere. The mixed solution was added dropwise over 4.5 hours. Then, the remaining 10% by mass (77 g) of the monomer mixture, 0.7 g of the polymerization chain transfer agent, 126 g of methyl ethyl ketone, and 1.4 g of the polymerization initiator were mixed at 75 ° C. as a second drop. It was added dropwise over 7 hours.
After completion of dropping, 2.1 g of the initiator was mixed, heated to 80 ° C., and stirred for 1.5 hours. This initiator was mixed, heated and stirred twice to obtain a polymer solution (polymer weight average molecular weight: 26,000).

(2) Production of aqueous dispersion of pigment-containing polymer particles (pigment-containing anionic polymer particles) C1 The polymer solution obtained by the synthesis of the water-insoluble polymer (anionic polymer) of (1) was dried under reduced pressure. 20 g of the obtained polymer was dissolved in 62.8 g of methyl ethyl ketone, and 5.01 g of 5N sodium hydroxide aqueous solution, 1.13 g of 25 mass% aqueous ammonia and 236.5 g of deionized water were added thereto, and 10-15 The mixture was stirred and mixed at 2000 r / min for 15 minutes using a disper blade at ° C.
Subsequently, 45 g of magenta pigment: PV19 (“Inkjet Magenta E5B02”, manufactured by Clariant Japan Co., Ltd.) and 25 g of magenta pigment: PR122 (“6111T”, manufactured by Dainichi Seika Kogyo Co., Ltd.) were added. The mixture was stirred and mixed at 7000 r / min for 3 hours. The obtained dispersion was filtered through 200 mesh and subjected to a 20-pass dispersion treatment at a pressure of 150 MPa using a microfluidizer “M-110K” (manufactured by Microfluidics, high-pressure homogenizer).
Methyl ethyl ketone was removed from the obtained dispersion at 60 ° C. under reduced pressure, a part of water was further removed, the mixture was centrifuged, and the liquid layer portion was filtered through a filter having a pore size of 5 μm (manufactured by Sartorius Stedim Biotech) to obtain a coarse particle. Particles were removed. Further, 80 g of this dispersion was mixed with 0.2 g of a preservative “Proxel XL2” (Avicia) and 19.8 g of deionized water, sterilized at 70 ° C. for 1 hour, and then cooled to 25 ° C. By filtering with a filter having a pore size of 5 μm, an aqueous dispersion (solid content concentration: 20 mass%, volume average particle size: 133 nm) of polymer particles containing pigment (pigment-containing anionic polymer particles) C1 was obtained. .

Production Example C2 (Production of aqueous dispersion of water-insoluble polymer particles C2 containing a colorant (pigment))
In Production Example C1, 45 g of magenta pigment: PV19 (“Inkjet Magenta E5B02”, manufactured by Clariant Japan Co., Ltd.) and 25 g of magenta pigment: PR122 (“6111T”, manufactured by Dainichi Chemical Industry Co., Ltd.), cyan pigment: PB15: 3 (“TGR-SD”, manufactured by DIC Corporation) In the same manner as in Production Example C1, except for changing to 70 g, an aqueous dispersion (solid content) of pigment-containing polymer particles (pigment-containing anionic polymer particles) C2 Concentration: 20% by mass, volume average particle size: 75 nm).

[Manufacture of water-based ink]
Examples 1 to 9, Comparative Example 1 (Production of water-based inks 1 to 9 and 11)
In a 100 mL screw tube, 20.0 parts by mass of propylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.), 10.0 parts by mass of 1,2-butanediol (manufactured by Wako Pure Chemical Industries, Ltd.), wetting agent “Olfin E1010” ( Made by Nissin Chemical Industry Co., Ltd. (Orphine is a registered trademark), 1.0 part by mass of active ingredient: acetylene glycol surfactant, and 26.6 parts by mass of deionized water are mixed, using a magnetic stirrer, The mixture was stirred at room temperature for 15 minutes to obtain a mixed solution.
Next, 25.7 parts by mass of the aqueous dispersion of the pigment-containing anionic polymer particles C1 obtained in Production Example C1 [4.0 parts by mass in terms of pigment content (in 100 parts by mass of aqueous ink)] was obtained using a magnetic stirrer. While stirring, the total amount of the mixed solution was mixed, and 16.7 parts by weight of an aqueous dispersion of polyester resin particles shown in Table 3-1 or Table 3-2 [5.0 parts by weight in terms of solid content (100 parts by weight of aqueous ink) The mixture was stirred and mixed dropwise with a dropper. Finally, it was filtered with a filter “Minisalto” (registered trademark) (manufactured by Sartorius Stedim Biotech) having a pore diameter of 1.2 μm, and aqueous inks 1 to 9 and 11 were obtained. The evaluation results of the obtained water-based ink are shown in Table 3-1 or Table 3-2.

Example 10 (Production of water-based ink 10)
A water-based ink 10 was obtained in the same manner as in Example 1, except that the aqueous dispersion of the pigment-containing anionic polymer particles C1 was changed to the aqueous dispersion of the pigment-containing anionic polymer particles C2. The evaluation results of the obtained water-based ink are shown in Table 3-2.

  From the results of Tables 3-1 and 3-2, the water-based inks of Examples 1 to 10 using polyester resin particles containing an alicyclic alcohol as an alcohol component are polyesters containing no alicyclic alcohol as an alcohol component. It turns out that it is excellent in the adhesiveness to PVC and the alcohol resistance of printed matter rather than the comparative example 1 which is a water-based ink using a resin particle.

  According to the present invention, a water-based ink having excellent adhesion and alcohol resistance to a resin recording medium and a method for producing the same can be provided, and therefore, it can be applied to fields such as commercial printing.

Claims (8)

A water-based ink containing a colorant and polyester resin particles,
The polyester contained in the polyester resin particles is a polyester (A) obtained by polycondensation of an alcohol component containing a divalent or trivalent alicyclic alcohol and a carboxylic acid component, and the polyester (A) acid value Ri der following 5 mgKOH / g or higher 50 mg KOH / g, the content of the polyester (a) is, in the polyester resin particles, Ru der least 90 mass%, water-based inks.   The water-based ink according to claim 1, wherein the content of the alicyclic alcohol is 5 mol% or more and 100 mol% or less in the alcohol component. The water-based ink according to claim 1 or 2, wherein the alicyclic alcohol is a compound represented by the following general formula (I).

[In General Formula (I), Ring Cy ¹ and Ring Cy ² are each independently an aliphatic hydrocarbon ring having 3 to 12 ring members in the ring structure, and R ⁵ and R ⁶ are each independently A hydrocarbon group having 1 to 8 carbon atoms; d and e are each independently an integer of 0 to 3; and R ¹ and R ² are each independently a hydrogen atom or an alkyl having 1 to 3 carbon atoms. N is 0 or 1, R ³ and R ⁴ are each independently an alkanediyl group having 1 to 3 carbon atoms, and a and b are each independently 0 or 1. ]   The water-based ink according to claim 1, wherein the alicyclic alcohol is hydrogenated bisphenol A. The water-based ink according to any one of claims 1 to 4, wherein the content of the polyester (A) is 98 % by mass or more in the polyester resin particles.   The water-based ink according to any one of claims 1 to 5, which is used for printing on a resin recording medium. A method for producing a water-based ink comprising the following steps (1) and (2) :
Step (1): Polyester (A) having an acid value of 5 mgKOH / g or more and 50 mgKOH / g or less, obtained by polycondensation of an alcohol component containing a divalent or trivalent alicyclic alcohol and a carboxylic acid component. Step of mixing and emulsifying with an aqueous medium to obtain an aqueous dispersion of polyester resin particles Step (2): An aqueous dispersion of polyester resin particles obtained in step (1) and an aqueous dispersion containing a colorant To obtain water-based ink
A method for producing a water-based ink, wherein the polyester resin particles contain 90% by mass or more of the polyester (A).   An ink jet in which the water-based ink according to claim 1 is attached to a resin recording medium by an ink jet recording method, and then the resin recording medium to which the water-based ink is attached is heated to 40 ° C. or higher and 100 ° C. or lower. Recording method.