JP6741225B2 - Water-based ink manufacturing method - Google Patents

Description

The present invention relates to an aqueous ink containing resin particles and a method for manufacturing the same.

In the field of commercial label printing, which is used for product packaging printing and advertising, etc., resin-based recording media such as polyethylene terephthalate, polyvinyl chloride, polyethylene, polypropylene, nylon, etc. have been conventionally treated with solvent-based ink or UV curable ink. Printing has started. On the other hand, from the viewpoint of reduction of environmental load, energy saving, safety, etc., it is required to utilize an inkjet recording method, a flexographic printing method, and further a gravure printing method as a printing method using an aqueous ink. In particular, the ink jet recording method is a recording method in which ink droplets are directly ejected from a very fine nozzle onto a recording member and adhered to obtain characters and images, and full-color conversion is easy and inexpensive. Plain paper can be used as a member, and since it has many advantages that it is non-contact with an object to be printed, it is widely used. Therefore, it has been attempted to utilize the ink jet recording method for the resin recording medium.

In Patent Document 1, as an aqueous ink composition that can be suitably used in an inkjet printer, a pigment, water, a predetermined organic solvent of 10 to 49 mass% of the total amount of the water and the organic solvent, a resin, and an ink composition. A water-based ink composition comprising a surface tension adjusting agent is described.
In Patent Document 2, as an ink composition suitable for printing a mark or an image on a deformable substrate, a polyester, a polyurethane elastomer, water, a cosolvent, an optional surfactant and an optional colorant are used. A extensible ink composition comprising is described.
In Patent Document 3, as an ink composition having excellent adhesion and wet heat resistance of an image obtained by curing, a graft main chain having at least one of a urethane structure and a urea structure and a graft side chain containing a specific structure are used. An ink composition is described, which comprises a graft polymer, a polymerizable compound, and a polymerization initiator, and the content of the monofunctional polymerizable compound in the polymerizable compound is 50% by mass or more.

JP, 2014-101517, A JP, 2005-30853, A JP 2012-201874 A

The polyester resin particles mixed in the water-based ink form a film on the recording medium at the time of printing to improve the adhesion and scratch resistance of the colorant to the non-water-absorptive recording medium. Has a tendency that the water-based ink is less likely to be fixed and the adhesiveness of the printed matter is poorer than that of polyethylene terephthalate (hereinafter also referred to as “PET”), polyvinyl chloride (hereinafter also referred to as “PVC”), and the like. It is considered that this is because nylon has an amide bond portion having a rigid and high polarity and an alkyl skeleton portion which is hydrophobic and relatively soft. Polyurethane is considered to have a high affinity for nylon due to the similarity of the amide bond and the urethane bond, but the film strength was poor and there was a problem with scratch resistance.
An object of the present invention is to provide a water-based ink having excellent adhesion to PET, excellent adhesion to nylon, and scratch resistance, and a method for producing the same.
Further, an object of the present invention is to provide a water-based ink having excellent alcohol resistance and a method for producing the same, in addition to the above problems.

The present invention relates to the following [1] to [4].
[1] A water-based ink containing a colorant and resin particles,
The resin particles contain a composite resin having a polyester segment and a polyurethane segment,
The mass ratio of the polyester segment/polyurethane segment in the composite resin is 20/80 or more and 95/5 or less,
The polyurethane segment is a polyurethane which is a reaction product of a polyol compound containing a polyether polyol and a polyisocyanate compound,
Water-based ink.
[2] The water-based ink according to [1], wherein the polyester segment is a polycondensation product of an alcohol component and a carboxylic acid component, and contains a polyvalent carboxylic acid having a valence of 3 or more as the carboxylic acid component.
[3] The water-based ink according to [2], which contains, as the carboxylic acid component, succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms.
[4] Step 1: Polycondensing an alcohol component and a carboxylic acid component to obtain a polyester,
Step 2: a step of reacting a polyol compound containing a polyether polyol with a polyisocyanate compound to obtain polyurethane,
Step 3: A step of obtaining a composite resin from the polyester obtained in Step 1 and the polyurethane obtained in Step 2.
Step 4: a step of dispersing the composite resin obtained in Step 3 in an aqueous medium to obtain an aqueous dispersion of resin particles, and Step 5: combining the aqueous dispersion of resin particles obtained in Step 4 and a colorant. Has a step of mixing,
A method for producing an aqueous ink, wherein the mass ratio of polyester/polyurethane in step 3 is 20/80 or more and 95/5 or less.

According to the present invention, it is possible to provide a water-based ink having excellent adhesion to PET, excellent adhesion to nylon, and excellent abrasion resistance, and a method for producing the same.
Furthermore, according to [2] or [3] of the present invention, in addition to the above problems, it is possible to provide a water-based ink having excellent alcohol resistance and a method for producing the same.

[Water-based ink]
The water-based ink of the present invention is a water-based ink containing a colorant and resin particles.
In the present invention, the resin particles contain a composite resin having a polyester segment and a polyurethane segment.
The mass ratio of polyester segment/polyurethane segment in the composite resin is 20/80 or more and 95/5 or less, and the polyurethane segment is a reaction product of a polyol compound containing a polyether polyol and a polyisocyanate compound. It is polyurethane.

With the above configuration, it is possible to provide a water-based ink having excellent adhesion to nylon and excellent abrasion resistance, and a method for producing the same. The reason is not clear, but it can be estimated as follows.
The water-based ink of the present invention contains a composite resin having a polyester segment and a polyurethane segment. Polyester having appropriate polarity has excellent film strength and can form an aqueous resin emulsion. By binding polyether polyurethane to this polyester, the polyurethane moiety having a large number of urethane bonds has a high affinity with the amide bond of nylon. By covering, it is considered that the film performance having excellent scratch resistance is exhibited.

[Resin particles]
<Composite resin>
The resin particles contain a composite resin having a polyester segment and a polyurethane segment.
The mass ratio of polyester segment/polyurethane segment in the composite resin is 20/80 or more 95/from the viewpoint of obtaining a water-based ink having excellent adhesiveness to PET, adhesiveness to nylon, and abrasion resistance. 5 or less, preferably 40/60 or more, more preferably 45/55 or more, still more preferably 50/50 or more, and preferably 90/10 or less, more preferably 85/15 or less, further preferably It is 80/20 or less.

[Polyester segment]
The polyester segment is a polyester that is obtained by polycondensing an alcohol component and a carboxylic acid component, that is, a polycondensation product of an alcohol component and a carboxylic acid component.

≪Alcohol component≫
Examples of the alcohol component include diols and polyhydric alcohols having 3 or more valences, and diols are preferable.
Examples of the diol include an aliphatic diol having a main chain carbon number of 2 or more and 12 or less, an aromatic diol, and an alicyclic diol.

Examples of the aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol and 1,9-nonanediol. , 1,10-decanediol, 1,12-dodecanediol and the like.
From the viewpoint of obtaining excellent abrasion resistance, the aliphatic diol is preferably an aliphatic diol having a hydroxy group bonded to a secondary carbon atom and having 3 to 6 carbon atoms.
Examples of the aliphatic diol having a hydroxy group bonded to a secondary carbon atom and having 3 to 6 carbon atoms include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol and 2,3- Butanediol, 1,2-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, 3,3-dimethyl Examples include -1,2-butanediol and the like, preferably at least one selected from 1,2-propanediol and 2,3-butanediol, and more preferably 1,2-propanediol.

Examples of aromatic diols include alkylene oxide adducts of bisphenol A.
The alkylene oxide adduct of bisphenol A is preferably a compound represented by the following general formula (I) from the viewpoint of obtaining excellent scratch resistance.

In the general formula (I), OR ¹ and R ² O are each an alkyleneoxy group, preferably each independently an alkyleneoxy group having 1 to 4 carbon atoms, and more preferably an ethyleneoxy group. Alternatively, it is a propyleneoxy group, more preferably a propyleneoxy group.
x and y correspond to the number of moles of alkylene oxide added. Further, 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 preferably 7 or less, more preferably 5 or less, and further preferably 3 or less. ..
Further, x OR ^1's and y R ² O's may be the same or different, but are preferably the same from the viewpoint of improving the fixability of the ink to the recording medium. 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 and an ethylene oxide adduct of bisphenol A, more preferably a propylene oxide adduct of bisphenol A.

Examples of the alicyclic diol include cyclohexanediol, hydrogenated bisphenol A, cyclohexanedimethanol and the like.

Among them, the alcohol component is preferably an alkylene oxide adduct of bisphenol A, hydrogenated bisphenol A, and hydroxy bonded to a secondary carbon atom, from the viewpoint of obtaining excellent adhesion to various resin recording media. It is at least one selected from aliphatic diols having 3 to 6 carbon atoms, and more preferably alkylene oxide adducts of bisphenol A, and 3 carbon atoms having a hydroxy group bonded to a secondary carbon atom. At least one selected from aliphatic diols of 6 or more and 6 or less, more preferably at least one selected from propylene oxide adducts of bisphenol A and 1,2-propanediol.
Further, from the viewpoint of obtaining a water-based ink having excellent adhesion to various resin recording media, scratch resistance and alcohol resistance, it is preferably bound to an alkylene oxide adduct of bisphenol A and a secondary carbon atom. It is at least one selected from aliphatic diols having a hydroxy group and having 3 to 6 carbon atoms, more preferably an alkylene oxide adduct of bisphenol A, and even more preferably a propylene oxide adduct of bisphenol A.
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 of the polyester is preferably 50 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more from the viewpoint of obtaining excellent scratch resistance. And preferably not more than 100 mol %.
The content of the aliphatic diol having a hydroxy group bonded to a secondary carbon atom and having 3 to 6 carbon atoms in the alcohol component of the polyester is preferably 50 mol% or more, from the viewpoint of obtaining excellent scratch resistance. It is more preferably 80 mol% or more, still more preferably 90 mol% or more, and preferably 100 mol% or less.

<<Carboxylic acid component>>
Examples of the carboxylic acid component include dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, their acid anhydrides, and their alkyl esters having 1 to 3 carbon atoms, among which the viewpoint of obtaining excellent adhesion. Therefore, it preferably contains a dicarboxylic acid, more preferably a dicarboxylic acid.
The carboxylic acid component includes not only carboxylic acids but also their anhydrides and their alkyl esters having 1 to 3 carbon atoms. That is, in the present specification, when only the name of carboxylic acid is described, it is assumed that the carboxylic acid anhydride and the alkyl ester having 1 to 3 carbon atoms are also included.

Examples of the dicarboxylic acid include aromatic dicarboxylic acid, aliphatic dicarboxylic acid, and alicyclic dicarboxylic acid.
Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid and the like. From the viewpoint of improving scratch resistance, terephthalic acid is preferable.
Examples of the aliphatic dicarboxylic acid include fumaric acid, adipic acid, sebacic acid, maleic acid, azelaic acid, succinic acid, succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or 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, at least one selected from fumaric acid, adipic acid, sebacic acid, and dodecenylsuccinic acid is preferable, and fumaric acid is more preferable, from the viewpoint of obtaining excellent adhesion.
Examples of the alicyclic dicarboxylic acid include cyclohexanedicarboxylic acid.
Examples of the trivalent or higher polycarboxylic acid include trimellitic acid, 2,5,7-naphthalenetricarboxylic acid and pyromellitic acid.

The carboxylic acid component is preferably isophthalic acid, terephthalic acid, fumaric acid, adipic acid, from the viewpoint of obtaining a water-based ink having excellent adhesion to PET, excellent adhesion to nylon, and excellent scratch resistance. , At least one selected from sebacic acid and dodecenylsuccinic acid, and more preferably at least one selected from terephthalic acid and fumaric acid.
The carboxylic acid components may be used alone or in combination of two or more.

From the viewpoint of obtaining excellent alcohol resistance in addition to adhesiveness and scratch resistance to a resin recording medium, it is preferable to contain a polyvalent carboxylic acid having a valence of 3 or more as the carboxylic acid component of the polyester. By using a trivalent or higher polycarboxylic acid, it is possible to impart a branched/crosslinked structure to the polyester segment, which is considered to contribute to the improvement of alcohol resistance.
The trivalent or higher polycarboxylic acid is preferably a trivalent or higher aromatic carboxylic acid from the viewpoint of obtaining excellent alcohol resistance.
The number of carbon atoms of the trivalent or higher aromatic carboxylic acid is preferably 8 or more, more preferably 9 or more, and preferably 16 or less, more preferably 14 or less from the viewpoint of obtaining excellent alcohol resistance.
The valence of the polycarboxylic acid is preferably trivalent, from the viewpoint of obtaining excellent alcohol resistance.
From the viewpoint of obtaining excellent alcohol resistance in addition to adhesion and scratch resistance to a resin recording medium, trimellitic acid and its anhydride are preferable, and trimellitic anhydride is more preferable.
The content of the trivalent or higher polyvalent carboxylic acid in the carboxylic acid component of the polyester segment is preferably 2 from the viewpoint of obtaining excellent alcohol resistance in addition to adhesion to the resin recording medium and scratch resistance. It is at least mol%, more preferably at least 5 mol%, further preferably at least 8 mol%, and preferably at most 50 mol%, more preferably at most 30 mol%, still more preferably at most 20 mol%.

Further, from the viewpoint of obtaining excellent alcohol resistance in addition to adhesiveness and scratch resistance to a resin recording medium, the carboxylic acid component is an alkyl group having 1 to 20 carbon atoms or 2 to 20 carbon atoms. It preferably contains succinic acid substituted with an alkenyl group (hereinafter, also simply referred to as “substituted succinic acid”), and more preferably contains a trivalent or higher polyvalent carboxylic acid and a substituted succinic acid.

When the substituent of the substituted succinic acid used in the present invention is an alkyl group, the carbon number of the alkyl group is preferably 4 or more, more preferably 6 or more, further preferably 8 or more, and preferably 18 or less, It is more preferably 16 or less, still more preferably 14 or less.
When the substituent of the substituted succinic acid used in the present invention is an alkenyl group, the carbon number of the alkenyl group is preferably 4 or more, more preferably 6 or more, further preferably 8 or more, and preferably 18 Or less, more preferably 16 or less, still more preferably 14 or less.
Specific examples of the substituted succinic acid include dodecyl succinic acid, dodecenyl succinic acid and octenyl succinic acid. Among these, in addition to adhesion and scratch resistance to the resin recording medium, from the viewpoint of obtaining excellent alcohol resistance, at least one selected from the group consisting of dodecyl succinic acid and dodecenyl succinic acid, More preferably, it is at least one selected from the group consisting of dodecyl succinic anhydride and dodecenyl succinic anhydride, and even more preferably dodecenyl succinic anhydride.

The content of the substituted succinic acid is preferably 10 mol% or more, more preferably 20 mol% or more, in the carboxylic acid component, from the viewpoint of obtaining excellent alcohol resistance in addition to adhesiveness and scratch resistance to the resin recording medium. It is at least mol%, more preferably at least 25 mol%, and preferably at most 50 mol%, more preferably at most 45 mol%, still more preferably at most 40 mol%.

The equivalent ratio (COOH group/OH group) of the carboxy group (COOH group) of the carboxylic acid component to the hydroxy group (OH group) of the alcohol component in the polyester segment has excellent adhesion to PET and further adhesion to nylon. And from the viewpoint of obtaining a water-based ink having excellent scratch resistance, it is preferably 0.65 or more, more preferably 0.80 or more, and preferably 1.2 or less, more preferably 1.1 or less. is there.

The glass transition temperature of the polyester segment is preferably 40° C. or higher, more preferably 45° C. or higher, even more preferably 50° C. or higher, from the viewpoint of improving scratch resistance, and the adhesion to a non-water-absorptive recording medium. From the viewpoint of improving the temperature, it is preferably 100° C. or lower, more preferably 90° C. or lower, further preferably 80° C. or lower, and further preferably 70° C. or lower.
The softening point of the polyester segment is preferably 70° C. or higher, more preferably 80° C. or higher, further preferably 90° C. or higher, from the viewpoint of improving scratch resistance, and the adhesion to a non-water-absorptive recording medium. From the viewpoint of improvement, the temperature is preferably 165° C. or lower, more preferably 130° C. or lower, and further preferably 110° C. or lower.
Further, the softening point of the polyester segment is preferably 80° C. or higher, more preferably 100° C. or higher, further preferably 110° C. or higher, from the viewpoint of improving scratch resistance and alcohol resistance, and non-water-absorptive recording. From the viewpoint of improving the adhesion to the medium and the alcohol resistance, the temperature is preferably 165°C or lower, more preferably 140°C or lower, and further preferably 130°C or lower.

The hydroxyl value of the polyester segment is preferably 5 mgKOH/g or more, more preferably 10 mgKOH/g or more, further preferably 12 mgKOH/g or more, from the viewpoint of reactivity with the polyurethane segment and from the viewpoint of improving scratch resistance. It is preferably 15 mgKOH/g or more, and preferably 80 mgKOH/g or less, more preferably 60 mgKOH/g or less, further preferably 40 mgKOH/g or less, further preferably 30 mgKOH/g or less.
The acid value of the polyester segment is preferably 5 mgKOH/g or more, more preferably 10 mgKOH/g or more, further preferably 15 mgKOH/g, from the viewpoint of improving the dispersion stability of the composite resin particles and the viewpoint of improving scratch resistance. It is above, and preferably 35 mgKOH/g or less, more preferably 30 mgKOH/g or less, further preferably 25 mgKOH/g or less.

The number average molecular weight of the polyester is preferably 1,000 or more, more preferably 2,000 or more, still more preferably 2,500 or more, from the viewpoint of improving the adhesion to a non-water-absorbent recording medium and the scratch resistance. , And preferably 10,000 or less, more preferably 7,000 or less, still more preferably 5,000 or less.

The glass transition temperature, softening point, hydroxyl value, acid value and number average molecular weight of the above polyester segment are values obtained by the method described in Examples for the polyester as the raw material. When two or more polyesters are mixed and used, the glass transition temperature, softening point, hydroxyl value, acid value and number average molecular weight thereof are determined as a mixture of two or more polyesters by the method described in the examples. It is the obtained value.
The glass transition temperature, the softening point, the hydroxyl value, the acid value and the number average molecular weight of the polyester segment are all types of monomers used in the production of polyester, the compounding ratio, the temperature of polycondensation, and the reaction time is adjusted appropriately. You can get what you want.
The polyester segment may be used alone or in combination of two or more.

[Polyurethane segment]
The polyurethane segment has excellent adhesion to PET, further adhesion to nylon, and from the viewpoint of obtaining a water-based ink having excellent scratch resistance, a polyol compound containing a polyether polyol is reacted with a polyisocyanate compound. That is, the polyurethane is a reaction product of a polyol compound containing a polyether polyol and a polyisocyanate compound.

≪Polyol compound≫
The polyol compound includes a polyether polyol from the viewpoint of obtaining a water-based ink having excellent adhesion to PET, adhesion to nylon, and scratch resistance.

(Polyether polyol)
The polyether polyol has an alkyleneoxy group as a repeating unit.
The carbon number of the alkyleneoxy group of the polyether polyol is preferably 2 or more, and more preferably from the viewpoint of obtaining an aqueous ink having excellent adhesion to PET, adhesion to nylon, and abrasion resistance. It is 3 or more, more preferably 4 or more, and preferably 8 or less, more preferably 7 or less, still more preferably 6 or less.
Examples of the polyether polyol include polyethylene glycol, polypropylene glycol and polytetramethylene glycol. Among these, polytetramethylene glycol is preferable from the viewpoint of obtaining an aqueous ink having excellent adhesion to PET, excellent adhesion to nylon, and excellent scratch resistance.

The weight average molecular weight (Mw) of the polyether polyol is preferably 500 or more, more preferably 600 or more, more preferably 700 or more, more preferably 800 or more from the viewpoint of improving scratch resistance, and non-water absorption. From the viewpoint of improving the adhesion to the recording medium, it is preferably 5,000 or less, more preferably 4,000 or less, still more preferably 3,000 or less.

Commercially available polyether polyols include polytetramethylene oxide 1,000 (polytetramethylene glycol, weight average molecular weight 1,000) manufactured by Wako Pure Chemical Industries, Ltd., polytetramethylene oxide 650 (polytetramethylene glycol, weight). Average molecular weight 650), polytetramethylene oxide 1,400 (polytetramethylene glycol, weight average molecular weight 1,400), PTMG650 (polytetramethylene glycol, weight average molecular weight 650), PTMG850 (polytetramethylene) manufactured by Mitsubishi Chemical Corporation. Glycol, weight average molecular weight 850), PTMG1000 (polytetramethylene glycol, weight average molecular weight 1,000), PTMG1300 (polytetramethylene glycol, weight average molecular weight 1,300), PTMG1500 (polytetramethylene glycol, weight average molecular weight 1, 500) and the like.

(Diol having a carboxy group)
As the polyol compound, in addition to the polyether polyol, it is possible to use the diols and the like exemplified above as the alcohol component constituting the polyester segment, but to introduce a carboxy group into the polymer from the viewpoint of the emulsifying property of the polyurethane and the composite resin. It is preferable to use a diol having a carboxy group together.
Examples of the diol component having a carboxy group include 2,2-bis(hydroxymethyl)butyric acid, 2,2-bis(hydroxymethyl)propionic acid, and tartaric acid.

≪Polyisocyanate compound≫
Examples of the polyisocyanate compound include aliphatic diisocyanates, aromatic diisocyanates, and prepolymer-type, isocyanurate-type, urea-type, and carbodiimide-type modified products of these diisocyanates.
Examples of the aliphatic diisocyanate include alicyclic diisocyanate and chain aliphatic diisocyanate.
Examples of the alicyclic diisocyanate include isophorone diisocyanate (hereinafter also referred to as “IPDI”), 4,4′-dicyclohexylmethane diisocyanate (hereinafter also referred to as “DCI”), 4-methyl-1,3-cyclohexylene diisocyanate, 1,2-bis(isocyanatomethyl)cyclohexane etc. are mentioned.
Examples of the chain aliphatic diisocyanate include straight chain aliphatic diisocyanate and branched chain aliphatic diisocyanate, and more specifically, hexamethylene diisocyanate (hereinafter also referred to as “HMDI”) and the like.
Examples of aromatic diisocyanates include 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, and 3,3′-dimethyl-4,4′-biphenylene diisocyanate can be mentioned.
Among the above polyisocyanate compounds, from the viewpoint of improving the adhesion to nylon, aliphatic diisocyanates are preferable, alicyclic diisocyanates are more preferable, and at least one selected from isophorone diisocyanate and 4,4′-dicyclohexylmethane diisocyanate. Is more preferable.

[Molar ratio (OH/NCO)]
In the raw material monomer of the polyurethane segment, the hydroxyl group of the polyol compound and the molar ratio of the isocyanate group of the polyisocyanate component (OH/NCO), from the viewpoint of increasing the molecular weight of the polyurethane segment, and from the viewpoint of leaving the isocyanate group in the polyurethane, It is preferably 1.0 or less, more preferably less than 1.0, and preferably 0.5 or more, more preferably 0.7 or more.
The polyurethane segments may be used alone or in combination of two or more.

The composite resin used in the present invention can be produced by steps 1 to 3 in the method for producing an aqueous ink of the present invention described below.

<Physical properties of composite resin>
The glass transition temperature of the composite resin is preferably 20° C. or higher, more preferably 25° C. or higher, even more preferably 30° C. or higher, from the viewpoint of improving scratch resistance, and the adhesion to PET and nylon. From the viewpoint of improving adhesion, the temperature is preferably 80°C or lower, more preferably 60°C or lower, and further preferably 50°C or lower.
The number average molecular weight of the composite resin is preferably 1,000 or more, more preferably 1,500 or more, still more preferably 2, from the viewpoint of improving the adhesion to PET, the adhesion to nylon, and the scratch resistance. It is 000 or more, and preferably 10,000 or less, more preferably 9,000 or less, and further preferably 8,000 or less.

The acid value of the composite resin is preferably 5 mgKOH/g or more, more preferably 10 mgKOH/g or more, further preferably 15 mgKOH/g or more from the viewpoint of improving the dispersion stability of the resin particles and the viewpoint of improving scratch resistance. And preferably 50 mgKOH/g or less, more preferably 40 mgKOH/g or less, still more preferably 35 mgKOH/g or less.

The content of the polyester segment in the composite resin is preferably 20% by mass or more, and more preferably from the viewpoint of obtaining a water-based ink having excellent adhesion to PET, adhesiveness to nylon, and abrasion resistance. Is 40% by mass or more, more preferably 45% by mass or more, further preferably 50% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, further preferably 85% by mass or less, and It is preferably 80% by mass or less.
The content of the polyurethane segment in the composite resin is preferably 5% by mass or more, more preferably from the viewpoint of obtaining a water-based ink having excellent adhesion to PET, adhesion to nylon, and abrasion resistance. Is 10% by mass or more, more preferably 15% by mass or more, further preferably 20% by mass or more, and preferably 80% by mass or less, more preferably 60% by mass or less, further preferably 55% by mass or less, and It is preferably 50% by mass or less.

The content of the constitutional unit derived from the polyether polyol in the composite resin is preferably 3 mass from the viewpoint of obtaining a water-based ink having excellent adhesiveness to PET, adhesiveness to nylon, and abrasion resistance. % Or more, more preferably 6% by mass or more, further preferably 10% by mass or more, further preferably 15% by mass or more, and preferably 65% by mass or less, more preferably 60% by mass or less, further preferably 50% by mass or less. It is not more than 40% by mass, preferably not more than 45% by mass, more preferably not more than 40% by mass.
The content of the constitutional unit derived from the polyisocyanate compound in the composite resin is preferably 2% by mass from the viewpoint of obtaining a water-based ink having excellent adhesiveness to PET, adhesiveness to nylon, and abrasion resistance. % Or more, more preferably 4% by mass or more, further preferably 5% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, still more preferably 13% by mass or less, further preferably 10% by mass or less. It is not more than mass %.

From the viewpoint of obtaining an aqueous ink having excellent adhesion to PET, adhesion to nylon, and abrasion resistance, the content of polyester segment [PES] (mass %) in the composite resin, polyether polyol The content [PEP] (mass %) of the constituent unit derived from the polyisocyanate compound and the content [PIS] (mass%) of the constituent unit derived from the polyisocyanate compound preferably have the following relationships. In the following relationship, the difference in content of each structural unit is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more.
[PES]>[PEP]>[PIS]

The resin particles may contain a resin other than the composite resin, for example, a resin such as a styrene-acrylic copolymer, an epoxy resin, or a polycarbonate, as long as the effect of the present invention is not impaired.
Further, the resin particles may contain, as an optional component, a reinforcing filler such as a fibrous substance, an additive such as an antioxidant and an antioxidant, etc., as long as the effect of the present invention is not impaired.

The content of the composite resin in the resin particles is preferably 60% by mass or more, more preferably 80% by mass or more, and further preferably from the viewpoint of improving the adhesion to PET, the adhesion to nylon, and the scratch resistance. Is 90% by mass or more, more preferably 98% by mass or more, and further preferably 100% by mass.

The content of the resin particles in the ink is preferably 0.5% by mass or more, more preferably 1% by mass or more, from the viewpoint of improving the adhesion to PET, the adhesion to nylon, and the scratch resistance. It is preferably 3% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less.

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

The pigment may be either an inorganic pigment or an organic pigment.
Examples of the inorganic pigment include carbon black and metal oxides. When used in black ink, carbon black is preferable.
Examples of the 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. Phthalocyanine pigments, quinacridone pigments, and 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. Pigment Green, and one or more types of each product number selected from the group consisting of Pigment Green.

In the present invention, a self-dispersion pigment can also be used. The self-dispersion pigment is a hydrophilic functional group (an anionic hydrophilic group such as a carboxy group or a sulfonic acid group, or a cationic hydrophilic group such as a quaternary ammonium group), which is directly or other atomic group. It means an inorganic pigment or an organic pigment which can be dispersed in an aqueous medium without using a surfactant or a resin by being bonded to the surface of the pigment through the pigment. Here, examples of the other atomic group include an alkanediyl group having 1 to 12 carbon atoms, a phenylene group, a naphthylene group, and the like.
The above-mentioned pigments can be used alone or in combination of two or more kinds and mixed at an arbitrary 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 hydrophobic dyes include oil-soluble dyes and disperse dyes.
The above colorants can be used alone or in combination of two or more kinds and mixed at an arbitrary ratio.

The content of the colorant in the ink is preferably 1% by mass or more, more preferably 2% by mass or more, further preferably 3% by mass or more, from the viewpoint of improving the dispersion stability of the ink and the image density. , Preferably 25% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less.
The mass ratio of the colorant to the resin particles [colorant/resin particle] is preferably 10/in the ink from the viewpoint of improving the ejection property of the water-based ink and improving the adhesiveness to various resin recording media. 90 or more, more preferably 20/80 or more, still 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, further preferably 60. /40 or less, more preferably 50/50 or less.

[Polymer Particles Containing Colorant]
The colorant preferably uses a surfactant and a polymer, and is preferably used as polymer particles containing the colorant.
The polymer particles containing the colorant will be described below.

The volume average particle diameter (D _V ) of the polymer particles containing a colorant is preferably 40 nm or more, more preferably 50 nm or more, and preferably 200 nm or less, more preferably from the viewpoint of improving the image density of the ink. Is 150 nm or less. The volume average particle diameter (D _V ) of the polymer particles containing a colorant is measured by the dynamic light scattering method, and specifically, it is measured by the method of the examples.

From the viewpoint of improving the water dispersibility of the polymer particles in the ink and the image density of the ink, it is preferable to use a water-insoluble polymer as the polymer particles containing the colorant. Here, the "water-insoluble polymer" refers to a polymer having a dissolved amount of 10 g or less when dissolved in 100 g of water at 25°C after drying at 105°C for 2 hours to reach a constant amount of the polymer. The amount of dissolution is preferably 5 g or less, more preferably 1 g or less. In the case of an anionic polymer, the amount of dissolution is the amount of dissolution when the anionic group of the polymer is 100% neutralized with sodium hydroxide.
Examples of the water-insoluble polymer include polyester, polyurethane, and vinyl-based polymers. From the viewpoint of improving the storage stability of ink, it is preferably obtained by addition polymerization of vinyl monomer (vinyl compound, vinylidene compound, vinylene compound). It is a 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 the 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, 2-methacryloyloxymethylsuccinic acid and the like.
Among the anionic monomers, from the viewpoint of improving the dispersion stability of the polymer particles containing the colorant in the ink, it is preferably at least one selected from carboxylic acid monomers, more preferably acrylic acid and methacrylic acid. ..
The amount of the ionic monomer component is preferably 2% by mass or more, more preferably 5% by mass or more, more preferably 5% 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. It is preferably 8% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, and further preferably 25% by mass or less.

As the hydrophobic monomer, an alkyl (meth)acrylate having an alkyl group having 1 to 22 carbon atoms, more preferably 6 to 18 carbon atoms; a styrene-based monomer such as styrene, 2-methylstyrene, divinylbenzene; benzyl ( Examples thereof include aromatic group-containing (meth)acrylates such as (meth)acrylate and phenoxyethyl (meth)acrylate, and styrene and benzyl (meth)acrylate are preferable.
In addition, "(meth)acrylate" shows at least 1 sort(s) chosen from an acrylate and a methacrylate.
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 preferably 98% by mass or less, more preferably 80% by mass or less.

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

The monomer components of the vinyl polymer may be used alone or in combination of two or more.

The weight average molecular weight of the water-insoluble polymer is preferably 5,000 or more, and more preferably from the viewpoint of improving the dispersion stability of the polymer particles containing the colorant in the ink and improving 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, further preferably 300,000 or less, further preferably 200,000 or less. The weight average molecular weight can be measured by the method described in Examples.

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

The content of the polymer particles containing a colorant is preferably 1% by mass or more, more preferably 2% by mass or more, further preferably 3% by mass in the ink from the viewpoint of improving the dispersion stability and the image density of the ink. It is above, and preferably 40% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less.

(Method for producing polymer particles containing colorant)
Polymer particles containing a colorant, for example, a water-insoluble polymer, an organic solvent, a colorant, water, and if necessary, a dispersion containing a mixture containing a neutralizing agent, a surfactant, etc. is subjected to a dispersion treatment to contain the colorant. After obtaining a dispersion of polymer particles, the organic solvent is removed from the dispersion to obtain an aqueous dispersion of polymer particles containing a colorant.

There is no limitation on the organic solvent that dissolves the water-insoluble polymer, but aliphatic alcohols having 1 to 3 carbon atoms, ketones having 3 to 5 carbon atoms, ethers, esters and the like are preferable, and ketones are more preferable. Methyl ethyl ketone is more preferred. When the water-insoluble polymer is synthesized by the solution polymerization method, the solvent used for the polymerization may be used as it is.
When the water-insoluble polymer is an anionic polymer, a neutralizing agent may be used to neutralize the anionic groups in the water-insoluble polymer. When a neutralizing agent is used, it is preferably neutralized so that the pH becomes 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 the polymer particles containing the colorant, the colorant is preferably 5% by mass or more, more preferably 10% by mass, from the viewpoint of improving the 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 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.

The dispersion method of the dispersion is not particularly limited. It is preferable to control the volume average particle diameter (D _V ) of the polymer particles containing the colorant to a desired particle diameter by using a known kneader or disperser.

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. Further, from the viewpoint of improving the productivity and storage stability of the aqueous dispersion, polymer particles containing a colorant are subjected to a crosslinking treatment, or optionally added to the aqueous ink described below, an organic solvent, a preservative, Various additives such as a fungicide may be added to the aqueous dispersion of polymer particles containing a colorant.

The solid content concentration of the aqueous dispersion of the polymer particles containing a colorant is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably from the viewpoint of improving the productivity and storage stability of the aqueous dispersion. Is 15% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less, further preferably 40% by mass or less, and further preferably 35% by mass or less.

[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 adjusting agent, an antifoaming agent, an antiseptic agent, a fungicide, a rust preventive agent, a pH adjusting agent, an antioxidant, and an ultraviolet absorbing agent. Various additives such as agents can be added.
Examples of the organic solvent include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, cyclic carbonates, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.

As the polyhydric alcohol, 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-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol and the like.
As the polyhydric alcohol alkyl ether, 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, 1,3-dimethylimidazolidinone and ε-caprolactam.
Examples of the amide include formamide, N-methylformamide, N,N-dimethylformamide and the like.
Examples of amines include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine and the like.
Examples of the sulfur-containing compound include dimethyl sulfoxide, sulfolane, thiodiethanol and thiodiglycol.
The organic solvent may be used alone or in combination of two or more kinds, but it is preferable to use two or more kinds in combination.
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, 1 , 2-hexanediol, glycerin, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and 2-pyrrolidone are preferably used alone or in combination of two or more.

The content of the organic solvent in the ink is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 40% by mass or less, and more preferably from the viewpoint of improving the dispersion stability of the ink. Is 35% by mass or less.

Examples of the surfactant include nonionic surfactants, anionic surfactants, amphoteric surfactants, silicone-based surfactants and fluorine-based surfactants.
Examples of the nonionic surfactant include glycol ethers such as polyoxyethylene alkyl ether, acetylene glycol, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, and polyoxyethylene sorbitan fatty acid ester.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, succinic acid ester sulfonate, lauryl salt, and salt of polyoxyethylene alkyl ether sulfate.
As the amphoteric surfactant, for example, lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, lauryl dimethylamine oxide, myristyl dimethylamine oxide, stearyl dimethylamine oxide, dihydroxyethyl lauryl amine oxide, etc. Is mentioned.

Examples of the silicone-based surfactant include polyester-modified silicone and polyether-modified silicone.
Examples of fluorine-based surfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and the like.
The surfactants may be used alone or in combination of two or more.
Among these, at least one selected from nonionic surfactants and silicone-based surfactants is preferable, and at least one selected from glycol ethers, acetylene glycols, polyester-modified silicones, and polyether-modified silicones is more preferable. At least one selected from ether and acetylene glycol is more preferred, and at least one selected from acetylene glycol and polyoxyethylene alkyl ether is more preferred.

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

Examples of the defoaming agent include silicone-based defoaming agents, polyether-based defoaming agents, and fatty acid ester-based defoaming agents.
Examples of the preservatives and antifungal agents include 1,2-benzisothiazolin-3-one, sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxide sodium, sodium benzoate, and pentachlorophenol sodium. Is mentioned.
Examples of the rust preventive agent include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and the like.

The pH adjuster is not particularly limited as long as it can adjust the pH 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 Examples thereof include ammonium hydroxide.
Examples of antioxidants include phenolic antioxidants (including hindered phenolic antioxidants), amine antioxidants, sulfur antioxidants, phosphorus antioxidants, and the like.
Examples of the UV absorber include benzophenone-based UV absorbers, benzotriazole-based UV absorbers, salicylate-based UV absorbers, and the like.

[Method for producing water-based ink]
The aqueous ink of the present invention can be obtained, for example, by mixing an aqueous dispersion of resin particles and an aqueous dispersion containing a colorant.
Here, you may further mix at least 1 sort(s) of the above-mentioned arbitrary component. For mixing, for example, various stirring devices can be used.
The preferable content of the resin particles and the colorant in the water-based ink is as described above.

The content of water contained in the water-based ink is preferably 30% by mass or more, more preferably 40% by mass or more, still more preferably 50% by mass or more, and further preferably from the viewpoint of maintaining the viscosity of the ink appropriately. It is 55 mass% or more, and preferably 90 mass% or less, more preferably 80 mass% or less, and further preferably 75 mass% or less.

The method for producing the water-based ink of the present invention, from the viewpoint of obtaining a water-based ink having excellent adhesion to PET, further adhesion to nylon, and excellent abrasion resistance,
Step 1: a step of polycondensing an alcohol component and a carboxylic acid component to obtain a polyester,
Step 2: a step of reacting a polyol compound containing a polyether polyol with a polyisocyanate compound to obtain polyurethane,
Step 3: A step of obtaining a composite resin from the polyester obtained in Step 1 and the polyurethane obtained in Step 2.
Step 4: a step of dispersing the composite resin obtained in Step 3 in an aqueous medium to obtain an aqueous dispersion of resin particles,
Step 5: A step of mixing the aqueous dispersion of resin particles obtained in Step 4 and a colorant,
A method for producing an aqueous ink having a is preferable. The mass ratio of polyester/polyurethane in step 3 is preferably 20/80 or more and 95/5 or less.

<Step 1>
The polyester obtained in step 1 is a raw material for the polyester segment of the composite resin.
In step 1, for example, the alcohol component and the carboxylic acid component are subjected to polycondensation 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. It can be manufactured.

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 bistriethanolaminate can be used.
The amount of the esterification catalyst used is not particularly limited, but is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, based on 100 parts by mass of the total amount of the carboxylic acid component and the alcohol component. , And preferably 1.5 parts by mass or less, more preferably 1.0 parts by mass or less.

Further, a radical polymerization inhibitor can be used if necessary. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The amount of the radical polymerization inhibitor used is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, and preferably 100 parts by mass of the total amount of the carboxylic acid component and the alcohol component. The amount is 0.5 parts by mass or less, more preferably 0.1 parts by mass or less.

<Step 2>
The polyurethane obtained in step 2 is a raw material for the urethane segment of the composite resin.
In step 2, the polyurethane is preferably an isocyanate group-containing polyurethane from the viewpoint of subsequent reaction with polyester.
In step 2, for example, it can be produced by reacting the polyol compound containing the polyether polyol with the polyisocyanate compound in an inert gas atmosphere, if necessary, using a urethanization catalyst.

As the urethane-forming catalyst, a catalyst such as a tin compound such as dibutyltin oxide or di(2-ethylhexanoic acid) tin, or a titanium compound such as titanium diisopropylate bistriethanolaminate can be used.
The amount of the urethanization catalyst used is not limited, but is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, based on 100 parts by mass of the total amount of the polyol compound and the polyisocyanate compound, and , Preferably 1.5 parts by mass or less, more preferably 1.0 parts by mass or less.
The molar ratio (OH/NCO) of the hydroxyl group and the isocyanate group in the raw material monomer of step 2 is preferably 1.0 or less, more preferably from the viewpoint of leaving the isocyanate group in the polyurethane for bonding with the polyester. It is less than 1.0, and preferably 0.5 or more, more preferably 0.7 or more.

The reaction between the polyol compound and the polyisocyanate compound is preferably carried out in an organic solvent. As the organic solvent, various known organic solvents having no functional group capable of reacting with an isocyanate group, such as acetone, methyl ethyl ketone, and tetrahydrofuran, can be used.

From the viewpoint of reactivity, the amount of the organic solvent used when using an organic solvent is preferably 30 parts by mass or more, and more preferably 50 parts by mass or more, relative to 100 parts by mass of the total amount of the polyol compound and the polyisocyanate compound. , More preferably 70 parts by mass or more, and preferably 500 parts by mass or less, more preferably 300 parts by mass or less, still more preferably 200 parts by mass or less.
The reaction temperature is preferably 20° C. or higher and 100° C. or lower and not higher than the boiling point of the solvent.
The reaction time is preferably 1 hour or longer, more preferably 2 hours or longer, still more preferably 3 hours or longer, and preferably 24 hours or shorter, more preferably 12 hours or shorter, still more preferably 6 hours or shorter.

<Step 3>
In step 3, a composite resin can be manufactured by binding polyester and polyurethane.
Heat-mixing polyurethane having an isocyanate group and polyester having a hydroxyl group, adding a diisocyanate compound to polyurethane having a hydroxyl group and polyester having a hydroxyl group, and heat-mixing, heat-mixing polyurethane having a hydroxyl group with an isocyanate compound and polyester in advance It can be obtained by a method such as heating and mixing the polyester containing an isocyanate group obtained by heating.

In Step 3, the mass ratio of polyester/polyurethane is 20/80 or more and 95/5 or less from the viewpoint of obtaining a water-based ink having excellent adhesion to PET, adhesion to nylon, and abrasion resistance. Is preferably 40/60 or more, more preferably 45/55 or more, still more preferably 50/50 or more, and preferably 90/10 or less, more preferably 85/15 or less, further preferably 80/ It is 20 or less.
Also in the step 3, it can be produced by reacting with a urethanization catalyst if necessary. As the urethanization catalyst, the same one as in step 2 can be used.
The reaction temperature in step 3 is preferably 20° C. or higher and 100° C. or lower and not higher than the boiling point of the solvent.
The reaction time in step 3 is preferably 0.2 hours or longer, more preferably 0.5 hours or longer, still more preferably 1 hour or longer, and preferably 6 hours or shorter, more preferably 5 hours or shorter, and further preferably. Is less than 4 hours.

The resulting composite resin may be subjected to the following step 4 as an organic solvent solution, and from the viewpoint of productivity, it is preferable to use it as an organic solvent solution. From the viewpoint of improving the productivity of the ink, the solid content concentration of the organic resin solution of the composite resin is preferably 20% by mass or more, more preferably 30% by mass or more, further preferably 40% by mass or more, and preferably Is 85 mass% or less, more preferably 75 mass% or less, and further preferably 65 mass% or less.
The solid content is the total amount of non-volatile components such as the above-mentioned optional components such as a resin, a surfactant that can be added if necessary, and a colorant.

<Step 4>
Step 4 is a step of dispersing the composite resin obtained in Step 3 in an aqueous medium to obtain an aqueous dispersion of resin particles.
In step 4, a step (phase inversion emulsification method) in which an aqueous medium is gradually added to the composite resin solution in which the composite resin is dissolved in an organic solvent to cause phase inversion and emulsification is preferable. When the composite resin is not obtained as the organic solvent solution in step 3, the composite resin may be dissolved in the organic solvent to obtain the composite resin solution before the phase inversion emulsification.
In the phase inversion emulsification method, it is preferable to add a basic compound to a solution in which the composite resin is dissolved in an organic solvent for neutralization.

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; acetic acid ester solvents such as ethyl acetate and isopropyl acetate. Solvents: Examples include alkyl halide solvents such as dichloromethane and chloroform. Among these, at least one selected from a ketone solvent and an acetic acid ester solvent is preferable, and methyl ethyl ketone, ethyl acetate and acetic acid are more preferable, from the viewpoint of easy removal from the mixed liquid after addition of the aqueous medium. At least one selected from isopropyl, more preferably methyl ethyl ketone.

The mass ratio of the organic solvent to the resin in the resin particles (organic solvent/resin) is preferably 0 from the viewpoint of dissolving the resin to facilitate phase inversion into the aqueous medium and from the viewpoint of improving the dispersion stability of the resin particles. 0.3 or more, more preferably 0.5 or more, still more preferably 0.7 or more, and preferably 5.0 or less, more preferably 3.0 or less, further preferably 2.0 or less, further preferably It is 1.5 or less.

Examples of the basic compound in step 4 include hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide, ammonia, trimethylamine, ethylamine, diethylamine, triethylamine, diethanolamine, triethanolamine and tributylamine. Examples include nitrogen basic substances. Among these, sodium hydroxide or ammonia is preferable from the viewpoint of improving the dispersion stability of the resin particles.
The equivalent amount (mol %) of the basic compound used with respect to the acid group of the resin is preferably 10 mol% or more, more preferably 50 mol% or more, and preferably from the viewpoint of improving the dispersion stability of the resin particles. Is 150 mol% or less, more preferably 120 mol% or less, still more preferably 100 mol% or less.
The equivalent amount (mol %) of the neutralizing agent can be calculated by the following formula. The use amount of the neutralizing agent is synonymous with the degree of neutralization when it is 100 mol% or less, and when the use amount of the neutralizing agent is more than 100 mol% in the following formula, the neutralizing agent is an acid group of the resin. Is excessive, and the degree of neutralization of the resin at this time is considered to be 100 mol %.
Equivalent amount of the neutralizing agent (mol %)=[{added mass of neutralizing agent (g)/equivalent amount of neutralizing agent}/[{acid value of resin (mgKOH/g)×mass of resin (g)}/ (56 x 1000)]] x 100

The water-based medium of step 4 is preferably one containing water as a main component, and the content of water in the water-based medium is preferably from the viewpoint of improving the dispersion stability of the resin particle dispersion and the viewpoint of reducing the environmental load. It is 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, further preferably 100% by mass. As water, deionized water, ion-exchanged water, and distilled water are preferably used.
As a component other than water, an organic solvent soluble 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; a cyclic ether such as tetrahydrofuran.

In step 4, the amount of the aqueous medium added is preferably 100 parts by mass or more, more preferably 150 parts by mass or more, and further preferably 200 parts by mass with respect to 100 parts by mass of the resin from the viewpoint of improving the dispersion stability of the resin particles. The amount is not less than 100 parts by mass, and preferably not more than 900 parts by mass, more preferably not more than 500 parts by mass, further preferably not more than 300 parts by mass.
The mass ratio of the aqueous medium to the organic solvent (aqueous medium/organic solvent) after the total amount is added is preferably 40/60 or more, more preferably 50/50 or more, still more preferably 60/40 or more, and preferably Is 90/10 or less, more preferably 85/15 or less, still more preferably 80/20 or less.

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 resin particles. Or less, more preferably 65° C. or less, still more preferably 50° C. or less.
From the viewpoint of improving the dispersion stability of the resin particles, the addition rate of the aqueous medium is preferably 0.5 parts by mass/min or more, more preferably 1 part by mass with respect to 100 parts by mass of the resin until the phase inversion is completed. Mass part/min or more, more preferably 3 mass part/min or more, and preferably 50 mass part/min or less, more preferably 30 mass part/min or less, still more preferably 20 mass part/min or less. .. There is no limitation on the addition rate of the aqueous medium after the phase inversion.

After the phase inversion emulsification, it may have a step of removing the organic solvent from the aqueous dispersion obtained by the phase inversion emulsification, if necessary.
The method for removing the organic solvent is not particularly limited, and any method can be used, but it is preferably distilled because it is dissolved in water. Further, the organic solvent may not be completely removed and may remain in the aqueous dispersion. In this case, the residual amount of the organic solvent in the aqueous dispersion is preferably 1% by mass or less, more preferably 0.5% by mass or less, and further preferably substantially 0%.

The solid content concentration of the obtained aqueous dispersion of resin particles is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 25% by mass or more, from the viewpoint of improving the productivity of the ink. , Preferably 50% by mass or less, more preferably 45% by mass or less, further preferably 40% by mass or less.
The solid content is the total amount of non-volatile components such as the above-mentioned optional components such as a resin, a surfactant that can be added if necessary, and a colorant.

The volume average particle diameter (D _V ) of the resin particles in the aqueous dispersion is preferably 20 nm or more from the viewpoint of improving dispersion stability in the ink and the aqueous medium, and improving the ejection property of the ink. It is more preferably 50 nm or more, still more preferably 70 nm or more, further preferably 80 nm or more, and preferably 1000 nm or less, more preferably 500 nm or less, further preferably 400 nm or less, further preferably 300 nm or less. The volume average particle diameter (D _V ) is measured by a dynamic light scattering method and is determined by the method described in the examples.

<Step 5>
In step 5, the aqueous dispersion of resin particles obtained in step 4 is mixed with a colorant (preferably polymer particles containing the colorant). In addition, various organic solvents, penetrants, dispersants, surfactants, viscosity modifiers, defoamers, preservatives, antifungal agents, rust preventives, pH adjusters, antioxidants, ultraviolet absorbers, etc. Additives may be added.
The aqueous ink of the present invention can be obtained through the above steps 1 to 5.

[Inkjet recording method]
The water-based ink of the present invention can be used as an ink for inkjet recording. As a preferred embodiment of using the water-based ink of the present invention in an inkjet recording method, after the water-based ink of the present invention is attached to a resin recording medium by an ink jet recording method, a resin recording medium to which the water-based ink is attached is used. Heat to 40° C. or higher and 100° C. or lower. The resin constituting the resin particles in the water-based ink diffuses on the printing surface of the resin-made recording medium and can act as a fixing aid for the colorant when forming a coating film, and adheres to the resin-made recording medium. The property can be further improved.

The water-based ink of the present invention can be used for both office printing and commercial and industrial printing of catalogs, leaflets, packages, labels and the like. Suitable for non-water-absorbing or low-water-absorbing resin recording media such as PET (polyethylene terephthalate), PVC (polyvinyl chloride), PP (polypropylene), NY (nylon), which are suitable for commercial and industrial label printing. Since it can be used, it is suitable for use in commercial or industrial printing.
In the present invention, “non-water-absorbing or low water-absorbing” means that the water absorption amount of the recording medium at a contact time of 100 msec between the recording medium and water is 0 g/m ² or more and 10 g/m ² or less. To do.

The resin recording medium is preferably at least one selected from polyethylene terephthalate film, polyvinyl chloride film, polypropylene film and nylon film, and more preferably at least one selected from polyethylene terephthalate film and nylon film. The resin recording medium may use a corona-treated base material.
Examples of commonly available films include Lumirror T60 (Toray Industries, Inc., polyethylene terephthalate), PVC80BP (Lintec Co., vinyl chloride), DGS-210WH (Roland DG Co., vinyl chloride), transparent PVC RE-137 (Vinyl chloride manufactured by Mimaki Engineering Co., Ltd.), Kainus KEE70CA (polyethylene manufactured by Lintec Co., Ltd.), YUPO SG90 PAT1 (polypropylene manufactured by Lintec Co., Ltd.), FOR, FOA (all manufactured by Futamura Chemical Co., Ltd., Polypropylene), Bonile RX (Kohjin Film & Chemicals Co., Ltd., nylon), Emblem ONBC (Unitika Co., Ltd., nylon) and the like.

The inkjet recording method of the present invention can use a known inkjet recording device. Examples of the inkjet recording device include a thermal inkjet recording device and a piezo inkjet recording device. The water-based ink of the present invention is more preferably used as a piezo type water-based ink for inkjet recording.
The heating temperature of the resin recording medium is preferably 50° C. or higher, more preferably 60° C. or higher, and preferably 90° C. or lower, more preferably from the viewpoint of obtaining excellent adhesion to various resin recording media. It is below 85°C.

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 methods.

[Acid value and hydroxyl value of polyester and composite resin]
It was 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 Corp.), a load of 1.96 MPa was applied by a plunger while heating 1 g of the sample at a heating rate of 6°C/min, 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 the sample flowed out was taken as the softening point.

[Glass transition temperature of polyester and composite resin]
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 cooled from that temperature. The sample for measurement was prepared by cooling to 0° C. at a speed of 10° C./min. Then, the temperature was raised at a temperature rising rate of 10° C./min, and the amount of heat was measured. Of the observed endothermic peaks, the peak temperature with the maximum peak area is taken as the maximum endothermic peak temperature, the extension line of the baseline below the maximum endothermic peak temperature, and the maximum slope from the rising part of the peak to the peak apex. The temperature at the intersection with the tangent line indicating is the glass transition temperature.

[Volume Average Particle Diameter (D _V ) of 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. The dispersion liquid diluted with water so that the concentration of the particles to be measured was about 5×10 ⁻³ mass% was put in a measurement cell, the temperature was 25° C., the angle between the incident light and the detector was 90°, and the number of integration was 100 times. The refractive index of water (1.333) was input as the refractive index of the dispersion solvent for measurement.

[Solid content of polyurethane solution and composite resin solution]
Using an infrared moisture meter "FD-230" (manufactured by Ketsuto Scientific Research Institute Co., Ltd.), a measurement sample of 5 g was dried at a temperature of 100° C. and a measurement mode of 96 (monitoring time 2.5 minutes/variation range 0.05%). And dried to measure the amount of solvent (% by mass) in the solution. The solid content concentration was calculated according to the following formula.
Solid content concentration (mass %)=100-solvent amount (mass %)

[Solid content of aqueous dispersion of resin particles]
Using an infrared moisture meter "FD-230" (manufactured by Ketsuto Scientific Research Institute Co., Ltd.), 5 g of a measurement sample is dried at a temperature of 150° C. and measurement mode 96 (monitoring time 2.5 minutes/variation range 0.05%). And the water content (mass %) of the aqueous dispersion was measured. The solid content concentration was calculated according to the following formula.
Solid content concentration (mass %)=100−water content (mass %)

[Number average molecular weight of polyester and composite resin]
The number average molecular weight was calculated by measuring the molecular weight distribution by gel permeation chromatography by the following method.
(1) Preparation of sample solution The sample was dissolved in chloroform so that the concentration was 0.5 g/100 ml. Then, this solution was filtered using a fluororesin filter “FP-200” (manufactured by Sumitomo Electric Industries, Ltd.) having a pore size of 2 μm to remove insoluble components to obtain a sample solution.
(2) Measurement of molecular weight distribution Tetrahydrofuran was caused to flow as a solution at a flow rate of 1 ml/min, and the column was stabilized in a constant temperature bath at 40°C. The measurement was performed by injecting 100 μl of the sample solution therein. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. In the calibration curve at this time, several types of monodisperse polystyrene (2.63×10 ³ , 2.06×10 ⁴ , 1.02×10 ⁵ manufactured by Tosoh Corporation, 2.10× manufactured by GL Sciences Inc.) were used. 10 ³ , 7.00×10 ³ , 5.04×10 ⁴ ) prepared as a standard sample was used.
Measuring device: CO-8010 (manufactured by Tosoh Corporation)
Analytical column: GMHLX+G3000HXL (manufactured by Tosoh Corporation)

[Weight average molecular weight of water-insoluble polymer (anionic polymer)]
Using the following measuring device and analytical column, gel permeation chromatography using N,N-dimethylformamide in which phosphoric acid and lithium bromide were dissolved at concentrations of 60 mmol/L and 50 mmol/L, respectively, as an eluent. It was measured by the method. The molecular weight (Mw, Mn) of the sample is several kinds of monodisperse polystyrene (product name: "TSKgel standard polystyrene"; type name: "A-500", "A-2500", "F-1", "F-10". “; all manufactured by Tosoh Corporation” was used 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 Concentration of Aqueous Dispersion of Polymer Particles Containing Colorant (Pigment-Containing Anionic Polymer Particles)]
Into a 30 mL polypropylene container (inner diameter: 40 mm, height: 30 mm), weigh out 10.0 g of sodium sulfate that has been constant weighted in a desiccator, add about 1.0 g of the sample, mix, and then weigh accurately. The temperature was maintained at 105° C. for 2 hours to remove volatile matter, and the mass was measured by leaving it in a desiccator for 15 minutes. 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]
Inkjet printer "IPSiO GX 2500" (manufactured by Ricoh Co., Ltd., piezo type) is filled with a water-based ink, and biaxially stretched PET film "Lumirror 75T60" (manufactured by Toray Industries, Inc.) and biaxially stretched corona-treated nylon film "Emblem ONBC". "(Unitika Ltd.)" was printed with an A4 solid image. A sample was prepared by drying for 10 minutes in a dryer at 80° C., and then allowing it to stand for 1 day in an environment room at room temperature of 25° C. and relative humidity of 50%. After that, a tape "Cellotape CT15" (registered trademark) (manufactured by Nichiban Co., Ltd.) having a length of 4 cm was attached to the printed surface of the sample, the tape was peeled off at an angle of 90° at a speed of 10 cm/sec, and the coated surface of the sample was removed. The remaining area was visually evaluated in the following 5 grades. The higher the score, the better the adhesion to various films.
<Evaluation criteria>
No peeling or peeling, but peeling area less than 5%: 5 points Peeling area 5% to less than 25%: 4 points Peeling area 25% to less than 50%: 3 points Peeling area 50% to less than 75%: 2 points Area 75% or more: 1 point

[Evaluation of scratch resistance]
An inkjet printer "IPSiO GX 2500" (manufactured by Ricoh Co., Ltd., piezo system) was filled with a water-based ink, and an A4 solid image was printed on a biaxially stretched corona-treated nylon film "Emblem ONBC" (manufactured by Unitika Ltd.). A sample was prepared by drying for 10 minutes in a dryer at 80° C., and then allowing it to stand for 1 day in an environment room at room temperature of 25° C. and relative humidity of 50%. Using the Gakushin-type friction tester "RT-300" (manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.), the coated surface of the sample was 500 g load/100 times with plain paper "XEROX 4200DP" (Fuji Xerox Co., Ltd.). After rubbing, the state of the coated surface was visually evaluated in the following 5 grades. The higher the score, the more excellent the scratch resistance.
<Evaluation criteria>
No scratches and peeling: 5 points Part of the coated surface has scratches: 4 points There are scratches on the entire coated surface: 3 points There are scratches on the entire coated surface and some peeling: 2 points There is peeling on the entire coated surface: 1 point

[Evaluation of alcohol resistance]
An inkjet printer "IPSiO GX GX 2500" (manufactured by Ricoh Co., Ltd., piezo type) was filled with an aqueous ink, and an A4 solid image was printed on a biaxially stretched PET film "Lumirror 75T60" (manufactured by Toray Industries, Inc.). A sample was prepared by drying for 10 minutes in a dryer at 80° C., and then allowing it to stand for 1 day in an environment room at room temperature of 25° C. and relative humidity of 50%. Then, with a cotton swab impregnated with an aqueous solution of ethanol whose concentration was adjusted to 0 to 100% by mass every 10% by mass, while keeping the load on the coated surface of the sample as little as possible, the width of 2 to 3 cm was reduced to 1 per second. At the reciprocating speed, the coated surface was rubbed 10 times back and forth. The state of the coated surface was visually evaluated, and the highest ethanol concentration at which no change such as scratches, peeling, or cloudiness was observed on the coated surface 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 S1 (Production of Polyester PES1)
The interior 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 was obtained. 2125 g of fumaric acid, 4 g of 4-tert-butylcatechol, and 40 g of tin di(2-ethylhexanoate) were added, and the temperature was raised to 210° C. over 5 hours while stirring under a nitrogen atmosphere, and the temperature was 210° C. for 2 hours. After holding, the reaction was carried out at 8.3 kPa until the desired softening point was reached to obtain polyester PES1. The characteristics of the polyester PES1 are shown in Table 1.

Production Example S2 (Production of Polyester PES2)
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 1,2-propanediol 2888 g, terephthalic acid 4416 g, fumaric acid 1102 g, and 4-tert-butylcatechol 2 g were used. , And 40 g of di(2-ethylhexanoic acid) tin were added, and the temperature was raised to 180° C. with stirring under a nitrogen atmosphere. Then, it heated up to 210 degreeC over 5 hours, and hold|maintained at 210 degreeC for 2 hours. Then, the reaction was carried out at 220° C. until the desired softening point was reached to obtain polyester PES2. The characteristics of the polyester PES2 are shown in Table 1.

Production Example S3 (Production of Polyester PES3)
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 5600 g of polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane was obtained. 1594 g of terephthalic acid, 369 g of trimellitic anhydride, and 40 g of di(2-ethylhexanoic acid) tin were added, the temperature was raised to 230° C. with stirring under a nitrogen atmosphere, and the temperature was maintained at 230° C. for 6 hours, and then the flask was used. The internal pressure was reduced and the pressure was maintained at 8.3 kPa for 1 hour. Then, after cooling to 210° C. and returning to atmospheric pressure, 557 g of fumaric acid and 2 g of 4-tert-butylcatechol were added, and after holding at 210° C. for 5 hours, the pressure in the flask was lowered to 8.3 kPa. The reaction was carried out until the desired softening point was reached to obtain polyester PES3. The characteristics of the polyester PES3 are shown in Table 1.

Production Example S4 (Production of Polyester PES4)
The interior of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane 5250 g, 1494 g of terephthalic acid, 1197 g of dodecenyl succinic anhydride and 40 g of di(2-ethylhexanoic acid) tin were added, the temperature was raised to 230° C. with stirring under a nitrogen atmosphere, and the temperature was maintained at 230° C. for 7 hours, and then in the flask. The pressure was reduced and the pressure was maintained at 8.3 kPa for 1 hour. Then, after cooling to 215° C. and returning to atmospheric pressure, 346 g of trimellitic anhydride was added, and after holding at 215° C. for 2 hours, the pressure in the flask was lowered to reach a desired softening point at 8.3 kPa. The reaction was continued until it reached to obtain polyester PES4. The characteristics of the polyester PES4 are shown in Table 1.

Production Example S5 (Production of Polyester PES5)
The interior of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane 5250 g, 1270 g of terephthalic acid, 1556 g of dodecenylsuccinic anhydride, and 40 g of di(2-ethylhexanoic acid) tin were added, the temperature was raised to 230° C. with stirring under a nitrogen atmosphere, and the temperature was maintained at 230° C. for 6 hours, and then in the flask. The pressure was reduced and the pressure was maintained at 8.3 kPa for 1 hour. Then, after cooling to 215° C. and returning to atmospheric pressure, 288 g of trimellitic anhydride was added, and after holding at 215° C. for 1 hour, the pressure in the flask was lowered to reach the desired softening point at 8.3 kPa. The reaction was continued until it reached to obtain polyester PES5. The characteristics of the polyester PES5 are shown in Table 1.

[Manufacture of polyurethane]
Production Example U1 (Production of polyurethane PU1)
In a four-necked flask equipped with a nitrogen introduction tube, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Scientific Co., Ltd.) and a thermocouple, 150 g of methyl ethyl ketone and polytetramethylene glycol "polytetramethylene oxide 1,000". (Manufactured by Wako Pure Chemical Industries, Ltd., weight average molecular weight 1,000) 100 g, 2,2-bis(hydroxymethyl)butyric acid 9.7 g, and di(2-ethylhexanoic acid)tin 0.5 g as a catalyst, The mixture was stirred at room temperature (25° C.) under a nitrogen atmosphere and mixed. Next, 36.7 g of isophorone diisocyanate was added, the temperature was raised to 80° C. with stirring, the reaction was carried out for 5 hours while maintaining 80° C., and the heating was terminated to obtain polyurethane PU1 having an isocyanate group. After cooling to room temperature, methyl ethyl ketone was added to adjust the solid content concentration to 50 mass% to obtain a 50 mass% solution of polyurethane PU1 in methyl ethyl ketone (SPU1).

Production Example U2 (Production of polyurethane PU2)
In a four-necked flask equipped with a nitrogen introduction tube, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Scientific Co., Ltd.) and a thermocouple, 150 g of methyl ethyl ketone and polytetramethylene glycol "polytetramethylene oxide 1,000". (Manufactured by Wako Pure Chemical Industries, Ltd., weight average molecular weight 1,000) 100 g, 2,2-bis(hydroxymethyl)butyric acid 9.0 g, and di(2-ethylhexanoic acid)tin 0.5 g as a catalyst, The mixture was stirred at room temperature (25°C) under a nitrogen atmosphere and mixed. Next, 27.0 g of hexamethylene diisocyanate was added, the temperature was raised to 80° C. with stirring, the reaction was carried out for 5 hours while maintaining 80° C., and the heating was terminated to obtain polyurethane PU2 having an isocyanate group. After cooling to room temperature, methyl ethyl ketone was added to adjust the solid content concentration to 50 mass% to obtain a 50 mass% methyl PU solution of polyurethane PU2 (SPU2).

Production Example U3 (production of polyurethane PU3)
In a four-necked flask equipped with a nitrogen introduction tube, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Scientific Co., Ltd.) and a thermocouple, 170 g of methyl ethyl ketone and polytetramethylene glycol "polytetramethylene oxide 1,000" (Manufactured by Wako Pure Chemical Industries, Ltd., weight average molecular weight 1,000) 100 g, 2,2-bis(hydroxymethyl)butyric acid 10.2 g, and di(2-ethylhexanoic acid)tin 0.5 g as a catalyst, The mixture was stirred at room temperature (25°C) under a nitrogen atmosphere and mixed. Next, 44.3 g of dicyclohexylmethane diisocyanate was added, the temperature was raised to 80° C. with stirring, the reaction was carried out for 5 hours while maintaining 80° C., and the heating was terminated to obtain polyurethane PU3 having an isocyanate group. After cooling to room temperature, methyl ethyl ketone was added to adjust the solid content concentration to 50 mass% to obtain a 50 mass% methyl PU solution of polyurethane PU3 (SPU3).

Production Example U4 (Production of polyurethane PU4)
In a four-necked flask equipped with a nitrogen inlet tube, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Scientific Co., Ltd.) and a thermocouple, 170 g of methyl ethyl ketone and polytetramethylene glycol "polytetramethylene oxide 650" ( Wako Pure Chemical Industries, Ltd., weight average molecular weight 650) 100g, 2,2-bis(hydroxymethyl)butyric acid 10.6g, di(2-ethylhexanoic acid) tin 0.5g as a catalyst, room temperature (25 ℃ ), and mixed with stirring under a nitrogen atmosphere. Next, 50.1 g of isophorone diisocyanate was added, and the temperature was raised to 80° C. while stirring. The reaction was carried out for 5 hours while maintaining the temperature at 80° C., and heating was terminated to obtain polyurethane PU4 having an isocyanate group. After cooling to room temperature, methyl ethyl ketone was added to adjust the solid content concentration to 50 mass% to obtain a 50 mass% methyl PU solution of polyurethane PU4 (SPU4).

Production Example U5 (Production of polyurethane PU5)
In a four-necked flask equipped with a nitrogen introduction tube, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Scientific Co., Ltd.) and a thermocouple, 150 g of methyl ethyl ketone, polytetramethylene glycol "polytetramethylene oxide 1,400". (Manufactured by Wako Pure Chemical Industries, Ltd., weight average molecular weight 1,400) 100 g, 2,2-bis(hydroxymethyl)butyric acid 9.2 g, and di(2-ethylhexanoic acid)tin 0.5 g as a catalyst, The mixture was stirred at room temperature (25° C.) under a nitrogen atmosphere and mixed. Next, 29.6 g of isophorone diisocyanate was added, and the temperature was raised to 80° C. while stirring. The reaction was carried out for 5 hours while maintaining the temperature at 80° C., and the heating was terminated to obtain polyurethane PU5 having an isocyanate group. After cooling to room temperature, methyl ethyl ketone was added to adjust the solid content concentration to 50% by mass to obtain a 50% by mass methyl ethyl ketone solution (SPU5) of polyurethane PU5.

Production Example R1 (Production of Composite Resin 1)
A four-necked flask equipped with a nitrogen introduction tube, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Scientific Co., Ltd.) and a thermocouple was charged with a solution prepared by mixing 100 g of polyester PES and 100 g of methyl ethyl ketone. Further, 200 g of a 50 mass% methyl ethyl ketone solution (SPU1) of polyurethane PU1 having an isocyanate group was added, and the mixture was stirred at room temperature (25° C.) under a nitrogen atmosphere and mixed. Next, while stirring, the temperature was raised to 80° C., and the temperature was maintained at 80° C. for 2 hours to obtain a polyurethane-bonded polyester (composite resin 1). After cooling to room temperature, methyl ethyl ketone was added to adjust the solid content concentration to 50 mass% to obtain a composite resin 1 solution (50 mass% methyl ethyl ketone solution). The characteristics of the composite resin 1 in the composite resin 1 solution are shown in Table 2. In addition, in measuring each characteristic of the composite resin by the above-mentioned method, a part of the solution was sampled and dried to collect the composite resin 1 and used for the measurement.

Production Example R2 (Production of Composite Resin 2)
A four-necked flask equipped with a nitrogen inlet tube, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Scientific Co., Ltd.) and a thermocouple was charged with a solution prepared by mixing 1140 g of polyester PES and 140 g of methyl ethyl ketone. Furthermore, 120 g of a 50 mass% methyl ethyl ketone solution (SPU1) of polyurethane PU1 having an isocyanate group was added, and the mixture was stirred and mixed at room temperature (25° C.) under a nitrogen atmosphere. Next, with stirring, the temperature was raised to 80° C., and the temperature was maintained at 80° C. for 2 hours to obtain a polyurethane-bonded polyester (composite resin 2). After cooling to room temperature, methyl ethyl ketone was added to adjust the solid content concentration to 50 mass% to obtain a composite resin 2 solution (50 mass% methyl ethyl ketone solution). The characteristics of the composite resin 2 in the composite resin 2 solution are shown in Table 2.

Production Example R3 (Production of Composite Resin 3)
A four-necked flask equipped with a nitrogen inlet tube, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Scientific Co., Ltd.) and a thermocouple was charged with a solution prepared by mixing 1180 g of polyester PES and 180 g of methyl ethyl ketone, Furthermore, 40 g of a 50 mass% methyl ethyl ketone solution (SPU1) of polyurethane PU1 having an isocyanate group was added, and the mixture was stirred and mixed at room temperature (25° C.) under a nitrogen atmosphere. Next, with stirring, the temperature was raised to 80° C., and the temperature was maintained at 80° C. for 2 hours to obtain a polyurethane-bonded polyester (composite resin 3). After cooling to room temperature, methyl ethyl ketone was added to adjust the solid content concentration to 50 mass% to obtain a composite resin 3 solution (50 mass% methyl ethyl ketone solution). The characteristics of the composite resin 3 in the composite resin 3 solution are shown in Table 2.

Production Examples R4 to R14 (Production of Composite Resins 4 to 14)
In the production of the composite resin 1, solutions of the composite resins 4 to 14 were obtained in the same manner except that polyester and polyurethane shown in Table 2 were used. The properties of the composite resin in the composite resin solution are shown in Table 2.

Various abbreviations in the table have the following meanings.
IPDI: Isophorone diisocyanate
HMDI: Hexamethylene diisocyanate
DCI: dicyclohexylmethane diisocyanate
PTMG: Polytetramethylene glycol

Production Examples E1 to E8, E11 to E16 (Production of Aqueous Dispersions E1 to E8 and E11 to E16 of Resin Particles)
A four-necked flask equipped with a nitrogen inlet tube, a reflux condenser, a stirrer "Three One Motor BL300" (manufactured by Shinto Scientific Co., Ltd.) and a thermocouple was charged with the composite resin solution of the type shown in Table 3, and then the table. The amount of 5 mass% sodium hydroxide aqueous solution shown in 3 was added and stirred for 30 minutes to obtain an organic solvent-based slurry. Deionized water was added dropwise at a rate of 20 mL/min under stirring at 30° C., the temperature was raised to 60° C., and then methyl ethyl ketone was distilled off while gradually reducing the pressure to 80 kPa to 30 kPa. Was removed. After cooling to 25° C., the mixture was filtered through a 150-mesh wire net and the solid content concentration was adjusted to 30% by mass with deionized water to obtain an aqueous dispersion of resin particles.
Table 3 shows the volume average particle diameter (D _v ) of the resin particles in the aqueous dispersion of the obtained resin particles.

Production Examples E9 to E10 (Production of Aqueous Dispersion of Resin Particles E9 to E10)
An aqueous dispersion of resin particles was obtained in the same manner as in Production Example E1 above, except that the type of resin solution shown in Table 3 was used instead of the composite resin solution. Table 3 shows the volume average particle diameter (D _v ) of the resin particles in the aqueous dispersion of the obtained resin particles.

Production Example C1 (Preparation of Aqueous Dispersion C1 of Water-Insoluble Polymer Particles Containing 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.), methoxy polyethylene glycol methacrylate "M-230G" (new Nakamura Chemical Co., Ltd., average addition mole number of oxyethylene group: 23) 140 g, styrene macromonomer "AS-6S" (Toagosei Co., Ltd., solid content: 50%) 140 g were mixed, and a monomer mixture liquid ( 770 g) was prepared. 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 above-mentioned monomer mixture liquid were put in a reaction vessel and mixed, and nitrogen gas substitution was carried out.
On the other hand, in a dropping funnel, 80% by mass (616 g) of the monomer mixture liquid, 2.45 g of the polymerization chain transfer agent, 173.25 g of methyl ethyl ketone and the polymerization initiator 2,2′-azobis(2,4-dimethylvaleronitrile). (Product name: "V-65", manufactured by Wako Pure Chemical Industries, Ltd.) A mixture of 5.6 g was put, and the mixed solution in the reaction vessel was heated to 75° C. under a nitrogen atmosphere while stirring and added dropwise. The mixed solution in the funnel was added dropwise over 4.5 hours. Thereafter, a mixture of the remaining 10% by mass (77 g) of the monomer mixed liquid, 0.7 g of the polymerization chain transfer agent, 126 g of methyl ethyl ketone and 1.4 g of the polymerization initiator was added as a second stage dropping at 75° C. and 1.7. It dripped over time.
After the dropping was completed, 2.1 g of the initiator was mixed, the temperature was raised to 80° C., and the mixture was stirred for 1.5 hours. A polymer solution (weight average molecular weight of polymer: 26,000) was obtained by repeating the operation of mixing the initiator, raising the temperature, and stirring the mixture twice more.
(2) Production of Aqueous Dispersion of Polymer Particles Containing Pigment (Anionic Polymer Particles Containing Pigment) Obtained by drying under reduced pressure the polymer solution obtained in the synthesis of the water-insoluble polymer (anionic polymer) in (1) above. 20 g of the obtained polymer is dissolved in 62.8 g of methyl ethyl ketone, and 5.01 g of a 5N sodium hydroxide aqueous solution, 1.13 g of 25 mass% ammonia water, and 236.5 g of ion-exchanged water are added thereto, and the temperature is 10 to 15°C. Then, the mixture was stirred and mixed at 2,000 r/min for 15 minutes using a disper blade.
Subsequently, 45 g of magenta pigment: PV19 (product name: “Inkjet Magenta E5B02”, manufactured by Clariant Japan Co., Ltd.) and 25 g of magenta pigment: PR122 (product name: “6111T”, manufactured by Dainichiseika Kogyo Co., Ltd.) were added, and 10 were added. The mixture was stirred and mixed for 3 hours at 7,000 r/min using a Disper blade at -15°C. The obtained dispersion liquid was filtered with 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, and 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 preservative "Proxel XL2" (manufactured by Avicia) and 19.8 g of ion-exchanged water, sterilized at 70°C for 1 hour, and then cooled to 25°C. , An aqueous dispersion C1 (solid content concentration: 20% by mass, volume average particle diameter (D _V ): 133 nm) of polymer particles containing a pigment (pigment-containing anionic polymer particles) by filtering with a filter having a pore size of 5 μm ) Got.

Examples 1-14 and Comparative Examples 1-2 (Production of water-based inks 1-14, 51-52)
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" ( Olfine is a registered trademark) (active ingredient: acetylene glycol-based surfactant, manufactured by Nisshin Chemical Industry Co., Ltd.) 1.0 part by mass, and deionized water 26.6 parts by mass are mixed, and a magnetic stirrer is used. The mixture was stirred at room temperature (25°C) 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 obtained in Production Example C1 (4.0 parts by mass in terms of pigment (in 100 parts by mass of the water-based ink)) was stirred with a magnetic stirrer. While mixing the entire amount of the mixed solution, 16.7 parts by mass of an aqueous dispersion of resin particles shown in Table 4 (5.0 parts by mass in terms of solid content (in 100 parts by mass of the water-based ink)) was added dropwise with a dropper. While stirring and mixing. Finally, filtration was performed with a filter "Minisart" (registered trademark) (manufactured by Sartorius Stedim Biotech) having a pore size of 1.2 µm to obtain an aqueous ink. The evaluation results of the obtained water-based ink are shown in Tables 4 and 5. The evaluation of alcohol resistance was conducted only for Example 1 and Examples 9-14.

Comparative Example 3 (Production of water-based ink 53)
16.7 parts by mass of an aqueous dispersion of resin particles (5.0 parts by mass in terms of solid content (in 100 parts by mass of the water-based ink)), 8.35 parts by mass of an aqueous dispersion E9 of resin particles 9 and an aqueous solution of the resin particles 10. Aqueous ink 53 was obtained in the same manner as in Example 1 except that 8.35 parts by mass of Dispersion E10 (5.0 parts by mass in terms of total solid content (in 100 parts by mass of aqueous ink)) was used. Table 4 shows the evaluation results of the obtained water-based ink. The evaluation of alcohol resistance was conducted only for Example 1 and Examples 9-14.

As described above, by comparing the water-based ink of the example with the water-based ink of the comparative example, it can be understood that the water-based ink has excellent adhesion to PET, nylon, and abrasion resistance.
On the other hand, from the results in Table 5, the water-based ink of Example 1 had sufficient durability with respect to water (alcohol concentration 0%), but the 10% by mass ethanol aqueous solution had an effect on the coated surface. Was given. On the other hand, when a polyvalent carboxylic acid having a valence of 3 or more is used as the constituent unit of the polyester segment, the film covering the printed image has a branched/crosslinked structure, which reduces the affinity with alcohol, It can be seen that the alcohol resistance is improved.

Claims (6)

Step 1: a step of polycondensing an alcohol component and a carboxylic acid component to obtain a polyester,
Step 2: a step of reacting a polyol compound containing a polyether polyol with a polyisocyanate compound to obtain polyurethane,
Step 3: A step of obtaining a composite resin from the polyester obtained in Step 1 and the polyurethane obtained in Step 2.
Step 4: a step of dispersing the composite resin obtained in Step 3 in an aqueous medium to obtain an aqueous dispersion of resin particles, and Step 5: combining the aqueous dispersion of resin particles obtained in Step 4 and a colorant. Has a step of mixing,
A method for producing an aqueous ink, wherein the mass ratio of polyester/polyurethane in step 3 is 40/60 or more and 95/5 or less,
The water-based ink contains a colorant and resin particles,
The resin particles contain a composite resin having a polyester segment and a polyurethane segment,
In the composite resin, the content of the polyester segment is 40 % by mass or more and 95% by mass or less, the content of the constitutional unit derived from the polyether polyol is 3% by mass or more and 50 % by mass or less, the content of the constitutional unit derived from the polyisocyanate compound. Is 2% by mass or more and 20% by mass or less,
In the composite resin, the content of the polyester segment [PES] (mass %), the content of the constituent unit derived from polyether polyol [PEP] (mass %), the content of the constituent unit derived from the polyisocyanate compound [PIS] ( mass percent) have a following relationship,
The alcohol component contains at least one selected from an alkylene oxide adduct of bisphenol A, hydrogenated bisphenol A, and an aliphatic diol having a hydroxy group bonded to a secondary carbon atom and having 3 to 6 carbon atoms,
The carboxylic acid component contains at least one selected from isophthalic acid, terephthalic acid, fumaric acid, adipic acid, sebacic acid, and dodecenylsuccinic acid,
The polyether polyol has an alkyleneoxy group having 2 to 8 carbon atoms, and has a weight average molecular weight (Mw) of 500 to 5,000.
The polyisocyanate compound contains an aliphatic diisocyanate,
The glass transition temperature of the composite resin is 25° C. or higher and 60° C. or lower,
The acid value of the composite resin is 10 mgKOH/g or more and 50 mgKOH/g or less,
The number average molecular weight of the composite resin is 1,000 or more and 10,000 or less,
A method for producing an aqueous ink, wherein the volume average particle diameter (D _V ) of the resin particles in the aqueous dispersion is 20 nm or more and 400 nm or less .
[PES]>[PEP]>[PIS] The water-based ink according to claim 1, wherein a molar ratio (OH/NCO) of the hydroxyl group of the polyol compound and the isocyanate group of the polyisocyanate compound in the raw material monomer of the polyurethane segment is 0.5 or more and 1.0 or less. Manufacturing method. Polyol compound of the raw material monomer of the polyurethane segments, further comprising a diol having a carboxy group, method for producing a water-based ink according to claim 1 or 2. The polyester segment is a polycondensate of alcohol component and the carboxylic acid component contains a trivalent or higher-valent carboxylic acid as the carboxylic acid component, the water-based ink according to any one of claims 1 to 3 Production method. The method for producing an aqueous ink according to claim 4 , further comprising, as the carboxylic acid component, succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms. Wherein the colorant is a polymer particles containing a colorant, method of manufacturing an aqueous ink according to any one of claims 1-5.