JP4449043B2 - Water-based polyurethane resin, water-based ink and pigment dispersion - Google Patents

Description

  The present invention relates to a water-based polyurethane resin, a water-based ink, and a pigment dispersion, and particularly relates to a water-based polyurethane resin suitable for a water-based ink and a pigment dispersion, and a water-based ink and a pigment dispersion using the water-based polyurethane resin.

Water-based polyurethane resins are widely used in various fields, and are known to be used for water-based inks, for example.
For example, a water-based polyurethane dispersant in which an anionic group is introduced into the isocyanate group via a urethane bond, using a polyisocyanate compound having an average number of functional groups of isocyanate groups in one molecule greater than 2, is used for an aqueous printing ink. Thus, it has been proposed to improve the dispersibility of the pigment and the storage stability of the aqueous pigment dispersion (see, for example, Patent Document 1).

  Further, for example, in an aqueous ink for ink jet recording containing an acid group-containing polyether polyurethane resin and a basic substance, the acid group-containing polyether polyurethane resin contains a poly (oxytetramethylene) structure and has an acid value. It has been proposed that a water-based ink for ink jet recording excellent in initial pigment dispersibility can be obtained by using a 40-90 polyether polyurethane resin (see, for example, Patent Document 2).

In addition, in an inkjet recording ink comprising a water-insoluble or poorly water-soluble colorant, a dispersant, and a water-soluble medium, a sulfone obtained by sulfonating an aromatic compound containing a polynuclear aromatic compound as the dispersant. It has been proposed that an ink for ink jet recording excellent in long-term storage stability and environmental stability can be obtained by using a polymer dispersant obtained by neutralizing a compound after formalin condensation (for example, (See Patent Document 3).
JP 2000-154227 A JP 2005-290044 A JP-A-10-298478

However, the inks described above have poor stability and poor dispersibility.
An object of the present invention is to provide a water-based ink excellent in dispersibility and stability, and further excellent in optical properties, a water-based ink dispersion used in the water-based ink, and a water-based polyurethane resin used in them. There is to do.

In order to achieve the above object, the aqueous polyurethane resin of the present invention comprises a fluorene skeleton-containing active hydrogen compound having a fluorene skeleton and an active hydrogen group, and a hydrophilic group-containing active hydrogen compound having a carboxyl group and an active hydrogen group. And a polyisocyanate component containing a polyisocyanate compound to obtain an aqueous dispersion having an acid value of 10 to 130 KOHmg / g, a pigment dispersant and / or a resin for aqueous ink It is used as a feature.
In the aqueous polyurethane resin of the present invention, it is preferable that the fluorene skeleton-containing active hydrogen compound is 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene.

In the aqueous polyurethane resin of the present invention, it is preferable that the polyisocyanate compound is an alicyclic diisocyanate.
Furthermore, the aqueous polyurethane resin of the present invention, the content of fluorene skeleton of fluorene skeleton-containing active hydrogen compound of the water polyurethane resin is suitably a 0.1 to 60 wt%.

When the aqueous polyurethane resin of the present invention is used as a pigment dispersant, the acid value is 50 to 130 KOH mg / g, and the content of the fluorene skeleton of the fluorene skeleton-containing active hydrogen compound in the aqueous polyurethane resin is 0.1 to 40% by weight is preferable.

  The present invention also includes an aqueous ink containing the above-described aqueous polyurethane resin and a pigment, and a pigment dispersion containing the above-described aqueous polyurethane resin and a pigment.

  The aqueous polyurethane resin of the present invention can impart excellent dispersibility and stability to the pigment, and can improve optical characteristics and physical properties of the coating film. Therefore, the aqueous ink or pigment dispersion containing the aqueous polyurethane resin of the present invention is excellent in dispersibility and stability, and can exhibit excellent optical properties and physical properties of the coating film.

The aqueous polyurethane resin of the present invention can be obtained by a reaction of an active hydrogen component containing a fluorene skeleton-containing active hydrogen compound, a hydrophilic group-containing active hydrogen compound, and a polyisocyanate component containing a polyisocyanate compound.
In the present invention, the fluorene skeleton-containing active hydrogen compound is a compound having a fluorene skeleton that can react with an isocyanate group, for example, an active hydrogen group such as a hydroxyl group or an amino group (hereinafter the same), A fluorene skeleton-containing active hydrogen compound having an active hydrogen group, preferably a fluorene skeleton-containing active hydrogen compound having two active hydrogen groups, and more preferably a fluorene skeleton-containing active hydrogen compound having two hydroxyl groups.

  As such a fluorene skeleton-containing active hydrogen compound, more specifically, for example, 9,9-bis (4- (hydroxyalkoxy) phenyl) fluorene represented by the following general formula (1), the following general formula 9,9-bis (4-hydroxyphenyl) fluorene represented by (2) (commercially available product, bisphenol fluorene: manufactured by Osaka Gas Chemical Co., Ltd.), 9,9-bis (4- Hydroxytoluyl) fluorene (commercially available product, biscresol fluorene: manufactured by Osaka Gas Chemical Co., Ltd.), 9,9-bis (hydroxyalkyl) fluorene represented by the following general formula (4), and the like.

(In general formula (1), R1 is the same or different and represents an alkylene group having 1 to 4 carbon atoms.)

(In general formula (2), R2 is the same or different and represents an alkylene group having 1 to 4 carbon atoms.)
In (1) or (4) above, examples of the alkylene group having 1 to 4 carbon atoms represented by R1 and R2 include methylene, ethylene, propylene, butylene and the like.
Examples of the 9,9-bis (4- (hydroxyalkoxy) phenyl) fluorene represented by the general formula (1) include 9,9-bis (4- (hydroxymethoxy) phenyl) fluorene, 9,9- Bis (4- (2-hydroxyethoxy) phenyl) fluorene (commercial product, bisphenoxyethanol fluorene: manufactured by Osaka Gas Chemical Company), 9,9-bis (4- (2-hydroxypropoxy) phenyl) fluorene, 9,9- Bis (4- (3-hydroxypropoxy) phenyl) fluorene, 9,9-bis (4- (4-hydroxybutoxy) phenyl) fluorene and the like can be mentioned.

  Examples of the 9,9-bis (hydroxyalkyl) fluorene represented by the general formula (4) include 9,9-bis (hydroxymethyl) fluorene, 9,9-bis (2-hydroxyethyl) fluorene, 9 , 9-bis (2-hydroxypropyl) fluorene, 9,9-bis (3-hydroxypropyl) fluorene, 9,9-bis (4-hydroxybutyl) fluorene, and the like.

These fluorene skeleton-containing active hydrogen compounds may be used alone or in combination of two or more, preferably 9,9-bis (4- (hydroxyalkoxy) phenyl) fluorene represented by the general formula (1), preferably 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene.
The fluorene skeleton-containing active hydrogen compound is, for example, 0.1 to 100 parts by weight, preferably 50 to 100 parts by weight with respect to 100 parts by weight of the active hydrogen component excluding the hydrophilic group-containing active hydrogen compound. Blended.

  The fluorene skeleton-containing active hydrogen compound is a fluorene skeleton of a fluorene skeleton-containing active hydrogen compound in an aqueous polyurethane resin (that is, a solid content of an aqueous dispersion of an aqueous polyurethane resin described later) (that is, fluorenylidene (a divalent group of fluorene). )) Content is 0.1 to 60% by weight, preferably 10 to 50% by weight. If the content of the fluorene skeleton-containing active hydrogen compound is less than the above range, the dispersion stability of the pigment and desired optical properties may not be obtained. Moreover, when more than said range, the fall of a coating-film physical property and the dispersibility of a pigment may be produced.

In the present invention, the hydrophilic group-containing active hydrogen compound is a compound having both a carboxyl group and an active hydrogen group, and includes, for example, a hydrophilic group having one carboxyl group and two or more active hydrogen groups. Active hydrogen compound, preferably a hydrophilic group-containing active hydrogen compound having one carboxyl group and having two active hydrogen groups, more preferably a hydrophilic group having one carboxyl group and having two hydroxyl groups Ru is like containing active hydrogen compound.

  More specifically, examples of the hydrophilic group-containing active hydrogen compound having a carboxyl group include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid, and 2,2-dimethylol. Examples include dihydroxycarboxylic acids such as butanoic acid, 2,2-dimethylolbutyric acid and 2,2-dimethylolvaleric acid, and diaminocarboxylic acids such as lysine and arginine.

Furthermore, as the hydrophilic group-containing active hydrogen compound, hydrophilic group-containing active hydrogen compound, it may be mentioned alkylene oxide-modified alkylene oxide such as ethylene oxide or propylene oxide is added.

These hydrophilic group-containing active hydrogen compounds may be used alone or in combination of two or more.
Moreover, a hydrophilic group containing active hydrogen compound is mix | blended in the ratio of 5-70 weight part with respect to 100 weight part of active hydrogen components, Preferably, it is 15-55 weight part.
The hydrophilic group-containing active hydrogen compound is blended so that the acid value of the aqueous polyurethane resin is 10 to 130 KOHmg / g, preferably 20 to 100 KOHmg / g. When the acid value is smaller than the above range, the water dispersibility and water solubility of the polymer may be lowered. On the other hand, if it is larger than the above range, the viscosity of the polymer aqueous dispersion may increase or the water resistance of the ink may decrease.

Moreover, in the water-based polyurethane resin of this invention, components other than the above can also be included as an active hydrogen component as needed. An example of such a component is a polyol compound.
The polyol compound is a compound having two or more hydroxyl groups, and examples thereof include a low molecular weight polyol and a high molecular weight polyol (hereinafter referred to as macropolyol).

  The low molecular weight polyol is, for example, a polyol compound having a number average molecular weight of 60 to 400, such as ethylene glycol, propanediol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1 , 6-hexanediol, neopentyl glycol, alkane (carbon number 7 to 22) diol, diethylene glycol, triethylene glycol, dipropylene glycol, cyclohexanedimethanol, alkane-1,2-diol (carbon number 17 to 20), hydrogen Low molecular weight diols such as bisphenol A, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octene-3,8-diol, bishydroxyethoxybenzene, xylene glycol, bishydroxyethylene terephthalate, etc. For example, glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, trimethylolpropane, 2,2-bis Low molecular weight triols such as (hydroxymethyl) -3-butanol and other aliphatic triols (8 to 24 carbon atoms), for example, 4 such as tetramethylolmethane, D-sorbitol, xylitol, D-mannitol, D-mannitol And low molecular weight polyols having one or more hydroxyl groups. These low molecular weight polyols can be used alone or in combination of two or more.

Examples of the macropolyol include polyether polyol, polycarbonate polyol, polyester polyol, acrylic polyol, epoxy polyol, natural oil polyol, silicone polyol, fluorine polyol, and polyolefin polyol.
As the polyether polyol, polyalkylene oxide, for example, polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol (obtained by addition reaction of alkylene oxide such as ethylene oxide and / or propylene oxide, using the above-described low molecular weight polyol as an initiator, Random or block copolymer). Examples thereof include polytetramethylene ether glycol obtained by ring-opening polymerization of tetrahydrofuran.

Examples of the polycarbonate polyol include polycarbonate diol obtained by ring-opening polymerization of carbonates such as ethylene carbonate and dimethyl carbonate using the above-described low molecular weight polyol as an initiator.
Examples of the polyester polyol include one or more of the above-described low molecular weight polyols and, for example, oxalic acid, malonic acid, succinic acid, methyl succinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3. -Dicarboxypropane, 3-methyl-3-ethylglutaric acid, azelaic acid, sebacic acid, other aliphatic dicarboxylic acids (11 to 13 carbon atoms), hydrogenated dimer acid, maleic acid, fumaric acid, itaconic acid, Carboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, toluene dicarboxylic acid, dimer acid and het acid, and acid anhydrides derived from these carboxylic acids such as oxalic anhydride, succinic anhydride, maleic anhydride Acid, phthalic anhydride, 2-alkyl anhydride (12 to 18 carbon atoms) succinic acid, tetrahydro anhydride Le acid, trimellitic anhydride, and further, an acid halide derived from such these carboxylic acids, such as oxalic acid dichloride, adipic acid dichloride, and polyester polyols obtained by reaction of such sebacic acid dichloride. Also, for example, lactone-based polyester polyols such as polycaprolactone polyols and polyvalerolactone polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-valerolactone using the low molecular weight polyol as an initiator. Etc.

  Examples of the acrylic polyol include a copolymer obtained by copolymerizing a polymerizable monomer having one or more hydroxyl groups in the molecule and another monomer copolymerizable therewith. . Examples of the polymerizable monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2,2-dihydroxymethylbutyl (meth) acrylate, and polyhydroxy. Examples thereof include alkyl maleates and polyhydroxyalkyl fumarate. Moreover, as another monomer copolymerizable with these, for example, (meth) acrylic acid, alkyl (meth) acrylate (1 to 12 carbon atoms), maleic acid, alkyl maleate, fumaric acid, fumaric acid Alkyl, itaconic acid, alkyl itaconate, styrene, α-methylstyrene, vinyl acetate, (meth) acrylonitrile, 3- (2-isocyanato-2-propyl) -α-methylstyrene, trimethylolpropane tri (meth) acrylate, Examples include pentaerythritol tetra (meth) acrylate. The acrylic polyol can be obtained by copolymerizing these monomers in the presence of a suitable solvent and a polymerization initiator.

Examples of the epoxy polyol include an epoxy polyol obtained by a reaction of the above-described low molecular weight polyol with a polyfunctional halohydrin such as epichlorohydrin or β-methylepichlorohydrin.
Examples of the natural oil polyol include hydroxyl group-containing natural oils such as castor oil and coconut oil.

As the silicone polyol, for example, in the copolymerization of the acrylic polyol described above, a vinyl group-containing silicone compound such as γ-methacryloxypropyltrimethoxysilane is used as another copolymerizable monomer. Examples include coalesced and terminal alcohol-modified polydimethylsiloxane.
As the fluorine polyol, for example, in the copolymerization of the acrylic polyol described above, a vinyl group-containing fluorine compound such as tetrafluoroethylene or chlorotrifluoroethylene is used as another copolymerizable monomer. Examples include coalescence.

  Examples of the polyolefin polyol include polybutadiene polyol, partially saponified ethylene-vinyl acetate copolymer, and the like. These macropolyols have a number average molecular weight of, for example, 500 to 5,000, preferably 1000 to 2,000, and a hydroxyl group equivalent of, for example, 20 to 300, preferably 50 to 120. These macropolyols can be used alone or in combination of two or more.

As the polyol compound, one kind or two or more kinds are appropriately selected from the above-described low molecular weight polyol and macropolyol. As a polyol compound, Preferably, a macropolyol, More preferably, a polyether polyol is mentioned.
Moreover, a polyol compound is mix | blended in the ratio of 1-20 weight part with respect to 100 weight part of active hydrogen components, Preferably, 5-10 weight part.

In the present invention, the polyisocyanate compound is a compound having two or more isocyanate groups, preferably a compound having two isocyanate groups, for example, an aliphatic polyisocyanate, an alicyclic polyisocyanate, an aromatic aliphatic polyisocyanate. Examples thereof include isocyanate and aromatic polyisocyanate.
Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI), trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 1,2-, 2,3- or 1,3-butylene diisocyanate, 2,4,4. -Or aliphatic diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate.

Examples of the alicyclic polyisocyanate include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'-, 2,4'- or 2,2'-dicyclohexyl. Methane diisocyanate or its mixture (H ₁₂ MDI), 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane or its mixture (H ₆ XDI), bis (isocyanatomethyl) norbornane (NBDI), 1,3 -Cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate and the like. I can get lost.

  Examples of the araliphatic polyisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof (XDI), 1,3- or 1,4-bis (1-isocyanato-1-methylethyl) benzene. Alternatively, aromatic aliphatic diisocyanates such as a mixture thereof (TMXDI) and ω, ω′-diisocyanato-1,4-diethylbenzene may be mentioned.

  Aromatic polyisocyanates include, for example, 4,4'-, 2,4'- or 2,2'-diphenylmethane diisocyanate or mixtures thereof (MDI), 2,4- or 2,6-tolylene diisocyanate or mixtures thereof (TDI), 4,4'-toluidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), m- or p-phenylene diisocyanate or mixtures thereof, 4,4'-diphenyl diisocyanate, 4,4'-diphenyl ether Aromatic diisocyanates such as diisocyanates are mentioned.

  Moreover, as a polyisocyanate compound, the above-mentioned various polyisocyanate compound multimers (for example, dimers, trimers, etc.), for example, the above-mentioned various polyisocyanate compounds or multimers thereof, and reaction with water. The resulting biuret modified product, the allophanate modified product produced by reaction with alcohol or the above low molecular weight polyol, the oxadiazine trione modified product produced by reaction with carbon dioxide gas, and the reaction with the above low molecular weight polyol. Examples thereof include a modified polyol product to be produced.

These polyisocyanate compounds may be used singly or in combination of two or more, preferably alicyclic polyisocyanate.
In order to react an active hydrogen component (that is, a fluorene skeleton-containing active hydrogen compound, a hydrophilic group-containing active hydrogen compound, and, if necessary, a polyol compound) and a polyisocyanate component (that is, a polyisocyanate compound), it is known. For example, the equivalent ratio of the isocyanate group of the polyisocyanate component to the active hydrogen group of the active hydrogen component (NCO / active hydrogen group) is less than 1, preferably 0.8 to 0.95. In a proportion, the active hydrogen component and the polyisocyanate component are blended and reacted.

In this reaction, the reaction temperature is set to, for example, 40 to 100 ° C., preferably 60 to 80 ° C. under normal pressure and, if necessary, in a nitrogen atmosphere, and the reaction time is preferably, for example, 5 to 24 hours. Is set to 8-10 hours. In this reaction, if necessary, a reaction solvent can be used or a reaction catalyst can be added.
As a reaction solvent, it is a low-boiling solvent that is inert to isocyanate groups, is rich in hydrophilicity, and can be easily removed, for example, alcohols such as ethanol and isopropanol, and ketones such as acetone and methyl ethyl ketone. Examples thereof include ethers such as tetrahydrofuran, cellosolves such as methyl cellosolve and ethyl cellosolve, carbitols such as methyl carbitol and ethyl carbitol, and nitriles such as acetonitrile, and the like. The amount of reaction solvent used is appropriately determined.

Examples of the reaction catalyst include known urethanization catalysts such as amine-based, tin-based, and lead-based catalysts. The amount of reaction solvent added is appropriately determined.
By this reaction, the active hydrogen component and the polyisocyanate component undergo a urethanation reaction, and the aqueous polyurethane resin of the present invention can be obtained.
The water-based polyurethane resin thus obtained has a weight average molecular weight of, for example, 5,000 to 100,000 as a standard polystyrene conversion value by GPC measurement.

Then, the aqueous polyurethane resin of the present invention was prepared as an aqueous dispersion, the resulting aqueous polyurethane resin, after neutralization of the carboxyl group thereof, dispersed in water.
The neutralization of the carboxyl group is, for example, trimethylamine, triethylamine, tri-n-propylamine, tributylamine, triethanolamine, aminomethylpropanol, aminomethylpropanediol, aminoethylpropanediol, trihydroxymethylaminomethane, monoethanolamine An organic amine such as triisopropanolamine, for example, an inorganic alkali salt such as potassium hydroxide or sodium hydroxide, or a neutralizing agent selected from ammonia or the like is added to the aqueous polyurethane resin to form a carboxyl group. A salt is formed.

The addition amount of the neutralizing agent is, for example, 0.4 to 1.2 equivalents, preferably 0.6 to 1.0 equivalents per equivalent of anionic group.
Next, in order to disperse the aqueous polyurethane resin in water, for example, while stirring the aqueous polyurethane resin, water is gradually added thereto, or water is stirred while the aqueous polyurethane resin is gradually aqueous. Add polyurethane resin. Thereby, the aqueous dispersion of an aqueous polyurethane resin is prepared. The stirring is preferably performed using a homomixer or the like so as to impart high shear.

Although the addition amount of water is suitably determined by the solid content weight of the aqueous dispersion of the desired aqueous polyurethane resin, for example, it is in the range of 20 to 500 parts by weight with respect to 100 parts by weight of the aqueous polyurethane resin.
Thus, an aqueous dispersion of the aqueous polyurethane resin in which the aqueous polyurethane resin of the present invention is dispersed in water is prepared. In addition, the pH of the aqueous dispersion of the aqueous polyurethane resin is usually about 7 to 9.

The aqueous dispersion of the aqueous polyurethane resin thus obtained is prepared so that its solid content is, for example, 10 to 40% by weight, preferably 25 to 35% by weight.
When a reaction solvent is used in the urethanization reaction, after the urethanization reaction is completed or after water dispersion, the reaction solvent is heated at an appropriate temperature, for example, under reduced pressure. Leave.

  In addition, the aqueous polyurethane resin of the present invention, or an aqueous dispersion thereof, in a range that does not impair the excellent effects of the present invention, for example, plasticizer, antifoaming agent, leveling agent, antifungal agent, rust preventive agent, Matting agent, flame retardant, thixotropic agent, tackifier, thickener, lubricant, antistatic agent, surfactant, reaction retarder, antioxidant, UV absorber, hydrolysis inhibitor, weathering stabilizer, Additives such as an anti-tacking agent can be blended as appropriate. The mixing ratio of various additives is appropriately selected depending on the purpose and application.

  And the water-based polyurethane resin of this invention obtained in this way is not specifically limited, In various industrial fields, such as a coating material and an adhesive agent, it can be used as those industrial raw materials. In addition, the aqueous polyurethane resin of the present invention can impart excellent dispersibility and stability to the pigment, and can improve optical characteristics and physical properties of the coating film. Therefore, the water-based polyurethane resin of the present invention is preferably used as a water-based ink resin or a pigment dispersant.

The resin for water-based ink or the dispersant for water-based ink of the present invention exhibits a particularly excellent effect particularly when used for a water-based ink or a pigment dispersion containing a black pigment. As a black pigment, carbon black is suitable as described later.
Hereinafter, the water-based ink of the present invention in which the water-based polyurethane resin of the present invention is used as a resin for water-based inks and the pigment dispersion of the present invention used as a pigment dispersant will be described.

The water-based ink of the present invention contains a water-based ink resin (binder), a pigment, a dispersant, a dispersion medium, and the like.
In the water-based ink of the present invention, the above-described water-based polyurethane resin of the present invention is used as the water-based ink resin. The content of the aqueous ink resin is, for example, in the range of 1 to 200 parts by weight, preferably 10 to 100 parts by weight with respect to 100 parts by weight of the pigment.

In the water-based ink of the present invention, the pigment is not particularly limited, and either an organic pigment or an inorganic pigment can be used.
Examples of organic pigments include azo pigments such as azo lake pigments, insoluble monoazo pigments, insoluble disazo pigments, condensed azo pigments, and chelate azo pigments, such as phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, and thioindigo pigments. Examples thereof include polycyclic pigments such as pigments, isoindolinone pigments, and quinophthalone pigments, for example, dye chelates such as basic dye-type chelates and acid dye-type chelates, such as nitro pigments, such as nitroso pigments.

Examples of inorganic pigments include titanium oxide, iron oxide yellow, iron oxide brown, chromium oxide, bitumen, ultramarine blue, molybdenum red, iron oxide black, yellow lead, composite oxide pigment, and carbon black.
Of these, in light resistance, isoindolinone pigments, quinacridone pigments, condensed azo pigments, phthalocyanine pigments, quinophthalone pigments, anthraquinone pigments, carbon black and the like are preferable.

  Specific examples of the organic pigment include, for example, Pigment Yellow 1 (Color Index (hereinafter referred to as CI) 11680), Pigment Yellow 3 (C.I. 11710), and Pigment Yellow 14 (C.I. 21095), Pigment Yellow 17 (C.I. 21105), Pigment Yellow 42 (C.I. 77492), Pigment Yellow 74 (C.I. 11741), Pigment Yellow 83 (C.I. 21108) Pigment Yellow 93 (C.I. 20710), Pigment Yellow 98 (C.I. 11727), Pigment Yellow 109 (C.I. 56284), Pigment Yellow 110 (C.I. 56280), Pigment・ Yellow 128 (C.I.20037), Pigment ・ Yellow 38 (C.I. 56300), Pigment Yellow 139 (C.I. 56298), Pigment Yellow 147 (C.I. 60645), Pigment Yellow 154 (C.I. 11781), Pigment Yellow 155 ( CI--), Pigment Yellow 180 (C.I. 21290), Pigment Yellow 185 (C.I. 56290), Pigment Orange 5 (C.I. 12075), Pigment Orange 13 (C.I. Pigment Orange 16 (C.I. 21160), Pigment Orange 34 (C.I. 21160), Pigment Orange 43 (C.I. 71105), Pigment Orange 61 (C.I. 11265), Pigment Orange 71 (C.I. 56120), Pigment Red 5 (C.I. 12490), Pigment Red 8 (C.I. 12335), Pigment Red 17 (C.I. 12390), Pigment Red 22 (C.I. 12315), Pigment Red 48 : 2 (C.I. 15865: 2), Pigment Red 112 (C.I. 12370), Pigment Red 122 (C.I. 73915), Pigment Red 177 (C.I. 65300), Pigment Red 202 (C.I. 73907), Pigment Red 254 (C.I. 56110), Pigment Violet 19 (C.I. 46500), Pigment Violet 23 (C.I. 51319), Pigment Blue 15 : 1 (C.I. 74160), Pigment Blue 15: 3 (C.I. 74160), Pigment Blue 15: 4 (C.I. I. 74160), Pigment Blue 60 (C.I. 69800), Pigment Green 7 (C.I. 74260), Pigment Green 36 (C.I. 74265), and the like.

Specific examples of the inorganic pigment include, for example, Pigment Yellow 42 (C.I. 77492), Pigment White 6 (C.I. 777891), Pigment Blue 27 (C.I. 77510), and Pigment Blue 29 (C.I. 77007), pigment black 7 (C.I. 77266), and the like.
Preferably, Pigment Yellow 74 (C.I. 11741), Pigment Yellow 109 (C.I. 56284), Pigment Yellow 110 (C.I. 56280), Pigment Yellow 128 (C.I. 20037) Pigment Yellow 155 (C.I.-), Pigment Yellow 180 (C.I. 21290), Pigment Red 122 (C.I. 73915), Pigment Red 202 (C.I. 73907), Pigment Violet 19 (C.I. 46500), Pigment Blue 15: 1 (C.I. 74160), Pigment Blue 15: 3 (C.I. 74160), Pigment Blue 15: 4 (C.I. 74160), Pigment Blue 60 (C.I.69800), Pigment Black (C.I.77266) and the like.

In particular, carbon black has characteristics that are not found in other carbons such as a structure, and has a great influence on physical properties, so selection is necessary. Examples of the carbon black include acetylene black, channel black, and furnace black.
The primary particle size of carbon black is 30 nm or less, particularly preferably 20 nm or less, and more preferably 16 nm or less.

  The DBP oil absorption is usually 30 mL / 100 g or more, preferably 100 mL / 100 g or less. Beyond this range, gloss is difficult to develop. When the DBP oil absorption is less than 30 mL / 100 g, it is difficult to disperse and it is difficult to obtain stability, and when it exceeds 100 mL / 100 g, the structure is developed and the average dispersed particle diameter finally reached is large. It becomes difficult to express gloss.

The primary particle diameter is a value measured by an electron microscope, and the DBP oil absorption is a value measured by a JIS K6221 A method.
Specific examples of carbon as described above include “carbon black # 2650”, “# 2600”, “# 2300”, “# 2200”, “# 1000” “# 980”, “# 970”, “# 960”. ”,“ # 950 ”,“ # 900 ”,“ # 850 ”,“ MCF88 ”,“ # 55 ”,“ # 52 ”,“ # 50 ”,“ # 47 ”,“ # 45 ”,“ # 45L ” , “# 44”, “# 33”, “# 32”, “# 30” (Mitsubishi Chemical Corporation), “MONARCH800”, “−4630”, “−430”, “−900”, “−” "1100", "-1300", "-1400", "REAGAL400R", "-660R", "MOUGGAL L" (manufactured by Cabot), "Printex-95", "-90", "-85", “−75”, “−55”, “−45”, "-300" (manufactured by Degussa), "Raven-5000ULTRAIII", "-7000", "-5750", "-5250", "-2500 URTRA", "-2000", "-1500", "- 1255 ”,“ −1250 ”,“ −1200 ”,“ −1190 URTRA ”,“ −1170 ”,“ −1020 ”(above, manufactured by Columbian), and the like.

These pigments can be used alone or in combination of two or more. The pigment content is, for example, in the range of 0.1 to 20% by weight with respect to the aqueous ink.
In the water-based ink of the present invention, it is preferable to use the water-based polyurethane resin of the present invention as the dispersant, as in the pigment dispersion described later. When using the water-based polyurethane resin of this invention, the content is 5-100 weight part with respect to 100 weight part of pigments, Preferably, it is the range of 10-60 weight part.

If the aqueous polyurethane resin of the present invention is used as a dispersant, excellent dispersibility and stability can be imparted to the pigment, and optical properties and coating film properties can be improved.
In the water-based ink of the present invention, a water-soluble polymer or a surfactant can be used as a dispersant together with the above-described water-based polyurethane resin of the present invention or separately from the water-based polyurethane resin of the present invention.

Examples of the water-soluble polymer include water-soluble polymers having ionic hydrophilic groups such as alkali metal salts such as sulfonic acid groups, carboxylic acid groups, and amino groups, ammonium salts, inorganic acid salts, and organic acid salts. It is done.
Examples of such water-soluble polymers include cellulose derivatives such as carboxymethylcellulose salt and viscose, natural polymers such as alginate, gelatin, albumin, casein, gum arabic, tonganto gum, and lignin sulfonate, cationic starch. , Starch derivatives such as starch phosphate, carboxymethyl starch salt, polyacrylate, polyvinyl sulfate, poly (4-vinylpyridine) salt, polyamide, polyallylamine salt, condensed naphthalenesulfonate, (α-methyl) styrene -Acrylate copolymer, (α-methyl) styrene-methacrylate copolymer, (α-methyl) maleate copolymer, acrylic ester-acrylate copolymer, acrylic ester-methacrylic Acid salt copolymer, methacrylate ester-acrylic acid Acid salt copolymer, methacrylate ester-methacrylate salt copolymer, styrene-itaconate copolymer, itaconic acid ester-itaconate copolymer, vinyl naphthalene-acrylate copolymer, vinyl naphthalene- Examples thereof include a methacrylate copolymer and a vinyl naphthalene-itaconate copolymer. These water-soluble polymers have a weight average molecular weight in the range of 2,000 to 1,000,000, for example.

  Furthermore, as the water-soluble polymer, for example, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl methyl ether, polyethylene glycol, polypropylene glycol, polyacrylamide, polyamine sulfone, vinyl alcohol-vinyl acetate copolymer, polyvinyl alcohol-partial formalized product, Synthetic polymers such as polyvinyl alcohol-partially butyralized, vinylpyrrolidone-vinyl acetate copolymer, cellulose derivatives such as methyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl cellulose, hydroxyalkyl starch, starch acetate, Examples include starch derivatives such as cross-linked starch and dextrin.

These water-soluble polymers can be used alone or in combination of two or more. Moreover, when using water-soluble polymer, the content is 0.01 to 20 weight% with respect to water-based ink, for example.
Examples of the surfactant include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

  Anionic surfactants include, for example, carboxylates, simple alkyl sulfonates, modified alkyl sulfonates, alkyl allyl sulfonates, alkyl sulfate esters, sulfated oils, sulfate esters, sulfated fatty acid monoglycerides, sulfated alkanol amides. Sulphated ethers, alkyl phosphate esters, alkyl benzene phosphonates, naphthalene sulfonic acid / formalin condensates.

  Examples of cationic surfactants include simple amine salts, modified amine salts, tetraalkyl quaternary ammonium salts, modified trialkyl quaternary ammonium salts, trialkyl benzyl quaternary ammonium salts, and modified trialkyl benzyl quaternary salts. Examples include quaternary ammonium salts, alkyl pyridinium salts, modified alkyl pyridinium salts, alkyl quinolinium salts, alkyl phosphonium salts, and alkyl sulfonium salts.

Examples of amphoteric surfactants include betaine, sulfobetaine, sulfate betaine and the like.
Nonionic surfactants include, for example, fatty acid monoglycerin ester, fatty acid polyglycol ester, fatty acid sorbitan ester, fatty acid sucrose ester, fatty acid alkanol amide, fatty acid polyethylene glycol glycol condensate, fatty acid amide polyethylene glycol condensate, Examples include fatty acid alcohol / polyethylene / glycol condensate, fatty acid amine / polyethylene / glycol condensate, fatty acid mercaptan / polyethylene / glycol condensate, alkyl / phenol / polyethylene / glycol condensate, and polypropylene / glycol / polyethylene / glycol condensate. .

These surfactants can be used alone or in combination of two or more. Moreover, when using surfactant, the content is the range of 0.1 to 3 weight% with respect to water-based ink, for example.
A commercially available product can be used as the styrene-acrylic dispersant, and specific examples thereof include a dispersant manufactured by Johnson Polymer Co., Ltd., and an aqueous solution type is John Crill 61J (weight molecular weight 12000, acid In the case of emulsion type 195), Joncryl 450 (weight molecular weight 100000 to 200000, acid value 100) and the like can be mentioned. Furthermore, Joncryl 67 (weight molecular weight 12500, acid value 213), Joncryl 678 (weight molecular weight 8500, acid value 215), Joncryl 586 (weight molecular weight 4600, acid value 108), Joncryl 680 (weight molecular weight 4900, acid) 215) Joncryl 683 (weight molecular weight 8000, acid value 160), Joncryl 690 (weight molecular weight 16500, acid value 240) and the like. In addition, the flaky (solid) thing is made into aqueous solution or emulsified. Examples of neutralized salts for forming an aqueous solution or emulsifying include inorganic salts such as ammonia, potassium hydroxide, lithium hydroxide, and sodium hydroxide, triethylamine, aminomethylpropanol, aminomethylpropanediol, aminoethylpropanediol, Examples thereof include organic amines such as trihydroxymethylaminomethane, monoethanolamine, triethanolamine, and triisopropanolamine.

  As a dispersion medium, water is mainly used, and other water-soluble solvents, for example, alcohols such as methanol, ethanol, isopropyl alcohol, such as ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol mono Examples include alkyl ether alcohols such as butyl ether, prolene glycol monobutyl ether, and prolene glycol monobutyl ether, for example, diols such as 1,2-pentanediol and 1,2-hexanediol.

These dispersion media are mixed with water and, if necessary, other water-soluble solvents at an appropriate ratio. The content of the dispersion medium is the remaining amount of each component with respect to the water-based ink.
Moreover, various additives are added to the water-based ink of the present invention as necessary. Examples of various additives include a penetration enhancer, a wetting agent, a pH adjuster, and the like.
As the permeation accelerator, the above-mentioned various surfactants and water-soluble solvents can be used, and further, for example, acetylene glycol compounds and polysiloxane compounds described in JP-A No. 2005-112872 can also be used.

The penetration enhancer can be used alone or in combination of two or more. Moreover, when using a penetration enhancer, the content is 0.1 to 15 weight% with respect to water-based ink, for example.
Examples of the wetting agent include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol having a number average molecular weight of 2000 or less, 1,3-propylene glycol, Examples include diols such as propylene glycol, isobutylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, mesoerythritol, and pentaerythritol.

Wetting agents can be used alone or in combination of two or more. Moreover, when using a wetting agent, the content is the range of 1-30 weight% with respect to water-based ink, for example.
Examples of the pH adjuster include potassium hydroxide, sodium hydroxide, triethanolamine and the like. The content of the pH adjuster is appropriately determined according to the target pH.

Furthermore, the water-based ink of the present invention may contain a fixing agent such as a water-soluble rosin, an antifungal agent / preservative such as sodium benzoate, an antioxidant / ultraviolet absorber such as an allophanate, a chelating agent, an antifoaming agent. Additives such as agents can be added as appropriate.
The aqueous ink of the present invention can be prepared by mixing the above-described components. For example, first, a pigment, a dispersant and a dispersion medium are mixed to prepare a pigment dispersion, and then It can be prepared by mixing the pigment dispersion and the remaining components, that is, the water-based ink resin and additives.

By preparing a pigment dispersion in advance, it is possible to ensure good dispersion of the pigment in the dispersion medium and improve the dispersibility of the pigment in the aqueous ink.
Examples of the disperser used for mixing each component include a media medium disperser and a collision disperser.
The media-media type disperser moves small-sized media such as glass, alumina, zirconia, steel, tungsten, etc. as media in a vessel at high speed, and the slurry passing between them is ground by the shearing force between the media. Type of disperser. Specific examples of such media medium type dispersers include a ball mill, a sand mill, a pearl mill, a spike mill, an agitator mill, a cobo mill, an ultra visco mill, a super apex mill, and the like.

The collision type disperser is a type of disperser in which a fluid collides with one wall surface at high speed, or fluids collide with each other at high speed to pulverize pigments and the like in the fluid. Specific examples of such a collision type disperser include a nanomizer, a homogenizer, a microfluidizer, and an optimizer.
Examples of the disperser include known dispersers other than those described above, such as a roll mill and an ultrasonic disperser.

In the water-based ink of the present invention, since the water-based polyurethane resin of the present invention is used as an ink resin, it is excellent in dispersibility and stability, and can improve optical characteristics and physical properties of the coating film.
More specifically, it is possible to improve the initial dispersibility and dispersion stability (storage stability) of the primary particle size of the pigment, and to improve brightness and white blur while improving optical density and glossiness. The optical characteristics can be improved, for example, it can be suppressed. Furthermore, it is possible to improve the physical properties of the coating film, such as improvement of uniform film forming property at room temperature.

Therefore, the water-based ink of the present invention is effectively used, for example, as an ink-jet water-based ink.
The pigment dispersion of the present invention contains a pigment, a dispersant, and a dispersion medium.
In the pigment dispersion of the present invention, at least the aqueous polyurethane resin of the present invention is used as a dispersant. The aqueous polyurethane resin of the present invention, when used as a dispersant, has an acid value of 50 to 130 KOHmg / g, preferably 60 to 100 KOHmg / g, and contains a fluorene skeleton in the aqueous polyurethane resin. The content of the fluorene skeleton of the active hydrogen compound is preferably 0.1 to 40% by weight. Even if the acid value is smaller or larger than the above range, the pigment dispersibility is lowered and stability cannot be obtained.

Moreover, a dispersing agent other than the aqueous polyurethane resin of the present invention described above can be used in combination. As the pigment and the dispersion medium, the above-described pigment and dispersion medium are used.
Furthermore, the above-mentioned additives can be added in advance to the pigment dispersion of the present invention.
In the pigment dispersion of the present invention, the content of the dispersant is, for example, in the range of 5 to 100 parts by weight, preferably 10 to 60 parts by weight, with respect to 100 parts by weight of the pigment. For example, 0.5 to 30% by weight, preferably 1 to 25% by weight, based on the pigment dispersion, and the dispersion medium is the remaining amount of each component blended.

  And since the water-based polyurethane resin of this invention is mix | blended with the pigment dispersion liquid of this invention, the outstanding dispersibility is provided with respect to the pigment. Therefore, although not particularly limited, for example, it is effectively used in various industrial fields such as synthetic leather and ink (the above-described aqueous ink dispersant).

Next, although this invention is demonstrated based on an Example and a comparative example, this invention is not limited by the following Example.
Synthesis Example 1 (Synthesis of aqueous dispersion of aqueous polyurethane resin PU1)
In a four-flask equipped with a stirrer, a Dimroth cooler, a nitrogen inlet tube, a silica gel drying tube and a thermometer, 119.70 g of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate as a polyisocyanate component, As active hydrogen components, 60.90 g of dimethylolpropionic acid, 60.04 g of bisphenoxyethanol fluorene (produced by Osaka Gas Chemical Co., Ltd.), 13.37 g of polytetramethylene glycol having a number average molecular weight of 2,000, and 300.00 g of methyl ethyl ketone as a solvent. Was added, and the mixture was heated to 80 ° C. and stirred for 12 hours under a nitrogen atmosphere.

  After confirming the disappearance of the isocyanate absorption band by infrared absorption spectrum, the temperature was lowered to 40 ° C., neutralized by adding 45.9 g of triethylamine, and then 700.00 g of water was added and dispersed using a homodisper. I let you. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 50 ° C. and 6.66 kPa, so that the solvent was not substantially contained, the fluorene skeleton content was 20% by weight, the acid value was 85 KOH mg / g, the solid content concentration was 30% by weight, and the viscosity was 200 mPa. An aqueous dispersion of s aqueous polyurethane resin PU1 was obtained.

Synthesis Examples 2 to 13 (Synthesis of aqueous dispersions of aqueous polyurethane resins PU2 to PU13)
The aqueous dispersions of the aqueous polyurethane resins PU2 to PU13 of Synthesis Examples 2 to 13 were synthesized in the same manner as in Synthesis Example 1 with the compositions and contents (blending amounts) shown in Table 1.

Examples 1 to 3 (Preparation of pigment dispersions DW1 to DW3)
Pigment dispersions DW1 to DW3 were respectively prepared by blending each component with the composition and content (blending amount) shown in Table 2 and dispersing for 10 hours using a paint conditioner. As dispersion media, 0.5 mm zirconia beads were used. The ratio of the compounding component and the media was 1: 1 by volume.

Comparative Examples 1 to 7 (Preparation of pigment dispersions DW4 to DW10)
In the composition and content (blending amount) shown in Table 2, each component is blended, and pigment dispersions DW4 to DW10 are prepared by dispersing the pigment in the same manner as in Examples 1 to 3, respectively. did.

In Table 2, demole N is an anionic surfactant of naphthalenesulfonic acid / formalin condensate (manufactured by Kao Corporation).
In Table 2, SCX-819 is a styrene-acrylate copolymer (acid value 75 KOH mg / g, manufactured by Johnson Polymer Co., Ltd.), and Jonkrill 683 is a styrene-acrylate copolymer ( Acid value 160, manufactured by Johnson Polymer Co., Ltd.), both of which are flaky, and were neutralized with potassium hydroxide and then used for the preparation of a pigment dispersion.

Carbon black having a DBP oil absorption of 77 mL / 100 g, a nitrogen adsorption specific surface area of 350 m ² / g, and a pH of 7.6 was used.
Examples 4 to 14 (Preparation of water-based inks A to K)
Water-based inks A to K were prepared by blending the respective components with the compositions and contents (blending amounts) shown in Tables 3 and 4.

Comparative Examples 8 to 10 (Preparation of water-based inks L to N)
Water-based inks L to N were prepared by blending each component with the composition and content (blending amount) shown in Table 4.

Evaluation 1) Evaluation of pigment dispersion (average particle size)
In the next evaluation, the average particle diameter was measured by Microtrac UPA ("UPA150" manufactured by Nikkiso Co., Ltd.), and D50 in the particle diameter distribution (indicating that 50% of the particles are smaller than the particle diameter). Is the value of
(viscosity)
In the next evaluation, the viscosity was measured using a TV-20 viscometer (manufactured by Toki Sangyo Co., Ltd.).
(Evaluation of initial dispersibility)
(Initial average particle size)
The initial average particle sizes of the pigment dispersions DW1 to DW10 were measured and evaluated based on the following evaluation criteria. The results are shown in Table 2.

Evaluation criteria:
Target average particle size less than 75nm ○
Target average particle size 75 nm or more and less than 85 nm
Target average particle size 85nm or more ×
(Initial viscosity)
The initial viscosities of the pigment dispersions DW1 to DW10 were measured and evaluated based on the following evaluation criteria. The results are shown in Table 2.

Evaluation criteria:
Viscosity less than 5.0 mPa · s ○
Viscosity 5.0 mPa · s or more and less than 10.0 mPa · s △
Viscosity 10.0 mPa · s or more ×
(Dispersion stability evaluation)
(Average particle size after storage)
The average particle diameters after the pigment dispersions DW1 to DW10 were stored at room temperature (25 ° C.) for 1 month and at 70 ° C. for 1 week were measured and evaluated according to the following evaluation criteria. The results are shown in Table 2.

Evaluation criteria:
Target average particle size less than 75nm ○
Target average particle size 75 nm or more and less than 85 nm
Target average particle size 85nm or more ×
(Change in viscosity over time)
The viscosity before and after storage of pigment dispersions DW1 to DW10 at room temperature (25 ° C.) for 1 month and 70 ° C. for 1 week was measured, and the change in measured values after storage after initial storage before storage was measured as follows: Evaluation was based on the evaluation criteria. The results are shown in Table 2.

Evaluation criteria:
The measured value after elapse is less than ± 3% relative to the initial value.
Measured value after elapse of more than ± 3% and less than ± 6% relative to initial value
The measured value after elapse is more than ± 6% of the initial value ×
2) Evaluation of water-based ink (average particle size)
In the next evaluation, the average particle size was measured by Microtrac UPA ("UPA150" manufactured by Nikkiso Co., Ltd.), and D50 in the particle size distribution (indicating that 50% of the particles are smaller than the particle size). Is the value of
(viscosity)
In the next evaluation, the viscosity was measured using a TV-20 viscometer (manufactured by Toki Sangyo Co., Ltd.).
[Initial ink evaluation]
(Initial average particle size)
The initial average particle diameters of the water-based inks A to N were measured and evaluated based on the following evaluation criteria. The results are shown in Tables 3 and 4.

Evaluation criteria:
Target average particle size less than 75nm ○
Target average particle size 75 nm or more and less than 85 nm
Target average particle size 85nm or more ×
(Initial viscosity)
The initial viscosities of the water-based inks A to N were measured and evaluated based on the following evaluation criteria. The results are shown in Tables 3 and 4.

Evaluation criteria:
Viscosity less than 3.0 mPa · s ○
Viscosity 3.0 mPa · s or more and less than 3.5 mPa · s △
Viscosity 3.5mPa · s or more ×
[Ink stability evaluation]
(Change in average particle size over time)
The average particle diameter before and after storage of water-based inks A to N at room temperature (25 ° C.) for 1 month and 70 ° C. for 1 week was measured. It was evaluated according to the evaluation criteria. The results are shown in Tables 3 and 4.

Evaluation criteria:
The measured value after elapse is less than ± 3% relative to the initial value.
Measured value after elapse of more than ± 3% and less than ± 6% relative to initial value
The measured value after elapse is more than ± 6% of the initial value ×
(Change in viscosity over time)
Viscosity of water-based inks A to N before and after storage at room temperature (25 ° C.) for 1 month and 70 ° C. for 1 week was measured, and changes in measured values after storage with respect to initial values before storage were evaluated as follows. Evaluated by criteria. The results are shown in Tables 3 and 4.

Evaluation criteria:
The measured value after elapse is less than ± 3% relative to the initial value.
Measured value after elapse of more than ± 3% and less than ± 6% relative to initial value
The measured value after elapse is more than ± 6% of the initial value ×
[Various physical property evaluation]
Aqueous inks A to N were coated on the surface of PM photographic paper (ink-jet glossy paper: manufactured by Seiko Epson Corporation) with a bar coater # 7 (apparent ink coating amount 16 g / m ² ). The physical properties were measured by the methods shown below. The results are shown in Tables 3 and 4.
Optical density (OD): The optical density (OD) was measured using a Macbeth reflection densitometer (RD-918). The higher the value, the higher the print density.
Glossiness (°): VG2000 manufactured by Nippon Denshoku Industries Co., Ltd., according to the specular gloss measurement method (JIS-Z8741 (1983)), the specular glossiness at an incident angle of 20 ° and a receiving angle of 20 °, an incident angle of 60 The specular gloss at a light receiving angle of 60 ° and the specular gloss at an incident angle of 85 ° and a light receiving angle of 85 ° were measured. Note that the higher the numerical value, the higher the glossiness.
Color difference (L * a * b * value): L * a * b * value was measured using Spectraflash 600 OLUS manufactured by DATACOLOR. Note that the higher the L * value, the brighter and the lower the L * value, the darker. That is, the lower the L * value, the blacker.
Blackness: The natural light of the north window was applied to the surface after coating, and it was visually observed while changing the angle, and evaluated according to the following evaluation criteria.

Evaluation criteria:
Even with the angle, white blur and hue density change cannot be confirmed.
Depending on the angle, white blur and hue density change were confirmed ×

Claims (7)

An active hydrogen component comprising a fluorene skeleton-containing active hydrogen compound having a fluorene skeleton and having an active hydrogen group; and a hydrophilic group-containing active hydrogen compound having a carboxyl group and an active hydrogen group;
Obtained as an aqueous dispersion by reaction with a polyisocyanate component containing a polyisocyanate compound,
The acid value is 10 to 130 KOHmg / g,
An aqueous polyurethane resin characterized by being used as a pigment dispersant and / or a resin for aqueous ink . The aqueous polyurethane according to claim 1, wherein the fluorene skeleton-containing active hydrogen compound is 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene. Polyisocyanate compound, characterized in that a cycloaliphatic diisocyanate, the aqueous polyurethane resin according to claim 1 or 2. The aqueous polyurethane resin according to any one of claims 1 to 3 , wherein the content of the fluorene skeleton of the fluorene skeleton-containing active hydrogen compound in the aqueous polyurethane resin is 0.1 to 60% by weight. Used as a pigment dispersant,
The acid value is 50-130 KOHmg / g,
The content of the fluorene skeleton of fluorene skeleton-containing active hydrogen compound in the aqueous polyurethane resin, characterized in that 0.1 to 40 wt%, aqueous polyurethane resin according to any one of claims 1 to 4. 5. A water-based ink comprising the water-based polyurethane resin according to claim 1 and a pigment. A pigment dispersion comprising the aqueous polyurethane resin according to claim 5 and a pigment.