JP2014172987A - Inkjet ink composition and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet ink composition which can be used preferably for production of a recording material which is excellent in both of optical density (image density) and rub resistance by applying the inkjet ink composition to low absorptive coated paper and which is excellent in discharge stability by an inkjet method, and to provide a recording material formed by forming a print part excellent in both of optical density (image density) and rub resistance on low absorptive coated paper as a recording medium.SOLUTION: The inkjet ink composition is recorded to the low absorptive coated paper, and comprises: a self-dispersion pigment; resin particles; and wax particles. A glass transition point of resin material forming the resin particle is -150°C to 10°C, and an average particle diameter of the wax particle is 100 nm or more and 250 nm or less.

Description

  The present invention relates to an inkjet ink composition and a recording method.

The recording method using the ink jet method has advantages such as low noise and easy recording speed, density, and color.
As ink-jet ink (recording liquid), one containing resin fine particles and wax fine particles has been proposed in order to improve abrasion resistance and the like (see, for example, Patent Document 1).
On the other hand, as a recording medium, low-absorbency coated paper such as matte paper has the characteristics that gloss is suppressed, calm atmosphere, elegant impression, and eyes are hard to get tired even when viewed for a long time. It is used.
However, although the above ink can obtain a sufficient optical density (image density) when plain paper is used as a recording medium, it is sufficient when applied to low-absorbency coated paper. There is a problem that the density (image density) cannot be obtained.

JP 2002-301857 A

  An object of the present invention is excellent in ejection stability by an ink jet method, and is suitable for producing a recorded matter excellent in both optical density (image density) and abrasion resistance by being applied to a low-absorbency coated paper. In addition, an ink-jet ink composition that can be used for printing is provided, and a printed part having excellent optical density (image density) and abrasion resistance is formed on a low-absorbency coated paper as a recording medium. Is to provide a record.

Such an object is achieved by the present invention described below.
The inkjet ink composition of the present invention is an inkjet ink composition recorded on a low-absorbency coated paper,
A self-dispersing pigment, resin particles, and wax particles,
The glass transition point of the resin material constituting the resin particles is −150 ° C. or more and 10 ° C. or less,
The wax particles have an average particle diameter of 100 nm to 250 nm.

  As a result, it is excellent in ejection stability by the ink jet method, and can be suitably used for the production of recorded matter that is excellent in both optical density (image density) and abrasion resistance by being applied to low-absorbency coated paper. To provide an inkjet ink composition that can be used, and to provide a recorded matter in which a printed part having excellent optical density and abrasion resistance is formed on a low-absorbency coated paper as a recording medium. Can do.

In the ink-jet ink composition of the present invention, the resin particles are preferably composed of a styrene-acrylic copolymer.
Thereby, a resin particle forms a coating film in a printing part more suitably, and can make especially excellent the abrasion resistance of the styrene part of a styrene-acrylic-type copolymer.
In the inkjet ink composition of the present invention, the resin particles preferably have an average particle size of 180 nm or more and 250 nm or less.
Thereby, even if the resin particles form a coating film on the printing surface of the low-absorbency coated paper, an effect that the optical density is hardly lowered can be obtained.

In the inkjet ink composition of the present invention, the melting point of the wax constituting the wax particles is preferably 60 ° C. or higher and 140 ° C. or lower.
As a result, the storage stability of the wax particles can be made particularly excellent, and the abrasion resistance of the image can be made more excellent.
In the ink-jet ink composition of the present invention, the wax particles preferably contain a polyethylene wax.
Thereby, the wax particles are more effectively deformed by applying pressure to the printing portion, and the sliding effect is more effectively exhibited.

In the inkjet ink composition of the present invention, when the content of the resin particles is X _R [mass%] and the content of the wax particles is X _W [mass%], the relationship of X _R > X _W is satisfied. It is preferable.
As a result, the resin particles fix the wax particles, and the effect of deforming the wax particles can be exhibited more remarkably, and a higher rubbing effect can be obtained by the sliding effect of the wax particles in addition to the fixability of the resin particles. It is done.

In the ink-jet ink composition of the present invention, the sum of the resin particle content and the wax particle content is preferably 1.0% by mass or more and 6.0% by mass or less.
As a result, it is possible to achieve both good rub resistance and good ejection stability at a higher level.
The inkjet ink composition of the present invention preferably further contains a pyrrolidone derivative.
Thereby, the dry aggregation of the self-dispersing pigment at the ink discharge portion of the recording apparatus can be alleviated and the discharge stability can be further improved.

In the inkjet ink composition of the present invention, the content of the pyrrolidone derivative is preferably 3% by mass or more and 7% by mass or less.
As a result, good ejection stability can be more reliably obtained even after idle time in printing, that is, after a specific non-ejection time of ink.
The inkjet ink composition of the present invention preferably further contains an amine derivative.
Thereby, the optical density (image density) of the printing part formed by giving the inkjet ink composition to the low-absorbency coated paper can be made particularly high.
In the inkjet ink composition of the present invention, the content of the amine derivative is preferably 1.5% by mass or more and 3.5% by mass or less.
Thereby, the optical density (image density) of the printing part formed by giving an inkjet ink composition to the low-absorbency coated paper can be further increased.

The ink-jet ink composition of the present invention preferably further contains 1,2-alkanediol and / or glycol ether having 4 to 6 carbon atoms.
As a result, when the ink-jet ink composition is applied onto the low-absorbency coated paper, the pigment, resin particles, and wax particles can be more uniformly applied and spread, thereby forming a better image. Can do.
The recording method of the present invention is characterized in that the inkjet ink composition of the present invention is applied to a low-absorbency coated paper.
Thereby, it is possible to provide a recorded matter in which a printed portion having excellent optical density (image density) and abrasion resistance is formed on a low-absorbency coated paper as a recording medium.

Hereinafter, preferred embodiments of the present invention will be described.
<< Inkjet ink composition >>
First, the ink-jet ink composition of the present invention will be described.
The ink-jet ink composition of the present invention is ejected by an ink-jet method and is applied onto a low-absorbency coated paper.
The inkjet ink composition of the present invention includes a self-dispersing pigment, resin particles, and wax particles, and a glass transition point of a resin material constituting the resin particles is −150 ° C. or more and 10 ° C. or less, The average particle diameter of the wax particles is 100 nm or more and 250 nm or less.

  As described above, the present invention is characterized in that a self-dispersing pigment is used as a coloring material (coloring agent) and resin particles and wax particles satisfying predetermined conditions are included. As a result, the ink jet ink composition is excellent in ejection stability by the ink jet method, and even when a low-absorbency coated paper such as mat paper is used as a recording medium, Both optical density (image density) and abrasion resistance can be made excellent. To explain in more detail, the low-absorbency coated paper has the characteristics that the gloss is suppressed, has a calm atmosphere, an elegant impression, and the eyes are less tired even when viewed for a long time. Conventionally, when printing using ink, there was a problem that a sufficient optical density (image density) could not be obtained, while in the present invention while taking advantage of the low-absorbency coated paper, Both optical density (image density) and abrasion resistance can be made excellent. This is considered to be due to the following reasons. In other words, since the low-absorbency coated paper has many pores, the ink colorant penetrates into the inside of the recording medium together with the liquid component due to the capillary phenomenon in the conventional ink. On the other hand, in the ink-jet ink composition according to the present invention, such a phenomenon can be effectively prevented / suppressed by including resin particles and wax particles satisfying predetermined conditions in addition to the self-dispersing pigment. The excellent effects as described above can be obtained by satisfying all the above conditions, and the excellent effects as described above cannot be obtained when one of the above conditions is not satisfied.

For example, when another color material is included instead of the self-dispersing pigment, the aggregation of the color material cannot proceed efficiently on the low-absorbency coated paper, so that a sufficient optical density (image density) is obtained. I can't.
Further, when the resin particles are not included, the fixing property of the coloring material to the recording medium (low-absorbent coated paper) becomes insufficient, and the recorded material cannot have excellent abrasion resistance.
In addition, when the wax particles are not included, it becomes impossible to improve the slipperiness of the printed portion formed using the ink-jet ink composition, so that the recorded material has excellent abrasion resistance. I can't. In addition, for example, when a plurality of recorded materials are stored in an overlapping manner, unintended transfer of the printing unit is likely to occur.

Moreover, even if it is a case where a resin particle is included, discharge stability will fall that the glass transition point of the resin material which comprises a resin particle is less than the said lower limit.
Even when the resin particles are included, if the glass transition point of the resin material constituting the resin particles exceeds the upper limit, the fixability to the recording medium (low-absorbent coated paper) becomes insufficient, and recording is performed. The rub resistance of an object cannot be made excellent.

Even when the wax particles are included, if the average particle diameter of the wax particles is less than the lower limit, the self-dispersion pigment can be effectively prevented / suppressed from entering the low-absorbency coated paper. And the optical density (image density) of the printed part cannot be made sufficiently excellent.
Even when the wax particles are included, if the average particle diameter of the wax particles exceeds the upper limit, the ejection stability by the ink jet method is significantly reduced.

  In the present invention, the low-absorbency coated paper means calcium carbonate, clay, kaolin, white carbon, talc, magnesium carbonate, barium carbonate, barium sulfate, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, hydroxide It has a layer (surface layer) containing one or more inorganic particles selected from zinc, zinc oxide, and titanium oxide. More preferably, at least one selected from calcium carbonate, clay and kaolin is used. By including these materials, it is possible to obtain a low-absorbency coated paper (for example, matte paper) with suppressed absorbency and gloss.

In the present specification, “low absorption” indicates “a recording medium having a water absorption amount of 10 mL / m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method”. This Bristow method is the most popular method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Paper Pulp Technology Association (JAPAN TAPPI). For details of the test method, refer to Standard No. of “JAPAN TAPPI Paper Pulp Test Method 2000”. 51 "Paper and paperboard-Liquid absorbency test method-Bristow method".
In the present invention, the average particle diameter means a volume-based average particle diameter. An average particle diameter can be calculated | required by the measurement using Nanotrac150 (made by Microtrac), for example.

Hereinafter, the components of the inkjet ink composition of the present invention will be described in detail.
[Self-dispersing pigment]
The ink-jet ink composition of the present invention contains a self-dispersing pigment as a coloring material.
Self-dispersed pigments are more likely to aggregate on the recording medium (low-absorbent coated paper) than other colorants, so the optical density (image density) of the printed part formed using the inkjet ink composition It is advantageous in increasing Moreover, since the viscosity of the ink composition can be easily adjusted to an appropriate range by using the self-dispersing pigment, the handling is easy. Further, the self-dispersing pigment can be uniformly dispersed in the ink composition without separately adding a dispersant. The term “dispersed” as used herein refers to a state in which the self-dispersing pigment is stably present in the dispersion medium without a dispersant, and not only in a dispersed state but also in a dissolved state. Including things. The ink composition containing the self-dispersing pigment has a higher dispersion stability and the viscosity of the ink composition is moderate compared to a normal ink composition containing a pigment other than the self-dispersing pigment and a dispersing agent. Therefore, it is possible to contain more pigment, which is advantageous in forming an image having excellent color development.
In the present invention, the self-dispersing pigment is one or two selected from the group consisting of carbonyl group, carboxyl group, aldehyde group, hydroxyl group, sulfone group, ammonium group, and salts thereof on the surface thereof. It refers to a surface-modified pigment in which a functional group of more than one kind is bonded directly or indirectly through an alkyl group, an aryl group or the like.

  Examples of pigments that can form a self-dispersing pigment include carbon black, azo lake, insoluble azo pigment, condensed azo pigment, chelate azo pigment, phthalocyanine pigment, perylene pigment, perinone pigment, quinacridone pigment, thioindigo pigment, isoindolinone pigment, and quinofullerone. Pigments, dioxazine pigments, anthraquinone pigments, nitro pigments, nitroso pigments, organic pigments such as aniline black, titanium white, zinc white, lead white, carbon black, Bengala, vermilion, vermilion, cadmium red, yellow lead, ultramarine, cobalt blue, cobalt Examples include inorganic pigments such as purple and zinc chromate.

  Self-dispersed pigments can be prepared by coordinating functional groups or molecules containing functional groups to the surface of the pigment, chemical bonding such as grafting, etc., by physical or chemical treatment such as vacuum plasma. Can be obtained. For example, it can be obtained by the method described in JP-A-8-3498. Moreover, as a self-dispersion pigment, it is also possible to use a commercial item, for example, "Microjet CW1", "Microjet CW2" manufactured by Orient Chemical Industry Co., Ltd., "CAB-O-" manufactured by Cabot Corporation. JET 200 "," CAB-O-JET 300 ", etc. can be used.

Hereinafter, a specific example of the method for preparing the self-dispersing pigment will be described.
First, add a pigment (not a self-dispersing pigment, a pigment before surface modification) to the solvent, and apply high-speed shear dispersion with a high-speed mixer or impact-disperse with a bead mill or jet mill. A slurry-like pigment dispersion is obtained. While slowly stirring the pigment dispersion, a treatment agent containing sulfur (sulfamic acid, fuming sulfuric acid, sulfuric acid, chlorosulfuric acid, fluorosulfuric acid, amidosulfuric acid, etc.) is added, and the pigment dispersion is heated to 60 ° C. or higher and 200 ° C. or lower. The dispersibility-imparting group is introduced to the pigment surface by heat treatment. After removing the solvent from the pigment dispersion, the self-dispersing pigment can be obtained by removing the treatment agent containing sulfur by repeating washing with water, ultrafiltration, reverse osmosis, centrifugation, filtration and the like.
The average particle size of the self-dispersing pigment is preferably 10 nm or more and 300 nm or less, and more preferably 40 nm or more and 150 nm or less. Thereby, the storage stability of the inkjet ink composition and the ejection stability by the inkjet method can be made particularly excellent.

  The content of the self-dispersing pigment in the inkjet ink composition of the present invention is preferably 2.0% by mass or more and 9.0% by mass or less, and preferably 4.0% by mass or more and 7.0% by mass or less. Is more preferable, and it is further more preferable that they are 5.5 mass% or more and 6.5 mass% or less. When the content of the self-dispersing pigment is within the above range, the ejection stability by the ink jet method and the image density in the printing unit can be compatible at a higher level. In addition, when the inkjet ink composition contains a plurality of types of self-dispersing pigments, it is preferable that the sum of these contents is included in the above range.

[Resin particles]
The inkjet ink composition of the present invention includes resin particles that satisfy predetermined conditions.
Such resin particles mainly have a function of improving the abrasion resistance of the low-absorbency coated paper and preventing the optical density from being lowered. The resin particles are preferably dispersed in an emulsion state.

  Examples of the resin material constituting such resin particles include styrene-acrylic copolymers, styrene-butadiene copolymers, urethane resins, polyester resins, vinyl acetate resins, vinyl chloride resins, and the like. Of these, styrene-acrylic copolymers are preferred. As a result, the abrasion resistance of the low-absorbency coated paper can be further improved, and the optical density can be more effectively prevented from decreasing.

As described above, the glass transition point of the resin material constituting the resin particles may be −150 ° C. or more and 10 ° C. or less, preferably −100 ° C. or more and 5 ° C. or less, and −50 ° C. or more and 5 ° C. or less. The following is more preferable. Thereby, the effects as described above are more remarkably exhibited.
The average particle size of the resin particles is preferably from 180 nm to 250 nm, more preferably from 180 nm to 220 nm, and even more preferably from 180 nm to 200 nm. Thereby, even if the resin particle forms a coating film on the low-absorbent coated paper printing surface, an effect that the optical density is hardly lowered can be obtained.

  The content of the resin particles in the inkjet ink composition of the present invention is preferably 1.0% by mass or more and 5.0% by mass or less, and preferably 1.0% by mass or more and 3.0% by mass or less. More preferred. When the content of the resin particles is within the above range, the resin particles not only improve the abrasion resistance by forming a coating on the printing surface of the low-absorbency coated paper, but also the inkjet ink composition from the discharge device. The discharge stability of the object is particularly excellent. In addition, when an inkjet ink composition contains multiple types of resin particle, it is preferable that the sum total of these content rates is contained in the said range.

[Wax particles]
The inkjet ink composition of the present invention includes wax particles that satisfy predetermined conditions.
Such wax particles mainly have a function of improving the abrasion resistance of the recorded matter produced using the inkjet ink composition.
Examples of the wax constituting such wax particles include hydrocarbon waxes such as ozokerite, cercin, paraffin wax, microwax, microcrystalline wax, petrolatum, Fischer-Tropsch wax, carnauba wax, rice wax, and methyl laurate. , Methyl myristate, methyl palmitate, methyl stearate, butyl stearate, candelilla wax, cotton wax, wood wax, beeswax, lanolin, montan wax, fatty acid ester, polyglycerin fatty acid ester, etc. wax, polyethylene wax, Olefin wax such as polypropylene wax, oxidized polyethylene wax, oxidized polypropylene wax, 12-hydroxystearic acid amide, steer Phosphate amide, amide waxes such as phthalic anhydride imide, laurone, ketone waxes such as stearone, although ether-based wax, and the like, among them, polyethylene is preferable. Thereby, the wax particles are more effectively deformed by applying pressure to the printing portion, and the sliding effect is more effectively exhibited.

As described above, the average particle diameter of the wax particles may be 100 nm or more and 250 nm or less, but is preferably 180 nm or more and 250 nm or less, and more preferably 200 nm or more and 250 nm or less. Thereby, the effects as described above are more remarkably exhibited.
The melting point of the wax constituting the wax particles is preferably 60 ° C. or higher and 140 ° C. or lower, and more preferably 80 ° C. or higher and 120 ° C. or lower. As a result, the storage stability of the wax particles can be made particularly excellent, and the abrasion resistance of the image can be made more excellent.
The glass transition point of the resin material constituting the wax particles is preferably −110 ° C. or higher and −20 ° C. or lower, and more preferably −100 ° C. or higher and −50 ° C. or lower. Thereby, since normal temperature becomes more than a glass transition temperature, when a pressure is applied to a printing part, a wax particle deform | transforms more suitably and the abrasion resistance by a sliding effect further improves.

  The content of the wax particles in the ink-jet ink composition of the present invention is preferably 0.1% by mass or more and 1.0% by mass or less, and preferably 0.2% by mass or more and 0.5% by mass or less. More preferred. When the content of the wax particles is a value within the above range, the wax particles are more preferably deformed by applying pressure to the printing portion, and the abrasion resistance due to the sliding effect is improved. The ejection stability of the inkjet ink composition is further improved. In addition, when the inkjet ink composition includes a plurality of types of wax particles, it is preferable that the sum of these contents is included in the above range.

Further, when the resin particle content in the inkjet ink composition is X _R [mass%] and the wax particle content in the inkjet ink composition is X _W [mass%], the relationship X _R > X _W Is preferable, 1 <X _R / X _W ≦ 50 is more preferable, 1.5 ≦ X _R / X _W ≦ 15 is more preferable, and 2 ≦ X _R / X _W ≦ 15 is satisfied. It is most preferable to satisfy this relationship. By satisfying such a relationship, in addition to improving the abrasion resistance, the ejection stability of the inkjet ink composition from the ejection device is further improved. On the other hand, if the value of X _R / X _W is too small, the amount of resin for fixing the wax particles to the printing surface is small, and the abrasion resistance may not be sufficiently improved. On the other hand, if the value of X _R / X _W is too large, the resin particles form a film by drying, so that the ejection stability of the inkjet ink composition from the ejection device may be reduced.

  The sum of the resin particle content in the inkjet ink composition and the wax particle content in the inkjet ink composition is preferably 1.0% by mass or more and 6.0% by mass or less. More preferably, the content is 2% by mass or more and 3.5% by mass or less. Thereby, in addition to the improvement in abrasion resistance, the ejection stability of the inkjet ink composition from the ejection device is further improved.

[water]
The inkjet ink composition of the present invention may contain water. Thereby, the dispersion stability of the self-dispersing pigment, the resin particles and the wax particles as described above, the storage stability of the inkjet ink composition, and the discharge stability can be made particularly excellent.
The water content in the inkjet ink composition is preferably 50% by mass or more and 90% by mass or less, and more preferably 60% by mass or more and 80% by mass or less. Thereby, the image density of the printing part formed using an inkjet ink composition can be made especially high, making the storage stability and discharge stability of an inkjet ink composition especially excellent. On the other hand, when the content of water is less than the lower limit value, the storage stability and ejection stability of the inkjet ink composition tend to decrease. If the water content exceeds the upper limit, depending on the type of the self-dispersing pigment, it may be difficult to increase the image density of the printed portion formed using the inkjet ink composition. There is.

[Pyrrolidone derivatives]
The ink-jet ink composition of the present invention preferably contains a pyrrolidone derivative. As a result, the dry aggregation of the self-dispersing pigment at the ink gas / liquid interface at the discharge portion of the ink discharge apparatus is alleviated, and the discharge stability is further improved.
Examples of the pyrrolidone derivative include 2-pyrrolidone, N-methylpyrrolidone (1-methyl-2-pyrrolidone), 1-ethyl-2-pyrrolidone 1, 1-vinyl-2-pyrrolidone and the like. -Pyrrolidone is preferred. Thereby, the effect of alleviating the dry aggregation of the self-dispersing pigment is more remarkably exhibited.

  The content of the pyrrolidone derivative in the inkjet ink composition is preferably 3% by mass or more and 7% by mass or less, and more preferably 3% by mass or more and 6% by mass or less. When the content of the pyrrolidone derivative is a value within the above range, the effect of alleviating dry aggregation of the self-dispersing pigment is more remarkably exhibited. In addition, when an inkjet ink composition contains multiple types of pyrrolidone derivatives, it is preferable that the sum total of these content rates is contained in the said range.

[Amine derivative]
The ink-jet ink composition of the present invention preferably contains an amine derivative. Thereby, the optical density (image density) of the printing part formed by giving the inkjet ink composition to the low-absorbency coated paper can be made particularly high.
Examples of the amine derivative include triisopropanolamine, triethylamine, and triethanolamine, among which triisopropanolamine is preferable. Thereby, the optical density (image density) of the printing part formed by giving an inkjet ink composition to the low-absorbency coated paper can be further increased.

  The content of the amine derivative in the inkjet ink composition is preferably 1.5% by mass or more and 3.5% by mass or less, and more preferably 2.0% by mass or more and 3.0% by mass or less. When the content of the pyrrolidone derivative is a value within the above range, the optical density (image density) of the printed portion formed by applying the inkjet ink composition to the low-absorbency coated paper may be further increased. it can. In addition, when an inkjet ink composition contains multiple types of amine derivatives, it is preferable that the sum total of these content rates is contained in the said range.

[Other ingredients]
The inkjet ink composition of the present invention may contain components other than those described above (other components).
Examples of such components include a dispersant, an antiseptic / antifungal agent, a pH adjuster, a chelating reagent, a rust preventive agent, an ultraviolet absorber, an antifoaming agent, a surface tension adjusting agent, a polysiloxane compound, glycerin, and trimethylolpropane. And polyhydric alcohols such as diethylene glycol and triethylene glycol, and coloring materials (coloring agents) other than self-dispersing pigments.

Among these, the ink-jet ink composition preferably contains 1,2-alkanediol and / or glycol ether having 4 to 6 carbon atoms. As a result, the ink penetrates more suitably into the inside of the recording medium, and the coating efficiency of the ink on the recording medium is further improved.
Examples of the 1,2-alkanediol having 4 to 6 carbon atoms include 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, and the like. -Hexanediol is particularly preferred. Thereby, the effects as described above are more remarkably exhibited.

  Examples of glycol ethers include diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol mono n-butyl ether, diethylene glycol di n-butyl ether, diethylene glycol butyl methyl ether, dipropylene glycol monomethyl. Ether, dipropylene glycol monopropyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, tripropylene glycol monobutyl ether, Examples include raethylene glycol monomethyl ether, pentaethylene glycol monomethyl ether, pentaethylene glycol monobutyl ether, hexaethylene glycol monomethyl ether, and tetraethylene glycol dimethyl ether. Among them, diethylene glycol mono n-butyl ether, dipropylene glycol monopropyl ether, triethylene glycol Particularly preferred are ethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, and pentaethylene glycol monobutyl ether. Thereby, the effects as described above are more remarkably exhibited.

  When the ink-jet ink composition contains 1,2-alkanediol and / or glycol ether having 4 to 6 carbon atoms, the total content thereof is 1% by mass or more and 15% by mass or less. Is preferable, and it is more preferable that it is 2 mass% or more and 12 mass% or less. As a result, pigments, resin particles, wax particles and the like can be more satisfactorily penetrated into the recording medium, and the color development and abrasion resistance uniformity of the entire image can be made particularly excellent.

  Examples of antiseptic / antifungal agents include organic sulfur, organic nitrogen sulfur, organic halogen, haloallylsulfone, iodopropargyl, N-haloalkylthio, benzothiazole, nitrile, pyridine, 8- Oxyquinoline, isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiadiazine, anilide, adamantane, dithiocarbamate, brominated indanone And compounds such as benzyl bromacetate and inorganic salts. Examples of the organic halogen compound include sodium pentachlorophenol, and examples of the pyridine oxide compound include sodium pyridinethione-1-oxide, zinc pyridinethione-1-oxide, and isothiazoline-based compounds. Examples of the compound include an amine salt of 1-benzisothiazolin-3-one, 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, and 5-chloro-2-methyl. -4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4 -Isothiazoline-3-one calcium chloride and the like . Other antiseptic / antifungal agents include sodium dehydroacetate, sodium sorbate, sodium benzoate and the like.

  When the ink-jet ink composition contains a pH adjuster, the storage stability of the ink-jet ink composition can be made particularly excellent. Moreover, the reliability of the recorded matter manufactured using the inkjet ink composition can be made particularly excellent.

  Examples of the pH adjuster include alkanolamines such as diethanolamine, triethanolamine, dimethylethanolamine, and diethylethanolamine; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and lithium hydroxide; Examples include ammonium hydroxide; carbonates of alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate; aminosulfonic acids such as taurine;

Examples of the chelating reagent include disodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracil diacetate, and the like.
Examples of the antirust agent include acidic sulfites, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite, and benzotriazole compounds.

Examples of ultraviolet absorbers include benzophenone compounds, cinnamic acid compounds, triazine compounds, stilbene compounds, so-called fluorescent brighteners (compounds that absorb ultraviolet rays typified by benzoxazole compounds), and the like. Is mentioned.
Examples of antifoaming agents include highly oxidized oil compounds, glycerin fatty acid ester compounds, fluorine compounds, silicone compounds, and acetylene compounds.

Examples of the surface tension adjusting agent include a surfactant, and examples thereof include an anionic surfactant, an amphoteric surfactant, a cationic surfactant, and a nonionic surfactant.
Examples of the anionic surfactant include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acylmethyl taurate, alkyl sulfate poly Oxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkylaryl sulfonate, diethyl Examples include sulfosuccinate, diethylhexylsylsulfosuccinate, and dioctylsulfosuccinate.

Examples of the amphoteric surfactant include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, and others. Examples include imidazoline derivatives.
Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

  Nonionic surfactants include, for example, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, and the like. Ether surfactants: polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate Ester surfactants such as rate; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne- , 6-diol, 3,5-dimethyl-1-hexyne-3-acetylene glycol (alcohol) based surfactants such as ol.

  In addition, the surface tension (surface tension at 25 ° C.) of the inkjet ink composition of the present invention is preferably 20 mN / m or more and 50 mN / m or less, and more preferably 20 m or more and 40 mN / m or less. The surface tension of the ink-jet ink composition can be determined, for example, by measurement according to JIS K3362 using a surface tension meter CBVP-A3 (manufactured by Kyowa Interface Science Co., Ltd.).

The inkjet ink composition of the present invention preferably has a viscosity (viscosity at 25 ° C.) of 2 mPa · s or more and 20 mPa · s or less. As a result, the ejection stability (e.g., ejection volume stability, flight characteristics of droplets), ejection response (response speed, high frequency compatibility (frequency characteristics), etc.), etc. of the inkjet ink composition are particularly excellent. be able to. In addition, the viscosity of an inkjet ink composition can be calculated | required by the measurement based on JISZ8809 using a vibration type viscometer.
The inkjet ink composition of the present invention may be applied to the inkjet method as it is, or may be used after being diluted.

≪Recording method≫
Next, the recording method of the present invention will be described.
The recording method of the present invention is characterized in that the inkjet ink composition of the present invention is applied to a low-absorbency coated paper.
As a result, a recording method capable of efficiently producing a recorded matter in which a printing portion having excellent optical density (image density) and abrasion resistance is formed on a low-absorbency coated paper as a recording medium. Can be provided.

The inkjet ink composition is applied by an inkjet method.
In particular, low-absorptive coated paper such as matte paper has the features that it has low gloss, has a calm atmosphere, an elegant impression, and is less tiring even when viewed for a long time. However, in the past, when a low-absorbency coated paper was used as a recording medium, there was a problem that sufficient optical density (image density) could not be obtained, but the present invention solves such a problem. can do.

  The low-absorbency coated paper is calcium carbonate, clay, kaolin, white carbon, talc, magnesium carbonate, barium carbonate, barium sulfate, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, zinc oxide, and It has a layer (surface layer) containing one or more inorganic particles selected from titanium oxide. More preferably, it contains one or more selected from calcium carbonate, clay and kaolin. More preferably, it does not have a glossy layer using silica or alumina particles as in mat paper.

Moreover, it is preferable that the low-absorbency coated paper is produced by applying a coating obtained by mixing the inorganic particles and an adhesive such as starch to a substrate.
The average particle size of the inorganic particles is preferably 5 nm or more and 15000 nm or less, and more preferably 10 nm or more and 10,000 nm or less.
The basis weight of the coating material (one side) is preferably from 200 g / ^{m 2} or less, 100 g / ^{m 2} or less is more preferable, and even more preferably 20 g / ^{m 2} or more 60 g / ^{m 2} or less.

≪Recordings≫
Next, the recorded matter according to the present invention will be described.
The recorded matter according to the present invention is produced by applying the above-described inkjet ink composition of the present invention to a low-absorbency coated paper. Thereby, it is possible to provide a recorded matter in which a printed portion having excellent optical density (image density) and abrasion resistance is formed on a low-absorbency coated paper as a recording medium.

As mentioned above, although this invention was demonstrated based on suitable embodiment, this invention is not limited to these.
For example, in the above-described embodiment, the case where water is included as the dispersion medium has been mainly described. However, the inkjet ink composition of the present invention may include components other than water as the dispersion medium.

[1] Preparation of inkjet ink composition An inkjet ink composition was prepared as follows.
Example 1
Water, carbon black (manufactured by Orient Chemical Industry Co., Ltd.) as a self-dispersing pigment into which a carboxyl group has been introduced, resin particles composed of styrene-acrylic copolymers listed in Table 1, Wax particles composed of polyethylene, glycerin, trimethylolpropane, 2-pyrrolidone as a pyrrolidone derivative, 1,2-hexanediol as a 1,2-alkanediol having 4 to 6 carbon atoms, Olfine E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) as an acetylene glycol surfactant, Surfynol DF110D (manufactured by Nissin Chemical Industry Co., Ltd.) as an acetylene glycol surfactant, and triisopropanolamine as an amine derivative The ink-jet ink composition was obtained by mixing.
(Examples 2 to 13)
The inkjet ink composition was the same as in Example 1 except that the composition shown in Tables 1 and 2 was adjusted by adjusting the type and amount of components used for the preparation of the inkjet ink composition. Was prepared.

(Comparative Examples 1-8)
The inkjet ink composition was the same as in Example 1 except that the composition shown in Tables 2 and 3 was adjusted by adjusting the types and amounts of components used in the preparation of the inkjet ink composition. Was prepared.
Tables 1, 2 and 3 collectively show the compositions of the inkjet ink compositions of the above Examples and Comparative Examples.

  In the table, carbon black as a self-dispersing pigment is "CB", styrene-acrylic copolymer is "St-Ac", styrene-butadiene copolymer is "St-Bd", and urethane resin is " PU ”, polyethylene“ PE ”, glycerin“ GL ”, trimethylolpropane“ TMP ”, 2-pyrrolidone“ Pyr ”, 1,2-alkanediol 1,2-alkanediol having 4 to 6 carbon atoms -Hexanediol "1,2-HD", Olphine E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) as acetylene glycol surfactant, "E1010", Surfynol DF110D (Nisshin Chemical Co., Ltd.) as acetylene glycol surfactant “DF110D” is indicated by “Industry Co., Ltd.”, and “TPA” is indicated by triisopropanolamine.

  In addition, about 25 degreeC surface tension about the inkjet ink composition of each said Example (surface tension calculated | required by the measurement based on JISK3362 using surface tension meter CBVP-A3 (made by Kyowa Interface Science Co., Ltd.)) All were included in the range of 25 mN / m or more and 40 mN / m or less. In addition, the viscosity at 25 ° C. (viscosity obtained by measurement in accordance with JIS Z8809 using a vibration viscometer) of the ink-jet ink compositions of the above examples was 2 mPa · s to 20 mPa · s. It was included in the following ranges. Moreover, the average particle diameter was calculated | required by the measurement using Nanotrac150 (made by Microtrac).

[2] Evaluation [2.1] Discharge stability The inkjet ink composition of each of the above Examples and Comparative Examples is an inkjet printer that is an inkjet recording printer (product name “PX-H6000”, manufactured by Seiko Epson Corporation). The inside of the head was filled. After filling, a ruled line was recorded after printing a nozzle check pattern to confirm that there was no filling failure or nozzle clogging. Thereafter, the discharging operation was stopped for 5 seconds, and ruled lines were recorded again. Then, the ink landing deviation was evaluated by comparing both ruled lines.
A: Ink landing deviation in the first and second times is within 40 μm B: Ink landing deviation in the first and second time is 40 μm or more C: Second ink does not land

[2.2] Optical density The inkjet ink composition of each of the above Examples and Comparative Examples was an inkjet printer (product name “PX-G930”, manufactured by Seiko Epson Corporation, nozzle resolution: 180 dpi). The inside of the head was filled. After filling, the ink-jet ink compositions of the above Examples and Comparative Examples were applied to a low-absorbency coated paper as a recording medium (Seiko Epson Corp., photo-low-absorbency coated paper (for pigments)). Application amount per unit area: 32.7 mg / cm ² was applied under the condition of solid coating to obtain a recorded matter.

For the two obtained recordings, the printed part was measured at three points with Spectrolino (manufactured by GretagMacbeth), the average value was obtained as the optical density, and evaluated according to the following criteria.
A: The optical density is 1.75 or more.
B: The optical density is 1.70 or more and less than 1.75.
C: The optical density is less than 1.70.

[2.3] Abrasion Resistance Regarding the recorded materials of each Example and Comparative Example manufactured in [2.2] above, the printed material that has passed for 1 hour after the solid coating is printed on the back side of the same paper as the printed material. The degree of transfer and transfer was visually observed, and the abrasion resistance was evaluated according to the following criteria.
A: Transfer is not recognized at all.
B: Slight transfer is observed.
C: Transcription is clearly recognized.
These results are shown in Table 4.

As is clear from Table 4, satisfactory results were obtained with the present invention, whereas satisfactory results were not obtained with the comparative example.
Moreover, the same tendency was confirmed as a result of performing the above-mentioned optical density test and the abrasion resistance test using the inkjet ink compositions of Examples and Comparative Examples on Photolag (manufactured by Hanemura). On the other hand, when the ink composition of Example 1 and the ink composition of Comparative Example 8 were recorded on plain paper XeroxP (Fuji Xerox Co., Ltd.), the effect of improving the optical density was not obtained.

Claims (10)

An inkjet ink composition recorded on a low-absorbency coated paper,
A self-dispersing pigment, resin particles, and wax particles,
The glass transition point of the resin material constituting the resin particles is −150 ° C. or more and 10 ° C. or less,
An inkjet ink composition, wherein the wax particles have an average particle size of 100 nm to 250 nm.   The inkjet ink composition according to claim 1, wherein the resin particles are composed of a styrene-acrylic copolymer.   The inkjet ink composition according to claim 1 or 2, wherein an average particle diameter of the resin particles is 180 nm or more and 250 nm or less.   The inkjet ink composition according to any one of claims 1 to 3, wherein the wax constituting the wax particles has a melting point of 60C or higher and 140C or lower. 5. The relationship of X _R > X _W is satisfied, where X _R [mass%] is the resin particle content and X _W [mass%] is the wax particle content. The inkjet ink composition according to item.   The ink-jet ink composition according to any one of claims 1 to 5, wherein the sum of the content ratio of the resin particles and the content ratio of the wax particles is 1.0 mass% or more and 6.0 mass% or less.   Furthermore, the inkjet ink composition of any one of Claim 1 thru | or 6 which contains a pyrrolidone derivative.   The ink-jet ink composition according to any one of claims 1 to 7, further comprising an amine derivative.   The ink-jet ink composition according to any one of claims 1 to 8, further comprising 1,2-alkanediol and / or glycol ether having 4 to 6 carbon atoms.   A recording method comprising applying the inkjet ink composition according to any one of claims 1 to 9 to a low-absorbency coated paper.