JP6809116B2 - Manufacturing method of ink, ink for inkjet recording and printed matter - Google Patents

Description

The present invention relates to inks that can be used in the production of printed matter.

Inkjet printers are widely used in printing on plain paper in homes and offices.

On the other hand, in the industrial world, a method of printing on a packaging material or an advertising medium using an inkjet printer is being studied. Examples of the packaging material and advertising medium include ink-non-absorbable recording media made of resin films such as olefin resin films and polyethylene terephthalate resin films, and poor absorption of coated paper provided with a coated layer on their surfaces. Examples include sex recording media.

However, unlike the plain paper, the ink non-absorbent or poorly absorbable recording medium hardly absorbs the solvent contained in the ink. Therefore, the conventional ink used for printing on the plain paper is not ink-non-inked. Even if it is diverted to printing on an absorbent or poorly absorbent recording medium, it may not be possible to form a clear image.

Examples of inks that can be used for printing on the ink non-absorbent or poorly absorbable recording medium and that can reduce the environmental load caused by organic solvents and the like include pigments, alkali-soluble resins, wax emulsions, and basic inks. A water-based ink composition for inkjet containing a compound, an aqueous medium, and a surfactant, wherein the wax emulsion has an average particle size of 150 to 200 nm, and the solid content of the wax emulsion is aqueous. A water-based ink composition for inkjet, which is 0.5 to 4% by mass in the ink composition for inkjet and the surfactant is an acetylene diol-based surfactant, is known (see, for example, Patent Document 1).

However, when the ink composition is continuously printed on the ink non-absorbent or poorly absorbable recording medium to produce a printed matter, when the printed surface of the printed matter comes into contact with the back surface of another printed matter. In addition, there is a problem that the ink is transferred from the printed surface to the back surface. Printed matter having this problem is generally considered to have insufficient settability, and has been a major problem in the continuous production of advertising media and the like as described above.
Further, the printed matter obtained by printing the ink composition on a non-absorbent or poorly absorbent recording medium may not be sufficient in terms of wear resistance, so that the printed surface is continuously printed. When the back surface and the back surface are in contact with each other and scratched, problems such as peeling of the printed surface may occur.

The settability and abrasion resistance as described above have been considered to be problems to be solved particularly when a polyolefin film or a polyethylene film is used as an ink non-absorbent recording medium.

International Publication 2015/11164 Pamphlet

The problem to be solved by the present invention is that it is difficult to absorb the solvent contained in the ink, for example, it is excellent in settability to an ink non-absorbent or poorly absorbent recording medium such as various resin films and coated paper, and is wear resistant. The purpose of the present invention is to provide an ink capable of producing a printed matter having excellent properties.

The present invention relates to an ink containing a polyolefin (A), a compound (B) having a urea bond, an aqueous medium (C) and a coloring material (D), and an ink for inkjet printing.

Further, the present invention comprises a step of adjusting the ink to a viscosity of 3 mPa · s to 20 mPa · s and a surface tension of 20 mN / m to 40 mN / m [1], and an ink adjusted to the range of the viscosity and surface tension. The present invention relates to a method for producing a printed matter, which comprises a step [2] of discharging to the recording medium and a step [3] of drying at 50 ° C. to 100 ° C.

The ink of the present invention is difficult to absorb the solvent contained in the ink, for example, has excellent settability on a non-absorbent or poorly absorbent recording medium such as various resin films and coated paper, and has excellent wear resistance. Excellent printed matter can be used in production.

The ink of the present invention is characterized by containing a polyolefin (A), a compound (B) having a urea bond, an aqueous medium (C) and a coloring material (D). The polyolefin (A), the compound (B) and the coloring material (D) are preferably present in a state of being dissolved or dispersed in an aqueous medium (C) which is a solvent.

(Polyolefin (A))
The polyolefin (A) imparts excellent wear resistance and settability to a printed matter obtained by printing the ink of the present invention on the ink non-absorbent or poorly absorbable recording medium.

As the polyolefin (A), a polymer or copolymer of a monomer containing an olefin-based monomer as a main component is used. As the olefin-based monomer, for example, α-olefins such as ethylene, propylene, butene, hexene, methylbutene, methylpentene and methylhexene, cyclic olefins such as norbonene and the like can be used.

Oxidized polyolefin can also be used as the polyolefin (A).

As the oxidized polyolefin, for example, a polyolefin in which an oxygen atom is introduced into the molecule by thermal decomposition or chemical decomposition using an acid or an alkaline component can be used. The oxygen atom constitutes, for example, a polar carboxyl group or the like.

As the polyolefin (A), those having a melting point of 90 ° C. or higher and 200 ° C. or lower are preferably used, and those having a melting point of 120 ° C. or higher and lower than 160 ° C. are used for even better settability and polishing resistance. It is more preferable for forming a printed matter having abrasion resistance. The melting point of the polyolefin (A) refers to a value measured by a melting point measuring device conforming to JIS K 0064.

As described above, the polyolefin (A) preferably exists in a state of being dissolved or dispersed in a solvent such as an aqueous medium (C), and is in a state of an emulsion dispersed in a solvent such as an aqueous medium (C). Is more preferable.

In that case, the polyolefin (A) particles formed by the polyolefin (A) preferably have an average particle diameter of 10 nm to 200 nm, and 30 nm to 150 nm, for example, when printing by an inkjet recording method. It is more preferable to achieve both good ejection properties and good settability after printing. The average particle size of the polyolefin (A) is a value measured by a dynamic light scattering method using a Microtrack UPA particle size distribution meter manufactured by Nikkiso Co., Ltd.

The content of the polyolefin (A) is not particularly limited, but it can form a printed matter having even better wear resistance, and can achieve the ejection stability required when the ink of the present invention is ejected by an inkjet method. In order to obtain an excellent ink, it is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 6% by mass, based on the total amount of the ink.

(Compound (B) having a urea bond)
As the ink of the present invention, the compound (B) having a urea bond is used in combination with the polyolefin (A). By using the compound (B) in combination with the polyolefin (A), the printed matter obtained by printing the ink of the present invention on the ink non-absorbent or poorly absorbable recording medium has excellent wear resistance. It is possible to impart settability.

As the compound (B) having a urea bond, urea or a urea derivative can be used.

As the urea derivative, for example, ethylene urea, propylene urea, diethyl urea, thiourea, N, N-dimethylurea, hydroxyethylurea, hydroxybutylurea, ethylenethiourea, diethylthiourea and the like are used alone or in combination of two or more. be able to.

Among them, it is particularly preferable to use urea, ethylene urea or 2-hydroxyethyl urea as the compound (B) in order to form a printed image having even more excellent wear resistance and settability. ..

The content of the compound (B) makes it possible to form a printed matter having even more excellent wear resistance, and is excellent in ejection stability and settability required when the ink of the present invention is ejected by an inkjet method. In order to obtain the ink, it is preferably 1% by mass to 20% by mass, more preferably 2% by mass to 15% by mass, and 3% by mass to 10% by mass with respect to the total amount of the ink. Is even more preferable.

The polyolefin (A) and the compound (B) are preferably used in a mass ratio [polyolefin (A) / compound (B)] of 1/6 to 6/1, preferably 1/5. It is more preferable to use the ink in the range of about 1/1 in order to exhibit the wear resistance of the ink.

Further, since the urea and the urea derivative have a high moisturizing function and function as a wetting agent, it is possible to prevent the ink from drying and solidifying in the vicinity of the nozzle of the printer and to secure the excellent ejection property of the ink. On the other hand, urea and urea derivatives having moisturizing properties easily release water when heated, so that they are transferred to the recording medium in the heating step after printing the ink of the present invention on the ink non-absorbent or poorly absorbable recording medium. It is easy to set (easy to dry), and printed matter can be formed quickly.

(Aqueous medium (C))
The ink of the present invention uses an ink containing an aqueous medium (C) as a solvent.

As the aqueous medium (C), water can be used alone, or a mixed solvent of water and a water-soluble organic solvent described later can be used.

Specifically, as the water, pure water such as ion-exchanged water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used.

Examples of the water-soluble organic solvent include ketones such as acetone, methyl ethyl ketone, methyl butyl ketone, and methyl isobutyl ketone; methanol, ethanol, 2-propanol, 2-methyl-1-propanol, 1-butanol, 2-methoxy. Alcohols such as ethanol; ethers such as tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane; dimethylformamide, N-methylpyrrolidone, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene Glycos such as glycols and polypropylene glycols; diols such as butanediol, pentanediol, hexanediol and similar diols; glycol esters such as propylene glycol laurate; diethylene glycol monoethyl, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, Glycol ethers such as cellosolves containing propylene glycol ethers, dipropylene glycol ethers, and triethylene glycol ethers; butyl alcohols such as methanol, ethanol, isopropyl alcohol, 1-propanol, 2-propanol, 1-butanol and 2-butanol. , Pentyl alcohols, and alcohols such as alcohols of the same family; sulfolanes; lactones such as γ-butyrolactone; lactams such as N- (2-hydroxyethyl) pyrrolidone, etc., alone or in combination of two or more. Can be done.

In addition to the above-mentioned water-soluble organic solvents, the water-soluble organic solvent has a boiling point of 100 ° C. or higher and 200 ° C. or lower and a vapor pressure of 0.5 hPa or higher at 20 ° C. in order to improve the quick-drying property of the ink. A sex organic solvent can be used.

Examples of the water-soluble organic solvent having a boiling point and vapor pressure in the above range include 3-methoxy-1-butanol, 3-methyl-3-methoxy-1-butanol, 3-methoxy-3-methyl-1-butyl acetate, and the like. Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol-t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl Examples thereof include ether, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, 4-methoxy-4-methyl-2-pentanone, ethyl lactate, and the like. The above combinations can be used.

Among the water-soluble organic solvents, HSP (Hansen solubility) is used to maintain good dispersion stability of the ink and to suppress deterioration of the ink ejection nozzle provided in the inkjet device due to the influence of the solvent contained in the ink. It is preferable to use a water-soluble organic solvent such that the hydrogen bond term δ _H of the parameter) is in the range of 6 to 20.

Specific examples of the water-soluble organic solvent having the hydrogen bond term of HSP in the above range include 3-methoxy-1-butanol, 3-methyl-3-methoxy-1-butanol, ethylene glycol monomethyl ether, and ethylene glycol mono. Ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol-t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monopropyl ether are preferable, and more preferably 3. -Methoxy-1-butanol and 3-methyl-3-methoxy-1-butanol.

As the aqueous medium (C), glycerin, diglycerin and / or derivatives thereof are organic solvents such as glycerin, diglycerin, polyglycerin, and diglycerin fatty acid in order to ensure the ejection stability of the ink during inkjet recording. Esters, polyoxypropylene (n) polyglyceryl ether represented by the general formula (1), polyoxyethylene (n) polyglyceryl ether represented by the general formula (2), and the like can be used. Two or more of these may be used at the same time. In the present invention, it is particularly preferable to select glycerin and polyoxypropylene (n) polyglyceryl ether having n = 8 to 15.

In the general formula (1) and the general formula (2), m, n, o and p each independently represent an integer of 1 to 10.

The blending amount of the aqueous medium (C) is preferably 1% by mass to 30% by mass, and 5% by mass to 25% by mass with respect to the total amount of the ink, which is excellent in settability and ejected by an inkjet method. It is more preferable because it has good ejection properties required in some cases and can be used for producing clear printed matter.

(Color material (D))
As the coloring material (D) used in the present invention, known and commonly used pigments, dyes and the like can be used. Among them, as the color material (D), it is preferable to use a pigment in producing a printed matter having excellent weather resistance and the like. Further, as the coloring material (D), a coloring agent in which the pigment is coated with a resin can also be used.

The pigment is not particularly limited, and organic pigments or inorganic pigments usually used in water-based gravure inks and water-based inkjet recording inks can be used.

Further, as the pigment, either an unacidified treated pigment or an acidic treated pigment can be used.

As the inorganic pigment, for example, iron oxide, carbon black produced by a method such as a contact method, a furnace method or a thermal method can be used.

Examples of the organic pigment include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, thioindigo pigments, isoindolinone pigments, quinofuralon pigments, etc.), lake pigments (for example, basic dye type chelates, acidic dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used.

Among the pigments, carbon black that can be used for black ink is No. 1 manufactured by Mitsubishi Chemical Corporation. 2300, No. 2200B, No. 900, No. 960, No. 980, No. 33, No. 40, No, 45, No. 45L, No. 52, HCF88, MA7, MA8, MA100, etc., Colombian Raven5750, Raven5250, Raven5000, Raven3500, Raven1255, Raven700, etc., Cabot Legal 400R, Regal 330R, Regal 660R, Mogul 660R, Mogul , Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc., Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, V, 1400U, Special Black 6, 5, 4, 4, 4A, NIPEX150, NIPEX160, NIPEX170, NIPEX180 and the like can be used.

Specific examples of pigments that can be used in yellow ink include C.I. I. Pigment Yellow 1, 2, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 120, 128, 129, 138, 150, 151, 154, 155, 174, 180, 185 and the like can be mentioned.

Specific examples of pigments that can be used in magenta ink include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 122, 123, 146, 168, 176, 184, 185, 202, 209, 269, 282 Etc., C.I. I. Pigment Violet 19 and the like.

Specific examples of pigments that can be used for cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 3, 15: 4, 16, 22, 60, 63, 66 and the like.

Specific examples of pigments that can be used for white ink include silica salts such as sulfates of alkaline earth metals, carbonates, fine powder silicic acid, synthetic silicates, calcium silicate, alumina, and alumina hydrates. Examples include titanium oxide, zinc oxide, talc, clay and the like. These may be surface-treated.

In order for the pigment to be stably present in the ink, it is preferable to take measures to disperse the pigment well in the aqueous medium (C).

As the means, for example, (i) a method of dispersing a pigment together with a pigment dispersant in an aqueous medium (C) by a dispersion method described later (ii) a dispersibility-imparting group (hydrophilic functional group and / or) on the surface of the pigment. Examples thereof include a method of dispersing and / or dissolving a self-dispersing pigment in which the salt) is directly or indirectly bonded via an alkyl group, an alkyl ether group, an aryl group or the like in an aqueous medium (C).

As the self-dispersion pigment, for example, a pigment obtained by subjecting the pigment to a physical treatment or a chemical treatment and binding (grafting) an active species having a dispersibility-imparting group or a dispersibility-imparting group to the surface of the pigment is used. be able to. The self-dispersing pigment is, for example, vacuum plasma treatment, oxidation treatment with hypohalous acid and / or hypohalite, oxidation treatment with ozone, or a wet oxidation method in which the pigment surface is oxidized with an oxidizing agent in water. Alternatively, it can be produced by a method in which a carboxyl group is bonded via a phenyl group by binding p-aminobenzoic acid to the surface of the pigment.

Since the water-based ink containing the self-dispersing pigment does not need to contain the pigment dispersant, there is almost no foaming or the like caused by the pigment dispersant, and it is easy to prepare an ink having excellent ejection stability. In addition, the water-based ink containing the self-dispersing pigment is easy to handle, and since a large increase in viscosity due to the pigment dispersant is suppressed, it is possible to contain a larger amount of pigment, and a printed matter having a high printing density can be produced. Can be used for.

Commercially available products can also be used as the self-dispersing pigments, and such commercially available products include Microjet CW-1 (trade name: manufactured by Orient Chemical Industry Co., Ltd.), CAB-O-JET200, Examples include CAB-O-JET300 (trade name; manufactured by Cabot).

The color material (D) is preferably used in the range of 1% by mass to 20% by mass with respect to the total amount of the ink, and is preferably used in the range of 2% by mass to 10% by mass in the ink. It is preferable for further improving the dispersion stability of the coloring material (D) such as the pigment.

(Pigment dispersant)
The pigment dispersant can be preferably used when a pigment is used as the coloring material (D).

Examples of the pigment dispersant include acrylic resins such as polyvinyl alcohols, polyvinylpyrrolidones, and acrylic acid-acrylic acid ester copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, and styrene-methacrylic acid. Styrene-acrylic resin such as -acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-maleic acid copolymer A coalescence, a styrene-maleic anhydride copolymer, an aqueous resin of a vinylnaphthalene-acrylic acid copolymer, and a salt of the aqueous resin can be used. Examples of the pigment dispersant include Ajinomoto Fine-Techno Co., Ltd.'s Ajispar PB series, Big Chemie Japan's Co., Ltd. Disperbyk series, BASF's EFKA series, Japan Lubrizol Co., Ltd.'s SOLPERSE series, and Evonik's. TEGO series and the like can be used.

As the pigment dispersant, the polymer (E) described later is used in order to significantly reduce coarse particles and, as a result, to impart good ejection properties required when the ink of the present invention is ejected by an inkjet method. Is preferable.

As the polymer (E), a polymer having an anionic group can be used, and among them, a polymer (E) having a solubility in water of 0.1 g / 100 ml or less and having a basic compound of the anionic group is used. It is preferable to use a polymer having a number average molecular weight in the range of 1000 to 6000, which can form fine particles in water when the sum ratio is 100%.

The solubility of the polymer (E) in water was defined as follows. That is, 0.5 g of the polymer (E) having a particle size adjusted in the range of 250 μm to 90 μm using a sieve having a mesh size of 250 μm and 90 μm is sealed in a bag processed with a 400 mesh wire mesh, immersed in 50 ml of water, and immersed at 25 ° C. The mixture was gently stirred for 24 hours at a temperature. After soaking for 24 hours, the 400 mesh wire mesh containing the polymer (E) was dried in a dryer set at 110 ° C. for 2 hours. The change in weight of the 400 mesh wire mesh containing the polymer (E) before and after immersion in water was measured, and the solubility was calculated by the following formula.

Further, in the present invention, whether or not fine particles are formed in water when the neutralization rate by the basic compound of the anionic group is set to 100% was determined as follows.
(1) The acid value of the polymer (E) is measured in advance by an acid value measuring method based on the JIS test method K 0070-1992. Specifically, 0.5 g of the polymer (E) is dissolved in tetrahydrofuran and titrated with a 0.1 M potassium hydroxide alcohol solution using phenolphthalein as an indicator to determine the acid value.
(2) To 50 ml of water, 1 g of the polymer (E) is added, and then a 0.1 mol / L potassium hydroxide aqueous solution that only neutralizes the obtained acid value by 100% is added to achieve 100% neutralization.
(3) The 100% neutralized liquid was irradiated with ultrasonic waves at a temperature of 25 ° C. for 2 hours in an ultrasonic cleaner (SND Ultrasonic Cleaner US-102, 38 kHz self-excited oscillation). After that, leave it at room temperature for 24 hours.

After leaving it for 24 hours, the sample liquid sampled at a depth of 2 cm from the liquid surface is used as a dynamic light scattering type particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., dynamic light scattering type particle size measuring device "Micro". The presence of fine particles is confirmed by determining whether light scattering information due to fine particle formation can be obtained using a track particle size distribution meter UPA-ST150 ").

In order to further improve the stability of the fine particles formed by the polymer (E) used in the present invention in water, the particle size of the fine particles is preferably in the range of 5 nm to 1000 nm, preferably in the range of 7 nm to 700 nm. More preferably, it is preferably in the range of 10 nm to 500 nm. Further, the narrower the particle size distribution of the fine particles, the better the dispersion stability tends to be, but even when the particle size distribution is wide, an ink having better dispersion stability than the conventional one can be obtained. The particle size and particle size distribution are determined by the dynamic light scattering type particle size distribution measuring device (dynamic light scattering type particle size measuring device "Microtrack particle size distribution meter UPA" manufactured by Nikkiso Co., Ltd. -ST150 ") was used for measurement.

The neutralization rate of the polymer (E) used in the present invention was determined by the following formula.

The acid value of the polymer (E) was measured based on the JIS test method K0070-1992. Specifically, it was obtained by dissolving 0.5 g of a sample in tetrahydrofuran and titrating with a 0.1 M potassium hydroxide alcohol solution using phenolphthalein as an indicator.

(Polymer (E) number average molecular weight)
The polymer (E) preferably has a number average molecular weight in the range of 1000 to 6000, more preferably 1300 to 5000, and preferably 1500 to 4500 as a pigment in the aqueous medium (C). It is more preferable to obtain an ink having good dispersion stability of the color material (D), which can effectively suppress the aggregation of the color material (D) such as the above.

The number average molecular weight is a polystyrene-equivalent value measured by GPC (gel permeation chromatography), and specifically, a value measured under the following conditions.

(Measurement method of number average molecular weight (Mn))
It was measured by the gel permeation chromatography (GPC) method under the following conditions.

Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.

"TSKgel G5000" (7.8 mm I.D. x 30 cm) x 1 "TSKgel G4000" (7.8 mm I.D. x 30 cm) x 1 "TSKgel G3000" (7.8 mm ID x 30 cm) x 1 This "TSKgel G2000" (7.8 mm ID x 30 cm) x 1 Detector: RI (Differential Refractometer)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Injection amount: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: A calibration curve was prepared using the following standard polystyrene.

(Standard polystyrene)
"TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

(surface tension)
As the polymer (E), the surface tension of the aqueous resin dispersion containing the polymer (E) is preferably 30 dyn / cm or more, more preferably 40 dyn / cm or more, and 65 dyn / cm to 65 dyn / cm, which is close to the surface tension of water. It is particularly preferable to use one having a speed of 75 dyn / cm. The surface tension of the polymer solution was 100% neutralized by adding 1 g of the polymer (E) to water and then adding a 0.1 mol / L potassium hydroxide aqueous solution capable of 100% neutralizing the obtained acid value. It is a value measured about.

As the polymer (E), a polymer that is insoluble or sparingly soluble in water in an unneutralized state and forms fine particles in a 100% neutralized state can be used, and is a hydrophilic group. The polymer is not particularly limited as long as it is a polymer having a hydrophobic group in one molecule in addition to a certain anionic group.

Examples of such a polymer include a block polymer having a polymer block having a hydrophobic group and a polymer block having an anionic group. In the polymer (E), the number of anionic groups and the solubility in water are not necessarily specified by the acid value or the number of anionic groups at the time of polymer design, for example, a polymer having the same acid value. Even if they are present, those having a low molecular weight tend to have a high solubility in water, and those having a high molecular weight tend to have a low solubility in water. From this, in the present invention, the polymer (E) is specified by its solubility in water.

The polymer (E) may be a homopolymer, but is preferably a copolymer, and may be a random polymer, a block polymer, or an alternating polymer, and is particularly a block polymer. Is preferable. The polymer may be a branched polymer, but is preferably a linear polymer.

Further, the polymer (E) is preferably a vinyl polymer from the viewpoint of design freedom, and as a method for producing a vinyl polymer having the desired molecular weight and solubility characteristics in the present invention, living radical polymerization and living cationic polymerization are used. , It is preferable to produce by using "living polymerization" such as living anionic polymerization.

Among them, the polymer (E) is preferably a vinyl polymer produced by using a (meth) acrylate monomer as one of the raw materials, and as a method for producing such a vinyl polymer, living radical polymerization and living anionic polymerization are used. Is preferable, and living anionic polymerization is preferable from the viewpoint of the molecular weight of the block polymer and the more precise design of each segment.

(The polymer (E) produced by living anionic polymerization)
The polymer (E) produced by living anionic polymerization is specifically a polymer represented by the general formula (3).

In the general formula (3), A ¹ represents an organic lithium initiator residue, A ² represents a polymer block of a monomer having an aromatic ring or a heterocycle, and A ³ represents a polymer block containing an anionic group, n. Represents an integer of 1-5 and B represents an aromatic or alkyl group.

In general formula (3), A ¹ represents an organolithium initiator residue. Specific examples of organolithium initiators include methyllithium, ethyllithium, propyllithium, butyllithium (n-butyllithium, sec-butyllithium, iso-butyllithium, tert-butyllithium, etc.), pentyllithium, hexyllithium, etc. Alkyllithium such as methoxymethyllithium and etoshikimethyllithium; phenylalkylenelithium such as benzyllithium, α-methylstyryllithium, 1,1-diphenyl-3-methylpentyllithium, 1,1-diphenylhexyllithium, phenylethyllithium Alkenyl lithium such as vinyl lithium, allyl lithium, propenyl lithium, butenyl lithium; alkynyl lithium such as ethynyl lithium, butynyl lithium, pentynyl lithium, hexynyl lithium; aryl lithium such as phenyllithium, naphthyllithium; 2-thienyl Heterocyclic lithium such as lithium, 4-pyridyllithium and 2-quinolyllithium; alkyllithium-magnesium complexes such as tri (n-butyl) magnesium lithium and trimethylmagnesium lithium can be mentioned.

In the organolithium initiator, the bond between the organic group and lithium is cleaved to generate an active terminal on the organic group side, and polymerization is started from there. Therefore, an organic group derived from organolithium is bonded to the terminal of the obtained polymer. In the present invention, the organic lithium-derived organic group bonded to the polymer terminal is referred to as an organolithium initiator residue. For example, in the case of a polymer using methyllithium as an initiator, the organolithium initiator acid group becomes a methyl group, and in the case of a polymer using butyllithium as an initiator, the organolithium initiator acid group becomes a butyl group.

In the general formula (3), A ² represents a polymer block having a hydrophobic group. A ² is another object to balance balance described above moderate solubility, it is preferably a high adsorption to the pigment group when in contact with the pigment, from the viewpoints, A ² is an aromatic ring or It is preferably a polymer block of a monomer having a heterocycle.
The polymer block of a monomer having an aromatic ring or a heterocycle is specifically obtained by homopolymerizing or copolymerizing a monomer having an aromatic ring such as a styrene-based monomer or a monomer having a heterocycle such as a vinylpyridine monomer. The resulting homopolymer or copolymer polymer block.

Examples of the monomer having an aromatic ring include styrene, p-tert-butyldimethylsiloxystyrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, p-tert-butoxystyrene, m-tert-butoxystyrene, and the like. Styrene-based monomers such as p-tert- (1-ethoxymethyl) styrene, m-chlorostyrene, p-chlorostyrene, p-fluorostyrene, α-methylstyrene, p-methyl-α-methylstyrene, and vinylnaphthalene. , Vinyl anthracene, etc.

Examples of the monomer having a heterocycle include vinylpyridine-based monomers such as 2-vinylpyridine and 4-vinylpyridine. These monomers can be used alone or in admixture of two or more.

In the general formula ^(3), A 3 represents a polymer block containing an anionic group. A ³ is another object to provide a described above moderate solubility, there is a purpose of imparting dispersion stability in water when a pigment dispersion.
Anionic groups in the polymer block A ^3, for example, carboxyl group, sulfonic acid group or phosphoric acid group. Of these, the carboxyl group is preferable because of its preparation and the abundance of monomer varieties that are easily available. Further, the two carboxyl groups may be an acid anhydride group obtained by dehydration condensation within or between molecules.

Method for introducing anionic groups of the A ³ is not particularly limited, for example, the case the anionic group is a carboxyl group, (meth) homopolymer obtained by copolymerizing a homopolymer or other monomers acrylic acid or It may be a polymer block (PB1) of a copolymer, or a homozygous obtained by homopolymerizing (meth) acrylate having a reproducible protective group as an anionic group by deprotection or copolymerizing with another monomer. The polymer or copolymer may be a polymer block (PB2) in which some or all of the protective groups reproducible to the anionic group are regenerated to the anionic group.

Incidentally, the A polymer block used in A ³ (meth) acrylic acid represents the general term for acrylic acid and methacrylic acid, and (meth) acrylate represents the general term for acrylate and methacrylate.

Specific examples of (meth) acrylic acid and (meth) acrylate include (meth) acrylic acid, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, iso-propyl (meth) acrylic acid, and (meth) acrylic acid. Allyl, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-amyl (meth) acrylate, (meth) Iso-amyl acrylate, n-hexyl (meth) acrylate, n-octyl acrylate, 2-ethylhexyl (meth) acrylate, n-lauryl (meth) acrylate, n-tridecyl (meth) acrylate , N-stearyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-tert-butylcyclohexyl (meth) acrylate, isobornyl (meth) acrylate, Tricyclodecanyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, adamantyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfurfryl (meth) acrylate, 2 (meth) acrylate -Methoxyethyl, 2-ethoxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, ( Pentafluoropropyl acrylate, (meth) octafluoropentyl acrylate, pentadecafluorooctyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, N, N-dimethyl (meth) acrylamide, (meth) Acryloylmorpholin, (meth) acrylonitrile, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polyethylene glycol-polybutylene glycol (meth) acrylate, polypropylene glycol-polybutylene glycol ( Meta) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, butoxypolyethylene glycol (meth) acrylate, octoxypolyethylene glycol (meth) acrylate, lauroxypolyethylene glycol Contains polyalkylene oxide groups such as (meth) acrylate, stearoxy polyethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, octoxypolyethylene glycol-polypropylene glycol (meth) acrylate. ) Acrylate and the like can be mentioned. These monomers can be used alone or in admixture of two or more.

In the living anionic polymerization method, when the monomer used is a monomer having a group having an active proton such as an anionic group, the active end of the living anionic polymer polymer immediately reacts with the group having these active protons and is deactivated. No polymer is available. Since it is difficult to polymerize a monomer having a group having an active proton as it is in living anionic polymerization, the group having an active proton is polymerized in a protected state, and then the protecting group is deprotected to have an active proton. It is preferable to regenerate the group.

For this reason, in the polymer block A ^3, it is preferable to use a monomer containing a (meth) acrylate having a renewable protecting group an anionic group by deprotection. By using the monomer, it is possible to prevent the above-mentioned inhibition of polymerization at the time of polymerization. Further, the anionic group protected by the protecting group can be regenerated into an anionic group by deprotecting after obtaining the block polymer.

For example, when the anionic group is a carboxyl group, the carboxyl group can be regenerated by esterifying the carboxyl group and deprotecting it by hydrolysis or the like as a subsequent step. In this case, the protective group that can be converted into a carboxyl group is preferably a group having an ester bond, and for example, a primary alkoxycarbonyl group such as a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, or an n-butoxycarbonyl group. Secondary alkoxycarbonyl groups such as isopropoxycarbonyl groups and sec-butoxycarbonyl groups; Tertiary alkoxycarbonyl groups such as t-butoxycarbonyl groups; Phenylalkoxycarbonyl groups such as benzyloxycarbonyl groups; ethoxyethylcarbonyl groups and the like Alkoxyalkylcarbonyl group of.

When the anionic group is a carboxyl group, the monomers that can be used include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and sec. -Butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate ) Acrylate), tridecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate), nonadecil (meth) acrylate, icosanyl (meth) ) Alkyl (meth) acrylate such as acrylate; phenylalkylene (meth) acrylate such as benzyl (meth) acrylate; alkoxyalkyl (meth) acrylate such as ethoxyethyl (meth) acrylate and the like. These (meth) acrylates can be used alone or in combination of two or more. Further, among these (meth) acrylates, t-butyl (meth) acrylate and benzyl (meth) acrylate are preferable because the conversion reaction to a carboxyl group is easy. Further, in consideration of industrial availability, t-butyl (meth) acrylate is more preferable.

In the general formula (3), B represents an aromatic group or an alkyl group having 1 to 10 carbon atoms. Further, n represents an integer of 1 to 5.

In the living anion polymerization method, when an attempt is made to directly polymerize a (meth) acrylate monomer to the active terminal of a styrene-based polymer having strong nucleophilicity, it may not be possible to polymerize due to a nucleophilic attack on the carbonyl carbon. Therefore, when the (meth) acrylate monomer is polymerized in A ¹ − A ² , a reaction modifier is used to adjust the nucleophile, and then the (meth) acrylate monomer is polymerized. B in the general formula (3) is a group derived from the reaction modifier. Specific examples of the reaction modifier include diphenylethylene, α-methylstyrene, p-methyl-α-methylstyrene and the like.

(Living anionic polymerization using a microreactor)
The living anion polymerization method can be carried out by a batch method as used in the conventional free radical polymerization by adjusting the reaction conditions, and a method of continuous polymerization by a microreactor can also be mentioned. In the microreactor, since the mixture of the polymerization initiator and the monomer is good, the reaction starts at the same time, the temperature is uniform, and the polymerization rate can be made uniform, so that the molecular weight distribution of the produced polymer can be narrowed. At the same time, since the growth end is stable, it becomes easy to produce a block copolymer in which both components of the block are not mixed. Moreover, since the controllability of the reaction temperature is good, it is easy to suppress side reactions.

A general method of living anionic polymerization using a microreactor will be described with reference to FIG. 1, which is a schematic diagram of the microreactor.
A T-shaped micromixer M1 (FIG. 7) provided with a flow path capable of mixing a plurality of liquids from tube reactors P1 and P2 (7 and 8 in FIG. 1) for the first monomer and the polymerization initiator for initiating polymerization, respectively. Introduced into 1) of 1), the first monomer is subjected to living anionic polymerization in the T-shaped micromixer M1 to form the first polymer (step 1).

Next, the obtained first polymer was moved to a T-shaped micromixer M2 (2 in FIG. 1), and the growth end of the obtained polymer was transferred to the tube reactor P3 (FIG. 1) in the mixer M2. The reaction is regulated by trapping with the reaction modifier introduced from the middle 9) (step 2).
At this time, the number of n in the general formula (3) can be controlled by the type and amount of the reaction modifier.

Next, the first polymer whose reaction was adjusted in the T-shaped micromixer M2 was moved to the T-shaped micromixer M3 (3 in FIG. 1), and in the mixer M3, from the tube reactor P4. Living anionic polymerization is continuously carried out between the introduced second monomer and the first polymer whose reaction has been adjusted (step 3).

Then, the reaction is quenched with a compound having an active proton such as methanol to produce a block copolymer.

When the polymer (E) represented by the general formula (3) of the present invention is produced in the microreactor, a monomer having an aromatic ring or a heterocycle is used as the first monomer, and an organic is used as the initiator. by reacting the lithium initiator, an organic group at one terminal of the polymer block (the polymer block a ² monomers are organolithium initiator residues of the a ¹ having an aromatic ring or a heterocyclic ring of the a ² (Combined) is obtained.
Next, after adjusting the reactivity of the growth terminal using a reaction modifier, a monomer containing a (meth) acrylate having a renewable protecting group on the anionic group is reacted as the second monomer to cause a polymer block. To get.

Thereafter, by reproducing the anionic group by deprotection reaction such as hydrolysis, polymer blocks containing the A ³ i.e. anionic groups are obtained.

A method for regenerating the ester bond of a reproducible protecting group on the anionic group into an anionic group by a deprotection reaction such as hydrolysis will be described in detail.

The hydrolysis reaction of an ester bond proceeds under both acidic and basic conditions, but the conditions differ slightly depending on the group having the ester bond. For example, when the group having an ester bond is a primary alkoxycarbonyl group such as a methoxycarbonyl group or a secondary alkoxycarbonyl group such as an isopropoxycarbonyl group, a carboxyl group can be obtained by hydrolysis under basic conditions. be able to. At this time, examples of the basic compound under the basic conditions include metal hydroxides such as sodium hydroxide and potassium hydroxide.

When the group having an ester bond is a tertiary alkoxycarbonyl group such as a t-butoxycarbonyl group, a carboxyl group can be obtained by hydrolysis under acidic conditions. At this time, examples of the acidic compound under acidic conditions include mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid; breathed acids such as trifluoroacetic acid; and Lewis acids such as trimethylsilyl trifurate. The reaction conditions for hydrolysis under acidic conditions of the t-butoxycarbonyl group are disclosed, for example, in "The Chemical Society of Japan, 5th Edition, Experimental Chemistry Course 16 Synthesis of Organic Compounds IV".

Further, as a method for converting the t-butoxycarbonyl group into a carboxyl group, a method using a cation exchange resin instead of the above acid can also be mentioned. Examples of the cation exchange resin, e.g., a carboxyl group (-COOH) in the side chain of the polymer chain, resins having a sulfo group (-SO 3 _H) acid groups and the like. Among these, a strongly acidic cation exchange resin having a sulfo group in the side chain of the resin is preferable because the reaction can proceed quickly. Examples of commercially available products of the cation exchange resin that can be used in the present invention include the strongly acidic cation exchange resin "Amberlite" manufactured by Organo Corporation. Since the amount of this cation exchange resin used can be effectively hydrolyzed, it is preferably in the range of 5 parts by mass to 200 parts by mass with respect to 100 parts by mass of the polymer represented by the general formula (3), and is 10 parts by mass. A range of ~ 100 parts by mass is more preferable.

When the group having an ester bond is a phenylalkoxycarbonyl group such as a benzyloxycarbonyl group, it can be converted to a carboxyl group by performing a hydrogenation reduction reaction. At this time, as a reaction condition, the phenylalkoxycarbonyl group can be quantitatively regenerated into a carboxyl group by reacting with hydrogen gas as a reducing agent in the presence of a palladium catalyst such as palladium acetate at room temperature.

As described above, since the reaction conditions during the conversion of the type of group to the carboxyl group are different with, for example, t- butyl as a raw material of A ³ (meth) acrylate and n- butyl (meth) acrylate with an ester bond The polymer obtained by copolymerization will have a t-butoxycarbonyl group and an n-butoxycarbonyl group. Here, under acidic conditions in which the t-butoxycarbonyl group is hydrolyzed, the n-butoxycarbonyl group is not hydrolyzed, so that only the t-butoxycarbonyl group can be selectively hydrolyzed to deprotect the carboxyl group. Will be. Therefore, it is possible to the acid value of the adjustment of the hydrophilic block (A ³⁾ by appropriately selecting a monomer containing a (meth) acrylate having a renewable protecting group an anionic group which is a raw material monomer of A ^3.

Further, in the polymer (E) represented by the general formula (3), when the polymer block (A ² ) and the polymer block (A ³ ) are clearly separated, the obtained aqueous pigment dispersion is stable. It is advantageous in sex. The molar ratio A ² : A ³ of the polymer block (A ² ) to the polymer block (A ³ ) is preferably in the range of 100: 10 to 100: 500, and A ² : A ³ = 100: 10 to 100 :. The value of 450 is used in order to obtain an ink capable of producing a printed matter which can maintain the good ejection property required when ejecting ink by, for example, an inkjet method, and which is further excellent in color development. More preferred.

Further, in the polymer (E) represented by the general formula (3), the number of monomers having an aromatic ring or a heterocycle constituting the polymer block (A ² ) is preferably in the range of 5 to 40, and is in the range of 6 to 30. Is still preferable, and the range of 7 to 25 is most preferable. The number of anionic groups constituting the polymer block ^{(A 3)} is preferably in the range of 3 to 20, still preferably in the range of 4 to 17, and most preferably in the range of 5 to 15.
The molar ratio of the polymer block (A ² ) to the polymer block (A ³ ) A ² : A ³ is composed of the number of moles having an aromatic ring or a heterocycle constituting the polymer block (A ² ) and (A ³ ). When expressed by the molar ratio of the number of moles of the anionic group to be used, 100: 7.5 to 100: 400 is preferable.

The acid value of the polymer (E) represented by the general formula (3) is preferably 40 mgKOH / g to 400 mgKOH / g, more preferably 40 mgKOH / g to 300 mgKOH / g, and 40 mgKOH / g to 190 mgKOH / g. It is more preferable to obtain an ink capable of producing a printed matter which can maintain the good ejection property required when ejecting ink by, for example, an inkjet method and has further excellent wear resistance and the like. ..

The acid value of the polymer in the present invention was determined by the same acid value measuring method as the method for measuring the fine particles of the polymer (E).

(Neutralizer basic compound)
In the inkjet recording ink of the present invention, it is preferable that the anionic group of the polymer (E) is neutralized.

As the basic compound for neutralizing the anionic group of the polymer (E), any known and commonly used compound can be used, for example, inorganic basic compounds such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. Substances and organic basic compounds such as ammonia, triethylamine and alkanolamine can be used.
In the present invention, the neutralization amount of the polymer (E) present in the aqueous pigment dispersion does not need to be 100% neutralized with respect to the acid value of the polymer. Specifically, the polymer (E) is preferably neutralized so that the neutralization rate is 20% to 200%, more preferably 80% to 150%.

(Other additives)
In addition to the above components, the ink of the present invention contains a binder resin other than the polyolefin (A), a wetting agent (drying inhibitor), a penetrant, a preservative, a viscosity regulator, a pH adjuster, and chelating, if necessary. Those containing other additives such as agents, plasticizers, antioxidants, and UV absorbers can be used.

Examples of the other binder resin include polyvinyl alcohol, gelatin, polyethylene oxide, polyvinylpyrrolidone, acrylic resin, urethane resin, dextran, dextrin, colorginan (κ, ι, λ, etc.), agar, purulan, and water-soluble polyvinyl butyral. , Hydroxyethyl cellulose, carboxymethyl cellulose and the like can be used alone or in combination of several kinds. Of these, it is preferable to use an acrylic resin, and it is preferable to use an acrylic resin having an amide group in order to obtain an ink having excellent redispersibility.

As the acrylic resin, a polymer of an acrylic monomer having an amide group and, if necessary, other monomers can be used.

Examples of the acrylic monomer having an amide group include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, and N-methylol (meth). Acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, Examples thereof include N-dimethylaminopropyl (meth) acrylamide, diacetone (meth) acrylamide, and hydroxyethyl (meth) acrylamide.

The acrylic monomer having an amide group is preferably used in a range of 5% by mass or less with respect to the total amount of the monomers used in the production of the acrylic resin. Specifically, the acrylic monomer having an amide group is preferably used in an amount of 0.5% by mass to 5% by mass, and 0.5% by mass to 4% by mass, based on the total amount of the monomer. It is more preferable that the content is 1.5% by mass to 3% by mass because the balance between hydrophilicity and hydrophobicity is good, so that the dispersion stability is excellent and the ink redispersibility (for example, in the inkjet method). In the case of ejecting ink, it is particularly preferable to obtain ink having excellent properties (property of preventing ink clogging at the nozzle).

Examples of other monomers that can be used in combination with the acrylic monomer having an amide group include (meth) acrylic acid, an alkali metal salt thereof, methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth). (Meta) acrylic acid ester-based monomers such as meta) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, acrylic amide, N, N-dimethyl (meth) acrylic Examples thereof include acrylic monomers having an amide group such as amide, and acrylic monomers such as (meth) acrylonitrile, 2-dimethylaminoethyl (meth) acrylate, and glycidyl (meth) acrylate.

Further, as the other monomer, a monomer having an ethylenically unsaturated group capable of polymerizing with an acrylic monomer can be used, for example, styrene, α-methylstyrene, p-tert. -Aromatic vinyl compounds such as butyl styrene, vinyl naphthalene and vinyl anthracene, vinyl sulfonic acid compounds such as vinyl sulfonic acid and styrene sulfonic acid, vinyl pyridine compounds such as 2-vinyl pyridine, 4-vinyl pyridine and naphthyl vinyl pyridine, vinyl. Triethoxysilane, vinyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltri Examples thereof include ethoxysilane and 3-acryloxypropyltrimethoxysilane.

As the other monomer, it is preferable to use a monomer having an aromatic group such as styrene or benzyl (meth) acrylate from the viewpoint of affinity with the pigment.

Further, in order to further improve the adhesiveness of the ink to the ink non-absorbent or poorly absorbable recording medium, the acrylic resin is tetrahydrofuran, which is a developing solvent at the time of molecular weight measurement by gel permeation chromatography. It may be used that contains a component that is insoluble in and whose molecular weight is difficult to measure.

The component insoluble in tetrahydrofuran, which is a developing solvent at the time of measuring the molecular weight of the acrylic resin by gel permeation chromatography, can be regarded as having a number average molecular weight of at least 100,000 and a mass average molecular weight of at least 500,000.

The acrylic resin is in a dispersed state in the aqueous medium (C), and various dispersion forms can be mentioned. For example, an aqueous dispersion containing an acrylic resin, an emulsifier, and an aqueous medium (C) is used. Can be done.

The average particle size of the acrylic resin is not particularly limited, but it is preferable to use a small one in order to maintain good ejection properties required when ejecting ink by, for example, an inkjet method. The average particle size is preferably an average particle size in the range of 10 nm to 200 nm as measured by, for example, "Microtrac particle size analyzer" UPA-EX150 "manufactured by Nikkiso Co., Ltd."

The acrylic resin is preferably used in the range of 3% by mass to 15% by mass, more preferably in the range of 3% by mass to 12% by mass, and 3% by mass to 9% by mass, based on the total amount of the ink. It is particularly preferable to use the ink in the above range in order to obtain an ink capable of producing a high-gloss printed matter, which has good ejection properties required when ejecting ink by, for example, an inkjet method.

The wetting agent that can be used for the optional component can be added for the purpose of preventing the ink from drying. The content of the wetting agent in the ink is preferably 3% by mass to 50% by mass.

The wetting agent is not particularly limited, but one that is compatible with water and can prevent clogging of the head of an inkjet printer is preferable. For example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol having a molecular weight of 2000 or less is preferable. , Dipropylene glycol, tripropylene glycol, 1,3-propylene glycol, isopropylene glycol, isobutylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol , Mesoerythritol, pentaerythritol and the like.

Examples of the penetrant that can be used for the optional component include lower alcohols such as ethanol and isopropyl alcohol, ethylene oxide adducts of alkyl alcohols such as ethylene glycol hexyl ether and diethylene glycol butyl ether, and propylene oxide additions of alkyl alcohols such as propylene glycol propyl ether. Things etc. can be mentioned. The content of the penetrant is preferably 3% by mass or less, more preferably 1% by mass or less, and further preferably substantially not contained in the total amount of the ink.

The surfactant can be used to improve the leveling property of the ink by lowering the surface tension of the ink.

The surfactant is not particularly limited, and examples thereof include various anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, and the like. Sexual surfactants and nonionic surfactants are preferable.

Examples of anionic surfactants include alkylbenzene sulfonates, alkylphenyl sulfonates, alkylnaphthalene sulfonates, higher fatty acid salts, sulfate ester salts of higher fatty acid esters, sulfonates of higher fatty acid esters, and higher alcohol ethers. Sulfate ester salts and sulfonates, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, etc. Specific examples of these include dodecylbenzene sulfonate, isopropylnaphthalene sulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenylsulfonate, dibutylphenylphenol disulfonate and the like.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, and glycerin fatty acid ester. , Polyoxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, fatty acid alkylolamide, alkylalkanolamide, acetylene glycol, oxyethylene adduct of acetylene glycol, Polyethylene glycol polypropylene glycol block copolymer, etc. can be mentioned, among which polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid, etc. Esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkylolamides, acetylene glycols, oxyethylene adducts of acetylene glycol, polyethylene glycol polypropylene glycol block copolymers are preferred. Of these, acetylene glycol and an oxyethylene adduct of acetylene glycol are more preferable because they reduce the contact angle of the ink droplets with respect to the recording medium and obtain a good printed matter.

Other surfactants include silicone-based surfactants such as polysiloxane oxyethylene adducts; fluorine-based surfactants such as perfluoroalkyl carboxylic acid salts, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers. Agents; biosurfactants such as spicrysporic acid, ramnolipide, lysolecithin and the like can also be used.

These surfactants can be used alone or in combination of two or more. Further, considering the dissolution stability of the surfactant and the like, the HLB thereof is preferably in the range of 7 to 20.

The surfactant is preferably used in the range of 0.001% by mass to 2% by mass, more preferably 0.001% by mass to 1.5% by mass, based on the total mass of the ink. It is more preferable to use it in the range of 0.01% by mass to 1% by mass in order to obtain an ink capable of producing a printed matter having even better settability and abrasion resistance.

(Ink manufacturing method)
The ink of the present invention can be produced, for example, by mixing polyolefin (A), compound (B) having a urea bond, an aqueous medium (C), a coloring material (D), and if necessary, the above-mentioned optional components. ..

At the time of the mixing, for example, a disperser such as a bead mill, an ultrasonic homogenizer, a high-pressure homogenizer, a paint shaker, a ball mill, a roll mill, a sand mill, a sand grinder, a dyno mill, a dispermat, an SC mill, or a nanomizer can be used.

As a method for producing the ink, more specifically, the polyolefin (A), the compound (B) having a urea bond, the aqueous medium (C), the coloring material (D), and if necessary, the optional components are collectively combined. A method of producing the mixture by mixing the mixture and stirring the mixture can be mentioned.

Further, as a method for producing an ink different from the above, for example, <1> a pigment dispersant such as the polymer (E), a coloring material (D) such as the pigment, and a solvent or the like are mixed if necessary. Thus, in the step of producing the color material dispersion a containing the color material (D) at a high concentration, <2> the composition b by mixing the compound (B) having a urea bond with a solvent if necessary. <3> A step of producing a composition c containing the polyolefin (A) and the aqueous medium (C), and <4> the colorant dispersion a and the composition b. Examples thereof include a method of producing by passing through a step of mixing with the composition c.

It is preferable that the ink obtained by the above method is subjected to a centrifugation treatment or a filtration treatment as necessary in order to remove impurities mixed in the ink.

(Physical characteristics of ink)
The ink of the present invention has a viscosity at 32 ° C. of preferably 2.0 mPa · s or more, more preferably 3.0 mPa · s or more, and even more preferably 5.0 mPa · s or more. Further, from the viewpoint of improving the storage stability and ejection property of the ink, it is preferably 12 mPa · s or less, more preferably 9.0 mPa · s or less, and further preferably 7.0 mPa · s or less. If the ink has a viscosity in the above range, it is possible to maintain good ejection performance, for example, when ejecting the ink by an inkjet method.

The pH of the ink of the present invention improves the storage stability and ejection property of the ink, and improves the widening of the dot diameter, the print density, and the scratch resistance when printed on a non-absorbent or poorly absorbent recording medium. On top of that, it is preferably 7.0 or more, more preferably 7.5 or more, and even more preferably 8.0 or more. The upper limit of the pH of the ink suppresses deterioration of members (for example, ink ejection nozzle, ink flow path, etc.) constituting the ink coating or ejection device, and reduces the influence when the ink adheres to the skin. It is preferably 11.0 or less, more preferably 10.5 or less, and even more preferably 10.0 or less.

(recoding media)
The ink of the present invention does not have a recording medium having excellent ink absorbency such as copy paper (PPC paper) generally used in a copying machine, a recording medium having an ink absorption layer, and ink absorbability at all. It is possible to print on a non-absorbent recording medium or a poorly absorbent recording medium having low ink absorbency. In particular, the ink of the present invention can obtain a printed matter having excellent settability and abrasion resistance even when printed on a non-absorbent or poorly absorbent recording medium.

As the poorly absorbable recording medium, a recording medium having a water absorption amount of 10 g / m ² or less at a contact time of 100 msec between the recording medium and pure water can be used in combination with the ink of the present invention. , Which is preferable for obtaining a printed matter having even better wear resistance.

The amount of water absorbed was measured at a contact time of pure water of 100 ms under the conditions of 23 ° C. and 50% relative humidity using an automatic scanning liquid absorption meter (KM500win manufactured by Kumagai Riki Kogyo Co., Ltd.). The amount of transfer was measured and the amount of water absorbed was 100 msec. The measurement conditions are shown below.

[Spiral Model]
Contact Time: 0.010 to 1.0 (sec)
Pitch: 7 (mm)
Lence per sampling: 86.29 (degree)
Start Radius: 20 (mm)
End Radius: 60 (mm)
Min Contact Time: 10 (ms)
Max Contact Time: 1000 (ms)
Sampleing Pattern: 50
Number of sampling points: 19
[Square Head]
Slit Span: 1 (mm)
Wide: 5 (mm)

Examples of absorbent recording media include plain paper, cloth, cardboard, wood and the like. Further, an example of a recording medium having an absorption layer is an inkjet paper or the like, and a specific example thereof is PICTORICO Pro Photo Paper of PICTORICO Co., Ltd. or the like.

Art paper such as printing paper, coated paper, lightweight coated paper, and finely coated paper can be used as the poorly absorbent recording medium having low ink absorption. These poorly absorbent recording media are coated with a coating material on the surface of high-quality paper, neutral paper, etc., which is mainly composed of cellulose and is not surface-treated, and is provided with a coated layer. Oji Paper Co., Ltd. Finely coated paper such as "OK Everlight Coat" manufactured by Nippon Paper Co., Ltd. and "Aurora S" manufactured by Nippon Paper Co., Ltd., "OK Coat L" manufactured by Oji Paper Co., Ltd. and "Aurora L" manufactured by Nippon Paper Co., Ltd. Lightweight coated paper (A3) such as "Oji Paper Co., Ltd.""OK Top Coat + (basis weight 104.7 g / m ² , water absorption amount at contact time 100 msec) 4.9 g / M ² ) ”,“ Aurora Coated ”manufactured by Nippon Paper Co., Ltd., Finesse Gloss (manufactured by UPM, 115 g / m ² , water absorption 3.1 g / m ² ) and Fines Matt (115 g / m) ^2. Coated paper (A2, B2) such as water absorption 4.4 g / m ² ), art paper such as "OK Kanto +" manufactured by Oji Paper Co., Ltd. and "Tokuryo Art" manufactured by Mitsubishi Paper Co., Ltd. (A1) and the like can be mentioned.

As an example of a non-water-absorbent recording medium having no ink absorbency, for example, those used for packaging materials for foods and the like can be used, and known plastic films can be used. Specific examples include polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyolefin films such as polyethylene and polypropylene, polyamide films such as nylon, polystyrene films, polyvinyl alcohol films, polyvinyl chloride films, polycarbonate films, and polyacrylonitrile films. Examples include polylactic acid film. In particular, polyester film, polyolefin film, and polyamide film are preferable, and polyethylene terephthalate, polypropylene, and nylon are more preferable. Further, the above-mentioned film coated with polyvinylidene chloride or the like for imparting barrier properties may be used, or if necessary, a film laminated with a vapor-deposited layer of a metal such as aluminum or a metal oxide such as silica or alumina may be used in combination. You may.

The plastic film may be an unstretched film, but may be stretched in a uniaxial or biaxial direction. Further, the surface of the film may be untreated, but it is preferably subjected to various treatments for improving adhesiveness, such as corona discharge treatment, ozone treatment, low temperature plasma treatment, frame treatment, and glow discharge treatment.

The film thickness of the plastic film is appropriately changed depending on the application. For example, in the case of flexible packaging applications, the film thickness is 10 μm to 100 μm, assuming that it has flexibility, durability, and curl resistance. It is preferable to have. More preferably, it is 10 μm to 30 μm. Specific examples of this include Toyobo Co., Ltd.'s pipe wrench and Espet (both are registered trademarks).

Hereinafter, the present invention will be described in more detail by way of examples.

(Method for preparing polymer (E))
(Synthesis Example 1)
Buttyllithium (BuLi) as the polymerization initiator and styrene (St) as the first monomer were introduced from the tube reactors P1 and P2 in FIG. 1 into the T-shaped micromixer M1 in FIG. 1, and subjected to living anionic polymerization. A coalescence was formed.

Next, the obtained polymer was transferred to the T-shaped micromixer M2 in FIG. 1 through the tube reactor R1 in FIG. 1, and the growth end of the polymer was introduced from the tube reactor P3 in FIG. It was trapped with α-methylstyrene (α-MeSt)).

Next, the methacrylic acid tert-butyl ester (t-BMA) as a second monomer was introduced from the tube reactor P4 shown in FIG. 1 into the T-shaped micromixer M3, and the polymer was transferred through the tube reactor R2 in FIG. , A continuous living anionic polymerization reaction was carried out. Then, the reaction was quenched with methanol to produce a block copolymer (PA-1).

At this time, the reaction temperature was set to 24 ° C. by burying the entire microreactor in a constant temperature bath. In addition, the monomer and reaction modifier to be introduced into the microreactor are dissolved in tetrahydrofuran, and BuLi is a commercially available 2.6M hexane solution diluted with hexane, and depending on the dilution concentration and introduction rate, block copolymer (PA-1). ) Was adjusted. The molar ratios are shown in Table 1.

The obtained block copolymer (PA-1) is hydrolyzed by treating with a cation exchange resin, the reaction solution is distilled off under reduced pressure, and the obtained solid is pulverized to obtain a polymer (P-). The powder of 1) was obtained.

(Measuring method of polymer physical properties)
The physical characteristic values of the obtained polymer (P-1) were measured as follows.

(Method for measuring number average molecular weight (Mn) and weight average molecular weight (Mw))
It was measured by the gel permeation chromatography (GPC) method under the following conditions.

Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.

"TSKgel G5000" (7.8 mm I.D. x 30 cm) x 1 "TSKgel G4000" (7.8 mm I.D. x 30 cm) x 1 "TSKgel G3000" (7.8 mm ID x 30 cm) x 1 This "TSKgel G2000" (7.8 mm ID x 30 cm) x 1 Detector: RI (Differential Refractometer)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Injection amount: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: A calibration curve was prepared using the following standard polystyrene.

(Standard polystyrene)
"TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

(Measuring method of acid value)
The measurement was performed according to the JIS test method K 0070-1992. It was determined by dissolving 0.5 g of a sample in tetrahydrofuran and titrating with a 0.1 M potassium hydroxide alcohol solution using phenolphthalein as an indicator.

(Measurement method of solubility in water)
0.5 g of a polymer having a particle size adjusted in the range of 250 μm to 90 μm using a sieve with a mesh size of 250 μm and 90 μm is sealed in a bag processed with a 400 mesh wire mesh, immersed in 50 ml of water, and immersed in water at a temperature of 25 ° C. for 24 hours. It was gently stirred and left to stand. After soaking for 24 hours, the 400 mesh wire mesh containing the polymer was dried in a dryer set at 110 ° C. for 2 hours. The change in weight of the 400 mesh wire mesh containing the polymer before and after immersion in water was measured, and the solubility was calculated by the following formula.

(Method of determining fine particle formation in water and method of measuring average particle size (nm)))
(1) The acid value of the polymer was measured in advance by an acid value measuring method based on the JIS test method K 0070-1992. Specifically, 0.5 g of the polymer was dissolved in tetrahydrofuran and titrated with a 0.1 M potassium hydroxide alcohol solution using phenolphthalein as an indicator to determine the acid value.
(2) After adding 1 g of the polymer (E) to 50 ml of water, a 0.1 mol / L potassium hydroxide aqueous solution capable of 100% neutralizing the obtained acid value was added to make 100% neutralization.
(3) The 100% neutralized liquid was irradiated with ultrasonic waves at a temperature of 25 ° C. for 2 hours in an ultrasonic cleaner (SND Ultrasonic Cleaner US-102, 38 kHz self-excited oscillation). After that, it was left at room temperature for 24 hours.

After leaving it for 24 hours, the sample liquid sampled at a depth of 2 cm from the liquid surface is used as a dynamic light scattering type particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., dynamic light scattering type particle size measuring device "Micro". By determining whether light scattering information due to fine particle formation can be obtained using a track particle size distribution meter UPA-ST150 "), it was confirmed whether or not the fine particles were present, and the average particle size thereof was measured.

(Measuring method of surface tension)
The surface tension of the sample liquid similar to the sample liquid prepared in the above-mentioned "Method for determining fine particle formation in water" was measured using a Wilhelmj surface tension meter.

Table 1 shows the raw materials, reaction conditions, and physical property values of the polymers obtained in the synthesis example.

In Table 1,
BuLi stands for normal butyllithium
St stands for styrene
αMeSt stands for α-methylstyrene and represents
tBMA represents methacrylic acid tert-butyl ester.

(Manufacturing example: Manufacturing method of aqueous pigment dispersion)
An aqueous pigment dispersion was obtained by the method of the following production example. The amount of raw materials used is described in the table below.

(Production Example 1 Method for producing aqueous pigment dispersion (K1))
150 g of carbon black (manufactured by Mitsubishi Chemical Corporation: CI Pigment Black 7) as a pigment, 45 g of a polymer (P-1) as a polymer (E), 135 g of triethylene glycol as a water-soluble solvent, 34 mass% water. A step 1 of charging 20 g of an aqueous potassium oxide solution into a 1.0 L intensive mixer (Nippon Eirich Co., Ltd.) and kneading at a rotor peripheral speed of 2.94 m / s and a pan peripheral speed of 1 m / s for 25 minutes was performed.

Subsequently, 450 g of ion-exchanged water was gradually added to the kneaded product in the intensive mixer container while continuing stirring, and then 140 g of ion-exchanged water was added and mixed, and the pigment concentration was 15.0% by mass. An aqueous pigment dispersion (K1) was obtained.

(Preparation method of binder resin (PB-1))
(Synthesis Example 2)
In a four-necked flask equipped with a stirrer, thermometer, cooling tube, and nitrogen introduction tube, 16 g of "Newcol 707SF" [anionic emulsifier manufactured by Nippon Emulsifier Co., Ltd.], "Neugen TDS-200D" [Daiichi Kogyo Seiyaku 6.5 g of nonionic emulsifier manufactured by Co., Ltd. and 220 g of deionized water were charged, the temperature was raised to 80 ° C. under a nitrogen stream, and then an aqueous solution prepared by dissolving 0.8 g of ammonium persulfate in 16 g of deionized water was added. Further, a mixed solution of 60 g of 2-ethylhexyl acrylate, 100 g of styrene, 27 g of methyl methacrylate, 3 g of acrylamide and 6 g of methacrylic acid was added dropwise over 3 hours. After completion of the dropping, the mixture was reacted for 2 hours, cooled to 25 ° C., neutralized with 1.5 g of 28 mass% ammonia water, and deionized water was added to adjust the non-volatile content to 45 mass% to adjust the glass transition temperature. An acrylic resin aqueous dispersion (PB-1) having (Tg) 35 ° C., an average particle size of 50 nm, and an acid value of 20 mgKOH / g was obtained. The final solid content concentration of the acrylic resin dispersion (PB-1) was 39% by mass.

(Preparation of water-based ink)
(Example 1 Method for preparing water-based ink)
As the aqueous pigment dispersion, 40.00 g of the aqueous pigment dispersion (K1), 17.14 g of AQUACER507 (polyolefin manufactured by BYK, average particle diameter 50 nm, melting point 130 ° C., non-volatile content 35% by mass), 0.6 g of triethylene glycol. , Distilled water 20.36 g, MB (3-methoxy-1-butanol manufactured by Daicel Co., Ltd.) 15.00 g, urea 5.0 g, triethanolamine 0.20 g, ACTICIDE MV4 (manufactured by So Japan Co., Ltd.) 0.10 g of preservative) and 1.60 g of SURFYNOL 104PG50 (acetylenedi alcohol-based surfactant manufactured by Air Products Co., Ltd.) were added and stirred to prepare a black water-based ink (J1).

(Examples 2 to 10 Water-based ink preparation method)
Water-based inks (J2) to (J10) were obtained in the same manner as in Example 1 except that the composition of the ink was changed to the composition shown in Tables 2 and 3.

(Comparative Examples 1 to 4 Method for preparing water-based ink)
Water-based inks (H1) to (H4) were obtained in the same manner as in Example 1 except that the composition of the ink was changed to the composition shown in Table 4.

In the table, the abbreviations are as follows.

TEG: Triethylene glycol 3MB: 3-Methoxy-1-butanol manufactured by Daicel Corporation TEA: Triethanolamine MV4: Preservative ACTICIDE MV4 manufactured by So Japan Co., Ltd.
SF104PG: SURFYNOL 104PG50 manufactured by Air Products & Chemicals
AQ507: Polyolefin wax manufactured by BYK, non-volatile content 35% by mass, melting point 130 ° C.
AQ515: Polyolefin wax manufactured by BYK, non-volatile content 35% by mass, melting point 135 ° C.
AQ530: Polyolefin wax manufactured by BYK, non-volatile content 30% by mass, melting point 130 ° C.
AQ539: Polyolefin wax manufactured by BYK, non-volatile content 35% by mass, melting point 90 ° C.
AQ593: Polyolefin wax manufactured by BYK, non-volatile content 30% by mass, melting point 160 ° C.
Water: Ion-exchanged water

(Evaluation of water-based ink)
The characteristics of the water-based inks (J1) to (J12) and (H1) to (H2) were evaluated as follows. The results are shown in Tables 5-7.

[Abrasion resistance evaluation]
By filling the Kyocera inkjet head KJ4B-YH with the water-based inks obtained in Examples and Comparative Examples, and setting the head difference of the ink sub-tank from the head nozzle plate surface to +35 cm and negative pressure -5.0 kPa. The supply pressure was adjusted. The gap between the inkjet head and the corona-treated surface of the OPP film (Pyrene P2161; biaxially stretched polypropylene film manufactured by Toyobo Co., Ltd.) and PET film (Espet E5102; biaxially stretched polyester film manufactured by Toyobo Co., Ltd.). Was set to 1.2 mm. The drive conditions of the head are the standard voltage and standard temperature of the inkjet head, the droplet size is set to 18 pL, 100% density solid printing is performed, and then the ink is dried in a warm air dryer at 60 ° C. for 5 minutes. Obtained printed matter.

Next, "Bencot AP-2" manufactured by Ozu Corporation was fixed to the head portion of the "rubbing tester" manufactured by Taihei Rikagaku Kogyo, and the printed surface of the printed matter was rubbed 10 times with a load of 500 g.

Next, the scraped surface of the printed matter was read by a scanner, and the ratio (color residual ratio) of the scratched area to have the same color as the non-scraped surface was analyzed by the image analysis software "ImageJ".
⊚: Color residual rate of printed matter is 70% or more ○: Color residual rate of printed matter is 50% or more and less than 70% ×: Color residual rate of printed matter is less than 50%

[Setability evaluation]
By filling the Kyocera inkjet head KJ4B-YH with the water-based inks obtained in Examples and Comparative Examples, and setting the head difference of the ink sub-tank from the head nozzle plate surface to +35 cm and negative pressure -5.0 kPa. The supply pressure was adjusted. The gap between the inkjet head and the corona-treated surface of the OPP film (Pyrene P2161; biaxially stretched polypropylene film manufactured by Toyobo Co., Ltd.) and PET film (Espet E5102; biaxially stretched polyester film manufactured by Toyobo Co., Ltd.) Was set to 1.2 mm. The drive conditions of the head are the standard voltage and standard temperature of the inkjet head, the droplet size is set to 18 pL, 100% density solid printing is performed, and then the ink is dried in a warm air dryer at 60 ° C. for 1 minute. Obtained printed matter.

The printed matter is taken out from a warm air dryer and left at room temperature for 1 minute, and then a corona-untreated surface of an OPP film different from the above is placed on the printed surface of the printed matter, and a weight is applied so as to have a load of 100 g / cm ^2. Was set and left for 1 minute.

After 1 minute, the weight stone is removed, the OPP film overlaid on the printed matter is peeled off, the printed surface of the printed matter is read with a scanner, and the printed area has the same color as before the OPP film is overlaid. The ratio (color residual ratio) was analyzed with the image analysis software "ImageJ".

◯: Color residual rate of printed matter is 70% or more ×: Color residual rate of printed matter is less than 70%

It was confirmed that the water-based inks of Examples 1 to 12 had good wear resistance and settability on the OPP and PET films. In particular, the water-based inks of Examples 1 to 4 and Examples 7 to 12 using polyolefins having a melting point of 120 ° C. or higher and lower than 160 ° C. have a coating film residual ratio of 70% or more, which is a particularly good result. I confirmed that it would be.

On the other hand, the water-based ink of Comparative Example 1 had a composition that did not contain ureas, so that the abrasion resistance of the OPP and PE substrates was insufficient. Since the water-based ink of Comparative Example 2 did not contain polyolefin, the abrasion resistance on the OPP and PET films was poor.

It is a schematic diagram of the microreactor used in this invention.

1: T-shaped micro mixer M1
2: T-shaped micro mixer M2
3: T-shaped micro mixer M3
4: Tube reactor R1
5: Tube reactor R2
6: Tube reactor R3
7: Tube reactor P1 for precooling
8: Tube reactor P2 for precooling
9: Tube reactor P3 for precooling
10: Tube reactor P4 for precooling

Claims (8)

An ink used for printing on a recording medium having a water absorption of 10 g / m ² or less when the contact time between the recording medium and pure water is 100 msec , and the inks are polyolefin (A) and ethylene urea. An ink containing (B), an aqueous medium (C) and a coloring material (D). The ink according to claim 1, wherein the polyolefin (A) has a melting point of 120 ° C. or higher and lower than 160 ° C. The ink according to claim 1 or 2 , wherein the mass ratio [(A) / (B)] of the polyolefin (A) to the compound (B) is in the range of 1/6 to 6/1. The ink according to any one of claims 1 to 3 , wherein the polyolefin (A) is contained in an amount of 0.5% by mass to 6% by mass based on the total amount of the ink. The ink according to any one of claims 1 to 4 , wherein the polyolefin (A) has an average particle size in the range of 30 nm to 150 nm. The ink according to any one of claims 1 to 5 , wherein the aqueous medium (C) contains water and a water-soluble organic solvent. An inkjet recording ink comprising the ink according to any one of claims 1 to 6 . The step [1] in which the ink for inkjet recording according to claim 7 is adjusted to a viscosity of 3 mPa · s to 20 mPa · s and a surface tension of 20 mN / m to 40 mN / m, and a range of the viscosity and surface tension. The step [2] in which the ink adjusted to the above is discharged to a recording medium having a water absorption amount of 10 g / m ² or less when the contact time between the recording medium and pure water is 100 msec , and 50 ° C to 100. A method for producing a printed matter, which comprises a step [3] of drying at ° C.

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