INKJET RECORDING METHOD AND INKJET RECORDING MEDIUM

Abstract

An inkjet recording method for printing an inkjet recording medium comprising an ink-receiving layer containing inorganic pigment, starch and copolymer latex on a surface of a base with inkjet ink as aqueous pigment ink, a content of the inorganic pigment being 10 g/m.sup.2 or more to 35 g/m.sup.2 or less in the ink-receiving layer,and a content of calcium carbonate being from 80% by weight or more to 100% by weight or less, the inkjet ink containing one or more selected from self dispersed pigment and pigment containing water-insoluble polymer particles, from 10% by weight or more to 48% by weight or less of a water-soluble organic solvent A having a boiling point of 230° C. or less, from 0% by weight or more to 5.0% by weight or less of a water-soluble organic solvent B having a boiling point of 280° C. or more, from 42% by weight or more to 70% by weight or less of water.

Claims

1. An inkjet recording method for printing an inkjet recording medium with inkjet ink as aqueous pigment ink, the inkjet recording medium comprising an ink-receiving layer containing inorganic pigment, starch and copolymer latex at least on one surface of a base, from 10 g/m.sup.2 or more to 35 g/m.sup.2 or less of the inorganic pigment being contained in the ink-receiving layer in terms of a solid content, a content of calcium carbonate in the inorganic pigment being from 80% by weight or more to 100% or less by weight, a content of silica in the inorganic pigment being from 0% by weight or more to 10% by weight or less, the starch being contained at 0.5 parts by weight or more, and the copolymer latex being contained at from 3.0 parts by weight or more to 9.0 parts by weight or less with respect to 100 parts by weight of the inorganic pigment, the inkjet ink containing one or more types of pigment selected from self dispersed pigment and pigment containing water-insoluble polymer particles, from 10% by weight or more to 48% by weight or less of a water-soluble organic solvent A having a boiling point of 230° C. or less, from 0% by weight or more to 5.0% by weight or less of a water-soluble organic solvent B having a boiling point of 280° C. or more, from 42% by weight or more to 70% by weight or less of water.

2. The inkjet recording method according to claim 1, wherein the printing is performed by one-pass printing at a frequency of 20 kHz or more with inkjet ink as aqueous pigment ink.

3. The inkjet recording method according to claim 1, wherein when the content of calcium carbonate per unit area of the ink-receiving layer is represented as: X (g/m.sup.2), and the amount of the water-soluble organic solvent A per dot area when the inkjet recording medium is dot printed with the inkjet ink is represented as Y (g/m.sup.2), the ratio Y/X satisfies 9×10.sup.−15<=Y/X<=47×10.sup.−15.

4. The inkjet recording method according to claim 1, wherein the inkjet ink further contains from 0.5% by weight or more to 3.0% by weight or less of a nonionic surfactant.

5. The inkjet recording method according to claim 1, wherein the pigment of the inkjet ink contains water-insoluble polymer particles.

6. The inkjet recording method according to claim 1, wherein the calcium carbonate has a Volume 50% average particle diameter (D.sub.50) of 0.3 to 10.0 μm as measured by a laser light scattering method.

7. The inkjet recording method according to claim 6, wherein the copolymer latex includes acrylonitrile styrene butadiene copolymer.

8. An inkjet recording medium used in the inkjet recording method according to claim 1, comprising an ink-receiving layer containing inorganic pigment, starch and copolymer latex at least on one surface of a base, from 10 g/m.sup.2 or more to 35 g/m.sup.2 or less of the inorganic pigment being contained in the ink-receiving layer in terms of a solid content, a content of calcium carbonate in the inorganic pigment being from 80% by weight or more to 100% by weight or less, a content of silica in the inorganic pigment being from 0% by weight or more to 10% by weight or less, the starch being contained at 0.5 parts by weight or more, and the copolymer latex being contained at from 3.0 parts by weight or more to 9.0 parts by weight or less with respect to 100 parts by weight of the inorganic pigment.

9. The inkjet recording medium according to claim 8, wherein the calcium carbonate has a Volume 50% average particle diameter (D.sub.50) of 0.3 to 10.0 μm as measured by a laser light scattering method.

10. The inkjet recording medium according to claim 9, wherein the Volume 50% average particle diameter (D.sub.50) is 0.5 to 1.9 μm.

11. The inkjet recording medium according to claim 8, wherein the copolymer latex is a copolymer at least polymerizing (A) an aliphatic conjugated dienemonomer and (B) other vinylmonomer copolymerizable with (A).

12. The inkjet recording medium according to claim 8, wherein an amount of the starch is from 1.0 parts by weight or more to 3.0 parts by weight or less with respect to 100 parts by weight of the inorganic pigment.

13. The inkjet recording medium according to claim 8, wherein the amount of the copolymer latex is from 5.0 parts by weight or more to 7.0 parts by weight or less with respect to 100 parts by weight of the inorganic pigment.

14. The inkjet recording medium according to claim 8, wherein white paper glossiness at a light incident angle of 75 degrees according to JIS-Z8741 of the surface of the ink-receiving layer is from 3% or more to less than 40%.

15. The inkjet recording medium according to claim 8, wherein the copolymer latex includes an acrylonitrile styrene butadiene copolymer.

Description

EXAMPLES

[0195] Hereinafter, the present invention will be further described in greater detail through examples. In the examples, respective physical properties were measured by the following methods. Note that “parts” and “%” denote “parts by weight” and “% by weight” unless otherwise noted.

(1) Measurement of Weight-Average Molecular Weight of Water-Insoluble Polymer

[0196] An eluent was prepared by dissolving phosphoric acid and lithium bromide into N,N-dimethylformamide so that each concentration was 60 mmol/L and 50 mmol/L. Using the eluent, a molecular weight of the water-insoluble polymer was measured by gel permeation chromatography [GPA apparatus (HLA-8120GPA), column (TSK-GEL, α-M×2) manufactured by Toso Corporation, flowrate: 1 mL/min]. As a reference material, monodisperse polystyrene having a known molecular weight was used.

2) Measurement of Solid Content Concentration of Aqueous Dispersion of Pigment Containing Polymer Particles

[0197] 10.0 g of sodium sulfate that was to be constant weight in a desiccator was weighed into a 30 mL ointment container, and about 1.0 g of the aqueous dispersion of the pigment containing polymer particles was added and mixed. The mixture was measured for weight accurately, and maintained at 105° C. for 2 hours. Volatile components were removed. The mixture was allowed to be stand for further 15 minutes in the desiccator, and the weight was measured. The weight of the pigment containing polymer particles after the volatile components were removed was regarded as the solid content, which was divided by the weight of the added sample (aqueous dispersion=pigment containing polymer particles+dispersion medium) to provide the solid content concentration.

(3) Measurement of Average Particle Size of Pigment Containing Polymer Particles

[0198] Measurement was made using a laser particle analysis system (model: ELS-8000, Cumulant analysis, manufactured by Otsuka Electronics, Co., Ltd.,). The dispersion used was diluted with water so that the concentration of the pigment containing polymer particles to be measured was about 5×10.sup.−3% by weight. The measurement conditions were: temperature at 25° C., angle between the incident light and the detector of 90°, cumulative number of 100. As a refractive index of the dispersion solvent, the refractive index of water (1.333) was entered.

(4) pH of Inkjet Ink

[0199] A desk top type pH meter “F-71” (manufactured by HORIBA Ltd.) using a pH electrode “6337-10D” (manufactured by HORIBA Ltd.) was used to measure the pH of the ink at 25° C.

<Preparation of Pigment Containing Polymer Particles>

Preparation Example I

Preparation of Water-Insoluble Polymer (a-1) Solution

[0200] To a reaction vessel equipped with two dropping funnels, the monomer, the solvent, the polymerization initiator (2,2′-azobis (2,4-dimethyl valeronitrile) (manufactured by Wako Pure Chemical Industries, Ltd., product name: V-65B), the polymerization chain transfer agent (2-mercaptethanol) (manufactured by Kishida Chemical Co., Ltd.) shown in Table 1 “initially charged monomer solution” were charged, mixed, and purged with nitrogen gas to provide an initially charged monomer solution.

[0201] Next, the monomer, the solvent, the polymerization initiator, and the polymerization chain transfer agent shown in Table 1 “dropping monomer solution 1” were mixed to provide a dropping monomer solution 1, which was charged to a dropping funnel 1, and purged with nitrogen gas. The monomer, solvent, the polymerization initiator, and the polymerization chain transfer agent shown in Table 1 “dropping monomer solution 2” were mixed to provide a dropping monomer solution 2, which was charged to a dropping funnel 2, and purged with nitrogen gas.

[0202] Styrenic macromer in each Table is a 50% by weight toluene solution having a number average molecular weight 6000 manufactured by Toagosei Co., Ltd. under the product name: AS-6S. Blemmer PP1000 is a product name of polypropylene glycol monomethacrylate (propylene oxide average addition molar number=5, terminal: hydrogen atom) manufactured by NOF Corporation. The polymerization initiator V-65B is a product name of 2,2′-azobis (2,4-dimethyl valeronitrile) manufactured by Wako Pure Chemical Industries, Ltd. NK ester TM-40G is a product name of methoxy polyethylene glycol monomethacrylate (ethylene oxide average addition molar number=4) manufactured by Shin Nakamura Chemical, Co., Ltd.

[0203] Methacrylic acid and styrene in each Table are reagents manufactured by Wako Pure Chemical Industries, Ltd., and lauryl methacrylate is a reagent manufactured by Tokyo Chemical Industry Co., Ltd.

[0204] The initially charged monomer solution in the reaction vessel was stirred under nitrogen atmosphere, and was maintained at 77° C. The dropping monomer solution 1 in the dropping funnel 1 was gradually dropped into the reaction vessel for 3 hours. Then, the dropping monomer solution 2 in the dropping funnel 2 was gradually dropped into the reaction vessel for 2 hours. After dropping, the mixture solution in the reaction vessel was stirred at 77° C. for 0.5 hours.

[0205] Then, the polymerization initiator solution was prepared by dissolving 1.1 parts of the above-described polymerization initiator (V-65B) into 47.3 parts of methylethylketone (manufactured by Wako Pure Chemical Industries, Ltd.,), was added to the mixture solution, and stirred at 77° C. for 0.5 hour to be matured. Further, the polymerization initiator solution was prepared, added and matured 12 times. Then, the reaction solution in the reaction vessel was maintained at 80° C. for 1 hour, and 8456 parts of methylethylketone was added so that the solid content concentration was 36.0%, thereby providing the water-insoluble polymer a-1 solution. The water-insoluble polymer a-1 had the weight-average molecular weight of 82,000.

[0206] A monomer charging ratio in each of Table 1 to Table 3 is a value at a solid content of 50% in the styrenic macromer, and is a value at a solid content of 100% in other monomers. A monomer solution charging amount in each of Table 1 to Table 3 is a value in the solution.

TABLE-US-00001 TABLE 1 Initially charged Dropping Dropping Monomer monomer monomer monomer charged solution solution solution percentage (parts) 1 (parts) 2 (parts) (weight %) Methacrylic acid 1152 288 16.0 Styrene 396 3168 396 44.0 Styrenic macromer 270 2430 15.0 Blemmer PP1000 225 1800 225 25.0 Methylethylketone 157.5 1732.5 1260 Polymerization 72 18 Average initiator V-65B molecular weight Mw Mercaptoethanol 1.3 8.82 2.52 82000

Preparation Example II

Preparation of Water-Insoluble Polymer a-2 Solution

[0207] The water-insoluble polymer (a-2) solution (polymer solid content concentration 36%) was provided as shown in Table 2 in accordance with the preparation method described in Preparation example I except that Blemmer PP1000 was replaced with NK ester TM-40G in “initially charged monomer solution” in Table 1. The weight-average molecular weight of the water-insoluble polymer (a-2) was 67,000.

TABLE-US-00002 TABLE 2 Initially charged Dropping Dropping Monomer monomer monomer monomer charged solution solution solution percentage (parts) 1 (parts) 2 (parts) (weight %) Methacrylic acid 1152 288 16.0 Styrene 396 3168 396 44.0 Styrenic macromer 270 2430 15.0 NK ester TM-40G 225 1800 225 25.0 Methylethylketone 157.5 1732.5 1260 Polymerization 72 18 Average initiator V-65B molecular weight Mw Mercaptoethanol 1.3 8.82 2.52 67000

Preparation Example III

Preparation of Water-Insoluble Polymer a-3 Solution

[0208] The water-insoluble polymer (a-3) solution (polymer solid content concentration 36%) was provided using the initially charged monomer solution, the dropping monomer solution 1, and the dropping monomer solution 2 in Table 3 in accordance with the preperation method described in Preparation example I. The weight-average molecular weight of the water-insoluble polymer (a-3) was 53,000.

TABLE-US-00003 TABLE 3 Initially charged Dropping Dropping Monomer monomer monomer monomer charged solution solution solution percentage (parts) 1 (parts) 2 (parts) (weight %) Methacrylic acid 1100 288 14.0 Styrene 671 5200 671 66.0 Lauryl methacrylate 200 1780 20.0 Methylethylketone 157.5 1732.5 1260 Polymerization 72 18 Average initiator V-65B molecular weight Mw Mercaptoethanol 1.3 8.82 2.52 53000

Preparation Example IV

Preparation of Aqueous Dispersion of Pigment Containing Polymer Particles A

[0209] 178.7 parts of the water-insoluble polymer (a-1) solution (solid content concentration 36.0%) provided in Preparation example I were mixed with 45 parts of methylethylketone (MEK) to provide the MEK solution of the water-insoluble polymer (a-1). Into a vessel with a volume of 2 L having a disper impeller, the MEK solution of the water-insoluble polymer (a-1) was charged, which was stirred at 1400 rpm. 511.4 parts of ion exchange water, 22.3 parts of a 5N sodium hydroxide solution (manufactured by Wako Pure Chemical Industries, Ltd.,), and 1.7 parts of a 25% ammonia water solution (manufactured by Wako Pure Chemical Industries, Ltd.,) were added thereto. The mixture was adjusted such that the degree of neutralization by sodium hydroxide was 78.8 mol %, and the degree of neutralization by ammonia was 21.2 mol %, and was stirred at 1400 rpm for 15 minutes while cooling in a water bath at 0° C.

[0210] Then, 214 parts of carbon black (manufactured by Cabot Japan Corp., product name: MONARCH 880) was added, which was stirred at 6400 rpm for 1 hour. The resultant pigment mixture was 9-pass dispersed processed at a pressure of 150 MPa using Microfluidizer “M-7115” (manufactured by Microfluidics Co.) to provide a dispersed product (solid content concentration was 25.0%).

[0211] 324.5 parts of the dispersed product provided in the above-described Step were charged into a 2 L eggplant flask, to which 216.3 parts of ion exchange water was added (solid content concentration 15.0%). Using a “rotary evaporator” (N-1000S, manufactured by Tokyo Rikakikai Co., Ltd.), the mixture was held at a rotation number of 50 r/min in a warm bath adjusted to 32° C. at a pressure of 0.09 MPa for 3 hours to remove the organic solvent. Furthermore, the warm bath was adjusted to 62° C., the pressure was decreased to 0.07 MPa, and the mixture was concentrated to have the solid content concentration of 25%.

[0212] The resultant concentrated product was charged into 500 ml angle rotor, and was centrifuged using a high-speed cooling centrifuge (himaa AR22G, manufactured by Hitachi Koki Co., Ltd., setting temperature 20° C.) at 7000 rpm for 20 minutes. Thereafter, a liquid layer portion was filtered using a 1.2 μm filter (MAP-010XS manufactured by Roki Techno Co., Ltd.).

[0213] To 300 parts of the resultant filtrate (57.7 parts of the pigment, 17.3 parts of the water-insoluble polymer a-1), 0.68 parts of Proxel LV (S) (manufactured by Lonza Japan, fungicide, active component 20%) was added, and 40.23 parts of ion exchange water was further added so that the solid content concentration was 22.0%, which was stirred at room temperature for 1 hour to provide the aqueous dispersion of the pigment containing polymer particles A (aqueorus pigment dispersion; average particle size 105 nm, pH 9.0).

[0214] The aqueous dispersion of the pigment containing polymer particles A is referred to as “aqueous dispersion A”.

Preparation Example V

Preparation of Aqueous Dispersion of Pigment Containing Polymer Particles B

[0215] To 100 parts of the aqueous dispersion A, 0.27 parts of an epoxy cross-linking agent (trimethylol propane polyglycidyl ether, manufactured by Nagase ChemteX Corporation, product name: Denacol EX321L, epoxy equivalent 129) was added (corresponding to 25 mol % to carboxylic acid being a cross-linking reaction point contained in methacrylic acid of the polymer), and 0.95 parts of ion exchange water was added thereto so that the solid content concentration was 22.0%. The mixture was stirred at 70° C. for 5 hours, was cooled to room temperature, thereby providing the aqueous dispersion of the pigment containing polymer particles B (aqueorus pigment dispersion; average particle size 106 nm, pH 9.9).

[0216] The aqueous dispersion of the pigment containing polymer particles B is referred to as “aqueous dispersion B”.

Preparation Example VI

Preparation of Aqueous Dispersion of Pigment Containing Polymer Particles C

[0217] The aqueous dispersion of the pigment containing polymer particles C (aqueorus pigment dispersion; average particle size 95 nm, pH 9.0) was provided in accordance with the preparation method in Preparation example IV except that the water-insoluble polymer (a-1) was replaced with the water-insoluble polymer (a-2) described in Preparation example II.

[0218] The aqueous dispersion of the pigment containing polymer particles C is referred to as “aqueous dispersion C”.

Preparation Example VII

Preparation of Aqueous Dispersion of Pigment Containing Polymer Particles D

[0219] The aqueous dispersion of the pigment containing polymer particles D (aqueorus pigment dispersion; average particle size 115 nm, pH 9.0) was provided in accordance with the preparation method in Preparation example IV except that the water-insoluble polymer (a-1) was replaced with the insoluble polymer (a-3) described in Preparation example II.

[0220] The aqueous dispersion of the pigment containing polymer particles D is referred to as “aqueous dispersion D”.

Preparation Example VIII

Preparation of Aqueous Dispersion of Pigment Containing Polymer Particles F

[0221] The aqueous dispersion of the pigment containing polymer particles F (aqueorus pigment dispersion; average particle size 120 nm, pH 8.5) was provided in accordance with the preparation method in Preparation example IV except that carbon black was replaced with azo pigment (Pigment Yellow 74, manufactured by Sanyo Color Works, LTD., Product name: Fast Yellow 7414).

[0222] The aqueous dispersion of the pigment containing polymer particles F is referred to as “aqueous dispersion F”.

Preparation Example IX

Preparation of Aqueous Dispersion of Pigment Containing Polymer Particles G

[0223] The aqueous dispersion of the pigment containing polymer particles G (aqueorus pigment dispersion; average particle size 125 nm, pH 8.9) was provided in accordance with the preparation method in Preparation example IV except that carbon black was replaced with quinacridone pigment (Pigment Red 122, manufactured by DIC Corporation, Product name: FASTGEN SUPER MAGENTA RGT).

[0224] The aqueous dispersion of the pigment containing polymer particles G is referred to as “aqueous dispersion G”.

Preparation Example X

Preparation of Aqueous Dispersion of Pigment Containing Polymer Particles H

[0225] The aqueous dispersion of the pigment containing polymer particles H (aqueorus pigment dispersion; average particle size 100 nm, pH 9.0) was provided in accordance with the preparation method in Preparation example IV except that carbon black was replaced with copper phthalocyanine pigment (Pigment Blue 15:3, manufactured by DIC Corporation, Product name: FASTGEN BLUE TGR-SD).

[0226] The aqueous dispersion of the pigment containing polymer particles H is referred to as “aqueous dispersion H”.

<Preparation of Pigment Dispersed with Water Soluble Polymer>

Preparation Example XI

Preparation of Aqueous Dispersion of Pigment I Dispersed with Water Soluble Polymer

[0227] The aqueous dispersion of the pigment I dispersed with water soluble polymer (aqueorus pigment dispersion; average particle size 95 nm, pH 9.1) was provided in accordance with the preparation method in Preparation example IV except that styrene-acrylic acid copolymer (product name: Joncyl 68 (manufactured by BASF Japan Co., Ltd.) was used as water soluble polymer in place of the water-insoluble polymer (a-1).

[0228] The aqueous dispersion of the pigment I is referred to as “aqueous dispersion I”.

<Preparation of Inkjet Ink>

Preparation Example 1

Preparation of Ink 1

[0229] To 41.3 parts of the aqueous dispersion A described in Preparation example IV (corresponds to a pigment concentration 7% in the ink, solid content concentration 22%), 35 parts of propylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.), 0.3 parts of Surfynol 104PG50 (manufactured by Nissin Chemical Co., Ltd., solid content concentration 50%, propylene glycol 50%), 0.6 parts of Emulgen 120 (manufactured by Kao Corporation), 5.0 parts of glycerin (manufactured by Kao Corporation), and water (which gave 100 parts of the ink) were added, which was stirred at room temperature for 30 minutes, and then was filtrated with 1.2 μm filter (MAP-010XS) to provide ink 1.

Preparation Example 2

Preparation of Ink 2

[0230] Ink 2 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 10 parts of propylene glycol 10, 15 parts of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.,), 5.0 parts of glycerin.

Preparation Example 3

Preparation of Ink 3

[0231] Ink 3 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 35 parts of propylene glycol and 10 parts of diethylene glycol.

Preparation Example 4

Preparation of Ink 4

[0232] Ink 4 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 35 parts of propylene glycol.

Preparation Example 5

Preparation of Ink 5

[0233] Ink 5 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 25 parts of propylene glycol and 5.0 parts of glycerin, and the surfactant was replaced with 1.0 parts of Surfynol 104PG50 and 1.0 parts of Emulgen 120.

Preparation Example 6

Preparation of Ink 6

[0234] Ink 6 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 25 parts of propylene glycol, and the surfactant was replaced with 1.5 parts of Surfynol 104PG50 and 1.5 parts of Emulgen 120.

Preparation Example 7

Preparation of Ink 7

[0235] Ink 7 was provided in accordance with the preparation method in Preparation example 5 except that the water-soluble organic solvent was replaced with 20 parts of propylene glycol and 5.0 parts of glycerin, and 4.5 parts of the water-insoluble polymer particles Neocryl A1127 (corresponds to the water-insoluble polymer particles 2% in the ink, manufactured by DSM NeoResins, Inc., solid content concentration 44% by weight, average particle size 65 nm, pH 7.7) was added.

Preparation Example 8

Preparation of Ink 8

[0236] Ink 8 was provided in accordance with the preparation method in Preparation example 7 except that the aqueous dispersion A was replaced with 41.9 parts of the aqueous dispersion B in Preparation example V (corresponding to pigment concentration 7% in the ink).

Preparation Example 9

Preparation of Ink 9

[0237] Ink 9 was provided in accordance with the preparation method in Preparation example 7 except that the aqueous dispersion A was replaced with the aqueous dispersion C in Preparation example VI.

Preparation Example 10

Preparation of Ink 10

[0238] Ink 10 was provided in accordance with the preparation method in Preparation example 7 except that the aqueous dispersion A was replaced with the aqueous dispersion D in Preparation example VII.

Preparation Example 11

Preparation of Ink 11

[0239] Ink 11 was provided in accordance with the preparation method in Preparation example 7 except that 41.3 parts of the aqueous dispersion A was replaced with 46.7 parts of the aqueous dispersion D (self dispersion type pigment manufactured by SENSIENT INDUSTRIAL COLORS LLC, (product name SENSIJET BLACK SDP100), solid content concentration 15%).

Preparation Example 12

Preparation of Ink 12

[0240] Ink 12 was provided in accordance with the preparation method in Preparation example 4 except that the water-soluble organic solvent was replaced with 35 parts of 1,2 butanediol (manufactured by Tokyo Chemical Industry Co., Ltd.

Preparation Example 13

Preparation of Ink 13

[0241] Ink 13 was provided in accordance with the preparation method in Preparation example 4 except that the water-soluble organic solvent was replaced with 35 parts of 3-methyl 1,3 butanediol (manufactured by Tokyo Chemical Industry Co., Ltd.).

Preparation Example 14

Preparation of Ink 14

[0242] Ink 14 was provided in accordance with the preparation method in Preparation example 4 except that the water-soluble organic solvent was replaced with 35 parts of 1,2 pentane diol (manufactured by Tokyo Chemical Industry Co., Ltd.).

Preparation Example 15

Preparation of Ink 15

[0243] Ink 15 was provided in accordance with the preparation method in Preparation example 4 except that the water-soluble organic solvent was replaced with 35 parts of 1,2 hexanediol (manufactured by Tokyo Chemical Industry Co., Ltd.).

Preparation Example 16

Preparation of Ink 16

[0244] Ink 16 was provided in accordance with the preparation method in Preparation example 4 except that the water-soluble organic solvent was replaced with 35 parts of diethylene glycol monobutyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.

Preparation Example 17

Preparation of Ink 17

[0245] Ink 17 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 40 parts of propylene glycol.

Preparation Example 18

Preparation of Ink 18

[0246] Ink 18 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 45 parts of propylene glycol.

Preparation Example 19

Preparation of Ink 19

[0247] Ink 19 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 47 parts of propylene glycol.

Preparation Example 20

Preparation of Ink 20

[0248] Ink 20 was provided in accordance with the preparation method in Preparation example 7 except that the aqueous dispersion A was replaced with the aqueous dispersion F in Preparation example VIII.

Preparation Example 21

Preparation of Ink 21

[0249] Ink 21 was provided in accordance with the preparation method in Preparation example 7 except that the aqueous dispersion A was replaced with the aqueous dispersion G in Preparation example IX.

Preparation Example 22

Preparation of Ink 22

[0250] Ink 22 was provided in accordance with the preparation method in Preparation example 7 except that the aqueous dispersion A was replaced with the aqueous dispersion H in Preparation example X.

Preparation Example 23

Preparation of Ink 23

[0251] Ink 23 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 40 parts of diethylene glycol.

Preparation Example 24

Preparation of Ink 24

[0252] Ink 24 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 20 parts of propylene glycol and 10 parts of glycerin.

Preparation Example 25

Preparation of Ink 25

[0253] Ink 25 was provided in accordance with the preparation method in Preparation example 5 except that the water-soluble organic solvent was replaced with 10 parts of propylene glycol and 5 parts of diethylene glycol.

Preparation Example 26

Preparation of Ink 26

[0254] Ink 26 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 30 parts of glycerin.

Preparation Example 27

Preparation of Ink 27

[0255] Ink 27 was provided in accordance with the preparation method in Preparation example 4 except that the aqueous dispersion A was replaced with the aqueous dispersion I in Preparation example XI, and the water-soluble organic solvent was replaced with 30 parts of propylene glycol.

Preparation Example 28

Preparation of Ink 28

[0256] Ink 28 was provided in accordance with the preparation method in Preparation example 1 except that the water-soluble organic solvent was replaced with 50 parts of propylene glycol.

[0257] Table 4 shows compositions (solid contents) of the inkjet ink. Note that propylene glycol includes that derived from Surfynol 104PG50 being the surfactant.

TABLE-US-00004 TABLE 4 Inkjet ink (composition; wt %) Self dispersed pigment Water-soluble organic solvent Prepa- or pigment Water-soluble organic solvent A (b.p. 230° C. or less) ration aqueous containing Surfactant 3-methyl Diethylene Exam- disper- polymer Surfynol Emulgen Propylene 1,2butane- 1,3butane- 1,2pentane 1,2hexan glycol mono- ple sion particles 104PG50 120 glycol diol diol diol diol buthyl ether Boiling point of water-soluble organic solvent (° C.) 188 194 203 210 224 230 1 A 9.1 0.15 0.60 35.15 2 A 9.1 0.15 0.60 10.15 3 A 9.1 0.15 0.60 35.15 4 A 9.1 0.15 0.60 35.15 5 A 9.1 0.50 1.00 25.50 6 A 9.1 0.75 1.50 25.75 7 A 9.1 0.50 1.00 20.50 8 B 9.2 0.50 1.00 20.50 9 C 9.1 0.50 1.00 20.50 10 D 9.1 0.50 1.00 20.50 11 E 7.0 0.50 1.00 20.50 12 A 9.1 0.15 0.60 0.15 35.0 13 A 9.1 0.15 0.60 0.15 35.0 14 A 9.1 0.15 0.60 0.15 35.0 15 A 9.1 0.15 0.60 0.15 35.0 16 A 9.1 0.15 0.60 0.15 35.0 17 A 9.1 0.15 0.60 40.15 18 A 9.1 0.15 0.60 45.15 19 A 9.1 0.15 0.60 47.50 20 F 9.1 0.15 0.60 35.15 21 G 9.1 0.15 0.60 35.15 22 H 9.1 0.15 0.60 35.15 23 A 9.1 0.15 0.60 0.15 24 A 9.1 0.15 0.60 20.15 25 A 9.1 0.50 1.00 10.50 26 A 9.1 0.15 0.60 0.15 27 I 9.1 0.15 0.60 30.15 28 A 9.1 0.15 0.60 50.15 Self dispersed Water-soluble organic solvent pigment Water-soluble Prepa- or pigment organic solvent B Water-insoluble Water ration aqueous containing Surfactant Others (b.p. 280° C. polymer particles Ion Exam- disper- polymer Surfynol Emulgen Diethylene or more) Neocryl exchange ple sion particles 104PG50 120 glycol Glycerin A1127 water Boiling point of water-soluble organic solvent (° C.) 244 290 — — 1 A 9.1 0.15 0.60 5.0 50.0 2 A 9.1 0.15 0.60 15.0 5.0 60.0 3 A 9.1 0.15 0.60 10.0 45.0 4 A 9.1 0.15 0.60 55.0 5 A 9.1 0.50 1.00 5.0 58.9 6 A 9.1 0.75 1.50 62.9 7 A 9.1 0.50 1.00 5.0 2.0 61.9 8 B 9.2 0.50 1.00 5.0 2.0 61.8 9 C 9.1 0.50 1.00 5.0 2.0 61.9 10 D 9.1 0.50 1.00 5.0 2.0 61.9 11 E 7.0 0.50 1.00 5.0 2.0 64.0 12 A 9.1 0.15 0.60 55.0 13 A 9.1 0.15 0.60 55.0 14 A 9.1 0.15 0.60 55.0 15 A 9.1 0.15 0.60 55.0 16 A 9.1 0.15 0.60 55.0 17 A 9.1 0.15 0.60 50.0 18 A 9.1 0.15 0.60 45.0 19 A 9.1 0.15 0.60 42.6 20 F 9.1 0.15 0.60 55.0 21 G 9.1 0.15 0.60 55.0 22 H 9.1 0.15 0.60 55.0 23 A 9.1 0.15 0.60 40.0 50.0 24 A 9.1 0.15 0.60 10.0 60.0 25 A 9.1 0.50 1.00 5.0 73.9 26 A 9.1 0.15 0.60 30.0 60.0 27 I 9.1 0.15 0.60 60.0 28 A 9.1 0.15 0.60 40.0

<Production of Inkjet Recording Medium>

[0258] In the following production of inkjet recording media A to W, “parts” and “%” denote “parts by weight” and “% by weight” in terms of a solid content unless otherwise noted. The coating weight is a solid content per one surface.

<Base>

[0259] 0.5 parts of a paper reinforcing agent (cationized starch), 0.55 parts of aluminum sulfate and 13 parts of calcium carbonate were added to 100 parts of the pulp material consisting of 87 parts of bleached hardwood kraft pulp (LBKP) having a CSF of 390 ml and 13 parts of bleached softwood kraft pulp (NBKP) having the CSF of 480 ml to provide a paper stock. The base having a basis weight of 80 g/m2 was made from the paper stock using a fourdrinier paper making machine.

<Coating Color for Ink-Receiving Layer>

[0260] A blend below was stirred and dispersed together with 32.0 parts of water in a ratio (parts by weight) shown in Table 5 to provide the coating color for the ink-receiving layer.

[0261] Calcium carbonate (manufactured by Fimatec Ltd., product name: FMT-90, D.sub.50: 1.2 μm)

[0262] Starch (manufactured by Penford Corporation, product name: PG295)

[0263] Acrylonitrile butadiene-based copolymer latex (manufactured by JSR Corporation, product name: NP-150).

[0264] In some preparation examples, as other pigment, clay (manufactured by Huber Inc., product name: Hydra gloss) or silica (manufactured by Tosoh•silica Corporation, product name: NIPGEL AY-200) was further added.

[0265] In each of Preparation examples N, O, P, Q, each inkjet recording medium was produced similar to Preparation example A except that 100 parts of calcium carbonate (manufactured by Omya A G, product name: Hydro curve 90, D.sub.50: 0.3 μm), calcium carbonate (manufactured by Fimatec Ltd., product name: FMT-97, D.sub.50: 1.0 μm), calcium carbonate (manufactured by Fimatec Ltd., product name: FMT-65, D.sub.50: 2.0 μm), or calcium carbonate (manufactured by Sankyo Seifun Co., product name: Escalon A, D.sub.50: 10.0 μm) was used in place of the calcium carbonate (manufactured by Fimatec Ltd., product name: FMT-90, D.sub.50: 1.2 μm).

[0266] Table 5 shows each D.sub.50 value of calcium carbonate. D.sub.50 was measured by the above-described laser particle size measuring apparatus (Mastersizer S type manufactured by Malvern Instruments Ltd., light source: red right, 633 nm (He—Ne laser), blue right, 466 nm (LED). Upon the measurement, the dispersion where calcium carbonate is dispersed in water was used.

[0267] Then, the coating color for the ink-receiving layer was coated on one surface of the base using a blade coater such that a total of the inorganic pigment in terms of a solid content per one surface was the value shown in Table 5. Thereafter, drying was done. Then, calendaring was performed twice by a soft nip calendar (linear pressure: 20 kN/m, roll temperature: 40° C.) to produce each inkjet recording medium in each Preparation example shown in Table 5.

TABLE-US-00005 TABLE 5 Inkjet recording medium Copolymer Calcium carbonate Other pigment Starch latex Coating Prepa- Blending Blending Blending Blending weight of Total of ration amount amount amount amount ink absorb- Calcium Other inorganic Copolymer exam- (parts by D.sub.50 (parts by (parts by (parts by ing layer carbonate pigment pigment Starch latex ple weight) (μm) Type weight) weight) weight) (g/m.sup.2) (g/m.sup.2) (g/m.sup.2) (g/m.sup.2) (g/m.sup.2) (g/m.sup.2) A 100 1.2 None 0.0 1.0 6.0 15.0 14.0 0.0 14.0 0.0093 0.0561 B 100 1.2 None 0.0 1.0 6.0 10.0 9.3 0.0 9.3 0.0093 0.0561 C 100 1.2 None 0.0 1.0 6.0 25.0 23.4 0.0 23.4 0.0093 0.0561 D 100 1.2 None 0.0 1.0 6.0 35.0 32.7 0.0 32.7 0.0093 0.0561 E 95 1.2 Clay 5.0 1.0 6.0 15.0 13.3 0.0 13.4 0.0093 0.0561 F 90 1.2 Clay 10.0 1.0 6.0 15.0 12.6 0.1 12.7 0.0093 0.0561 G 90 1.2 Silica 10.0 1.0 6.0 15.0 12.6 0.1 12.7 0.0093 0.0561 H 100 1.2 None 0.0 0.5 6.0 15.0 14.1 0.0 14.1 0.0047 0.0563 I 100 1.2 None 0.0 3.0 6.0 15.0 13.8 0.0 13.8 0.0275 0.0550 J 100 1.2 None 0.0 5.0 6.0 15.0 13.5 0.0 13.5 0.0450 0.0541 K 100 1.2 None 0.0 1.0 3.0 15.0 14.4 0.0 14.4 0.0096 0.0288 L 100 1.2 None 0.0 1.0 7.0 15.0 13.9 0.0 13.9 0.0093 0.0648 M 100 1.2 None 0.0 1.0 9.0 15.0 13.6 0.0 13.6 0.0091 0.0818 N 100 0.3 None 0.0 1.0 6.0 15.0 14.0 0.0 14.0 0.0093 0.0561 O 100 1.0 None 0.0 1.0 6.0 15.0 14.0 0.0 14.0 0.0093 0.0561 P 100 2.0 None 0.0 1.0 6.0 15.0 14.0 0.0 14.0 0.0093 0.0561 Q 100 10.0 None 0.0 1.0 6.0 15.0 14.0 0.0 14.0 0.0093 0.0561 R 75 1.2 Clay 25.0 1.0 6.0 15.0 10.5 0.2 10.7 0.0093 0.0561 S 75 1.2 Silica 25.0 1.0 6.0 15.0 10.5 0.2 10.7 0.0093 0.0561 T 100 1.2 None 0.0 0.2 6.0 15.0 14.1 0.0 14.1 0.0019 0.0565 V 100 1.2 None 0.0 1.0 1.5 15.0 14.6 0.0 14.6 0.0098 0.0146 W 100 1.2 None 0.0 1.0 11.0 15.0 13.4 0.0 13.4 0.0089 0.0982

<Evaluation of Printed Matter by Inkjet Recording>

[0268] The inkjet recording was performed using the inkjet ink and each inkjet recording medium shown in Table 4 and Table 5. The printed matter was produced by the following method and evaluated.

<Production of Printed Matter>

[0269] The inkjet ink shown in Table 4 was charged to a printing evaluation apparatus for one-pass printing (manufactured by Tritek Co., Ltd.) equipped with the inkjet head “KJ4B-QA06NTB-STDV” or “KJ4B-YH06WST-STDV” (manufactured by Kyocera Corporation) at a temperature of 23±1° C. and a relative humidity of 50±5%.

[0270] The setting was as follows: a head voltage of 26V, a head temperature of 32° C., a resolution of 600 dpi, number of flushing times before discharging of 200, and a negative pressure of −4.0 kPa. A frequency (20, 30 kHz for KJ4B-QA06NTB-STDV, and 40 kHz for KJ4B-YH06WST-STDV), and a liquid drop size upon ink discharging were as described in Table 6 and Table 7.

[0271] The inkjet recording medium was fixed to a conveyer of the printing evaluation apparatus under a reduced pressure so that a longitudinal direction of the inkjet recording medium and a conveying direction were the same.

[0272] A printing command was transferred to the printing evaluation apparatus. A solid image with 100% injection amount (600×600 dpi), and an image with 10% injection amount (for measuring a dot diameter) were printed on the ink-receiving layer of the inkjet recording medium using the inkjet ink to produce a printed matter.

<Evaluation1: Measurement of Ratio Y/X of Content X (g/m.sup.2) of Calcium Carbonate Per Unit Area of Inkjet Recording Medium and Amount Y (g/m.sup.2) of Water-Soluble Organic Solvent A Per Dot Area>

[0273] Firstly, Y (g/m.sup.2) was determined as follows: an image was provided using a handy type image evaluation system PIAS (registered trademark)-II (manufactured by QEA Corporation, using high resolution optical module) so that 10 points or more of ink dots were included for 1 field of view on the printed matter (image with 10% injection amount). An average particle size of each dot within the image was calculated. The measurement was performed for 5 fields of view, and the average particle sizes in the respective fields of view were averaged to employ as the average dot diameter.

[0274] An average particle size of each dot was determined by recognizing an ink part (=dots) by binarizing the image (differentiating the recording medium from the ink part) from a circle diameter corresponding to the area of the ink part (dots).

average particle size (μm)=√(4A/π); A=dot area (μm.sup.2)

[0275] In addition, an area of a perfect circle having the average dot diameter was calculated, and was regarded as the dot area. Next, the content (g) of the water-soluble organic solvent A in one dot was calculated by a percentage (%) of the water-soluble organic solvent A in the ink×the liquid drop size (pl: picoliter=×10.sup.−15 m.sup.3)×ink specific gravity of 1.05 (g/cm.sup.3) from the content of the water-soluble organic solvent A in the inkjet ink and the liquid drop size being a specific gravity of the inkjet ink regarded as 1.05. Then, Y (g/m.sup.2) was determined.

[0276] From Table 5, the content X (g/m.sup.2) of calcium carbonate was determined per unit area of the ink-receiving layer (printed surface) of the inkjet recording medium to calculate Y/X.

<Evaluation 2. Evaluation of Drying Properties>

[0277] A 450 g weight was prepared around which a plain paper (product name: Xerox 4200) was wound. After 5 seconds and 10 seconds of printing the printed matter (solid image), the weight was placed on the solid image for 5 seconds. The printing density of the surface of the plain paper wound around the weight on which the color was attached (contact surface with the solid image) was measured. The printing density was measured for 10 points on the contact surface of the paper using an optical densitometer “SpeatroEye” (manufactured by GretagMacbeth LLC) in a measurement mode (ANSI, Pap, Pol), and the average value was determined. The smaller the value is, the better the drying properties are.

[0278] The evaluation was made by the following standards. When the evaluation is Good or Not Bad, there is no practical problem.

(Evaluation Standards)

[0279]

TABLE-US-00006 Good: printing density 0.1 or less (printed surface is substantially dried) Not Bad: printing density 0.11 to 0.15 (a part of printed surface is insufficiently dried) Bad: printing density exceeding 0.15 (printed surface is insufficiently dried)

<Evaluation 3. Evaluation of Fixing Properties>

[0280] A 450 g weight was prepared around which a plain paper (product name: Xerox 4200) was wound. After 1 minute and 5 minutes of printing the printed matter (solid image), the weight was placed on the solid image for reciprocatively sliding 10 times. The printing density of the surface of the plain paper wound around the weight on which the color was attached (contact surface with the solid image) was measured. The measurement was made similar to Evaluation 2 for 5 points on the contact surface of the paper, and the average value was determined. The smaller the value is, the better the fixing properties are.

[0281] The evaluation was made by the following standards. When the evaluation is Good or Not Bad, there is no practical problem.

(Evaluation Standards)

[0282]

TABLE-US-00007 Good: printing density 0.1 or less (almost no peeling off on printed surface) Not Bad: printing density 0.11 to 0.4 (a little peeling off on printed surface) Bad: printing density exceeding 0.4 (greatly peeling off on printed surface)

<Evaluation 4. Evaluation of Printing Density>

[0283] After the printed matter (solid image) was allowed to stand at a temperature of 23±1° C. and a relative humidity of 50±5% for one day, the printing density of the solid image for any 10 points was measured using the optical densitometer “SpeatroEye” (manufactured by GretagMacbeth LLC), and the average value was determined. The greater the value is, the better colo properties are.

[0284] When a numerical value is 1.60 or more, it is good.

<Evaluation 5. Evaluation of Glossiness>

[0285] After the printed matter (solid image) and the surface of the ink-receiving layer non-printed (white paper) were allowed to stand at a temperature of 23±1° C. and a relative humidity of 50±5% for one day, 60° glossiness according to JIS-Z8741 was measured five times using a glossmeter (manufactured by Nippon Denshoku Industries, Co., Ltd., product name: HANDY GLOSSMETER, part number: PG-1), and the average value was determined. The greater the value is, the higher glossiness is.

[0286] In the matte coating paper for offset printing, it is good when the 60° glossiness (white paper glossiness) at the non-printed part is 3% or more and when the 60° glossiness at the printed part is 10% or more.

<Evaluation 6. Evaluation of Offset Printing Texture>

[0287] After the printed matter (solid image) was allowed to stand at a temperature of 23±1° C. and a relative humidity of 50±5% for one day, surface feelings on both of the surface of the ink-receiving layer as the printed surface on which the solid image was printed and the surface of the ink-receiving layer as the non-printed surface of the white paper were evaluated visually by the following standards:

[0288] When the evaluation is Good or Not Bad, there is no practical problem.

(Evaluation Standards)

[0289] Good: offset printing type texture is provided.

[0290] Not Bad: offset printing type-like texture is provided.

[0291] Bad: no offset printing type texture is provided.

<Evaluation 7. Evaluation of Discharging Properties>

[0292] Each combination of the inkjet ink and the inkjet recording medium in each Example was printed by the printing evaluation apparatus, and was allowed to stand for 30 minutes without protecting a nozzle surface. Thereafter, a pattern for distinguishing the discharge from all nozzles (2656 nozzles) was printed on both side high quality plain paper <recycled paper> (manufactured by Seiko Epson Corporation, model KA4250NPDR). Unusable nozzle numbers (clogged nozzle that do not discharge normally) was counted, and the discharge properties were evaluated by the following standards: The smaller the unusable nozzle numbers are, the better the discharging properties are.

[0293] When the evaluation is Good or Not Bad, there is no practical problem.

(Evaluation Standards)

[0294] Good: No unusable nozzles

[0295] Not Bad: Unusable nozzles are 1 to 5

[0296] Bad: Unusable nozzles are 6 or more

[0297] Table 6 to Table 8 show the results.

TABLE-US-00008 TABLE 6 Inkjet Content of recording Ink discharging water-soluble Inkjet medium conditions organic solvent Average dot Y Drying properties ink Preparation Frequency Liquid drop A in one dot diameter (×10.sup.−15 Y/X After 5 sec No. example (kHz) size(pl) (×10.sup.−21 g) (×10.sup.−6 m) g/m.sup.2) (×10.sup.−15) of printing Example 1 1 A 30 12 4.43 54.5 475 33.9 Good Example 2 1 A 30 7 2.58 50.0 329 23.5 Good Example 3 1 A 30 5 1.85 43.0 318 22.7 Good Example 4 1 A 20 12 4.43 55.5 458 32.7 Good Example 5 2 A 30 12 1.28 54.0 140 10.0 Good Example 6 3 A 30 12 4.43 53.0 502 35.8 Good Example 7 3 A 30 7 2.58 50.0 329 23.5 Good Example 8 3 A 30 5 1.85 42.0 333 23.8 Good Example 9 3 A 20 12 4.43 54.5 475 33.9 Good Example 10 3 A 40 12 4.43 55.0 466 33.3 Good Example 11 4 A 30 12 4.43 55.0 466 33.3 Good Example 12 5 A 30 12 3.21 69.0 215 15.3 Good Example 13 6 A 30 12 3.24 83.0 150 10.7 Good Example 14 5 A 30 7 1.87 62.0 155 11.1 Good Example 15 5 A 30 5 1.34 56.0 136 9.7 Good Example 16 5 A 20 12 3.21 70.0 209 14.9 Good Example 17 5 A 40 12 3.21 70.5 206 14.7 Good Example 18 7 A 30 12 2.58 68.0 178 12.7 Good Example 19 8 A 30 12 2.58 69.0 173 12.3 Good Example 20 9 A 30 12 2.58 69.0 173 12.3 Good Example 21 10 A 30 12 2.58 67.0 183 13.1 Not Bad Example 22 11 A 30 12 2.58 65.0 195 13.9 Good Example 23 12 A 30 12 4.43 53.5 493 35.2 Good Example 24 13 A 30 12 4.43 54.0 484 34.5 Good Example 25 14 A 30 12 4.43 54.0 484 34.5 Good Drying properties Fixing properties 60° glossiness Offset After 10 sec After 1 min After 5 min Printing Printed White printing Discharging of printing of printing of printing density matter paper texture properties Example 1 Good Not Bad Not Bad 1.83 16 5 Good Good Example 2 Good Not Bad Not Bad 1.76 15 5 Good Good Example 3 Good Not Bad Not Bad 1.63 15 5 Good Good Example 4 Good Not Bad Not Bad 1.84 16 5 Good Good Example 5 Good Not Bad Not Bad 1.85 17 5 Good Good Example 6 Good Not Bad Not Bad 1.86 17 5 Good Good Example 7 Good Not Bad Good 1.80 17 5 Good Good Example 8 Good Not Bad Good 1.67 17 5 Good Good Example 9 Good Not Bad Not Bad 1.85 18 5 Good Good Example 10 Good Not Bad Not Bad 1.87 18 5 Good Good Example 11 Good Not Bad Not Bad 1.86 18 5 Good Good Example 12 Good Not Bad Good 2.16 15 5 Good Good Example 13 Good Not Bad Good 2.21 18 5 Good Not Bad Example 14 Good Not Bad Good 1.86 14 5 Good Good Example 15 Good Not Bad Good 1.75 15 5 Good Good Example 16 Good Not Bad Good 2.18 14 5 Good Good Example 17 Good Not Bad Good 2.17 14 5 Good Good Example 18 Good Good Good 1.82 14 5 Good Good Example 19 Good Good Good 1.84 15 5 Good Good Example 20 Good Good Good 1.86 15 5 Good Good Example 21 Good Not Bad Good 1.73 12 5 Good Good Example 22 Good Not Bad Not Bad 1.69 10 5 Good Good Example 23 Good Not Bad Not Bad 1.81 17 5 Good Good Example 24 Good Not Bad Not Bad 1.81 16 5 Good Good Example 25 Good Not Bad Not Bad 1.83 17 5 Good Good

TABLE-US-00009 TABLE 7 Inkjet Content of recording Ink discharging water-soluble Inkjet medium conditions organic solvent Average dot Y Drying properties ink Preparation Frequency Liquid drop A in one dot diameter (×10.sup.−15 Y/X After 5 sec No. example (kHz) size(pl) (×10.sup.−21 g) (×10.sup.−6 m) g/m.sup.2) (×10.sup.−15) of printing Example 26 15 A 30 12 4.43 55.0 466 33.3 Not Bad Example 27 16 A 30 12 4.43 56.0 450 32.1 Not Bad Example 28 1 B 30 12 4.43 62.0 367 39.3 Not Bad Example 29 1 C 30 12 4.43 54.5 475 20.3 Good Example 30 1 D 30 12 4.43 54.0 484 14.8 Good Example 31 1 E 30 12 4.43 56.0 450 33.8 Not Bad Example 32 1 F 30 12 4.43 57.0 434 34.4 Not Bad Example 33 1 G 30 12 4.43 54.0 484 38.3 Good Example 34 1 H 30 12 4.43 50.0 564 40.1 Not Bad Example 35 1 I 30 12 4.43 63.0 355 25.8 Good Example 36 1 J 30 12 4.43 85.0 195 14.4 Not Bad Example 37 1 K 30 12 4.43 50.0 564 39.1 Good Example 38 1 L 30 12 4.43 54.5 475 34.2 Good Example 39 1 M 30 12 4.43 68.0 305 22.4 Not Bad Example 40 1 N 30 12 4.43 54.0 484 34.5 Not Bad Example 41 1 O 30 12 4.43 54.5 475 33.9 Good Example 42 1 P 30 12 4.43 55.0 466 33.3 Good Example 43 1 Q 30 12 4.43 55.0 466 33.3 Good Example 44 17 A 30 12 5.06 55.0 533 38.0 Good Example 45 18 A 30 12 5.69 54.0 621 44.3 Good Example 46 19 A 30 12 5.99 54.0 654 46.6 Good Example 47 20 A 30 12 4.43 56.0 450 32.1 Good Example 48 21 A 30 12 4.43 55.0 466 33.3 Good Example 49 22 A 30 12 4.43 56.0 450 32.1 Good Drying properties Fixing properties 60° glossiness Offset After 10 sec After 1 min After 5 min Printing Printed White printing Discharging of printing of printing of printing density matter paper texture properties Example 26 Good Not Bad Not Bad 1.83 18 5 Good Good Example 27 Not Bad Not Bad Not Bad 1.83 17 5 Good Good Example 28 Good Not Bad Not Bad 1.83 16 5 Good Good Example 29 Good Not Bad Not Bad 1.82 16 5 Good Good Example 30 Good Not Bad Good 1.80 15 5 Good Good Example 31 Good Not Bad Not Bad 1.85 18 7 Good Good Example 32 Not Bad Not Bad Not Bad 1.85 20 8 Good Good Example 33 Good Not Bad Not Bad 1.83 13 4 Not Bad Good Example 34 Good Not Bad Not Bad 1.83 15 5 Good Good Example 35 Good Not Bad Not Bad 1.82 16 6 Good Good Example 36 Not Bad Not Bad Not Bad 1.82 18 7 Good Good Example 37 Good Not Bad Not Bad 1.78 15 5 Good Good Example 38 Good Not Bad Not Bad 1.83 16 5 Good Good Example 39 Good Not Bad Not Bad 1.82 17 6 Good Good Example 40 Not Bad Not Bad Not Bad 1.84 16 15 Good Good Example 41 Good Not Bad Not Bad 1.82 16 5 Good Good Example 42 Good Not Bad Not Bad 1.83 16 4 Good Good Example 43 Good Not Bad Not Bad 1.83 15 3 Not Bad Good Example 44 Good Not Bad Not Bad 1.86 18 5 Good Good Example 45 Good Not Bad Not Bad 1.86 18 5 Good Good Example 46 Good Not Bad Not Bad 1.83 18 5 Good Good Example 47 Good Not Bad Good 1.95 26 5 Good Good Example 48 Good Not Bad Not Bad 1.81 21 5 Good Good Example 49 Good Not Bad Not Bad 2.14 23 5 Good Good

TABLE-US-00010 TABLE 8 Inkjet Content of recording Ink discharging water-soluble Inkjet medium conditions organic solvent Average dot Y Drying properties ink Preparation Frequency Liquid drop A in one dot diameter (×10.sup.−15 Y/X After 5 sec No. example (kHz) size(pl) (×10.sup.−21 g) (×10.sup.−6 m) g/m.sup.2) (×10.sup.−15) of printing Comp-Ex 1 23 A 30 12 0.02 57.5 2 0.1 Bad Comp-Ex 2 24 A 30 12 2.54 57.0 249 17.8 Bad Comp-Ex 3 25 A 30 12 1.32 53.0 150 10.7 Good Comp-Ex 4 26 A 30 12 0.02 58.0 2 0.1 Bad Comp-Ex 5 26 A 30 7 0.01 52.0 1 0.1 Bad Comp-Ex 6 26 A 30 5 0.01 45.0 1 0.1 Bad Comp-Ex 7 26 A 20 12 0.02 59.0 2 0.1 Bad Comp-Ex 8 26 A 40 12 0.02 59.5 2 0.1 Bad Comp-Ex 9 27 A 30 12 3.80 53.0 431 30.7 Bad Comp-Ex 10 28 A 30 12 6.32 52.0 744 53.1 Good Comp-Ex 11 1 R 30 12 4.43 58.0 419 39.9 Bad Comp-Ex 12 1 S 30 12 4.43 50.0 564 53.7 Good Comp-Ex 13 1 T 30 12 4.43 48.0 612 43.3 Not Bad Comp-Ex 14 1 V 30 12 4.43 45.0 697 47.6 Bad Comp-Ex 15 1 W 30 12 4.43 103.0 133 9.9 Bad Drying properties Fixing properties 60° glossiness Offset After 10 sec After 1 min After 5 min Printing Printed White printing Discharging of printing of printing of printing density matter paper texture properties Comp-Ex 1 Bad Not Bad Not Bad 1.83 18 5 Good Good Comp-Ex 2 Bad Not Bad Not Bad 1.83 18 5 Good Good Comp-Ex 3 Good Bad Bad 1.69 10 5 Good Bad Comp-Ex 4 Bad Not Bad Not Bad 1.83 18 5 Good Good Comp-Ex 5 Bad Bad Not Bad 1.65 17 5 Good Good Comp-Ex 6 Bad Bad Bad 1.45 15 5 Good Good Comp-Ex 7 Bad Bad Not Bad 1.82 18 5 Good Good Comp-Ex 8 Bad Bad Not Bad 1.81 18 5 Good Good Comp-Ex 9 Bad Bad Bad 1.71 18 5 Good Bad Comp-Ex 10 Good Bad Not Bad 1.80 18 5 Good Good Comp-Ex 11 Bad Bad Bad 1.83 18 9 Good Good Comp-Ex 12 Good Bad Not Bad 1.59 12 3 Bad Good Comp-Ex 13 Not Bad Bad Bad 1.80 14 5 Good Good Comp-Ex 14 Good Bad Not Bad 1.69 14 5 Not Bad Good Comp-Ex 15 Bad Not Bad Not Bad 1.85 16 7 Good Good

[0298] As apparent from Table 6 to Table 8, in each Example where the ink-receiving layer of the inkjet recording medium contains predetermined amounts of inorganic pigment, starch, copolymer latex and calcium carbonate, and the inkjet ink contains predetermined pigment, predetermined amount of the water-soluble organic solvent A, B and water, the ink discharging properties, the ink-drying properties, the fixing properties, the printing density, and the glossiness have excellent, and the offset printing type texture was provided.

[0299] On the other hand, in Comparative Examples 1, 4 to 8 where the inkjet ink 23, 26, in which content of the water-soluble organic solvent A was less than 10% by weight, was used, the ink-drying properties were decreased. In Comparative Example 10 where inkjet ink 28, in which the content of the water-soluble organic solvent A exceeds 48% by weight, was used, the ink fixing properties were decreased.

[0300] In Comparative Example 2 where the inkjet ink 24, in which content of the water-soluble organic solvent B exceeds 5% by weight, was used, the ink-drying properties were decreased.

[0301] In Comparative Example 3 where the inkjet ink 25, in which content of water exceeds 70% by weight, was used, the ink fixing properties were decreased. Also, as the ink-drying properties were too high, ink was solidified on the surface of the head nozzle, and the discharging properties were decreased.

[0302] In Comparative Example 9 where the pigment dispersed with water soluble polymer was used, ink stability was originally low, many aggregates were produced when the ink was dried on the surface of the head nozzle, and the drying properties and the fixing properties were decreased.

[0303] In Comparative Examples 11,12 where the content of calcium carbonate in the inorganic pigment of the ink-receiving layer was less than 80% by weight, at least any of the ink-drying properties and the fixing properties was deteriorated. Specifically, in Comparative Example 11 where the inorganic pigment contains clay, the offset printing type texture was good similar to each Example. However, as clay less absorbs ink than calcium carbonate, the ink-drying properties were especially poor. In Comparative Example 12, as the inorganic pigment contains silica, the ink-drying properties were good. However, the printing density was decreased, and the offset printing type texture was also poor.

[0304] In Comparative Example 13 where the amount of starch was less than 0.5 parts by weight with respect to 100 parts by weight of the inorganic pigment, as the water retention properties of the coating color for the ink-receiving layer was insufficient, the coating unevenness of the ink-receiving layer was great, and the ink fixing properties were poor in the part where the ink-receiving layer was less coated.

[0305] In Comparative Example 14 where the amount of the copolymer latex is less than 3 parts by weight of the copolymer latex with respect to 100 parts by weight of the inorganic pigment, ink was not sufficiently spread upon the inkjet recording, and the ink fixing properties were poor in the part where the ink was excess.

[0306] In Comparative Example 15 where the amount of the copolymer latex exceeds 9 parts by weight, the ink was excessively spread, and spaces in the ink-receiving layer were insufficient, resulting in poor ink-drying properties.