Ink set and method for producing printed matter

Abstract

An ink set containing an inkjet ink and a treatment liquid used in combination with the inkjet ink, wherein the inkjet ink contains a pigment, a water-soluble organic solvent, a surfactant and water, the water-soluble organic solvent contains a glycol ether-based organic solvent having a specific structure, the treatment liquid contains a coagulant, the coagulant contains calcium nitrate in an amount of 6.8 to 20.8% by mass relative to the total mass of the treatment liquid, and the amount of compounds contained in the treatment liquid that have three or more hydroxyl groups is not more than 15% by mass relative to the total mass of the treatment liquid.

Claims

1. An ink set comprising an inkjet ink, and a treatment liquid used in combination with the inkjet ink, wherein the inkjet ink comprises a pigment, a water-soluble organic solvent, a surfactant and water, the water-soluble organic solvent comprises a glycol ether-based organic solvent (A) represented by general formula (1) shown below, the treatment liquid comprises a coagulant, a pH adjuster, and a binder resin having a number average molecular weight in a range from 3,000 to 90,000, the coagulant comprises calcium nitrate in an amount of 6.8 to 20.8% by mass relative to a total mass of the treatment liquid, and in the treatment liquid, an amount of compounds having three or more hydroxyl groups is not more than 15% by mass relative to a total mass of the treatment liquid:
R1-(-O—CH.sub.2CH.sub.2—)n-OH  General formula (1): wherein R1 represents an alkyl group of 2 to 4 carbon atoms which may have a branched structure, and n represents 2 or 3.

2. The ink set according to claim 1, wherein a pH of the treatment liquid is within a range from 3.5 to 11.

3. The ink set according to claim 1, wherein the treatment liquid also comprises a nonionic surfactant, and the nonionic surfactant includes at least one compound selected from the group consisting of an acetylene-based surfactant and a siloxane-based surfactant.

4. The ink set according to claim 1, wherein the inkjet ink also comprises a pigment dispersing resin.

5. The ink set according to claim 1, wherein the glycol ether-based organic solvent (A) represented by general formula (1) comprises a glycol ether-based organic solvent in which n represents 2.

6. The ink set according to claim 1, wherein the water-soluble organic solvent also comprises a diol-based solvent (B) having a surface tension at 25° C. of 30 to 50 mN/m.

7. The ink set according to claim 6, wherein a mass ratio of a blend amount of the glycol ether-based organic solvent (A) represented by general formula (1) to a blend amount of the diol-based solvent (B) having a surface tension at 25° C. of 30 to 50 mN/m is within a range from 1:0.5 to 1:7.5.

8. The ink set according to claim 1, wherein the binder resin is a water-soluble resin.

9. A method for producing inkjet ink printed matter that uses the ink set according to claim 1, the method comprising: a step of applying the treatment liquid to a recording medium formed from a paper substrate or a synthetic paper substrate, and a step of applying the inkjet ink by one-pass printing to a portion to which the treatment liquid has been applied.

10. The method for producing inkjet ink printed matter, according to claim 9, wherein in the step of applying the treatment liquid, the treatment liquid is applied to the recording medium so that an amount of calcium ions on a surface of the recording medium is within a range from 0.5 to 5.0 mmol/m.sup.2.

11. A printed matter obtained by printing the ink set according to claim 1 to a recording medium.

Description

EXAMPLES

(1) The present invention is described below in further detail using a series of examples and comparative examples. In the following description, unless particularly stated otherwise, “parts” and “%” mean “parts by mass” and “% by mass” respectively.

I. Preparation of Treatment Liquids

(2) (1) Preparation Example for PVA103 Varnish

(3) The materials described below were mixed at room temperature for one hour under constant stirring, and the temperature was then raised to 90° C. and mixing was continued for a further one hour. Subsequently, the thus obtained mixture was cooled to room temperature to obtain a PVA103 varnish.

(4) (Materials)

(5) PVA103 (a polyvinyl alcohol manufactured by Kuraray Co., Ltd. (degree of saponification: 98 to 99% (fully saponified), degree of polymerization: 300)) 25 parts

(6) Ion-exchanged water 75 parts

(7) (2) Preparation Example for Treatment Liquid 1

(8) A mixing container equipped with a stirrer was prepared, and the materials listed below were added sequentially to the container. The materials were mixed at room temperature for one hour under gentle stirring, and the temperature was then raised to 60° C. and mixing was continued for a further one hour. Subsequently, the thus obtained mixture was cooled to room temperature and filtered through a membrane filter having a pore size of 1 μm to obtain a treatment liquid 1.

(9) (Materials)

(10) TABLE-US-00001 Calcium nitrate tetrahydrate (manufactured by Yoneyama 9.8 parts Chemical Industry Co., Ltd.) Triethanolamine (TEA) 1 part 35% hydrochloric acid (35% HCl) 0.62 parts PVA103 varnish 20 parts 2-propanol (iPrOH) 4 parts Dynol 607 (an acetylene-based surfactant manufactured 0.4 parts by Air Products and Chemicals, Inc.) PROXEL GXL (a preservative, a 1,2-benzisothiazol-3-one 0.05 parts solution, manufactured by Arch Chemicals, Inc.) Ion-exchanged water 64.13 parts

(11) The viscosity of the obtained treatment liquid 1 at 25° C. was measured using an ε-type viscometer (TVE25L viscometer, manufactured by Toki Sangyo Co., Ltd.). Further, the pH of the treatment liquid 1 at 25° C. was measured using a desktop pH meter (F-72 manufactured by Horiba, Ltd.) and a standard ToupH electrode. These results are shown in Table 1.

(12) (3) Preparation Examples for Treatment Liquids 2 to 41

(13) With the exception of using the materials shown in Table 1, the same method as that described for the treatment liquid 1 was used to obtain treatment liquids 2 to 41. Further, the viscosity and pH of each treatment liquid was measured in the same manner as treatment liquid 1. The measurement results are shown in Table 1.

(14) TABLE-US-00002 TABLE 1 Treatment liquid No. 1 2 3 4 5 6 7 8 9 10 11 Blend Metal salt Ca(NO.sub.3).sub.2•4H.sub.2O 9.8 10.8 20 25 28.5 29.8 20 20 20 20 20 amount Compounds having Glycerol 8 10 15 (%) 3 or more Trimethylol- 10 hydroxyl groups propane SANNIX 10 GP-250 Glucose pH Base TEA 1 1 1 1 1 1 1 1 1 1 1 adjuster Acid 35% HCl 0.62 0.62 0.62 0.62 0.62 0.62 0.62 0.62 0.62 0.62 0.62 CH.sub.3COOH Other CH.sub.3COONa Binder resin PVA103 20 20 20 20 20 20 20 20 20 20 20 varnish (solid fraction: 25%) BYK190 (solid fraction: 40%) Organic Monohydric iPrOH (boiling 4 4 4 4 4 4 solvent alcohol point: 82° C.) Surfactant Acetylene Dynol 607 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Preservative PROXEL GXL 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water 64.13 63.13 53.93 48.93 45.43 44.13 49.93 47.93 42.93 47.93 47.93 Total 100 100 100 100 100 100 100 100 100 100 100 Treatment liquid viscosity (mPa .Math. s) 8.0 8.2 8.5 8.7 8.8 9.0 18.0 24.0 40.0 26.0 25.0 Treatment liquid pH 6.6 6.5 6.2 6.0 5.8 5.5 6.2 6.2 6.1 6.1 6.1 Calcium nitrate content (%) 6.8 7.5 13.9 17.4 19.8 20.7 13.9 13.9 13.9 13.9 13.9 Amount of organic solvent having 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 boiling point of 240° C. or higher (%) Treatment liquid No. 12 13 14 15 16 17 18 19 20 Blend Metal salt Ca(NO.sub.3).sub.2•4H.sub.2O 20 20 20 20 20 20 20 20 20 amount Compounds having Glycerol (%) 3 or more Trimethylol- hydroxyl groups propane SANNIX GP-250 Glucose 10 pH Base TEA 1 0.8 2 1 1 1 1 adjuster Acid 35% HCl 0.62 0.4 0.62 0.62 0.62 0.62 CH.sub.3COOH 1 Other CH.sub.3COONa 0.25 Binder resin PVA103 20 20 20 20 20 20 20 20 20 varnish (solid fraction: 25%) BYK190 (solid fraction: 40%) Organic Monohydric iPrOH (boiling 4 4 4 4 1 20 25 30 solvent alcohol point: 82° C.) Surfactant Acetylene Dynol 607 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 PROXEL GXL 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water 47.93 55.15 54.3 54.75 53.55 56.93 37.93 32.93 27.93 Total 100 100 100 100 100 100 100 100 100 Treatment liquid viscosity (mPa .Math. s) 32.0 8.0 8.2 8.3 9.0 8.5 8.5 8.5 8.5 Treatment liquid pH 6.1 2.2 3.6 7.8 10.8 6.1 6.1 6.1 6.1 Calcium nitrate content (%) 13.9 13.9 13.9 13.9 13.9 13.9 13.9 13.9 13.9 Amount of organic solvent having 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 boiling point of 240° C. or higher (%) Treatment liquid No. 21 22 23 24 25 26 27 28 29 30 31 Blend Metal salt Ca(NO.sub.3).sub.2•4H.sub.2O 20 20 20 20 20 20 20 20 20 20 20 amount CaCl.sub.2•2H.sub.2O (%) NaCl Compounds having Glycerol 3 or more hydroxyl groups pH Base TEA 1 1 1 1 1 1 1 1 1 1 adjuster Acid 35% HCl 0.62 0.6 0.5 0.4 0.62 0.62 0.62 0.62 0.62 0.62 Binder resin PVA103 20 20 20 20 20 20 20 20 20 20 20 varnish (solid fraction: 25%) BYK190 (solid fraction: 40%) Organic Monohydric iPrOH (boiling 4 4 4 4 4 solvent alcohol point: 82° C.) MB (boiling 20 point: 158° C.) Glycol 1,2-PD (boiling 20 10 35 point: 188° C.) 1,2-HexD 15 10 (boiling point: 224° C.) DEG (boiling 8 10 15 point: 244° C.) Surfactant Acetylene Dynol 607 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Surfynol 440 0.4 Surfynol 104E 0.4 Siloxane BYK348 0.4 Preservative PROXEL GXL 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water 37.93 37.95 43.05 50.15 47.93 42.93 33.93 20.55 53.93 53.93 53.93 Total 100 100 100 100 100 100 100 100 100 100 100 Treatment liquid viscosity (mPa .Math. s) 8.6 14.0 18.0 15.0 18.0 21.2 17.0 17.0 8.5 8.5 8.5 Treatment liquid pH 6.1 6.6 7.4 7.9 6.2 5.9 6.2 5.0 6.2 6.2 6.2 Calcium nitrate content (%) 13.9 13.9 13.9 13.9 13.9 13.9 13.9 13.9 13.9 13.9 13.9 Amount of organic solvent having 0.0 0.0 0.0 8.0 10.0 15.0 0.0 0.0 0.0 0.0 0.0 boiling point of 240° C. or higher (%) Treatment liquid No. 32 33 34 35 36 37 38 39 40 41 Blend Metal salt Ca(NO.sub.3).sub.2•4H.sub.2O 20 20 20 20 7.8 31.8 20 20 amount CaCl.sub.2•2H.sub.2O 15 (%) NaCl 20 Compounds having Glycerol 17.5 25 3 or more hydroxyl groups pH Base TEA 1 1 1 1 1 1 1 1 1 1 adjuster Acid 35% HCl 0.62 0.62 0.62 0.62 0.62 0.62 0.62 0.62 0.62 0.62 Binder resin PVA103 64 76 20 20 20 20 20 10 varnish (solid fraction: 25%) BYK190 (solid 10 12.5 fraction: 40%) Organic Monohydric iPrOH (boiling 4 4 4 4 solvent alcohol point: 82° C.) MB (boiling point: 158° C.) Glycol 1,2-PD (boiling point: 188° C.) 1,2-HexD (boiling point: 224° C.) DEG (boiling point: 244° C.) Surfactant Acetylene Dynol 607 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Surfynol 440 Surfynol 104E Siloxane BYK348 Preservative PROXEL GXL 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water 67.93 65.43 13.93 1.93 58.93 53.93 66.13 42.13 40.43 42.93 Total 100 100 100 100 100 100 100 100 100 100 Treatment liquid viscosity (mPa .Math. s) 4.5 5.0 100.0 120.0 8.0 8.5 8.0 9.0 43.0 50.0 Treatment liquid pH 6.0 6.0 5.5 5.6 6.5 6.2 6.6 5.5 6.1 6.1 Calcium nitrate content (%) 13.9 13.9 13.9 13.9 0.0 0.0 5.4 22.1 13.9 13.9 Amount of organic solvent having 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 boiling point of 240° C. or higher (%)

(15) Details regarding the abbreviations and product names for the materials shown in Table 1 are as follows.

(16) <1> Metal Salts

(17) Ca(NO.sub.3).sub.2.4H.sub.2O: calcium nitrate tetrahydrate

(18) CaCl.sub.2.2H.sub.2O: calcium chloride dihydrate

(19) NaCl: sodium chloride

(20) <2> Compounds Having Three or More Hydroxyl Groups

(21) SANNIX GP-250: a propylene oxide adduct of glycerol, manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight: 250

(22) <3> pH Adjusters

(23) TEA: triethanolamine

(24) 35% HCl: 35% hydrochloric acid

(25) <4> Binder Resins

(26) PVA103 varnish: as described above

(27) BYK190: an aqueous solution of a styrene-maleic acid resin (solid fraction: 40%) manufactured by BYK-Chemie Japan K.K.

(28) <5> Organic solvents

(29) iPrOH: 2-propanol (boiling point: 82° C., surface tension: 20.9 mN/m)

(30) MB: 3-methoxy-1-butanol (boiling point: 158° C., surface tension: 29.3 mN/m)

(31) 1,2-PD: 1,2-propanediol (boiling point: 188° C., surface tension: 35.1 mN/m)

(32) 1,2-HexD: 1,2-hexanediol (boiling point: 224° C., surface tension: 25.9 mN/m)

(33) DEG: diethylene glycol (boiling point: 244° C., surface tension: 44.2 mN/m)

(34) <6> Surfactants

(35) Dynol 607: an acetylene-based surfactant manufactured by Air Products and Chemicals, Inc. (Griffin method HLB value=8)

(36) Surfynol 440: an acetylene-based surfactant manufactured by Air Products and Chemicals, Inc. (Griffin method HLB value=8)

(37) Surfynol 104E: an acetylene-based surfactant manufactured by Air Products and Chemicals, Inc. (Griffin method HLB value=3)

(38) BYK348: a siloxane-based surfactant manufactured by BYK-Chemie Japan K.K. (Griffin method HLB value=10)

(39) <7> Additive (Preservative)

(40) PROXEL GXL: a 1,2-benzisothiazol-3-one solution, manufactured by Arch Chemicals, Inc.

II. Preparation of Inkjet Inks

(41) (1) Pigment Dispersing Resin

(42) <Production Example for Aqueous Solution of Pigment Dispersing Resin 1>

(43) A reaction container fitted with a gas inlet tube, a thermometer, a condenser and a stirrer was charged with 93.4 parts of butanol, and the container was flushed with nitrogen gas. Subsequently, the contents of the reaction container were heated to 110° C., and a mixture containing 20 parts of styrene, 40 parts of acrylic acid and 40 parts of behenyl acrylate as polymerizable monomers and 6 parts of a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise to the container over a period of two hours to achieve a polymerization reaction. Following completion of the dropwise addition, reaction was continued at 110° C. for a further three hours, an additional 0.6 parts of V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the reaction was continued at 110° C. for a further one hour, yielding a solution of a pigment dispersing resin (water-soluble pigment dispersing resin) 1.

(44) Following cooling of the solution of the pigment dispersing resin 1 to room temperature, 37.1 parts of dimethylaminoethanol was added to neutralize the solution, and 100 parts of water was then added to generate an aqueous solution of the dispersing resin 1. Subsequently, the aqueous solution was heated to at least 100° C., and the butanol was removed by azeotropic distillation with the water to adjust the solid fraction to 30%. In this manner, an aqueous solution of the pigment dispersing resin 1 with a solid fraction of 30% was obtained. The above term “aqueous solution” describes a solution containing an aqueous medium, and components dispersed and/or dissolved in the aqueous medium.

(45) Measurement of the pH of the aqueous solution (solid fraction: 30%) of the above pigment dispersing resin 1 using a desktop pH meter F-72 manufactured by Horiba, Ltd. revealed a pH of 9.7. Further, the acid value of the pigment dispersing resin 1 measured using an HLC-8120GPC device manufactured by Tosoh Corporation in accordance with method described above was 250 mgKOH/g, and the weight average molecular weight was 22,500.

(46) <Production Examples for Aqueous Solutions of Pigment Dispersing Resins 2 to 7>

(47) With the exceptions of altering the types and blend amounts of the polymerizable monomers and the amount of the polymerization initiator as shown below in Table 2, aqueous solutions (solid fraction: 30%) of pigment dispersing resins (water-soluble pigment dispersing resins) 2 to 7 were obtained in the same manner as the pigment dispersing resin 1.

(48) TABLE-US-00003 TABLE 2 Pigment dispersing resin 1 2 3 4 5 6 7 Polymerizable Styrene 20 20 30 35 45 20 20 monomers Acrylic acid 40 30 16 6 1 50 30 Lauryl methacrylate 50 44 59 54 30 50 Behenyl acrylate 40 Polymerization V-601 6 6 6 6 6 6 12 initiator Aqueous solution pH 9.7 8.1 8.5 8.8 9.2 7.4 8.1 Acid value (mgKOH/g) 250 200 110 40 15 350 200 Weight average molecular weight 22,500 15,000 13,000 11,000 15,000 28,000 8,000

(49) Table 2 shows the pH of the aqueous solution (solid fraction: 30%) of each pigment dispersing resin, the acid value of each pigment dispersing resin, and the weight average molecular weight of each pigment dispersing resin.

(50) <Production Example for Pigment Dispersing Resin 8>

(51) A reaction container fitted with a gas inlet tube, a thermometer, a condenser and a stirrer was charged with 45 parts of methyl ethyl ketone; 6.0 parts of acrylic acid, 30.0 parts of methyl methacrylate and 14.0 parts of lauryl methacrylate as polymerizable monomers; 0.15 parts of 2,2′-azobisisobutyronitrile as a polymerization initiator; and 0.65 parts of 2-(dodecylthiocarbonothioylthio)-isobutyric acid. Following flushing of the inside of the reaction container with nitrogen gas, the temperature was raised to 75° C., and a polymerization reaction was conducted for three hours, thus obtaining a copolymer (hydrophilic block) formed from acrylic acid, methyl methacrylate and lauryl methacrylate.

(52) The mixed solution in the reaction container prior to the flushing with nitrogen gas and the mixed solution obtained following the polymerization reaction were analyzed using a gas chromatography-mass spectrometer and compared with the detection peaks attributable to the acrylic acid, methyl methacrylate and lauryl methacrylate used as raw materials. The results revealed that in the mixed solution obtained following the polymerization reaction, almost no peaks attributable to acrylic acid, methyl methacrylate or lauryl methacrylate were observed. Based on these results, it is thought that almost all of the added polymerizable monomers polymerized. Further, the weight average molecular weight of the hydrophilic block measured using an HLC-8120GPC device manufactured by Tosoh Corporation was about 23,000.

(53) Following completion of the above polymerization reaction, the reaction system was cooled to normal temperature, and 45 parts of methyl ethyl ketone; and 10 parts of methyl methacrylate and 40 parts of benzyl methacrylate as polymerizable monomers were added to the reaction container. Following flushing of the inside of the reaction container with nitrogen gas, the temperature was raised to 75° C., and a polymerization reaction was conducted for three hours, thus obtaining a pigment dispersing resin (a water-insoluble resin) 8 composed of a block polymer having a copolymer (hydrophobic block) formed from methyl methacrylate and benzyl methacrylate added to the above hydrophilic block.

(54) In the same manner as described above for the hydrophilic block, a comparison with the detection peaks attributable to the polymerizable monomers was performed using a gas chromatography-mass spectrometer. The results revealed that almost all of the added methyl methacrylate and benzyl methacrylate had polymerized, confirming formation of the hydrophobic block. Further, the weight average molecular weight of the pigment dispersing resin 8 measured using an HLC-8120GPC device manufactured by Tosoh Corporation was about 54,000. Furthermore, the acid value of the pigment dispersing resin 8 measured using an HLC-8120GPC device manufactured by Tosoh Corporation in accordance with method described above was 45 mgKOH/g.

(55) Subsequently, the reaction system was cooled to normal temperature, the mixed solution was then removed from the reaction container, and methyl ethyl ketone was used to adjust the solid fraction to 40.3%, thus obtaining a methyl ethyl ketone solution of the pigment dispersing resin 8.

(56) <Production Example for Pigment Dispersing Resin 9>

(57) With the exception of using 12.0 parts of methacrylic acid and 12.0 parts of methyl methacrylate as polymerizable monomers; 0.2 parts of 2,2′-azobisisobutyronitrile as a polymerization initiator; and 0.85 parts of 2-(dodecylthiocarbonothioylthio)-isobutyric acid, a copolymer (hydrophilic block B) formed from methacrylic acid and methyl methacrylate was obtained in the same manner as the hydrophilic block of the pigment dispersing resin 8.

(58) In the same manner as that described for the hydrophilic block of the pigment dispersing resin 8, the mixed solution in the reaction container prior to the flushing with nitrogen gas and the mixed solution obtained following the polymerization reaction were analyzed and compared using a gas chromatography-mass spectrometer. The results revealed that almost all of the added polymerizable monomers had polymerized. Further, the weight average molecular weight of the hydrophilic block B measured using an HLC-8120GPC device manufactured by Tosoh Corporation was about 12,000.

(59) Furthermore, with the exceptions of using the reaction system containing the hydrophilic block B, and using 56 parts of methyl methacrylate, 10 parts of 2-ethylhexyl methacrylate and 10 parts of styrene as polymerizable monomers, a polymerization reaction was conducted in the same manner as that described for the pigment dispersing resin 8. As a result, a pigment dispersing resin (a water-insoluble resin) 9 composed of a block polymer having a copolymer (hydrophobic block B) formed from methyl methacrylate, 2-ethylhexyl methacrylate and styrene added to the above hydrophilic block B was obtained.

(60) In the same manner as described above for the hydrophilic block, a comparison with the detection peaks attributable to the polymerizable monomers was performed using a gas chromatography-mass spectrometer. The results revealed that almost all of the added methyl methacrylate, 2-ethylhexyl methacrylate and styrene had polymerized, confirming formation of the hydrophobic block B. Further, the weight average molecular weight of the pigment dispersing resin 9 measured using an HLC-8120GPC device manufactured by Tosoh Corporation was about 41,000. Furthermore, the acid value of the pigment dispersing resin 9 measured using an HLC-8120GPC device manufactured by Tosoh Corporation in accordance with method described above was 92 mgKOH/g.

(61) Subsequently, the reaction system was cooled to normal temperature, the mixed solution was then removed from the reaction container, and methyl ethyl ketone was used to adjust the solid fraction to 40.3%, thus obtaining a methyl ethyl ketone solution of the pigment dispersing resin 9.

(62) (2) Pigment Dispersions

(63) <Preparation Examples for Cyan Pigment Dispersions 1 to 7>

(64) Twenty parts of LIONOL BLUE 7358G (C.I. Pigment Blue 15:3) manufactured by Toyo Color Co., Ltd., 20 parts of the aqueous solution (solid fraction concentration: 30%) of the pigment dispersing resin 1 and 60 parts of water were mixed together and preliminary dispersed using a stirrer. Subsequently, the mixture was subjected to a main dispersion for two hours using a Dyno-Mill with a capacity of 0.6 L filled with 1,800 g of zirconia beads of diameter 0.5 mm, thus obtaining a cyan pigment dispersion 1. Further, with the exception of replacing the pigment dispersing resin 1 with each of the pigment dispersing resins 2 to 7, cyan pigment dispersions 2 to 7 were obtained in the same manner as the above cyan pigment dispersion 1.

(65) <Preparation Examples for Magenta Pigment Dispersions 1 to 7>

(66) With the exception of changing the pigment used to FASTGEN SUPER MAGENTA RG (C.I. Pigment Red 122) manufactured by DIC Corporation, magenta pigment dispersions 1 to 7 were obtained in the same manner as the preparation examples for the above cyan pigment dispersions 1 to 7.

(67) <Preparation Examples for Yellow Pigment Dispersions 1 to 7>

(68) With the exception of changing the pigment used to FAST YELLOW 7413 (C.I. Pigment Yellow 74) manufactured by Sanyo Color Works, Ltd., yellow pigment dispersions 1 to 7 were obtained in the same manner as the preparation examples for the above cyan pigment dispersions 1 to 7.

(69) <Preparation Examples for Black Pigment Dispersions 1 to 7>

(70) With the exception of changing the pigment used to PrinteX 85 (carbon black) manufactured by Orion Engineered Carbons S.A., black pigment dispersions 1 to 7 were obtained in the same manner as the preparation examples for the above cyan pigment dispersions 1 to 7.

(71) <Preparation Examples for Cyan Pigment Dispersions 8 and 9>

(72) A mixing container fitted with a stirrer was charged with 14.9 parts of the methyl ethyl ketone solution (solid fraction concentration: 40.3%) of the pigment dispersing resin 8 and 14 parts of methyl ethyl ketone, 50 parts of water and 0.45 parts of dimethylaminoethanol were then added under stirring, and the resulting mixture was stirred for a further 30 minutes. Subsequently, 20 parts of LIONOL BLUE 7358G (C.I. Pigment Blue 15:3) manufactured by Toyo Color Co., Ltd. was added as a pigment, and following thorough mixing (preliminary dispersion), a main dispersion was conducted for two hours using a Dyno-Mill with a capacity of 0.6 L filled with 1,800 g of zirconia beads of diameter 0.5 mm. The resulting dispersion was extracted, and following the addition of 15 parts of water, an evaporator was used to remove the methyl ethyl ketone by distillation under reduced pressure. The solid fraction concentration was then adjusted to 20% to obtain a cyan pigment dispersion 8.

(73) Furthermore, with the exceptions of replacing the methyl ethyl ketone solution of the pigment dispersing resin 8 with the methyl ethyl ketone solution of the pigment dispersing resin 9, and altering the amount added of the dimethylaminoethanol to 0.9 parts, a cyan pigment dispersion 9 was obtained in the same manner as the above preparation example for the cyan pigment dispersion 8.

(74) <Preparation Examples for Magenta Pigment Dispersions 8 and 9>

(75) With the exception of changing the pigment used to FASTGEN SUPER MAGENTA RG (C.I. Pigment Red 122) manufactured by DIC Corporation, magenta pigment dispersions 8 and 9 were obtained in the same manner as the above preparation examples for the cyan pigment dispersions 8 and 9.

(76) <Preparation Examples for Yellow Pigment Dispersions 8 and 9>

(77) With the exception of changing the pigment used to FAST YELLOW 7413 (C.I. Pigment Yellow 74) manufactured by Sanyo Color Works, Ltd., yellow pigment dispersions 8 and 9 were obtained in the same manner as the above preparation examples for the cyan pigment dispersions 8 and 9.

(78) <Preparation Examples for Black Pigment Dispersions 8 and 9>

(79) With the exception of changing the pigment used to PrinteX 85 (carbon black) manufactured by Orion Engineered Carbons S.A., black pigment dispersions 8 and 9 were obtained in the same manner as the above preparation examples for the cyan pigment dispersions 8 and 9.

(80) <Preparation Example for Cyan Pigment Dispersion 10>

(81) Twenty parts of LIONOL BLUE 7358G (C.I. Pigment Blue 15:3) manufactured by Toyo Color Co., Ltd., 24 parts of Plascoat Z-730 (a carboxyl group-containing polyester resin manufactured by GOO Chemical Co., Ltd., weight average molecular weight: 3,000, acid value: 50 mgKOH/g, solid fraction concentration: 25%) and 56 parts of water were mixed together and preliminary dispersed using a stirrer. Subsequently, the mixture was subjected to a main dispersion for two hours using a Dyno-Mill with a capacity of 0.6 L filled with 1,800 g of zirconia beads of diameter 0.5 mm, thus obtaining a cyan pigment dispersion 10.

(82) <Preparation Examples for Magenta Pigment Dispersion 10, Yellow Pigment Dispersion 10, and Black Pigment Dispersion 10>

(83) With the exception of changing the pigment used to FASTGEN SUPER MAGENTA RG (C.I. Pigment Red 122) manufactured by DIC Corporation, FAST YELLOW 7413 (C.I. Pigment Yellow 74) manufactured by Sanyo Color Works, Ltd., and PrinteX 85 (carbon black) manufactured by Orion Engineered Carbons S.A. respectively, a magenta pigment dispersion 10, yellow pigment dispersion 10 and black pigment dispersion 10 were obtained in the same manner as the above preparation example for the cyan pigment dispersion 10.

(84) (3) Binder Resin

(85) <Production Example for Joncryl 690 Varnish>

(86) The materials listed below were mixed together under constant stirring at room temperature for 30 minutes, and the mixture was then heated to 60° C. and stirred for a further three hours. Subsequently, the mixture was cooled to room temperature to obtain a Joncryl 690 varnish.

(87) (Materials)

(88) Joncryl 690 (an acrylic resin manufactured by BASF Corporation, weight average molecular weight: 16,500, acid value: 240 mgKOH/g) 20 parts

(89) Ion-exchanged water 80 parts

(90) (4) Inkjet Ink Sets

(91) <Production Example for CMYK Inkjet Ink Set 1>

(92) The materials listed below were added sequentially to a mixing container under constant stirring with a stirrer, and were mixed thoroughly until a uniform mixture was obtained. Subsequently, a filtration was performed using a membrane filter having a pore size of 1 μm to remove coarse particles that can cause inkjet head blockages, thus obtaining an ink.

(93) More specifically, by conducting the above step with each of the previously prepared cyan pigment dispersion 1, magenta pigment dispersion 1, yellow pigment dispersion 1 and black pigment dispersion 1, a cyan ink, magenta ink, yellow ink and black ink were obtained. Using these four color inks, a CMYK inkjet ink set 1 was produced.

(94) TABLE-US-00004 Pigment dispersion 1 30 parts (each of the previously prepared pigment dispersions 1 of cyan, magenta, yellow and black) Joncryl 8211 (an acrylic resin emulsion manufactured 13 parts by BASF Corporation, solid fraction: 44%) Diethylene glycol monoisopropyl ether (DEMiPE) 17 parts Diethylene glycol monobutyl ether (DEMBE) 10 parts Triethanolamine (TEA) 0.5 parts Surfynol 465 (an acetylene-based surfactant manufactured 1 part by Air Products and Chemicals, Inc., Griffin method HLB value = 13) PROXEL GXL 0.05 parts Ion-exchanged water 28.45 parts

(95) The viscosity of each of the obtained inks at 25° C. was measured using an ε-type viscometer (TVE25L viscometer, manufactured by Toki Sangyo Co., Ltd.). The average value of the viscosities of the cyan ink, magenta ink, yellow ink and black ink that constitute the above CMYK inkjet ink set 1 is shown in Table 3.

(96) Further, the weighted average boiling point for the water-soluble organic solvent shown in Table 3 represents the value for the weighted average boiling point at one atmosphere. This weighted average boiling point is a value obtained by calculating, for each water-soluble organic solvent, the product of the boiling point at one atmosphere and the mass ratio of that organic solvent relative to the total mass of all of the water-soluble organic solvents, and then adding together the calculated products for the various water-soluble organic solvents.

(97) <Production Examples for CMYK Inkjet Ink Sets 2 to 45>

(98) With the exception of using the materials shown below in Table 3, the same method as that described for the inkjet ink set 1 was used to obtain CMYK inkjet ink sets 2 to 45 (each composed of the four colors of C, M, Y, K). For each of these inkjet ink sets, the viscosity was measured and the weighted average boiling point of the water-soluble organic solvents at one atmosphere was determined in the same manner as described for the inkjet ink set 1. These results are shown in Table 3.

(99) TABLE-US-00005 TABLE 3 CMYK inkjet ink set 1 2 3 4 5 6 7 8 9 10 11 12 Blend Pigment dispersion Pigment 30 amount dispersion 1 (%) Pigment 30 dispersion 2 Pigment 30 dispersion 3 Pigment 30 30 dispersion 4 Pigment 30 dispersion 5 Pigment 30 dispersion 6 Pigment 30 dispersion 7 Pigment 30 dispersion 8 Pigment 30 dispersion 9 Pigment 30 dispersion 10 CABOJET 60 Binder resin Joncryl 8211 13 13 13 13 13 13 13 13 13 13 13 13 (solid fraction: 44%) Joncryl 690 varnish (solid fraction: 20%) Water- Organic DEMEE soluble solvent (boiling point: organic (A) 196° C.) solvent DEMiPE 17 17 17 17 17 17 17 17 17 17 16 22 (boiling point: 207° C.) DEMBE 10 10 10 10 10 10 10 10 10 10 9 12.5 (boiling point: 230° C.) DEMiBE (boiling point: 241° C.) TEMBE (boiling point: 278° C.) Other Glycerol organic (boiling point: solvent 290° C.) pH adjuster TEA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 NaOH Surfactant acetylene Surfynol 465 1 1 1 1 1 1 1 1 1 1 1 1 Preservative PROXEL 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 GXL Water 28.45 28.45 28.45 28.45 28.45 28.45 28.45 28.45 28.45 28.45 0.45 20.95 Total 100 100 100 100 100 100 100 100 100 100 100 100 Inkjet ink viscosity 8.0 7.7 7.5 7.4 7.9 8.3 7.1 8.0 7.8 7.3 7.4 7.7 Total amount of water-soluble 27.0 27.0 27.0 27.0 27.0 27.0 27.0 27.0 27.0 27.0 25.0 34.5 organic solvent (%) Blend amount of solvent (B) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 when blend amount of solvent (A) is deemed 1 Amount of water-soluble 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 organic solvent having boiling point of 245° C. or higher (%) Weighted average boiling 215.5 215.5 215.5 215.5 215.5 215.5 215.5 215.5 215.5 215.5 215.3 215.3 point of water-soluble organic solvents (° C.) CMYK inkjet ink set 13 14 15 16 17 18 19 20 21 22 23 Blend Pigment dispersion Pigment 30 30 30 30 30 30 30 amount dispersion 1 (%) Pigment dispersion 2 Pigment dispersion 3 Pigment 30 30 30 30 dispersion 4 Pigment dispersion 5 Pigment dispersion 6 Pigment dispersion 7 Pigment dispersion 8 Pigment dispersion 9 Pigment dispersion 10 CABOJET Binder resin Joncryl 8211 13 13 13 13 13 13 13 13 13 13 (solid fraction: 44%) Joncryl 690 28.6 varnish (solid fraction: 20%) Water- Organic DEMEE 17 3.5 3.5 soluble solvent (boiling point: organic (A) 196° C.) solvent DEMiPE 15 12.5 2.5 1.3 17 3.5 7 5.5 5.5 (boiling point: 207° C.) DEMBE 9 7.5 1.5 0.7 17 (boiling point: 230° C.) DEMiBE 13.5 (boiling point: 241° C.) TEMBE 10 8 8 (boiling point: 278° C.) Other Glycerol 10 organic (boiling point: solvent 290° C.) pH adjuster TEA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 NaOH 0.1 0.1 0.1 Surfactant acetylene Surfynol 465 1 1 1 1 1 1 1 1 1 1 1 Preservative PROXEL 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 GXL Water 31.45 35.45 51.45 53.45 38.45 28.85 38.45 38.45 38.45 38.85 23.25 Total 100 100 100 100 100 100 100 100 100 100 100 Inkjet ink viscosity 7.7 7.7 7.0 7.0 7.8 12.0 7.7 8.0 8.0 7.7 7.7 Total amount of water-soluble 34.5 24.0 20.0 4.0 2.0 17.0 10.0 17.0 17.0 13.5 13.5 organic solvent (%) Blend amount of solvent (B) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 when blend amount of solvent (A) is deemed 1 Amount of water-soluble 0.0 0.0 0.0 0.0 0.0 10.0 0.0 0.0 10.0 8.0 8.0 organic solvent having boiling point of 245° C. or higher (%) Weighted average boiling 215.6 215.6 215.6 215.1 207.0 230.8 230.0 234.0 248.8 238.1 238.1 point of water-soluble organic solvents (° C.) CMYK inkjet ink set 24 25 26 27 28 29 30 31 32 33 34 35 Blend Pigment dispersion Pigment amount dispersion 1 (%) Pigment 30 30 30 30 30 30 30 30 30 30 30 dispersion 5 Pigment 30 dispersion 9 Binder resin Joncryl 8211 13 13 13 13 13 13 13 13 13 13 13 13 (solid fraction: 44%) Joncryl 690 varnish (solid fraction: 20%) Water- Organic DEMEE soluble solvent (boiling point: organic (A) 196° C.) solvent DEMiPE 17 7 4.5 3.2 17 17 17 17 17 10 15 5 (boiling point: 207° C.) DEMBE (boiling point: 230° C.) Diol-based 1,2-PD 10 20 20 20 20 30 40 solvent (boiling point: (B) 188° C.) 1,3-PD 2.5 3.8 10 (boiling point: 214° C.) 1,3-BuD 10 (boiling point: 207° C.) DEG 2.5 10 (boiling point: 244° C.) 1,2-HexD 10 (boiling point: 224° C.) 1,5-PenD 10 (boiling point: 239° C.) Other TEMME organic (boiling point: solvent 249° C.) EMBE (boiling point: 171° C.) Glycerol (boiling point: 290° C.) pH adjuster TEA NaOH 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Surfact- acetylene Surfynol 465 1 1 1 1 1 1 1 1 1 1 1 1 ant Surfynol 104E siloxane BYK348 fluorine Zonyl FS-300 Preservative PROXEL 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 GXL Water 28.85 28.85 28.85 28.85 28.85 28.85 16.35 28.85 28.85 15.85 0.85 40.85 Total 100 100 100 100 100 100 100 100 100 100 100 100 Inkjet ink viscosity 8.0 8.0 8.0 7.9 7.8 8.3 9.5 8.8 8.6 7.8 7.9 10.1 Total amount of water-soluble 27.0 27.0 27.0 27.0 27.0 27.0 39.5 27.0 27.0 40.0 55.0 15.0 organic solvent (%) Blend amount of solvent (B) 0.6 2.9 5.0 7.4 0.6 0.6 1.3 0.6 0.6 3.0 2.7 2.0 when blend amount of solvent (A) is deemed 1 Amount of water-soluble 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 organic solvent having boiling point of 245° C. or higher (%) Weighted average boiling 200.0 192.9 193.6 193.9 209.6 207.0 199.7 213.3 218.9 192.8 193.2 231.7 point of water-soluble organic solvents (° C.) CMYK inkjet ink set 36 37 38 39 40 41 42 43 44 45 Blend Pigment dispersion Pigment 30 30 30 30 30 30 amount dispersion 1 (%) Pigment dispersion 5 Pigment 30 30 30 30 dispersion 9 Binder resin Joncryl 8211 13 13 13 13 13 13 13 13 13 13 (solid fraction: 44%) Joncryl 690 varnish (solid fraction: 20%) Water- Organic DEMEE soluble solvent (boiling point: organic (A) 196° C.) solvent DEMiPE 6 17 17 17 17 (boiling point: 207° C.) DEMBE 2 5 17 10 10 (boiling point: 230° C.) Diol-based 1,2-PD 10 solvent (boiling point: (B) 188° C.) 1,3-PD (boiling point: 214° C.) 1,3-BuD (boiling point: 207° C.) DEG 10 (boiling point: 244° C.) 1,2-HexD (boiling point: 224° C.) 1,5-PenD (boiling point: 239° C.) Other TEMME 10 17 organic (boiling point: solvent 249° C.) EMBE 17 (boiling point: 171° C.) Glycerol 12 20 7 (boiling point: 290° C.) pH adjuster TEA 1 1 1 1 0.5 0.5 0.5 0.5 0.5 0.5 NaOH Surfact- acetylene Surfynol 465 1 1 1 1 ant Surfynol 104E 1 1 0.5 siloxane BYK348 1 fluorine Zonyl FS-300 2.5 Preservative PROXEL 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 GXL Water 34.95 37.95 19.95 28.45 28.45 26.95 38.45 38.45 38.45 39.45 Total 100 100 100 100 100 100 100 100 100 100 Inkjet ink viscosity 7.8 7.3 7.5 7.8 7.9 7.9 7.5 8.0 8.1 7.5 Total amount of water-soluble 20.0 17.0 35.0 27.0 27.0 27.0 17.0 17.0 17.0 17.0 organic solvent (%) Blend amount of solvent (B) 0.0 0.0 2.0 0.0 0.0 0.0 — — — 0.0 when blend amount of solvent (A) is deemed 1 Amount of water-soluble 12.0 0.0 20.0 10.0 0.0 0.0 7.0 0.0 17.0 0.0 organic solvent having boiling point of 245° C. or higher (%) Weighted average boiling 259.1 207.0 268.3 237.0 215.5 215.5 230.0 171.0 249.0 207.0 point of water-soluble organic solvents (° C.)

(100) Of the materials shown in Table 3, details regarding the materials and abbreviations not used in Table 1 or the above description are as follows.

(101) <1> Pigment Dispersions

(102) CABOJET:

(103) Cyan: Cabojet 250C (a self-dispersing copper phthalocyanine pigment dispersion, manufactured by Cabot Corporation, pigment concentration: 10%)

(104) Magenta: Cabojet 265M (a self-dispersing magenta pigment dispersion, manufactured by Cabot Corporation, pigment concentration: 10%)

(105) Yellow: Cabojet 270 (a self-dispersing yellow pigment dispersion, manufactured by Cabot Corporation, pigment concentration: 10%)

(106) Black: Cabojet 200 (a self-dispersing carbon black aqueous solution, manufactured by Cabot Corporation, pigment concentration: 20%) was diluted with an equal volume of water to adjust the pigment concentration to 10%

(107) <2> Specified Glycol Ether-Based Organic Solvents (A)

(108) DEMEE: diethylene glycol monoethyl ether (boiling point: 196° C.)

(109) DEMiPE: diethylene glycol monoisopropyl ether (boiling point: 207° C.)

(110) DEMBE: diethylene glycol monobutyl ether (boiling point: 230° C.)

(111) DEMiBE: diethylene glycol monoisobutyl ether (boiling point: 241° C.)

(112) TEMBE: triethylene glycol monobutyl ether (boiling point: 278° C.)

(113) <3> Diol-Based Solvent (B) of Specified Surface Tension

(114) 1,3-PD: 1,3-propanediol (boiling point: 214° C., surface tension: 47.1 mN/m)

(115) 1,3-BuD: 1,3-butanediol (boiling point: 207° C., surface tension: 37.1 mN/m)

(116) 1,5-PenD: 1,5-pentanediol (boiling point: 239° C., surface tension: 42.2 mN/m)

(117) <4> Other Organic Solvents

(118) TEMME: triethylene glycol monomethyl ether (boiling point: 249° C.)

(119) EMBE: ethylene glycol monobutyl ether (boiling point: 171° C.)

(120) <Surfactant>

(121) Zonyl FS-300: a fluorine-based surfactant manufactured by E. I. du Pont de Nemours and Company (solid fraction concentration: 40%, Griffin method HLB value=14)

III. Evaluations of Treatment Liquids and Inkjet Inks

(122) (1) Production Examples for Recording Media with Applied Treatment Liquid

(123) <Production Example for Recording Medium 1a with Applied Treatment Liquid>

(124) Using a print tester Flexiproof 100 (manufactured by Matsuo Sangyo Co., Ltd.), the treatment liquid 1 prepared in the manner described above was coated uniformly onto UPM Finesse gloss paper (manufactured by UPM Corporation, grammage: 115 g/m.sup.2, referred to as “recording medium A” in the subsequent description and Tables 4 to 6). The coating was performed using a ceramic roller having 140 ridges/inch at a speed of 80 m/min, so as to achieve a coating film thickness of the treatment liquid 1 of 3.0±0.3 μm. Following application of the treatment liquid 1 in the manner described above, the UPM Finesse gloss paper was dried for three minutes in a 50° C. air oven, thus completing production of a recording medium 1a with the applied treatment liquid.

(125) <Production Examples for Recording Media 2a to 35a and 48a to 53a with Applied Treatment Liquids>

(126) Using the same method as the recording medium 1a with the applied treatment liquid, recording media 2a to 35a and 48a to 53a each with an applied treatment liquid were produced using the treatment liquids shown in Table 4.

(127) <Production Example for Recording Medium 36a with Applied Treatment Liquid>

(128) With the exceptions of using the treatment liquid 3 prepared above, using the print tester Flexiproof 100 with a ceramic roller having 1,000 ridges/inch, and performing the coating so as to achieve a coating film thickness of the treatment liquid 3 of 0.4±0.1 μm, a recording medium 36a with an applied treatment liquid was produced in the same manner as the recording medium 1a with an applied treatment liquid.

(129) <Production Example for Recording Medium 37a with Applied Treatment Liquid>

(130) Following production of the recording medium 3a with an applied treatment liquid, a print tester Flexiproof 100 with a ceramic roller having 140 ridges/inch was used to apply a second coating of the treatment liquid 3 to the surface already coated with the treatment liquid 3. The recording medium was then dried for three minutes in a 50° C. air oven. This process was repeated a further two times to produce a recording medium 37a with an applied treatment liquid in which the total wet coating film thickness of the treatment liquid 3 was 12.0±1.2 μm.

(131) <Production Examples for Recording Media 38a to 42a and 54a with Applied Treatment Liquids>

(132) With the exceptions of using the treatment liquids 2, 3, 5, 8, 19 and 36, and using Npi high-quality paper 45 (manufactured by Nippon Paper Industries Co., Ltd., grammage: 52.3 g/m.sup.2, referred to as “recording medium B” in the subsequent description and Tables 4 to 6) as the recording medium, recording media 38a to 42a and 54a with applied treatment liquids were produced in the same manner as the recording medium 1a with an applied treatment liquid.

(133) <Production Examples for Recording Medium 43a to 47a with Applied Treatment Liquids>

(134) With the exceptions of using the treatment liquids 2, 3, 5, 8 and 19, and using Craft Reproliner (manufactured by Oji F-Tex C., Ltd., ream weight: 146 kg, referred to as “recording medium C” in the subsequent description and Tables 4 to 6) as the recording medium, recording media 43a to 47a with applied treatment liquids were produced in the same manner as the recording medium 1a with an applied treatment liquid.

(135) TABLE-US-00006 TABLE 4 Recording medium with applied Amount of treatment Treatment Recording Coating film calcium liquid liquid No. medium thickness (μm) ions (mmol/m.sup.2)  1a 1 A 3.0 1.2  2a 2 A 3.0 1.4  3a 3 A 3.0 2.5  4a 4 A 3.0 3.2  5a 5 A 3.0 3.6  6a 6 A 3.0 3.8  7a 7 A 3.0 2.5  8a 8 A 3.0 2.5  9a 9 A 3.0 2.5 10a 10 A 3.0 2.5 11a 11 A 3.0 2.5 12a 12 A 3.0 2.5 13a 13 A 3.0 2.5 14a 14 A 3.0 2.5 15a 15 A 3.0 2.5 16a 16 A 3.0 2.5 17a 17 A 3.0 2.5 18a 18 A 3.0 2.5 19a 19 A 3.0 2.5 20a 20 A 3.0 2.5 21a 21 A 3.0 2.5 22a 22 A 3.0 2.5 23a 23 A 3.0 2.5 24a 24 A 3.0 2.5 25a 25 A 3.0 2.5 26a 26 A 3.0 2.5 27a 27 A 3.0 2.5 28a 28 A 3.0 2.5 29a 29 A 3.0 2.5 30a 30 A 3.0 2.5 31a 31 A 3.0 2.5 32a 32 A 3.0 2.5 33a 33 A 3.0 2.5 34a 34 A 3.0 2.5 35a 35 A 3.0 2.5 36a 3 A 0.4 0.3 37a 3 A 12.0 10.2 38a 2 B 3.0 1.4 39a 3 B 3.0 2.5 40a 5 B 3.0 3.6 41a 8 B 3.0 2.5 42a 19 B 3.0 2.5 43a 2 C 3.0 1.4 44a 3 C 3.0 2.5 45a 5 C 3.0 3.6 46a 8 C 3.0 2.5 47a 19 C 3.0 2.5 48a 36 A 3.0 2.1 49a 37 A 3.0 0.0 50a 38 A 3.0 1.0 51a 39 A 3.0 4.0 52a 40 A 3.0 2.5 53a 41 A 3.0 2.5 54a 36 B 3.0 2.1
(2) Evaluation of Treatment Liquid Coating Irregularities
<Evaluation of Treatment liquid Coating Irregularities (Initial)>

(136) In order to enhance the visibility, 0.1 g of Kayafect Red P Liquid (manufactured by Nippon Kayaku Co., Ltd.) was added to 9.9 g samples of each of the treatment liquids 1 to 35 produced above. These samples were then each mixed thoroughly to dissolve the dye, thus obtaining colored treatment liquids 1 to 35.

(137) Using a Flexiproof 100 (manufactured by Matsuo Sangyo Co., Ltd.), each of these colored treatment liquids was coated uniformly onto the recording medium shown below in Table 5. The coating of the colored treatment liquid was performed using a ceramic roller having 140 ridges/inch at a speed of 80 m/min, so as to achieve a coating film thickness of the treatment liquid 1 of 3.0±0.3 μm. Following application of the colored treatment liquid, the recording medium was dried for three minutes in a 50° C. air oven, thus completing production of a recording media 1b to 45b each with an applied colored treatment liquid.

(138) The level of treatment liquid coating irregularities (the initial coating applicability) was evaluated by continuously producing 10 copies of each recording medium with an applied colored treatment liquid using the method described above, and visually inspecting each recording medium for color irregularities. The evaluation criteria were as follows, with evaluations of A and B deemed to represent a good level of coating irregularities for the treatment liquid.

(139) (Evaluation Criteria)

(140) A: absolutely no coating irregularities observed in any of the 10 copies.

(141) B: coating irregularities observed in one or two of the 10 copies.

(142) C: coating irregularities observed in at least three of the 10 copies.

(143) <Evaluation of Treatment Liquid Coating Irregularities (after Aging)>

(144) Ten kg of each of the above treatment liquids 1 to 35 was placed in an 18-liter drum, and with the drum unsealed in an open state, the drum was left to stand for one week at room temperature. Subsequently, the solid fraction concentration of each treatment liquid was measured, and if the measured value was greater than that prior to the standing period, then water was added to adjust the solid fraction concentration to the same as that prior to standing, thereby completing preparation of aged treatment liquids 1 to 35.

(145) Using the above aged treatment liquids 1 to 35, aged colored treatment liquids 1 to 35 were prepared using the same method as that described above in the evaluation method for treatment liquid coating irregularities. Recording media 1c to 45 with these applied aged colored treatment liquids were then produced, and the level of treatment liquid coating irregularities after aging (the coating applicability after aging) was evaluated. The same evaluation criteria as those described above were used.

(146) The evaluation results for the above coating irregularities are shown in Table 5.

(147) TABLE-US-00007 TABLE 5 Recording medium used Recording Recording medium with medium with Treatment liquid applied applied aged coating colored colored irregularities treatment treatment Treatment Recording After liquid liquid liquid No. medium Initial aging  1b  1c 1 A A A  2b  2c 2 A A A  3b  3c 3 A A A  4b  4c 4 A A A  5b  5c 5 A A A  6b  6c 6 A A A  7b  7c 7 A A A  8b  8c 8 A A A  9b  9c 9 A A A 10b 10c 10 A A A 11b 11c 11 A A A 12b 12c 12 A A A 13b 13c 13 A A B 14b 14c 14 A A B 15b 15c 15 A A B 16b 16c 16 A A B 17b 17c 17 A A A 18b 18c 18 A A A 19b 19c 19 A A A 20b 20c 20 A A B 21b 21c 21 A A A 22b 22c 22 A A A 23b 23c 23 A A A 24b 24c 24 A A A 25b 25c 25 A A A 26b 26c 26 A A A 27b 27c 27 A A A 28b 28c 28 A A A 29b 29c 29 A A A 30b 30c 30 A A B 31b 31c 31 A A A 32b 32c 32 A B B 33b 33c 33 A A A 34b 34c 34 A A A 35b 35c 35 A B B 36b 36c 2 B A A 37b 37c 3 B A A 38b 38c 5 B A A 39b 39c 8 B A A 40b 40c 19 B A A 41b 41c 2 C A A 42b 42c 3 C A A 43b 43c 5 C A A 44b 44c 8 C A A 45b 45c 19 C A B

IV. Evaluation of Ink Sets

Examples 1 to 87, Comparative Examples 1 to 12

(148) (1) Preparation of Inkjet Ink Set Printing Apparatus

(149) Four inkjet heads KJ4B-1200 (manufactured by Kyocera Corporation) were installed above a conveyor capable of transporting a recording medium, and the K, C, M and Y inkjet inks that constitute an inkjet ink set were used to fill these heads in sequence from the upstream side. The design resolution of these inkjet heads is 1,200 dpi, the maximum drive frequency is 64 kHz, and the recording resolution in the recording medium transport direction during printing at the maximum drive frequency and a printing speed of 80 m/min is 1,200 dpi.

(150) (2) Production of Printed Matter

(151) <Printing of Bicycle Image Printed Matter>

(152) Each of the recording media with an applied treatment liquid produced in the manner described above was secured to the conveyor of the aforementioned inkjet ink set printing apparatus, and the conveyor was driven at a fixed speed listed below. On the other hand, as the recording medium with the applied treatment liquid passed beneath the installed location of the inkjet heads, the inkjet inks were jetted onto the recording medium in KCMY order using a drop volume of 3 pL to print a natural image N5 (bicycle) from the high-precision color digital standard image data (CMYK/SCID) prescribed in JIS X 9201. Within 10 seconds of the completion of printing, the printed matter was fed into a 50° C. air oven and dried for three minutes, thus obtaining a bicycle image printed item. The above conveyor speed was set to one of three speeds: 40 m/min, 60 m/min and 80 m/min, with printing conducted under each of these conditions to obtain printed items.

(153) <Printing of Solid Printed Matter>

(154) Each of the recording media with an applied treatment liquid produced in the manner described above was secured to the conveyor of the aforementioned inkjet ink set printing apparatus, and the conveyor was driven at a fixed speed listed below. On the other hand, as the recording medium with the applied treatment liquid passed beneath the installed location of the inkjet heads, the KCMY inkjet inks were jetted onto the recording medium using a drop volume of 3 pL to print an image in which 3 cm×3 cm solid printing portions with a print ratio of 100% were arranged adjacent to one another in CMYK order. Within 10 seconds of the completion of printing, the printed matter was fed into a 50° C. air oven and dried for a fixed period of time, thus obtaining solid printed matter.

(155) In the coverage evaluation described below, the printed matter that was used was obtained by setting the conveyor speed to one of three speeds: 40 m/min, 60 m/min and 80 m/min, and using a drying time in the 50° C. air oven of three minutes. In the drying properties evaluation, printing was performed at a conveyor speed of 60 m/min, and solid printed items that had been removed from the 50° C. air oven after periods of time that were increased in 30-second intervals were used.

(156) The various combinations of recording media and inkjet inks used in producing the above printed matter were as shown below in Table 6.

(157) (3) Evaluations of Printed Matter

(158) The bicycle image printed matter and the solid printed matter produced above were subjected to each of the evaluations described below. The evaluation results obtained are shown below in Table 6.

(159) TABLE-US-00008 TABLE 6 Recording medium with applied treatment liquid Recording medium Recording with medium applied Evaluation results with aged Coating Initial applied colored film CMYK After Coating treatment treatment Treatment Recording thickness inkjet Initial aging Drying film liquid liquid liquid No. medium (μm) ink set Aggregation Coverage Coverage properties durability Example 1  1a  1d 1 A 3.0 1 C A A A C Example 2  2a  2d 2 A 3.0 1 B A A A B Example 3  3a  3d 3 A 3.0 1 A A A A A Example 4  4a  4d 4 A 3.0 1 A A A A A Example 5  5a  5d 5 A 3.0 1 A A B A B Example 6  6a  6d 6 A 3.0 1 B B C A C Example 7  7a  7d 7 A 3.0 1 A A A A A Example 8  8a  8d 8 A 3.0 1 B A A A B Example 9  9a  9d 9 A 3.0 1 C A A B C Example 10 10a 10d 10 A 3.0 1 B A A A B Example 11 11a 11d 11 A 3.0 1 B A A A B Example 12 12a 12d 12 A 3.0 1 B A A A B Example 13 13a 13d 13 A 3.0 1 A B B A B Example 14 14a 14d 14 A 3.0 1 A A B A A Example 15 15a 15d 15 A 3.0 1 A A A A A Example 16 16a 16d 16 A 3.0 1 A A B A B Example 17 17a 17d 17 A 3.0 1 A A A A A Example 18 18a 18d 18 A 3.0 1 A A A A A Example 19 19a 19d 19 A 3.0 1 A A B A A Example 20 20a 20d 20 A 3.0 1 A A B A A Example 21 21a 21d 21 A 3.0 1 A A A A A Example 22 22a 22d 22 A 3.0 1 A A A A A Example 23 23a 23d 23 A 3.0 1 A A A A B Example 24 24a 24d 24 A 3.0 1 A A A A A Example 25 25a 25d 25 A 3.0 1 B A A A B Example 26 26a 26d 26 A 3.0 1 C A A A C Example 27 27a 27d 27 A 3.0 1 A A A A A Example 28 28a 28d 28 A 3.0 1 A A B A B Example 29 29a 29d 29 A 3.0 1 A A A A A Example 30 30a 30d 30 A 3.0 1 A A A A B Example 31 31a 31d 31 A 3.0 1 A A A A B Example 32 32a 32d 32 A 3.0 1 A A A A B Example 33 33a 33d 33 A 3.0 1 A A A A A Example 34 34a 34d 34 A 3.0 1 A A A A A Example 35 35a 35d 35 A 3.0 1 A A A A A Example 36 36a 36d 3 A 0.4 1 C A A A B Example 37 37a 37d 3 A 12.0 1 A B B A B Example 38 38a 38d 2 B 3.0 1 B A A A B Example 39 39a 39d 3 B 3.0 1 A A A A B Example 40 40a 40d 5 B 3.0 1 B B B A B Example 41 41a 41d 8 B 3.0 1 B A A A C Example 42 42a 42d 19 B 3.0 1 A A B A B Example 43 43a 43d 2 C 3.0 1 B A A A B Example 44 44a 44d 3 C 3.0 1 A A A A B Example 45 45a 45d 5 C 3.0 1 B B B A B Example 46 46a 46d 8 C 3.0 1 B A A A C Example 47 47a 47d 19 C 3.0 1 A A B A B Example 48  2a  2d 2 A 3.0 2 B A A A B Example 49  2a  2d 2 A 3.0 3 B A A A B Example 50  2a  2d 2 A 3.0 4 B B B A B Example 51  2a  2d 2 A 3.0 5 C B C A B Example 52  2a  2d 2 A 3.0 6 C B B A B Example 53  2a  2d 2 A 3.0 7 C A A A B Example 54  2a  2d 2 A 3.0 8 B B B A B Example 55  2a  2d 2 A 3.0 9 B A A A B Example 56  2a  2d 2 A 3.0 10 C B B A B Example 57  2a  2d 2 A 3.0 11 C A A A C Example 58  2a  2d 2 A 3.0 12 B B B A C Example 59  2a  2d 2 A 3.0 13 A A A A A Example 60  2a  2d 2 A 3.0 14 A A A A A Example 61  2a  2d 2 A 3.0 15 A A A A A Example 62  2a  2d 2 A 3.0 16 B B B A C Example 63  2a  2d 2 A 3.0 17 B A A A B Example 64  2a  2d 2 A 3.0 18 B B B B C Example 65  2a  2d 2 A 3.0 19 B A A A B Example 66  2a  2d 2 A 3.0 20 A A A A B Example 67  2a  2d 2 A 3.0 21 B A A C B Example 68  2a  2d 2 A 3.0 22 B A A B B Example 69  2a  2d 2 A 3.0 23 B A A C B Example 70  2a  2d 2 A 3.0 24 B B B A B Example 71  2a  2d 2 A 3.0 25 A A A A B Example 72  2a  2d 2 A 3.0 26 B A B A B Example 73  2a  2d 2 A 3.0 27 B B B A B Example 74  2a  2d 2 A 3.0 28 B B B A B Example 75  2a  2d 2 A 3.0 29 B B B A B Example 76  2a  2d 2 A 3.0 30 B A A A B Example 77  2a  2d 2 A 3.0 31 B B B A B Example 78  2a  2d 2 A 3.0 32 B B B A B Example 79  2a  2d 2 A 3.0 33 A A A A B Example 80  2a  2d 2 A 3.0 34 A B B A B Example 81  2a  2d 2 A 3.0 35 A B B B B Example 82  2a  2d 2 A 3.0 36 C A A B C Example 83  2a  2d 2 A 3.0 37 B A A A B Example 84  2a  2d 2 A 3.0 38 B A A C C Example 85  2a  2d 2 A 3.0 39 B A A A B Example 86  2a  2d 2 A 3.0 40 C A A A B Example 87  2a  2d 2 A 3.0 41 B A A A B Comparative — — — A — 1 D D — D D Example 1 Comparative 48a 48d 36 A 3.0 1 B D — D C Example 2 Comparative Example 3 49a 49d 37 A 3.0 1 D B — D B Comparative 50a 50d 38 A 3.0 1 D A — A D Example 4 Comparative 51a 51d 39 A 3.0 1 B D — A D Example 5 Comparative 52a 52d 40 A 3.0 1 D A — C C Example 6 Comparative 53a 53d 41 A 3.0 1 D A — D D Example 7 Comparative 54a 54d 36 B 3.0 1 C D — C D Example 8 Comparative  2a  2d 2 A 3.0 42 D C — C D Example 9 Comparative  2a  2d 2 A 3.0 43 D D — C C Example 10 Comparative  2a  2d 2 A 3.0 44 D C — D D Example 11 Comparative  2a  2d 2 A 3.0 45 D C — A C Example 12 In the table, “—” indicates that the evaluation was not performed
<Evaluation of Aggregation Properties (Color Mixing)>

(160) Using a microscope, the dot shape of the 4C (CMYK) printed portion of the above bicycle image printed item was inspected at a magnification of 200× to evaluate the aggregation properties. The evaluation criteria were as follows, with evaluations of A, B and C deemed to indicate good aggregation properties.

(161) (Evaluation Criteria)

(162) A: at all three printing speeds, the dots in the 4C printed portion remained independent and no color mixing was observed.

(163) B: at 40 m/min and 60 m/min, the dots in the 4C printed portion remained independent and no color mixing was observed, but at 80 m/min, color mixing of the dots was observed.

(164) C: at 40 m/min, the dots in the 4C printed portion remained independent and no color mixing was observed, but at 60 m/min and 80 m/min, color mixing of the dots was observed.

(165) D: at all three printing speeds, color mixing of the dots in the 4C printed portion was observed.

(166) <Evaluation of Coverage (Initial)>

(167) Using a microscope, the solid printed matter described above was inspected at a magnification of 200×, and for each color, an evaluation was made as to whether voids were absent and banding was absent. The evaluation criteria were as follows, with evaluations of A, B and C deemed to indicate good coverage. The evaluation result recorded in Table 6 represents the worst evaluation result among the four colors.

(168) (Evaluation Criteria)

(169) A: at all three printing speeds, neither voids nor banding was observed.

(170) B: at 40 m/min and 60 m/min, neither voids nor bands were observed, but at 80 m/min, voids or bands were observed.

(171) C: at 40 m/min, neither voids nor bands were observed, but at 60 m/min and 80 m/min, voids or bands were observed.

(172) D: at all three printing speeds, voids or bands were observed.

(173) <Evaluation of Drying Properties>

(174) The drying properties of the printed matter were evaluated by using a finger to touch solid printed items that had been removed from the 50° C. air oven after periods of time that were increased in 30-second intervals. The evaluation criteria were as follows, with evaluations of A, B and C deemed to indicate good drying properties.

(175) (Evaluation Criteria)

(176) A: even when touched with a finger after 30 seconds in the oven, no ink adhered to the finger.

(177) B: ink adhered to the finger when touched after 30 seconds in the oven, but no ink adhered after one minute in the oven.

(178) C: ink adhered to the finger when touched after one minute in the oven, but no ink adhered after one minute and 30 seconds in the oven.

(179) D: ink adhered to the finger even when touched after one minute and 30 seconds in the oven.

(180) <Evaluation of Coating Film Durability>

(181) The bicycle image printed item described above was installed in a Sutherland Rub Tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.) fitted with a rubbing target paper (NPI-70, manufactured by Nippon Paper Industries Co., Ltd.), 4 pounds of weight was applied, and following a prescribed number of back and forth rubbing repetitions, the coating film durability was evaluated by inspecting the printed item visually to ascertain whether the ink had been rubbed off to expose the substrate. The evaluation criteria were as follows, with evaluations of A, B and C deemed to indicate practically usable levels.

(182) (Evaluation Criteria)

(183) A: even after 20 back and forth rubbing repetitions, the ink remained and the substrate was not visible.

(184) B: after 20 back and forth rubbing repetitions, the ink had rubbed off and the substrate was visible, but after 15 back and forth repetitions, the substrate was not visible.

(185) C: after 15 back and forth rubbing repetitions, the ink had rubbed off and the substrate was visible, but after 10 back and forth repetitions, the substrate was not visible.

(186) D: the ink had rubbed off and the substrate was visible even after 10 back and forth rubbing repetitions.

(187) (4) Evaluation of Ink Sets after Aging

(188) <Production of Aged Ink Sets>

(189) Ten kg of each of the above treatment liquids 1 to 41 and each of the CMYK inkjet ink sets 1 to 45 was placed in an 18-liter drum, and with the drum unsealed in an open state, the drum was left to stand for one week at room temperature. Subsequently, the solid fraction concentration of each treatment liquid and each inkjet ink was measured, and if the measured value was greater than that prior to the standing period (the initial value), then water was added to adjust the solid fraction concentration to the same as that prior to standing, thus completing preparation of aged treatment liquids 1 to 41 and aged CMYK inkjet ink sets 1 to 45.

(190) <Evaluation of Coverage (after Aging)>

(191) Using the above aged treatment liquids 1 to 41, the same method as that described above was used to produce recording media id to 54d with the applied aged treatment liquids. Further, using these recording media Id to 54d with the applied aged treatment liquids and the aged CMYK inkjet ink sets 1 to 45 described above, the same method as that described above for evaluating the coverage was used to evaluated the coverage after aging. The evaluation criteria were the same as described above. The evaluation results are shown in Table 6.

(192) <Evaluation of Jetting Stability of Inkjet Inks>

(193) Using the method described below, each of the aged CMYK inkjet ink sets 1 to 41 produced in the manner described above was used to evaluate the jetting stability simulating the state following a long run.

(194) First, an inkjet jetting apparatus fitted with four inkjet heads KJ4B-1200 (manufactured by Kyocera Corporation) was prepared, and the K, C, M and Y inkjet inks that constitute the aged CMYK inkjet ink set were used to fill these heads in sequence from the upstream side. Then, under conditions including a drop volume of 3 pl and a drive frequency of 64 kHz, ink was jetted continuously from all of the nozzles for two hours. Subsequently, a nozzle check pattern was printed, and the jetting stability was evaluated by counting the number of missing nozzles. The evaluation criteria were as follows, with evaluations of A, B and C deemed to indicate favorable jetting stability. The valuation results obtained are shown in Table 7.

(195) (Evaluation Criteria)

(196) A: in the nozzle check pattern printed 2 hours after starting printing, there were no missing nozzles.

(197) B: in the nozzle check pattern printed 2 hours after starting printing, there were 1 or 2 missing nozzles.

(198) C: in the nozzle check pattern printed 2 hours after starting printing, there were 3 or 4 missing nozzles.

(199) D: in the nozzle check pattern printed 2 hours after starting printing, there were 5 or more missing nozzles.

(200) TABLE-US-00009 TABLE 7 Evaluation results CMYK inkjet ink set Jetting stability 1 A 2 A 3 A 4 A 5 B 6 A 7 A 8 A 9 A 10 A 11 A 12 A 13 A 14 A 15 A 16 A 17 A 18 A 19 A 20 A 21 B 22 B 23 A 24 A 25 A 26 A 27 A 28 A 29 A 30 A 31 A 32 A 33 A 34 A 35 A 36 A 37 A 38 A 39 A 40 A 41 C

(201) Based on the above results, it is evident that by using an ink set of the present invention, printed matter of high image quality, with excellent coating film durability and drying properties, and good suppression of image defects such as color mixing and insufficient coverage, can be provided regardless of the recording medium and the printing conditions such as the printing speed and recording resolution.