Non-aqueous inkjet ink composition

Abstract

An object is to provide a non-aqueous inkjet ink composition which offers excellent fine print reproducibility, solid fill property, and anti-mottling property on printed matters, even when it is printed, at high speed, on materials whose printing surface is constituted by a polyvinyl chloride polymer, ethylene-vinyl acetate copolymer, or other vinyl polymer, etc., and which also offers excellent rub resistance, solvent resistance, discharge stability, and resolubility of dried coating film, and has a high flash point. To achieve the object, a non-aqueous inkjet ink composition is provided which contains an acrylic resin, a ketone resin, a pigment, and a pigment dispersant, as well as propylene carbonate and diethylene glycol alkyl ether as an organic solvent.

Claims

1. A non-aqueous inkjet ink composition containing an acrylic resin, a ketone resin, a pigment, and a pigment dispersant, and also containing propylene carbonate and diethylene glycol dialkyl ether as an organic solvent, wherein, in the ink composition, the propylene carbonate is contained by 5 to 25 percent by mass, and the diethylene glycol dialkyl ether is contained at a ratio of the diethylene glycol dialkyl ether to the propylene carbonate by mass, which ratio is 3.0 to 8.0, wherein the acrylic resin and the ketone resin are contained at an acrylic resin/ketone resin ratio by mass of 3.0 to 20.0.

2. The non-aqueous inkjet ink composition according to claim 1, wherein the diethylene glycol dialkyl ether is diethylene glycol ethyl methyl ether and/or diethylene glycol diethyl ether.

3. The non-aqueous inkjet ink composition according to claim 1, wherein the acrylic resin is contained by 1 to 15 percent by mass in the ink composition.

4. The non-aqueous inkjet ink composition according to claim 1, wherein the ketone resin is contained by 0.1 to 10 percent by mass in the ink composition.

5. The non-aqueous inkjet ink composition according to claim 2, wherein the acrylic resin is contained by 1 to 15 percent by mass in the ink composition.

6. The non-aqueous inkjet ink composition according to claim 2, wherein the ketone resin is contained by 0.1 to 10 percent by mass in the ink composition.

7. The non-aqueous inkjet ink composition according to claim 3, wherein the ketone resin is contained by 0.1 to 10 percent by mass in the ink composition.

Description

EXAMPLES

(1) The following explains the present invention in greater detail by citing examples; however, the present invention is not limited to these examples. It should be noted that, unless otherwise specified, % and part indicate percent by mass and part by mass, respectively.

(2) The materials used in the Examples and Comparative Examples described below are as follows.

(3) <Pigment Dispersants>

(4) SOLSPERSE 39000 (manufactured by Lubrizol)

(5) SOLSPERSE 56000 (manufactured by Lubrizol)

(6) PB822: AJISPER PB822 (manufactured by Ajinomoto Fine-Techno)

(7) <Pigments>

(8) MA7: Carbon Black MA7 (manufactured by Mitsubishi Chemical)

(9) D7110F: HELIOGEN Blue D7110F (manufactured by BASF)

(10) G01: LEVASCREEN Yellow G01 (manufactured by LANXESS)

(11) RGT: FASTOGEN Super Magenta RGT (manufactured by DIC)

(12) <Acrylic Resins>

(13) BR-83: DIANAL BR-83 (manufactured by Mitsubishi Rayon, grass transition temperature 105 C., mass average molecular weight 40,000)

(14) BR-87: DIANAL BR-87 (manufactured by Mitsubishi Rayon, grass transition temperature 105 C., mass average molecular weight 25,000)

(15) BR-60: DIANAL BR-60 (manufactured by Mitsubishi Rayon, grass transition temperature 75 C., mass average molecular weight 70,000)

(16) BR-106: DIANAL BR-106 (manufactured by Mitsubishi Rayon, grass transition temperature 50 C., mass average molecular weight 60,000)

(17) <Ketone Resins>

(18) SK: TEGO VariPlus SK (manufactured by Evonik Japan, aromatic ketone-formaldehyde condensed hydrogenated ketone resin)

(19) AP: TEGO VariPlus AP (manufactured by Evonik Japan, aromatic ketone-formaldehyde condensed ketone resin)

Examples 1 to 18 and Comparative Examples 1 and 2

(20) (Manufacturing of Base Inks of Different Colors>

(21) <Manufacturing of Non-Aqueous Inkjet Base Black Ink>

(22) After dissolving 10 parts of a pigment dispersant (SOLSPERSE 39000) in 65 parts of diethylene glycol diethyl ether, and further mixing in 25 parts of a pigment (MA7) under agitation, the mixture was kneaded using a bead mill, to obtain a non-aqueous inkjet base blank ink.

(23) <Manufacturing of Non-Aqueous Inkjet Base Cyan Ink>

(24) After dissolving 10 parts of a pigment dispersant (SOLSPERSE 56000) in 65 parts of diethylene glycol diethyl ether, and further mixing in 25 parts of a pigment (D7110F) under agitation, the mixture was kneaded using a bead mill, to obtain a non-aqueous inkjet base cyan ink.

(25) <Manufacturing of Non-Aqueous Inkjet Base Yellow Ink>

(26) After dissolving 10 parts of a pigment dispersant (PB822) in 65 parts of diethylene glycol diethyl ether, and further mixing in 25 parts of a pigment (G01) under agitation, the mixture was kneaded using a bead mill, to obtain a non-aqueous inkjet base yellow ink.

(27) <Manufacturing of Non-Aqueous Inkjet Base Magenta Ink>

(28) After dissolving 10 parts of a pigment dispersant (SOLSPERSE 56000) in 65 parts of diethylene glycol diethyl ether, and further mixing in 25 parts of a pigment (RGT) under agitation, the mixture was kneaded using a bead mill, to obtain a non-aqueous inkjet base magenta ink.

(29) <Manufacturing of Non-Aqueous Inkjet Ink Composition>

(30) The materials were mixed under agitation according to the composition in Table 1 (the compounding ratio of each material is indicated in percent by mass), to obtain the non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2.

(31) (Printing Method and Printed Matters)

(32) The non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were each charged in a commercially available inkjet printer and printed solid on a polyvinyl chloride sheet in a high-speed printing mode, to obtain the printed matters in Examples 1 to 18 and Comparative Examples 1 and 2.

(33) <Evaluation>

(34) The printed matters using the non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were evaluated for the properties below. In the following evaluations, A and B indicate that the ink composition is fit for practical use, while C and D indicate problems using the ink composition as a product.

(35) (Viscosity)

(36) The non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were each measured for viscosity at 25 C. using a viscometer (RE100L manufactured by Toki Sangyo).

(37) (Fine Print)

(38) The non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were each used to print text in small font/type on a polyvinyl chloride sheet (product name: Kapjet Gloss Banner, manufactured by Filmolux) in a high-speed printing mode, and the results were visually evaluated for the level of clarity of fine print (characters bled or ran together).

(39) Evaluation Criteria

(40) A: No bleeding nor running together, and clear

(41) B: Bleeding and/or running together, but legible

(42) C: Bleeding and/or running together, and difficult to read

(43) (Solid Fill)

(44) The non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were each used to print solid areas on a polyvinyl chloride sheet (product name: Kapjet Gloss Banner, manufactured by Filmolux) in a high-speed printing mode, and the results were visually evaluated for filling of solid areas based on whether or not there were white spots in the images.

(45) Evaluation Criteria

(46) A: There are no white spots.

(47) B: There are some white spots.

(48) C: There are many white spots.

(49) (Anti-Mottling Property)

(50) The non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were each used to print solid areas in mixed colors (red, blue, green) on a polyvinyl chloride sheet (product name: Kapjet Gloss Banner, manufactured by Filmolux) in a standard mode, and the results were visually evaluated for mottled images.

(51) Evaluation Criteria

(52) A: There is no mottling.

(53) B: There is some mottling.

(54) C: There is a lot of mottling.

(55) (Discharge Stability)

(56) The non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were each printed on polyvinyl chloride sheets (product name: Kapjet Gloss Banner, manufactured by Filmolux), and the results were visually evaluated based on how many sheets were printed before unprinted areas appeared.

(57) Evaluation Criteria

(58) A: Unprinted areas appear on or after the 71st sheet, or unprinted areas do not appear until the 100th sheet.

(59) B: Unprinted areas appear between the 51st and 70th sheets.

(60) C: Unprinted areas appear between the 31st and 50th sheets.

(61) D: Unprinted areas appear on or before the 30th sheet.

(62) (Resolubility of Dried Coating Film)

(63) The non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were each filled in a silicon tube of 5 mm in inner diameter and 20 cm in length, and then let stand for five days at 25 C., to produce solidified ink in the tube. Next, each ink composition was filled in the tube again to evaluate, based on the following criteria, whether the solidified ink would dissolve again and the ink would flow out.

(64) Evaluation Criteria

(65) A: The ink flows out quickly.

(66) B: It takes time before the ink flows out.

(67) C: Some ink flows out.

(68) D: The tube remains blocked.

(69) (Rub Resistance)

(70) The non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were each transferred onto a polyvinyl chloride sheet (product name: Kapjet Gloss Banner, manufactured by Filmolux) using a Meyer bar (0.15 mm), and then the coating film was rubbed 100 times with a bleached cloth weighing 500 g using a Gakushin-type rubbing fastness tester (manufactured by Daiei Kagaku Seiki), after which the coating film was visually observed to evaluate the level of removal based on the following criteria.

(71) A: No coating film has been removed.

(72) B: There are surface scratches on the coating film.

(73) C: Some coating film has been removed.

(74) D: Notable portions of the coating film have been removed.

(75) (Solvent Resistance)

(76) The non-aqueous inkjet ink compositions in Examples 1 to 18 and Comparative Examples 1 and 2 were each transferred onto a polyvinyl chloride sheet (product name: Kapjet Gloss Banner, manufactured by Filmolux) using a Meyer bar (0.15 mm), and then the coating film was rubbed five times with a bleached cloth weighing 200 g and moistened with ethanol, using a Gakushin-type rubbing fastness tester (manufactured by Daiei Kagaku Seiki), after which the coating film was visually observed to evaluate the level of removal based on the following criteria.

(77) A: No coating film has been removed.

(78) B: There are surface scratches on the coating film.

(79) C: Some coating film has been removed.

(80) D: Notable portions of the coating film have been removed.

(81) TABLE-US-00001 TABLE 1 Examples 1 2 3 4 5 Black Black Black Black Black Pigment MA7 3.50% 3.50% 3.50% 3.50% 3.50% G01 RGT D7110F Dispersant RB822 SOLSPERSE 56000 SOLSPERSE 39000 1.40% 1.40% 1.40% 1.40% 1.40% Acrylic resin BR-87 6.00% 6.00% 5.00% 5.20% BR-83 4.80% BR-60 1.50% 1.20% 1.40% BR-106 Ketone resin SK 0.60% 1.00% 0.40% 1.00% 0.80% AP Solvent Diethylene glycol diethyl ether 58.50% 58.10% 58.20% 57.70% 58.10% Diethylene glycol ethyl methyl ether 20.00% 20.00% 20.00% 20.00% 20.00% Propylene carbonate 10.00% 10.00% 10.00% 10.00% 10.00% Diethylene glycol ethyl ether acetate Dipropylene glycol monomethyl ether Dipropylene glycol methyl ether acetate Total 100% 100% 100% 100% 100% Acrylic resin/ketone resin 10.0 6.0 16.3 6.4 7.8 Viscosity (mPa .Math. s) 5.0 5.0 4.9 4.9 5.0 Flash point 71 C. or 71 C. or 71 C. or 71 C. or 71 C. or above above above above above Fine print A A A A A Solid fill A A A A A Anti-mottling property A A A A A Discharge stability A A A A A Resolubility of dried coating film A A A A A Rub resistance A A A A A Solvent resistance A A A A A Examples 6 7 8 9 10 Black Black Black Black Black Pigment MA7 3.50% 3.50% 3.50% 3.50% 3.50% G01 RGT D7110F Dispersant RB822 SOLSPERSE 56000 SOLSPERSE 39000 1.40% 1.40% 1.40% 1.40% 1.40% Acrylic resin BR-87 4.80% 5.00% 6.00% 6.00% 6.00% BR-83 BR-60 BR-106 1.20% 2.00% Ketone resin SK 0.60% 1.50% 0.60% 0.60% 0.60% AP Solvent Diethylene glycol diethyl ether 58.50% 56.60% 48.50% 48.50% 48.50% Diethylene glycol ethyl methyl ether 20.00% 20.00% 20.00% 20.00% 20.00% Propylene carbonate 10.00% 10.00% 10.00% 10.00% 10.00% Diethylene glycol ethyl ether acetate 10.00% Dipropylene glycol monomethyl ether 10.00% Dipropylene glycol methyl ether acetate 10.00% Total 100% 100% 100% 100% 100% Acrylic resin/ketone resin 10.0 4.7 10.0 10.0 10.0 Viscosity (mPa .Math. s) 5.1 5.0 5.1 5.1 5.0 Flash point 71 C. or 71 C. or 71 C. or 71 C. or 71 C. or above above above above above Fine print A A A A A Solid fill A A A A A Anti-mottling property A A A A A Discharge stability A A A A A Resolubility of dried coating film A A A A A Rub resistance A A A A A Solvent resistance A A A A A Examples 11 12 13 14 15 Black Black Black Black Black Pigment MA7 3.50% 3.50% 3.50% 3.50% 3.50% G01 RGT D7110F Dispersant RB822 SOLSPERSE 56000 SOLSPERSE 39000 1.40% 1.40% 1.40% 1.40% 1.40% Acrylic resin BR-87 6.20% 6.20% 6.20% 5.80% 6.00% BR-83 BR-60 BR-106 Ketone resin SK 0.20% 3.00% AP 0.50% 1.00% 3.20% Solvent Diethylene glycol diethyl ether 58.40% 57.90% 58.70% 56.30% 55.90% Diethylene glycol ethyl methyl ether 20.00% 20.00% 20.00% 20.00% 20.00% Propylene carbonate 10.00% 10.00% 10.00% 10.00% 10.00% Diethylene glycol ethyl ether acetate Dipropylene glycol monomethyl ether Dipropylene glycol methyl ether acetate Total 100% 100% 100% 100% 100% Acrylic resin/ketone resin 12.4 6.2 31.0 1.9 1.9 Viscosity (mPa .Math. s) 4.9 5.0 4.9 5.0 5.1 Flash point 71 C. or 71 C. or 71 C. or 71 C. or 71 C. or above above above above above Fine print A A A A A Solid fill A A A A A Anti-mottling property A A A A A Discharge stability A A A B B Resolubility of dried coating film A A C A A Rub resistance A A A C D Solvent resistance A A A C D Comparative Examples Examples 16 17 18 1 2 Yellow Magenta Cyan Black Black Pigment MA7 3.50% 3.50% G01 3.00% RGT 3.00% D7110F 3.00% Dispersant RB822 1.20% SOLSPERSE 56000 1.20% 1.20% SOLSPERSE 39000 1.40% 1.40% Acrylic resin BR-87 5.80% 5.80% 6.20% 6.50% BR-83 BR-60 BR-106 Ketone resin SK 0.55% 0.55% 0.62% 3.00% AP Solvent Diethylene glycol diethyl ether 59.45% 59.45% 58.98% 58.60% 62.10% Diethylene glycol ethyl methyl ether 20.00% 20.00% 20.00% 20.00% 20.00% Propylene carbonate 10.00% 10.00% 10.00% 10.00% 10.00% Diethylene glycol ethyl ether acetate Dipropylene glycol monomethyl ether Dipropylene glycol methyl ether acetate Total 100% 100% 100% 100% 100% Acrylic resin/ketone resin 10.5 10.5 10.0 Viscosity (mPa .Math. s) 5.0 5.0 5.0 5.0 2.1 Flash point 71 C. or 71 C. or 71 C. or 71 C. or 71 C. or above above above above above Fine print A A A A B Solid fill A A A A A Anti-mottling property A A A A A Discharge stability A A A A C Resolubility of dried coating film A A A D A Rub resistance A A A A D Solvent resistance A A A A D

(82) According to the results of Examples 1 to 18 shown in Table 1, these non-aqueous inkjet ink compositions conforming to the composition of the present invention have viscosities suitable for inkjet applications. In addition, these inkjet compositions provide inks which have excellent fine print reproducibility, solid fill property, and anti-mottling property, and which, when the acrylic resin and the ketone resin are contained at an acrylic resin/ketone resin ratio of 3.0 to 20.0, also exhibit excellent discharge stability, resolubility of dried coating film, rub resistance, and solvent resistance; that is, inks achieving various properties in a balanced manner. On the other hand, Comparative Example 1 in which no ketone resin was used resulted in poor resolubility of dried coating film. Also, Comparative Example 2 in which no acrylic resin was used resulted in particularly poor discharge stability as well as poor fine print reproducibility, rub resistance, and solvent resistance.