Nonaqueous ink-jet magenta ink composition

Abstract

A non-aqueous magenta ink composition for ink jet printing comprising a pigment, a pigment dispersant, a binder resin and an organic solvent, wherein the pigment comprises C.I. Pigment Red 254 and a red pigment having a quinacridone skeleton, and wherein a total amount of the C.I. Pigment Red 254 and the red pigment having a quinacridone skeleton is not less than 50% by mass in the pigment.

Claims

1. A non-aqueous magenta ink composition for ink jet printing comprising a pigment, a pigment dispersant, a binder resin and an organic solvent, wherein the pigment comprises C.I. Pigment Red 254 and a red pigment having a quinacridone skeleton, wherein a total amount of the C.I. Pigment Red 254 and the red pigment having a quinacridone skeleton is not less than 50% by mass in the pigment, wherein the compounding ratio of the C.I. Pigment Red 254 to the red pigment having a quinacridone skeleton is 4:6 to 6:4, and wherein the organic solvent comprises alkylene glycol dialkyl ether.

2. The non-aqueous magenta ink composition for ink jet printing of claim 1, wherein the pigment having a quinacridone skeleton is at least one selected from C.I. Pigment Violet 19, C.I. Pigment Red 122 and C.I. Pigment Red 202.

3. The non-aqueous magenta ink composition for ink jet printing of claim 1, wherein the pigment having a quinacridone skeleton is C.I. Pigment Red 122.

4. The non-aqueous magenta ink composition for ink jet printing of claim 1, wherein the binder resin comprises at least either of a vinyl polymer and an acrylic resin, and the vinyl polymer comprises at least one selected from the group consisting of a vinyl chloride polymer, a vinyl chloride-vinyl acetate copolymer and an ethylene-vinyl acetate copolymer.

5. The non-aqueous magenta ink composition for ink jet printing of claim 1, comprising the organic solvent comprising at least one selected from the group consisting of a cyclic ester compound, (poly)propylene glycol monoalkyl ether and (poly)propylene glycol monoalkyl ether monoalkyl ester in a total amount of 1 to 30% by mass in the non-aqueous magenta ink composition.

Description

EXAMPLE

(1) The present invention is explained below specifically by means of Examples. The present invention is not limited to these Examples. In addition, % means % by mass and part means part by mass unless restricted otherwise.

(2) Starting materials used and a preparation method are described below.

(3) <Pigment Dispersant>

(4) SOLSPERSE 39000 (available from The Lubrizol Corporation)

(5) <Binder Resin>

(6) Evaflex E15/45 (vinyl chloride-vinyl acetate copolymer available from Wacker Chemie AG)

(7) SOLBIN C (vinyl chloride-vinyl acetate copolymer available from Nissin Chemical Co., Ltd.)

(8) Dianal BR-87 (acrylic resin available from Mitsubishi Rayon Co., Ltd.)

Examples 1 to 9 and Comparative Examples 1 to 4

(9) Each of starting materials was stirred and mixed in a compounding formulation shown in Table 1, and thus, ink compositions were prepared. A viscosity, weather resistance and color gamut of the obtained ink compositions were evaluated by the following evaluation methods. The results are shown in Table 1.

(10) TABLE-US-00001 TABLE 1 Example 1 2 3 4 5 6 7 8 9 Pigment C.I. Pigment Red 254 0.8 1.6 2.4 3.2 1.6 1.6 1.6 1.6 1.6 C.I. Pigment Red 122 3.2 2.4 1.6 0.8 1.6 2.4 2.4 C.I. Pigment Violet 19 2.4 C.I. Pigment Red 202 2.4 C.I. Pigment Red 146 0.8 Organic solvent Diethylene glycol diethyl ether 51 51 51 51 51 51 61 51 51 Propylene carbonate 20 20 20 20 20 20 20 20 20 Tetraethylene glycol dimethyl ether 20 20 20 20 20 20 10 20 20 Pigment dispersant SS39000 2 2 2 2 2 2 2 2 2 Binder resin E15/45 3 3 3 3 3 3 3 SOLBIN C 3 BR87 3 Total 100 100 100 100 100 100 100 100 100 Evaluation Viscosity 5.1 4.7 4.5 4.3 4.3 4.9 4.6 4.6 4.8 Weather resistance B A A A B A A A A Color gamut A A A B A A A B A Ejection stability A A A A A A A A A Solid embedment A A A A A A A A A Comparative Example 1 2 3 4 Pigment C.I. Pigment Red 254 4 0.5 C.I. Pigment Red 122 4 0.5 C.I. Pigment Violet 19 C.I. Pigment Red 202 C.I. Pigment Red 146 4 3 Organic solvent Diethylene glycol diethyl ether 51 51 51 51 Propylene carbonate 20 20 20 20 Tetraethylene glycol dimethyl ether 20 20 20 20 Pigment dispersant SS39000 2 2 2 2 Binder resin E15/45 3 3 3 3 SOLBIN C BR87 Total 100 100 100 100 Evaluation Viscosity 3.8 3.8 3.8 4.4 Weather resistance A B C C Color gamut C C A A Ejection stability A A A A Solid embedment A A A A
(Viscosity)

(11) Viscosities of the ink compositions at 25 C. were measured by using a viscometer (RE100L type viscometer available from TOKI SANGYO CO., LTD.).

(12) (Weather Resistance)

(13) Each of ink compositions prepared in Examples 1 to 9 and Comparative Examples 1 to 4 was subjected to color exhibition on a vinyl chloride substrate using Meyaba having a diameter of 0.15 mm. Thereafter, weathering test was conducted for 1,000 hours using a weatherometer (Q-SUN manufactured by Q-Lab Co., Ltd.) and a color difference E was measured using a spectrophotometer (Spectro Eye manufactured by X-Rite Co., Ltd.). With respect to the obtained color difference E, light fastness was evaluated in accordance with the following evaluation criteria. The smaller the color difference E is, the better the weather resistance is.

(14) (Evaluation Criteria)

(15) A: E was less than 10.

(16) B: E was 10 or more and less than 20.

(17) C: E was 20 or more.

(18) (Color Gamut)

(19) Each of ink compositions prepared in Examples 1 to 9 and Comparative Examples 1 to 4 was subjected to color exhibition on a vinyl chloride substrate using Meyaba having a diameter of 0.15 mm. Thereafter, a b* value in L*a*b* color system was calculated using a spectrophotometer (Spectro Eye manufactured by X-Rite Co., Ltd.). With respect to the obtained b* value, light fastness was evaluated in accordance with the following evaluation criteria. It is noted that when the b* value is about more than 5 and about less than 25, it can be evaluated such that a magenta color having a proper yellowness is exhibited.

(20) (Evaluation Criteria)

(21) A: b* was more than 5 and less than 25.

(22) B: b* was more than 0 and 5 or less, or 25 or more and less than 30.

(23) C: b* was 10 or less, or 30 or more.

(24) (Ejection Stability)

(25) Each of ink compositions prepared in Examples 1 to 9 and Comparative Examples 1 to 4 was printed on a polyvinyl chloride sheet (trade name Kapujet gurosubana manufactured by FILMOLUX CO., LTD.) and ejection stability was evaluated by the number of sheets when an unprinted part arises.

(26) (Evaluation Criteria)

(27) A: An unprinted part did not arise after 71.sup.st sheet, or an unprinted part did not arise up to 100.sup.th sheet.

(28) B: An unprinted part arose between the 51.sup.st sheet and the 71.sup.th sheet.

(29) C: An unprinted part arose before 50.sup.th sheet.

(30) (Solid Embedment)

(31) Each of ink compositions prepared in Examples 1 to 9 and Comparative Examples 1 to 4 was subjected to solid printing on a polyvinyl chloride sheet (trade name Kapujet gurosubana manufactured by FILMOLUX CO., LTD.) by a high speed printing mode, and with respect to filling of a solid portion, whether or not there is white spot printing in a printed image, namely whether or not solid embedment is satisfactory was evaluated visually.

(32) (Evaluation Criteria)

(33) A: There was no white spot printing.

(34) B: There was somewhat white spot printing.

(35) C: There was a lot of white spot printing.

(36) As shown in Table 1, in any of the ink compositions of Examples 1 to 9 comprising C.I. Pigment Red 254 and a red pigment having a quinacridone skeleton in an amount of 50% by mass or more in the pigment, weather resistance was excellent and a color having strong yellowness could be exhibited. Further, each of the ink compositions prepared in Examples 1 to 9 has good ejection stability and solid embedment (white spot printing). On the other hand, in the ink compositions of Comparative Examples 1 to 4, where either of the above-mentioned pigments is not contained or a total amount of the pigments is smaller than a predetermined amount, weather resistance was inferior or a magenta color having a proper yellowness could not be exhibited.