ACTIVE ENERGY RAY-CURABLE INK COMPOSITION, METHOD FOR PRODUCING SAME, AND METHOD FOR PRODUCING PRINTED MATTER IN WHICH SAME IS USED

Abstract

To provide an active energy ray-curable ink composition that increase the content of raw materials derived from biomass and contains a material having superior pigment dispersibility, such as a rosin-modified phenol resin. An active energy ray-curable ink composition containing a compound having one or more ethylenically unsaturated bonds, a specific resin, and a specific liquid ingredient is provided, wherein the specific resin is at least one selected from the group consisting of rosin-modified phenol resins, rosin-modified maleic acid resins, rosin-modified alkyd resins, gilsonite resins, and asphalt resins, and the specific liquid ingredient is fat and oil that is derived from animals or vegetables or a modified product thereof having no ethylenically unsaturated bonds and a solubility parameter value (hereinafter referred to as sp value) of 9.0 (cal/cm.sup.3).sup.1/2 to less than 11.0 (cal/cm.sup.3).sup.1/2 as measured by turbidimetric titration.

Claims

1. An active energy ray-curable ink composition comprising: a compound having one or more ethylenically unsaturated bonds; a specific resin; and a specific liquid ingredient, wherein the specific resin is at least one selected from the group consisting of rosin-modified phenol resins, rosin-modified maleic acid resins, rosin-modified alkyd resins, gilsonite resins, and asphalt resins, and the specific liquid ingredient is fat and oil that is derived from animals or vegetables or a modified product thereof having no ethylenically unsaturated bonds and a solubility parameter (sp) value of 9.0 (cal/cm.sup.3).sup.1/2 to less than 11.0 (cal/cm.sup.3).sup.1/2 as measured by turbidimetric titration.

2. The active energy ray-curable ink composition according to claim 1, wherein the specific liquid ingredient is at least one selected from the group consisting of fat and oil that is derived from animals or vegetables or a modified product thereof having an sp value of 9.0 (cal/cm.sup.3).sup.1/2 to 10.0 (cal/cm.sup.3).sup.1/2, and cashew nut shell oil and a modified product thereof.

3. The active energy ray-curable ink composition according to claim 1, wherein the specific resin has an sp value of 8.0 (cal/cm.sup.3).sup.1/2 to 9.0 (cal/cm.sup.3).sup.1/2.

4. The active energy ray-curable ink composition according to claim 1, wherein the content of the specific liquid ingredient is 10 mass % to 50 mass % in the ink composition.

5. The active energy ray-curable ink composition according to claim 1, wherein the specific resin is a rosin-modified phenol resin.

6. The active energy ray-curable ink composition according to claim 1, wherein the specific liquid ingredient is at least one selected from the group consisting of castor oil, coconut oil, epoxidized vegetable oil, cashew nut shell oil, and a modified product of cashew nut shell oil.

7. A method for producing an active energy ray-curable ink composition containing a compound having one or more ethylenically unsaturated bonds, a specific resin, a specific liquid ingredient, and a photopolymerization initiator, the method comprising: a step of dissolving the specific resin in the heated specific liquid ingredient to prepare a varnish, wherein the specific resin is at least one selected from the group consisting of rosin-modified phenol resins, rosin-modified maleic acid resins, rosin-modified alkyd resins, gilsonite resins, and asphalt resins, and the specific liquid ingredient is fat and oil that is derived from animals or vegetables or a modified product thereof having no ethylenically unsaturated bonds and a solubility parameter (sp) value of 9.0 (cal/cm.sup.3).sup.1/2 to less than 11.0 (cal/cm.sup.3).sup.1/2 as measured by turbidimetric titration.

8. A method for producing printed matter, comprising a step of printing with the active energy ray-curable ink composition according to claim 1.

Description

EXAMPLES

[0104] The present invention will be described in further detail by way of the following examples, although the present invention should not be limited to these examples. In the following description, “%” indicates “mass %” and “parts” indicates “parts by mass” unless otherwise specified. The unit of the sp value is (cal/cm.sup.3).sup.1/2

[0105] [Preparation of Varnish 1]

[0106] Rosin-modified phenol resin (40 parts by mass, sp value: 8.83) was dissolved in epoxidized soybean oil (60 parts by mass) at 200° C. for 60 minutes to prepare Varnish 1.

[0107] [Preparation of Varnish 2]

[0108] Varnish 2 was prepared as in Varnish 1 except that castor oil was used in place of epoxidized soybean oil.

[0109] [Preparation of Varnish 3]

[0110] Varnish 3 was prepared as in Varnish 1 except that trimethylolpropane triacrylate (TMPTA) was used in place of the epoxidized soybean oil. However, the resin was not dissolved in Varnish 3.

[0111] [Preparation of Varnish 4]

[0112] Varnish 4 was prepared as in Varnish 1 except that soybean oil was used in place of epoxidized soybean oil.

[0113] [Preparation of Varnish 5]

[0114] Polydiallyl phthalate (40 parts by mass, A-DAP, available from Osaka Soda Co., Ltd.) was dissolved in TMPTA (60 parts by mass) at 100° C. for 60 minutes to prepare Varnish 5. Varnish 5 is equivalent to varnish used in a conventional active energy ray-curable ink composition that contains no specific resin.

[0115] [Preparation of Ink Composition]

[0116] Carbon black (MA-70, available from Mitsubishi Chemical Corporation), Varnishes described above, trimethylolpropane triacrylate (TMPTA), ditrimethylolpropane tetraacrylate (DI-TMPTA), Irgacures 907 and 184 (trade name, available from BASF SE, photopolymerization initiators), and polyethylene wax are mixed according to formulations shown in Table 1 and then kneaded with a three-roll mill to prepare ink compositions of Examples 1 and 2, Comparative example 1, and Reference example 1. Since the resin was not dissolved in Varnish 3 where the inventive specific liquid ingredient was not used as described above, Varnish 3 was not employed in the preparation of the ink composition.

[0117] [Evaluation of Gloss]

[0118] For each ink composition of Examples, Comparative example, and Reference example, 0.1 cc of ink composition was spread onto coated paper (Aurora Coat, available from Nippon Paper Industries co., Ltd.) with an RI drawdown machine (Two-split roll, available from Akira Co., Ltd.) and then cured by irradiation with ultraviolet rays in an irradiation dose of 40 mJ/cm.sup.2. The density of ink composition was adjusted such that the density immediately after curing exhibited 1.50, the density being measured with a Spectroeye densitometer (available from GretagMacbeth GmbH). The 600 reflected gloss of each spread surface was determined with a Murakami digital gloss meter (available from Murakami Color Research Laboratory). The results are shown in the column “Gloss” of Table 1. It is noted that the ink composition causing some precipitates due to poor compatibility was not evaluated and shown as “unevaluable” in each column.

[0119] [Evaluation of Curability]

[0120] For each ink composition of Examples, Comparative example, and Reference example, curability was evaluated. 0.1 cc of ink composition was spread onto coated paper (Aurora Coat, available from Nippon Paper Industries co., Ltd.) with an RI drawdown machine (Two-split roll, available from Akira Co., Ltd.) and then immediately cured by irradiation with ultraviolet rays (metal halide lamp, an irradiation dose of 36 mJ/cm.sup.2) to form a cured film of the spread ink composition. After the resultant cured film was left at room temperature for one minute, the surface of the film (i.e., the printed surface) was rubbed with a Gakushin type Color fastness rubbing tester (load: 1 kg, cover paper: woodfree paper) ten times. The state on the printed surface after rubbing was visually observed and was ranked into the following four-stage criterion. The results are shown in the column “Curability” of Table 1.

[0121] .circle-solid.: no scratches on the printed surface, indicating very good film

[0122] ∘: Slight scratches on the printed surface, indicating no practical problem

[0123] Δ: Conspicuous scratches on the printed surface

[0124] X: Separation of the film on the printed surface

TABLE-US-00001 TABLE 1 Comparative Reference Example 1 Example 2 Example 1 Example 1 Varnish 1 41 Varnish 2 41 Varnish 4 41 Varnish 5 41 Carbon black 20 20 20 20 TMPTA 6 6 6 6 DI-TMPTA 21 21 21 21 Irgacure 907 8 8 8 8 Irgacure184 3 3 3 3 Polyethylene wax 1 1 1 1 Total 100 100 100 100 Slope 8.9 9.2 unevaluable 9.0 Gloss 40 42 unevaluable 35 Curability .circle-solid. .circle-solid. unevaluable .circle-solid.

[0125] Table 1 illustrates that the inventive ink composition exhibited compatibility similar to and had better gloss than a conventional active energy ray-curable ink composition (Reference example 1) although rosin-modified phenol resin was used. These results evidentially demonstrate that the specific resin, which has been difficult to be employed in the active energy ray-curable ink composition, can be used in combination with a specific liquid ingredient.