Varnish, offset printing ink composition, and production method for offset-printed object

Abstract

A varnish for use in an offset printing ink composition, said varnish containing a hydrocarbon-based solvent that is derived from biomass and has a boiling point of 200°C or higher.

Description

Varnish, offset printing ink composition, and method for producing offset printed matter

[0001] The present invention relates to a varnish, an offset printing ink composition, and a method for producing an offset printed matter.

[0002] In the field of offset printing, efforts to reduce the burden on the environment have led to the development and commercialization of inks that use aroma-free petroleum-based solvents with an aromatic content of less than 1% by weight, as well as non-VOC inks that contain no volatile petroleum-based solvents. In recent years, offset printing inks have adopted the Biomass Mark (Japan Organics Recycling Association), which indicates environmentally friendly products made from biological resources. From the perspective of global warming, there is an ever-increasing need for inks that contain higher amounts of biomass-derived, high-boiling-point solvents, such as those derived from vegetable oils, rather than high-boiling-point petroleum-based inks. This is consistent with the international goal of creating a better, more sustainable world.

[0003] For example, Patent Document 1 proposes a non-VOC offset printing ink composition using a biomass-derived fatty acid ester. Also, Patent Document 2 proposes a hydrocarbon-based fluid derived from a product derived from biomass conversion, containing more than 50% by weight of isoparaffins and 40% by weight or less of naphthenes, and claims that the hydrocarbon-based fluid can be used as a component of a "cold-set" newsprint offset ink composition.

[0004] JP 2016-204557 A JP 2012-520370 A

[0005] However, Patent Document 1 only states that the fatty acid ester is derived from biomass, and petroleum-based high-boiling point solvents such as AF Solvent No. 7 are used to the same extent as in conventional offset printing inks. Patent Document 2 only mentions "hydrocarbon-based fluids derived from products derived from biomass conversion," and does not explain or suggest anything about "biomass conversion" regarding hydrocarbon-based fluids (which are thought to be synonymous with "petroleum-based high-boiling point solvents").

[0006] Offset printing inks typically use petroleum-based high-boiling-point solvents in amounts of 20 to 45% by mass of the total ink. Because offset printing is used for mass-printed materials such as general books and newspapers, if these petroleum-based high-boiling-point solvents could be made from biomass, it would lead to a significant reduction in the burden on the environment.

[0007] The present invention aims to provide a varnish, an offset printing ink composition, and a method for producing offset printed matter that use a biomass-derived solvent and that exhibit performance equal to or better than that of a petroleum-based solvent. Another object of the present invention is to provide an offset printing ink composition and a method for producing printed matter using the same that reduce the environmental impact by using a biomass-derived solvent instead of a petroleum-based solvent.

[0008] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by using a hydrocarbon solvent derived from biomass as a high-boiling point solvent, and have thus completed the present invention.

[0009] That is, according to the present invention, there are provided the following varnish, offset printing ink composition, and method for producing offset printed matter: (1) A varnish used in an offset printing ink composition, the varnish containing a biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher, (2) The varnish according to (1), in which the biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher contains an α-olefin solvent, (3) The varnish according to (2), in which the α-olefin solvent contains 1-hexadecene and 1-octadecene, (4) The varnish according to any one of (1) to (3), in which the content of the biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher is 1 part by mass to 90 parts by mass per 100 parts by mass of the varnish, (5) An offset printing ink composition containing the varnish according to any one of (1) to (4), (6) An offset printing ink composition containing a biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher, (7) The offset printing ink composition according to (5) or (6), wherein the content of the biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher is 1 part by mass or more and 90 parts by mass or less per 100 parts by mass of the offset printing ink composition; (8) The offset printing ink composition according to any one of (5) to (7), wherein the time required for the tack value to reach a peak value as evaluated by the following <Method 1> is 26 minutes or more; <Method 1> The offset printing ink composition is rotated on a digital incomer under the conditions of an ink amount of 1.31 cc, room temperature of 25°C, a roller temperature of 35°C, and a rotation speed of 1200 rpm, and the time required for the tack value to reach a peak value is measured. (9) The offset printing ink composition according to any one of (5) to (8), having a density of 2.00 or more as evaluated by the following <Method 2>. <Method 2> The offset printing ink composition is applied to coated paper using an RI tester, and then immediately dried in an oven at 120°C for 15 seconds, and the color density of the applied surface is measured using a Gretag Macbeth SpectroEye.(10) A method for producing an offset printed matter, comprising the steps of preparing a substrate and offset printing the offset printing ink composition according to any one of (5) to (9) onto the substrate; and (11) A method for producing an offset printed matter according to (10), in which the substrate is paper.

[0010] According to the present invention, it is possible to provide a varnish, an offset printing ink composition, and a method for producing an offset printed product that use a biomass-derived solvent and yet exhibit performance equal to or better than that when a petroleum-based solvent is used. Furthermore, according to the present invention, it is possible to provide a varnish, an offset printing ink composition, and a method for producing an offset printed product that reduce the environmental load by using a biomass-derived solvent instead of a petroleum-based solvent.

[0011] Hereinafter, an embodiment of the present invention will be described in detail. Note that this embodiment is merely one embodiment of the present invention, and the present invention is not limited to this embodiment. Various modifications are possible within the scope of the present invention.

[0012] <Varnish> The varnish according to this embodiment is a varnish used in an offset printing ink composition, and contains a biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher.

[0013] An example of the biomass-derived hydrocarbon solvent according to this embodiment is NovaSolv 160, an α-olefin produced from biomass by Novvi LLC in the U.S. NovaSolv 160 is a mixture containing 1-hexadecene (content ratio: 95 to 99% by mass) and 1-octadecene (content ratio: 1 to 5% by mass).

[0014] In the varnish for offset printing ink according to this embodiment, a part or all of the conventional petroleum-based solvent can be replaced with a hydrocarbon-based solvent derived from biomass.

[0015] The biomass-derived hydrocarbon solvent according to this embodiment is produced from renewable biomass (plants). That is, it is produced through processes such as a plant cultivation process, a transportation process, and a process for producing α-olefins from plants. In these processes, CO ２ According to the environmental impact assessment of ILCD 2011 Midpoint [v1.0.10, August 2016], the α-olefin solvent according to this embodiment has a total CO 2 emission of 25,000 tons per year in a commercial continuous production. ２ It has been confirmed that emissions will be negative.

[0016] According to the Chemical Industry Statistics for 2021, the production volume of offset printing ink in Japan, including that for newspapers, is approximately 90,000 tons, and it is believed that most of this is made using petroleum-based solvents. Assuming that 90% of offset printing inks use petroleum-based solvents and that the ink contains 30 to 40% by mass of petroleum-based solvents, it is possible to replace 24,000 to 32,000 tons of petroleum-based solvents used in offset printing inks with the biomass-derived hydrocarbon solvents of this embodiment, resulting in a sustainable and CO2-free printing process. ２ This will enable emissions reductions.

[0017] The boiling point of the biomass-derived hydrocarbon solvent according to this embodiment is 200°C or higher, preferably 220°C or higher, more preferably 240°C or higher, even more preferably 250°C or higher, and even more preferably 260°C or higher. From the viewpoint of suppressing the emission and dispersion of VOC components into the atmosphere, it is preferably 265°C or higher, even more preferably 270°C or higher, even more preferably 275°C or higher, and even more preferably 280°C or higher. Furthermore, the boiling point of the biomass-derived hydrocarbon solvent according to this embodiment is, for example, 350°C or lower. Here, VOC stands for Volatile Organic Compounds, and refers to volatile organic compounds. The WHO defines VOC as a general term for organic compounds present in the atmosphere in gaseous form with a boiling point of 50°C to 260°C. The biomass-derived hydrocarbon solvent according to this embodiment preferably does not contain VOCs. As a result, when used as an ink for offset rotary printing and passed through a dryer during printing, no VOC components are emitted or dispersed into the atmosphere.

[0018] The biomass-derived hydrocarbon solvent according to this embodiment contains, for example, one or more solvents selected from the group consisting of chain saturated hydrocarbon solvents, chain unsaturated hydrocarbon solvents, cyclic saturated hydrocarbon solvents, and cyclic unsaturated hydrocarbon solvents, and from the viewpoint of further improving printing performance, preferably contains a chain unsaturated hydrocarbon solvent, more preferably contains an α-olefin solvent.

[0019] The α-olefin solvent according to the present embodiment includes, for example, one or more selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-icosene. From the viewpoint of further improving printing performance, the α-olefin solvent preferably includes one or more selected from the group consisting of 1-hexadecene and 1-octadecene, and more preferably includes 1-hexadecene and 1-octadecene.

[0020] When the α-olefin solvent according to the present embodiment contains 1-hexadecene and 1-octadecene, the content of 1-hexadecene relative to the total α-olefin solvent is, from the viewpoint of further improving printing performance, preferably 75% by mass or more, more preferably 85% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and is, for example, 99% by mass or less.

[0021] In the varnish according to the present embodiment, the content of the biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher per 100 parts by mass of the varnish is, from the viewpoint of further improving printing performance and further reducing the environmental load, preferably 1 part by mass or more, more preferably 3 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, even more preferably 30 parts by mass or more, and even more preferably 35 parts by mass or more; and, from the viewpoint of further improving printing performance, is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, even more preferably 50 parts by mass or less, and even more preferably 45 parts by mass or less.

[0022] The varnish according to the present embodiment contains, for example, one or more additives selected from the group consisting of solvents other than hydrocarbon solvents derived from biomass and having a boiling point of 200°C or higher, such as petroleum-based solvents, rosin-modified phenolic resins, vegetable oils (e.g., refined soybean oil), chelating agents (e.g., aluminum chelating agents), stabilizers, higher alcohols, antioxidants, petroleum resins, and fatty acid esters.

[0023] When the varnish according to this embodiment contains a petroleum-based solvent, the content of the petroleum-based solvent per 100 parts by mass of the varnish is preferably at least 1 part by mass, more preferably at least 2 parts by mass, even more preferably at least 5 parts by mass, even more preferably at least 10 parts by mass, and is preferably at most 50 parts by mass, more preferably at most 40 parts by mass, even more preferably at most 30 parts by mass, even more preferably at most 20 parts by mass. An example of a commercially available petroleum-based solvent is "AF Solvent No. 7" manufactured by ENEOS Corporation, which is a high-boiling point petroleum-based solvent.

[0024] When the varnish according to the present embodiment contains a rosin-modified phenolic resin, the content of the rosin-modified phenolic resin per 100 parts by mass of the varnish is preferably at least 1 part by mass, more preferably at least 5 parts by mass, even more preferably at least 10 parts by mass, even more preferably at least 20 parts by mass, even more preferably at least 30 parts by mass, even more preferably at least 40 parts by mass, and is preferably at most 90 parts by mass, more preferably at most 80 parts by mass, even more preferably at most 70 parts by mass, even more preferably at most 60 parts by mass, even more preferably at most 50 parts by mass. An example of a commercially available rosin-modified phenolic resin is "Tamanol 412" manufactured by Arakawa Chemical Industries, Ltd.

[0025] When the varnish according to this embodiment contains a vegetable oil such as refined soybean oil, the content of the vegetable oil per 100 parts by mass of the varnish is preferably at least 1 part by mass, more preferably at least 2 parts by mass, even more preferably at least 5 parts by mass, even more preferably at least 10 parts by mass, even more preferably at least 15 parts by mass, and preferably at most 50 parts by mass, more preferably at most 40 parts by mass, even more preferably at most 30 parts by mass, even more preferably at most 20 parts by mass. An example of a commercially available vegetable oil is "Refined Soybean Oil" manufactured by The Nisshin Oillio Group, Ltd.

[0026] The method for producing the varnish according to this embodiment is not particularly limited, but it can be produced by heating and mixing the raw materials while dissolving them.

[0027] <Offset Printing Ink Composition> The offset printing ink composition according to this embodiment contains the varnish described above.

[0028] The offset printing ink composition according to this embodiment contains a biomass-derived hydrocarbon solvent having a boiling point of 200° C. or higher.

[0029]

[0043] In the offset printing ink composition according to this embodiment, the content of the biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher, relative to 100 parts by mass of the offset printing ink composition, is preferably 1 part by mass or more, more preferably 3 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more, from the viewpoint of further improving printing performance, further reducing the environmental load, and improving coloring density; and is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, even more preferably 50 parts by mass or less, even more preferably 45 parts by mass or less, even more preferably 40 parts by mass or less, and even more preferably 35 parts by mass or less, from the viewpoint of further improving printing performance.

[0030] In the offset printing ink composition according to this embodiment, from the viewpoint of improving on-press stability, the content of the biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher per 100 parts by mass of the offset printing ink composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more. Note that the state in which on-press stability is improved refers to, for example, a state in which the time required for the tack value to reach its peak value, as evaluated by <Method 1> below, is long.

[0031] In the offset printing ink composition according to this embodiment, the time required for the tack value, evaluated by the following <Method 1>, to reach its peak value is preferably 26 minutes or more, more preferably 29 minutes or more, even more preferably 35 minutes or more, even more preferably 40 minutes or more, even more preferably 45 minutes or more, and even more preferably 50 minutes or more.

[0032] <Method 1> The offset printing ink composition according to this embodiment is applied to a digital incometer under the following conditions: an ink amount of 1.31 cc, a room temperature of 25°C, a roller temperature of 35°C, and a rotation speed of 1200 rpm, and the time required for the tack value to reach its peak is measured.

[0033] To add a little more about the evaluation using the above-mentioned <Method 1>, when the digital incometer is rotated under the conditions of the above-mentioned <Method 1>, the tack value rises as soon as the rotation starts, reaches a peak value at a certain point, and then drops. The reason why the tack value drops after reaching a peak value is because ink peeling occurs on the incometer roller at the time of the peak value. Therefore, the time required for the tack value to reach a peak value can be considered to be the time required for ink peeling to occur. In other words, the longer the time required for the tack value to reach a peak value, the longer the time required for ink peeling to occur, which means that the on-press stability can be considered to be high.

[0034] In the offset printing ink composition according to this embodiment, the density evaluated by the following <Method 2> is preferably 2.00 or more, more preferably 2.05 or more, and even more preferably 2.10 or more.

[0035] <Method 2> The offset printing ink composition according to this embodiment is applied to coated paper using an RI tester, and then immediately dried in an oven at 120°C for 15 seconds, and the color density of the applied surface is measured using a Gretag Macbeth SpectroEye.

[0036] The offset printing ink composition according to the present embodiment may further contain one or more additives selected from the group consisting of, for example, petroleum-based solvents and other solvents other than hydrocarbon-based solvents derived from biomass and having a boiling point of 200°C or higher, rosin-modified phenolic resins, vegetable oils (e.g., refined soybean oil), colorants such as coloring pigments, fillers, chelating agents (e.g., aluminum chelating agents), stabilizers, higher alcohols, waxes, dispersants, and antioxidants.

[0037]

[0043] When the offset printing ink composition according to this embodiment contains a petroleum-based solvent, the content of the petroleum-based solvent per 100 parts by mass of the offset printing ink composition is preferably at least 1 part by mass, more preferably at least 2 parts by mass, even more preferably at least 5 parts by mass, even more preferably at least 10 parts by mass, even more preferably at least 20 parts by mass, even more preferably at least 30 parts by mass, and preferably at most 70 parts by mass, more preferably at most 60 parts by mass, even more preferably at most 50 parts by mass, even more preferably at most 45 parts by mass, even more preferably at most 40 parts by mass. An example of a commercially available petroleum-based solvent is "AF Solvent No. 7" manufactured by ENEOS Corporation, which is a high-boiling point petroleum-based solvent.

[0038] When the offset printing ink composition according to this embodiment contains a colorant, the content of the colorant per 100 parts by mass of the offset printing ink composition is preferably at least 1 part by mass, more preferably at least 2 parts by mass, even more preferably at least 5 parts by mass, even more preferably at least 10 parts by mass, even more preferably at least 15 parts by mass, and preferably at most 50 parts by mass, more preferably at most 40 parts by mass, even more preferably at most 30 parts by mass, even more preferably at most 20 parts by mass. An example of a commercially available colorant is "Fastgen Blue FA5380" manufactured by DIC Corporation.

[0039] The method for producing the offset printing ink composition according to this embodiment is not particularly limited, but the composition can be produced by dispersing a colorant such as a color pigment in a varnish using a triple roll mill, a bead mill, or the like to prepare an ink base, and then mixing other raw materials into the prepared ink base.

[0040] <Method for Producing Offset Printed Material> The method for producing an offset printed material according to this embodiment includes the steps of preparing a substrate and offset printing the offset printing ink composition onto the substrate.

[0041] The material of the substrate is not particularly limited as long as it is suitable for offset printing, but paper is preferred. Examples of paper used as the substrate include sawdust (uncoated paper), lightly coated paper, coated paper (gloss / matt), and art paper.

[0042] The method for producing an offset printed product according to this embodiment preferably further includes a step of drying the ink used for offset printing.

[0043] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0044] [Preparation of Varnish] First, the following raw materials were prepared: - Biomass-derived α-olefin solvent (α-olefin-based solvent containing 95 to 99 mass% of 1-hexadecene and 1 to 5 mass% of 1-octadecene, "NovaSolv 160" manufactured by Novvi LLC, boiling point 265 to 309°C) - Petroleum-based high-boiling point solvent ("AF Solvent No. 7" manufactured by ENEOS Corporation, boiling point 259 to 282°C) - Rosin-modified phenolic resin ("Tamanol 412" manufactured by Arakawa Chemical Industries, Ltd.) - Refined soybean oil ("Refined soybean oil" manufactured by Nisshin Oillio Group, Inc.) - Chelating agent ("ALCH" manufactured by Kawaken Fine Chemicals Co., Ltd., chemical name: aluminum ethyl acetoacetate diisopropylate) An antioxidant (BHT Swanox manufactured by Seiko Chemical Co., Ltd., compound name: 2,6-Di-tert-butyl-4-methylphenol) was then charged into a reaction vessel in the proportions shown in Table 1, and the mixture was heated to 185°C while blowing in nitrogen gas, followed by mixing and stirring for 60 minutes to obtain varnishes V1 and Varnish V2.

[0045]

[0046] [Production of Offset Printing Ink Composition] First, the following raw materials were prepared. Varnish V1 Varnish V2 Colorant (Firstgen Blue FA5380 manufactured by DIC Corporation) Biomass-derived α-olefin solvent (α-olefin-based solvent containing 95 to 99% by mass of 1-hexadecene and 1 to 5% by mass of 1-octadecene, NovaSolv 160 manufactured by Novvi LLC, boiling point 265 to 309°C) Petroleum-based high-boiling point solvent (AF Solvent No. 7 manufactured by ENEOS Corporation, boiling point 259 to 282°C) Higher alcohol (Neodol 45 manufactured by Shell Chemicals) Wax (PL-2020 manufactured by Morimura Chemical Co., Ltd.) Next, the varnish and colorant in the formulations shown in Table 2 were milled in a three-roll mill to obtain an ink base. Next, the resulting ink base was mixed with the remaining ingredients in the formulation shown in Table 2 to obtain an offset printing ink composition.

[0047] The ink composition of Comparative Example 1 is equivalent to a conventionally widely used offset printing ink composition.

[0048] The offset printing ink compositions of Examples 1 and 2 and Comparative Example 1 were evaluated as follows. The results are shown in Table 2.

[0049] [Flowability] For each of the offset printing ink compositions of Examples 1 and 2 and Comparative Example 1, the 1-minute and 2-minute values ​​of the ink spread diameter (mm) were measured using a spread meter (manufactured by Toyo Seiki Seisaku-sho, Ltd.). The results were evaluated on a three-level scale of A to C. Specifically, Comparative Example 1 was rated B, with A being a diameter larger than Comparative Example 1, B being the same as Comparative Example 1, and C being a diameter smaller than Comparative Example 1.

[0050] [Tack] For each of the offset printing ink compositions of Examples 1 and 2 and Comparative Example 1, a digital incometer (manufactured by Toyo Seiki Seisaku-sho, Ltd.) was used to measure the numerical value (tack value) after 1 minute under the conditions of an ink amount of 1.31 cc, a room temperature of 25°C, a roller temperature of 30°C, and a rotation speed of 400 rpm. The lower the tack value, the more resistant to paper peeling and the better the result. The results were evaluated on a three-level scale of A to C. Specifically, Comparative Example 1 was rated B, with A being a tack value lower than Comparative Example 1, B being equivalent to Comparative Example 1, and C being a tack value higher than Comparative Example 1.

[0051] [Color Density] Each of the offset printing ink compositions of Examples 1 and 2 and Comparative Example 1 was applied to coated paper using an RI tester (manufactured by Akebono Seisakusho Co., Ltd.) and then immediately dried in an oven at 120°C for 15 seconds. The color density of the applied surface of this sample piece was measured using a GretagMacbeth Spectroeye (manufactured by GretagMacbeth). The color density for Example 1 was 2.11, for Example 2 was 2.08, and for Comparative Example 1 was 1.99. The results were evaluated on a three-level scale of A to C. Specifically, Comparative Example 1 was assigned a grade of B, with A being a grade for a color density higher than Comparative Example 1, B being equivalent to Comparative Example 1, and C being a grade for a color density lower than Comparative Example 1.

[0052] [Rubbing Resistance] Each of the offset printing ink compositions of Examples 1 and 2 and Comparative Example 1 was applied to coated paper using an RI tester (manufactured by Akebono Seisakusho Co., Ltd.) and immediately dried for 15 seconds in an oven at 120°C. The sample piece was allowed to cool for 1 minute, and the ink surface was rubbed with white paper using a Gakushin-type dye fastness tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), and the degree of color fading was evaluated visually. The less color fading, the better the rub resistance. The results were evaluated on a three-level scale, from A to C. Specifically, Comparative Example 1 was assigned a grade of B, with A indicating a lower degree of color fading than Comparative Example 1, B indicating a grade equivalent to Comparative Example 1, and C indicating a higher degree of color fading than Comparative Example 1.

[0053] [Setting ability] Each of the offset printing ink compositions of Examples 1 and 2 and Comparative Example 1 was applied to coated paper using an RI tester (manufactured by Akebono Seisakusho Co., Ltd.), and then immediately thereafter, the degree of offset printing adhesion to high-quality paper placed on the applied surface was visually confirmed using an ink setting time tester (manufactured by Tester Sangyo Co., Ltd.), and the time required for adhesion to no longer be observed was measured. The shorter this time, the better the setting ability. The results were evaluated on a three-level scale of A to C. Specifically, Comparative Example 1 was rated B, with A being a time shorter than Comparative Example 1, B being the same as Comparative Example 1, and C being a time longer than Comparative Example 1.

[0054] [On-press stability] For each offset printing ink composition of Examples 1, 2, and Comparative Example 1, the tack value was measured every minute using a digital incometer (manufactured by Toyo Seiki Seisakusho, Ltd.) under the following conditions: ink volume: 1.31 cc; room temperature: 25°C; roller temperature: 35°C; and rotation speed: 1200 rpm. In all Examples and Comparative Examples, the tack value increased as rotation began, peaked at a certain point, and then decreased. On-press stability was evaluated based on the time required for the tack value to reach its peak value. The time required for the tack value to reach its peak value can be considered to be the time required for ink peeling to occur on the incometer roller. Therefore, the longer the time required for the tack value to reach its peak value, the longer the time required for ink peeling to occur on the incometer roller, i.e., the higher the on-press stability can be considered to be. The time was 52.5 minutes for Example 1, 29.5 minutes for Example 2, and 25.5 minutes for Comparative Example 1. The results were evaluated on a three-level scale of A to C. Specifically, Comparative Example 1 was rated as B, a longer time than Comparative Example 1 was rated as A, a time equivalent to Comparative Example 1 was rated as B, and a shorter time than Comparative Example 1 was rated as C.

[0055] [Emulsification Limit Rate] Using a Lithotronic emulsification tester (manufactured by NOVOCONTROL), distilled water was added to 25 g of each of the offset printing ink compositions of Examples 1, 2, and Comparative Example 1 at a rate of 2 ml / min at 40°C and 1200 rpm, the amount of water at the time when the ink was saturated was measured, and the emulsification limit rate was calculated according to the following formula: Emulsification limit rate (%) = 100 × (amount of water at saturation (g) / amount of ink (g)) The results were evaluated on a two-level scale: B and C. Specifically, Comparative Example 1 was evaluated as B, and cases where the emulsification limit rate was higher or lower than Comparative Example 1 were evaluated as C.

[0056]

[0057] According to Table 2, Example 1 corresponds to a case in which all of the petroleum-based high-boiling point solvent (AF Solvent No. 7) was replaced with a biomass-derived α-olefin solvent, and Example 2 corresponds to a case in which the biomass-derived α-olefin solvent accounted for approximately 9% of the total amount of the petroleum-based high-boiling point solvent and the biomass-derived α-olefin solvent. However, it can be seen that these have performance equal to or better than Comparative Example 1, i.e., an offset printing ink composition using a conventional petroleum-based high-boiling point solvent.

[0058] This application claims priority based on Japanese Patent Application No. 2022-020987, filed February 15, 2022, and Japanese Patent Application No. 2022-051767, filed March 28, 2022, the disclosures of which are incorporated herein in their entireties.

[0059] The above describes embodiments of the present invention, but these are merely examples of the present invention, and various other configurations can also be adopted. Examples of reference embodiments are listed below. <1> An offset printing ink composition containing a biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher. <2> The offset printing ink composition according to <1>, wherein the hydrocarbon solvent is an α-olefin solvent. <3> The offset printing ink composition according to <2>, wherein the α-olefin solvent contains 1-hexadecene and 1-octadecene. <4> A method for producing an offset printed matter, comprising the steps of preparing paper as a substrate and printing the offset printing ink composition according to any one of <1> to <3> onto the paper.

Claims

1. A varnish for use in an offset printing ink composition, comprising: A varnish derived from biomass and containing a hydrocarbon solvent with a boiling point of 200°C or higher.

2. The varnish according to claim 1, wherein the biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher contains an α-olefin solvent.

3. 3. The varnish according to claim 2, wherein the α-olefin solvent contains 1-hexadecene and 1-octadecene.

4. The varnish according to claim 1 , wherein the content of the biomass-derived hydrocarbon solvent having a boiling point of 200° C. or higher is 1 part by mass or more and 90 parts by mass or less per 100 parts by mass of the varnish.

5. An offset printing ink composition containing the varnish according to any one of claims 1 to 3.

6. An offset printing ink composition comprising a biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher.

7. 6. The offset printing ink composition according to claim 5, wherein the content of the biomass-derived hydrocarbon solvent having a boiling point of 200°C or higher is 1 part by mass or more and 90 parts by mass or less per 100 parts by mass of the offset printing ink composition.

8. 6. The offset printing ink composition according to claim 5, wherein the time required for the tack value to reach a peak value, as evaluated by the following <Method 1>, is 26 minutes or more. <Method 1> The offset printing ink composition is applied to a digital incomer under the conditions of an ink amount of 1.31 cc, room temperature of 25° C., roller temperature of 35° C. and rotation speed of 1200 rpm, and the time required for the tack value to reach its peak is measured.

9. 6. The offset printing ink composition according to claim 5, wherein the density evaluated by the following <Method 2> is 2.00 or more. <Method 2> The offset printing ink composition is applied to coated paper using an RI tester, and then immediately dried in an oven at 120° C. for 15 seconds, and the color density of the applied surface is measured using a Gretag Macbeth Spectroeye.

10. A method for producing an offset printed matter, comprising the steps of: preparing a substrate; and offset printing the offset printing ink composition according to claim 5 onto the substrate.

11. The method for producing an offset printed matter according to claim 10, wherein the substrate is paper.