JP2015199777A - lithographic printing ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an offset ink composition excellent in fluidity of an ink, stability with time, drying property during printing, and stability on a printing machine while taking a global environment into consideration, and to achieve both of setting property and glossiness of a printed matter using the ink composition.SOLUTION: An offset ink composition comprising a binder resin, a pigment, and vegetable oils and/or a petroleum solvent as a solvent component is used, in which a fatty acid ester derived from a specific vegetable oil is included by 2 to 20%.

Description

The present invention relates to an offset ink composition used for printing books, flyers, catalogs, and the like. More specifically, the present invention is more excellent in drying property at the time of printing ink and stability on a printing machine, and the ink. The present invention relates to an oxidative polymerization type offset ink composition that can maintain both gloss and setability of a printed matter obtained by using CO2 and that can achieve CO ₂ reduction by reducing transportation mileage and has a low total environmental impact.

Conventional offset inks include synthetic resins such as rosin-modified phenolic resin, rosin-modified alkyd resin, petroleum resin-modified phenolic resin, vegetable oil such as linseed oil, tung oil, soybean oil, mineral oil, synthetic oil, and ink as required. In order to give flexibility and softness to the dry film, it consists of additives such as plasticizers and wax compounds, colorants and solvents for pigments and dyes, and the solvents used in these inks Aromatic solvents have been mainly used from the standpoint of solubility and dispersibility and printability (Patent Documents 1 and 2).
However, in recent years, inks mainly composed of oils such as the above-described mineral oils and aromatic solvents have a problem that odors of volatile vapors such as residual solvents are strong during production and printing and in printed materials. Therefore, from the viewpoint of environmental hygiene such as work environment and air pollution, the odor of volatile vapor is extremely low, and it is replaced with ink mainly composed of vegetable oil and non-aromatic solvents that have less environmental load such as work environment and air pollution. (Patent Documents 1 and 2).
That is, in Patent Documents 3 and 4, a printing ink composition comprising rosin-modified phenolic resin and vegetable oil-derived fatty acid ester as a solvent main component, significantly reducing VOC components compared with conventional inks, and having high-speed setting properties. Although a thing is proposed, the glossiness of the printed matter obtained using this ink falls.

In Patent Document 5, rosin-modified phenolic resin, rice bran oil and fatty acid monoester are used as main raw materials, and VOC components are greatly reduced compared to conventional inks. Printing inks with stability have been proposed, but their setability and drying properties are poor.

In patent document 6, although the offset ink using the rice bran oil which adjusted the iodine value to 100 or more is proposed, dryness and on-machine stability are inadequate.
Furthermore, in recent years, crops such as soybean oil have been diverted to bioethanol raw materials, and there are concerns that the price of soybean oil will rise and that a stable supply amount will be secured. On the other hand, with the rapid movement to reduce CO ₂ emissions on a global scale, the idea of eliminating decalcified materials and VOCs from ink components has become widespread. Moreover, the same concept applies to transportation fuel.

In terms of reducing CO ₂ emissions by shortening the distance between transportation / mileage, that is, the production / manufacturing sites and consumption areas of raw materials and products, etc., procure ink raw materials closer to the ink manufacturing area. This can contribute to the reduction of CO ₂ emissions.

  However, soybean oil used as a vegetable oil component is mainly imported from overseas harvested soybeans harvested in North and South America, and transport mileage is poor, which is undesirable for the environment.

JP 2006-249385 A JP 2005-290084 A JP 2002-69354 A JP 2002-155227 A JP 2005-330317 A JP 2003-96375 A

  The present invention balances the glossiness and setability of an offset ink composition excellent in drying properties during printing of ink and stability on a printing machine and printed matter obtained using the same while taking into consideration the global environment. Is to maintain.

As a result of diligent research to solve the above problems, in an offset ink composition containing a binder resin, a vegetable oil, and a pigment, the offset ink composition containing a specific vegetable oil-derived fatty acid ester exhibits stability over time and at the time of printing. It is excellent in drying property and stability on a printing press, and the gloss and setting properties of printed matter obtained using the ink are not impaired. Furthermore, typical vegetable oils used for the synthesis of fatty acid esters derived from this specific vegetable oil can be procured in Japan, reducing CO ₂ emissions by reducing transportation mileage and reducing the total environmental impact. As a result, the present invention has been completed.

That is, the present invention is an offset ink composition containing a fatty acid ester (A), a binder resin (B), a pigment (C), and a vegetable oil (D), and the following (1), (2 ).
(1) The fatty acid ester (A) is a mixture of fatty acid esters represented by the general formula (1).
General formula (1)
R1-COO-R2
R1 represents a saturated hydrocarbon group having 14 to 18 carbon atoms or an unsaturated hydrocarbon group having 14 to 18 carbon atoms having no triple bond, and R2 represents a linear saturated hydrocarbon group having 1 to 8 carbon atoms. Or represents a branched saturated hydrocarbon group.
(2) Fatty acid ester (A)
15 to 30% by weight of fatty acid ester (a16_0) in which R1 is a saturated hydrocarbon group having 16 carbon atoms,
35 to 45% by weight of fatty acid ester (a18_1), which is an unsaturated hydrocarbon group having 18 carbon atoms and R1 having one double bond,
25 to 45% by weight of a fatty acid ester (a18_2), which is an unsaturated hydrocarbon group having 18 carbon atoms, in which R1 has two double bonds,
and,
Fatty acid ester (a18_3), which is an unsaturated hydrocarbon group having 18 carbon atoms, in which R1 has three double bonds, is 1.0% or less.
(3) Fatty acid ester (A) is 2 to 20% by weight in the total amount of the offset ink composition.

Furthermore, the present invention. The binder resin is a rosin-modified phenol resin having a weight average molecular weight of 10,000 to 100,000, and relates to the above oxidation polymerization type offset ink composition.

 The present invention relates to printing obtained by printing the above oxidation polymerization type offset ink composition on a substrate.

The oxidative polymerization type offset ink composition provided by the present invention is superior in drying property at the time of printing of ink and stability on a printing press in printing of books, leaflets, catalogs, etc., and uses the ink. In addition, the present invention relates to an oxidation polymerization type offset ink composition that can maintain both gloss and setability of a printed matter obtained in addition, and that can achieve CO ₂ reduction by reducing transportation mileage and has a low total environmental load.

  Next, the present invention will be described more specifically with reference to preferred embodiments.

The present invention is an offset ink composition containing a fatty acid ester (A), a binder resin (B), a pigment (C), a vegetable oil (D), and a petroleum solvent (E). These combinations can solve the problems of the present invention.

The fatty acid ester (A) in the present invention is a mixture of fatty acid esters represented by the general formula (1). Specific examples include rice oil methyl ester, rice oil butyl ester, rice oil isohexyl ester, and the like.
General formula (1)
R1-COO-R2
(R1 represents a saturated hydrocarbon group having 14 to 18 carbon atoms or an unsaturated hydrocarbon group having 14 to 18 carbon atoms having no triple bond, and R2 represents a linear saturated hydrocarbon having 1 to 8 carbon atoms. Represents a group or a branched saturated hydrocarbon group.)

If R1 is a saturated hydrocarbon group having less than 14 carbon atoms or an unsaturated hydrocarbon group having less than 14 carbon atoms, the dissolving power of the fatty acid ester is too high, and there is concern about adverse effects on printing materials such as blankets and rubber rollers. The R1 is a saturated hydrocarbon group having a carbon number greater than 18, an unsaturated hydrocarbon group having a carbon number greater than 18, a linear saturated hydrocarbon group having 9 or more carbon atoms, or a branched saturated hydrocarbon group having 9 or more carbon atoms. When it exists, since the dissolving power of fatty acid ester (A) is insufficient, it is not preferable.

Furthermore, in the present invention, it is necessary to be a specific fatty acid ester.
That is, in the total amount of fatty acid ester (A),
15 to 30% by weight (preferably 18 to 24% by weight) of a fatty acid ester (a16_0) in which R1 is a saturated hydrocarbon group having 16 carbon atoms,
35 to 45% by weight (preferably 38 to 43% by weight) of fatty acid ester (a18_1), which is an unsaturated hydrocarbon group having 18 carbon atoms and R1 having one double bond,
And fatty acid ester (a18_2), which is an unsaturated hydrocarbon group having 18 carbon atoms, in which R1 has two double bonds, needs to be contained in an amount of 25 to 45% by weight (preferably 35 to 40% by weight).

When the fatty acid ester (A) is outside this range, the printed matter after drying the ink is inferior in friction resistance and gloss, and the stability of the ink in the storage container with time is not preferable.

Further, the fatty acid ester (a18_3) in which R1 is an unsaturated hydrocarbon group having 18 carbon atoms having three double bonds must be 1.0% by weight or less in the total amount of the fatty acid ester (A). Yes, preferably 0.7% by weight or less, more preferably 0.5% by weight or less, and ideally 0% by weight. If the fatty acid ester (a18_3) is not controlled within this range, it is not preferable because the temporal stability of the ink in the storage container is extremely inferior.

The fatty acid ester (A) in the present invention is preferably made from a vegetable oil represented by the general formula (2) as a raw material. By using the following vegetable oil as a raw material, the fatty acid ester (A) can be efficiently purified.

（一般式(２)において、Ｒ３、Ｒ４およびＲ５は、各々炭素数１４〜１８の飽和炭化水素基または三重結合を有さない炭素数１４〜１８の不飽和炭化水素基を表す。
ただし、(Ｒ３＋Ｒ４＋Ｒ５)の全量に対して、炭素数１６の飽和炭化水素基のモル比率が１０〜３０％であり、二重結合を１つ有する炭素数１８の不飽和炭化水素基のモル比率が３５〜４５％であり、二重結合を２つ有する炭素数１８の不飽和炭化水素基のモル比率が２５〜４５％であり、さらに、二重結合を３つ有する炭素数１８の不飽和炭化水素基のモル比率が１．０％以下である。） General formula (2)

(In the general formula (2), R3, R4 and R5 each represents a saturated hydrocarbon group having 14 to 18 carbon atoms or an unsaturated hydrocarbon group having 14 to 18 carbon atoms having no triple bond.
However, with respect to the total amount of (R3 + R4 + R5), the molar ratio of the saturated hydrocarbon group having 16 carbon atoms is 10 to 30%, and the molar ratio of the unsaturated hydrocarbon group having 18 carbon atoms having one double bond is 35 to 45%, the molar ratio of unsaturated hydrocarbon group having 18 carbon atoms having 2 double bonds is 25 to 45%, and further unsaturated carbon having 18 carbon atoms having 3 double bonds The molar ratio of hydrogen groups is 1.0% or less. )

In the present invention, the vegetable oil used as a raw material for the fatty acid ester (A) is preferably a vegetable oil having an iodine value of 70 to 130 (mg / 100 mg), more preferably a vegetable oil having an iodine value of 90 to 120 (mg / 100 mg). . By limiting the range of the iodine value, it is possible to increase the drying property by oxidative polymerization of the ink film, which is particularly effective for a sheet-fed printing method that does not use a hot air dryer.

As for the method of obtaining the vegetable oil represented by the general formula (2), it is desirable that raw material production and oil extraction are performed domestically from the viewpoint of reducing CO ₂ emission by shortening transportation mileage. Procurement of raw materials produced in Japan can significantly reduce transportation fuel and CO ₂ emissions compared to vegetable oil represented by soybean oil harvested and oiled overseas. Can be made smaller. From this point of view, there are significant industrial advantages. For example, it may be obtained as rice bran oil produced and squeezed domestically, but other vegetable oils may be refined and processed into general formula (2).

Examples of the method for producing the fatty acid ester (A) used in the present invention include the following, but are not limited thereto.
(1) Fatty acid monoester obtained by ester reaction of triglyceride of glycerin and fatty acid and saturated or unsaturated alcohol (2) Fatty acid monoester obtained by direct ester reaction of fatty acid and monoalcohol of vegetable oil

  In the present invention, the fatty acid ester (A) needs to be 2 to 20% by weight, preferably 4 to 12% by weight in the total amount of the offset ink composition. If the fatty acid ester (A) is less than 2% by weight, the setability is poor. On the other hand, if it exceeds 20% by weight, the stability on the printing press deteriorates.

Examples of the binder resin (B) that can be used in the present invention include phenol resins (phenol resins, rosins, cured rosins, rosin-modified phenol resins using rosins such as polymerized rosins, etc.), maleic resins (rosins) Modified maleic acid resins, rosin ester resins, etc.), alkyd resins or modified alkyd resins, petroleum resins, and the like. These may be used alone or in combination of two or more.
In particular, the binder resin preferably used in the present invention has an acid value of 5 to 30 (mg KOH / g), a weight average molecular weight of 10,000 to 100,000, preferably 20,000 to 80,000, and a softening point by a ring and ball method of 120 to 120. A rosin-modified phenolic resin having a temperature of 300 ° C., preferably 120 to 280 ° C. is desirable.
When the weight average molecular weight is 10,000 to 100,000, viscoelasticity, fluidity and gloss are suitable.

The rosin-modified phenolic resin in the present invention is obtained by reacting rosin which is a resin acid, resole which is a condensate of alkylphenol and formalin, and a polyhydric alcohol, and a third component such as maleic acid is added as necessary. Sometimes. The blending ratio of rosin and resole is one of the important factors controlling the physical properties of the resin. The blending ratio of rosin in the rosin-modified phenolic resin according to the present invention is desirably 60% by weight or more and 70% by weight or less, and preferably 62% by weight or more and 67% by weight or less. If the ratio is less than 60% by weight, the resole has excessive alkyl groups. As a result, the solubility of the resin in the solvent becomes excessive, making it difficult to achieve the desired high viscosity of the ink. Since the alkyl group of the resole is reduced and the solubility of the resin in the solvent is too bad, the solvent may be separated from the ink.

In addition, any inorganic and organic pigments can be used as the pigment (C) used in the present invention. Examples of inorganic pigments include chrome yellow, zinc yellow, bitumen, barium sulfate, cadmium red, titanium oxide, zinc white, petal, alumina white, calcium carbonate, ultramarine, carbon black, graphite, aluminum powder, and organic pigments. As such, pigments used in offset inks such as azo, phthalocyanine, quinacridone, anthraquinone, and dioxazine are equivalent. Regarding organic pigments, for example, copper phthalocyanine pigments (CI Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, CI Pigment Green 7, 36) Monoazo pigments (CI Pigment Red 3, 4, 5, 23, 48: 1, 48: 2, 48: 3, 48: 4, 49: 1, 49: 2, 53: 1, 57: 1 ), Disazo pigments (CI Pigment Yellow 12, 13, 14, 17, 83), anthraquinone pigments (CI Pigment Red 177), quinacridone pigments (CI Pigment Red 122, CI) Pigment Violet 19), dioxazine pigments (CI Pigment Violet 23), and the like. Not intended to be.

  The vegetable oils (D) in the present invention include asiatic oil, linseed oil, eno oil, jute oil, olive oil, cacao oil, kapok oil, kayak oil, mustard oil, kyounin oil, kiri oil, kukui oil, walnut oil, Poppy oil, sesame oil, safflower oil, Japanese radish seed oil, soybean oil, daikon oil, camellia oil, corn oil, rapeseed oil, niger oil, nuka oil, palm oil, castor oil, sunflower oil, grape seed oil, gentian oil Those derived from vegetable oils such as pine seed oil, cottonseed oil, coconut oil, peanut oil, dehydrated castor oil, thermal polymerization oils, oxygen-blown polymerization oils, and the like can be used in combination. These may be used alone or in combination of two or more. The vegetable oils are preferably contained in an amount of 10 to 50% by weight, preferably 20 to 30% by weight, based on the total amount of ink. If it is less than 20% by weight, the gloss of the printed matter is inferior.

The petroleum solvent (E) in the present invention is a crude oil-derived solvent (petroleum solvent) having an aromatic hydrocarbon content of 1% by weight or less, and has a boiling point of 260 to 350 ° C., preferably 280 ° C. What is in the range of -340 degreeC is good. When the boiling point of petroleum-based solvents is less than 260 ° C, the solvent evaporation of the ink on the printing machine increases, and the transferability of the ink to rollers, blankets, plates, etc. deteriorates due to the deterioration of the fluidity of the ink. It is not preferable. Further, when the boiling point of the petroleum solvent used in combination exceeds 350 ° C., the drying property of the ink is inferior. The petroleum solvent used in the present invention is desirably contained in an amount of 5 to 20% by weight, preferably 7 to 18% by weight, based on the total amount of the ink, if necessary.
Further, an aniline point of 75 ° C to 95 ° C is suitable for the petroleum solvent. When the aniline point is less than 75 ° C., the ability to dissolve the resin is too high, the ink viscosity becomes too low, and the stain resistance is not sufficient. Also, if the aniline point exceeds 95 ° C, the ability to dissolve the resin is too low, the ink viscosity becomes too high, the ink fluidity is poor, and ink tends to accumulate on the rollers, plates, and blankets. Therefore, it is not preferable.

Furthermore, the offset ink composition of the present invention includes a gelling agent, a pigment dispersant, a metal dryer, a drying inhibitor, an antioxidant, a friction improver, an anti-set-off agent, and a nonionic sea surface activity as required. An additive such as an agent and a polyhydric alcohol can be conveniently used.
In the present invention, the metal dryer is an oxidative polymerization catalyst that promotes oxidative polymerization, and includes acetic acid, propionic acid, butyric acid, isopentanoic acid, hexanoic acid, 2-ethylbutyric acid, naphthenic acid, octylic acid, nonanoic acid, decanoic acid, 2-ethylhexanoic acid, isooctanoic acid, isononanoic acid, lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, neodecanoic acid, versatic acid, secanoic acid, tall oil fatty acid, linseed oil fatty acid, soybean oil fatty acid, dimethylhexa Metal salts of organic carboxylic acids such as noic acid, 3,5,5-trimethylhexanoic acid, dimethyloctanoic acid, such as calcium, cobalt, lead, iron, manganese, zinc, zirconium, salt, etc. Known and publicly available compounds can be used to promote printing ink surface and internal curing Therefore, a plurality of these can be used in combination as appropriate.

The antioxidant is a polymerization inhibitor having an inhibitory effect on the oxidative polymerization reaction, and hydroquinone derivatives represented by hydroquinone, 2-methylhydroquinone, 2-tert-butylhydroquinone, etc. -Denotes phenolic compounds typified by tert-butyl-4-hydroxytoluene and the like, vitamin compounds having an antioxidant action typified by ascorbic acid, tocopherol, etc., and these are arbitrarily used alone or in combination of two or more. Can be used.

As auxiliary agents, anti-friction agents, anti-blocking agents, slip agents, pigment dispersants, carnauba wax, beeswax, lanolin wax, montan wax, paraffin wax, microcrystalline wax, natural wax, Fischer-Tropsch synthetic wax, Synthetic waxes such as polyethylene wax, polypropylene wax, polytetrafluoroethylene wax and polyamide wax, silicone additives, leveling agents and the like can be used as appropriate.

In the offset ink composition, the proportion of each component is 5 to 30% by weight of pigment, 20 to 50% by weight of binder resin, 4 to 12% by weight of fatty acid ester, 20 to 40% by weight of vegetable oils, petroleum solvent 0 to 20% by weight, 0 to 3% by weight of dryer, 0 to 4% by weight of antioxidant, 0 to 10% by weight of other additives, and the like.

In the offset ink composition of the present invention, the viscosity at 25 ° C. and a shear rate of 100 / s is preferably 120.0 Pa · s or less, more preferably 30.0 Pa · s to 100.0 Pa · s, with a cone plate viscometer. If the viscosity is greater than the above values, the fluidity and transferability will decrease, so the stability of the ink supplied to the roller will be poor, and the printing workability will be hindered, and the leveling property of the ink transferred to the paper will be reduced. It is not preferable because it deteriorates and causes quality problems such as gloss deterioration. In addition, the tack value of the ink increases with the viscosity, so that paper peeling or paper separation failure is likely to occur, and paper dust accumulates on the blanket, which is not preferable because stable printing workability such as transfer failure cannot be secured.

The offset ink composition of the present invention is used for lithographic printing, but can be applied to coating methods such as roll coaters and knife coaters, or printing methods such as gravure printing, letterpress printing, and silk screen printing, as long as they do not depart from the idea. Is also applicable.
In the present invention, the weight average molecular weight was measured by gel permeation chromatography (HLC-8020, hereinafter referred to as GPC) manufactured by Tosoh Corporation. A calibration curve was prepared with a standard polystyrene sample. Tetrahydrofuran was used as the eluent, and three TSKgel SuperHM-M (manufactured by Tosoh Corporation) were used as the column. The measurement was performed at a flow rate of 0.6 ml / min, an injection volume of 10 μl, and a column temperature of 40 ° C.
Furthermore, in the present invention, “molecular weight” means a weight average molecular weight unless otherwise specified.

EXAMPLES Next, although an Example demonstrates this invention further in detail, the scope of the present invention is not limited by these Examples. In the present invention, “part” represents “part by weight” and “%” represents “% by weight”.

(Resol adjustment)
P-octylphenol 1000 parts, 35% formalin 850 parts, 93% sodium hydroxide 60 parts and toluene 1000 parts were added to a four-necked flask equipped with a stirrer, cooler and thermometer, and reacted at 90 ° C. for 6 hours. It is dripping. Thereafter, 125 parts of 6N hydrochloric acid and 1000 parts of tap water were added, stirred and allowed to stand, and the upper layer part was taken out to obtain 2000 parts of a toluene solution of a resol type phenol resin having a nonvolatile content of 49%. Y.

(Production Example 1 of rosin-modified phenolic resin)
A four-necked flask equipped with a stirrer, a condenser with a water separator, and a thermometer was charged with 1000 parts of gum rosin, dissolved at 200 ° C. while blowing nitrogen gas, and 1360 parts of resole liquid Y was added to remove toluene. However, after reacting at 230 ° C. for 4 hours, 100 parts of glycerin was added, and esterified at 250 to 260 ° C. until the acid value was 25 or less, and a rosin having a weight average molecular weight of 40000, an acid value of 21.7, and a softening point of 170 ° C. A modified phenolic resin A (hereinafter referred to as “resin A”) was obtained.

(Production Example 2 of rosin-modified phenolic resin)
A four-necked flask equipped with a stirrer, a condenser with a water separator and a thermometer was charged with 1000 parts of gum rosin, dissolved at 200 ° C. while blowing nitrogen gas, and 1490 parts of resole liquid Y was added to remove toluene. Then, after reacting at 230 ° C. for 4 hours, 115 parts of glycerin was charged and esterified at 250 to 260 ° C. until an acid value of 25 or less, and a rosin having a weight average molecular weight of 70,000, an acid value of 19.5, and a softening point of 180 ° C. Modified phenol resin B (hereinafter referred to as resin B) was obtained.

(Production Example 3 of rosin-modified phenolic resin)
A four-necked flask equipped with a stirrer, a condenser with a water separator, and a thermometer was charged with 1000 parts of gum rosin, dissolved at 200 ° C. while blowing nitrogen gas, and 1370 parts of resole liquid Y was added to remove toluene. Then, after reacting at 230 ° C. for 4 hours, 130 parts of glycerin was charged and esterified at 250 to 260 ° C. until the acid value was 25 or less, and a rosin having a weight average molecular weight of 140000, an acid value of 18.5 and a softening point of 190 ° C. A modified phenolic resin C (hereinafter referred to as “resin C”) was obtained.

(Fatty acid ester A production example)
A four-neck flask with a stirrer, Liebig condenser and thermometer was charged with 14 parts of rice oil, 81 parts of methanol and 5 parts of sodium hydroxide, heated to 60 ° C., stirred at the same temperature for 6 hours, and then allowed to cool. Fatty acid ester A was obtained.

(Fatty acid ester B production example)
A four-neck flask with a stirrer, Liebig condenser and thermometer was charged with 14 parts of soybean oil, 81 parts of methanol and 5 parts of sodium hydroxide, heated to 60 ° C., stirred at the same temperature for 6 hours, and allowed to cool. Fatty acid ester B was obtained.

(Varnish 1 production example)
Stirrer, Liebig condenser, 4-neck flask with thermometer, resin A (weight average molecular weight 40000, acid value 21.7, softening point 170 ° C.) 45 parts, fatty acid ester A 10 parts, soybean oil 24 parts, AF solvent 5 No. (Shin Nippon Oil Co., Ltd.) 20 parts, ALCH (ethyl acetoacetate aluminum diisopropoxide, Kawaken Fine Chemical Co., Ltd. gelling agent) 1 part, charged to 190 ° C, the same temperature for 1 hour After stirring, the mixture was allowed to cool to obtain varnish 1.
(Manufacturing example of varnish 2-6)
Based on the composition in Table 1, varnishes 2 to 6 were obtained by the same varnish production method as in Varnish Production Example 1.
However, C16: 0 in Table 1 shows the molar ratio of C16 saturated hydrocarbon, C18: 1 shows the molar ratio of C18 unsaturated hydrocarbon having one double bond, C18 : 2 shows the molar ratio of the C18 unsaturated hydrocarbon having two double bonds.

(Base ink and ink manufacturing)
17 parts of LIONOL BLUE FG7330 (manufactured by Toyocolor Co., Ltd.), 60 parts of varnish 1, 5 parts of fatty acid ester A, 82 parts in total on 3 rolls, and kneaded twice with 3 rolls at 60 ° C As a result, the pigment particles were dispersed to 7.5 μm or less, and the base ink 1 was obtained.
Next, 5 parts of soybean oil, 6.3 parts of AF Solvent No. 5, 5 parts of wax compound (manufactured by Toyo Ink Co., Ltd., new anti-friction compound), metal dryer (Toyo Ink Co., Ltd.) 1.5 parts of MK dryer) and 0.2 parts of drying inhibitor (manufactured by Toyo Ink Co., Ltd., drying inhibitor CP) were added to obtain about 100 parts by weight of Ink 1 of the Example.

A base ink was prepared by the same base ink preparation method as described above with the formulation shown in Table 2, and the fatty acid ester, soybean oil, linseed oil, AF solvent No. 5, wax compound, metal dryer, About 100 parts of inks 2-3 of the examples and inks 1-3 of the comparative examples were obtained by adding a drying inhibitor.

(Evaluation results)
In the sheet-fed inks of Examples 1 and 2 and Comparative Examples 1 to 5, the setability, gloss, fluidity, drying property, on-machine stability, and stability over time were evaluated, and the results are shown in Table 2. .

<Evaluation method for setability>
The ink was developed on the coated paper with an RI tester (manufactured by Meisei Co., Ltd.), and high quality paper was superimposed on the developed surface. The set completion time was the time when the ink no longer adhered to the high-quality paper, and the evaluation was performed based on the following evaluation criteria.
(Evaluation criteria)
◎: Within 8 minutes ○: 8 minutes or more, less than 14 minutes △: 14 minutes or more, less than 20 minutes ×: 20 minutes or more

<Glossy evaluation method>
The ink was developed on coated paper with an RI tester (manufactured by Meisei Seisakusho Co., Ltd.), and evaluation was performed based on the gloss meter value.
(Evaluation criteria)
◎: 50 or more ○: 45 or more, less than 50 Δ: 40 or more, less than 45 minutes x: 40 or less

<Measurement method of fluidity>
2.1 ml of ink was set in a hemispherical container and allowed to stand at 40 ° C. for 1 hour, then the ink was dropped on a tilted plate inclined at 60 °, and the length of flow for 10 minutes was measured. Evaluation was performed based on the following evaluation criteria.
(Evaluation criteria)
◎: 80 mm or more ○: 70 mm or more, less than 80 mm Δ: 50 mm or more, less than 70 mm x: less than 50 mm

<Method of measuring dryness>
The ink was developed on coated paper by using an RI tester (manufactured by Meiko Seisakusho Co., Ltd.), and sulfuric acid paper was layered on the developed surface. The drying time was the time when the ink no longer adhered to the sulfuric acid paper, and the evaluation was performed based on the following evaluation criteria.
(Evaluation criteria)
◎: Less than 6 hours ○: 6 hours or more, less than 8 hours Δ: 8 hours or more, less than 10 hours ×: 10 hours or more

<Measurement method of on-board stability>
After the ink was developed on a glass plate with a 75 μm applicator, the drying time was examined by finger touch every 30 minutes under conditions of 40 ° C. and humidity of 52%. The drying time was the time when the ink no longer adhered to the finger, and the evaluation was performed based on the following evaluation criteria.
(Evaluation criteria)
◎: 12 hours or more ○: 10 hours or more, less than 12 hours Δ: 6 hours or more, less than 10 hours ×: less than 6 hours

<Measurement method of stability over time>
The ink viscosity (Pa · s) at 25 ° C. and a share rate of 117 / s was measured by HAAKE Rheopress 600 (manufactured by Thermo ELECTRON CORPORATION). Then, it put into the airtight container, purged with nitrogen, closed the lid | cover, and stored in 90 degreeC oven for 1 week. After one week, the ink was removed from the oven and the ink viscosity was measured again. The difference in ink viscosity before and after oven storage was determined and evaluated based on the following evaluation criteria. The smaller the amount of change in viscosity, the better the stability over time.
(Evaluation criteria)
◎: Less than 10 Pa · s ○: 10 Pa · s or more, less than 15 Pa · s Δ: 15 Pa · s or more, less than 20 Pa · s ×: 20 Pa · s or more

  From the results shown in Table 2, it was found that all of the setability, gloss, fluidity, drying property, on-machine stability, and stability over time were well balanced and excellent.

Claims (3)

An offset ink composition comprising a fatty acid ester (A), a binder resin (B), a pigment (C), and a vegetable oil (D), characterized by the following (1) and (2) Ink composition.
(1) The fatty acid ester (A) is a mixture of fatty acid esters represented by the general formula (1).
General formula (1)
R1-COO-R2
R1 represents a saturated hydrocarbon group having 14 to 18 carbon atoms or an unsaturated hydrocarbon group having 14 to 18 carbon atoms having no triple bond, and R2 represents a linear saturated hydrocarbon group having 1 to 8 carbon atoms. Or represents a branched saturated hydrocarbon group.
(2) Fatty acid ester (A)
15 to 30% by weight of fatty acid ester (a16_0) in which R1 is a saturated hydrocarbon group having 16 carbon atoms,
35 to 45% by weight of fatty acid ester (a18_1), which is an unsaturated hydrocarbon group having 18 carbon atoms and R1 having one double bond,
25 to 45% by weight of a fatty acid ester (a18_2), which is an unsaturated hydrocarbon group having 18 carbon atoms, in which R1 has two double bonds,
and,
Fatty acid ester (a18_3), which is an unsaturated hydrocarbon group having 18 carbon atoms, in which R1 has three double bonds, is 1.0% or less.
(3) Fatty acid ester (A) is 2 to 20% by weight in the total amount of the offset ink composition. 2. The oxidation polymerization type offset ink composition according to claim 1, wherein the binder resin is a rosin-modified phenol resin having a weight average molecular weight of 10,000 to 100,000.  The printing formed by printing the oxidation polymerization type offset ink composition of Claim 1 or 2 on a base material.