JP5679648B2 - Osmotic dry ink ink composition for offset printing - Google Patents

Description

The present invention relates to a penetrating dry offset black ink composition printed in a field using a printing paper having a high fiber permeability and a coarse fiber density, such as a newspaper or a telephone book. More specifically, the present invention relates to a penetrating dry type offset ink ink for offset printing that has a bluish hue, high blackness, and good printability without using a complementary colorant.

Offset printing is a printing method characterized in that oil-based ink is printed on a printing plate without irregularities by utilizing the property of repelling water. In the printing plate, an oleophilic image portion and a hydrophilic non-image portion are formed instead of unevenness. In printing, first, dampening water is supplied to the printing plate, and the non-image area is wetted with dampening water. Next, when oil-based ink is supplied to the printing plate, in the non-image area wetted with dampening water, the ink does not adhere due to the repulsion of oil and water, and the oil-based ink adheres only to the image area. An ink image can be formed on the printing plate. Furthermore, the ink image of the printing plate is sequentially transferred to a blanket and paper for printing.

The offset printing method is characterized in that the plate making of the printing plate is relatively simple, and the obtained printed matter has high cosmetic properties and is suitable for printing a large amount of printed matter at a high speed. Therefore, taking advantage of these features, from fields requiring high cosmetics such as brochures, posters, and calendars, to fields such as newspapers, magazines, and telephone books that can be printed in large quantities even with moderate print quality. Widely used.

Among them, printing of newspapers and telephone books generally uses porous printing paper with coarse fibers due to the feature of printing in large quantities at a reduced cost. Correspondingly, penetrating and drying inks that can be set or dried even during high-speed printing are used by allowing the fluid component to permeate into the paper immediately after printing. The printing of newspapers and telephone books is a major feature that there are many types, and black ink is the main feature. In addition, because the paper quality is printed on printing paper with low whiteness on a highly penetrating surface, the contrast is high with respect to the ground color, and the paper surface has sufficient blackness even after the penetrating component has penetrated. Printing performance is required. Therefore, penetrating dry ink ink composition for offset printing has high blackness, bluish hue (contrast is improved with respect to the background color of paper), and printing that does not cause a decrease in density (dry down) due to penetration. It is necessary to have aptitude.

Such ink performance greatly depends on the carbon black used as the colorant. Carbon black has a structure in which primary particles immediately after formation further form aggregates, and the characteristics differ depending on the primary particle diameter and the size of the aggregates. Specifically, as the primary particle size increases to a small particle size, medium particle size, and large particle size, the bluish hue improves dispersibility and fluidity, but the coloring power (density and blackness) decreases. Tend to. Further, as the aggregate becomes larger as a small aggregate, a medium aggregate, and a large aggregate, the dispersibility and fluidity are improved, but the blackness tends to decrease. Up to now, in the ink, overall performance such as blackness, fluidity, and printability has been emphasized, and in general, medium particle diameter and medium aggregate carbon black have been used. In addition, the same colorant may have a small particle size and small aggregate for paint applications, a medium particle size and small aggregate for plastic applications, and a large particle size and small to large aggregate for rubber reinforcement applications. Are within the preferred range.

However, when the medium particle size suitable for the ink application and the medium aggregate carbon black are dispersed, the hue becomes reddish or yellowish, and it is difficult to obtain high blackness. Therefore, the conventional penetrating dry offset ink ink composition for offset printing has been adjusted by adding expensive complementary colors such as indigo pigments and dyes in order to make reddish and yellowish hues bluish (for example, , See Patent Document 1).

However, with this penetrating dry offset ink ink composition for offset printing, the problem of dry-down remains unsolved, and a phenomenon in which a sufficient bluish hue cannot be maintained when dry-down occurs is observed, In addition, there was an economical disadvantage due to the cost increase. In view of this, studies have been made to provide ink required performance with carbon black itself without using a complementary colorant.

As described above, the blackness and hue of the black ink depend on the primary particle size of the carbon black used and the size of the aggregates. The occurrence of drydown is also affected by the fluidity of the ink and indirectly depends on the primary particle size and the size of the aggregate.
In the past, techniques for improving blackness, bluish hue, and the like by limiting the numerical values of the primary particle diameter and the size of aggregates have been disclosed. The primary particle size of carbon black is often expressed by the nitrogen adsorption specific surface area, and the size of the aggregate is often expressed by the DBP oil absorption. For example, the specific coloring power: 80 to 115%, the nitrogen adsorption ratio surface area: 50~100m ² / g, DBP oil absorption: 60~100cm ³ / 100g (is in the range suitable for ink applications, a relatively low coloring power in which the large particle size, small to large aggregates), centrifuged A carbon black for printing ink having an aggregate diameter (Dmod) of 140 to 230 nm by a sedimentation method (Patent Document 2) has been proposed. The ratio tinting strength: 80% to 95%, the nitrogen adsorption specific surface area: 60~120cm ³ / g, DBP oil absorption: it 80~120cm range suitable for carbon black (ink applications with ^3/100 g, in which Lower printing strength, large particle size, small to large aggregate), rosin-modified phenolic resin, offset printing ink containing a solvent (Patent Document 3) and the like have been proposed.

Further, the above-described ink composition for offset printing solves the problem of insufficient blackness after printing due to dry-down, and as a penetrating dry type ink ink composition for offset printing with a more bluish hue, coloring power: 50 to 80 %, nitrogen adsorption specific surface area: 30 to 50 m ² / g, DBP oil absorption: the extent suitable for the carbon black (rubber reinforcing applications with 100~140cm ³ / 100g, low coloring power than among them, large particle size, large coagulation Aggregate), rosin-modified phenol resin, and offset printing ink containing a solvent (Patent Document 4) are also known.

However, no matter how much the hue and drydown performance are improved, the overall performance as a printing ink composition must be good. To that end, carbon black has an ink composition that satisfies both the blackness, fluidity and dispersibility, which are basically incompatible with each other, and has the feature of a blue hue and low dry-down. Things are required.

Japanese Patent Laid-Open No. 06-192996 Japanese Patent Laid-Open No. 07-018200 JP 2006-282774 A JP 2008-163063 A

Therefore, an object of the present invention is to suppress dry-down, bluish hue and high black color when printed in a field using a high-penetration printing paper having a coarse fiber density, such as a newspaper or a telephone book. Another object of the present invention is to provide a penetrating dry type black ink composition for offset printing that has a good degree of printability.

As a result of diligent studies to solve the above problems, the present inventors have found that neutral carbon black having a low coloring power, a large particle size, and a small aggregate that are not generally used in ink applications, and a gilsonite resin as a dispersion aid. It has been found that by using a combination of at least one selected from petroleum resins and heavy oils, the original bluish hue of carbon black can be utilized and the low coloring power can be improved. Specifically, the inventors have found that the above combination can realize good dispersion stability and fluidity, high blackness, and low dry-down with a bluish hue, and have led to the present invention.

That is, the present invention is a (1) ratio tinctorial strength 50% to 70%, average primary particle diameter 65～100Nm, nitrogen adsorption specific surface area 20 to 40 m ² / g, and, DBP oil absorption of 60 to 100 ^[cm 3/100 g Neutral carbon black, (2) rosin modified phenolic resin and / or rosin modified maleic acid resin, (3) at least one selected from the group consisting of gilsonite resin, petroleum resin and heavy oil, and (4) oil The present invention relates to a penetrating dry ink ink composition for offset printing characterized by containing a component.
(3) At least one selected from the group consisting of (3) Gilsonite resin, petroleum resin and heavy oil is heavy oil and Gilsonite resin and / or petroleum resin, and the heavy oil and Gilsonite resin and / or The total content with the petroleum resin is preferably 1 to 150 parts by mass with respect to 100 parts by mass of the neutral carbon black.
In addition, at least one selected from the group consisting of (3) the above-mentioned gilsonite resin, petroleum resin and heavy oil is gilsonite resin and / or petroleum resin, and the content of the gilsonite resin and / or petroleum resin is It is preferable that it is 1-60 mass parts with respect to 100 mass parts of content of neutral carbon black.
The (4) oil component is preferably at least one selected from the group consisting of non-aromatic petroleum solvents, vegetable oils, and fatty acid ester compounds derived from vegetable oils.
Hereinafter, the penetrating dry ink ink composition for offset printing of the present invention will be described in detail.

The penetrating dry offset ink ink composition of the present invention comprises (1) a specific neutral carbon black, (2) a rosin-modified phenol resin and / or a rosin-modified maleic resin, (3) a gilsonite resin, a petroleum resin, and It contains at least one selected from the group consisting of heavy oils, and (4) an oil component.

The neutral carbon black constituting the black ink composition for penetrating dry offset printing of the present invention has a specific coloring power of 50 to 70%, an average primary particle size of 65 to 100 nm, a nitrogen adsorption specific surface area of 20 to 40 m ² / g, and a neutral carbon black pH6.0~8.0 a DBP oil absorption of 60~100 ^cm 3 / 100g.
The specific coloring power, nitrogen adsorption specific surface area, and DBP oil absorption are all defined in accordance with JIS K 6217.
The average primary particle diameter is an arithmetic average value of particle diameters obtained by observing particles with an electron microscope.

Neutral carbon black having the above characteristic values is originally classified as a rubber reinforcement application, and among them, it is characterized by being in a range of lower coloring power, large particle diameter, and small aggregates. is there.
As the relationship between these individual characteristic values and the performance of the obtained ink ink composition for osmotic dry offset printing, first, when a material having a low specific coloring power is used, both the density and blackness of the ink composition are lowered. Tend. On the other hand, when the average primary particle size of the carbon black is increased, the bluish hue becomes stronger, and it is easy to obtain preferable results for the purpose of the present invention. However, it is known that the specific coloring power is lowered. . Therefore, when carbon black having a large average primary particle size is used, there remains a problem of how to improve density and blackness.
Therefore, in the present invention, the average primary particle diameter and the nitrogen adsorption specific surface area are specified in the above-mentioned ranges, neutral carbon black having a strong bluish hue is selected, and a dispersion aid described later is used in combination. Thus, it is possible to obtain a penetrating dry type black ink composition for offset printing having a high density and blackness.

Furthermore, the neutral carbon black used in the present invention has a specific DBP oil absorption. The DBP oil absorption is a numerical value that affects the dispersibility of carbon black, the fluidity and blackness of the ink composition as a factor representing the size of the aggregate of carbon black. In the present invention, in particular, by setting the DBP oil absorption of neutral carbon black within the above-mentioned range, it is possible to obtain a penetrating dry type black ink composition for offset printing that minimizes the occurrence of dry-down. .

It is preferable that content of the said neutral carbon black is 10-30 mass% in the said penetrating dry type | mold ink ink for offset printing. When the content is less than 10% by mass, the blackness may be insufficient, and when it exceeds 30% by mass, printability may be deteriorated. The content of the neutral carbon black is more preferably 15 to 25% by mass in the penetrating dry ink ink for offset printing.

Next, as the rosin-modified phenolic resin and rosin-modified maleic acid resin constituting the penetrating dry ink ink composition for offset printing of the present invention, the mass average molecular weight conventionally used in offset printing inks is 10,000-20. 10,000 things can be used.
In general, when the mass average molecular weight is less than 10,000, it is difficult to obtain a sufficient viscosity as the ink composition. On the other hand, when the mass average molecular weight is more than 200,000, the fluidity of the ink composition is lowered.
The mass average molecular weight is a value in terms of polystyrene by gel permeation chromatography.

The penetrating dry ink ink composition for offset printing of the present invention may contain either one of a rosin-modified phenol resin and a rosin-modified maleic acid resin, or may be a combination of two types. .

The content of the rosin-modified phenolic resin and / or rosin-modified maleic acid resin is preferably 5 to 30% by mass in the total amount in the penetrating dry ink ink for offset printing.
When the content is less than 5% by mass, it is difficult to obtain a sufficient viscosity, and the cohesive force of the ink film is weakened and the durability may be lowered. If the content exceeds 30% by mass, the viscosity becomes too high and printing may be difficult. The content is more preferably 7 to 25% by mass.

Next, the gilsonite resin, petroleum resin, and heavy oil constituting the penetrating dry offset black ink composition of the present invention will be described.
The penetrating dry ink ink for offset printing of the present invention contains at least one selected from the group consisting of gilsonite resin, petroleum resin and heavy oil.
These gilsonite resins, petroleum resins and heavy oils are used as dispersion aids for dispersing the neutral carbon black pigment.

Examples of the gilsonite resin include gilsonite and an aliphatic hydrocarbon resin having an softening point of 120 to 125 ° C., which is an extract from gilsonite.
Gilsonite refers to asphaltite produced in Utah as defined in JIS-K 5500, is a kind of hard bitumen, and is used as a film forming element for high quality black varnish.
In the present invention, as the above-described Gilsonite, those conventionally used for black ink for offset printing can be used. For example, products commercially available from American Gilsonite, Inc. can be used.

The extract from the above-mentioned gilsonite is an alicyclic hydrocarbon resin having a softening point of 120 to 125 ° C. extracted from gilsonite, that is, natural asphaltite, and does not contain aromatic hydrocarbons, ash, and light fractions, In addition, it has excellent solubility in aliphatic ink solvents and vegetable oil components.
In the present invention, for example, Gilsonite ER-125 commercially available from American Gilsonite can be used as the extract from the above-described Gilsonite. In addition, the softening point here is a value measured according to ASTM E28-92.

The petroleum resin is a resin that uses petroleum unsaturated hydrocarbons as a direct raw material and cyclopentadiene as a main raw material, or a resin that uses higher olefinic hydrocarbons as a main raw material.
In the present invention, the petroleum resin is not particularly limited, and in addition to the petroleum resin mainly composed of the raw material, a phenol resin-modified petroleum resin obtained by phenol-modifying the petroleum resin can also be used.
Specific examples of the petroleum resin include commercially available products such as Nisseki Neopolymer Grade 120 (manufactured by Nippon Petrochemical Co., Ltd.).

As defined in JIS-M 0104, the heavy oil is a black or black-brown liquid, semi-solid or solid obtained when coal liquefied oil, petroleum, sand oil, shale oil or the like is processed. It is a high boiling mineral oil.
In the present invention, the heavy oil is not particularly limited, and heavy oil obtained by treating the above-described coal liquefied oil, petroleum, sand oil, shale oil, etc. can be used. For example, petroleum naphtha is pyrolyzed. The heavy petroleum oil obtained in this way can be used. In view of environmental considerations in recent years, it is preferable to use heavy petroleum oils that meet US OSHA standards and EU PCA standards.

Three components comprising these gilsonite resin, petroleum resin, and heavy oil are appropriately selected and used, and one component, two components, or three components are included in the penetrating dry type ink ink for offset printing.
In particular, the penetrating dry ink ink composition for offset printing of the present invention preferably contains the above gilsonite resin, and more preferably contains the above gilsonite resin and petroleum resin.

When the content of the above three components is reduced, the dispersibility of carbon black becomes insufficient. On the other hand, when the content is increased, excessive emulsification of dampening water into the resulting ink ink composition for osmotic drying offset printing occurs, and printability is improved. Tend to adversely affect Therefore, when the penetrating dry type black ink composition for offset printing of the present invention does not contain the heavy oil, the content of the gilsonite resin and / or petroleum resin is 100 parts by mass of neutral carbon black, It is preferable that it is 1-60 mass parts.

Further, when the penetrating dry offset black ink composition of the present invention contains the heavy oil, the total content of the gilsonite resin, petroleum resin and heavy oil is 100 parts by weight of neutral carbon black. On the other hand, it is preferable that it is 1-150 mass parts.
However, in this case, the upper limit of the total content of the gilsonite resin and the petroleum resin is preferably 60% by mass in the total of the gilsonite resin, the petroleum resin and the heavy oil.
The appropriate content varies depending on the type and content of the above neutral carbon black and other materials used in addition to the types of these materials, and therefore it is preferable to select an appropriate content within the above range. .

Next, the oil component constituting the black ink composition for penetrating dry offset printing of the present invention will be described.
The oil component has a function of dissolving the resin and maintaining the fluidity of the ink composition, and vegetable oil components, mineral oil components, and the like can be used.
Examples of the vegetable oil component include vegetable oil and fatty acid ester compounds derived from vegetable oil. Examples of the vegetable oil include dry oil or semi-dry oil suitable for osmotic dry offset printing such as soybean oil, cottonseed oil, linseed oil, safflower oil, tung oil, tall oil, dehydrated castor oil, and canola oil. These can be used alone or in combination of two or more.

Examples of the fatty acid ester compound derived from the vegetable oil include monoalkyl ester compounds of fatty acids derived from the drying oil or semi-drying oil. The fatty acid constituting the fatty acid monoalkyl ester compound is preferably a saturated or unsaturated fatty acid having 16 to 20 carbon atoms, and stearic acid, isostearic acid, hydroxystearic acid, oleic acid, linoleic acid, linolenic acid, and eleostearic acid. Etc. can be illustrated. The alcohol-derived alkyl group constituting the fatty acid monoalkyl ester compound is preferably an alkyl group having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, 2-ethylhexyl, and the like. It can be illustrated. The said fatty-acid monoalkyl ester compound can also be used individually, and can also be used in combination of 2 or more type.

Examples of the mineral oil component include non-aromatic petroleum solvents that are incompatible with water and have a boiling point of 160 ° C. or higher, preferably 200 ° C. or higher. Specific examples of the non-aromatic petroleum solvent include No. 0 Solvent, AF Solvent No. 5, AF Solvent No. 6, AF Solvent No. 7 (all of which are manufactured by Shin Nippon Oil Co., Ltd.).
In the penetrating dry offset ink ink composition for offset printing, the vegetable oil component and the mineral oil component used as oil components may be the vegetable oil component or the mineral oil component, respectively. You may use together with a mineral oil component.
In the penetrating dry offset ink ink composition of the present invention, the oil component is at least one selected from the group consisting of non-aromatic petroleum solvents, vegetable oils, and fatty acid ester compounds derived from vegetable oils. Is preferred.

Further, if necessary, the ink ink composition for osmotic drying type offset printing according to the present invention is a surface active agent such as a surfactant, phosphate, and waxes such as polyethylene wax, olefin wax, and Fischer-Tropsch wax. In addition, additives such as alcohols and antioxidants may be contained. Further, a gelling agent such as an aluminum chelate compound may be used to gel all or part of the binder resin.

In general, among solid and liquid components contained in a penetrating dry ink ink composition for offset printing, if the solid component is small, the ink viscosity decreases, and if the resin is further reduced as a solid component, the ink There is a tendency that the cohesive strength of the film is weakened. On the other hand, when there are too many solid components, the viscosity tends to be high and printing tends to be difficult. Therefore, the total content of the rosin-modified phenol resin, rosin-modified maleic acid resin, gilsonite resin, and petroleum resin, which are solid resin components, is suitably in the range of 10 to 60% by mass in the ink composition. is there. Moreover, it is preferable that the total content of said heavy oil which is a liquid component, and an oil component is the range of 20-80 mass% in the said ink composition.

A conventionally known method can be used to produce the penetrating dry type black ink composition for offset printing of the present invention using the above constituent materials. For example, (1) neutral carbon black, (2) rosin modified phenolic resin and / or rosin modified maleic acid resin, (3) at least one selected from the group consisting of gilsonite resin, petroleum resin and heavy oil, 4) After the oil component is kneaded and dispersed with a bead mill or a three-roll mill, the remaining components and various additives can be added and stirred as necessary.

The ink ink composition for penetrating dry offset printing of the present invention has a bluish hue and high blackness without using a special complementary colorant. Further, the dispersion stability and fluidity of the pigment are good, and after printing, This is a penetrating dry type black ink composition for offset printing having an excellent performance such that the occurrence of dry-down is small.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples without departing from the spirit and scope of application. In the following description, unless otherwise specified, “part” and “%” mean “part by mass” and “% by mass”, respectively.

<Rosin-modified phenolic resin gel varnish>
A four-necked flask equipped with a condenser, thermometer, and stirrer is combined with a rosin-modified phenolic resin (KG-1847, manufactured by Arakawa Chemical Industries) having a mass average molecular weight of 100,000, soybean oil, non-aromatic petroleum solvent (Nippon Oil) (AF Co., Ltd. AF Solvent No. 7) was charged so as to have the following blending ratio, heated to 200 ° C., and heated and dissolved at the same temperature for 1 hour. Thereafter, ethyl acetate aluminum diisopropoxide (ALCH manufactured by Kawaken Fine Chemil Co., Ltd.) was charged so as to have the following blending ratio, and heated and maintained at 170 ° C. for 60 minutes to obtain a rosin-modified phenol resin gel varnish.
(Mixing ratio)
Rosin-modified phenolic resin: 35 parts, soybean oil: 20 parts, non-aromatic petroleum solvent: 44.5 parts, ALCH: 0.5 part (total: 100 parts)

<Gilsonite resin varnish>
A four-necked flask equipped with a condenser, a thermometer and a stirrer was charged with gilsonite (Gilsonite Selects 325) and soybean oil so as to have the following blending ratio, and heated and stirred at 140 ° C. for 60 minutes to obtain a gilsonite varnish.
Gilsonite: 30 parts, soybean oil: 70 parts

<Petroleum resin varnish>
A four-necked flask equipped with a condenser, thermometer and stirrer is blended with petroleum resin (Nippon Neopolymer Grade 120, Nippon Oil Corp.) and AF Solvent No. 6 (Shin Nippon Oil Co., Ltd.) Then, the mixture was heated and stirred at 180 ° C. for 60 minutes to obtain a petroleum resin varnish.
Petroleum resin: 50 parts, AF Solvent No. 6: 50 parts

(Base ink composition for obtaining a penetrating dry ink ink composition for offset printing)
Neutral carbon black, rosin-modified phenol resin gel varnish, gilsonite resin varnish, petroleum resin varnish and heavy oil as shown in Table 1 were kneaded using a three-roll mill, Examples 1 to 8 and Comparative Examples Each base ink composition for obtaining 1 to 6 penetrating dry ink ink compositions for offset printing was obtained.

(Osmosis dry ink ink composition for offset printing)
The ink compositions for osmotic drying offset printing of Examples 1 to 8 and Comparative Examples 1 to 6 were obtained by mixing at a blending ratio such that 80 parts of each of the above base ink compositions and 20 parts of soybean oil were obtained.

<Ink evaluation>
(Density, b * value of CIE 1976 (L * a * b *) color system)
Example 1 and 0.1 cc of ink ink composition for osmotic drying type offset printing of comparative examples are developed on a sheet of paper (made by Oji Paper Co., Ltd., SL +) using a 2 split roll with an RI tester (Made Seisakusho Co., Ltd.). After that, the ink density immediately after printing and 4 hours after printing and the b * value of the CIE 1976 (L * a * b *) color system were used using a spectrophotometer / densitometer (trade name Specroye, manufactured by Gretagmacbeth). (Measurement conditions: temperature 25 ° C./humidity 50%). The measured values are shown in Table 1 as the measurement results.
Blackness: The greater the density value, the higher the blackness.
Hue: CIE 1976 (L * a * b *) is judged to be a blue hue as the b * value of the color system is smaller.

(Dry down)
Table 1 shows the difference in density immediately after printing and 4 hours after printing of the color-extracted product obtained using the ink ink compositions for osmotic drying type offset printing of Examples and Comparative Examples.
Drydown: It is judged that the occurrence of drydown is suppressed as the difference in concentration is smaller.

(Printability)
Using the ink ink composition for osmotic drying type offset printing of Examples and Comparative Examples, using a N-750 type printing laboratory machine (manufactured by Higashihama Seiki Co., Ltd.), printing speed of 120,000 copies / hour, newspaper renewal Used to print 20,000 copies of each black ink. The printing suitability was good with any penetration ink type black ink composition for offset printing.

The penetrating dry type black ink composition for offset printing of the present invention can be suitably applied to offset printing.

Claims (4)

(1) Ratio coloring power 50% to 70%, average primary particle diameter 65～100Nm, nitrogen adsorption specific surface area 20 to 40 m ² / g, and a neutral carbon black is a DBP oil absorption of 60 to 100 ^[cm 3/100 g,
(2) Rosin-modified phenolic resin and / or rosin-modified maleic resin,
(3) at least one selected from the group consisting of gilsonite resin, petroleum resin and heavy oil, and
(4) A penetrating dry type black ink composition for offset printing, comprising an oil component. (3) At least one selected from the group consisting of gilsonite resin, petroleum resin and heavy oil is heavy oil and gilsonite resin and / or petroleum resin,
The total content of the heavy oil and gilsonite resin and / or petroleum resin is 1 to 150 parts by mass with respect to 100 parts by mass of neutral carbon black. Black ink composition. (3) At least one selected from the group consisting of gilsonite resin, petroleum resin and heavy oil is gilsonite resin and / or petroleum resin,
2. The penetrating dry offset ink ink composition for offset printing according to claim 1, wherein the content of the gilsonite resin and / or petroleum resin is 1 to 60 parts by mass with respect to 100 parts by mass of the neutral carbon black. The oil component is at least one selected from the group consisting of a non-aromatic petroleum solvent, a vegetable oil, and a fatty acid ester compound derived from a vegetable oil. Ink ink composition.