JP6206722B2 - Offset ink composition and printed matter - Google Patents

Description

  The present invention relates to a osmotic drying type offset ink composition, which is excellent in emulsification stability on a high-speed offset rotary printing press, has good transferability from an ink supply roller, and also has stain resistance. It relates to an ink composition.

  In recent years, in the offset printing industry, demands for labor saving, labor saving, automation, and high-speed printing have been increasing. Printing ink is desired to obtain

  In particular, the speed of an offset rotary press that performs comics, weekly magazines, newspaper printing, etc. is increasing. In particular, in a newspaper printer, what was conventionally 500 to 600 m / min is 800 to 900 m / min, for example. The speed has increased by over 50%.

  In printing with offset water, ink is supplied from the ink source to the plate surface via a plurality of rollers, and dampening water is also supplied from the supply device to the plate surface via a plurality of rollers. Since the image area on the printing plate is oleophilic, ink is accepted, and the non-image area on the printing plate is wet, so that an image is formed on the paper surface by coating with dampening water. If the amount of ink supplied and the amount of dampening water supplied are imbalanced, printing trouble may occur. For example, if the fountain solution is insufficient in the non-image area of the printing plate, scumming occurs.

  Further, when dampening water is supplied excessively, serious printing troubles such as water rod entanglement, water eyes, density fluctuation, flying, remaining roller, and roller peeling are induced. In order to prevent these printing troubles and to reproduce an excellent printing paper surface, the emulsification state of the ink and the dampening water on the printing machine is controlled, and the water width (the dampening water is applied to the printing machine or the paper surface). It is necessary to design a prescription for printing ink that expands the range of the amount of rising water that does not cause trouble. In recent years, with the progress of high-speed printing accompanying the improvement in the performance of offset printing presses, the ratio of waste paper used for printing paper has increased, so the supply and demand balance of ink and fountain solution has changed, and an optimal and stable emulsification state It has become difficult to hold.

  In particular, in order to maintain a stable emulsified state, a phenomenon called excessive emulsification in which the ink takes up too much water must not occur. When ink that is over-emulsified is used, fountain is likely to occur because dampening water is insufficient in the non-image area of the printing plate during printing. Furthermore, if the ink is over-emulsified on the roller, the ink stickiness is lost, resulting in poor transferability between the rollers, and excess roller and flying that occurs even when dampening water is excessive. It becomes easy.

  Also, newspaper newspapers with rough surfaces and no coating treatment tend to absorb dampening water. In order to maintain a necessary amount of dampening water on the plate surface during printing, there is a tendency to increase the amount supplied from the dampening water supply device in advance. If the supply amount of dampening water on the printing plate continues to be large, the ink will take in a large amount of water on the printing plate, and will easily overemulsify.

  Two types of ink supply methods for printing using a newspaper rotary press are the mainstream at present, namely the dredge method and the digital ink pump method that supplies a fixed amount of ink to the ink source roller using a pump. Ink supply to the inker unit is also increasing in number, with a speed difference between the two rollers (delivery roller and ink base roller) of the supply unit, and a stable transfer of ink thickness of several microns. .

  In such a newspaper press, in order to stably transfer between rollers having a difference in speed, it is better that the ink is harder, more specifically, it is better to have high viscosity and low flow. On the other hand, a dampening water supply method using a spiral brush or spray dampener device is generally used, and the dampening water supply amount is larger than the continuous water supply method for commercial printing. There are many troubles regarding emulsification suitability involving water.

  In particular, newspaper inks mainly composed of vegetable oils are very difficult to impart appropriate emulsification performance to the ink because of the repulsion between water and oil in offset printing using fountain solution. If the resin selection does not compensate for the water uptake performance, excess water that could not be incorporated into the ink on the printing press will hydrophilize the printing press roller and cause roller stripping. Therefore, as a basic design of the ink, it is necessary to make the ink so that the ink can take in excess water by increasing the emulsification rate by selecting a resin or the like.

  In addition, if a highly emulsified resin is used, the ink will be excessively emulsified on the roller and the plate surface, resulting in an excessive emulsification phenomenon. Therefore, since excessive roller and flying are likely to occur, a certain amount of wet hydrophilic silica which is a kind of powdered silica having a high effect as an emulsification inhibitor is added to suppress over-emulsification.

  The types of powdered silica include dry hydrophilic silica, dry hydrophobic silica, and the like, but wet hydrophilic silica has been used as a material suitable for both fluidity suppression and emulsification suppression.

  There are two main methods for producing silica, a wet method and a dry method. The wet method is a method in which silica is precipitated by neutralization or decomposition reaction with an acid or alkali metal salt of a sodium silicate aqueous solution, and the dry method is a method in which silica is precipitated by a high-temperature gas phase reaction. is there. Silica synthesized in this way gathers silicon dioxide particles and continuously forms fine pores like a mesh, but silica synthesized by a wet method has fine pores. It is characterized in that moisture and the like are adsorbed inside, and generally has 5% or more of adsorbed moisture. On the other hand, in the dry method, the adsorbed moisture is generally 2% or less.

  Silica synthesized as described above is hydrophilic because of its structure with many hydroxyl groups on the surface, but it can also be made hydrophobic by surface treatment and substitution of hydroxyl groups with methyl groups, etc. it can. Accordingly, the wet hydrophilic silica refers to hydrophilic silica that is synthesized by a wet method and has not been subjected to surface treatment for making it hydrophobic.

  Since wet hydrophilic silica has a structure in which moisture and the like are adsorbed, there is a problem that the original emulsification inhibiting performance is not exhibited when used under high heat conditions. However, ink is always called a premix, and there is a process in which the pigment, resin, and solvent are mixed uniformly, but these are not mixed uniformly unless high heat is applied, and then coarse in a dispersion process in which the pigment is finely divided into the resin. Particles may also remain, and the coarse particles may cause troubles such as plate wear that scrapes the image area of the plate. The pigment content at this time includes not only organic pigments used in color inks and carbon black used in black inks but also inorganic pigments containing wet hydrophilic silica called extender pigments. Therefore, wet hydrophilic silica is always exposed to high heat in the conventional production method, the original emulsification suppression performance is not generated, and scumming cannot be prevented.

  Patent Documents 1 to 3 disclose offset ink compositions using powdered silica.

  In Patent Document 1, the manufacturing process conditions at the time of addition of powdered silica are limited to 90 ° C. or lower. However, in recent years, the dispersion of the 4 × 1 machine and the development-less thermal CTP plate have been increased. Since there is a tendency to emphasize the nature, it is often necessary to perform premixing at 90 ° C. or higher. In the present invention, as in Patent Document 1, the premix conditions during ink production are not limited to 90 ° C. or lower.

  In Patent Document 2, there is a description containing powdered silica, but in this document, a nonionic surfactant and a polyoxyethylene sorbitol tetrafatty acid having an HLB value of 8 to 14 is added to the ink in an amount of 0.05 to 3. On the premise that the content is 0% by weight, the purpose is to prevent the occurrence of poor inking due to plate piling, and the purpose and contents of the claims are different from the present invention.

  In Patent Document 3, there is a description containing powdered silica, but the purpose is used for fluidity and aging stability of the ink and emulsification stability during printing, which is different from the present invention. Moreover, there is no description about the dispersion of silica.

Japanese Patent Laid-Open No. 2005-248058 JP 2011-190300 A JP 2013-216735 A

  The present invention relates to an osmotic drying type offset ink composition, particularly relates to an offset ink composition excellent in stain resistance, and emulsification stability causing stains on a high-speed offset rotary printing press, It is an object of the present invention to provide a penetrating dry offset ink composition having excellent transferability from an ink supply source roller and excellent resistance to excess rollers.

  As a result of sincere research to solve the above problems, wet hydrophilic silica was not added at the time of premix (pigment dispersion), pigment (excluding wet hydrophilic silica), binder resin, vegetable oil, and petroleum-based An osmotic dry offset ink composition obtained by dispersing a mixture comprising a solvent to obtain an ink composition intermediate and then introducing a wet hydrophilic silica dispersion can solve the problems of the present invention. As a result, the present invention has been completed.

That is, in the present invention, a wet hydrophilic silica dispersion is mixed with an ink composition intermediate obtained by mixing and dispersing a pigment, a binder resin, a vegetable oil and / or vegetable oil ester, and a petroleum solvent. It relates to an ink composition for osmotic drying type offset printing, characterized by the following (1) to (3).
(1) A wet hydrophilic silica dispersion comprises wet hydrophilic silica, a binder resin,
A wet hydrophilic silica dispersion obtained by dispersing at least one compound selected from the group consisting of vegetable oils, vegetable oil esters and petroleum solvents.
(2) The wet hydrophilic silica is 10 to 40% by weight in the total amount of the wet hydrophilic silica dispersion.
(3) The wet hydrophilic silica is 0.1 to 10% by weight in the total amount of the penetrating dry offset printing ink composition.

Furthermore, this invention relates to the printed matter formed by printing the said osmosis dry type offset printing ink on a base material.

The offset ink composition provided by the present invention is an osmotic drying type offset ink used in offset rotary printing for comics, weekly magazines, newspaper printing, etc., emulsification stability on a high-speed offset rotary printing machine, ink supplier It is possible to provide an ink excellent in transferability from a roller and stain resistance.
As a result, the occurrence of stains on the print paper surface is reduced and stabilized, and the frequency of warning and paper discharge in the paper surface inspection apparatus can be drastically reduced. In addition, since the deterioration of the image area due to plate wear can be suppressed, stable paper quality can be maintained even for a long time of printing.

The osmotic dry offset printing ink composition of the present invention comprises a wet hydrophilic property in an ink composition intermediate obtained by mixing and dispersing a pigment, a binder resin, a vegetable oil and / or vegetable oil ester, and a petroleum solvent. Penetrating dry offset printing ink composition obtained by mixing a porous silica dispersion.

  Wet hydrophilic silica is not dispersed with other pigments at the same time, and the ink composition intermediate and wet hydrophilic silica dispersion are respectively created and mixed to maintain the emulsification rate suppression performance inherently possessed by wet hydrophilic silica, The printing stability is higher than before, and it is possible to solve troubles related to dirt.

  Here, the wet hydrophilic silica dispersion is a mixture of wet hydrophilic silica, a binder resin, and one or more compounds selected from the group consisting of vegetable oil, vegetable oil ester and petroleum solvent (hereinafter referred to as vegetable oil). It is necessary to be a wet hydrophilic silica dispersion (hereinafter sometimes simply referred to as a silica dispersion). The temperature during mixing and dispersion is preferably 70 ° C. or lower. If at least one of vegetable oil, vegetable oil ester and petroleum solvent is not contained, the fluidity is low and the silica dispersion cannot be suitably dispersed.

  Furthermore, it is necessary that the wet hydrophilic silica is 10 to 40% by weight in the total amount of the wet hydrophilic silica dispersion. If it is less than 10% by weight, the expected function cannot be achieved because there are few active components of silica. Further, when it exceeds 40% by weight, the dispersion is difficult and the fluidity is lost. Therefore, when added to the ink, mixing is poor and workability is deteriorated.

  Furthermore, it is necessary that wet hydrophilic silica is 0.1 to 10% by weight in the total amount of the ink composition for penetrating dry type offset printing. If the addition amount is less than 0.1% by weight, there is no effect of suppressing emulsification, and even if it is added more than 10% by weight, the optimum range for suppressing emulsification is exceeded, and problems such as roller peeling and concentration fluctuations are likely to occur. .

The wet hydrophilic silica is amorphous silica and preferably has a BET specific surface area of 20 to 400 m ² / g. If it is this range, it is suitable at the point that the dispersibility in an ink manufacture process becomes easy.
Moreover, it is preferable that adsorption | suction water | moisture content is 5% or more in the point that the emulsification suppression performance which wet hydrophilic silica originally has is exhibited. In general, silica synthesized by a wet method originally has 5% or more of adsorbed moisture.

  Examples of the binder resin include rosin-modified phenol resin, petroleum resin, alkyd resin, rosin-modified alkyd resin, petroleum resin-modified alkyd resin, and rosin ester. Preferably, a rosin modified phenolic resin is used.

  The rosin-modified phenol resin is obtained by reacting rosin with a phenol-formaldehyde initial condensate (resole resin) and then esterifying with a polyhydric alcohol. In general, rosin of rosin-modified phenolic resin includes gum rosin, wood rosin, tall rosin, polymerized rosin, disproportionated rosin, hydrogenated rosin, etc. It cannot be used because it does not react with the condensate. Polymerized rosin is a resin obtained by polymerizing rosins and has a higher softening point than rosin alone, but it is difficult to use it alone in terms of cost and performance.

  Examples of the polyhydric alcohol used in the synthesis of the rosin-modified phenol resin include divalent 1,6-hexanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, and 2,2-diethyl- 1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-cyclohexanediol, diethylene glycol and the like, and trivalent or higher glycerin, trimethylolethane, trimethylolpropane, Examples include triethylene glycol, 1,6-hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol, inositol, and cellulose. These polyhydric alcohols can be used singly or in combination in any quantity ratio. The polyhydric alcohol is preferably added in an amount of 0.5 to 1.5, more preferably 0.9 to 1.2 as an OH equivalent to the remaining carboxylic acid. The amount of polyhydric alcohol greatly affects the weight average molecular weight, viscosity, solubility in solvents / vegetable oils, and emulsification suitability of the resulting resin. When the amount of polyhydric alcohol is less than the above, the reaction rate is high. There is a possibility that the reaction will take a long time and the reaction may take a long time, and if it is large, the required performance may not be obtained.

  The temperature of the esterification reaction with the polyhydric alcohol is 180 to 280 ° C., preferably 220 to 280 ° C., more preferably 240 to 270 ° C., and the reaction is continued until the acid value reaches 15 to 30 positions. . Furthermore, it is also possible to make it react by the reduced pressure of 0-75 kPa as needed.

  In the esterification reaction, a catalyst can be used. As the catalyst, sulfonic acids such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid, methanesulfonic acid, and ethanesulfonic acid, sulfuric acid, hydrochloric acid, and the like can be used as acidic catalysts. Mineral acid, trifluoromethyl sulfate, trifluoromethyl acetic acid, Lewis acid, etc., metal complexes such as tetrabutyl zirconate and tetraisopropyl titanate, oxidation of alkali and alkaline earth metals such as magnesium oxide, calcium oxide and zinc oxide Products, metal salt catalysts and the like. These catalysts are reacted at a temperature of 200 ° C. or more at 0.01 to 1% by weight in the total resin. However, since the reactant is easily colored under such conditions, it is possible to prevent coloring by using hypophosphorous acid, triphenyl phosphite, triphenyl phosphate, etc., which are reducing agents.

  Examples of the phenol component include aromatic compounds having a phenolic hydroxyl group such as phenol, p-cresol, p-tertiary butylphenol, p-amylphenol, p-octylphenol, p-nonylphenol, p-dodecylphenol, and bisphenol A. .

  As the formaldehyde component, formalin, paraformaldehyde and the like can be used. Addition-condensation reaction of 0.5 to 3.0 moles of aldehyde component is performed by a conventional method with respect to 1 mole of phenol component.

  The phenol-formaldehyde initial condensate is a resol type phenol resin, and the phenol component and the formaldehyde component are 5 to 100 parts by weight, preferably 10 to 50 parts by weight of toluene or xylene with respect to 100 parts by weight of the total quantity. It can be obtained by adding a volatile organic solvent such as and condensing reaction in an alkali catalyst. Examples of the alkali catalyst include potassium hydroxide, sodium hydroxide, calcium hydroxide, magnesium hydroxide and the like.

  In the present invention, rosin-modified maleic acid resin, rosin-modified alkyd resin, polyester resin, petroleum resin, and the like may be added to the rosin-modified phenol resin as necessary. They can be used alone or in combination of two or more.

  The binder resin used in the present invention desirably has an oxidation of 5 to 30 (mgKOH / g), preferably 5 to 25 (mgKOH / g), more preferably 5 to 20 (mgKOH / g). If the oxidation of the binder resin is less than 5 (mgKOH / g), the polarity of the resin is low, and it does not react with a gelling agent such as aluminum chelate at the time of gel varnish preparation. Affects print quality such as deterioration. Moreover, the emulsification suitability with dampening water is inferior, and the printability is affected. If the oxidation of the binder resin is greater than 30 (mgKOH / g), the compatibility with petroleum-based solvents and vegetable oils will be poor, the fluidity and stability over time of the ink will be poor, and the polarity will be high. It causes trouble.

  The binder resin used in the present invention desirably has a softening point of 120 to 300 ° C., preferably 140 to 270 ° C., more preferably 150 to 240 ° C. by the ring and ball method. When the softening point of the binder resin is less than 120 ° C., the set-off suitability is remarkably inferior and is not practical. When the softening point is higher than 300 ° C., the fluidity of the ink is impaired and the printability and transferability are remarkably deteriorated.

In the present invention, the binder resin is preferably a rosin-modified phenol resin having a weight average molecular weight of 10,000 to 200,000 and a tolerance of 22 to 49% by weight, and further a weight average molecular weight of 20,000 to 80,000 and a tolerance of 22 to 30% by weight. A rosin modified phenolic resin is preferred.
When the weight average molecular weight is 10,000 or more, the viscoelasticity of the ink is improved, and when it is 20000 or less, the fluidity and gloss of the ink are improved. Further, when the tolerance is 20% by weight or more, the ink setting property is improved, and the set-off stain and the misting performance can be prevented from being deteriorated. When the tolerance is 50% by weight or less, solvent detachment on the printing press can be prevented, so that deterioration in printability due to increase in viscosity of ink, decrease in fluidity, and increase in tack can be suppressed, and gloss is further improved.

  The tolerance in the present invention means that 2.50 g of resin and 5 g of AF Solvent No. 5 (manufactured by JX Nippon Mining & Energy Co., Ltd., aniline point 88 ° C., boiling point 288 ° C.) are placed in a test tube in 5 minutes while stirring appropriately The temperature is raised to 180 ° C., the dissolved material is cooled to 25.0 ° C., and diluted with No. 0 Solvent M (manufactured by JX Nippon Oil & Energy Corporation) little by little while stirring. The tolerance value is obtained from the amount of the No. 0 solvent M obtained by the following equation.

  In the present invention, the vegetable oil refers to a vegetable oil ester which is a vegetable oil and / or a compound derived from a vegetable oil. The vegetable oil is a triglyceride of glycerin and an unsaturated fatty acid having at least one carbon chain double bond or triple bond, and a regenerated vegetable oil is also included therein. The vegetable oil ester is a compound derived from vegetable oil containing a fatty acid monoester obtained by subjecting a triglyceride to a saturated or unsaturated alcohol, or a fatty acid monoester obtained by directly esterifying a fatty acid of a vegetable oil and a monoalcohol.

  Representative examples of the above-mentioned vegetable oils are: Asa seed oil, flaxseed oil, eno oil, psyllium oil, olive oil, cacao oil, kapok oil, kaya oil, mustard oil, kyounin oil, kiri oil, kukui oil, walnut oil, poppy Oil, sesame oil, safflower oil, 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, Pine seed oil, cottonseed oil, coconut oil, peanut oil, dehydrated castor oil, and the like, as well as thermal polymerized oil and oxygen-blown polymerized oil thereof can be used. Moreover, in this invention, these vegetable oils may be used independently and can also be used in combination of 2 or more type.

  The vegetable oil preferably has an iodine value of 80 to 130 (mg / 100 mg), and more preferably has an iodine value of 90 to 110 (mg / 100 mg). When the iodine value is higher than 130 (mg / 100 mg), the viscosity of the ink in the storage container and the fluidity are liable to be deteriorated.

  Typical examples of monoalcohols used in the production of vegetable oil esters are methanol, ethanol, n- or iso-propanol, n, sec or tet-butanol, heptynol, 2-ethylhexanol, hexanol, octanol, decanol, Examples thereof include saturated alcohols such as dodecanol, unsaturated aliphatic alcohols such as oleyl alcohol, dodecenol, husetelli alcohol, somaryl alcohol, gadrelyl alcohol, 11-icosenol, 11-docosenol, and 15-tetracosenol.

  The vegetable oil ester can be used in combination with a vegetable oil containing a regenerated vegetable oil and used in an amount of 1 to 20% by weight based on the total weight of the ink. In this case, when the vegetable oil ester exceeds 20% by weight with respect to the total weight of the ink, the printability deteriorates due to the viscosity of the ink being lowered.

  The vegetable oils mentioned above can be used as the vegetable oil in the present invention, and the content of the vegetable oil is 1 to 60% by weight based on the total amount of the printing ink composition.

In the present invention, the petroleum-based solvent is a crude oil-derived solvent having an aromatic hydrocarbon content of 1% by weight or less, and has a boiling point of 260 to 350 ° C., preferably 280 to 340 ° C. Is preferred. When the boiling point of petroleum-based solvent is 260 ° C or higher, solvent evaporation of the ink on the printing press is suppressed and the fluidity of the ink is improved, so that the ink can be transferred to a roller, blanket, plate, etc. Turn into. Moreover, when the boiling point of the petroleum solvent used in combination is 350 ° C. or less, it is suitable for the drying property of the ink. Further, an aniline point of 75 ° C. to 95 ° C. is suitable for the petroleum solvent. When the aniline point is 75 ° C to 95 ° C, the ability to dissolve the resin is suitable, and the ink viscosity and fluidity can be suitably maintained. For this reason, it becomes possible to suppress scumming resistance and ink accumulation on rollers, plates, and blankets. Such non-aromatic petroleum solvents include AF5 and AF6 manufactured by Nippon Oil Corporation.

  Moreover, arbitrary inorganic and organic pigments can be used as the pigment used in the present invention. Examples of inorganic pigments include yellow lead, 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, C.I.). CI Pigment Violet 19), dioxazine pigments (CI Pigment Violet 23), and the like. Not intended to be.

  In addition, the offset ink composition of the present invention can use various additives for the purpose of anti-friction, anti-blocking, slip and anti-scratch as other additives, and leveling agents and antistatic agents as necessary. An agent, a surfactant, an antifoaming agent, etc. may be added.

  Examples of the base material used in the present invention include not only newspaper renewal paper but also general printing paper such as coated paper and non-coated paper.

  The acid value (mgKOH / g) in the present invention was measured according to JIS K-5701.

  The measurement of the softening point by the ring-and-ball method is a method widely used in the standard test method, and JIS K 2046 can be mentioned. Specifically, a brass ring filled with a sample is held horizontally in a water bath, a steel ball of a constant weight is placed on the center of the sample, the bath temperature is increased at a constant speed, the sample gradually softens, and the steel ball is The softening point is determined by the reading of the thermometer when it descends and finally reaches the bottom plate at a thickness of 25 mm.

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. The eluent is tetrahydrofuran, and the column is TSKgel SuperHM-M (Tosoh Corporation).
Three) were used. 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.

  The aniline point (° C) of the petroleum solvent in the present invention is the lowest temperature at which an equal volume of aniline and the sample exist as a homogeneous solution (from the state where the aniline and the sample are completely dissolved, Is a temperature at which turbidity occurs and the turbidity occurs), and is performed in accordance with JIS K-2256. The boiling point of the petroleum solvent is measured according to JIS K-2254, and the boiling point refers to the temperature at which 50% of the solvent is distilled when distilled.

  The present invention will be described in more detail with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the present invention, “part” represents “part by weight” and “%” represents “% by weight”.

(Phenolic resin production example)
To a four-necked flask equipped with a stirrer, a cooler, and a thermometer, add 1000 parts of p-octylphenol, 850 parts of 35% formalin, 60 parts of 93% sodium hydroxide, and 1000 parts of xylene, and react at 95 ° C. for 4 hours. . Thereafter, 125 parts of 6N hydrochloric acid and 1000 parts of tap water were added, stirred and allowed to stand, and the upper layer was taken out to obtain 2000 parts of a xylene solution of a resole-type phenol resin having a nonvolatile content of 51%. Y.

(Production example of rosin-modified phenolic resin (resin A))
A four-necked flask equipped with a stirrer, a condenser with a water separator, and a thermometer was charged with 1500 parts of gum rosin (Arakawa Chemical "Chinese Rosin X") and dissolved at 200 ° C while blowing nitrogen gas. 1600 parts of Y was added and reacted at 230 ° C. for 4 hours while removing xylene. Then, 115 parts of glycerin was added and reacted for 4 hours, and 75 parts of maleic anhydride was added and esterified at 250 to 260 ° C. A rosin-modified phenolic resin A (hereinafter referred to as “resin A”) having a molecular weight of 12500, an acid value of 20, a softening point of 155 ° C., and a cloud point of 80 ° C. was obtained.

(Rosin modified phenolic resin varnish (varnish B) production example)
In a four-necked flask with a stirrer, a water-cooling reflux condenser, and a thermometer, the resin A45 parts, soybean oil 39 parts, soybean oil fatty acid normal butyl ester 15 parts, ALCH (manufactured by Kawaken Fine Chemical Co., Ltd.) 1 part of an agent) was added and heated and stirred at 190 ° C. for 1 hour to obtain a rosin-modified phenolic resin varnish B (hereinafter referred to as “varnish B”).

(Manufacture of gilsonite resin varnish)
A four-necked flask equipped with a condenser, a thermometer, and a stirrer was charged with 40.0 parts of ER-125 (manufactured by Arizona Chemical Co.) and 60.0 parts of soybean oil, and the temperature was raised to 140 ° C. The mixture was stirred for a minute to obtain a gilsonite resin varnish.

(Wet hydrophilic silica dispersion production example 1)
15 parts wet wet silica "Nipseal LP" (manufactured by Tosoh Silica), 70 parts varnish B, 15 parts soybean oil at 70 ° C or lower using a high speed mixer, and then roll temperature of 60 ° C Dispersion was carried out with this roll (the particle diameter was measured with a grindometer, and the number of generated lines was 7.5 μm or less, 3 or less) to obtain a wet hydrophilic silica dispersion (hereinafter referred to as silica dispersion C1). .

(Wet hydrophilic silica dispersion production example 2)
40 parts wet hydrophilic silica “Nipseal LP” (manufactured by Tosoh Silica), 45 parts varnish B, 13 parts soybean oil and 2 parts vegetable oil ester at 70 ° C. or lower using a high speed mixer, and then roll temperature Is dispersed with three rolls at 60 ° C. (particle diameter is measured with a grindometer, and the number of generated lines is 3 or less at 7.5 μm) and wet hydrophilic silica dispersion (hereinafter referred to as silica dispersion C2 and Obtained).

  The obtained varnish B was dispersed using a three-roll roll with the composition shown in Table 1 below (excluding Dispersion C and the adjustment solvent), and then the obtained Dispersion C was added and stirred using a high speed mixer. It adjusted so that it might become 9.5-10.5 Pa.s by a L-type viscosity meter viscosity, and Examples 1-6 of the osmosis dry type offset ink composition were obtained. The temperature during premixing was 100 ° C., and the roll temperature during the dispersion of the three rolls was all 60 ° C. The temperature of the base ink when the dispersion C is charged is 70 ° C. or less, and the temperature of the compound is 25 ° C. at room temperature.

AF Solvent No. 6 in Table 1 below is a solvent with an aniline point of 94 ° C. and a boiling point of 309 ° C. manufactured by Shin Nippon Oil Co., Ltd., and is used as an adjustment solvent for adjusting to a predetermined viscosity.

The organic bentonite in Table 1 below is a substance mainly composed of a mineral called montmorillonite, and also having quartz, mica, feldspar, zeolite and the like as accessory components, and is added to suppress fluidity.

  Similarly, after dispersing with three rolls with the composition shown in Table 2 below, the mixture was stirred using a high speed mixer, adjusted to L-type viscometer viscosity of 9.5 to 10.5 Pa · s, and osmotic dried. Comparative Examples 1 to 4 of the mold offset ink composition were obtained. The premix temperature was 100 ° C. and 70 ° C., and the roll temperatures when the three rolls were dispersed were all 60 ° C.

<Performance evaluation test 1 Kneading degree>
After stirring for 10 minutes with a high speed mixer in the formulation of the above examples and comparative examples, using a CH-9240 Uzwill hydraulic three roll mill manufactured by BUHLER, dispersion was performed under the conditions of 60 ° C. and 9 bar, and the particle size at that time Were measured with a grindometer, and the particle sizes at which the number of lines generated at that time was 3 were compared. The smaller the particle size, the easier it is to disperse.
(Evaluation criteria)
○: Particle diameter 7.5 μ or less Δ: Particle diameter 10.0 μ or less ×: Particle diameter 10.0 μ or more The practical level is “◯”.

<Performance evaluation test 2 Ink fluidity>
Measure a certain amount of test ink in an ink pipette, drop it onto a horizontal glass plate, and immediately stand vertically. Thereafter, the length of the ink flowing in 10 minutes is measured. The smaller the value, the more effective the fluidity suppression, and the higher the drooping, concentration fluctuation, and natural ejection suppression effect from the rail.
(Evaluation criteria)
○: 70 mm or less Δ: 70 mm or more, less than 120 mm x: 120 mm or more The practical level is “◯”.

<Performance evaluation test 3 Emulsification rate>
While stirring 10 g of ink with a disper, 10 g of distilled water is gradually added and forcedly emulsified at 1200 rpm for 3 minutes. Then, excess water was scraped off on the copper plate using a knife spatula, the emulsification rate was measured with a Karl Fischer moisture system, and evaluation was performed based on the following evaluation criteria.
(Evaluation criteria)
○: 5% or more, less than 15% Δ: 15 or more, less than 20% ×: 20% or more

<Performance evaluation test 4 Ink transferability>
Evaluation was carried out by actually printing on a 2N-750 type printing machine from Higashihama Seiki Co., Ltd. 10 points from the spray dampener value that eliminates background smudges with normal pattern and density, print continuously 3000 copies, then increase 10 points and print 3000 copies, and the following evaluation from the change in density at that time Evaluation was performed based on criteria.
(Evaluation criteria)
○: The average density change is ± 0.05 or less when the spray dampener rises 10 points, ± 0.1 or less when the spray dampener rises 20 points Δ: The average density change is ± 0.11 or less when the spray dampener rises 10 points , 20 points increase ± 0.2 or less ×: The average density change is ± 0.21 or less when spray dampener 10 points increase, 20
± 0.3 or less with point increase

<Performance Evaluation Test 5 Dirt>
Evaluation was carried out by actually printing on a 2N-750 type printing machine from Higashihama Seiki Co., Ltd. The density is adjusted with a spray dampener value of 20 for a general pattern, the dampener value is lowered by 5 points for every 500 copies, the dampener value minus 10 continuously until 3000 copies are printed, the machine is stopped, and the dampener value where the paper starts to become dirty Was visually evaluated.
(Evaluation criteria)
○: Dirt is not seen when the spray dampener value is minus 10. Δ: Dirt is seen when the spray dampener value is 0 to minus 10. X: Dirt is seen when the spray dampener value is 0 to 15. (Printing conditions)
Printing machine: Higashihama Seiki Co., Ltd. 2N-750 printing machine (dampening water supply mechanism: spray supply system)
Plate: CTP plate for flat plate HN-N (Fuji Film Co., Ltd.)
Paper: Oji Paper Co., Ltd. SL paper Printing speed: 120,000 copies / hour Dampening water: Toyo Ink Co., Ltd. NEWSKING ALKY (dampening water concentration 0.5% by volume)

<Performance Evaluation Test 6 Plate Wear>
Evaluation was carried out by actually printing on a 2N-750 type printing machine from Higashihama Seiki Co., Ltd. After performing density adjustment with a spray dampener value of 20 using a general pattern, after continuously printing 50000 copies, the state of plate wear between the plate surface and the paper surface was confirmed and visually evaluated.
(Evaluation criteria)
○: There is no trend on both the plate and paper.
Δ: A trend was observed on the plate surface, but no trend was observed on the paper surface.
X: A tendency was observed on both the plate and paper.
(Printing conditions)
Printing machine: Higashihama Seiki Co., Ltd. 2N-750 printing machine (dampening water supply mechanism: spray supply system)
Plate: CTP plate for flat plate HN-N (Fuji Film Co., Ltd.)
Paper: Oji Paper Co., Ltd. SL paper Printing speed: 120,000 copies / hour Dampening water: Toyo Ink Co., Ltd. NEWSKING ALKY (dampening water concentration 0.5% by volume)

The performance evaluation test results are shown in Table 3.

  From the results in Table 3, it was found that the examples were excellent in kneadability, fluidity, emulsification rate, ink transferability, stain, and plate wear resistance, and excellent in all.

 Through the above-described embodiments of the present invention, it is possible to optimally suppress the emulsification of the ink, so that it is excellent in background stain resistance in a high-speed offset rotary printing press, and has improved kneadability and excellent plate wear resistance compared to the prior art. It has been found that a mold offset ink composition is provided.

Claims (2)

Osmotic dry offset printing in which a wet hydrophilic silica dispersion is mixed with an ink composition intermediate obtained by mixing and dispersing a pigment, a binder resin, a vegetable oil and / or vegetable oil ester, and a petroleum solvent. An ink composition for osmotic drying offset printing, characterized by the following (1) to (3).
(1) A wet hydrophilic silica dispersion comprises wet hydrophilic silica, a binder resin,
A wet hydrophilic silica dispersion obtained by dispersing at least one compound selected from the group consisting of vegetable oils, vegetable oil esters and petroleum solvents.
(2) The wet hydrophilic silica is 10 to 40% by weight in the total amount of the wet hydrophilic silica dispersion.
(3) The wet hydrophilic silica is 0.1 to 10% by weight in the total amount of the penetrating dry offset printing ink composition. A printed matter obtained by printing on a base material the ink for penetrating dry offset printing according to claim 1 .