JP6056922B2 - Offset printing ink composition and printed matter - Google Patents

Description

  The present invention relates to an oxidation polymerization type offset printing ink composition containing amorphous silica, binder resin, vegetable oil, petroleum solvent and pigment, and a printing method using the same, and more particularly, emulsification appropriateness at the time of printing The present invention relates to an oxidation polymerization type offset printing ink composition and a printed matter excellent in emulsion stability.

  In recent years, in the offset printing industry, demands for labor saving, labor saving, automation, and high-speed printing have been increasing. Is desired.

Oxidation polymerization offset printing is a printing method in which vegetable oil is oxidized and solidified by oxygen in the air and dried after printing on paper. In recent years, in the offset printing industry, interest in environmental considerations in printed materials and printing work sites has been increasing year by year, and ink having high environmental performance has been demanded. For example, in the long history of offset printing, petroleum-based solvents, which are volatile organic solvents that have been used in the past, have become aromatic-free solvents with an aromatic content of less than 1%. 1% by weight of volatile organic compounds discharged from ink without any volatile petroleum solvent that protects the solvent and further protects the environment
There is an increasing need for VOC-free inks (Non-VOC inks) that are suppressed to the following.

In recent years, the concept of carbon offset, which reduces emissions of greenhouse gases such as CO _2, which cannot be avoided in daily life and economic activities due to global warming issues, has become widespread. Demand is increasing.

  VOC (Volatile Organic Compound) is a compound that easily volatilizes at room temperature, and the US Environmental Protection Agency presents the measurement of residual heating by heating at 110 ° C. for 1 hour as a VOC measurement method. It is used as an appropriate measurement method.

  However, replacing the oil-based solvent component with vegetable oils while maintaining the conventional resin for offset printing inks that uses a petroleum-based solvent component significantly reduces the ink setting and drying properties and comes out of the printing press. When the printed material is stacked, the printed surface adheres to the back of the paper, and when the dried printed material is stored at high temperature and high humidity, the printed surface re-softens and causes a blocking phenomenon that adheres to the other surface. .

  In order to prevent these problems, a method of maintaining the balance between setting property, drying property and blocking property by significantly reducing the solubility of the resin used or significantly improving the softening point is employed. Since the fluidity is impaired and the transferability of the ink is deteriorated, the printability is remarkably deteriorated, and the gloss value of the printed surface cannot be sufficiently obtained.

  In addition to non-VOC inks, the molecular weight and solubility balance of resins used have been reviewed for general oxidation polymerization type inks as printing presses have become faster and shorter in recent years. Changing the resin physical properties has a great influence on the emulsification suitability of the ink.

In printing with offset water, ink is supplied from the ink fountain to the plate surface via a plurality of rollers, and dampening water is supplied from the water boat to the plate surface via a plurality of rollers. Since the image area on the printing plate is oleophilic, ink is accepted, and since the non-image area on the printing plate is hydrophilic, 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 dampening water is insufficient in the non-image area of the printing plate, a piling phenomenon generally referred to as a non-image area residue and background stains occur.
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 is difficult to hold.

In particular, oxidative polymerization type inks and non-VOC inks mainly composed of vegetable oils are poor in emulsification of the ink because of the repulsion between water and oil in offset printing using fountain solution. Excess water that can not be taken in causes the roller of the printing press to become hydrophilic, causing roller stripping, or over emulsification and poor transferability, and ink remaining on the roller is stained outside the paper width or dirty on the water source roller There is also a problem that it is easy to cause.

  In recent years, the amount of water that can be taken into the tank by improving the emulsification rate of the ink by improving the resin surface and additives in order to reduce excess surface water that can no longer be taken into the ink for the purpose of improving roller stripping. In some cases, simply increasing the emulsification rate of the ink may cause a residual ink on the roller due to a deterioration in the transferability of the emulsified ink, and eventually cause a phenomenon of inducing roller stripping. ing. The emulsified ink is transferred to the paper through the plate and the blanket, but the excessively emulsified ink causes unevenness in the inking on the paper surface and the quality of the halftone dot is remarkably inferior.

  Conventionally, as a method for adjusting the emulsification suitability of an ink, a method of adding an auxiliary agent such as an alcohol or a surfactant into the ink has been employed.

  Patent Documents 1 and 2 disclose a technique for improving emulsification suitability by adding 0.1 to 5% by weight of a diol during the ink composition, and improving troubles on the printing press and background stains. The alcohol-based additive amplifies the ink viscoelasticity after emulsification, and is therefore an effective means for an offset rotary printing press that performs printing in an ultra-high speed region. However, general oxidation polymerization type ink is mainly used. In a sheet-fed printing press, an increase in ink viscoelasticity may cause poor transfer of ink between rollers and poor gloss due to deterioration in leveling after printing, which is not an effective means.

  Patent Document 3 discloses a method in which 0.01 to 10% by weight of dimer diol is added to the ink composition. However, since the balance of emulsification is changed by the shear stress applied to the ink, the speed has been increased in recent years. It is not possible to fully support the printed printing method.

  Patent Documents 4 to 6 disclose a method for improving emulsification suitability by adding a surfactant. Generally, cationic surfactants, anionic surfactants, amphoteric surfactants having a low surface tension, When a nonionic surfactant is used, the surface tension of the ink is remarkably lowered, and the ink is easily dispersed in the fountain solution. Therefore, troubles such as scattering stains and metering tangles are likely to occur. Also, if ink using a surfactant is left on the ink fountain for a long time, the fluidity tends to be lost, and if a certain external force is not applied, the fluidity is not recovered, and there is a problem commonly referred to as wrinkle escape. Be triggered.

  In addition, auxiliary agents such as alcohols and surfactants having a low boiling point are discharged in the atmosphere as VOC components, so that they cannot be used for non-VOC inks.

  Patent Document 7 discloses an osmotic drying type lithographic printing ink characterized by containing powdered silica, but its contents are not specific and practical examples are not found because of lack of examples.

  Patent Document 8 discloses a heat-set overprint varnish composition containing silica, a highly reactive metal organic compound, a binder resin, a vegetable oil, and a petroleum solvent. The present invention provides an overprint varnish excellent in mat effect, friction resistance, and emulsification fluidity in combination with the highly reactive organic compound, and has a different object from the present invention.

JP 2000-290576 A JP 2001-247803 A JP 09-25443 A JP 2007-31477 A JP 2007-169465 A JP 2010-229299 A Japanese Patent Laid-Open No. 2005-248058 JP 2010-229302 A

  An object of the present invention is to provide an oxidation polymerization type offset printing ink composition and a printed matter excellent in ink fluidity and emulsion stability during printing.

  As a result of sincere research to solve the above problems, it is an oxidation polymerization type offset printing ink composition containing a binder resin, a vegetable oil, a petroleum solvent and a pigment, and containing a specific amorphous silica. The offset printing ink composition is excellent in ink fluidity, stability over time and emulsification stability during printing, and can provide stable printed matter with less density fluctuations by preventing excessive emulsification and excess ink on the roller. The inventor has completed the present invention.

That is, the present invention is an oxidation polymerization type offset printing ink composition containing amorphous silica, a binder resin, a vegetable oil, a petroleum solvent and a pigment,
Amorphous silica
Average secondary particle size 0.05 to 10 μm
And a BET specific surface area of 20 to 400 m ² / g
And
0.1 to 10% by weight based on the total weight of the ink
The present invention relates to an oxidation polymerization type offset ink composition characterized by being contained.

  The present invention also relates to the above oxidation polymerization type offset ink composition, wherein the amorphous silica is a synthetic amorphous silica produced by a wet method or a dry method.

Furthermore, the present invention provides the binder resin,
Acid value 5-30 (mgKOH / g),
Softening point 120-300 ° C by ring and ball method
And a weight average molecular weight of 10,000 to 100,000
It is related with said oxidation polymerization type offset ink composition characterized by the above-mentioned.

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

  The oxidation polymerization offset ink composition provided by the present invention is an alcohol that has been used in the printing of books, books, leaflets, catalogs, etc., and has excellent fluidity and temporal stability of ink and emulsion stability during printing. Without using a system or surfactant-based additive, it is possible to prevent over-emulsification and residual ink on the roller, and provide a stable printed matter with little variation in density. Excess dampening water causes deterioration of the halftone dot shape of the printed matter and poor drying of the oxidation polymerization type ink. However, the oxidation polymerization type offset ink composition provided by the present invention is excessive by increasing the insensitivity of the ink. Even if no dampening water is supplied, printed matter can be prevented from being smudged.

  The present invention can be applied to an environment-friendly Non-VOC ink that does not use a volatile organic solvent, and can provide a printing environment and printed matter that are more environmentally friendly.

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

Silica is a general term for silicon dioxide (SiO ₂ ) or substances composed of silicon dioxide, and can be broadly divided into two categories: natural products and synthetic products. Furthermore, natural products and synthetic products are further classified into two types, crystalline and amorphous, and there are many types and they are used in various fields.

  Silica takes various forms (crystal polymorphs) depending on conditions such as pressure and temperature. Examples of the natural crystalline silica include quartz, quartz, and silica sand, and examples of the amorphous silica include diatomaceous earth and activated clay. Examples of the synthetic amorphous silica include dry silica, wet silica, silica gel and the like.

  Synthetic amorphous silica is divided into dry silica and wet silica depending on the production method. Dry process silica is produced by burning silicon tetrachloride gas in the gas phase, and wet process silica is produced by neutralization or decomposition reaction of sodium silicate aqueous solution with acid or alkali metal salt. Called.

  Moreover, in the wet method silica, precipitation method silica, gel method silica, etc. are mentioned from the difference in a production | generation process.

  Precipitated silica is characterized by a neutralization reaction between sodium silicate and mineral acid in a relatively high temperature and alkaline pH range, and the silica primary particles grow rapidly, and the primary particles are agglomerated in the form of flocs and settled. It is a method to make it. In recent years, a synthesis method has been adopted in which primary particles are grown in the aggregated state after causing aggregation while suppressing the growth of primary particles under conditions such as neutral pH range, low temperature, and high salt concentration. ing.

  Gel silica is characterized by a neutralization reaction between sodium silicate and mineral acid in an acidic pH region, and causes aggregation in a state where growth of primary particles is suppressed. At this time, since the whole reaction liquid becomes a lump gel by the tertiary network structure formed by the aggregates, it is called gel method silica.

The wet process silica surface has more silanol groups than the dry process silica surface and has a certain hydrophilicity. There are also hydrophobic silicas whose surface silanol groups are surface-treated with silanes such as polydimethylsiloxane, methylchlorosilane, hexamethyldisilazane, and silicones.
The synthetic amorphous silica used in the present invention may be produced by any of a dry process and a wet process as long as the physical property range of claim 1 is satisfied.

  Synthetic amorphous silica forms primary particle aggregates (secondary particle structure) by fusing or chemically bonding the primary particles of 5 to 55 nm, which is the minimum constituent unit of the substance. In addition, primary particle aggregates physically aggregate and exist as secondary aggregates, but secondary aggregates give primary particle aggregates (secondary particle structure) by applying physical shearing force in various media. Can be dispersed. The average secondary particle system of the present invention refers to a primary particle aggregate (secondary particle structure).

  The silica in the present invention has an average secondary particle diameter of 0.05 to 10 μm, preferably 0.1 to 7.5 μm, more preferably 0.2 to 5 μm, and further preferably 0.3 to 3 μm. . When the average secondary particle diameter is less than 0.05 μm, it is composed of strong bonds of primary particles having a smaller particle diameter, so that the particles are hard and plate wear tends to occur. In addition, since the specific surface area becomes large, it has high oil absorption performance, and sufficient fluidity cannot be obtained when it is inked. On the other hand, if the average secondary particle diameter is larger than 10 μm, it will lead to piling during printing, poor transfer between rollers, and poor ink deposition.

  The amorphous silica content in the present invention is 0.1 to 10% by weight, preferably 0.3 to 7% by weight, more preferably 0.5 to 5% by weight, and still more preferably 0.8 to 3% by weight is desirable. If the silica content is less than 0.1% by weight, no effect is seen in emulsification stability and emulsification fluidity during printing, and if it is more than 10% by weight, the fluidity and transferability of the ink are impaired.

The silica in the present invention has a BET specific surface area of 20 to 400 m ² / g, preferably 50 to 300 m ² / g, and more preferably 80 to 250 m ² / g. When the BET specific surface area is less than 20 m ² / g, it is difficult to obtain viscoelasticity necessary for the oxidation polymerization type offset ink, and there is a concern that problems such as piling are likely to occur due to the relatively large particle size. On the other hand, if the BET specific surface area is larger than 400 m ² / g, the cohesive force between the primary particles of silica becomes too strong, and the load in the dispersion process increases, resulting in poor dispersion, poor fluidity, deterioration of plate wear, etc. Problems arise.

  The average particle diameter of the fine particle aggregate in the present invention can be determined by measurement by a general laser diffraction method, scattering method, etc., and the average value of the diameter when assuming a circle equal to the projected area of the fine particle aggregate Is the average particle size.

  Moreover, the BET specific surface area in this invention is a specific surface area value which measured the amount of monomolecular adsorption | suction according to BET type | formula (Brunauer, Emmand Teller's equation).

  Examples of the binder resin used in the present invention 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 phenolic resin of the present invention 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.

  Gum rosin collects raw pine oil that is damaged by pine tree trunks, collects it, removes impurities by filtration, and then distills it to separate low-boiling turpentine oil (a liquid substance having aromaticity at room temperature). Is obtained.

  Wood rosin is a component obtained after digging up a stump after cutting a pine tree, extracting the chips into a chip, and separating the solvent and the low-boiling component turpentine oil.

  Tall rosin is a kraft method in which chemicals are added to wood chips and decomposed under high temperature and pressure to remove pulp fibers.When pine is used as wood, the resin component is crude tall oil. This rosin is recovered as a by-product called tal oil, which means pine oil, and is obtained by precision distillation of this crude tall oil.

  Examples of the polyhydric alcohol include divalent 1,6-hexanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-cyclohexanediol, diethylene glycol, etc. are also trivalent or higher glycerin, trimethylolethane, trimethylolpropane, triethylene glycol, 1,6-hexane Examples include diol, 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 reaction product 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 thereof include aromatic compounds having a phenolic hydroxyl group such as phenol, p-cresol, p-tertiary butylphenol, p-amylphenol, p-octylphenol, p-nonylphenol, p-dodecylphenol, bisphenol A and the like.

  In phenols having an alkyl group of C4 or lower, the softening point of the resin is increased and the solubility is remarkably inferior. In addition, phenols having an alkyl group of C9 or higher cause the resin solubility to be too good, resulting in deterioration of setting properties and blocking properties.

  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.

  Furthermore, it is also possible to use a rosin-modified phenolic resin modified with an α, β-ethylenically unsaturated dibasic acid as the third component. The α, β-ethylenically unsaturated dibasic acid may be an anhydride, fumaric acid, maleic acid, maleic anhydride, succinic acid, succinic anhydride, adipic acid, sebacic acid, azelaic acid, itaconic acid, anhydrous Itaconic acid, phthalic anhydride, isophthalic acid, terephthalic acid, trimellitic anhydride, pyromellitic acid, dimer acid, trimer acid and the like can be mentioned. Particularly preferred is maleic acid or its anhydride. These dibasic acids can be modified as previously a) reacted with rosin, b) reacted with rosin ester, c) incorporated in other synthetic reaction processes.

  The reaction between the resin acid and the α, β-ethylenically unsaturated dibasic acid or its anhydride is a Diels Alder or polymerization reaction, and can be performed by a known method. For example, the Diels-Alder reaction temperature is 120 to 300 ° C, preferably 180 to 260 ° C, and the reaction time is 1 to 4 hours.

  The α, β-ethylenically unsaturated dibasic acid is added in an amount of 0.1 to 10% by weight, preferably 0.1 to 5% by weight, based on rosin. The amount of α, β-ethylenically unsaturated dibasic acid added greatly affects the viscosity of the resulting resin, solubility in solvents / vegetable oils, and emulsification suitability, and is less than 0.1% by weight based on rosin. , Sufficient resin viscosity and emulsification stability when converted to ink cannot be obtained, and if it is 10% by weight or more, the solubility is remarkably inferior, the emulsification rate is extremely increased due to the increase in polar groups, and trouble due to over-emulsification Invite.

  The rosin-modified phenol resin used as the binder resin of the present invention is not particularly limited, and a conventionally known method for producing a rosin-modified phenol resin can be used. Specifically, in the phenol-formaldehyde addition condensate, the above phenols and aldehydes are charged into a reaction kettle at a predetermined ratio, and a solvent such as toluene and xylene is added so that the solid content of the phenol resin becomes 40 to 70% by weight. Add, continue reaction at 80-120 ° C for 3-8 hours using a known alkali catalyst such as sodium hydroxide, potassium hydroxide, calcium hydroxide, tertiary amines, etc., then cool to separate and remove water Can be obtained.

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

The binder resin used in the present invention has an acid value 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 printed matter is stacked with the softening point of the binder resin being less than 120 ° C., blocking tends to occur, which is not practical. When the softening point is higher than 300 ° C., the fluidity of the ink is impaired, and the printability and the gloss of the printed matter are remarkably deteriorated.

  Furthermore, the binder resin used in the present invention has a weight average molecular weight of 10,000 to 100,000, preferably 10,000 to 80,000, more preferably 10,000 to 50,000. When the molecular weight is 10,000 or less, the viscoelasticity necessary for the ink cannot be obtained, and when it is 100,000 or more, the fluidity as the ink becomes insufficient.

The vegetable oils in the present invention are vegetable oils and / or compounds derived from vegetable oils, and in triglycerides of glycerin and fatty acids, at least one fatty acid is a fatty acid having at least one carbon-carbon unsaturated bond, and those Fatty acid monoesters obtained by ester reaction of saturated or unsaturated alcohols from triglycerides of the above, or fatty acid monoesters obtained by direct ester reaction of fatty acids of vegetable oils and monoalcohols, and ethers, and regenerated vegetable oils can also be used. The content of vegetable oils is 1 to 60% by weight based on the total amount of the printing ink composition. Typical vegetable oils relating to the present invention are: Asa seed oil, flaxseed oil, eno oil, Eutiska 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, daiko oil, camellia oil, corn oil, rapeseed oil , Niger oil, nutka 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, and their thermopolymerized oil and oxygen Blow polymerization oil can also 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.

  Furthermore, if a suitable vegetable oil is mentioned, the vegetable oil whose iodine value is at least 100 or more is preferable, and the vegetable oil whose iodine value is 120 or more is more preferable. By setting the iodine value to 120 or more, it is possible to improve the drying property by oxidative polymerization of the ink film. However, even if the vegetable oil has an iodine value of less than 100, the drying property when the ink is made can be adjusted by adjusting the blending ratio of the metal dryer and the antioxidant used in the ink.

  The petroleum solvent used 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 to 340 ° C. The thing in the range of ° C 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. 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.

  The petroleum solvent used in the present invention is desirably contained in an amount of 0 to 25% by weight, preferably 0 to 20% by weight, more preferably 0 to 15% by weight, based on the total amount of the ink, if necessary. However, petroleum-based solvents cannot be used in the case of environment-friendly VOC-free inks.

  In general, printing inks other than VCO-free are often dried by oxidative polymerization of vegetable oils having unsaturated bonds in the ink and penetration of volatile petroleum solvents, workability during printing, Considering workability at the time of processing after printing, a certain degree of speed is required for setability on the printed matter and ink drying property. VOC-free inks that do not contain any volatile petroleum solvents will inevitably contain vegetable oils, and vegetable oils with higher viscosity than petroleum solvents will have a slower penetration due to capillary action on paper. There was a disadvantage that the setability of was inferior. In such a case, in addition to the vegetable oil described above, it is preferable to contain a fatty acid monoester derived from vegetable oil in an amount of 5 to 20% by weight based on the total weight of the ink. If the amount is less than 5% by weight, sufficient setting properties cannot be obtained, and if it exceeds 20% by weight, the ink has a low viscosity and printability is deteriorated.

  The fatty acid monoester is a fatty acid monoester obtained by transesterification of the above vegetable oil and monoalcohol or a direct ester reaction between the fatty acid of the vegetable oil and the monoalcohol. Typical examples of monoalcohol include methanol, ethanol, n- or iso-propanol, n, sec or tet-butanol, heptynol, 2-ethylhexanol, hexanol, octanol, decanol, dodecanol and other saturated alcohols, oleyl alcohol , Unsaturated fatty alcohols such as dodecenol, huseteri alcohol, somaryl alcohol, gadrelyl alcohol, 11-icosenol, 11-docosenol, 15-tetracosenol.

  The regenerated vegetable oil used in the present invention is applicable as long as it can be regenerated with the above-mentioned vegetable oils. In the present invention, the regenerated vegetable oil (regenerated vegetable oil) includes, for example, those recovered from the vegetable oil used for the production of tempura at restaurants, school lunches, vegetable shops, etc. However, it is not limited to these, and it is applicable if it can be regenerated with the vegetable oil after use.

  In addition, examples of the method for regenerating vegetable oil according to the present invention include methods such as filtration, precipitation by standing, and decolorization by activated clay, but the method is not particularly limited and is applicable.

Furthermore, the oxidative polymerization type 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, a non-ion as necessary. Additives such as system surfactants and polyhydric alcohols can be used as appropriate.
Examples of the pigment used in the present invention include general inorganic pigments and organic pigments. Examples of inorganic pigments include yellow lead, zinc yellow, bitumen, barium sulfate, cadmium red, titanium oxide, zinc white, dial, alumina white, calcium carbonate, ultramarine, carbon black, graphite, and aluminum powder. Organic pigments include azo pigments, soluble azo pigments such as C-based (β-naphthol-based), 2B-based and 6B-based (β-oxynaphthoic), β-naphthol-based, β-oxynaphthoic acid anilide-based, monoazo yellow-based, disazo Insoluble azo pigments such as yellow and pyrazolone, condensed azo pigments such as acetoacetate allylide, phthalocyanines, copper phthalocyanines (α blue, β blue, ε blue), copper halide phthalocyanines such as chlorine and bromine, metals Examples of free phthalocyanine pigments and polycyclic pigments include perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, and quinophthalone pigments. The addition amount of the pigment is 5 to 30% by weight with respect to the total amount of the offset printing ink.

  In addition, the oxidation polymerization type offset printing ink composition of the present invention can use various additives for the purpose of anti-friction, anti-blocking, slip and scratch prevention as other additives. An agent, an antistatic agent, a surfactant, an antifoaming agent, and the like may be added.

  Examples of the substrate used in the present invention include general printing paper such as coated paper and non-coated paper.

  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.

  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.

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” unless otherwise specified.
(Rosin modified phenolic resin production example 1)
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 was. 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%. X.

  Next, 1000 parts of gum rosin was charged into a four-necked flask equipped with a stirrer, a condenser with a water separator, and a thermometer, dissolved at 200 ° C. while blowing nitrogen gas, and 1800 parts of the resole liquid X produced above was dissolved. After adding and reacting at 230 ° C. for 4 hours while removing toluene, 110 parts of glycerin was added and reacted at 250 ° C. for 12 hours. By sequentially taking out in the course of the reaction, rosin-modified phenol resins A and B shown in Table 1 were obtained.

(Rosin modified phenolic resin production example 2)
To a four-necked flask equipped with a stirrer, a cooler, and a thermometer, add 1000 parts of p-tertiary butylphenol, 850 parts of 35% formalin, 60 parts of 93% sodium hydroxide, and 1000 parts of xylene, and at 95 ° C. for 4 hours. React. Then, 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 resol type phenol resin having a nonvolatile content of 52%. Y.

  Next, in a four-necked flask equipped with a stirrer, a condenser with a water separator, and a thermometer, 1000 parts of gum rosin was charged and dissolved at 200 ° C. while blowing nitrogen gas, and 1400 parts of resole liquid Y was added. After reacting at 230 ° C. for 4 hours while removing xylene, 120 parts of pentaerythritol was added and reacted at 240 ° C. for 16 hours. By sequentially taking out in the course of the reaction, rosin-modified phenol resins C and D shown in Table 1 were obtained.

(Varnish production example 1)
A four-necked flask equipped with a stirrer, a cooler and a thermometer, 43 parts of rosin-modified phenolic resin A (acid value 25, softening point 140, weight average molecular weight 10500), 36 parts of soybean oil, AF Solvent No. 5 (New Japan) Petroleum Co., Ltd., aniline point 88 ° C, boiling range 279-307 ° C) 20 parts, charged to 190 ° C, stirred at the same temperature for 30 minutes, allowed to cool, and ethyl acetoacetate aluminum as a gelling agent Charge 1 part of diisopropoxide (ALCH manufactured by Kawaken Fine Chemical Co., Ltd., hereinafter referred to as ALCH) and stir at 190 ° C. for 60 minutes to obtain gel varnish 1 (hereinafter referred to as varnish 1) for oxidation polymerization type offset printing ink. It was.

  Furthermore, based on the composition of Table 2, the gel varnishes 2-4 (henceforth varnishes 2-4) were obtained with the gel varnish manufacturing method equivalent to the above.

(Varnish production example 2)
A four-necked flask equipped with a stirrer, cooler, and thermometer was charged with 46 parts of rosin-modified phenolic resin A, 38 parts of regenerated vegetable oil, and 15 parts of soybean oil fatty acid butyl ester, heated to 190 ° C., and stirred at the same temperature for 30 minutes. After cooling, 1 part of ALCH (ALCH manufactured by Kawaken Fine Chemicals Co., Ltd., hereinafter referred to as ALCH) was added, and stirred for 60 minutes at 190 ° C., and gel varnish 5 for oxidation polymerization type offset printing ink (hereinafter referred to as varnish 5). )

  Furthermore, based on the composition of Table 3, gel varnishes 5-8 (hereinafter referred to as varnishes 5-8) were obtained by the same gel varnish production method as above.

(Ink production example)
17 parts of LIONOL BLUE FG7330 (manufactured by Toyo Ink Co., Ltd.), 1 part of commercially available wet method silica 1 (average secondary particle size 8.5 μm, BET specific surface area 210 m ² / g), 70 parts of varnish 1 and large 4.5 parts soybean oil, 5 parts wax compound (manufactured by Toyo Ink Co., Ltd.), 1.5 parts metal dryer (MK dryer made by Toyo Ink Co., Ltd.), drying inhibitor (manufactured by Toyo Ink Co., Ltd.) Example 1 of an oxidation polymerization type flat offset ink composition was obtained by adding 1 part of a drying inhibitor CP) and using three rolls according to a conventional method.
Furthermore, based on the composition of Table 4, Examples 2 to 8 of oxidation polymerization type flat offset ink compositions were obtained using three rolls according to a conventional method. In the present specification, Examples 1 to 6 and 9 to 16 are reference examples.

  Similarly, based on the composition of Table 5, Examples 9 to 16 of the oxidation polymerization type flat offset ink composition using three rolls according to a conventional method are obtained, and Comparative Examples 1 to 8 are obtained based on the composition of Table 6. It was.

  The produced oxidation polymerization type flat offset ink composition was evaluated below.

<Performance evaluation test (1) Ink fluidity>
The raw ink was set in a 2.1 cc hemispherical container, the ink was dropped on an inclined plate inclined at 60 °, the length that flowed in 10 minutes was measured, and the evaluation was performed based on the following evaluation criteria. . Higher values indicate better ink fluidity.
(Evaluation criteria)
○: 30 mm or more Δ: 5 mm or more and less than 30 mm ×: less than 5 mm The practical level is Δ or more.

<Performance evaluation test (2) 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 and less than 15% Δ: 15 or more and less than 20% ×: 20% or more The practical level is Δ or more.

<Performance Evaluation Test (3) Emulsification Fluidity>
While stirring 18 g of ink with a disper, 2 g of distilled water is gradually added and forcedly emulsified at 1200 rpm for 3 minutes. The emulsified ink was set in a 2.1 cc hemispherical container, the ink was dropped on an inclined plate inclined at 60 °, and the length that flowed in 10 minutes was measured and evaluated based on the following evaluation criteria. . The higher the value, the better the fluidity of the emulsified ink.
(Evaluation criteria)
○: 30 mm or more Δ: 5 mm or more and less than 30 mm ×: less than 5 mm The practical level is Δ or more.

<Performance evaluation test (4) Ink residue>
Komori Corporation sheet-fed printing press Lislon 26 prints with a general pattern and density, increasing the water dial value by 2 points from the water dial value that eliminates background stains. The printing press was stopped by raising the point by 20 points, and the ink remaining on the ink roller was visually observed and evaluated based on the following evaluation criteria.
(Evaluation criteria)
○: Ink residue is not recognized, and stable printing quality can be secured. Δ: Ink residue is recognized. X: Ink residue is remarkably large, and the printing quality is affected.

<Performance evaluation test (5) Concentration stability>
Komori Corporation sheet-fed printing press Lislon 26 prints with a general pattern and density, increasing the water dial value by 2 points from the water dial value that eliminates background stains. The point was raised by 5 points and 10 points, and the evaluation was carried out based on the following evaluation criteria from the change in concentration at that time.
(Evaluation criteria)
○: The concentration change average is ± 0.05 or less when the water dial increases by 5 points, 10 points is increased by ± 0.1 or less △: The average concentration change is ± 0.11 or less when the water dial increases by 5 points, 10 Point rise: ± 0.2 or less ×: The average concentration change is ± 0.21 or less when the water dial rises 5 points, 10 points rises ± 0.3 or less The practical level is Δ or more.

(Printing conditions)
Version: CTP plate for flat plate HP-F (Fuji Film Graphic Systems Co., Ltd.)
Paper: OK coat (Oji Paper Co., Ltd.)
Printing speed: 10,000 sheets / hour Dampening water: AQUAUNITY C 2.0% (manufactured by Toyo Ink Co., Ltd.)
Density: X-Rite 938, Status E, blank paper standard, measured without polarizing filter Yellow 1.40, Red 1.50, Indigo 1.60, Black 1.75 (adjusted within ± 0.05)
Adjustment)
Table 7 shows the results of the performance evaluation test.

When synthetic amorphous silica is not added or is added in a small amount, the emulsification fluidity is remarkably deteriorated. On the contrary, if it is added too much, the emulsification rate is extremely increased and there is no problem with the fluidity after emulsification, but the fluidity of the raw ink is poor and the stability with time of the ink is deteriorated.
As described above, it has been found that the examples relating to the present invention provide an offset ink having excellent fluidity and stability with time and emulsification stability during printing.

Claims (3)

A method for producing an oxidative polymerization offset printing ink composition comprising amorphous silica, rosin-modified phenolic resin, vegetable oil, petroleum solvent and pigment,
The amorphous silica comprises synthetic amorphous silica produced by a dry process with an average secondary particle size of 0.05 to 10 μm and a BET specific surface area of 20 to 400 m ² / g;
And the manufacturing method of the oxidation polymerization type offset ink composition characterized by containing 0.1 to 10weight% of amorphous silica with respect to the total weight of ink. Rosin modified phenolic resin
Acid value 5-30 (mgKOH / g),
Softening point 120-300 ° C by ring and ball method
And a weight average molecular weight of 10,000 to 100,000
The method for producing an oxidation polymerization type offset ink composition according to claim 1. According to claim 1 or 2 methods for producing printed material formed by printing onto a substrate manufacturing method obtained in oxidative polymerization type offset ink composition according to.