JP4835057B2 - Pigment composition for lithographic printing ink and lithographic printing ink using the same - Google Patents

Description

  The present invention relates to a pigment composition capable of providing the above-described lithographic printing ink excellent in emulsification suitability during lithographic printing with less bleeding into dampening water and a low emulsification rate.

  In lithographic printing, the fountain solution is present not only in the fountain solution alone but also in an emulsified state (emulsified ink) with the lithographic printing ink. Depending on the liquid nature of the fountain solution, a phenomenon in which a part of the organic pigment component in the lithographic printing ink is transferred to the fountain solution is observed. This phenomenon is called bleeding in the fountain. When bleeding to the fountain solution is significant, the fountain solution is colored, and light coloring occurs in portions other than the pattern necessary for the printed matter such as paper (background stain), making it impossible to obtain a clear printed matter.

  Patent Document 1 discloses a pigment water paste for a lithographic printing ink containing an organic pigment and a tertiary amine or a salt thereof in which at least two of the three hydrocarbon groups are hydrocarbon groups having 10 to 18 carbon atoms. Is described.

  However, in Patent Document 1, a polyoxyethylene fatty acid ester-based nonionic surfactant having an HLB of the present invention in a specific range is not used. If the nonionic surfactant is not contained in the pigment water paste, the lithographic printing ink using the pigment water paste does not sufficiently satisfy the bleed to dampening water and the emulsification rate during printing. A product having excellent emulsification ability was not obtained.

  Patent Document 2 describes a lithographic printing ink pigment composition containing an organic pigment and a nonionic surfactant having an HLB in a specific range.

  However, in Patent Document 2, the tertiary amine having a specific structure according to the present invention or a salt thereof is not used. Moreover, the HLB of the nonionic surfactant is 15 or less. A lithographic printing ink using a pigment composition that does not contain a tertiary amine having a specific structure or a salt thereof and contains only a nonionic surfactant having an HLB of 15 or less has a low emulsification rate during printing. No bleed to fountain solution was obtained with excellent emulsification ability.

JP 2002-356541 A (2nd page claim, 2nd page paragraph number 0006, 6th page paragraph number 0062-7th page paragraph number 0066). Japanese Unexamined Patent Application Publication No. 2004-267331 (claims on the second page, paragraph number 0009 on the third page, paragraph numbers 0021 and 0022 on the fourth page).

  The problem to be solved by the present invention is a lithographic printing ink pigment composition that has a small bleed to fountain solution at the time of lithographic printing and has a low emulsification rate, that is, excellent emulsification suitability, and contains the pigment composition An object of the present invention is to provide a lithographic printing ink.

  Therefore, as a result of intensive studies in view of the above-mentioned circumstances, the present inventors, in a pigment composition for preparing a lithographic printing ink, a polyoxyethylene fatty acid ester nonionic surfactant having an HLB in a specific range, It has been found that the above-mentioned problems can be solved by combining a tertiary amine having a specific structure or a salt thereof, and has completed the present invention.

  That is, the present invention relates to an organic pigment, a polyoxyethylene fatty acid ester nonionic surfactant having an HLB in the range of 15 to 40, and at least two of the three hydrocarbon groups having 10 to 18 carbon atoms. The present invention provides a lithographic printing ink pigment composition containing a tertiary amine which is a hydrocarbon group or a salt thereof, and a lithographic printing ink comprising the pigment composition.

The pigment composition of the present invention contains a polyoxyethylene fatty acid ester nonionic surfactant having an HLB in a specific range and a tertiary amine having a specific structure or a salt thereof, and therefore a lithographic plate obtained using the same Since printing ink has a small bleed to fountain solution and a low emulsification rate during printing, it has a particularly remarkable effect of being superior in emulsification suitability.
Therefore, the pigment composition of the present invention is optimal for lithographic printing ink applications.

  Details of the present invention will be described below.

  The lithographic printing ink pigment composition of the present invention comprises an organic pigment, a polyoxyethylene fatty acid ester nonionic surfactant having an HLB in the range of 15 to 40, and at least two of the three hydrocarbon groups. It is characterized by comprising a tertiary amine which is a hydrocarbon group having 10 to 18 carbon atoms or a salt thereof.

  The pigment composition of the present invention comprises an organic pigment and water as main components, an additive component, a polyoxyethylene fatty acid ester-based nonionic surfactant having an HLB in the range of 15 to 40, and three carbonizations. A pigment water paste containing a tertiary amine or a salt thereof, wherein at least two of the hydrogen groups are hydrocarbon groups having 10 to 18 carbon atoms, or the drying step or the drying step and pulverizing step of the pigment water paste described above However, a pigment water paste is preferable.

  Any known organic pigment can be used as the organic pigment of the present invention. Examples thereof include azo lake pigments, phthalocyanine pigments, quinacridone pigments, diketopyrrolopyrrole pigments, and the like. These may have been subjected to various surface treatments. In particular, the addition of a polyoxyethylene fatty acid ester-based nonionic surfactant having a HLB in a specific range and a tertiary amine having a specific structure greatly enhances the flash property and the effect of preventing over-emulsification of the ink. In view of this, an azo lake pigment is preferable.

  Examples of the azo lake pigment include a azo dye obtained by coupling a diazonium salt of an aromatic amine having a water-soluble group and a coupler component with an alkaline earth metal salt.

  Examples of the aromatic amine having a soluble group include 4-aminotoluene-3-sulfonic acid (4B acid: p-toluidine-m-sulfonic acid), 4-amino-2-chlorotoluene-5-sulfonic acid (2B). Acid), 3-amino-6-chlorotoluene-4-sulfonic acid (C acid), 1-amino-4-methylbenzene-3-sulfonic acid, 2-aminonaphthalene-1-sulfonic acid (tobias acid), 1 -Amino-3-methylbenzene-4-sulfonic acid and the like.

  The coupler component is typically 3-hydroxy-2-naphthoic acid (β-oxynaphthoic acid), but may be β-naphthol or acetoacetanilide. Moreover, the derivative of the said coupler component, for example, the compound substituted by the lower alkyl group, the alkoxy group, or the halogen atom may be sufficient.

  Examples of the alkaline earth metal salt include calcium chloride, barium chloride, strontium chloride and the like.

  Examples of the azo lake pigment include C.I. I. And monoazo lake pigments such as Pigment Red 48: 1, 48: 2, 48: 3, 52: 1, and 57: 1. Among them, the binding force between the monoazo dye portion constituting the pigment and calcium ions is weak, and it is easily converted into a monoazo dye in an acidic aqueous solution. I. Pigment Red 57: 1 is preferable in that the effect of improving bleeding resistance is remarkable.

  The organic pigment used in the present invention is C.I. I. In the case of Pigment Red 57: 1, for example, various rosins selected from rosin mainly composed of abietic acid, hydrogenated rosin, disproportionated rosin, polymerized rosin, fumaric acid modified rosin and maleic acid modified rosin are produced. Use of the material added and processed in the process is preferable in that a lithographic printing ink excellent in transparency and coloring power can be obtained and the effect of improving the flushing property is great.

  When the organic pigment used in the present invention is an azo lake pigment, an aqueous solution containing a coupler component and an aqueous solution containing a diazonium salt component are injected into a suspension of polyvalent metal salts of rosins to obtain rosins. After the coupling reaction in the presence of fine particles of polyvalent metal salt, rake formation is performed, and azo lake pigments with a smaller length-to-width ratio can be produced. This is preferable in that a colored film having a small value, excellent fluidity and high gloss can be obtained.

  The rosin polyvalent metal salt is a salt composed of the rosin and a divalent, trivalent or tetravalent polyvalent metal, such as a Ca salt, Ba salt, Sr salt, Al salt, Zn Examples include salts. This polyvalent metal salt is typically water-insoluble or sparingly water-soluble, unlike the corresponding monovalent metal salts such as Na salt and K salt. Especially, the calcium salt of rosins is preferable at the point with the high improvement effect of the flushing property at the time of preparing a lithographic printing ink, for example.

  The rosin polyvalent metal salt can be obtained by bringing the rosin into contact with a polyvalent metal salt or the like. Specifically, it can be obtained by bringing a Na salt aqueous solution or K salt aqueous solution of rosin into contact with an inorganic salt typified by calcium chloride, barium chloride, strontium chloride, aluminum chloride, zinc chloride or the like.

  The above-mentioned suitable manufacturing method can be implemented as follows, for example.

(1) The total amount of the aqueous solution containing the coupler component and the total amount of the aqueous solution containing the diazonium salt component are each separately divided into a plurality of parts, and the two parts separated so that the apparent injection molar ratio of the two individual components is constant. A method of injecting an aqueous solution “alternatively” into an aqueous suspension of a polyvalent metal salt of rosins to cause a coupling reaction of all the components, and further to form a lake.
(2) The total amount of the aqueous solution containing the coupler component and the total amount of the aqueous solution containing the diazonium salt component are gradually “sequentially” mixed into the rosin polyvalent metal so that the apparent injection molar ratio of both components becomes constant. A method of injecting into an aqueous suspension of salt and subjecting all components to a coupling reaction, followed by rake formation.

  In any of these production methods, some coupler components may be included in advance in the aqueous suspension of the rosin polyvalent metal salt.

Furthermore, the couplings (1) and (2) can be performed in the following manner in order.
(A) A suspension of a rosin polyvalent metal salt is placed in a batch-type stirring tank, and an aqueous solution of a coupler component and an aqueous solution of a diazonium salt component are alternately supplied through separate injection tubes under this stirring. In the method, the following (a) and (b) are alternately repeated.
(A) An operation of supplying a part of the total amount of the aqueous solution of the coupler component through the injection tube.
(B) An operation of supplying a part of the total amount of the aqueous solution of the diazonium salt component through the injection tube.
(B) A suspension of a polyvalent metal salt of rosins is placed in a batch-type stirring tank, and an aqueous solution of a coupler component and an aqueous solution of a diazonium salt component are continuously supplied through separate injection tubes under this stirring. Method.

  The azo dye suspension treated with the polyvalent metal salt of rosin used for lake formation should be alkaline, especially pH 9-14, particularly preferably 12.5-14, because azo It is preferable in that the speed of the rake formation of the dye is appropriate, and pigment particles having a required particle diameter can be obtained while adjusting the particle form.

  The suspension containing the azo lake pigment treated with the polyvalent metal salt of rosin thus obtained by lake formation can be used as it is as an azo lake pigment. It is preferable to age at ~ 90 ° C for 30 minutes to 2 hours.

  When aging, the liquidity of the suspension containing the azo lake pigment treated with the polyvalent metal salt of rosin can be adjusted to acidic to alkaline, but when aging is carried out at pH 11 to 14, It is preferable in that it has the effect of adjusting the particle form as described above. The pH of the azo pigment suspension at the time of aging is preferably adjusted to be higher than the pH of the suspension of the azo dye treated with the polyvalent metal salt of rosins used for lake formation.

  The above-mentioned preferred method for producing an azo lake pigment and the combined treatment of a polyoxyethylene fatty acid ester nonionic surfactant having a HLB in the range of 15 to 40 and a tertiary amine or a salt thereof in the present invention are optimal. It is an embodiment.

  The nonionic surfactant used in the present invention is HLB, that is, a polyoxyethylene fatty acid ester-based nonionic surfactant having an index value of the balance between hydrophobicity and hydrophilicity in the range of 15 to 40. . Such nonionic surfactants are not particularly limited. For example, polyethylene glycol monostearate (Emanon 3199V, HLB19.4, manufactured by Kao Corporation), polyoxyethylene distearate (Kao Corporation) Emanon 3299V, HLB18.9) manufactured by company, polyoxyethylene distearate (Emanon 3299RV, HLB19.2 manufactured by Kao Corporation), polyoxyethylene sulfide castor oil (Emanon CH-80, HLB15 manufactured by Kao Corporation). In particular, polyoxyethylene distearate (Emanon 3299RV, HLB19. Manufactured by Kao Corporation) is considered in consideration of solubility in petroleum-based solvents and vegetable oils that are components of lithographic printing inks. 2) Polyoxyethylene sulfide castor oil (Kao stock) It is preferable to use Emanon CH-80, HLB 15.0) manufactured by a formula company.

  In the present invention, when the HLB described above is combined with a nonionic surfactant having a specific range and a tertiary amine or a salt thereof described later, the bleed to the dampening water is small at the stage of printing the lithographic printing ink. Moreover, the emulsification rate is low, that is, it exhibits an excellent effect due to emulsification suitability.

  If the HLB deviates from the above-described preferred range, bleeding to the fountain solution tends to increase. In addition, even if the HLB is in the preferred range described above, in the absence of a tertiary amine or a salt thereof described later, the emulsion rate is somewhat satisfactory, but the bleed to dampening water is sufficiently satisfactory. I can't get it.

  As an example of the pigment composition of the present invention, a pigment water paste is used as an example. An ink (a lithographic printing with a low emulsification rate) that does not become a state in which a large amount of dampening water is contained in the lithographic printing ink (a high water content of the emulsified ink) In order to obtain a pigment water paste that can provide (ink), there is an optimum range for the amount of the nonionic surfactant added.

  The addition amount of the nonionic surfactant is preferably in the range of 0.05 to 5 parts per 100 parts of the organic pigment in terms of mass, and more preferably in the range of 0.1 to 1 part. . When the addition amount of the nonionic surfactant deviates from the above preferred range, the emulsification inhibiting effect tends to decrease.

  When the organic pigment is produced in an aqueous system, the condition for adding the nonionic surfactant is preferably before the suspension of the organic pigment is filtered. When the organic pigment is an azo lake pigment, it is preferable to add it from the ripening step to immediately before the filtration step, from the end of the lake formation to the ripening step. Among these, it is more preferable to add the pigment suspension after the ripening step is finished after the ripening step is finished to the melting point of the surfactant or higher.

  The tertiary amine or salt thereof used in the present invention is a tertiary amine or salt thereof in which at least two of the three hydrocarbon groups are carbon hydrogen groups having 10 to 18 carbon atoms. The hydrocarbon group in the present invention may be linear, branched or cyclic, and may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The salt corresponding to the above-mentioned tertiary amine can be obtained by neutralizing the tertiary amine with acids. As these acids, inorganic acids such as oxalic acid, formic acid and hydrochloric acid, and organic acids such as acetic acid and propionic acid can be used.

  Hereinafter, this tertiary amine and its salt are collectively abbreviated as amine.

  This amine has (1) low hydrophilicity and thus little elution into dampening water, and high adsorption rate to the pigment surface. (2) effective basicity on the nitrogen atom, so that the pigment surface. (3) Two long hydrocarbon chains having 10 to 18 carbon atoms are hydrophobic and increase the density of the resin adsorption layer formed on the pigment surface. It is most preferable in terms of contributing to the above.

  All of the three hydrocarbon groups of the amine may have 10 to 18 carbon atoms, but one should be a hydrocarbon group having 1 to 8 carbon atoms, especially a hydrocarbon group having 1 to 4 carbon atoms. Is preferable from the viewpoint of the emulsification rate and bleeding properties described later.

  If the number of carbon atoms of the essential hydrocarbon group contained in one molecule is less than 10, the amine is highly hydrophilic and cannot sufficiently contribute to the formation of a resin adsorption layer on the pigment surface. It is difficult to improve. In addition, when the carbon number is 19 or more, the steric hindrance of the hydrogenated hydrogen chain is too strong, and the basicity on the nitrogen atom is not effectively expressed, so that it can contribute to the formation of a resin adsorption layer on the pigment surface. It is difficult to improve the bleed resistance.

  Examples of the tertiary amine that can be used in the present invention include didecyl monomethyl methyl amine, dilauryl monomethyl amine, dimyristyl monomethyl amine, dipalmityl monomethyl amine, distearyl methyl amine, didecyl monoethyl amine, dilauryl monoethyl amine. , Dipalmityl monoethylamine, distearyl monoethylamine, and the like.

  As a method for treating the nonionic surfactant and the tertiary amine into the organic pigment, for example, a suspension of the nonionic surfactant and the tertiary amine is individually prepared to prepare an aqueous solution of the organic pigment. It may be added to the suspension or oily suspension, or a suspension in which a nonionic surfactant and a tertiary amine are premixed is prepared, and these are added to an aqueous suspension of an organic pigment or It may be added to the oily suspension.

  As a method for treating tertiary amines with organic pigments, specifically, an emulsion or suspension obtained by forcibly stirring a tertiary amine with water using a stirrer or an emulsifier, a tertiary amine An aqueous suspension of an organic pigment or a solution obtained by emulsifying a surfactant with a surfactant, a solution in which a tertiary amine is solubilized with a surfactant, a solution in which a tertiary amine is dissolved in an organic solvent, or the like. It can be performed by adding to an oily suspension.

  In addition, as a method for treating a tertiary amine salt with an organic pigment, for example, an amine salt solution or suspension obtained by neutralizing a tertiary amine with an acid is used as an aqueous suspension or oil suspension of an organic pigment. This can be done by adding to the liquid.

  As the surfactant in preparing the emulsion, anionic surfactants and nonionic surfactants are preferably used. However, the use of a surfactant may affect the viscoelasticity of the lithographic printing ink. From this point, an emulsion or suspension obtained by forcibly stirring a tertiary amine with water by a stirrer or an emulsifier, or a tertiary amine neutralized with an acid such as acetic acid. It is preferred to add the salt solution or suspension to the aqueous or oily suspension of the organic pigment.

  In addition, when an amine salt solution or suspension obtained by neutralizing a tertiary amine with an acid is added to an aqueous suspension or oil suspension of an organic pigment, the organic pigment added with a tertiary amine salt is added. A base may be added to the aqueous suspension or oil suspension to return the salt of the tertiary amine to the original tertiary amine state.

  When the organic pigment is produced in an aqueous system, the amine may be added before the organic pigment suspension is filtered. When the organic pigment is an azo lake pigment, it is preferable to add it from the ripening step to immediately before the filtration step, from the end of the lake formation to the ripening step. Addition before rake is not recommended because the transparency of the lithographic ink is often impaired.

  Since amines often have a function of growing pigment crystals, the most preferable addition time is to add the liquid after the ripening process is completed, after the temperature of the pigment suspension is lowered from the aging temperature. good. When the organic pigment is an azo lake pigment, it is most preferable to add the amine to the suspension at 5 to 70 ° C.

  For example, a pigment water paste is used as an example of a pigment composition. An ink (a lithographic printing ink having a low emulsification rate) that does not become a state in which a large amount of dampening water is contained in the lithographic printing ink (a state in which the water content of the emulsification ink is high). In order to obtain a pigment water paste that can be provided, there is an optimum range for the type and addition amount of the tertiary amine.

  The addition amount of the amine is preferably in the range of 0.05 to 5 parts per 100 parts of the organic pigment in terms of mass, and more preferably in the range of 0.1 to 1 part. When the added amount of the amine is 0.05 parts or less, the bleed resistance decreases. On the other hand, if the added amount of amine is 5 parts or more, the effect of improving the bleed resistance is not changed, but the added amount exceeds that which contributes to the formation of the resin adsorption layer on the pigment surface. However, the coloring power of the finally obtained lithographic printing ink tends to decrease or the emulsification amount of the fountain solution tends to increase, which is not preferable.

  In the present invention, the mechanism for improving bleeding resistance by adding an amine is that (1) the pigment surface is hydrophobized by treating the fine particles of the pigment with a tertiary amine having a specific structure or a salt thereof. (2) A tertiary amine having a basic structure with a specific structure or a nitrogen atom of a salt thereof is adsorbed on the pigment surface, and a long hydrocarbon chain spreads in the vehicle. This is because the chain and the hydrophobic group in the vehicle have an affinity to help form a strong resin adsorbing layer on the pigment surface.

  Therefore, as is often done in the past, the above-mentioned HLB used in the present invention is a specific range of polyoxyethylene fatty acid ester-based nonionic surfactants in the production of lithographic printing inks, for example, in the flushing step. Even if a tertiary amine having a specific structure or a salt thereof is added, the effect of improving bleeding resistance is not sufficient. Furthermore, it is difficult to obtain a pigment water paste that can provide a lithographic printing ink with a low emulsification rate.

  That is, in the present invention, a polyoxyethylene fatty acid ester-based nonionic surfactant having a specific range and a tertiary amine having a specific structure or a salt thereof are added at the stage of pigment water paste or powder pigment. As a result, it is possible to effectively suppress bleeding into the fountain solution and to obtain a lithographic printing ink having a low emulsification rate as compared with the case where it is added at the stage of preparing a conventionally known lithographic printing ink.

  The amount of the organic pigment in the pigment water paste can be defined from the ease of handling. That is, when the amount of the organic pigment in the pigment water paste is small and a large amount of water is contained, the pigment water paste is liquefied, making it difficult to transport and prepare it for a kneading machine such as a flash kneader. Further, when the amount of the organic pigment in the pigment water paste is large, the pigment water paste becomes stiff and a load such as a flash kneader is applied, which is not preferable.

  For the above reason, the ratio of the organic pigment in the pigment water paste is 25.0 to 150.0 parts, preferably 33.3 to 100 parts, most preferably 42.9 to 100 parts of water in terms of mass. 66.7 parts. In terms of the concentration of the organic pigment, if the total of the above-mentioned nonionic surfactant, amine, organic pigment and water is 100%, it is 20 to 60%, preferably 25 to 50%, most preferably 30 ~ 40%.

  The pigment composition of the present invention, particularly the pigment water paste, can be used in a lithographic printing ink after being kneaded together with a printing ink vehicle by a kneader such as a flash kneader, an extruder or a continuous kneader. Specifically, a pigment water paste containing an organic pigment and a vehicle are kneaded, the organic pigment is transferred to the vehicle to release and remove water, and then the water remaining in the mixture of the organic pigment and the vehicle is dehydrated under reduced pressure. Is removed to produce a lithographic ink.

  Vehicles used for lithographic printing inks include, for example, resins such as rosin modified phenolic resin, petroleum resin, alkyd resin, vegetable oils such as linseed oil, tung oil, soybean oil, n-paraffin, isoparaffin, aromatic, naphthene, α -What consists of petroleum solvents, such as an olefin, is mentioned. However, there is a growing interest in global environmental issues, that is, the aim of building a society that does not depend on oil, and the viewpoint of selecting substances that are highly biodegradable and that have a high biodegradability and a short period of time in the environment. Therefore, the use of petroleum solvents such as n-paraffins, isoparaffins, aromatics, naphthenes and α-olefins in this vehicle is being avoided.

  Therefore, for lithographic printing inks comprising a resin such as rosin modified phenolic resin, petroleum resin, alkyd resin and soy oil without containing petroleum solvents such as n-paraffin, isoparaffin, aromatic, naphthene, α-olefin, etc. It is preferable to use a vehicle.

  The lithographic printing ink prepared using the pigment composition of the present invention, especially the pigment water paste, is added with a conventionally known nonionic surfactant, primary, tertiary amine or a salt thereof at the time of ink preparation. Since it is not necessary, there is no inconvenience caused when they are added in a large amount during ink preparation. Bleed resistance and low emulsification with less content than before, even when compared with the types of nonionic surfactants, tertiary amines or their salts that are eventually included in final lithographic printing inks An excellent effect of combining the amount (low emulsification rate) is exhibited.

  The pigment composition of the present invention thus obtained is used to prepare a lithographic printing ink, and is then subjected to lithographic printing using this lithographic printing ink and a known common fountain solution.

  The fountain solution can be prepared by diluting a concentrated fountain solution having a high component content with water, for example, 30 to 60 times.

  The fountain solution stock is composed of, for example, a water-soluble polymer compound, a surfactant, a surface conditioner that removes the surface oxide of the plate, a dynamic surface tension reducing agent, a plate corrosion inhibitor, and the like. Examples of water-soluble polymer compounds include gum arabic, carboxymethyl cellulose, polysaccharides, various modified starches, vinyl acetate-acrylic acid copolymers, polyvinyl alcohol-maleic acid copolymers, and the like. Nonionic surfactants, etc. As surface conditioners, phosphoric acid, citric acid, etc. As dynamic surface tension reducing agents, for example, monoalcohols, polyhydric alcohols, ethers, esters, etc., plate corrosion Examples of the inhibitor include ammonium dichromate and nitrate. A fountain solution can be prepared by mixing these with water in a necessary mass proportion according to common knowledge of those skilled in the art.

  Generally, the main ingredient of the fountain solution stock solution is prepared with water / dynamic surface tension reducing agent = 25 to 75/75 to 25 (mass ratio), and various additives described above are appropriately added thereto. Then, use the fountain solution solution. Of course, in printing using the lithographic printing ink obtained from the pigment composition of the present invention, it is possible to use a fountain solution obtained by diluting a commercial fountain solution stock with water.

  Azo lake pigments tend to release the raked metal under acidic conditions and transfer to the azo dye prior to rake formation, but the lithographic printing ink obtained using the pigment composition of the present invention has a specific pigment and HLB. Due to the stronger interaction between the surfactant in the range and the amine having a specific structure, it is difficult to elute into the fountain solution used during lithographic printing even under stronger acidic conditions. Accordingly, even in lithographic printing using a fountain solution having a low pH range, for example, a pH of 5 or less, printing with a lithographic printing ink prepared from the pigment composition of the present invention has very little coloring of the fountain solution. It is possible to obtain a clear printed matter with less background stains other than the pattern necessary for the printed matter.

  Now, as the printing speed increases, it has been required to uniformly supply dampening water to the hydrophilic portion on the plate rotating at high speed. Conventionally, the surface tension (dynamic surface tension) of the fountain solution is reduced by supplying 10 to 40% of isopropyl alcohol, which is a dynamic surface tension reducing agent, in the fountain solution, and the fountain solution is supplied uniformly. However, the use of isopropyl alcohol has been restricted for the purpose of improving the working environment and the global environment at the printing site.

  That is, according to the Occupational Safety and Health Act (Organic solvent poisoning prevention regulations), dampening water containing 5% or more of isopropyl alcohol (IPA) is subject to the law and is obliged to install local ventilation equipment, A medical checkup is mandatory. In addition, IPA is a dangerous substance (Class 4 petroleum) and is subject to regulations of the Fire Service Act for storage and use, and IPA-containing dampening water that exhibits a high biochemical oxygen demand (BOD) is applicable to the Sewerage Law. The use of isopropyl alcohol has been restricted from the standpoint of increasing the cost of the printer, such as receiving a print.

  As a result, the fountain solution currently used is blended with an additive (IPA alternative additive) in place of isopropyl alcohol as a dynamic surface tension reducing agent. The fountain solution currently widely used in the printing field is a fountain solution containing no isopropyl alcohol (non-IPA fountain solution) or a fountain solution containing less than 5% by mass of isopropyl alcohol ( IPA reduced dampening water).

  The lithographic printing ink prepared using the pigment composition of the present invention can be used in any case where lithographic printing is performed using the non-IPA dampening water or the IPA-reduced dampening water. Since the bleed is small and the emulsification rate on a printing press is low, the emulsification suitability is excellent.

  Hereinafter, the present invention will be described in detail by way of examples and comparative examples. The present invention is not limited to these examples. Unless otherwise specified, both “part” and “%” are based on mass.

  After dispersing 38.5 parts of 2-amino-5-methylbenzenesulfonic acid in 200 parts of water, 25 parts of 35% hydrochloric acid was added, and 36.8 parts of 40% sodium nitrite aqueous solution was added dropwise while maintaining at 0 ° C., and diazonium. A salt solution was obtained. Next, 40.1 parts of 2-hydroxy-3-naphthoic acid was dispersed in 250 parts of warm water at 50 ° C., and then 77.9 parts of a 25% aqueous sodium hydroxide solution was added to obtain a coupler solution. After cooling the coupler solution to 10 ° C., the diazonium salt solution was added dropwise with stirring. The coupling reaction was terminated by stirring at 10 ° C. for 60 minutes to obtain a dye suspension.

  To the dye suspension was added 32.4 parts of 25% tall oil rosin K salt solution (8.1 parts as tall oil rosin). After stirring for 30 minutes, a solution prepared by dissolving 46.6 parts of 72% calcium chloride in 55 parts of water was added, and the mixture was stirred for 60 minutes to complete rake formation. After completion of the rake reaction, the mixture was stirred while being heated at 25 ° C. for 90 minutes to obtain a suspension of calcium lake azo pigment (CI Pigment Red 57: 1) in water. The aging step was completed by stirring for 90 minutes after heating to 85 ° C. Ice was added, and the liquid temperature was cooled to 60 ° C., and then the pH was adjusted to 7.6 using hydrochloric acid.

  0.09 parts Farmin M2-2095 (tertiary amine based on dilauryl monomethylamine manufactured by Kao Corporation) and 0.24 parts Emanon 3299RV (non-ionic surfactant manufactured by Kao Corporation, poly Oxyethylene distearate (HLB19.2) was added to 0.15 part of 90% acetic acid and 5 parts of hot water, and then stirred at high speed using a homomixer to prepare a suspension containing a nonionic surfactant. These suspensions were added to the above-mentioned calcium lake azo pigment (CI Pigment Red 57: 1) in water and stirred at 60 ° C. for 30 minutes.

  Then, it heated to 60 degreeC and stirred for 1 hour. Filtration and washing with water gave a pigment water paste 1.

(Comparative Example 1)
In Example 1, pigment water paste 2 was obtained in the same manner as in Example 1 except that 2.4 parts of polyoxyethylene distearate (nonionic surfactant, Emanon 3299RV manufactured by Kao Corporation) was not used. It was.

(Comparative Example 2)
In Example 1, pigment water paste 3 was obtained in the same manner as in Example 1 except that 0.9 part of dilauryl monomethylamine (tertiary amine manufactured by Kao Corporation, Farmin M2-2095) was not used.

(Comparative Example 3)
In Example 1, 0.9 part of dilauryl monomethylamine (tertiary amine manufactured by Kao Corporation, Farmin M2-2095) and polyoxyethylene distearate (nonionic surfactant manufactured by Kao Corporation) 2 A pigment water paste 4 was obtained in the same manner as in Example 1 except that 4 parts were not used.

(Ink creation 1)
Each simulated lithographic printing ink was prepared using each pigment water paste obtained in Example 1 and Comparative Examples 1, 2, and 3. First, 200 parts of a lithographic printing ink vehicle and each pigment water paste corresponding to 100 parts of dry solid content at 90 ° C. were charged into a 1 L flash kneader, the 1 L flash kneader was operated, and flushing was performed at 60 ° C. After the generated flushing waste water was removed, dehydration by heating under reduced pressure at 100 ° C. and 70 mmHg for 1 hour was performed. After cooling to 65 ° C., 84.6 parts of vehicle was added to prepare a base ink for lithographic printing ink. Furthermore, using three rolls, 66 parts of this base ink was kneaded and dispersed together with 34 parts of the vehicle to prepare each simulated lithographic printing ink 1-4.

(Creating non-IPA dampening water)
6.0 parts of a composition comprising 35.5 parts of water, 1.5 parts of phosphoric acid, 1.7 parts of magnesium nitrate, 65.0 parts of ethylene glycol monobutyl ether (butyl cellosolve) and 0.5 part of gum arabic were added to 100 parts of water. To make a non-IPA fountain solution (pH 4.5).

(Bleed resistance test 1)
Prepared by using the simulated lithographic printing ink 1 prepared using the pigment water paste 1 and the ink 2 prepared using the pigment water paste 2 and the pigment water paste 3 obtained by the method described in Ink Preparation 1. The same ink 4 prepared using the same ink 3 and the pigment water paste 4 was subjected to a bleed resistance test by the following method.

  First, 10 parts of each simulated lithographic printing ink and 100 parts of non-IPA fountain solution were mixed with a high-speed stirrer, and the degree of coloring of the filtrate was changed to ◎ (particularly good), ○ (good), △ (somewhat good), × ( Evaluation was divided into four stages (bad). A: The bleed is small and the filtrate is not colored, and the bleed resistance means particularly good. ○: The bleed is small, but the filtrate is slightly colored, and the bleed resistance means good. Δ indicates that the bleed is slightly larger and the filtrate is colored, and the bleed resistance means slightly better. X indicates a state in which the bleed is large and the filtrate is also intensely colored, and the bleed resistance means poor. The results are shown in Table 1.

                    Table 1

  As is clear from the results in Table 1, the simulated lithographic printing ink 1 prepared using the pigment composition of the present invention (pigment water paste) has a small bleed and no coloration of the filtrate. Was particularly good. On the other hand, the ink containing a tertiary amine having a specific structure or a salt thereof had a small bleed (slight scattering was observed), but the filtrate was slightly colored and the bleed resistance was good. The HLB has a specific structure within a specific range, the ink does not contain any of the amine and the nonionic surfactant (no treatment), and the bleed becomes large (spattering is observed). The coloring also increased, and the bleed resistance was slightly good to poor.

(Emulsification test)
An emulsification test was conducted using each simulated lithographic printing ink. As a printing test method, 50 parts of lithographic printing ink and 50 parts of non-IPA fountain solution are charged into a Duke emulsification tester (Duke emulsification tester: INK-WATER EMULSIFICATION TESTER, DUKE CUSTOM SYSTEMS INC. MODEL D-10). , Mixed. 15 minutes after the start of mixing, the amount of water released without emulsification was measured, and the amount of emulsified water was calculated.

  A pigment water paste that gives a lithographic printing ink with a small amount of emulsified water 15 minutes after mixing is judged to be a pigment water paste that gives a lithographic printing ink with a small amount of emulsification. The results are shown in Table 2.

                    Table 2

As is clear from the results in Table 2, a simulated lithographic printing ink 1 prepared using the pigment composition of the present invention (pigment water paste 1) and a nonionic surfactant having a specific structure within a specific range of HLB Although the emulsified amount of the ink contained was small, any of the ink containing a tertiary amine or a salt thereof having a specific structure, the amine or a salt thereof and the nonionic surfactant (no treatment) The amount of emulsification was large. In addition, an ink containing a tertiary amine having a specific structure or a salt thereof and an untreated ink had an equivalent emulsification amount.
Furthermore, the amount of emulsification usually increases and fluctuates as the mixing time of the Duke emulsification tester becomes longer, whereas the simulated lithographic printing ink 1 prepared using the pigment composition of the present invention (pigment water paste 1) From the fact that the increase / fluctuation of the emulsification amount is small (emulsification rate is low), it was found that a lithographic printing ink capable of stable printing can be provided.

The pigment composition of the present invention (pigment water paste) contains a polyoxyethylene fatty acid ester-based nonionic surfactant having an HLB in a specific range and a tertiary amine having a specific structure or a salt thereof. Since the lithographic printing ink obtained by using the ink has a small bleed to fountain solution during printing and a low emulsification rate, it has a particularly remarkable effect of being superior in emulsification suitability.
Therefore, the pigment composition of the present invention is optimal for lithographic printing ink applications.

Claims (6)

An organic pigment, a polyoxyethylene fatty acid ester-based nonionic surfactant having an HLB in the range of 15 to 40, and at least two of the three hydrocarbon groups are hydrocarbon groups having 10 to 18 carbon atoms A lithographic printing ink pigment composition comprising a tertiary amine or a salt thereof. The pigment composition according to claim 1, wherein the polyoxyethylene fatty acid ester nonionic surfactant having an HLB in the range of 15 to 40 is polyoxyethylene distearate or polyoxyethylene sulfide castor oil. The pigment composition according to claim 1, wherein the organic pigment is an azo lake pigment. The organic pigment is C.I. I. The pigment composition according to any one of claims 1 to 3, which is Pigment Red 57: 1. 0.05 to 5 parts of polyoxyethylene fatty acid ester-based nonionic surfactant having an HLB in the range of 15 to 40 per 100 parts of organic pigment by mass, at least two of the three hydrocarbon groups are carbon The pigment composition according to any one of claims 1 to 4, wherein the tertiary amine which is a hydrocarbon group having 10 to 18 atoms or a salt thereof is 0.05 to 5 parts. A lithographic printing ink comprising the pigment composition according to any one of claims 1 to 5.