JPH11199819A - Water droplet in oil type emulsion ink for mimeographic printing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject ink having an aqueous phase as a phase separated dispersion state in an oil phase by using an emulsifier, improving a phenomenon of a 'transition to the rear surface' by containing solid particles having a larger mean particle diameter than the film thickness of a phase containing a coloring agent on a paper in the reverse phase reversal to the phase containing the coloring agent. SOLUTION: This water droplet in oil type emulsion ink for a mimeographic printing machine having an aqueous phase as a phase-separated dispersion state in an oil phase by using an emulsifier, is obtained by containing solid particles having >=20 fold of a mean particle diameter of a coloring agent, preferably 8-30 μm particle diameter (e.g.; a polyethylene, polyester, polypropylene, or the like) in a reverse phase (preferably an aqueous phase) reversal to a phase containing the coloring agent (preferably an oil phase) by 0.5-30 wt.% based on the total amount of the ink. As the above coloring agent, a pigment or the like, such as carbon black, titanium oxide and an azo- based dyestuff can be used, and the amount of its addition is 1-15 wt.%, preferably 2-10 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a water-in-oil emulsion ink for a stencil printing machine.

[0002]

2. Description of the Related Art As is well known, a stencil printing method uses a stencil sheet, and moves ink from one side of the stencil to the other side of the stencil through an opening of the stencil sheet. The printing is performed on the surface of the printed material. In this printing method, since the printed matter immediately after printing is superimposed on the paper discharge tray, the phenomenon that the undried ink of the previous printed matter adheres to the back surface of the printing unit, so-called "offset" is an unavoidable problem.

In order to improve the above “set-off”, Japanese Patent Application Laid-Open
JP-A-116525 proposes to mix a colorant and solid particles having an average particle diameter of 8 to 30 μm in an oil phase. However, if the colorant and the solid particles are in phase,
The colorant also adheres to the surface of the solid particles, causing a “set-off”
Is not effective enough. Also, JP-A-8-2
No. 18025 discloses an extender in an aqueous phase.
Japanese Patent Publication No. 302262 proposes that an extender is contained in an oil phase. However, since the extender used in both proposals is as small as 1.6 μm to 3.5 μm, “offset” is not considered. A sufficient effect cannot be obtained.

[0004]

Therefore, the present invention provides
An object of the present invention is to provide a water-in-oil emulsion ink for a stencil printing machine with improved "set-off".

[0005]

According to the present invention, (1)
In the oil phase, in a water-in-oil emulsion ink for a stencil printing machine in which the aqueous phase is dispersed and dispersed using an emulsifier,
The reverse phase of the phase containing the colorant has an average particle diameter of 2 of the colorant.
A water-in-oil emulsion ink for a stencil printing machine characterized by containing solid particles having an average particle diameter of 0 times or more. (2) In the above (1), a colorant is added to the oil phase, and A water-in-oil emulsion ink for a stencil printing press, comprising solid particles having an average particle diameter of 20 times or more the average particle diameter of the colorant. (3) The water-in-oil emulsion ink for a stencil printing machine according to the above (1), wherein the average particle diameter of the solid particles is 8 to 30 μm.

[0006] In a stencil printing machine, it is said that an ink coating is formed on the paper surface immediately after printing, and is separated into an oil phase and an aqueous phase in the process of infiltrating into the paper, and is permeated and dried. I have. At that stage, set-off occurs because the undried colorant-containing phase adheres to the back side of the subsequent printed paper. The thickness of the undried colorant-containing phase depends on the particle size of the colorant particles, and if the back side of the next printing paper can be prevented from contacting the film, set-off can be prevented. Can be.

Therefore, in the present invention, the reverse phase of the colorant-containing phase contains solid particles having an average particle size larger than the colorant-containing phase on paper and having an average particle size of 20 times or more the average particle size of the colorant. By doing so, the contact is prevented. As described above, since the thickness of the colorant-containing phase depends on the particle size of the colorant particles, the colorant particle size is 20 times or more,
By using solid particles of preferably 8 to 30 μm,
Effectively, the back side of the next printing paper can be prevented from contacting the film. In addition, since the solid particles are contained in the reverse phase of the colorant particles, the adhesion of the colorant to the surface of the solid particles can be prevented, so that the colorant adheres from the surface of the solid particles to the back side of the next printing paper. No set-off occurs. If the solid particles and the colorant particles are in the same phase, the solid particle surface and the colorant surface become very compatible via the dispersion medium, so that the colorant adheres to the solid particle surface and set off. Is not an effective solution.

In the present invention, a coloring agent,
When the aqueous phase contains solid particles having an average particle diameter of 20 times or more the average particle diameter of the colorant, the above-described effects can be obtained more effectively. It is said that as a mechanism for the oil phase and the water phase to penetrate into the paper, the oil phase first penetrates into the paper, and then the water phase penetrates.
In that case, when the colorant is contained in the oil phase, the colorant-containing phase first penetrates into the inside of the paper, and the solid particles ride on it. Obtainable.

Further, in the present invention, when the average particle diameter of the solid particles is 8 to 30 μm, the above-mentioned effect can be obtained in an optimum state on an image. Even if the dispersed particle diameter of the colorant is small and the solid particles are 20 times or more than that, since the solid particle diameter itself becomes buried between paper fibers when the solid particle diameter itself becomes small, the effect is slightly reduced at 8 μm or less. I will. Further, when the solid particles have a thickness of 30 μm or more, some particles cannot pass through the master opening portion, so that although there is good set-off, white spots may occur on an image.

[0010]

Next, the present invention will be described in more detail. The solid particles used in the present invention are not particularly limited as long as they are insoluble in a dispersion medium for dispersing the particles and can maintain the solid structure. Examples thereof include polyethylene, polyester, polypropylene, polystyrene, silica, polyvinyl chloride, and polyvinylidene chloride. , Polymethyl methacrylate, calcium carbonate, aluminum oxide, and the like can be used. The amount of the solid particles to be added can be any amount at a level that does not disrupt the system of the ink itself, and is preferably 0.5 to 30% by weight based on the total amount of the ink.

The oil component used in the present invention includes mineral oil and vegetable oil. Examples of the mineral oil include petroleum solvents, liquid paraffin, spindle oil, light oil, kerosene, machine oil, gear oil, lubricating oil, and motor oil. Oils and vegetable oils include linseed oil, tall oil, corn oil, olive oil, rapeseed oil, castor oil, soybean oil, dehydrated castor oil and the like. Also, polyisobutylenes, hydrogenated polydecenes, trimethylolpropane esters, neopentyl esters, pentaerythritol esters,
Siloxanes, silicones, fluorocarbons, alkyl-substituted diphenyl ethers, phthalates,
Synthetic oils such as phosphate esters can also be used. In addition,
As the petroleum-based solvent, a mixed solvent such as a solvent such as Isopar manufactured by Exxon or AF5 solvent manufactured by Nippon Oil Co., Ltd. may be used. And these oils are used alone or 2
You may mix and use more than seeds.

As the coloring agent used in the present invention, conventionally known coloring agents can be arbitrarily used.
Pigments such as titanium oxide, azo pigments, phthalocyanine pigments, nitroso pigments, nitro pigments, vat dye pigments, mordant dye pigments, basic dye pigments, acid dye pigments, and natural dye pigments. No. These pigments, etc.
The pigment may be added alone or as a mixture of two or more kinds. The amount of the pigment added to the ink is preferably 1 to 15% by weight, and more preferably 2 to 10% by weight.

Examples of the dispersant used in the present invention include fatty acid esters of polyglycerin such as diglycerin, triglycerin, hexaglycerin and decaglycerin. Other than the fatty acid ester, examples of the sorbitan fatty acid ester include sorbitan monolaurate, sorbitan monopalmitate, sorbitan sesquioleate, and polyoxyethylene sorbitan fatty acid ester. In addition, glycerin fatty acid ester, propylene glycol fatty acid ester, pentaerythritol fatty acid ester, polyoxyethylene sorbite fatty acid ester, polyoxyethylene glycerin fatty acid ester,
Polyethylene glycol fatty acid ester, polyethylene alkyl ether, polyoxyethylene phytosterol ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene castor oil, polyoxyethylene hardened castor oil, polyoxyethylene lanolin derivative, polyoxy Examples thereof include ethylene alkylamine, polyoxyethylene fatty acid amide, polyoxyethylene alkylphenylformaldehyde condensate, and the like. In addition, alkylamine polymer compounds, aluminum chelate compounds, styrene / maleic anhydride copolymers, partial alkyl esters of polyacrylic acid, polyalkylene polyamine aliphatic polycarboxylic acids, polyethers, ester-type anionic surfactants Agents, long-chain amine salts of high molecular weight polycarboxylic acids, polyamides, phosphate surfactants, alkyl sulfocarboxylates, α-olefin sulfonates, dioctyl sulfosuccinates, alcohols and the like can be used. These dispersants may be used as needed to disperse the colorant or solid particles in the oil phase or the aqueous phase well, and may be used alone or in combination of two or more. The addition amount may be 40% or less, preferably 2 to 35% by weight of the colorant weight.

As the emulsifier, it is preferable to use a nonionic surfactant. Specifically, as the sorbitan fatty acid ester, sorbitan monolaurate, sorbitan monopalmitate, sorbitan sesquioleate, polyoxyethylene sorbitan fatty acid ester Etc. are exemplified. In addition, glycerin fatty acid ester, polyglycerin fatty acid ester, propylene glycol fatty acid ester, pentaerythritol fatty acid ester, polyoxyethylene sorbite fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyethylene glycol fatty acid ester, polyethylene alkyl ether, polyoxyethylene phytosterol ether, Polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene castor oil, polyoxyethylene hardened castor oil,
Polyoxyethylene lanolin derivative, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide,
Examples thereof include polyoxyethylene alkylphenyl formaldehyde condensates. These may be added to the ink singly or as a mixture of two or more kinds as long as the effect is not impaired, and the addition amount may be 1 to 20% by weight of the ink weight.

In the present invention, in addition to the above, a resin, a gelling agent, an antioxidant and the like can be added to the oil phase as long as the formation of the emulsion is not hindered. Also,
A water-soluble polymer, an antiseptic / fungicide, a water evaporation inhibitor, an antifreezing agent, a pH adjuster, an electrolyte, and the like can be added to the aqueous phase as long as the formation of the emulsion is not hindered. Note that the water only needs to be clean, and specifically, tap water, ion-exchanged water, distilled water, or the like may be used.

The resin added to the oil phase is a binder resin that has been conventionally added for the purpose of fixing the pigment to the printing material, dispersing the pigment, and improving the aging stability of the ink. Therefore, it is sufficient to add a conventionally added resin, specifically, rosin, polymerized rosin, hydrogenated rosin,
Rosin esters, rosin-based resins such as hydrogenated rosin esters, rosin-modified resins such as rosin-modified phenolic resins, phenolic resins, petroleum resins, alkyd resins, rubber derivatives,
Polymerized castor oil or the like may be added alone or as a mixture of two or more. The amount of addition may be 20% by weight or less, preferably 1 to 7% by weight or less of the ink weight.

The gelling agent has a role of gelling the resin contained in the oil phase to improve the storage stability and fixability of the ink. The gelling agent added to the ink of the present invention includes:
Compounds that coordinate with the resin in the oil phase are preferred. Examples of such compounds include Li, Na, K, Al, C
a, an organic acid salt containing a metal such as Co, Fe, Mn, Mg, Pb, Zn, and Zr, an organic chelate compound, a metal soap oligomer, and more specifically, a metal octylate such as aluminum octylate; Examples thereof include metal salts of naphthenic acid such as manganese acid, stearates such as zinc stearate, and organic chelate compounds such as aluminum diisopropoxide monoethyl acetoacetate. One or more of these gelling agents may be added to the oil phase,
The addition amount is 15% by weight or less, preferably 5 to 10% by weight of the resin in the oil phase.

Antioxidants added to the oil phase include dibutylhydroxytoluene, propyl gallate, butylhydroxyanisole, and the like. The addition of these additives prevents oxidation of the binder resin and the like in the oil phase, thereby reducing the viscosity of the ink. Ascent is prevented. The amount of addition is 2% by weight or less, preferably 0.1 to 1.0% by weight of the oil in the ink. The antioxidants may be used alone or in combination of two or more.

The water-soluble polymer added to the aqueous phase of the emulsion ink is added for moisturizing and thickening. Specifically, the following natural or synthetic polymers are added. Natural polymers such as starch, mannan, sodium alginate, galactan, tragacanth gum, gum arabic, pullulan, dextran, xanthan gum, glue, gelatin, collagen, casein, carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxy Semi-synthetic polymers such as methyl starch, carboxymethyl starch, and dialdehyde starch; acrylic resin derivatives such as polyacrylic acid, sodium polyacrylate, and triethanolamine polyacrylate; polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, N, N N-alkyl-substituted acrylamides such as dimethylacrylamide and N-ethylacrylamide; Ji alkylene oxide, polyvinyl methyl ether, synthetic polymers polyvinyl acetate,
And water-soluble synthetic polymers synthesized from two or more different monomers, and others. These water-soluble polymers may be used alone or in admixture of two or more, and the water contained in the ink is 25% by weight or less, preferably 0.5 to 15% by weight.
Is added.

The antiseptic / fungicide added to the aqueous phase is added to prevent the growth of bacteria and mold in the emulsion. When the emulsion is stored for a long time, the antiseptic / fungicide is usually added. is there. The amount of addition is 3% by weight or less of water contained in the ink, preferably 0.1 to 1.2% by weight. In addition, as an antiseptic and fungicide,
In addition to aromatic hydroxy compounds such as salicylic acid, phenolic acid, methyl p-oxybenzoate and ethyl p-oxybenzoate and their chlorine compounds, sorbic acid and dehydroacetic acid are used, and these may be used alone or in combination of two or more. May be used.

The water evaporation inhibitor and the antifreezing agent can be used in combination. Chemicals added for these purposes include glycols such as ethylene glycol, diethylene glycol and propylene glycol, methanol, ethanol, isopropanol, butanol, isobutanol and the like. And lower polyhydric alcohols such as glycerin and sorbitol. One or more of these chemicals may be added, and the amount of these chemicals is 15% by weight of the water in the ink.
Hereinafter, it is preferably 4 to 12% by weight.

The pH adjusters to be added to water are triethanolamine, sodium acetate, triamylamine, and the like.
H can be maintained at 6-8. If the pH of the aqueous phase is out of the above range, there is a problem that the effect is lost when a water-soluble polymer for a thickener is added.

The electrolyte added to the aqueous phase is added to enhance the stability of the emulsion. Therefore, it is preferable to add an electrolyte composed of ions having a high liquid-separation sequence effective for improving the stability of the emulsion. Anions with high syneresis are citrate ions,
Tartrate ion, sulfate ion, acetate ion, etc., and the cation having a high liquid separation order is an alkali metal ion or an alkaline earth metal ion. Therefore, at least one of the anion and the cation is used as the electrolyte added here. Preference is given to salts consisting of said ions. Therefore, as the electrolyte added here, magnesium sulfate, sodium sulfate, sodium citrate, sodium hydrogen phosphate, sodium borate, sodium acetate, and the like are preferable, and the amount of addition is 0.1 to 2% by weight of the aqueous phase. , Preferably 0.5 to 1.5% by weight
It is.

[0024] In addition to the above, the water-in-oil emulsion ink for stencil printing of the present invention is used in order to improve the separation between the printing paper and the printing drum during printing or to prevent the printing paper from rolling up. A wax can be added to the phase.

The viscosity of the aqueous phase can be further increased by adding triethanolamine, ammonia, sodium hydroxide or the like to the aqueous phase to add a water-soluble polymer. Further, by adding a rust inhibitor or a defoaming agent to the aqueous phase, it is possible to prevent the printing press from rusting or bubbling of the ink during printing. The amount of these additives may be a known product added to the stencil printing ink as needed, and the amount of addition may be about the same as that of the conventional product.

The emulsion ink of the present invention is prepared by preparing an oil phase and an aqueous phase liquid in the same manner as in the conventional emulsion ink production, stirring and dispersing each of them in a stirrer, a three-roll mill, a ball mill or the like. May be emulsified in a known emulsifying machine to form an ink.

[0027]

Next, the present invention will be described in more detail with reference to examples. The parts shown below are based on weight.

Example 1 Oil phase component Nisseki A oil (mineral oil having a viscosity of 80 mPa · S at 20 ° C.) 20.0 parts Sorbitan sesquiolate 5.0 parts HDPE powder (A) 5.0 parts Water phase component Water 52. 5 parts Ethylene glycol 10.0 parts Acrylic acid polymer 1.0 part Ammonia 0.5 parts Ethylene diol 1.0 part Carbon black 5.0 parts The oil phase components in the above proportions are mixed and dispersed by a three-roll mill. , An oil phase was obtained. Further, mixing the aqueous phase components in the above proportions,
It was dispersed in a ball mill to obtain an aqueous phase. While stirring the oil phase with an emulsifier, gradually add the aqueous phase component,
The emulsion was emulsified to obtain a W / O emulsion ink.

Using this emulsion ink, Co., Ltd.
Printing was performed with a stencil printing machine Preport VT-3820 manufactured by Ricoh Company to obtain a printed image. Before emulsification of the oil phase and the water phase, a laser type particle size distribution meter (L
A-700), the average particle diameter of the colorant and the solid particles was measured.

Example 2 Oil Phase Component Nisseki A oil (mineral oil having a viscosity of 80 mPa · S at 20 ° C.) 14.0 parts Rosin-modified polyester resin 5.0 parts Sorbitan sesquiolate 5.0 parts Aluminum chelate compound 1.0 part Carbon black 5.0 parts Water phase component Water 55.0 parts Ethylene glycol 10.0 parts Silica powder (A) 5.0 parts An ink was prepared in the same composition as in Example 1 with the above composition. The same printing and measurement as described above were performed.

Example 3 Oil phase component Nisseki A oil (mineral oil having a viscosity of 80 mPa · S at 20 ° C.) 20.0 parts Sorbitan sesquiolate 5.0 parts HDPE powder (B) 5.0 parts Water phase component Water 52. 5 parts Ethylene glycol 10.0 parts Acrylic acid polymer 1.0 part Ammonia 0.5 parts Ethylene diol 1.0 part Carbon black 5.0 parts With the above composition, an ink was prepared in the same manner as in Example 1. The same printing and measurement as in Example 1 were performed.

Example 4 Oil Phase Component Nisseki A oil (mineral oil having a viscosity of 80 mPa · S at 20 ° C.) 14.0 parts Rosin-modified polyester resin 5.0 parts Sorbitan sesquiolate 5.0 parts Aluminum chelate compound 1.0 part Carbon black 5.0 parts Water phase component Water 55.0 parts Ethylene glycol 10.0 parts Silica powder (B) 5.0 parts An ink was prepared in the same composition as in Example 1 with the above composition. The same printing and measurement as described above were performed.

Example 5 Oil Phase Component Nisseki A oil (mineral oil having a viscosity of 80 mPa · S at 20 ° C.) 20.0 parts Sorbitan sesquiolate 5.0 parts HDPE powder (C) 5.0 parts Water phase component Water 52. 0 parts Ethylene glycol 10.0 parts Acrylic acid polymer 1.0 part Ammonia 0.5 parts Ethylene diol 1.5 parts Carbon black 5.0 parts With the above composition, an ink was prepared in the same manner as in Example 1. The same printing and measurement as in Example 1 were performed.

Example 6 Oil Phase Component Nisseki A oil (mineral oil having a viscosity of 80 mPa · S at 20 ° C.) 14.0 parts Rosin-modified polyester resin 5.0 parts Sorbitan sesquiolate 5.0 parts Aluminum chelate compound 1.0 part Carbon black 5.0 parts Water phase component Water 55.0 parts Ethylene glycol 10.0 parts Silica powder (C) 5.0 parts An ink was prepared in the same composition as in Example 1 with the above composition. The same printing and measurement as described above were performed.

Comparative Example 1 Oil phase component Nisseki A oil (mineral oil having a viscosity of 80 mPa · S at 20 ° C.) 20.0 parts Sorbitan sesquiolate 5.0 parts Water phase component Water 52.5 parts Ethylene glycol 10.0 parts Acrylic Acid polymer 1.0 part Ammonia 0.5 part Ethylene diol 1.0 part Carbon black 5.0 parts Silica powder (A) 5.0 parts With the above composition, the oil phase is mixed with a stirrer and mixed with water. The phases were separated from carbon black and silica powder, and half of the aqueous phase vehicle was added to each, and dispersed separately in a ball mill. Thereafter, the aqueous phase components were mixed to obtain an aqueous phase. While stirring the oil phase with an emulsifier, the aqueous phase component was gradually added and emulsified to obtain a W / O emulsion ink. The same printing and measurement as in Example 1 were performed on this ink.

Comparative Example 2 Oil Phase Component Nisseki A oil (mineral oil having a viscosity of 80 mPa · S at 20 ° C.) 14.0 parts Rosin-modified polyester resin 5.0 parts Sorbitan sesquiolate 5.0 parts Aluminum chelate compound 1.0 part Carbon black 5.0 parts Silica powder (A) 5.0 parts Water phase component Water 55.0 parts Ethylene glycol 10.0 parts With the above composition, the aqueous phase is mixed with a stirrer, and the oil phase is carbon black. And silica powder were separated, and half of the oil phase vehicle was added to each, and the mixture was separately dispersed in a three-roll mill. Thereafter, the oil phase components were mixed to obtain an oil phase. While stirring the oil phase with an emulsifier, the aqueous phase component was gradually added and emulsified to obtain a W / O emulsion ink. The same printing and measurement as in Example 1 were performed on this ink.

Comparative Example 3 Oil Phase Component Nisseki A oil (mineral oil having a viscosity of 80 mPa · S at 20 ° C.) 14.0 parts Rosin-modified polyester resin 5.0 parts Sorbitan sesquiolate 5.0 parts Aluminum chelate compound 1.0 part Carbon black 5.0 parts Water phase component Water 55.0 parts Ethylene glycol 10.0 parts Calcium carbonate 5.0 parts An ink was prepared in the same composition as in Example 1 with the above composition.
The same printing and measurement as in Example 1 were performed.

Table 1 shows the results of Examples 1 to 6 and Comparative Examples 1 to 3. Note that the set-off shown in Table 1 is obtained by visually ranking the printed image in six stages, and the smaller the set-off amount is, the better. 1: Bad 2: Somewhat bad 3: Normal 4: Somewhat good 5: Good 6: Very good

[0039]

[Table 1]

From the results in Table 1 above, when Examples 1 to 6 and Comparative Examples 1 and 2 are compared, it can be seen that the set-off is clearly improved by putting the colorant and the solid particles in opposite phases. . Also, comparing Examples 2, 4, and 6 with Comparative Example 3,
It can be seen that even when the colorant and the solid particles are placed in opposite phases, if the solid particles are smaller than 20 times the colorant, there is no improvement effect. Next, when comparing Examples 1, 3, 5 and Examples 2, 4, and 6 with respect to the conditions described in claim 2, the oil phase is colored more than the solid phase is added to the oil phase with the colorant in the aqueous phase. It can be seen that adding solid particles to the aqueous phase with the agent has a greater effect. Further, when Examples 1, 2, and 5 are compared with Examples 3, 4, and 6 with respect to the conditions described in claim 3, a greater effect can be obtained when the average particle diameter of the solid particles is 8 μm or more. I understand. However, as in Example 6, slight white spots were observed for those having a size of more than 30 μm, although the level was not a problem on the image.
From the above results, it can be seen that an ink with improved set-off can be obtained by satisfying the conditions of the present invention.

[0041]

According to the first aspect of the present invention, the water-in-oil emulsion ink for a stencil printing machine has solid particles having an average particle diameter of at least 20 times the average particle diameter of the colorant in a phase opposite to the phase containing the colorant. , It is possible to obtain a printed matter with extremely little set-off.

The water-in-oil type emulsion ink for a stencil printing machine according to the second aspect has less set-off because the oil phase contains a colorant and the aqueous phase contains solid particles having the above average particle diameter. You can get printed matter.

Since the water-in-oil emulsion ink for a stencil printing machine according to the third aspect contains solid particles having an average particle diameter of 8 to 30 μm, it is possible to obtain a printed matter with further less set-off.

Claims (3)

[Claims] In a water-in-oil emulsion ink for a stencil printing machine in which an aqueous phase is dispersed and dispersed in an oil phase using an emulsifier, the average of the colorant is the reverse of the phase containing the colorant. A water-in-oil emulsion ink for a stencil printing press, comprising solid particles having an average particle diameter of 20 times or more the particle diameter. 2. The stencil printing machine according to claim 1, wherein the oil phase contains a colorant and the aqueous phase contains solid particles having an average particle diameter of 20 times or more the average particle diameter of the colorant. Water-in-oil emulsion ink for use. 3. The water-in-oil emulsion ink for stencil printing press according to claim 1, wherein the average particle diameter of the solid particles is 8 to 30 μm.