JP2005325207A - Emulsion ink for stencil printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an emulsion ink for stencil printing which contains a soybean oil fatty acid alkyd resin and a vegetable oil; is environmentally friendly, safe and stable; and can significantly improve feed roller-staining by printing. <P>SOLUTION: The emulsion ink for stencil printing comprises 10-90 mass% of an oil phase and 90-10 mass% of a water phase, wherein the oil phase contains a vegetable oil and a soybean oil fatty acid alkyd resin. Preferred aspects include an aspect in which the vegetable oil is at least any of a soybean oil, an esterified vegetable oil or a regenerated esterified vegetable oil; an aspect in which the regenerated esterified vegetable oil is an esterified vegetable oil obtained by regenerating and esterifying a waste edible vegetable oil; and an aspect in which the content of the soybean oil fatty acid alkyd resin in the emulsion ink for stencil printing is 1-7 mass%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an emulsion ink for stencil printing, which contains soybean oil fatty acid alkyd resin and vegetable oil, is environmentally friendly, safe and excellent in stability, and can greatly improve feed roller stain due to printing.

  As is well known, a stencil printing method uses a stencil printing paper (stencil) having a perforated portion, and moves the ink from one side of the stencil to the other side through the perforated portion of the stencil, so that the paper This is a method for printing on the surface of a substrate. In this stencil printing method, a water-in-oil type (W / O type) containing a volatile solvent, a non-volatile solvent, a resin, a colorant, a surfactant, water, an antifreezing agent, an electrolyte, and an antiseptic is conventionally used. ) Emulsion ink.

In double-sided printing by a stencil printing machine, the ink on the image of the first printing (printing on the front side of the paper) is transferred to the paper feeder of the printing machine during the second printing (printing on the back side of the paper). As the printing progresses, so-called feed roller smearing occurs that shifts from the feed roller onto the image of the first printing and contaminates the image. (Hereafter referred to as feed roller dirt)
Especially in stencil printing machines, the drying of the ink relies only on the permeability of the ink to the paper, so compared to other printing systems, the problem of contamination of the feed roller is serious because the drying is slow and the ink film on the image is weak. is there.

  At present, the necessity of double-sided printing is increasing to reduce the amount of paper used from the viewpoint of environmental protection, and therefore, stencil printing presses are increasingly required to improve the contamination of the feed roller. In order to improve the contamination of the feed roller, the penetration rate of the pigment into the paper has been improved by improving the pigment dispersion and the fixability of the pigment to the paper has been improved by the addition of varnish, but it is not improved sufficiently.

In recent years, emulsion inks for stencil printing to which vegetable oil is added in consideration of the environment have been used. However, since vegetable oils are semi-drying oils or drying oils having an iodine value of more than 100, when used in emulsion inks for stencil printing, oxidation of unsaturated acids occurs when left on a printing machine for a long time, and the ink There is a problem that it solidifies and causes clogging of the screen of the printing press and lacks stability. As a countermeasure, for example, a method has been proposed in which an antioxidant is added to emulsion ink for stencil printing to prevent oxidation and improve stability (see Patent Documents 1 to 3).
Moreover, the emulsion ink for stencil printing using vegetable oil has the problem that the feed roller stain | pollution | contamination will arise by printing. Furthermore, the remaining oil (waste edible oil) used in the production of food and drink is reused in the production of samples, recycled as fuel, processed into soap by recycling, The amount of edible oil production has been increasing year by year, it has not been fully processed, and its effective use has not been achieved.

JP 2002-212483 A JP 2002-201396 A JP 2002-212481 A

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, an object of the present invention is to provide an emulsion ink for stencil printing which contains soybean oil fatty acid alkyd resin and vegetable oil, is excellent in environmental properties, and can greatly improve the feed roller stain due to printing.

  As a result of intensive studies by the inventor in order to solve the above problems, the following knowledge has been obtained. That is, the emulsion ink for stencil printing containing 10 to 90% by mass of the oil phase and 90 to 10% by mass of the aqueous phase contains 10 to 90% by mass of the oil phase and 90 to 10% by mass of the aqueous phase. It is a knowledge that by containing soybean oil fatty acid alkyd resin, it is excellent in environmental properties and can greatly improve the feed roller stain due to printing.

The present invention is based on the above knowledge of the present inventor, and means for solving the above problems are as follows. That is,
<1> An emulsion ink for stencil printing comprising 10 to 90% by mass of an oil phase and 90 to 10% by mass of an aqueous phase, wherein the oil phase contains vegetable oil and soybean oil fatty acid alkyd resin. In the emulsion ink for stencil printing of the present invention, by mixing and using vegetable oil and soybean oil fatty acid alkyd resin, the feed roller stain due to printing can be greatly improved compared to ink containing only vegetable oil, and more vegetable oil is used. By doing so, it became possible to obtain an ink with better safety. Furthermore, if the total of soybean oil and soybean oil fatty acid alkyd resin is 6% by mass or more of the total ink, it is preferable because it satisfies the certification of soybean oil ink of the American Soybean Association.

  <2> The emulsion ink for stencil printing according to <1>, wherein the vegetable oil is at least one of soybean oil, esterified vegetable oil, and regenerated esterified vegetable oil. The emulsion ink for stencil printing according to <2> is stable because it is harder to oxidize than vegetable oil not esterified by using soybean oil, esterified vegetable oil, or regenerated esterified vegetable oil as vegetable oil. It has become possible to obtain emulsion inks for stencil printing that have excellent on-machine stability without causing clogging, and also contain soybean oil fatty acid alkyd resin, so that printing can be performed compared to inks containing only esterified vegetable oil. It became possible to obtain emulsion inks for stencil printing that greatly improved the contamination of the feed roller. In addition, the inclusion of esterified vegetable oil increases the yield value of the ink and makes it possible to obtain an emulsion ink for stencil printing with excellent printing characteristics. Further, when the esterified vegetable oil is derived from soybean oil, the total amount of the esterified vegetable oil and soybean oil fatty acid alkyd resin is 6% by mass or more of the total, satisfying the certification as a soybean oil ink of the American Soybean Association. Therefore, it is preferable.

  <3> The emulsion ink for stencil printing according to <2>, wherein the regenerated esterified vegetable oil is obtained by esterifying a regenerated vegetable oil obtained by regenerating waste food vegetable oil. In the emulsion ink for stencil printing according to <3>, further environmental measures have been achieved from the point of reusing resources by using regenerated plant oil obtained by esterifying regenerated waste vegetable oil. An emulsion ink for stencil printing can be obtained. Furthermore, by using the emulsion ink for stencil printing, which was obtained by reprocessing waste edible vegetable oil, it has become possible to reuse waste edible oil, which has been increasing year by year, and improved recyclability.

  <4> The emulsion ink for stencil printing according to any one of <1> to <3>, wherein the content of the soybean oil fatty acid alkyd resin in the emulsion ink for stencil printing is 1 to 7% by mass. In the emulsion ink for stencil printing according to <4>, stencil printing that significantly improves the feed roller stain particularly by containing 1 to 7% by mass of soybean oil fatty acid alkyd resin in the emulsion ink for stencil printing. It became possible to obtain an emulsion ink. If the soybean oil fatty acid alkyd resin is contained in an amount of 7% by mass or more, no further effect is observed, and the on-machine stability tends to deteriorate, so 1-7% by mass in the ink is preferable.

  According to the present invention, emulsion inks for stencil printing that can solve various problems in the past, contain soybean oil fatty acid alkyd resin and vegetable oil, are environmentally friendly, safe and stable, and greatly improve feed roller stain due to printing. Can provide.

  The emulsion ink for stencil printing of the present invention comprises 10 to 90% by mass of an oil phase and 90 to 10% by mass of an aqueous phase, and contains vegetable oil and soybean oil fatty acid alkyd resin in the oil phase, and contains mineral oil and coloring. It contains a colorant, a colorant dispersant, and, if necessary, other components.

In this case, the emulsion ink for stencil printing contains 10 to 90% by mass of an oil phase and 90 to 10% by mass of an aqueous phase, preferably 20 to 50% by mass of an oil phase and 50 to 80% by mass of an aqueous phase.
If the mixing ratio of the oil phase is less than 10% by mass, it may not be possible to take the form of a W / O type emulsion. If it exceeds 90% by mass, the physical properties of the W / O type emulsion can be obtained. May be insufficient.

<Oil phase>
-Soybean oil fatty acid alkyd resin-
The soybean oil fatty acid alkyd resin contains soybean oil, polybasic acid, and polyhydric alcohol as fats and oils. In addition to soybean oil, a part of drying oil such as linseed oil and kiri oil having an iodine value of 80 or less may be used as the oil. Further, if necessary, non-drying oil, semi-drying oil or fatty acids having an iodine value of 80 or less, such as coconut oil, palm oil, olive oil, castor oil, rice bran oil, and cottonseed oil, can also be used.
As the polybasic acid, either a saturated polybasic acid or an unsaturated polybasic acid can be used. Examples of the saturated polybasic acid include phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, tetrahydrophthalic acid and the like. Examples of the unsaturated polybasic acid include maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic anhydride, and the like.
Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, glycerin, trimethylolpropane, neopentyl glycol, diglycerin, triglycerin, and pentaerythritol. Examples include slits, dipentaery slits, mannits, and sorbits.
The oil length of the soybean oil fatty acid alkyd resin is indicated by mass% in the resin when the fatty acid in the fat and oil is present in triglyceride, from the viewpoint of improving dispersion stability and clogging of the copper plate screen due to film formation. The oil length is preferably 60 to 90% by mass. The iodine value of the soybean oil fatty acid alkyd resin is preferably 80 or less.

The weight average molecular weight of the soybean oil fatty acid alkyd resin is preferably 30,000 or less, and more preferably 10,000 or less. If the weight average molecular weight of the soybean oil fatty acid alkyd resin is too low, the effect on fixability may be reduced, and if the weight average molecular weight is too high, the plastic viscosity of the ink increases and ink leaks from the rear end of the drum. There may be a problem in printability such as.
1-7 mass% is preferable with respect to the total mass of the said emulsion ink for stencil printing, and, as for the addition amount of the said soybean oil fatty acid alkyd resin, 3-7 mass% is more preferable. If the addition amount of the soybean oil fatty acid alkyd resin is too small, the effect on the fixing property may be reduced, and if the addition amount of the soybean oil fatty acid alkyd resin is too large, the plastic viscosity of the ink increases, Problems may arise in printability such as ink leaking from the edges.

  In addition to the soybean oil fatty acid alkyd resin, the oil phase of the emulsion ink for stencil printing of the present invention may contain other resins as long as the objects and effects of the present invention are not impaired. There is no restriction | limiting in particular as this other resin, According to the objective, it can select suitably according to the objective, for example, rosin; Polymerized rosin, hydrogenated rosin, rosin ester, rosin polyester resin, hydrogenated rosin ester Rosin resin such as rosin modified rosin modified alkyd resin, rosin modified maleic resin, rosin modified resin such as rosin modified phenol resin, etc .; maleic resin; phenol resin; petroleum resin; rubber derivative resin such as cyclized rubber; terpene resin; Castor oil and the like can be mentioned, and these may be used alone or in combination of two or more.

-Vegetable oil-
As the vegetable oil, at least one of soybean oil, esterified vegetable oil, and regenerated esterified vegetable oil is used.
Examples of the vegetable oil used in the esterified vegetable oil or the regenerated esterified vegetable oil include soybean oil, rapeseed oil, corn oil, sunflower oil, safflower oil, sesame oil, castor oil, dehydrated castor oil, camellia oil, olive oil, palm oil, Rice oil, cottonseed oil, palm oil, linseed oil, palm kernel oil, tung oil, camelia oil, grape seed oil, sweet almond oil, pistachio nut oil, jojoba oil, macadamian nut oil, meadowweed oil, etc. Among these, soybean oil, rapeseed oil, corn oil, and safflower oil are particularly preferable. These may be used individually by 1 type and may use 2 or more types together.
Examples of the esterified vegetable oil include those obtained by esterifying the vegetable oil. Examples of the ester include methyl ester, ethyl ester, and butyl ester.
Examples of the regenerated esterified vegetable oil include those obtained by esterifying a vegetable oil that is recovered as waste cooking oil and regenerated using the vegetable oil. Examples of the ester include methyl ester, ethyl ester, and butyl ester. The waste cooking oil is not particularly limited and can be appropriately selected according to the purpose.For example, those obtained by collecting vegetable oil used for the production of tempura at restaurants, school lunches, prepared dishes, etc. In addition to these, any material that can be regenerated with vegetable oil after use is applicable. These may be used individually by 1 type and may use 2 or more types together.

1-40 mass% is preferable and, as for the addition amount in the emulsion ink for stencil printing of the said vegetable oil, 1-20 mass% is more preferable. In particular, when the vegetable oil is derived from soybean oil and 6% by mass or more of the whole is soybean oil, it is preferable because it satisfies the approval of soybean oil ink of the American Soybean Association.
When the added amount of the vegetable oil is less than 1% by mass, the merit in safety and the environment may be poor, and when it exceeds 40% by mass, it is difficult to control physical properties by other components. Sometimes.

  In addition to the soybean oil fatty acid alkyd resin and vegetable oil, the oil phase contains mineral oil and, if necessary, other components such as a colorant, a colorant dispersant, an extender pigment, and an emulsifier.

-Mineral oil-
The mineral oil is not particularly limited and can be appropriately selected according to the purpose. For example, paraffinic oil, naphthenic oil, petroleum solvent, spindle oil, liquid paraffin, light oil, kerosene, machine oil, gear Oils, lubricating oils, motor oils and the like can be mentioned. Among these, paraffinic oils, naphthenic oils, and petroleum solvents are particularly preferable.
Commercially available products can be used as the paraffinic oil. For example, Samics GA series manufactured by Sanwa Kasei Kogyo Co., Ltd., Gargo Oil Arctic Series manufactured by Mobil Oil Co., Ltd., and Nippon Oil Super Oil Series manufactured by Nippon Oil Co., Ltd. And Diana Process Oil, Diana Fresia series manufactured by Idemitsu Kosan Co., Ltd.
The naphthenic oil has a naphthene component carbon content (CN) of 30% or more by ring analysis, an aromatic component carbon content (CA) of 20% or less, and a paraffin component carbon content. A quantity (CP) of 55% or less is suitable, for example, Gargo Oil Arctic Oil 155 and 300ID manufactured by Mobil Oil, Gargo Oil Arctic Oil Light, Gargo Oil Arctic Oil C Heavy; Idemitsu Kosan Co., Ltd. The company's Diana Process Oil, Diana Fresia Series; Nippon San Oil Co., Ltd.
Commercially available products may be used as the petroleum solvent, and examples include Isopar series and Exol manufactured by Exxon Chemical; AF Solvent Series manufactured by Nippon Oil Corporation.

When considering the stability of the ink, these mineral oils preferably use those having a polycyclic aromatic component that is an aromatic hydrocarbon containing three or more condensed aromatic rings of less than 3% by mass. . Further, the mutagenicity index MI is less than 1.0, the aroma content (% C _A ) is 20 to 55%, the aniline point is 100 ° C. or less, and benzo [a] anthracene, benzo [ b] The content of polycyclic aromatics such as fluoranthene, benzo [j] fluoranthene, benzo [k] fluoranthene, benzo [a] pyrene, dibenzo [a, j] acridine is 10 ppm or less, and the total content is 50 ppm or less.
If necessary, highly safe aroma oil (for example, JP-A-11-80640) can be used.

There is no restriction | limiting in particular in the addition amount in the emulsion ink for stencil printing of the said mineral oil, According to the objective, it can select suitably, 1-40 mass% is preferable, and 5-20 mass% is more preferable.
If the amount of the mineral oil added is less than 1% by mass, the rub stain immediately after printing may be somewhat deteriorated, and if it exceeds 40% by mass, it will be difficult to control physical properties by other components. Sometimes.

-Other ingredients-
As the colorant, known pigments and disperse dyes of various colors can be used, for example, carbon blacks such as acetylene black, channel black and furnace black; metal powders such as aluminum powder and bronze powder; Inorganic pigments such as yellow lead, ultramarine, chromium oxide and titanium oxide; azo pigments such as insoluble azo pigments, azo lake pigments and condensed azo pigments; phthalocyanine pigments such as metal-free phthalocyanine pigments and copper phthalocyanine pigments; anthraquinone dyes; Condensed polycyclic pigments such as quinacridone dyes, isoindolinone dyes, isoindoline dyes, dioxazine dyes, selenium dyes, perylene dyes, perinone dyes, thioindigo dyes, quinophthalone dyes, metal complexes; Organic pigments such as acid or basic dye lakes; diazo dyes, a Oil-soluble dyes such as Torakinon dyes; fluorescent pigment, and the like. Among these, carbon black, azo lake pigments, such as phthalocyanine pigments are particularly preferable. These may be used individually by 1 type and may use 2 or more types together.

  As the fluorescent pigment, a so-called synthetic resin solid solution obtained by dissolving or dyeing a fluorescent dye that develops various hues after bulk polymerization of a synthetic resin or by pulverizing and refining the obtained colored bulk resin Examples of synthetic resins that carry dyes include melamine resins, urea resins, sulfonamide resins, alkyd resins, and polyvinyl chloride resins.

  When carbon black as the colorant is added to the oil phase, commercially available products can be used as acidic carbon black having a pH of less than 5, for example, MA-100, MA-7, MA-77, MA -11, # 40, # 44 (all manufactured by Mitsubishi Chemical Corporation), Raven1100, Raven1080, Raven1255, Raven760, Raven410 (all manufactured by Colombian Carbon Co., Ltd.), and the like.

The average particle diameter of the colorant is preferably 0.01 to 1 μm, and more preferably 0.02 to 0.5 μm.
There is no restriction | limiting in particular in the addition amount in the emulsion ink for stencil printing of the said coloring agent, According to the objective, it can select suitably, Usually, 2-15 mass% is preferable.

  The emulsifier is not particularly limited as long as it can form a water-in-oil emulsion, and can be appropriately selected according to the purpose. For the purpose of stabilizing the emulsion, an electrolyte or the like is added to the aqueous phase. For this, a nonionic surfactant is preferred because it can avoid electrical side effects. Examples of the nonionic surfactant include sorbitan fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, propylene glycol fatty acid ester, pentaerythritol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbite fatty acid ester, polyoxy Ethylene glycerin fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene phytosterol ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, poly Oxyethylene lanolin derivatives, polyoxyethylene alkyl amines Emissions, polyoxyethylene fatty acid amides, polyoxyethylene alkylphenyl formaldehyde condensates, and the like, which may be used alone or in combination of two or more thereof.

  There is no restriction | limiting in particular in the addition amount in the emulsion ink for stencil printing of the said emulsifier, According to the objective, it can select suitably, 1-8 mass% is preferable, and 2-5.5 mass% is more preferable.

  The colorant dispersant is not particularly limited as long as it does not inhibit the formation of an emulsion, and can be appropriately selected according to the purpose. For example, the nonionic surfactant for an emulsifier, an alkylamine polymer. Compound, aluminum chelate compound, styrene-maleic anhydride copolymer, partial alkyl ester of polyacrylic acid, polyalkylene polyamine, aliphatic polycarboxylic acid, polyether, ester type anionic surfactant, high molecular weight polycarboxylic acid Long-chain amine salts, polyamide compounds, phosphate ester surfactants, alkyl sulfocarboxylates, α-olefin sulfonates, dioctyl sulfosuccinates, polyethyleneimines, alkylolamine salts, alkyd resins and other insoluble colorants Inhibits the storage stability of resins and inks with dispersibility If no range ionic surfactants, amphoteric surfactants may also be used. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular in the addition amount of the said coloring agent dispersing agent, According to the objective, it can select suitably, 40 mass% or less of the total mass of a coloring agent is preferable, and 2-35 mass% is more preferable.

  The gelling agent has a role of improving the storage stability, fixability, fluidity, etc. of the ink by gelling the resin contained in the oil phase, and is preferably a compound that coordinates with the resin in the oil phase. . Examples of the gelling agent include organic acid salts containing organic metals such as Li, Na, K, Al, Ca, Co, Fe, Mn, Mg, Pb, Zn, and Zr, organic chelate compounds, and metal soap oligomers. Can be mentioned. Specifically, octylic acid metal salts such as aluminum octylate, naphthenic acid metal salts such as manganese naphthenate, stearates such as zinc stearate, organic chelate compounds such as aluminum diisopropoxide monoethyl acetoacetate, etc. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular in the addition amount of the said gelatinizer, According to the objective, it can select suitably, 15 mass% or less is preferable with respect to the total amount of resin in an oil phase, and 5-10 mass% is more preferable.

The extender pigment is not particularly limited, and can be added to the ink in the oil phase, the water phase, or both phases for preventing bleeding and adjusting the viscosity, and either inorganic fine particles or organic fine particles are preferable. Examples of the inorganic fine particles include clay, silica, talc, clay, calcium carbonate, barium sulfate, titanium oxide, alumina white, diatomaceous earth, kaolin, mica, and aluminum hydroxide. Examples of the organic fine particles include polyacrylate resin, polyurethane resin, polyester resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polysiloxane resin, phenol resin, epoxy resin, or these A copolymer, and the like.
There is no restriction | limiting in particular in the addition amount in the emulsion ink for stencil printing of the said extender, According to the objective, it can select suitably, 0.1-50 mass% is preferable, and 1-5 mass% is more preferable.

There is no restriction | limiting in particular as said antioxidant, Although it can select and use suitably from well-known things, For example, dibutylhydroxytoluene, propyl gallate, butylhydroxyanisole, etc. are mentioned, These are 1 type. You may use individually and may use 2 or more types together.
Addition of the antioxidant prevents oxidation of the binder resin or the like in the oil phase, thereby preventing an increase in ink viscosity.
There is no restriction | limiting in particular in the addition amount of the said antioxidant, According to the objective, it can select suitably, 2 mass% or less is preferable with respect to the total amount of the oil phase in ink, 0.1-1.0 mass% Is more preferable.

<Water phase>
The aqueous phase is water, electrolyte, water-soluble polymer compound, O / W resin emulsion, antiseptic / antifungal agent, water evaporation inhibitor or antifreeze agent, pH adjuster, etc. as long as it does not interfere with the formation of the emulsion. And further contains other components as necessary.

  If it is clean, there will be no restriction | limiting in particular if it is clean, According to the objective, it can select suitably, For example, a tap water, ion-exchange water, distilled water etc. can be used.

The electrolyte is added to increase the stability of the emulsion, and it is preferable to add an electrolyte composed of ions having a high liquid separation permutation effective for improving the stability of the emulsion. Anions having a high liquid separation permutation are citrate ions, tartaric acid ions, sulfate ions, acetate ions, and the like. Cations having a high liquid separation permutation are alkali metal ions and alkaline earth metal ions. The electrolyte added here is preferably a salt in which at least one of an anion and a cation is composed of the ion. Accordingly, as the electrolyte, for example, magnesium sulfate, sodium sulfate, sodium citrate, sodium hydrogen phosphate, sodium borate, sodium acetate, and the like are suitable. These may be used individually by 1 type and may use 2 or more types together.
There is no restriction | limiting in particular in the addition amount of the said electrolyte, According to the objective, it can select suitably, 0.1-2 mass% of a water phase is preferable, and 0.5-1.5 mass% is more preferable.

The water-soluble polymer compound is added for humidification and thickening, and examples thereof include natural polymer compounds, semi-synthetic polymer compounds, and synthetic polymer compounds. These may be used individually by 1 type and may use 2 or more types together.
Examples of the natural polymer compound include starch, mannan, sodium alginate, galactan, tragacanth gum, gum arabic, pullulan, dextran, xanthan gum, glue, gelatin, collagen, casein and the like.
Examples of the semi-synthetic polymer compound include carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxymethyl starch, carboxymethyl starch, and dialdehyde starch.
Examples of the synthetic polymer compound include acrylic acid resin derivatives such as polyacrylic acid, sodium polyacrylate, and triethanolamine polyacrylate; synthetic polymers such as polyvinyl alcohol, polyacrylamide, polyethylene oxide, and polyvinyl methyl ether. Is mentioned.
The addition amount of the water-soluble polymer compound is not particularly limited and may be appropriately selected depending on the purpose. The amount of water contained in the ink is preferably 25% by mass or less, more preferably 0.5 to 15% by mass. .

There is no restriction | limiting in particular as said oil-in-water resin emulsion, Although it can select suitably from well-known things and can use, a synthetic polymer compound or a natural polymer compound may be sufficient. Examples of the synthetic polymer compound include polyvinyl acetate resin, acrylic ester resin, methacrylic ester resin, polyvinyl chloride resin, ethylene-vinyl acetate copolymer, vinyl acetate-acrylic ester copolymer, styrene- Examples thereof include acrylic acid ester copolymers, vinylidene chloride-acrylic acid ester copolymers, vinyl chloride-vinyl acetate copolymers, and urethane resins. Examples of the natural polymer compound include polymer compounds that can be added to an oil phase commonly used in emulsion inks for stencil printing. These may be used individually by 1 type and may use 2 or more types together.
Further, the dispersion method of the oil-in-water resin emulsion is not particularly limited, and a dispersant, a protective colloid, and a surfactant may be added, or may be synthesized by soap-free emulsion polymerization. There is no restriction | limiting in particular in the minimum film forming temperature of the said oil-in-water resin emulsion, According to the objective, it can select suitably, 40 degrees C or less is preferable.

The antiseptic / antifungal agent is added to prevent bacteria and fungi from growing in the emulsion, and is effective when the emulsion is stored for a long period of time. The antiseptic / antifungal agent is not particularly limited and may be appropriately selected from known ones. Examples include salicylic acid, phenols, methyl p-oxybenzoate, ethyl p-oxybenzoate, and the like. Aromatic hydroxy compounds or chlorinated compounds thereof, sorbic acid, dehydroacetic acid and the like, and these may be used alone or in combination of two or more.
The addition amount of the antiseptic / antifungal agent is not particularly limited and may be appropriately selected depending on the purpose. It is preferably 3% by mass or less based on the total mass of water contained in the ink, More preferably, it is 2% by mass.

The water evaporation inhibitor or antifreeze agent is not particularly limited and may be appropriately selected from known ones. Examples thereof include lower saturated monohydric alcohols, glycols and polyhydric alcohols. . These may be used individually by 1 type and may use 2 or more types together.
Examples of the lower saturated monohydric alcohol include methanol, ethanol, isopropanol, butanol, isobutanol and the like. Examples of the glycol include ethylene glycol, diethylene glycol, and propylene glycol. Examples of the polyhydric alcohol include sorbitol.
The addition amount of the water evaporation inhibitor or antifreeze agent is not particularly limited and may be appropriately selected depending on the purpose. It is preferably 15% by mass or less based on the total mass of water in the ink. The mass% is more preferable.

  There is no restriction | limiting in particular as said pH adjuster, Although it can select and use suitably from well-known things, For example, a triethanolamine, sodium acetate, a triamylamine etc. are mentioned suitably. Furthermore, if necessary, these pH adjusters can be added to maintain the pH of the aqueous phase at 6-8. When the pH of the aqueous phase deviates from the above range, the effect may be impaired when the water-soluble polymer for thickener is added.

  In the emulsion ink for stencil printing of the present invention, wax can be added to the oil phase in order to improve separation between the printing paper and the printing drum during printing, or to prevent the printing paper from rolling up. Further, triethanolamine, sodium hydroxide or the like can be added to the aqueous phase to further increase the viscosity by adding a water-soluble polymer compound. Furthermore, a rust preventive agent or an antifoaming agent can be added to the water phase to prevent the printing press from being rusted by ink or causing ink to foam. These additives may be appropriately added as necessary from known additives added to the emulsion ink for stencil printing, and the addition amount thereof may be the same as that of a conventional product.

  The method for producing the emulsion ink for stencil printing of the present invention is not particularly limited and can be appropriately selected from known methods according to the purpose. For example, the oil phase and the aqueous phase liquid are previously prepared by a conventional method. It can be prepared by separately preparing, adding an aqueous phase to the oil phase, and emulsifying in a known emulsifier such as a disper mixer, a homomixer, or a high-pressure homogenizer. Specifically, an oil in which additives such as a colorant, an emulsifier and a resin to be added as needed are well dispersed in a three-roll mill is prepared by a conventional method, and an antiseptic / antifungal agent or a water-soluble What is necessary is just to gradually add and emulsify the aqueous solution to which the molecular compound etc. are added as needed.

In the emulsion ink for stencil printing of the present invention, the viscosity at a shear rate of 20 sec ⁻¹ is preferably 3 to 40 Pa · s, more preferably 10 to 30 Pa · s.
As described above, the emulsion ink for stencil printing of the present invention has no problems of clogging after being left standing or delay of image start-up in printing, and can greatly improve the contamination of the feed roller during double-sided printing. It is suitably used for stencil printing by a stencil printer.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example 1)
-Preparation of emulsion ink for stencil printing-
Phthalocyanine blue (manufactured by Toyo Ink Manufacturing Co., Ltd.) 4.5 mass%, carbon black (manufactured by Columbia Carbon Co., Ltd., Raven 1100) 0.5 mass%, aluminum chelate as a pigment dispersant (manufactured by Ajinomoto Fine Techno Co., Ltd.) 0 0.5% by mass, Samic GA 1046 (manufactured by Sanwa Kasei Kogyo Co., Ltd.) as a mineral oil, 6.0% by mass, and 3.0% by mass of soybean oil as a vegetable oil are mixed with three rolls to disperse the pigment The body was prepared. To this pigment dispersion, 8.7% by mass of Samic GA 1046 (manufactured by Sanwa Kasei Kogyo Co., Ltd.) as mineral oil, 3% by mass of soybean oil fatty acid alkyd resin, and 4.0% by mass of sorbitan sesquiolate were added and mixed. To prepare an oil phase.
On the other hand, 10.0% by mass of ethylene glycol, 0.1% by mass of methyl p-oxybenzoate, 1.0% by mass of magnesium sulfate, and 58.7% by mass of tap water were mixed to prepare an aqueous phase.

  Next, the water phase was gradually added to the oil phase and emulsified with a disper mixer to prepare an emulsion ink for stencil printing.

(Example 2)
-Preparation of emulsion ink for stencil printing-
In Example 1, 10.7% by mass of Samic GA 1046 (Sanwa Kasei Kogyo Co., Ltd.) as mineral oil, 4.0% by mass of soybean methyl ester as esterified vegetable oil, and soybean oil fatty acid alkyd resin An emulsion ink for stencil printing was prepared in the same manner as in Example 1 except that 6.0% by mass was added.

(Example 3)
-Preparation of emulsion ink for stencil printing-
In Example 1, 9.7% by mass of gargoyle arctic light (manufactured by ExxonMobil) as mineral oil, 4.0% by mass of soybean butyl ester as regenerated esterified vegetable oil, and 7.% of soybean oil fatty acid alkyd resin. An emulsion ink for stencil printing was prepared in the same manner as in Example 1 except that 0% by mass was added.

(Comparative Example 1)
-Preparation of emulsion ink for stencil printing-
In Example 1, an emulsion ink for stencil printing was prepared in the same manner as in Example 1 except that 6.0% by mass of soybean oil was added and no soybean oil fatty acid alkyd resin was added.

(Comparative Example 2)
-Preparation of emulsion ink for stencil printing-
In Example 1, an emulsion ink for stencil printing was prepared in the same manner as in Example 1 except that 6.0% by mass of soybean methyl ester as an esterified vegetable oil was added and no soybean oil fatty acid alkyd resin was added.

(Comparative Example 3)
-Preparation of emulsion ink for stencil printing-
In Example 1, Gargoyle Arctic Light (manufactured by ExxonMobil) as mineral oil was added in an amount of 12.7% by mass and soybean oil fatty acid alkyd resin was added in an amount of 8.0% by mass in the same manner as in Example 1. Thus, an emulsion ink for stencil printing was prepared.

  Next, performance evaluation was performed as follows about the emulsion ink for stencil printing of Examples 1-3 and Comparative Examples 1-3. The results are shown in Table 1.

<Standing stability on board>
Each emulsion ink for stencil printing was thinly coated on a glass plate with a bar coder, and the drying property of the ink was evaluated according to the following criteria.
〔Evaluation criteria〕
X: The ink hardened by standing within one month.
(Triangle | delta): Ink solidified by leaving within three months.
○: The ink was hardened by leaving within 6 months.
A: The ink did not dry.

<Dirty feed roller>
About each emulsion ink for stencil printing, using a stencil printing machine (JP5500, manufactured by Ricoh Co., Ltd.), after the surface was printed, the stain on the feed roller when the back surface was printed 2 minutes later was evaluated according to the following criteria.
〔Evaluation criteria〕
X: There is a large amount of dirt.
Δ: There is a little dirt.
○: There is no dirt.
A: There is no dirt.

表１の結果から、大豆油脂肪酸アルキド樹脂を含有せず、大豆油のみを含有する比較例１は、機上放置安定性に劣り、フィードローラー汚れが大量に生じてしまうことが認められる。また、大豆油脂肪酸アルキド樹脂を含有せず、エステル化植物油のみを含有する比較例２は、フィードローラー汚れが大量に生じることが認められた。また、植物油を含有せず、大豆油脂肪酸アルキド樹脂を含有する比較例３は、機上放置安定性がやや劣ることが認められる。
これに対し、実施例１〜３は、機上放置安定性に優れ、フィードローラー汚れが改善できることが認められる。

From the results shown in Table 1, it can be seen that Comparative Example 1 containing no soybean oil fatty acid alkyd resin and containing only soybean oil is inferior in on-machine stability, and a large amount of feed roller contamination occurs. Moreover, it was recognized that the comparative example 2 which does not contain soybean oil fatty acid alkyd resin and contains only esterified vegetable oil produces a large amount of feed roller soiling. Moreover, it is recognized that Comparative Example 3 which does not contain vegetable oil and contains soybean oil fatty acid alkyd resin is slightly inferior in the on-machine stability.
On the other hand, it is recognized that Examples 1 to 3 have excellent on-machine stability and can improve feed roller contamination.

The emulsion ink for stencil printing of the present invention contains soybean oil fatty acid alkyd resin and vegetable oil, is environmentally friendly and safe, stable over a long period of time, can greatly improve the feed roller stain due to printing, It is suitably used for stencil printing by a stencil printing machine, particularly double-sided printing.

Claims (4)

  An emulsion ink for stencil printing comprising 10 to 90% by mass of an oil phase and 90 to 10% by mass of an aqueous phase, wherein the oil phase contains vegetable oil and soybean oil fatty acid alkyd resin.   The emulsion ink for stencil printing according to claim 1, wherein the vegetable oil is at least one of soybean oil, esterified vegetable oil, and regenerated esterified vegetable oil.   The emulsion ink for stencil printing according to claim 2, wherein the regenerated esterified vegetable oil is obtained by esterifying regenerated vegetable oil obtained by regenerating waste food vegetable oil. The emulsion ink for stencil printing according to any one of claims 1 to 3, wherein the content of the soybean oil fatty acid alkyd resin in the emulsion ink for stencil printing is 1 to 7% by mass.