JP2001247805A - Stencil printing ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the dispersibility of a smectite-containing stencil printing ink and to stabilize it. SOLUTION: Into the stencil printing emulsion ink or stencil printing oil based ink which contains smectite, a carboxylic acid salt of a polyaminoamide or a salt of a long chain polyaminoamide and a polar acid ester is incorporated as the polyaminoamide dispersing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing ink, and more particularly to a stencil printing ink containing smectite.

[0002]

2. Description of the Related Art In a stencil printing method, printing is performed on a surface of a printing material such as paper by moving ink from one side of a stencil sheet to the other side through a perforated portion of the stencil sheet. .

In general, it is desired that stencil printing inks have good permeability to stencil paper, have appropriate fluidity, have good leveling after printing, and have good drying properties. In particular, the ink used in the stencil printing method, in which the drum is an open system, needs to have an appropriate hardness so as not to cause dripping of the ink, and an appropriate softness in order to allow the ink to penetrate the printing material quickly. is necessary. Therefore, it is extremely important to adjust the fluidity of the ink.

Conventionally, as one method of adjusting the fluidity of ink, a flow modifier has been generally added. In stencil printing inks, bentonite containing montmorillonite as a main component, hectane Smectite clay minerals such as light, hyderite and saponite are often used. For example, Japanese Patent Publication No. 54-23601 describes an ink in which a thickener such as organic bentonite is contained, and the emulsion ink for stencil printing is substantially hardened to improve the printing finish. JP-A-6-33007 proposes an emulsion ink containing a surfactant-encapsulated organically modified montmorillonite which is excellent in emulsion ink stability, flowability and image quality temperature dependency.

[0005] The fluidity-modifying action of smectite is determined not only by the quality of the smectite itself, but also by the size of the smectite in the ink vehicle.
It is believed that the degree of dispersion of smectite in the ink vehicle is governed by the particle size. Therefore, when it is desired to obtain an ink having desired flow characteristics, it is essential to optimize not only the quality of the smectite but also the particle size and the stability of the degree of dispersion.

[0006]

However, there has been research and development on smectite quality.
Almost no study has been made on the particle size, and smectite generally disintegrates and swells by spontaneously absorbing water when put into water, so that means for controlling the dispersibility of smectite itself has not been established.

[0007] The flow reforming effect of smectite is that a gel structure is formed by the hydrogen bond between the ends of hydroxy groups on the side surfaces of the smectite flakes, and the smectite flakes are cross-linked with water molecules. It is thought that it is exhibited by. Therefore, even if the conventional smectite addition technology for emulsion-based stencil printing inks is applied directly to stencil printing oil-based inks such as UV inks that do not contain water, a stable fluid reforming effect can be obtained. It is considered impossible.

The present invention has been made in view of the above circumstances, and is not limited to emulsion ink for stencil printing,
An object of the present invention is to provide a stencil printing ink containing a dispersant, which can be applied to oil-based inks for stencil printing, can stably disperse smectite, and can also improve dispersibility. Is what you do.

[0009]

SUMMARY OF THE INVENTION The stencil printing ink of the present invention is characterized by containing a smectite and a polyaminoamide dispersant.

[0010] Smectite means a natural or synthetic clay mineral such as bentonite, hectorite, hydelite, saponite, etc., which is mainly composed of montmorillonite, and is a flow modifier generally widely contained in stencil printing inks. Yes, and does not imply a particular smectite.

The polyaminoamide dispersant means a dispersant containing a polyaminoamide compound. For example, the polyaminoamide compound itself may be used, or a solution in which the polyaminoamide compound is dissolved in a solvent may be used. . Here, the polyaminoamide compound is
Not only polyaminoamide itself, but also compounds such as polyaminoamide carboxylate or polyaminoamide and ester salt.For example, polyaminoamide polycarboxylate or long-chain polyaminoamide and polar acid ester salt are hydrocarbons. Those contained in the solvent are preferred.

The stencil printing ink is an ink used for stencil printing, and includes both stencil printing emulsion inks and stencil printing oil-based inks. When the stencil printing ink is an emulsion ink, the polyaminoamide dispersant is preferably a dispersant containing a polycarboxylic acid salt of polyaminoamide, and when the stencil printing ink is an oil-based ink, As the polyaminoamide dispersant, it is preferable to use a dispersant containing a salt of a long-chain polyaminoamide and a polar acid ester.

The polyaminoamide dispersant has a polyaminoamide compound content of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.1 to 3% by weight, based on the total weight of the ink. 5 to 1.5% by weight is preferred.

[0014]

The stencil printing ink of the present invention contains smectite and a polyaminoamide dispersant, so that the smectite particles are completely dispersed and a stable flow reforming effect can be obtained. The reason why such a stable flow reforming effect can be obtained is that the carboxyl group of the polyaminoamide and the smectite generate a selective electrostatic chemisorption in the wetting stage to form a gelled structure, so that the ink vehicle is formed. It is thought that the smectite particle size in the steel was optimized, the dispersibility was improved, and the dispersibility was stabilized.

As described above, the smectite particle size is optimized, the dispersibility is improved, and the dispersibility is stabilized, so that the flow reforming action of the smectite is improved, and when the ink is adjusted, the ink is passed through a roll mill. Even if the number of times (the number of roll passes) is small, the desired yield value (YieldVal
ue: It is possible to obtain the minimum amount of shear force required to cause flow, that is, the degree to which the ink retains its shape. In other words, the conventional ink containing no polyaminoamide dispersant, because the effect of flow modification of smectite was not sufficiently obtained, the yield value is low when the number of roll passes is small, and the yield value increases when the number of roll passes is increased. The stencil printing ink of the present invention has improved smectite dispersibility and its dispersibility is stable, so that the yield of the ink depends on the number of roll passes. The stencil printing ink having a desired yield value can be obtained with little change in the number of roll passes.

Further, if the dispersibility of smectite is improved, the dispersibility of the colorant contained in the ink, particularly the phthalocyanine pigment which is generally difficult to disperse, and other components contained in the ink are also improved. It is possible to improve the quality of the ink.

Further, the stencil printing ink of the present invention can obtain a sufficient dispersibility even if the number of roll passes is one, so that the dispersion time can be shortened, and the productivity of the stencil printing ink can be reduced. Improvement can be achieved.

The content of the polyaminoamide-based compound in the ink is adjusted to 0.05 to 5% by weight based on the total amount of the ink, and the carboxylic acid salt of polyaminoamide or the long-chain polyaminoamide is added to the polyaminoamide dispersant. By using a compound containing a salt of an amide and a polar acid ester, it is possible to further optimize the particle size, improve the dispersibility, and stabilize the dispersibility.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with respect to a stencil printing emulsion ink and a stencil printing oil-based ink.

The oil phase component of the emulsion ink for stencil printing includes, in addition to a dispersant and a flow modifier, a resin, a solvent, an emulsifier,
It is preferable that a coloring agent and the like be appropriately contained.

The dispersant is preferably a polyaminoamide dispersant, for example, a polyaminoamide polycarboxylate or a salt of a long chain polyaminoamide and a polar acid ester contained in a hydrocarbon solvent. A
anti-Terra-204 (containing 52% of a polycarboxylate of polyaminoamide), Disperbyk-
101 (containing 51% of a salt of a long-chain polyaminoamide and a polar acid ester, all of which are Big Chemie Japan Co., Ltd.)
Manufactured) can be preferably used.

Smectite, a flow modifier, is commonly used
Formula, (X, Y)_2-3Z₄O₁₀(OH)₂・ MH₂O ・
(Wω) (where X is Al, Fe^III, Mn^III, Cr
^III, Y is Mg, Fe ^II, Mn^II, Ni, Z
n, Li, Z are Si, Al, W is K, Na, Ca, H
₂O is interlayer water. The alkali metal represented by W is a base
And the average of the quantities is given by ω = 1/3. )
It is represented by Smectite that can be used in the present invention
Does not need to be special, even if it is natural,
That have been produced or that have been chemically modified.
You may. For example, a base material containing montmorillonite as a main component.
Magnetium, which is partially replaced with Mg
Mbentonite, calcium bentonite replaced with Ca
, Hectorite, hyderite, saponite, these
Clay Minerals and Quaternary Ammonium Salt Type Cationic Surfactant
Modified clay minerals modified with a dispersant such as dimethi
Alkylammonium hectorite, benzyldimethy
Rustearyl ammonium hectorite, distear chloride
Ril dimethyl ammonium treated aluminum silicate mug
Nesium, distearyl dimethyl ammonium chloride treatment
Montmorillonite or the like can be used.

Examples of the resin include polyamide resin, urethane resin, alkyd modified phenol resin, rosin ester resin, rosin modified alkyd resin, rosin modified phenol resin, alkyd resin, petroleum resin, oil and fat compound, modified oil and fat compound, Gilsonite, polybutadiene, water It is preferable to use added polybutadiene, acrylic resin, melamine resin, urea resin, phenol resin, polyester resin, silicone resin, epoxy resin, cellulose resin, and the like. The resin in the oil phase component has a function of further improving the dispersibility of the colorant and fixing them to printing paper. The iodine value of these resins is not particularly limited, but when the iodine value is greater than 100, the stencil printing ink rapidly dries and solidifies, causing clogging, and from the viewpoint of ink stability. Is also preferably 100 or less.

As the solvent, any non-volatile solvent or volatile solvent can be used as long as it is known to be used for stencil printing ink applications. Examples of the non-volatile solvent include motor oil, spindle oil and machine oil. Mineral oil-based solvents such as oil, liquid paraffin, and aroma-free solvent, and vegetable oils such as olive oil, soybean oil, coconut oil, tall oil, castor oil, dehydrated castor oil, and safflower oil can be used. Examples of the volatile solvent include aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, mixed solvents of aromatic hydrocarbons and aliphatic hydrocarbons, paraffinic hydrocarbon solvents, isoparaffinic hydrocarbon solvents, and naphthenic solvents. And hydrocarbon solvents. Because stencil printing is popular for general consumers such as schools and government offices due to its versatility,
Among these solvents, aliphatic hydrocarbons are more preferable from the viewpoint of safety and hygiene.

The above-mentioned solvents may be used alone or in an appropriate mixture. When mixed and used, for example, a mixing medium of spindle oil and an aliphatic hydrocarbon solvent, a spindle oil, an aliphatic hydrocarbon solvent and a castor oil and the like can be mentioned. When a non-volatile solvent and a volatile solvent are appropriately mixed and used, the mixing ratio of the non-volatile solvent / volatile solvent varies depending on the mixing ratio of the oil phase and the aqueous phase of the emulsion ink, but is 50 to 95 by weight. / 50 to 5% by weight.

Examples of the emulsifier include sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan sesquioleate and the like, higher fatty acid esters of sorbitan, fatty acid monoglyceride, fatty acid diglyceride, and the like. Nonionic surfactants such as higher alcohols, alkylphenols, and adducts of ethylene oxide such as fatty acids are preferred.

Examples of the coloring agent include known pigments having various colors,
Dyes can be used. Examples of pigments include, for example, azo-based, phthalocyanine-based, dye-based, condensed polycyclic, nitro-, and nitroso-based organic pigments (brilliant carmine 6).
B, lake red C, watching red, diazo yellow, Hansa yellow, phthalocyanine blue, phthalocyanine green, alkali blue, aniline black, etc.), cobalt, iron, chromium, copper, zinc, lead, titanium, vanadium, manganese, nickel Such as metals,
Metal oxides and sulfides, carbon blacks such as furnace carbon black, lamp black and channel black, and inorganic pigments such as loess, ultramarine blue, and navy blue are used.

The extender pigment may be contained in the oil phase and / or the aqueous phase. As the extender, a conventionally known extender can be employed, and is not particularly limited as long as it is water-insoluble fine particles. For example, clay, talc, clay, diatomaceous earth, calcium carbonate, barium sulfate, titanium oxide, alumina white, silica, kaolin, mica, inorganic fine particles such as aluminum hydroxide, polyacrylate, polyurethane, polyester,
Organic fine particles such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polysiloxane, phenol resin, epoxy resin, and benzoguanamine resin, or fine particles composed of a copolymer thereof can be used.

The water phase component of the emulsion ink for stencil printing is prepared by appropriately dissolving or mixing water, an electrolyte, a water evaporation inhibitor, a water-soluble polymer, a preservative, a fungicide, an antioxidant, a pH adjuster, and the like. Can be used. When the oil phase component does not contain a colorant, it can be contained in the aqueous phase component. As the colorant to be used, the same colorants as those used in the oil phase component can be used.

The stencil printing oil-based ink contains a resin, a solvent, a colorant, an antioxidant, and the like. These may be the same as those used for the oil phase component of the stencil printing emulsion ink. it can. In addition, U
In addition to a V-curable resin (monomer, oligomer, etc.), a polymerization initiator or the like may be added to obtain a UV-curable ink. In this case, as the UV-curable resin, polyol acrylate (for example, polypropylene glycol diacrylate, dipentaerythritol penta and hexaacrylate), polyester acrylate (for example, diacrylate of polyester diol of (anhydrous) tetrahydrophthalic acid and diethylene glycol, epoxy acrylate ( For example, it is preferable to use bisphenol A type epoxy acrylate) and phenol EO-modified acrylate.

[0031]

(Example 1) Bentonite mineral clay (SBe)
n; Chemical composition by EDX analysis manufactured by Toyohyun Yoko Co., Ltd.
SiO ₂ : 64.1, Fe ₂ O ₃ : 15.6, Al ₂ O
_{3: 14.9, SO 3: 3.4} , CaO: 1.2, Ti
O ₂ : 0.7, ZrO ₂ : 0.04, SrO: 0.03
9 (% by weight)), 15 parts by weight of an alkyd resin (manufactured by Harima Chemicals, Inc.), 6 parts by weight of carbon black MA-100 (manufactured by Mitsubishi Chemical Corporation) as a coloring agent, and No. 5 solvent (solvent) as a solvent. AF-5; manufactured by Mitsubishi Nisseki Co., Ltd.) 1
0.5 parts by weight, 2 parts by weight of hexaglycerin 5-oleate (HG-5O; manufactured by Nikko Chemicals Co., Ltd.) as an emulsifier,
Anti-T as a carboxylate of polyaminoamide
erra-204 (manufactured by Big Chemie Japan Co., Ltd.)
0.5 part by weight was sufficiently mixed and dispersed by a three-roll mill to obtain an oil phase. Next, a water phase consisting of 65 parts by weight of ion-exchanged water was added to the oil phase while mixing, and emulsification was performed to obtain a W / O type stencil printing emulsion ink.

Example 2 The same procedure as in Example 1 was carried out except that decaglycerin 6-oleate (DG-6O; manufactured by Nikko Chemicals Co., Ltd.) was used as an emulsifier and an oil phase was formed according to the formulation shown in Table 1. Thus, a W / O type stencil printing emulsion ink was obtained.

Example 3 Hexaglycerin PR15 (HG-PR-15; Nikko Chemicals Co., Ltd.) as an emulsifier
And W / O type stencil printing inks were obtained in the same manner as in Example 1 except that the oil phase was formed according to the formulation shown in Table 1).

Example 4 A W / O type stencil printing emulsion ink was obtained in the same manner as in Example 1 except that an oil phase was formed according to the formulation shown in Table 1.

Example 5 W / W was prepared in the same manner as in Example 1, except that copper phthalocyanine (manufactured by Dainippon Ink and Chemicals, Inc.) was used as a coloring agent and an oil phase was formed according to the formulation shown in Table 1. An O-type stencil printing emulsion ink was obtained.

Example 6 The procedure of Example 5 was repeated, except that decaglycerin 6-oleate (DG-6O; manufactured by Nikko Chemicals Co., Ltd.) was used as the emulsifier and the oil phase was formed by the formulation shown in Table 1. Thus, a W / O type stencil printing emulsion ink was obtained.

Example 7 Hectorite mineral clay (Be)
ntone # 38; manufactured by RHEOX, and the chemical composition by EDX analysis was SiO ₂ : 65.4, Fe ₂ O ₃ : 15.
3, Al ₂ O ₃ : 14.2, SO ₃ : 3.8, CaO:
_{0.5, TiO 2: 0.6, ZrO} 2: 0.05 ( wt%)) 8 parts by weight of carbon black as a coloring agent MA-
100 (manufactured by Mitsubishi Chemical Corporation) 5 parts by weight, Alonix M102 (manufactured by Toa Gosei Co., Ltd.) 32.4 parts by weight as a resin, Aronix M400 (manufactured by Toa Gosei Co., Ltd.) 30 parts by weight, Banbeam UV-103 ( Harima Chemicals Co., Ltd.)
20 parts by weight, Irg-369 (Ciba.
Specialty Chemicals) 3 parts by weight, Kayacure DETX (Nippon Kayaku Co., Ltd.) 0.5 part by weight, polymerization inhibitor Q-1301 (Wako Pure Chemical Industries, Ltd.) 0.1 part by weight, long chain One part by weight of Disperbyk-101 (manufactured by BYK Japan KK) as a salt of polyaminoamide and a polar acid ester was sufficiently mixed and dispersed with a three-roll mill to obtain an oil-based ink for stencil printing.

Example 8 Example 7 was repeated except that an oil-based ink was formed according to the formulation shown in Table 1 using copper phthalocyanine (manufactured by Dainippon Ink and Chemicals, Inc.) as a coloring agent.
In the same manner as in the above, an oil-based ink for stencil printing was obtained.

[0039]

[Table 1] Comparative Example 1 Carboxylic acid salt of polyaminoamide, An
A W / O type stencil printing emulsion ink was obtained in the same manner as in Example 1, except that ti-Terra-204 was not added and the formulation was changed to the formulation shown in Table 2.

Comparative Example 2 Example 2 was repeated except that the carboxylate of polyaminoamide, Anti-Terra-204, was not added and the formulation was as shown in Table 2.
In the same manner as in the above, a W / O type stencil emulsion ink was obtained.

Comparative Example 3 Example 3 was repeated except that the carboxylate of polyaminoamide, Anti-Terra-204, was not added and the formulation was as shown in Table 2.
In the same manner as in the above, a W / O type stencil emulsion ink was obtained.

Comparative Example 4 Example 5 was repeated except that the carboxylate of polyaminoamide, Anti-Terra-204, was not added and the formulation was as shown in Table 2.
In the same manner as in the above, a W / O type stencil emulsion ink was obtained.

Comparative Example 5 A salt of a long-chain polyaminoamide and a polar acid ester, Disperbyk-101, was not added, and the formulation was as shown in Table 2.
An oil ink for stencil printing was obtained in the same manner as in Example 7.

(Comparative Example 6) A salt of a long-chain polyaminoamide and a polar acid ester, Disperbyk-101, was not added, and the formulation was as shown in Table 2.
An oil ink for stencil printing was obtained in the same manner as in Example 8.

[0045]

[Table 2] (Evaluation Method of Oil Phase Component of Stencil Printing Ink) Examples 1 to 6
The oil phase component of the emulsion ink for stencil printing of Comparative Examples 1 to 4 and the oil-based ink for stencil printing of Examples 7 and 8 and Comparative Examples 5 and 6 were applied three times to a three-roll mill (manufactured by Inoue Seisakusho, small type). Then, the dispersion was dispersed (roll pass), and the viscosity of each dispersion was measured by a flow curve at 23 ° C. using a cone plate type viscometer (manufactured by HAAKE, stress control type) to obtain a yield value. The particle size of each dispersion was measured with a grind gauge (manufactured by Yasuda Seiki Co., Ltd., maximum 25 μm). Furthermore, the roll seizure phenomenon (the phenomenon of smectite and colorant seizing on the roll surface) at the time of passing once through a three-roll mill was also evaluated. X.
The results are shown in Table 3 and FIGS. 1, 2, and 3.

[0046]

[Table 3] FIG. 1 is a graph plotting the relationship between the average yield value of the oil phase component of the emulsion ink for stencil printing and the number of roll passes (solid lines are average yield values in Examples 1 to 6, and broken lines are Comparative Examples 1 to 6).
FIG. 2 is a graph plotting the relationship between the average yield value of the stencil printing oil-based ink and the number of roll passes (solid lines are average yield values in Examples 7 and 8, and dashed lines are Comparative Example 5).
6 average yield value). FIG. 3 is a graph in which the relationship between the particle size and the number of roll passes when copper phthalocyanine is used as the pigment is plotted (the solid line is the average particle size of Examples 5 and 6, the broken line is the average particle size of Example 8, and the dashed line is Comparative Example 4). , 6).

As is clear from Table 3 and FIGS. 1 and 2,
The oil phase component of the emulsion ink for stencil printing and the oil-based ink for stencil printing of the present invention have a low dependence of the yield value on the number of roll passes, so the yield value is high even with one roll pass, and the dispersibility is extremely good. It can be seen that the dispersibility is stable. Further, as is clear from Table 3 and FIG. 3, even with an ink using copper phthalocyanine, which is said to have poor dispersibility, as a coloring agent, the particle size can be considerably reduced by one roll pass. It can be seen that the dispersibility has been improved.

(Evaluation Method of Stencil Printing Inks)
Stencil printing machine lithograph FR395 (Riso Kagaku Kogyo Co., Ltd.) using the stencil printing emulsion ink and the stencil printing oil-based ink obtained in Comparative Examples 1 to 6 (all three roll mill dispersions were performed once). Stencil printing). In Examples 7 and 8 and Comparative Examples 5 and 6, U
For the V-curable ink, a UV irradiator was set on the paper discharge table of the stencil printing machine, and stencil printing was performed while irradiating UV. Printing paper was ideal paper thinner (product designated by Riso Kagaku Kogyo Co., Ltd.).

The stencil printing is performed with this stencil printing ink for 10 times.
000 sheets were printed, the printed matter was observed, and the result was evaluated as ○ when there was no clogging of the plate and there was no image loss, and evaluated as x when there was clogging of the plate and there was image loss. After printing, the print density of the solid portion of the printed matter was measured by an OD meter (RD920, manufactured by Macbeth Co., Ltd.). further,
After performing stencil printing with a stencil printing machine, it was left at room temperature for one day. Thereafter, the sample was rubbed with a clock meter and visually observed, and the case where there was almost no rubbing was evaluated as O, and the case where rubbing was noticeable was evaluated as X. Table 4 shows the results.

[0050]

[Table 4] As is clear from Table 4, the stencil printing ink of the present invention had good dispersibility, so that clogging of the plate did not occur, the printing density was optimal, and the rubbing was strong.

As described above, the stencil printing ink of the present invention has significantly improved smectite dispersibility as compared with the conventional stencil printing ink containing no polyaminoamide dispersant, and also has a good dispersibility. It ’s extremely stable,
It is easy to set the ink to the desired yield value, and the dispersibility of various components including the colorant contained in the ink is good, so the image quality printed with this stencil printing ink is also lower than before. It was excellent.

[Brief description of the drawings]

FIG. 1 is a graph plotting the relationship between the average yield value of the oil phase component of a stencil printing emulsion ink and the number of roll passes.

FIG. 2 is a graph plotting the relationship between the average yield value of a stencil printing oil-based ink and the number of roll passes.

FIG. 3 is a graph plotting the relationship between the particle size and the number of roll passes when copper phthalocyanine is used as a pigment.

Claims (4)

[Claims] 1. A stencil printing ink comprising a smectite and a polyaminoamide dispersant. 2. The method according to claim 1, wherein the polyaminoamide-based compound of the polyaminoamide dispersant is added to the ink in an amount of 0.
2. The stencil printing ink according to claim 1, wherein the amount is from 0.5 to 5% by weight. 3. The stencil printing ink according to claim 1, wherein the polyaminoamide dispersant contains a carboxylic acid salt of polyaminoamide. 4. The stencil printing ink according to claim 1, wherein the polyaminoamide dispersant contains a salt of a long-chain polyaminoamide and a polar acid ester.