JP4423072B2 - Electrostatic printing sheet using liquid toner receptive layer forming ink - Google Patents

Description

The present invention relates to an electrostatic printing sheet using a liquid toner receiving layer i ink.

  Recently, an image forming method for a plastic film, paper or the like using an electrophotographic method has attracted attention. Since this method does not require a plate making process as is well known, it is the most suitable method for producing a small amount of various kinds of printed matter. In particular, the electrophotographic development method using liquid toner has a high-definition and high-quality output image compared to the case of using powder toner, and in terms of image quality, it is comparable to the gravure printing method and offset printing method. Has reached.

  However, when liquid toner is used, paper that can be used is limited to coated paper from the viewpoint of printability such as adhesion to liquid toner. There was a problem that it was not possible to write well, etc., and it was not possible to erase well with an eraser after writing.

In order to improve this problem, there has been proposed an ink for forming a liquid toner receiving layer using an emulsion containing an ethylene / acrylic acid resin having an aqueous continuous phase (see Patent Documents 1 to 4).
JP2003-195548 JP 2003-195549 A JP 2003-195550 A JP 2003-215831 A

Liquid toner receptive layer forming inks using emulsions containing ethylene-acrylic acid-based resins having an aqueous continuous phase are advantageous in that they are inexpensive, have good coatability, and can be applied immediately after papermaking. When partially coated on paper that has been partially printed and dried, it is necessary to coat the entire surface in order for the paper to stretch or corrugate. Therefore, the manufacturing process is not completed in one process, and the process becomes complicated, increasing costs. In addition, there is a problem that when the entire surface is coated, a liquid toner receiving layer is formed in a portion where the liquid toner is not printed, and the material is wasted, which causes a burden on the environment.
The purpose of the present invention is to solve the conventional problems, is partially printed can easily be partially coated on the dried paper, and paper used is excellent in fixing properties of the liquid toner is limited to the coated paper Ordinary paper, synthetic paper, plastic film, etc. can be used, and it has excellent writing performance with pencils, water-based pens, ballpoint pens, etc., can be erased well with an eraser after writing, and is commercially available after writing with an aqueous pen. electrostatic printing to form a liquid toner receiving layer on a sheet substrate using an in-click capable of forming a liquid toner receiving layer having characteristics such may be erased cleanly with ink mending agent on the sheet (the sheet substrate) Is to provide a sheet.

That is, claim 1 of the present invention provides water in an emulsion containing an ethylene / acrylic acid-based resin having a water-based continuous phase and a hydrophilic UV-curable acrylic component at a predetermined location on the surface of a sheet substrate made of paper. It is separated out of the system by providing a liquid toner receiving layer by using a liquid including toner-receiving layer forming ink ethylene-acrylic acid resin which is converted into oil-based continuous phase consisting of the acrylic component as essential components an electrostatic printing sheet, wherein the Nalco.

According to a second aspect of the present invention, in the electrostatic printing sheet according to the first aspect, fine particles are further blended in the liquid toner-receiving layer forming ink .

According to a third aspect of the present invention, in the electrostatic printing sheet according to the second aspect, the blending ratio of the ethylene / acrylic acid resin to the fine particles is ethylene / acrylic acid resin: the fine particles = 1. It is 9 to 9: 1 (mass ratio).

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The sheet for electrostatic printing according to claim 1 of the present invention includes an ethylene / acrylic acid resin having a water-based continuous phase and a hydrophilic UV-curable acrylic component at a predetermined position on a sheet base material surface made of paper. the water in the emulsion was separated from the system, see it contains the ethylene-acrylic acid resin which is converted into oil-based continuous phase consisting of the acrylic component as essential components, partial printed easily portion coating the dried sheet When a liquid toner receiving layer (for example, a thin film coating) is formed using an ink for forming a liquid toner receiving layer having high print productivity, the liquid toner receiving layer can improve the adhesion and fixability of the liquid toner. For example, after the cellophane tape has been applied to the print section where the liquid toner has been printed on the liquid toner receiving layer, the print section will peel off even if the cellophane tape is peeled off. In Ino, the sheet substrate to be used is not limited to expensive coated paper, on which can use ordinary paper, the liquid toner receiving layer pencils, aqueous pen, is excellent like the writability by ballpoint, also writing It can be erased satisfactorily with an eraser later , and can be erased neatly with a commercially available ink eraser after writing with an aqueous pen , and has the remarkable effect of being inexpensive .

According to a second aspect of the present invention, in the electrostatic printing sheet according to the first aspect , the liquid toner receiving layer forming ink is further mixed with fine particles, and the formed liquid toner The receiving layer has a further remarkable effect of being excellent in the adhesion and fixing properties of the liquid toner.

According to a third aspect of the present invention, in the electrostatic printing sheet according to the second aspect, the blending ratio of the ethylene / acrylic acid resin and the fine particles is ethylene / acrylic acid resin: the fine particles = 1: 9 to 9: 1 (mass ratio) is characterized in that the printing productivity is higher, and the formed liquid toner receiving layer is more excellent in the adhesion and fixing properties of the liquid toner. Play.

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Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a cross-sectional explanatory view showing an embodiment of the sheet of the present invention.
In FIG. 1, a sheet 1 of the present invention uses an ink used in the present invention , and a liquid toner receptive layer 3 is formed on the entire surface of a sheet substrate 2 and at a predetermined position on the back surface thereof. A print 4 is printed on the liquid toner receiving layer 3 by a printer (not shown).

  The ethylene / acrylic acid resin used in the present invention is a resin obtained by copolymerizing ethylene and acrylic acid, and the acrylic acid ratio is not particularly limited, but the acrylic acid ratio is 2 to 30 mol%, and the weight average molecular weight. Of approximately 8000 to 20000 is preferably used. The ethylene / acrylic acid resin is used in a form dispersed in water or dissolved in an organic solvent. However, ethylene / acrylic acid resins are usually used in a form in which acrylic acid is dispersed in water in the form of an alkali salt such as ammonia or amine or a metal salt such as sodium or zinc.

The hydrophilic acrylic component used in the present invention is an acrylic component that dissolves well in normal temperature water and does not separate or precipitate even if left standing, and has a known hydrophilic monomer and It can be arbitrarily selected from acrylic oligomers having hydrophilic properties.
Specific examples of the acrylic monomer having hydrophilicity include, for example, polyethylene glycol having an ethylene glycol unit in the molecule (n is 3 or more, approximately 14 or less), diacrylate, trimethylolpropane EO modification (n is 3 Above, approximately 14 or less) Triacrylate, phenol EO-modified (n is 3 or more, approximately 14 or less) modified acrylate, 2-hydroxyethyl acrylate (HEA) having 2-hydroxyethyl in the molecule, 2-hydroxypropyl acrylate 4-hydroxybutyl acrylate, pentaerythritol triacrylate, monohydroxyethyl acrylate phthalate, and the like.
These hydrophilic monomers may be used alone or in combination of two or more.

  In the case of an acrylic component having an ethylene glycol unit in the molecule, n of the polyethylene glycol unit is 3 or more, and if n is less than 3, the hydrophilicity is inferior. The upper limit of n is not particularly limited, but is about 14 or less in the case of commercially available products.

In the present invention, it is preferable to appropriately mix and use a polyimine-based resin with an ethylene / acrylic acid-based resin because the adhesion and fixability of the liquid toner can be improved. The polyimine-based resin is not particularly limited as long as it is a polymer containing one or more of primary, secondary, and tertiary amino groups in the molecular skeleton.
Specific examples of the polyimine-based resin include polyalkyleneimines such as polyethyleneimine and polypropyleneimine; polyalkyleneimines and aldehyde compounds, ketone compounds, alkyl halide compounds, isocyanate compounds, thioisocyanate compounds, active olefin compounds, and epoxies. Compound, cyanamide compound, guanidine compound, urea, thiourea, carboxy compound, acid anhydride, acyl halide compound, etc .; reaction product of carboxy-containing acrylic resin and alkylene imine, amino group-containing acrylic resin, polyalkylene Block polymer of imine and polyalkylene oxide, polycondensate of alkylene dichloride and alkylene polyamine; polyalkylene polyamine, polyamide polyamine, polyamide polyamine -Epichlorohydrin resin, polyvinyl polyamine, polyallyl polyamine, Mannich reaction product of polyacrylamide and formalin, amine compound; copolymer of vinyl lactam compound and acrylamide; polyvinyl pyridine, polyvinyl imidazoline, polyalkylaminoethyl acrylate, chitosan, aniline And a polycondensate of formalin and a polycondensate of alkylenediamine and epichlorohydrin.
Among these, polyethyleneimine and its derivatives can be preferably used in the present invention. The molecular weight of the polyimine resin used in the present invention is preferably 100 or more, particularly preferably from 3 to 1,000,000.

  When blending and using a polyimine resin in the present invention, the blending ratio of the ethylene / acrylic resin and the polyimine resin is not particularly limited, but the ethylene / acrylic resin: polyimine resin = 1. It is preferably 5 to 5: 1 (mass ratio), more preferably 1: 4 to 4: 1, and particularly preferably 1: 2 to 2: 1. When the blending ratio of the ethylene / acrylic acid resin is less than 1, other characteristics are good, but the printed ink is difficult to disappear and the ink erasing ability may be deteriorated. When the blending ratio of the ethylene / acrylic acid resin exceeds 5, the writing property and the eraser suitability deteriorate. If the blending ratio of the polyimine resin is less than 1, the writing property and the eraser suitability may be deteriorated. If the blending ratio of the polyimine resin is more than 5, other characteristics are good, but the printed ink is hard to disappear and the ink erasability is good. May get worse.

In order to obtain an ink for forming a liquid toner receiving layer used in the present invention , an ethylene / acrylic acid resin having an aqueous continuous phase and an aqueous emulsion containing a hydrophilic acrylic component or further a polyimine resin are used in combination as starting materials. In addition, using other resins having an aqueous continuous phase in combination, the water in the aqueous emulsion is solidified, foamed, solid-liquid separated, bumped using known means such as vacuum distillation, flushing, hot air drying, etc. Vaporize the water without causing it to separate out of the system.
By separating the water out of the system, it is converted into an oil-based continuous phase composed of a hydrophilic acrylic component without agglomerating ethylene / acrylic acid resin, etc., and ethylene / acrylic is contained in the oil-based continuous phase. An ink for forming a liquid toner receiving layer used in the present invention can be obtained which contains an acid resin as an essential component or further contains fine particles such as a polyimine resin in an emulsion state.

The fine particles used in the present invention are not particularly limited, and hydrophilic fine particles, hydrophobic fine particles, and mixtures thereof can be used.
As a specific example of the fine particles used in the present invention, for example, for silica fine particles, Nippon Steel SS-10F, SS-15, SS-10A, SS-20, SS-30P, SS-30S, SS- 40, SS-50, SS-50A, SS-60, SS-70, SS-100, SS-10F, SS-50F, SS-50B, SS-50C, SS-72F, SS-170X, SS-178B, etc. , Tokuyama Fine Seals A, B, USF, E50, E70, T32, X12, X30, X37, X37B, X40, X45, X60, X70, X80, RX70, K41, F80, F80B, P8, CMF, etc. (Cabot Corp., Caboth Purse II), titanium dioxide fine particles (Nippon Aerosil Co., Ltd. T805), Examples include lumina fine particles, natural zeolite fine particles, synthetic zeolite fine particles, calcium carbonate fine particles (Brillant-15, manufactured by Shiroishi Calcium Co., Ltd.), activated clay fine particles, glass fine particles, and shirasu balloon fine particles. These may be used alone or in combination of two or more.
Among these, one or more fine particles selected from silica fine particles and calcium carbonate fine particles can be preferably used.

  The blending ratio of the ethylene / acrylic acid resin and fine particles used in the present invention is not particularly limited, but is ethylene / acrylic acid resin: fine particles = 1: 9 to 9: 1 (mass ratio). It is preferably 1: 4 to 4: 1, particularly preferably 1: 2 to 2: 1. When the blending ratio of the ethylene / acrylic acid resin is less than 1, the fixability of the liquid toner is deteriorated, and when the cellophane tape is stuck or peeled off, the printed part may be peeled off. When the blending ratio of the ethylene / acrylic acid resin exceeds 9, the writing property and the eraser suitability deteriorate. If the blending ratio of the fine particles is less than 1, the writing property may be deteriorated. If the blending ratio of the fine particles exceeds 9, the suitability of the printing ink may be lowered, and the surface strength of the liquid toner receiving layer is lowered. However, since the fixability of the liquid toner may be deteriorated, neither is preferable.

In order to cure the ink used in the present invention with ultraviolet rays, a photopolymerization initiator can be added to the ink used in the present invention. As the photopolymerization initiator, any conventionally used photopolymerization initiator can be preferably used. Typical examples are an intramolecular bond open type and an intermolecular hydrogen abstraction type. The intramolecular bond open type is a type that generates radicals by molecular cleavage, and examples thereof include benzoyl alkyl ether, benzyl dimethyl ketal, diethoxyacetophenone, acyloxime ester, chlorinated acetophenone, and hydroxyacetophenone. The intermolecular hydrogen abstraction type is a type that generates radicals by intermolecular hydrogen abstraction, and examples thereof include benzophenone, Michler's ketone, dibenzosuberone, 2-ethylanthraquinone, and isobutylthioxanthone. Examples of the photopolymerization initiator used together with the photopolymerization initiator include a photopolymerization initiation assistant or sensitizer, and amines, sulfones, and phosphines can be used.
A known additive can be added to the ink used in the present invention , if necessary. Examples of additives include viscosity modifiers, anti-aging agents, pH adjusters, antifoaming agents, various stabilizers, colorants, roll transferability improvers such as glycerin, and the like.

  The thickness of the liquid toner receiving layer may be thin and is not particularly limited, but is preferably about 0.01 to 5.0 μm, and more preferably about 0.05 to 1.0 μm. Although it depends on the blending ratio of the ethylene / acrylic acid resin and fine particles, if the thickness of the liquid toner receiving layer is less than 0.01 μm, it is difficult to obtain a stable fixability of the liquid toner, which exceeds 5.0 μm. There is a risk of blocking after winding.

The ink coating method used in the present invention is not particularly limited, and examples thereof include a manual coating method such as brush coating, and an automatic coating method.
The ink used in the present invention is, for example, a predetermined material on at least one surface of a sheet substrate by a coating means such as a gravure coater, flexo, air knife coater, bar coater, blade coater, reverse roll coater, kiss roll coater, cast coater, curtain coater. The electrostatic printing sheet of the present invention can be produced by coating on the part and drying and curing as necessary. The ink used in the present invention may be diluted with a solvent or the like optimal for the concentration suitable for each coater.

As the sheet base material used in the present invention, synthetic paper or synthetic films such as polyethylene, transparent polyethylene terephthalate, polypropylene, and vinyl chloride can be used in addition to ordinary paper. When these synthetic films are used, the surface of the substrate is preferably subjected to a surface treatment such as a mat treatment or a corona treatment. The coating amount of the ink used in the present invention on the surface of the sheet substrate is not particularly limited as long as the coating amount is such that the thickness of the liquid toner receiving layer is about 0.01 to 5.0 μm. For example 0.5 to 30 g / m ^2, preferably not 3 to 20 g / m ^2, more preferably at 5 to 15 g / m ^2.
Ordinary paper is composed mainly of wood pulp and pigment. Wood pulp includes chemical pulps such as LBKP and NBKP, mechanical pulps such as GP, PGW, RMP, TMP, CTMP, CMP, and CGP, and pulps such as waste paper pulp such as DIP. Binder, sizing agent, fixing agent, yield improver, cationizing agent, paper strength enhancer, etc. are mixed using one or more kinds of additives such as long net paper machine, circular net paper machine, twin wire paper machine etc. It can be manufactured with various devices, and can be made with acid, neutral, or alkaline.

  The electrostatic toner for developing an electrostatic charge is not particularly limited, and a known toner particle dispersed in water and / or an organic solvent can be used. Generally, toner particles are composed of a fixing resin for fixing and fixing the toner particles, a colorant for visualization, a charge adjusting agent for adjusting electrical characteristics of the liquid toner, and the like.

  As the fixing resin, known resins that have been conventionally used for electrostatic toners can be used, and thermoplastic resins are particularly preferable. For example, polystyrene, styrene-acrylic acid copolymer, polyacrylic acid are preferable. Polyethylene, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, polypropylene, polyester, polyurethane, polyamide and the like can be used alone or in combination.

  As the colorant, known pigments and / or dyes that have been conventionally used in liquid toners for electrostatic charge development can be used. Examples of the colorant include Hansaero, Benzidine Aero, Benzidine Orange, Fast Red, Brilliant Carmine 3B, Copper Phthalocyanine Blue, Phthalocyanine Green, Spirit Black, Oil Blue, Alkaline Blue, Rhodamine 6B, Nigrosine, Examples thereof include carbon black, dichloroquinacridone, isoindoline, and titanium oxide.

  Examples of charge control agents include metal salts of fatty acids such as naphthenic acid, octenoic acid, oleic acid, stearic acid, metal salts of sulfosuccinic acid esters, nonionic surfactants such as polyoxyethylated alkylamines, lecithin, and linseed. Examples of known charge control agents include oils and fats such as oil, polyvinyl pyrrolidone, and organic acid esters of polyhydric alcohols.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

50 mass% ethylene / acrylic acid resin (trade name: AD-37F1 (manufactured by Toyo Morton)) water-based emulsion 80 mass parts (solid content 40 mass parts) in a 300 ml sealed container (with a stirrer) connected to a vacuum pump ) And 50 parts by mass of polyethylene glycol diacrylate (trade name: Aronix M-240 (manufactured by Toagosei Co., Ltd.)). The obtained liquid mixture is heated to 45 ° C., further evacuated to reduce the atmospheric pressure in the sealed container to about 10 Pa, and moisture is removed while maintaining this state for about 3 to 4 hours. Is reduced to 1% by mass or less.
7 parts by mass of calcium carbonate fine particles (trade name: Brilliant-15, manufactured by Shiraishi Calcium Co., Ltd.) are kneaded with the obtained liquid. Furthermore, 5 parts by mass of a photopolymerization initiator (trade name: BYCURE 55 (manufactured by Akzo Nobel)) and 3 parts by mass of acrylic acid dimer (trade name: Aronix M-5600 (manufactured by Toagosei Co., Ltd.)) were added as an additive. Thereafter, the liquid toner receiving layer forming ink used in the present invention was obtained by kneading using a three-roll mill.
The prepared ink used in the present invention is offset-printed on a high-quality paper (70 kg continuous amount) to 2.5 g / m ² using a resin relief plate to form a liquid toner receiving layer, and then an ultraviolet lamp ( The liquid toner receiving layer was cured by irradiating with ultraviolet rays using a high pressure mercury lamp, ozoneless, 160 w / cm, 2 lamps).
(1) Liquid toner fixability, (2) Writability, (3) Eraser suitability, (4) Ink erase suitability, (5) Partial coating suitability were evaluated by the following test methods, and the evaluation results are shown in Table 1. .

Test method:
(1) Liquid toner fixing property: Printing was performed on the liquid toner receiving layer with a digital printer (UltraStream (Hewlett Packard)). A commercially available cellophane tape is affixed to the printed part to a length of about 10 cm, and is sufficiently affixed by reciprocating a 2 kg weight roller (width 50 mm). The sample with the tape attached is left in an atmosphere at a temperature of 23 ° C. and a humidity of 50% for 1 hour, and then slowly peeled off. Then, the liquid toner print part after peeling is observed and evaluated.
Evaluation criteria:
○: No print portion is taken.
Δ: There are traces taken in fine dots.
X: The print part is largely peeled off.

(2) Writability: Written using a drawing tester (pencil hardness: HB, drawing load: 200 g) on the liquid toner receiving layer. And writeability is evaluated.
Evaluation criteria:
○: Can be written without resistance.
Δ: Some resistance.
X: There is resistance and writing cannot be done neatly.

(3) Eraser suitability: Writing is performed on the liquid toner receiving layer using a drawing tester (pencil hardness: HB, drawing load: 200 g). Then, the evaluation is made by erasing the writing part with a plastic eraser.
Evaluation criteria:
○: Can be erased neatly.
Δ: Slightly unerasable and a slight mark remains.
×: Can hardly be erased.

(4) Ink erasability: A water-based red pen (red ink fountain pen) is used for writing on the liquid toner receiving layer. After the writing part is sufficiently dried, the ink erasability is evaluated using a commercially available ink eraser (manufactured by Maru Kasei Co., Ltd.).
Evaluation criteria:
○: Can be erased neatly.
Δ: Slightly unerasable and a slight mark remains.
×: Can hardly be erased.

(5) Suitability for partial coating: Liquid toner-forming ink was applied to high-quality paper (70 kg continuous amount) in a size of 5 cm × 5 cm, and the paper surface after drying was observed. And the surface state is evaluated.
Evaluation criteria:
○: There is no phenomenon such as undulation, and it is not different from other parts other than the coated surface.
Δ: Slight undulation is seen on the paper, but in a practically usable range.
X: The paper surface is wavy and cannot be used as paper.

The present invention was carried out in the same manner as in Example 1 except that the ethylene / acrylic acid resin used in Example 1 was changed to 60 parts by mass (solid content: 30 parts by mass) and the polyethylene glycol diacrylate was changed to 60 parts by mass. The liquid toner-receiving layer forming ink used in 1 was prepared, and a high-quality paper (sheet of the present invention) provided with the liquid toner-receiving layer was obtained.
In the same manner as in Example 1, (1) liquid toner fixing property, (2) writing property, (3) eraser suitability, (4) ink eraser suitability, and (5) partial coating suitability were evaluated. Shown in

The present invention was carried out in the same manner as in Example 1 except that the ethylene / acrylic acid resin used in Example 1 was changed to 40 parts by mass (solid content: 20 parts by mass) and the polyethylene glycol diacrylate was changed to 80 parts by mass. The liquid toner-receiving layer forming ink used in 1 was prepared, and a high-quality paper (sheet of the present invention) provided with the liquid toner-receiving layer was obtained.
In the same manner as in Example 1, (1) liquid toner fixing property, (2) writing property, (3) eraser suitability, (4) ink eraser suitability, and (5) partial coating suitability were evaluated. Shown in

Example 1 Ethylene-acrylic acid was used in the resin other ethylene-acrylic acid resin: it was changed to (trade name Zeikusen A (manufactured by Sumitomo Seika Chemicals Co., Ltd.)) in the same manner as in Example 1 in the present invention A liquid toner receiving layer forming ink to be used was prepared, and a high-quality paper (sheet of the present invention) provided with the liquid toner receiving layer was obtained.
In the same manner as in Example 1, (1) liquid toner fixing property, (2) writing property, (3) eraser suitability, (4) ink eraser suitability, and (5) partial coating suitability were evaluated. Shown in

Liquid toner-receiving layer forming ink used in the present invention in the same manner as in Example 1 except that the calcium carbonate fine particles used in Example 1 were changed to silica fine particles (trade name: Aerosil 200CF (manufactured by Nippon Aerosil Co., Ltd.)). And a high-quality paper (sheet of the present invention) provided with a liquid toner receiving layer was obtained.
In the same manner as in Example 1, (1) liquid toner fixing property, (2) writing property, (3) eraser suitability, (4) ink eraser suitability, and (5) partial coating suitability were evaluated. Shown in

(Comparative Example 1)
(1) Liquid toner fixability, (2) Writability, and (3) Eraser suitability, except that no special coating was applied to the fine paper (no liquid toner receiving layer was provided). (4) Ink erasing suitability and (5) Partial coating suitability were evaluated, and the evaluation results are shown in Table 1.

(Comparative Example 2)
A comparative ink was prepared in the same manner as in Example 1 except that the ethylene / acrylic acid resin used in Example 1 was not used, and a fine paper (comparative sheet) provided with a liquid toner receiving layer was prepared. Obtained. In the same manner as in Example 1, (1) liquid toner fixing property, (2) writing property, (3) eraser suitability, (4) ink eraser suitability, and (5) partial coating suitability were evaluated. Shown in

(Comparative Example 3)
An ink for comparison was prepared in the same manner as in Example 1 except that the evacuation performed in Example 1 was not performed, and an offset printing was attempted on fine paper in the same manner as in Example 1. could not.

(Comparative Example 4)
Dispersion 500 in which ethylene / acrylic acid resin used in Example 1 was dispersed in 150 parts by mass (solid content: 75 parts by mass) and calcium carbonate fine particles used in Example 1 were dispersed in 15 parts by mass in distilled water in advance. Mass parts (solid content: 75 parts by mass) were mixed, and an appropriate amount of a thickener was added to obtain a liquid toner receiving layer forming ink for comparison of 150 mPa · s. Using the flexo coating machine, the obtained ink was partially coated (5 cm × 5 cm) on fine paper (70 kg continuous weight) to 4 g / m ² , followed by hot air drying, A fine paper (comparative sheet) provided with a toner receiving layer was obtained. In the same manner as in Example 1, (1) liquid toner fixing property, (2) writing property, (3) eraser suitability, (4) ink eraser suitability, and (5) partial coating suitability were evaluated. Shown in

From Table 1, the onset Ming sheet over preparative examples 1-5 (1) Liquid toner fixability, (2) writing property, (3) Eraser suitability, (4) the ink off suitability, (5) partial coating It can be seen that both are suitable for construction.
On the other hand, the sheets for comparison of Comparative Examples 1 and 2 were (1) poor in liquid toner fixing property, and the ink having the aqueous continuous phase of Comparative Example 3 could not be offset printed, so other evaluation could not be performed. The ink having the aqueous continuous phase of Comparative Example 4 could be flexographically printed, but (5) the partial coating suitability was inferior and could not be used as paper.

The electrostatic printing sheet of the present invention comprises water in an emulsion containing an ethylene / acrylic acid-based resin having a water-based continuous phase and a hydrophilic UV-curable acrylic component at a predetermined location on a sheet base material made of paper. is separated from the system, it viewed including the acrylic ethylene-acrylic acid resin which is converted into oil-based continuous phase consisting of components as essential components, be readily portion coating the portion printed dried paper When a liquid toner receptive layer (for example, thin film coating) is formed using a liquid toner receptive layer forming ink that can be printed and has high productivity, the liquid toner receptive layer has excellent adhesion and fixability of the liquid toner. For example, after attaching the cellophane tape to the print portion where the liquid toner is printed on the liquid toner receiving layer, the print portion does not peel off even if the cellophane tape is peeled off. Sheet substrate for use is not limited to expensive coated paper, on which can use ordinary paper, the liquid toner receiving layer pencils, aqueous pen, it is excellent like the writability by ballpoint pen, also with an eraser after writing It can be erased well, can be erased neatly with a commercially available ink eraser after writing with a water-based pen , and has a remarkable effect that it is inexpensive .

It is a section explanatory view showing one embodiment of the sheet of the present invention.

DESCRIPTION OF SYMBOLS 1 Sheet | seat 2 of this invention Sheet | seat base material 3 Liquid toner receiving layer 4 Printing

Claims (3)

Water in an emulsion containing an ethylene / acrylic acid resin having a water-based continuous phase and a hydrophilic UV-curable acrylic component is separated from the system at a predetermined location on the surface of the sheet substrate made of paper , and the acrylic electrostatic printing, characterized in. Doing so provided a liquid toner receiving layer by using a liquid including toner-receiving layer forming ink ethylene-acrylic acid resin which is converted into oil-based continuous phase consisting of the system components as essential components Sheet. 2. The electrostatic printing sheet according to claim 1, wherein fine particles are further blended in the liquid toner-receiving layer forming ink . 3. The static according to claim 2, wherein a blending ratio of the ethylene / acrylic acid resin and the fine particles is ethylene / acrylic acid resin: the fine particles = 1: 9 to 9: 1 (mass ratio). Sheet for electroprinting.

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