JPH1076744A - Printed matter by electrostatic charge liquid development method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise adhesion of electrostatic charge developing liquid toner to a matter to be printed by a method wherein a plastic film or the like of the matter to be printed is coated in advance with a primer consisting of ethylene acrylate resin or polybutadiene resin. SOLUTION: A primer layer consisting of ethylene acrylate resin or polybutadiene resin, and an image layer by a static charge liquid developing method are successively formed on a matter to be printed to make a printed matter. A film thickness of the primary layer is preferably 0.01-5.0μm, and more preferably 0.05-1.0μm. As a concrete example, there are a plastic film of polyester film or the like, mirror coat paper, synthetic paper, etc. As electrostatic charge developing liquid toner forming the image layer, well-known toner particles dispersed in water and/or organic solvent can be used. Further, to the primary, curing agents of isocyanate, imine, etc., can be added.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed matter formed by an electrostatic liquid developing method having good adhesion to a printing medium.

[0002]

2. Description of the Related Art As a method of printing a high-definition image on a plastic film, a plastic sheet, or the like, there are a gravure printing method, an offset printing method, a flexographic printing method,
A silk screen printing method and the like have been conventionally used and occupy a firm position in terms of printing speed, printing quality and the like.
However, any of the printing methods requires a lot of time and cost in the plate making operation. As a result, when printing in large quantities, the cost per printed material is kept low, which is a great merit, but it is difficult to cope with printing only a small amount.

[0003] On the other hand, in recent years, the demands of consumers have been diversified, and since the same thing is printed in large quantities, the tendency to print a small number of specific things has become remarkable. Therefore, a method of forming an image on a plastic film, paper, or the like using electrophotography has recently attracted attention. This method does not require a plate-making process, as is well known, and is the most suitable method for producing small-quantity, multi-product prints. In particular, an electrophotographic developing method using a liquid toner is a powder toner.
The output image has higher definition and better quality as compared with the case where the image is used, and the image quality has reached a level comparable to the gravure printing method and the offset printing method.

[0004] However, when a liquid toner is used, the adhesion between the toner and the film is weak when the printing medium is a plastic film, and when the printing medium is paper, the adhesion depends on the type of coating agent on the paper surface. There is a problem that the coating agent is weak and the choice of the coating agent is narrow. In order to improve the adhesion between the plastic film or paper and the liquid toner, studies have been made on a fixing resin, a fixing system, and the like. However, the temporal stability of the liquid toner or the liquid toner for electrophotography has been studied. Are often inferior in basic physical properties, and a practical level liquid toner has not been realized.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to improve the adhesion between a liquid toner for electrostatic charge development and a plastic film or paper to be printed.

[0006]

Means for Solving the Problems The present inventors have previously coated a primer made of an ethylene / acrylic acid resin or a polybutadiene resin on a plastic film or paper to be used as a printing medium. As a result, it was found that the adhesion between the electrostatic toner and the printing medium was significantly improved, and the present invention was achieved.

That is, the present invention relates to a printed material in which a primer layer made of an ethylene / acrylic acid resin or a polybutadiene resin and an image layer formed by an electrostatic charge liquid developing method are sequentially formed on a printing medium. The present invention also relates to the printed matter, wherein the primer layer has a thickness of 0.01 to 5.0 μm.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The primer layer of the present invention is formed on a substrate by applying a primer obtained by dissolving or dispersing an ethylene / acrylic acid resin or a polybutadiene resin in water and / or an organic solvent. Formed. A curing agent such as an isocyanate-based or imine-based primer can be added to the primer. The ethylene-acrylic acid resin is a resin obtained by copolymerizing ethylene and acrylic acid, and a resin having an acrylic acid ratio of 2 to 30 mol% and a weight average molecular weight of 8,000 to 20,000 is preferably used. The ethylene / acrylic acid-based resin is usually used in a form in which acrylic acid is converted into an alkali salt such as ammonia or amine or a metal salt such as sodium or zinc and dispersed in water. As the polybutadiene-based resin, those having a weight-average molecular weight of 5,000 to 10,000 are preferably used. Usually, the polybutadiene-based resin is dissolved in an aromatic organic solvent or added with a carboxylic acid to form an alkali salt such as ammonia or amine. Used in a dispersed form.

The thickness of the primer layer is 0.01 to 5.0.
μm, and more preferably 0.05 to 1.0 μm. When the thickness of the primer layer is less than 0.01 μm, stable adhesion is hardly obtained, and when the thickness exceeds 5.0 μm, blocking occurs easily after winding the printed material. The application of the primer may be performed, for example, by using an air doctor coater, a blade coater, a reverse roll coater, or a gravure coater.
This is performed by using a coater, a kistrol coater, a cast coater, a curtain coater, or the like. Among them, a blade coater and a gravure coater are preferably used.
When the primer is applied with a coater, the primer is
It may be diluted with a solvent or the like having the optimum concentration for each coater.

[0010] Printed materials include polyester films, polyethylene films, polypropylene films,
Plastic films such as nylon films and mirrors
Coated paper, synthetic paper (polypropylene base, vinyl chloride base, etc.), plain paper and the like are used.

A liquid toner for developing an electrostatic charge for forming an image layer
There is no particular limitation, and conventionally known toner particles dispersed in water and / or an organic solvent can be used. Generally, the toner particles comprise a fixing resin for fixing the toner particles to the printing medium, a coloring agent for visualizing the toner particles, and a charge controlling agent for adjusting the electric characteristics of the liquid toner. .

As the fixing resin, known resins conventionally used in liquid toners for electrostatic charge development can be used, and thermoplastic resins are particularly preferable. For example, polystyrene, styrene-acrylic acid copolymer , Polyacrylic acid, polyethylene, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, polypropylene, polyester, polyurethane, polyamide, etc. can be used alone or as a mixture.

As the coloring agent, known pigments and / or dyes conventionally used in liquid toners for electrostatic charge development can be used. Examples of the coloring agent include Hansaero, benzidineero, benzidine orange, fast red, brilliant carmine 3B, copper phthalocyanine bull, phthalocyanine rin, spirit black, oil bull, alkali bull, and rhodamine. 6B, nigrosine, carbon plaque, dichloroquinacridone, isoindoline, titanium oxide and the like.

Examples of the charge control agent include metal salts of fatty acids such as naphthenic acid, octenoic acid, oleic acid and stearic acid;
Known charge control agents such as metal salts of sulfosuccinates, nonionic surfactants such as polyoxyethylated alkylamines, oils and fats such as lecithin and linseed oil, polyvinylpyrrolidone and organic acid esters of polyhydric alcohols. Can all be used.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. In the examples, “part” indicates “part by weight” and “%” indicates “% by weight”.

Example 1 An aqueous solution of an ethylene-acrylic acid resin ("Sixensen AC" manufactured by Sumitomo Seika Co., Ltd., weight average molecular weight: 20,000, resin solid content: 30%) was mixed with water / isopropyl alcohol = 1/1 (weight ratio). Resin solid component 5 with mixed liquid
% To prepare a primer. The obtained primer was placed on a treated polyethylene film having a thickness of 40 μm.
It was applied to a thickness of 0.5 μm (dry film) using a gravure coater and dried. Then, on the primer layer, a liquid developed electrophotographic copier (“Sebin 8” manufactured by Sebin, USA) was used.
70 ") to obtain a clear printed matter.

Example 2 A clear printed matter was obtained in the same manner as in Example 1 except that the treated polyethylene film having a thickness of 40 μm was replaced with a 110 μm-thick mirror-coated paper (manufactured by Kanzaki Paper). .

Example 3 An aqueous polybutadiene resin solution ("Adcoat EL451" manufactured by Toyo Motor Corporation, weight average molecular weight: 8,000, resin solid content: 10%) was mixed with water / isopropyl alcohol = 1/1 (weight ratio). ) A primer was prepared by diluting the mixed solution to 2% of the solid resin content, and then applied to a treated polyethylene film having a thickness of 40 µm and dried in the same manner as in Example 1. Then, on the primer layer, a liquid developed electrophotographic copier (“Sebin 8” manufactured by Sebin, USA) was used.
70 ") to obtain a clear printed matter.

Example 4 A clear printed product was obtained in the same manner as in Example 3 except that the treated polyethylene film having a thickness of 40 μm was replaced with a 110 μm-thick mirror-coated paper (manufactured by Kanzaki Paper). .

Example 5 The same primer as in Example 1 was applied on a treated polyethylene film having a thickness of 40 μm using a gravure coater to a thickness of 0.01 μm (dry film) and dried. did. Then, on the primer layer, a liquid developed electrophotographic copier (“Sebin 8” manufactured by Sebin, USA) was used.
70 ") to obtain a clear printed matter.

Example 6 The same primer as in Example 1 was applied on a treated polyethylene film having a thickness of 40 μm to a thickness of 1.3 μm (dry film) using a gravure coater and dried. did. Then, on the primer layer, a liquid developing electrophotographic copying machine (“Sebin 87” manufactured by Sebin, USA) was used.
0 "), and a clear printed matter was obtained.

Comparative Example 1 An image was output on a polyethylene film treated with a thickness of 40 μm using a liquid developing electrophotographic copying machine (“Sebin 870” manufactured by Sebin, USA). Was poor in fixing, and no clear printed matter was obtained.

Comparative Example 2 Image output on a 110 μm-thick mirror-coated paper (manufactured by Kanzaki Paper Co., Ltd.) using a liquid developing electrophotographic copier (“Sebin 870” manufactured by Cevin, USA). And a clear printed matter was obtained.

The prints obtained in the examples and comparative examples were evaluated for fixability, adhesiveness, and blocking resistance of the primer portion as follows. Table 1 shows the results. Fixing property: The reflection density of the obtained image was measured by a reflection densitometer ("Macbeth RZ918" manufactured by Macbeth). The larger the value, the better the fixing property. Adhesiveness: The degree of peeling of the printed film with a 12 mm cellophane tape (Nichiban “Cellotape”) was visually evaluated,
Expressed in five levels. 5: Does not peel even if it is rapidly separated. 4: Midway between 3 and 5. 3: Separation occurs when detached rapidly, but does not occur when detached gradually. Between 2: 1 and 3. 1: Peeling off even when gradually separated.

The blocking resistance of the primer portion: The primer surfaces were overlapped, left under a load of 500 g / cm ² at 40 ° C. for 24 hours, peeled off, and the appearance of the primer portion film was visually evaluated. , Expressed in five stages. 5: No peeling resistance, no change in the film. 4: There is some peeling resistance, but no change occurs in the film. 3: The film is slightly peeled. 2: The film is considerably peeled. 1: Completely adhered, and peeling occurred on the entire surface of the film.

[0026]

[Table 1]

[0027]

According to the present invention, a liquid toner for electrostatic charge development is provided.
Was used as an image forming material, and the adhesion, friction resistance, water resistance, and the like of the toner were improved when plastic and paper were used as the printing medium.

Claims (2)

[Claims] 1. A printed material obtained by sequentially forming a primer layer made of an ethylene / acrylic acid-based resin or a polybutadiene-based resin and an image layer formed by an electrostatic liquid developing method on a printing medium. 2. The primer layer has a thickness of 0.01 to 5.0 .mu.m.
The printed matter according to claim 1, wherein m is m.