JPH0683075A - Electrostatic recording body - Google Patents

Abstract

PURPOSE:To provide an electrostatic recording body having such excellent image characteristics as to give a satisfactory image especially even at high humidity and to ensure stable high precision image quality under various environmental conditions. CONSTITUTION:When an electric conductive layer and a recording layer are successively laminated on a substrate to obtain an electrostatic recording body, silicone resin particles are incorporated into the recording layer. A resin used can be selected among various resins each having function as the dielectric layer of the electrostatic recording body, soluble in an org. solvent and having high insulation resistance, e.g. polyester, polycarbonate and polyamide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic recording material, and more particularly to an electrostatic recording material capable of obtaining a high definition image.

[0002]

2. Description of the Related Art Conventionally, an electrostatic recording method using an electrostatic recording medium has been used in various fields such as facsimile, drafting, newspaper proofreading, and official document recording. In recent years, C
With the development of AD and CAM, the electrostatic recording method is used for the recording apparatus, and its application is rapidly expanded with the development of the electrostatic recording type color recording-compatible apparatus. It is becoming more popular in the fields related to advertising because color copies can be easily obtained. Due to such a background, higher definition images are required for these applications as compared with those for facsimiles, and also for color images, higher definition images that are more precise and faithful to the original image are required.

However, the recording layer in the conventional electrostatic recording medium is formed of silica, polyester, polymethacrylic acid ester, polyvinyl acetate or the like in a binder having a high dielectric constant in order to improve air discharge characteristics. , Clay, alumina, calcium carbonate and other inorganic pigments are dispersed. That is, the conventional electrostatic recording material is poor in moisture resistance because it contains a pigment component, and when recording in a high humidity atmosphere, there is a problem that image density is low or image bleeding occurs. In addition, since the particle size of the inorganic pigment used is not taken into consideration, there is a problem that the wide particle size distribution causes image uniformity and image dropout. Therefore, the electrostatic recording material satisfying the demand for high-definition images as described above has not yet been obtained.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides an electrostatic recording material having high definition and excellent image characteristics under a wide range of environmental conditions.

[0005]

The present invention provides an electrostatic recording body comprising a support and a conductive layer and a recording layer sequentially laminated on the support, wherein the recording layer contains silicone resin particles. It is an electronic recording body. The silicone resin particles used in the present invention are not particularly limited as long as they are resin particles containing organopolysiloxane having a three-dimensional network structure as a main component. As such silicone resin particles, for example, those having a structure in which one methyl group is bonded to a silicon atom are preferable because they have excellent solvent resistance and heat resistance. Specifically, Toshiba Silicone Co., Ltd. More-marketed Tospearl 103, 105, 108, 1
20, 130, 145, 3120, 240 (each of which is a trade name) and the like.

In the present invention, the particle size of the silicone resin particles is not particularly limited, but is 0.3 to 12 μm.
Particles are suitable, and 0.5 to 5 μm is particularly preferable. Here, it is preferable that the particle size distribution is as uniform as possible, but it is not necessary to consider the particle size distribution for particles having a particle size of 12 μm or less. If particles having a particle size of more than 12 μm are used, the image dropout tends to occur, and the uniformity of the image may be impaired.

In the present invention, the silicone resin particles as described above are preferably contained in the recording layer in an amount of 0.4 to 45% by weight. If the addition amount of the silicone resin particles exceeds 45% by weight, the problem that the density of the recorded image cannot be sufficiently obtained may occur, whereas if it is less than 0.4% by weight, good air discharge characteristics can be obtained. However, problems such as image unevenness and image loss may occur.

The recording layer in the present invention has a constitution in which the silicone resin particles are contained in the resin. Here, as the resin, various kinds of organic solvent-soluble resins having a large insulation resistance that function as a dielectric layer of an electrostatic recording medium can be used, and examples thereof include polyester, polycarbonate, polyamide, polyurethane, and (meth) acrylic resin, Examples thereof include styrene resin, olefin resin, silicone resin, fluororesin and the like. In addition, if necessary, in order to improve the writability and the like, an inorganic pigment or an organic pigment, which will be described later, used in the conductive layer can be used within a range that does not impair the effect of the silicone resin particles.

For the conductive layer in the present invention, many known conductive materials such as ion conductive materials and electron conductive materials can be applied. For example, a cationic or anionic polyelectrolyte is the main component, and if necessary, silica, aluminum hydroxide, aluminum oxide, kaolin, talc, mica, calcium carbonate, calcium sulfate, inorganic pigments such as zeolite, cellulose powder, polyethylene. Powder, polypropylene powder and other organic pigments, starch, polyvinyl alcohol and other water-soluble polymers, polyester, (meth) acrylic, styrene, urethane,
Using various resins such as rubber, epoxy, and melamine as binders, carbon black, graphite, tin oxide, titanium oxide, zinc oxide, antimony oxide, gold, silver,
A dispersion of conductive fine powder such as copper or nickel, and
A metal vapor deposition film formed of gold, aluminum, platinum, indium, tin, palladium-platinum, tin-antimony oxide or the like by a method such as vacuum deposition or sputtering can be used as the conductive layer. The surface resistance of the conductive layer is preferably 1.0 × 10 ^{5 to} 1.0 × 10 ⁹ Ω.

As the support in the present invention, for example, paper, synthetic paper, non-woven fabric, various resin films, cloth, leather and the like can be used without any particular limitation. The electrostatic recording medium of the present invention is produced by sequentially laminating the above-mentioned conductive layer and recording layer on at least one surface of the support as described above. To provide a conductive layer and a recording layer, respectively, a suitable solvent as necessary, for example, water, methanol, ethanol, toluene, acetone, methyl ethyl ketone, a paint prepared by dissolving or dispersing the above materials in ethyl acetate, an air knife coater, It can be provided by coating and drying with a roll coater, wire bar coater, spray coater, fountain coater, reverse roll coater, or the like.

In the electrostatic recording medium of the present invention, a barrier layer may be provided between the support and the conductive layer or on the back surface of the support, if desired. The barrier layer includes, for example, a styrene-butadiene copolymer, an acrylic-acrylic acid ester copolymer, a styrene-acrylic copolymer, a vinyl acetate-acrylic copolymer, a vinyl chloride resin, a vinyl chloride-vinyl acetate copolymer, and the like. Various emulsion resins are preferable, but various known resins are used without being limited thereto. Inorganic pigments, organic pigments, and conductive pigments used for the conductive layer can be used as necessary.

[0012]

EXAMPLES Next, examples will be described in detail. In addition, all the parts showing the composition represent parts by weight. Example 1 A high-quality paper having a basis weight of 50 g / m ² was used as a support, and a conductive layer coating material having the following composition was applied to one surface of the support and dried to form a conductive layer having a coating amount of 10 g / m ^2. Provided. This was calendered so that the electroconductive layer had a smoothness of 400 to 500 seconds using an Oken smoothness meter. -Conductive zinc oxide (23-K manufactured by Hakusui Chemical Co., Ltd.) 100 parts-Polyvinyl alcohol (PVA105 manufactured by Kuraray Co., Ltd.) 10 parts-Water 190 parts On the conductive layer of the above-mentioned support, a recording layer coating material having the following composition was used. After coating and drying, a recording layer having a coating amount of 4 g / m ² was provided to prepare an electrostatic recording body of the present invention. -Linear polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd., solid content 40%) 480 parts-Silicone resin particles (Tospar 130 manufactured by Toshiba Silicone Co., particle size 3 µm) 6 parts-Toluene 170 parts

Example 2 An electrostatic recording material of the present invention was prepared in exactly the same manner as in Example 1 except that a recording layer coating material having the following composition was used. -Linear polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd., solid content 40%) 350 parts-Silicone resin particles (Tospar 130 manufactured by Toshiba Silicone Co., particle size 3 μm) 60 parts-Toluene 240 parts Comparative Example 1 For recording layer having the following composition Example 1 except that a paint was used
An electrostatic recording material for comparison was prepared in exactly the same manner as. -Linear polyester resin (Byron 200 manufactured by Toyobo Co., Ltd., solid content 40%) 450 parts-Calcium carbonate (Softon 1200 manufactured by Bihoku Powder Co., Ltd.) 20 parts-Toluene 200 parts

With respect to the electrostatic recording bodies of Examples 1 and 2 and Comparative Example 1 produced above, an electrostatic facsimile (NEFAX 702 manufactured by NEC Corporation) was used and environmental conditions of 30 ° C. 3
Images were formed at 0% RH, 20 ° C. 60% RH, and 30 ° C. 80% RH, and the obtained images were evaluated. The evaluation was carried out by measuring the image density using a Macbeth reflection densitometer RD-914, and the image quality was visually evaluated as follows. Those having a problem in practical use because they were found to be considerably defective were marked with x.

[Table 1] The image evaluation results are shown in Table 1, and it was confirmed that the electrostatic recording medium of the present invention has excellent image characteristics.

[0015]

EFFECTS OF THE INVENTION The electrostatic recording material of the present invention contains a silicone resin particle in the recording layer, so that a good image can be obtained even under a high humidity condition and a stable and high-definition image quality can be obtained over a wide range of environmental conditions. That is, it has excellent image characteristics.

Claims (1)

[Claims] 1. An electrostatic recording body comprising a support and a conductive layer and a recording layer sequentially laminated on the support, wherein the recording layer contains silicone resin particles.