JPH0651537A - Electrostatic recording body - Google Patents

Abstract

PURPOSE:To obtain a clear image free from the generation of line cut or abnormal discharge by pressing to flatten a pigment exposed on the surface of a recording layer by the use of a smooth metallic face. CONSTITUTION:A dielectric recording layer 3 is formed by applying a dielectric recording layer forming solution on an electroconductive substrate 4. The surface of the recording layer 3 is pressed by the use of the smooth metallic face. The recording layer 3 is an insulating layer to hold a latent image charge and mainly contains an insulating resin and a pigment. The ratio of the resin to the pigment in the recording layer is (6:4)-(4:6). The smooth metal to press the recording layer 3 is harder than the pigment used in the recording layer 3 and the surface is preferably a surface finished by mechanical way such as grinding. Concretely by using a super calender, the recording surface is processed so as to be pressed by the use of a metallic roller. And the surface of the pressed recording layer 3 has 50-200 seconds smoothness in Bekk smoothness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CAD (Computer Aided Design) using an electrostatic recording system.
n), an electrostatic recording material for CG (Computer Graphics).

[0002]

2. Description of the Related Art Since an electrostatic recording method using a multi-needle electrode is capable of outputting a recorded image at a wide width and at a high speed, it has been used in a wide range of industrial fields together with the progress of CAD technology such as design using a computer. .

By the way, the electrostatic recording method using a multi-needle electrode is capable of high-density recording such as a recording density of 400 dots / inch, but the needle diameter is smaller than that of the conventional 200 dots / inch, and the discharge area is large. There are problems such as line breakage (dot omission) when drawing a fine line, abnormal discharge (abnormal dot), etc., probably because the number of lines is reduced.

In order to improve the recording quality, it is effective to improve the insulating property of the pigment used in the recording layer. For example, kaolin surface-treated with styrene or
Method using kaolin and aluminum hydroxide calcined at high temperature (JP-A-2-248958, JP-A-2-2-2)
No. 50060, Japanese Patent Laid-Open No. 4-9957) and the like are proposed.

There is no known example of pressurizing the recording surface after forming the recording layer as shown in the present invention.

[0006]

According to the prior art, in order to improve the insulating property of the pigment used in the recording layer, there are those which are coated with a high resistance resin and which are baked at a high temperature, but these are coated. The amount of resin and the firing conditions influence the quality, and in reality, it is difficult to control these conditions and it is difficult to obtain stable quality.

Further, there are drawbacks such as an increase in the number of manufacturing steps and an expensive product.

The present invention intends to provide an electrostatic recording material used in a high-density electrostatic recording system such as 400 dots / inch, which can obtain a clear image without line breakage or abnormal discharge. It is a thing.

[0009]

According to the research conducted by the present inventors, most of the causes of line breakage and abnormal discharge are caused by large pigment particles or pigments exposed more than the surface of the recording layer. It was found that insufficient or locally excessive discharge occurred due to failure to obtain a proper discharge gap with the recording needle, resulting in line breakage and abnormal discharge.

Therefore, in order to suppress the occurrence of line breakage and abnormal discharge, investigations have been made for improvement by keeping the distance between the recording needle and the surface of the recording layer within an appropriate range.

As a result, the inventors have found that the pigment exposed on the surface of the recording layer is pressed and crushed by a smooth metal surface to drastically reduce line breakage and abnormal discharge. is there.

That is, the constitution of the present invention is an electrostatic recording body as set forth in the claims. The smooth metal for pressure-treating the recording layer used in the present invention is harder than the pigment used in the recording layer, and the surface thereof is preferably mechanically polished and finished.

As a concrete means, a generally used super calender may be used so that the recording surface is pressed by a metal roller.

The Beck's smoothness of the surface of the pressure-treated recording layer is preferably 50 to 200 seconds, and if the smoothness is less than that, line breakage and abnormal discharge cannot be sufficiently improved. On the other hand, if the time exceeds 200 seconds, unevenness of the image occurs, and especially non-uniformity of the solid portion occurs.

Regarding the ratio of the resin and the pigment used in the recording layer, if the ratio of the resin is increased, a high image density can be obtained, but the smoothness after the pressure treatment of the recording surface with a smooth metal tends to be high. It becomes difficult to adjust the smoothness depending on the pressurizing condition.

On the contrary, if the proportion of the pigment is increased, the smoothness is prevented from increasing due to the pressure treatment, and the smoothness can be easily adjusted, but a problem such as a decrease in image density occurs.

In order to prevent the occurrence of such a problem, the ratio of resin and pigment in the recording layer is set to resin: pigment = 6: 4.
This is solved by setting the ratio within the range of to 4: 6, whereby an electrostatic recording material in which line breakage and abnormal discharge hardly occur can be easily obtained.

1, 2 and 3 show three typical examples of the electrostatic recording body of the present invention. That is, FIG. 1 shows that the recording layer 3 is provided on the surface of the conductive substrate 4, and FIG. 2 shows that the conductive layers 21 and 22 are provided on both front and back surfaces of the substrate 1 and the recording layer 3 is provided on the conductive layer 21. In FIG. 3, conductive layers 21 and 22 are provided on both front and back surfaces of the conductive substrate 4, and the recording layer 3 is provided on the conductive layer 21.

The substrate 1 and the conductive layers 21 and 22 in the present invention
The conductive substrate 4 and the conductive substrate 4 are conventionally used or known in the field of electrostatic recording media. For example, base 1
For, plain paper and transparent paper are used.

As the conductive agent used for the conductive layers 21 and 22, polyethyleneimine hydrochloride, poly (2-metalloyl-oxyethyltrimethylammonium chloride), poly (2-hydroxy-3-methacryloyloxypropyltrimethylammonium chloride). , Quaternary ammonium salts such as poly (N-acrylamidopropyl-3-trimethylammonium chloride), poly (N, N-dimethyl-3,5-methylenepiperidinium chloride), polydimethyldiallylammonium chloride and polyvinyltrimethylammonium chloride. Cations such as sulfonium salts such as poly (2-acryloxyethyldimethylsulfonium chloride) and phosphonium salts such as poly (glycidyltributylphosphonium chloride) Conductive agents, polymethacrylic acid carboxylates, polyacrylic acid carboxylates, polystyrene sulfonate, organic polymer electrolytes of anionic conductive agents such as polyvinyl sulfonate, and transparent inorganic conductive materials such as conductive tin oxide, but these It is not limited to.

As the pigment, clay, calcium carbonate,
Silica, silicon dioxide, etc. are used.

As the binder, polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose,
Carboxymethylcellulose salts, styrene-maleic acid copolymer salts, polyelectrolytes such as polyvinylbenzyltrimethylammonium chloride, and in the case of aqueous emulsion type, for example, polyvinyl acetate, acrylic resin, styrene-butadiene copolymer. , Vinyl chloride-vinyl acetate copolymer and the like.

The recording layer in the present invention is an insulating layer that retains latent image charges, and has an insulating resin as a main component and has practical properties such as matting, writability, and imprintability of the recording layer surface. For this purpose, auxiliary components are added.

Examples of the insulating resin include alkyd resin, silicone resin, epoxy resin, polystyrene resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, styrene-butadiene copolymer resin, polybutyral resin, saturated or An unsaturated polyester resin, acrylic acid-based resin, methacrylic acid-based resin or the like is used.

Examples of auxiliary components include oxides and hydroxides such as zinc, titanium, magnesium, calcium and aluminum, carbonates or sulfates, and inorganic powders such as silica, alumina, bentonite and kaolin.

In addition to these, a polycarbonate resin, vinylidene chloride resin, or the like may be deposited as a gel in an insulating resin.

The recording layer forming liquid is prepared using a disperser such as an attritor, a ball mill, a homomixer and a grain mill, and is applied with a bar coater, a doctor coater or the like.

[0028]

EXAMPLES Examples will be described below, but the invention is not limited thereto. The amounts (parts) of the components described in the examples are by weight.

Example 1 (Preparation of Conductive Support) ^On a wood free paper having a basis weight of 55 g / m ² ,
A conductive layer liquid composed of the following materials was applied on the front and back by a dry weight of 6 g / m ² each and smoothed by a super calender to obtain a conductive support.

Clay 6 parts Conducting agent (Chemist 6300 manufactured by Sanyo Kasei Co., Ltd.) 12 parts Water 23 parts (Preparation of electrostatic recording body) Recording layer liquid (resin: pigment = 7: 3) was dispersed with an attritor, applied with a wire bar to a dry weight of 6 g / m ^2, and dried in an oven at 110 ° C. for 10 minutes.

Thereafter, the humidity was adjusted for 4 hours in an environment of 20 ° C. and 60%, and then pressure treatment was carried out by a calender to make the smoothness of the recording layer 20
An electrostatic recording medium of 0 seconds was obtained.

In order to suppress the smoothness within 200 seconds, an extremely low pressure treatment was required.

(Composition of Recording Layer Liquid) Acrylic copolymer resin (solid content 40%) 17.5 parts Calcium carbonate (average particle diameter 3.5 μ) 3 parts Toluene 13 parts Example 2 Recording layer liquid described below ( An electrostatic recording material was obtained in the same manner as in Example 1 except that the resin: pigment = 3: 7) was used.

The smoothness can be easily adjusted by the pressure of the calendering process, and an electrostatic recording body having a smoothness of 70 seconds was produced.

(Composition of Recording Layer Liquid) Acrylic copolymer resin (solid content 40%) 7.5 parts Calcium carbonate (average particle size 3.5 μ) 7 parts Toluene 19 parts Example 3 The recording layer liquid is described below. Recording layer liquid (resin: pigment = 6:
An electrostatic recording body was obtained in the same manner as in Example 1 except that the above procedure was changed to 4).

The smoothness can be easily adjusted by the pressure of the calendering process, and an electrostatic recording material having a smoothness of 120 seconds was produced.

(Composition of Recording Layer Liquid) Acrylic copolymer resin (solid content 40%) 15 parts Calcium carbonate (average particle diameter 3.5 μ) 4 parts Toluene 15 parts Example 4 Recording layer liquid described below. Liquid (resin: pigment = 4:
An electrostatic recording body was obtained in the same manner as in Example 1 except that the above method was changed to 6).

The smoothness can be easily adjusted by the pressure of the calendering process, and an electrostatic recording material having a smoothness of 110 seconds was produced.

(Composition of Recording Layer Liquid) Acrylic copolymer resin (solid content 40%) 10 parts Calcium carbonate (average particle size 3.5 μ) 6 parts Toluene 17 parts Comparative Example 1 In Example 3, no calender treatment was carried out. The thing was produced as a conventional electrostatic recording body. The smoothness of the recording layer was adjusted to 110 seconds by adjusting the dispersion time of the attritor. Comparative Example 2 In Example 4, a material not subjected to the calender treatment was prepared as a conventional electrostatic recording body. The smoothness of the recording layer was adjusted to 80 seconds by adjusting the dispersion time of the attritor.

The six types of electrostatic recording media thus obtained were
Toyo Denki Seisakusho's Electrostatic Plotter Drastem D86
The image was evaluated with the numeral 00.

The evaluation results are shown in Table 1.

[0042]

[Table 1]

The evaluation criteria are as follows.

Line break: The number of lines broken per 40 cm of a 2-dot diagonal line.

Abnormal discharge: The number of abnormal dots of 0.2 mm or more generated per 40 cm of a 2-dot diagonal line.

Image density: A value obtained by measuring a black pattern portion with a Macbeth densitometer.

Solid Uniformity: Visually evaluated, and the results are as follows.

◎ ・ ・ ・ ○ ・ ・ ・ △ ・ ・ ・ × Excellent Excellent Inferior

[0049]

As is apparent from the above embodiments, the electrostatic recording material of the present invention is an electrostatic recording material in which line breakage and abnormal discharge, which have been problems in the past, are dramatically improved.

[Brief description of drawings]

[Figure 1]

[Fig. 2]

FIG. 3 is a schematic cross-sectional view for explaining the configuration of each specific example of the electrostatic recording body of the present invention.

[Explanation of symbols]

 1 Substrate 21 Conductive Layer 22 Conductive Layer 3 Dielectric Recording Layer 4 Conductive Substrate

Claims (2)

[Claims] 1. A dielectric recording layer forming liquid containing an insulating resin and a pigment as main components is applied onto a conductive support, and then the surface of the dielectric recording layer is pressure-treated with a smooth metal surface. The electrostatic recording material is characterized in that the Beck smoothness is in the range of 50 to 200 seconds. 2. The electrostatic recording body according to claim 1, wherein the weight ratio of the insulating resin and the pigment in the dielectric recording layer is in the range of resin: pigment = 6: 4 to 4: 6.