JPS60181747A - Electrostatic recording material - Google Patents

Abstract

PURPOSE:To obtain an electrostatic record high in resolution by forming a dielectric layer composed of a pigment specified in particle diameter, and at least 2 kinds of dielectric resins soluble in the same solvent on a conductive substrate. CONSTITUTION:A dielectric layer 3 contg. >=2 kinds of dielectric resins soluble in the same solvent and a pigment having an average particle diameter of <=2mum is laminated on a conductive layer 4 formed on a conductive substrate 5. The layer 4 is coated with a coating material contg. said components of the layer 3 and in the stage of drying it, microphase separation occurs and the surface of the layer 3 having protuberances 1 due to the microphase separation and those 2 due to the pigment particles is formed. These protuberances 1, 2 on the layer 3 permit discharge from a recording electrode to occur securely and a good image free from dropout of thin lines and large dots to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrostatic recording electrode, and is particularly suitable for electrostatic recording, which is used frequently and which has recently begun to be used in facsimiles and printers. The purpose of this invention is to provide a recording medium with

(Prior Art) Electrostatic recording has excellent recording speed and record storage stability, and is widely used in the fields of facsimiles and printers. Also, recently, a recording electrode with a high resolution of 16 dots/wm has been developed, and it has a feature superior to recording methods such as thermal recording in terms of M image resolution. On the other hand, with the development of HumPyCoo, CAD (Qyrputer Aided Dealing) has been introduced, which allows HoP computers to design drawings of machinery, buildings, etc., and outputs the results to PenPlottani.
n) Although the technology has been developed, it takes several minutes to 10 minutes or more for complicated drawings, and there is a problem in terms of work efficiency.

Also, there is a problem with the thickness of the pen tip, which is around 0.1 +ft1.
l#! It was difficult to draw.

In order to solve this problem, efforts have been made to use the above-mentioned electrostatic recording electrode with high WI image resolution for CAD drawing.
When plotting with a recording electrode of 6 dots/m, dot reproducibility is a problem. In other words, conventional 4~Q do
When recording paper, which had been well recorded by electrostatic recording with a resolution of ts, %mm, was recorded with a machine of 1 5 dots/1 urn, it had the disadvantage that thin lines were missing and the lines were broken. Conventionally, this is the diameter force of the recording needle for electrostatic recording.
whereas it is 0-100μ or more.

In the case of 16 dots/w, the diameter of the recording needle is approximately 40μ
The contact area between one Trt pole and the recording paper has decreased, and the voltage application time has been reduced from 10 to several microseconds.
It is long, several hundred microseconds, and the applied voltage is -600 to -800V.
On the other hand, in the case of 16 dotg/mm, the application time was as short as 10 μ seconds (and the voltage was also low at -560 V, which were both negative factors, resulting in less energy being emitted between the recording needle and the surface of the recording paper. If this occurs, it is thought that fine line dropout will occur.It is necessary to provide an appropriate gap between the recording needle and the surface of the dielectric layer to ensure the movement of the 1σ charge. It is well known (IBM Jour
nal 192 April 1962), and a recording needle with a diameter of 401t was used to print the D voltage -560V,
In order to reliably record with pulses of 10 microseconds or less, it is necessary to use recording paper with smaller protrusions on the surface of the dielectric layer than the conventional recording paper that provides good recording quality at 4 to 8 dat8/-m. Conceivable. However, in this case, recording reliability is increased and thin line omissions are improved, but on the contrary, giant dots, which are thought to be caused by abnormal discharge, are generated, and the density of the dots is uneven, resulting in uniform recording of solid i and 8 records. The disadvantage is that the sex deteriorates.

(Object of the invention) The present invention solves the above-mentioned drawbacks,
Even in electrostatic recording that requires high resolution, such as electrostatic recording using a recording electrode of There is.

(Construction of the Invention) The present invention provides an electrostatic recording material comprising an electrically conductive support and a dielectric layer provided on the electrically conductive support, in which the dielectric layer contains pigments having an average particle size of 2 μm or less, The electrostatic recording material is made of at least two kinds of dielectric resins selected from dielectric resins that are soluble in a solvent.

(Detailed Description of the Invention) The present invention involves coating a dielectric layer paint containing two or more types of dielectric resins and a pigment with an average particle size of 2μ or less on a conductive layer, and causing microphase separation during the drying process. This is achieved by causing a dielectric layer surface to have protrusions due to phase separation and protrusions due to pigment particles.

DT obtained by the present invention! A layer surface cannot be obtained by simply mixing a pigment and one type of dielectric resin. In other words, an electrostatic recording material having a dielectric layer obtained by mixing various pigments with different average particle sizes and one type of dielectric resin cannot produce a consistent record, but when pigments with an average particle size of 2 μ or less Good recording can be obtained with an electrostatic recording material having a dielectric layer obtained by mixing two or more types of dielectric resins. The dielectric WJW resin can be used as long as it dissolves in the same solvent and mixes uniformly in a solution state, but it is better to use one that does not dissolve.

Hereinafter, the structure of the present invention will be explained based on the drawings illustrating the structure, and FIG. 1 is a cross-sectional view of the electrostatic recording material of the present invention.
Protrusions on the surface of 5vLi are formed from the protrusions 5 formed by the pigment particles and the protrusions 2 formed by the pigment particles.

FIG. 2 is a sectional view of a conventional electrostatic recording material made of a pigment and one type of dielectric resin, and there are no projections 2a, 2bL formed by pigment particles on the surface of the dielectric layer.

In the case of the recording paper having the dielectric layer surface shown in FIG. Because of the presence of the small protrusion 2, discharge is reliably performed from the fl electrode to the surface of the protrusion 20,
It is thought that a good record without the occurrence of thin lines missing or giant dots can be obtained.

In the case of the surface of the U conductive layer shown in FIG. 2, a gap between the recording layer surface and the recording electrode is maintained by projections 2a made of relatively large diameter pigment particles, and projections 2b and a flat surface made of small particles between the gaps are maintained. A discharge occurs from the recording electrode K11i2 on the surface of the dielectric TrL layer, but the probability of discharge is low (only recording with thin lines missing is obtained. This is thought to be due to the small number of protrusions formed by small particles.

In order to increase the number of small particles, it is possible to use a pigment with a small average particle size, but in this case, the projections due to large particles in the pigment will also become smaller, and the distance t of the recording electrode (t should be kept at about 3 to 10μ). This makes it impossible to obtain good records.

First, materials that can be used in the present invention will be explained.

Supports include paper and plastic film.

The present invention can be satisfied even if various supports conventionally used as supports for electrostatic recording materials are used, such as polyester film, polypropylene film, polyethylene film, and synthetic paper.

Examples of the conductive agent include cation; f, conductive resin 9, and quaternary ammonium salts such as polyvinylbenzyltrimethylammonium chloride, polydimethyldiallylammonium chloride, and styrene acrylic acid trimethylammonium chloride.

In addition to anionic conductive resins 9 such as polystine sulfonate, polyacrylic acid, and polyvinylphosphonate, gold halide semiconductors such as zinc oxide, gold powder, organic or inorganic salts, and surface active Agents may be used alone or in combination.

A conductor formed by coating or impregnating the above conductive agent alone on a support, or by coating or impregnating a mixture of a pigment such as calcium carbonate clay and a water-soluble or water-dispersible adhesive on a support. NM satisfies the present invention.

Dielectric resins include vinyl acetate resin, ethylene-vinyl acetate copolymer resin, vinyl chloride resin, and vinyl chloride.

Vinyl acetate copolymer resin, vinylidene chloride resin, vinyl chloride, vinylidene chloride copolymer resin/acrylic acid ester resin, methacrylic acid ester resin, butyral resin, polyester resin, vinylidene fluoride [i, 2) Cellulose resin, styrene resin Resins such as styrene and acrylic copolymer resins can be used.

Most resins with a pot resistance of 1012 Ω and cIn or higher can be used, but among these resins, at least one selected from U-electric resins that can be dissolved in the same solvent and can be mixed uniformly in a solution state can be used. The present invention is satisfied by selecting and using two types of dielectric resins.

For example, vinyl acetate resin/nitrocellulose ψjB,
Acrylic ester resin/nitrocellulose resin, ethylene vinyl acetate copolymer resin/nitrocellulose resin, vinyl chloride resin/ethylene vinyl acetate copolymer resin, acrylic ester resin/vinyl acetate resin.

21 such as acrylic ester resin/vinyl chloride vinyl acetate copolymer resin, acrylic ester resin/styrene resin, etc.
It is a mixed system of type 1i resins, a mixed system of three types of resins such as styrene resin/methacrylic acid ester resin/styrene acrylic copolymer resin, and vinylidene fluoride resin/methacrylic acid ester resin/styrene acrylic copolymer resin.

Pigments include calcium carbonate, clay, calcined rhea talc, chigun oxide, lithopone, barium sulfate, silicic acid, zinc oxide, and epoxy resin powder.

Among melamine resin powder, urea resin powder, polyethylene resin powder, polypropylene resin powder, etc., the average particle size is 2μ
The following can be used:

The dielectric resin and pigment are mixed at a ratio of 40:so to 90:10, and the M shell after drying is 30 to 10.0 f/n.
? A g-conductor layer is formed by applying the following.

The present invention will be described in more detail below with reference to Examples. One part on each side indicates parts by weight.

Example 1 Basis weight 52.3 f/lT? high-quality paper (product name: Sunflower).

Conductive resin (Chemistat (+3
00+manufactured by Sanyo Chemical Co., Ltd.) was applied so that the weight after drying was 3.0%, and smoothing treatment was performed using a super calender to obtain a conductive support having a Bekk smoothness of 200 seconds.

A di-layer paint having the following composition ratio was dispersed in a paint conditioner for 10 minutes, and the weight after drying was 6, Of/n?
An electrostatic recording material was obtained by coating on the conductive layer so as to obtain the following.

Acrylic resin (LR349, manufactured by Mitsubishi Rayon [I44 parts 40%) 75 parts Vinyl chloride vinyl acetate copolymer resin (LC8, manufactured by H Tomari Kagaku, solid content 36%) 83 parts Calcium carbonate (MS-600, average grain manufactured by Nitto Funka Co., Ltd.) Diameter 1
, 5μ) 40 parts Toluene 68 parts Ethyl acetate 68 parts This electrostatic recording material was subjected to humidity conditioning at 25° C. and 45% RH for 4 hours, and then recording was performed. The recording was done using a commercially available 16 dots/+m.
Pin electrode K of multi-stylus electrode with same plane control method of n -280V 5 #Second control electrode K +280V
Using an electrode adjusted so that a pulse voltage of 1071 seconds could be applied, recording evaluation was performed by developing with a stop-static liquid toner after applying the voltage. A voltage was applied to one bottle electrode to evaluate fine bond omissions and giant dots, and a voltage was applied to all the forceps electrodes to evaluate the uniformity of the recording. The results are shown in Table 1, and the wound opening, giant dots, and uniformity were all good. In addition, when the surface of this recording material was observed using a scanning electron microscope, small protrusions thought to be caused by pigment particles and relatively large protrusions thought to be caused by phase separation of the resin were observed.

Example 2 Comparative Example 1 fA#i Instead of calcium carbonate in Example 1, average particle size 1.1
When calcium carbonate with a particle diameter of 2.6μ is used...Example 2 When calcium carbonate with an average particle size of 2.6μ is used...Comparative Example 1. Except for this, an electrostatic recording medium was produced in the same manner as in Example 1, and a recording test was conducted. The results are shown in Table 1.

This result shows that good recording quality can be obtained when a pigment with an average particle size of 2 μm or less is used.

Comparative example 2 75 parts of the acrylic resin of Example 1 and vinyl chloride.

'I'F except that 83 parts of vinyl acetate resin was replaced with vinyl chloride and vinyl acetate resin so that the solid content was the same.
An electrostatic recording medium was prepared in the same manner as in Example 1, and a recording test was conducted. The tlj results are shown in Table 21, and the uniformity of the giant dots was poor. SEM@ inspection of the recording body revealed only protrusions thought to be caused by pigment.

Example 3 Instead of calcium carbonate in Example 1, average particle size 0.03
An electrostatic distribution sheet was prepared in the same manner as in Example 1, except that μ titanium dioxide (225 Japan 7 μ') was used, and a recording test was conducted. The results were good as shown in Table 1.

Example 4 A piece of commercially available synthetic paper (YUBO FPG 90 manufactured by Oji Yuka Synthetic Paper) has an MK conductive resin (C-670 manufactured by Nippon Gosei) whose Xi after drying is 3.0 f/n? A conductive support was obtained by applying the mixture in various manners.

Apply the following dielectric layer paint with paint conditioner for 10 minutes.
Dispersed for minutes, weight after drying is 5, Of/n? An electrostatic recording material was obtained by coating the electroconductive layer on the conductive layer so as to obtain the following.

Styrene resin (Styron 475s made by Asahi Tau 20 titolene solution) IOO part acrylic resin (LR-188 made by Mitsubishi Rayon solid content 4
0%) 112 parts barium sulfate
)r) 35 parts Toluene 86 parts This electrostatic recording material was subjected to the test in the same manner as in Example 1. The results were good as shown in Table 1.

21 ￥ 5 Table Δ Denial defect An electrostatic recorder with no dots and excellent recording uniformity can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of an electrostatic recording medium of the present invention, and FIG. 2 is a schematic cross-sectional view of a conventional electrostatic recording medium. ■・・・Protrusion 2 due to phase separation of resin...Song 2a,
2b Protrusions formed by pigment particles 3... Dielectric layer 4... Conductive TrL layer 5... Supporter Contributor Oji Paper Co., Ltd. Agent Masaaki Kobayashi No. 1 Figure 2 Procedural amendment (spontaneous) July 1920, 70th Indication of the case Showa J1 patent application No. 363 Kota No. 2
Title of the invention Electrostatic recording material 3, relationship to the amended case Patent applicant address V-7-j, Ginza, Chuo-ku, Tokyo Name Tamako Paper Co., Ltd. Representative Nibeku Kawage Agent address No. 7-j, Ginza Hiro-chome, Chuo-ku, Tokyo Target of amendment [Detailed explanation section of specification] Machinery J-kai 1”/Ado
Correct the recording electrode J to be tθ/mm. (2) [...] can be used on the Ota page Ota line of the specification. ”
Next, add the legal text. [In the present invention, the average particle size is indicated by the value calculated according to formula (1) from the specific surface area of the powder measured with a Hondo type specific surface area measuring device, but when the average particle size is approximately o, rμ or less is indicated by the average particle size measured by transmission electron microscopy. (8) Next to "scanning electron microscope" on line 1/page 1 of the specification, write "[(hereinafter referred to as 8PM)" for 6 people. (4) On page 11 of the specification, in the is line “From these results”, the next line is “From the specific surface area measured with the Hondo type specific surface area measuring device, the formula (
Calculated according to 1).

Claims (1)

[Claims] An electrostatic recording material comprising a conductive support and a dielectric layer provided on the conductive support, wherein the dielectric layer has an average particle size of 2 μm or less. ) and at least two types of n-electric 4ii! selected from dielectric resins that dissolve in the same solvent. An electrostatic recording material characterized by being made of fat.