JPS5868044A - Electrostatic recording material - Google Patents

Abstract

PURPOSE:To improve developing efficiency and to obtain a recording material high in image density and long in durability, by forming a dielectric layer on a conductive substrate to provide an electrostatic recording material, and preparing the dielectric layer by dispersing surface-roughening particles into a binder resin and controlling dielectric constant to a value not exceeding a specified value. CONSTITUTION:Aluminum or the like conductive base 3 is formed on a support 4 of a polyester sheet or the like, and a dielectric layer 2 obtained by dispersing surface-roughening particles, e.g. ZrO2, TiO2, Al2O3, or the like, into a binder resin, e.g. modified polyurethane resin, or the like is formed on the base 3. This layer 2 has <=9, preferably 3-6 dielectric constant, and >=10ohm.cm volume resistivity. An electrostatic latent image is formed on the layer 2 of the recording material 6 (a belt in the figure) using a stylus or a recording needle 1, developed with a magnetic roller 7, the obtained toner image is transferred to a transfer paper 10 to obtain a recorded image 11. The recording material 6 is cleaned 12, destaticized 13, and repeatedly used, thus permitting a high density image similar to the initial image to be obtained after long-term use.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electrostatic recording material in which a dielectric layer is provided on a conductive substrate.

In recent years, with the increase in the amount of information, and social demands such as resource saving, labor saving, and non-pollution, various recording methods have been put into practical use and improved in the information recording field, among which electrostatic recording methods. I) The image signal forming means is inexpensive and simple.

(2) Plain paper can be used for recording paper, reducing recording paper costs.

(2) It has a latent image recording section or a solid-state electronic set, which has excellent resolution, and the printing speed is extremely fast at more than 10 μsee/dot.

Next, in order to record an image using the electrostatic recording method, for example, 1
) irradiating an ion stream imagewise onto the electrostatic recording medium or scanning with a stylus (recording needle); 2) transferring the electrostatic latent image once formed on the electrophotographic photoreceptor onto the electrostatic recording medium; After transferring the ItF image onto the surface of the image, it is visualized by developing it with an electroscopic developer.

These image recording methods (particularly 1 above) can be seen from a different perspective, with each type having a scanning type with a movable part, a fixed type Q) recording head with multiple needles, an air gap discharge type, a rear control type, etc. It is connected to the possibility of being hired.

In addition, in the past, the a image formed on the dielectric recording layer by the above-mentioned recording method θ) is developed with an electroscopic developer (electroscopic toner), and 0) the toner image is fixed as is. Recently, it has become possible to transfer the electrodetectable toner image to other transfer materials (e.g., paper, cloth, synthetic paper, etc.) and fix it, so that the electrostatic recording material can be used repeatedly. A recording method using a transfer method, that is, a transfer electrostatic recording method, has come to be adopted, and the recording medium according to the present invention is
The method used is also 0).

The static RL latent image is formed by causing a discharge between the stylus and the dielectric layer of the recording medium, and for this purpose a voltage higher than the discharge starting voltage curve must be applied to the stylus. If the gap between the stylus and the dielectric layer is too small, the voltage required to start a discharge will rise rapidly, making it difficult to discharge. 16. Conversely, if the gap is too large, the voltage required to start the discharge will increase, making it difficult to emit ffW and L, and the resolution will deteriorate. It is highly dependent on the stylus and the gap distance in g*,
Accurately managing this gap spacing on the order of pm is
It was extremely difficult.

Conventional transfer mold 111. In the recording medium, a dielectric layer with a smooth surface θ) was used to mechanically manage the gap spacing, but the gap spacing maintenance machine was lJ! ', low value, low reliability,
Although it was satisfactory, it was not θ〕. Therefore, by forming unevenness on the surface of the recording medium and bringing the recording electrode into contact with this, a gap between the recording medium and the recording medium is secured under the recording electrode where discharge is most likely to occur due to the unevenness of the surface of the recording medium. death,
Although this work has been carried out mainly on electrostatic recording media to form a military image, the main focus was on improving the dusting characteristics θ of pencils and the like.

Although there are various factors that influence the recording characteristics, there are many factors that influence the recording characteristics, but the
) The correlation between the attraction rate and the recording (latent image) potential, which is one of the special characteristics, is known.

Therefore, the inventor of the present invention focused on the fact that the recording potential is largely dependent on the dielectric constant of the dielectric layer 0), and conducted experiments to find out that the recording potential is highly dependent on the dielectric constant of the dielectric layer θ) which provides excellent recording properties. The present invention was achieved by discovering the dielectric constant.

That is, the electrostatic recording material for transfer type (θ) of the present invention has a dielectric constant value of 9 or less, preferably 3 to 3, of visiting pigeons dispersed in fecal matter containing surface roughness forming particles 8 on a conductive substrate. 6.

The dielectric layer of the n-type recording material for transfer type has a high dielectric constant, that is, 9
If this is the case, the TRP capacitance becomes large and the recording potential becomes low. This greatly affects the development efficiency by electric field in toner development, leading to a decrease in image density.

Next, from the value of the dielectric constant of the present invention, di'r1. Layer θ] The effective thickness of the dielectric 11°C layer, expressed as the ratio of film thickness and dielectric constant, is 2μ
m to 10 μm is desirable.

In addition to the dielectric constant, a factor that affects the recording potential is the volume electrical resistance of the dielectric layer, which has a large effect on the recording, mountain, and bamboo Q), and when the resistance is low, the retention of the recording potential θ) decreases. Because of this, the first place in the record is reduced before entering the next process, and the reliability of the process decreases. Experimentally shown in Figure 1 Q)
The following relationship is established, and it can be seen from this that if the dielectric layer has a resistance value of 1010 Ωm or more, the deterioration of the recording potential can be suppressed.

Also, the silent recording medium of the present invention can be used in a transfer type electrostatic recording system. Because it is exposed to a lot of damage, it is prone to scratches and scratches. Therefore, in order to improve the durability of the recording medium, it is necessary to increase the hardness of the surface of the recording medium. Experimentally, the surface hardness was determined to be JIS K-541'l O,
A pencil scratch test revealed that 3H or more was required.

The electrostatic recording material for transfer type (θ) of the present invention has the above-mentioned conditions, but in order to actually create the recording material, as shown in FIG. 6 with 3
A dielectric layer forming liquid containing surface unevenness forming particles (zirconia oxide, titanium oxide, aluminum oxide, hard ceramic material, etc.) in a binder resin (modified urethane resin, modified silicone resin, etc.) is applied onto the self-recording support 4. Raw cloth, just dry it.

Next, in order to actually obtain a recording method using the present invention θ) static...; For example, the process shown in Fig. 3 θ) is sufficient. An endless belt of soap′
-L by multi-stylus (multi-needle electrode) 1 on recording body 6
I! A multiplied pressure in the I11 area is applied to form an electrostatic latent image. O) Image the latent image 4j with a developing mag roller 7 to obtain a toner image 8,
The image is then transferred onto plain paper 10 as a transfer paper by a transfer corona charger 9 to obtain a recorded image 11. Even after the transfer process, the toner adhering to the recording medium 6-1 is removed by a cleaning roller 121, and then statically removed by a static eliminating corona charger 13, and the electrostatic recording medium 6 is used again.

Note that the shape of the electrostatic recording body 0) is not limited to any particular shape, but from the viewpoint of repeated use, an endless belt shape, a rigid drum shape, etc. are generally used.

Next, examples will be shown.

Example 1 In accordance with the present invention, a recording medium was prepared in 8i1.
A sample for dielectric constant measurement of the recording material of the present invention was prepared. For this purpose, zirconia oxide fine powder (4,87'Jδ=35pm)1
Double lid: 10 parts by weight of methyl ethyl ketone The above composition was dispersed in a ball mill for 1 hour, and then 1 was added as incyanate and thoroughly stirred to prepare a g-electrolayer forming liquid. This dielectric layer forming liquid was applied onto an aluminum plate with a thickness of 1 mm using a blade coating method, dried at 90°C for 30 minutes to form a dielectric layer with a thickness of 30 μm, and then coated on top of the dielectric layer using a vacuum steaming method. An aluminum electrode was made and a sandwich-type sample for dielectric constant measurement was obtained. Please send this sample to YHP
The capacitance was measured using a 4261A LCR meter manufactured by the company, and the dielectric constant was calculated from this single peak and found to be 4.3.

Example 1+112 Same conditions as Example 1, except that a binder resin with a different dielectric constant was used to clarify the relationship between record -7th place and the visitation rate of the turtle layer. The dielectric constant was determined. Next, 15μ of Example 1 and others θ)4′[lc tm forming solution was added.
Example 1
It was coated and dried in the same manner as described above to prepare a recording medium having a 1q layer of 15 μm O). Then, in the process shown in Figure 3, the stylus applied voltage -35+IV and the segment pressure +
A latent image was written at 350V, and Kawaguchi's 1F (Answer 1)
When the recorded potential was measured using a type acid level meter, the relationship shown in Figure 4 (Q) was obtained. Especially implementation? Dielectric constant of 111 (#=4.3
) of the recording medium of the present invention (Jif is 15 (I
V.

The effective film thickness was 3.5 Pm, and the dielectric layer Q) volume resistance was 3.8×10 14 Ω. From the results shown in Figure 2114, it was found that a high recording potential can be obtained when the dielectric constant is 9 or less, preferably 3 to 6 Q).

Example 3 The present invention's NL record 9 in which the dielectric layer's μ ratio is 4.3
The surface hardness of the whole was determined. Surface hardness is JISK-540
0, 5H in pencil scratch test.

Furthermore, in order to clarify the durability of the recording medium, a large number of latent images were continuously written on plain paper under the same conditions as in Example 2.
Recording potential and image density were measured at any time. The result is 5th.
It is shown in Figure 6. (However, the density was measured using the Macbeth density side.) From the results shown in Figure 5.6, plain paper 2
There was almost no difference in the recording potential after 10,000 copies and the degree of 11 degrees of song recording compared to that at the initial stage, indicating that the recording medium of the present invention has extremely excellent durability.

[Brief explanation of the drawing]

Figure 1 is a graph showing changes in electric potential with respect to reduction time, with the dielectric layer 0) volume resistance 1th set to 6 ramets.
curve). FIG. 2 is a schematic diagram of the silent recording medium (recording section Q to which this is applied). FIG. 3 is a schematic diagram of the process applied to the transparent recording medium. Figure 4 is a graph showing the relationship between the dielectric layer's Vi visit rate and the record -1st position.
It is. FIG. 5-10 is a graph (curve) showing changes in recording position and number of sheets of plain paper. FIG. 6 is a graph (curve) showing the change in image protection θ) of ten plain papers with respect to the number of sheets of plain paper. 1... Stylus 2... Temperature '1□ff, /
li3...4*, layer 4...Recording body support 5...Elastic rubber roller 6...Recording body 7...Developing mag roller 9...Transfer Kol Kona charger 10...Chopsticks Paper passing 12...Cleaning roller 13...Deweighting corona charger 14...Toner reservoir 15...Roller 11- Purse 10 Child 2 and 3 Figures

Claims (1)

[Claims] L In an electrostatic recording material for light copying, in which a dielectric layer in which surface unevenness forming particles are dispersed in a binder resin is provided on a conductive substrate, the dielectric constant value of the dielectric layer is 9 or less. Characteristic electrostatic recording material.