JPS60128450A - Electrostatic recording member - Google Patents

Abstract

PURPOSE:To enhance weather resistance, electrical and mechanical durability, etc., by forming successively on a support a conductive layer, and a recording layer obtained by applying a coating material contg. a solvent-soluble type reactive fluororesin and a cross-linking agent. CONSTITUTION:A conductive layer obtained by dispersing a fine conductive powder into an org. polymer binder, or a conductive layer made of a metal vapor deposition film is formed on a support made of polyester or the like. A recording layer is formed by coating said conductive layer with a mixture of a solvent- soluble type reactive fluororesin and a cross-linking agent, such as polyisocyanate, to prepare an electrostatic recording member. As said polymer binder, polyester, acrylic type resins are usable, and as the conductive powder, carbon black, etc. are usable, and the metal vapor deposition conductive layer can be formed with Pd-Pt, Sn-Sb oxide, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic recording medium used in a toner image transfer type electrostatic recording method, and particularly to an electrostatic recording medium that can be used repeatedly.

The electrostatic recording medium of the present invention basically has a three-layer structure consisting of a support, a conductive layer, and a recording layer.

The present inventors have previously developed an electrostatic recording material k'l''I.
7 1 1: S zl il &ko・proposal/c-n
As shown here, when a polyester film is thermally laminated as a means for forming a recording layer on a conductive layer, there is little adverse effect on the conductive layer. However, when a resin solution is applied as the recording layer, there is a problem that the coating liquid permeates into the conductive layer and the surface resistivity value of the conductive layer fluctuates greatly.

The present invention solves these problems. That is, the object of the present invention is to form a recording layer by coating without changing the surface resistivity value, to make the recording layer stable against environmental conditions, and to have four characteristics, mechanical and electrical properties. The object of the present invention is to obtain a recording layer for an electrostatic recording medium which is excellent in surface and one-time durability and which is easy to clean.

For this reason, we have investigated various resin solutions to ensure that they meet the performance requirements as a recording layer, and that when coated on a conductive layer, the fluctuation range of the surface resistivity value is relatively small, resulting in a stable and high product yield. We have discovered a solvent-soluble reactive fluororesin as a material for the recording layer that can be manufactured in this manner.

That is, the present invention provides a conductive layer composed of a system in which conductive fine powder is dispersed in an organic polymer binder or a conductive layer composed of a metal vapor-deposited film, in which polyisocyanate-1 is added to a solvent-soluble reactive heptad-based resin. This invention relates to an electrostatic recording medium characterized by having a recording layer formed by applying a compounded liquid containing a crosslinking agent such as .

Examples of the organic polymer binder include polyester, acrylic, urethane, rubber, epoxy, and melamine resins, and examples of conductive fine powder include carbon black and graphite. be able to.

Further, examples of the conductive layer formed by metal vapor deposition or sputtering include palladium-platinum, tin-antimony oxide, etc., but are not limited to these.

The surface specific resistance value of the conductive layer of the electrostatic recording material of the present invention is
) A range of 6 to 108 Ω/mouth is preferable, and images are clearly expressed.

Surface specific resistance value is less than 10607 or 108Ω
/ Beyond the mouth, the image density becomes thinner and the image becomes thicker, which is not desirable.

Conventionally, the fluororesin used for the recording layer is insoluble in solvents, and it has been impossible to create the recording layer by coating. However, the reactive fluororesin used in the present invention is soluble in solvents, can be easily coated, and has good adhesion to objects to be coated. Furthermore, by adding a crosslinking agent such as polyisocyanate, the strength of the resin film was significantly improved, the abrasion resistance was excellent, and the adhesion to the coated object was also improved.

As the reactive fluorine resin, Asahi Glass (manufactured by Lumif o y
LF 100, Lp-200,i, tr-30Or
, 1. As a crosslinking agent, polyisocyanates manufactured by Nippon Polyurethane, such as Coronate I-■, can be used.
, Coronate I-1, L, Coronate E I-1, etc., but are not limited thereto.

The recording layer of the electrostatic recording material of the present invention may be a dielectric material itself or glass formed by applying a compounded solution of a solvent-soluble reactive fluororesin with, for example, polyisocyanate added as a crosslinking agent. ,S+02,
Al2O'3, Ti (Jz, Z n 0, etc.) Free rFJ
It may also be a mixture with dielectric material powder.

The thickness of the recording layer should be at least 1 mm to avoid dielectric breakdown.
From the viewpoint of resolution, it is preferably 20μ or less.

As a method for coating the recording layer, conventional coating methods such as brush coating, dip coating, air knife coating, roll coating, spray coating, and fountain coating can be used.

The electrostatic recording material of the present invention is an electrostatic recording material used in a method of transferring onto plain paper, and has excellent mechanical and electrical durability.
Note that even after repeated use, electrical deterioration does not occur, and high-quality images can always be obtained. Incidentally, we conducted a recording test 30,000 times and no deterioration in performance was observed. The electrostatic recording method using the electrostatic recording medium according to the present invention can be widely used in facsimiles, various printers, etc. because the recording speed is sufficiently high, the obtained image quality is good, and the device is easy to maintain.

The present invention will be explained below with reference to Examples.

In addition, all "parts" in each example are 1 part by weight, and the surface resistivity value was measured by the following method.

That is, the obtained electrostatic recording material is 7 l in length and 1 ocrn in width.
Cut it into a quadrilateral, remove the recording layer to a width of 1.5 cm on both sides, apply grounding material, and dry. Then, the measuring portion of the recording medium is made to form a square of 7C/n sides. The grounding material used is one in which the ratio of carbon black added to the binder is increased and the resistance value inherent to the surface of the dried coating film is adjusted to approximately 102 ohms. Sandwich the ground portions at both ends with metal clips, and then connect the
10-350) and apply a constant voltage of 25V to both ends. The current that flows between these after 1 minute (1) is all one. knee and
Read with a digital multimeter manufactured by Dee Co., Ltd., and calculate the surface specific resistance value R (Ω) using the following formula.

Example 1 100 parts of polyurethane resin (elastomer made from the reaction of polyester and polyincyanate; Rezamin co-520LV manufactured by Dainichiseika Chemical Industry Co., Ltd. + solid content 30.0%) and 45 parts of carbon black (Inunichisei Chemical Co., Ltd.) predispersed Kakogyo Seiryoku Cebu 707-960゜solid content 30%) and 1
44.2 parts of methyl ethyl ketone and 1.4 parts of Coronate 1 [condensate of trimethylolpropane/tolylene diisocyanate (l/3 molar ratio) manufactured by Nippon Polylanthane] were mixed and coated by stirring for 10 minutes. The liquid was adjusted [solid content 15 parts, (carbon black/binder resin) ratio -020].

The two-component coating is applied to the corona discharge treated surface of a 75 μ thick biaxially stretched polyester film (manufactured by Diafoil) using an applicator so that the dry coating thickness is approximately 20 μ, and dried to form a conductive layer. shall be. The surface specific resistance value of this conductive layer was j-X 107Ω/mouth. Next, a solvent-soluble reactive fluororesin (Lumiflon, LP-100:
Asahi Glass Co., Ltd.) 100 parts and 7,200 parts of methyl ethyl keto and poly, isonoane-1 (Coronate 1) as a film agent.
y I-1: Mix 10 parts of Nippon Polyurethane Co., Ltd. and stir for 15 minutes to prepare a coating solution.

This solvent-soluble reactive fluororesin compound GL was applied onto the conductive layer by a dipping method, dried at 110°C for 30 minutes, and cured (
-A recording layer was formed. At this time, masking tape is attached to both ends of the recording body to prevent the recording layer from being coated. A low resistance electrode material (1O
2Ω/hole) and measured the surface resistivity value of the conductive layer, the surface resistivity before and after coating the recording layer and the range of value fluctuation were determined. This is shown in Table-1.

Using this recording material, a signal was applied with a multi-stylus, and after development, the image was transferred and fixed onto plain paper, and a clear image with no image thickness was obtained.

Example 2 Solvent-soluble reactive fluororesin (Lumiflon L"-2
00; manufactured by Asahi Glass ■) 100 parts and 50 parts of methyl ethyl ketone
Polyisocyanate (Corone-1-
g f-1: 10 parts of Nippon Polyurethane Kikki Co., Ltd.) were mixed;
The coating solution was prepared by stirring for 5 minutes.

A recording medium was manufactured using this coating liquid in the same manner as in Example 1, and the surface resistivity value after coating the recording layer was measured (shown in Table 1), and the fluctuation range was small.

Using this recording medium, a signal voltage was applied with a multi-stylus, and when the image was transferred and fixed onto plain paper, a clear image with no thickening was obtained.

Example 3 Tin oxide-based sputtering film (Seresoku-B
07Ω/mouth) using a recording layer coating liquid prepared in the same manner as in Example 1, coated, and dried.

It was cured to form a recording layer. The surface resistivity value after coating the recording layer was measured (shown in Table 1), and the fluctuation range was small.

Using this recording medium, a signal voltage was applied with a multi-stylus, and when the image was transferred and fixed onto plain paper, a clear image with no thickening was obtained.9 [Comparative Example ■] Acrylic light 100 parts of reactive resin (81%-6001; manufactured by Daicel Chemical Industry ■), 170 parts of dipentaerythritol hexaacrylate (Nippon Kayaku ■1), 100 parts of a photopolymerization initiator (manufactured by Irgacure SMark), and 1 part of Ky7lene.
00 parts and 370 parts of n-butanol and stirred for 15 minutes to prepare a coating solution.

This coating solution was applied by dipping onto a conductive layer prepared in the same manner as in Example 1, dried at 130°C for 2 minutes, and exposed to ultraviolet light (30CTL using a 2KW ultra-high pressure mercury lamp). The recording layer was photocured by irradiation for 30 seconds at a distance of .

The range of variation in surface resistivity of the conductive layer before and after coating the recording layer was determined in the same manner as in Example J. This is shown in Table IK. , compared with Example 1 and Example 2, the variation range of the surface specific resistance value was wide.

Claims (1)

[Claims] In an electrostatic recording medium in which a conductive layer and a recording layer are sequentially provided on a support, the recording layer is composed of a solvent-soluble reactive fluororesin and a crosslinking agent. An electrostatic recording material characterized by being coated with ff1k.