JPS61213853A - Sheet for electrostatic recording - Google Patents

Abstract

PURPOSE:To prevent the curling of base paper for electrostatic recording due to moisture in the open air by adhering a film support to one side of the base paper having low resistance with an electrically conductive adhesive layer. CONSTITUTION:Fine paper is immersed in an aqueous soln. of polyvinylbenzyltrimethylammonium chloride and dried to obtain base paper 3 having low resistance. A coating liq. consisting of polyvinyl butyral resin, styrene resin, silicone resin, finely powdered silica and toluole is applied to one side 4 of the base paper 3 and dried to form a dielectric recording layer 5. A coating liq. contg. an electrically conductive adhesive is applied to the surface of a polyester film 1 contg. a kneaded antistatic agent to form an electrically conductive adhesive layer 2. A sheet for electrostatic recording is obtd. by laminating the adhesive layer 2 on the other side 4 of the base paper 3 having the recording layer 5 on one side 4. The resulting sheet has high suitability to copying and is not curled as the result of a test.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electrostatic recording sheet.

[Conventional technology]

Conventionally, the recording paper used for electrostatic recording is made by impregnating the base paper with a conductive material or by coating both the front and back sides of the base paper with a conductive material, and then applying a recording layer on the conductive layer. Generally, those provided with a dielectric layer are used.

[Problem that the invention seeks to solve]

The conductive layer of the above-mentioned electrostatic recording paper is an important part that affects electrostatic recording properties, and it is necessary that its electrical resistance value is within an appropriate range (surface resistance value of 10 5 to 10 8 Ω/c++!).

For example, if it is less than 105Ω/Cl11, ghosts will occur in the recording layer and image density will decrease;
/aa or more, insufficient charge was injected into the recording layer, resulting in a decrease in image density.

Practical reflection density is required to be about 0.7 to 1.0, and surface resistance value is 105 to 108 Ω/c! For resistance values other than A, there was a defect in that the image density was only about half that obtained.

Furthermore, the surface resistance value of the recording layer itself as a dielectric material is 101
3~1016Ω/cII! As a binder for forming a dielectric recording layer, it is desirable to use a resin that has good charge retention properties that are easy to charge and hard to attenuate. It is desirable to have well-balanced functions such as strength and elasticity depending on temperature and humidity.

Conventionally, typical conductive materials used for the conductive layer include:
There is a product in which 5% polyvinylbenzyltrimethylammonium chloride is dissolved in water, and conductivity is imparted by applying this to the base paper surface and drying it.

Other materials such as sulfonated polystyrene are also used. Then, a coating liquid such as vinyl chloride-vinyl acetate copolymer, silicone resin, etc. is applied to the surface of the base paper which has been made conductive as described above, to form a dielectric layer as a recording layer.

However, conventional recording paper manufactured in this manner has the following defects. For example, −−−−−−−−−
--- ■Since the conductive layer is in direct contact with the atmosphere, it is easily affected by the humidity in the air.

■Due to the large humidity expansion and contraction of the base paper itself, the original dimensions of the recording paper printed by the electrostatic plotter may be incorrect and wrinkles may occur.

(2) When a printer prints a second original from an electrostatically recorded original, there are problems with the transportability and curling of the copy due to the stiffness of the base paper itself.

■Lack of ease of addition, erasability, and strength against tearing with drafting tools such as pencils and ballpoint pens.

(2) If a plastic film is simply laminated, recording by a back electrode type electrostatic block will be insufficient.

There were other defects.

[Means to solve the problem]

As a result of intensive research in order to solve the above-mentioned deficiencies of the prior art, the inventors of the present invention bonded the low-resistance base paper side of electrostatic recording paper to both sides of a film support, which had been given conductivity in advance, via a conductive adhesive layer. The present invention was completed based on the finding that the above-mentioned drawbacks of the prior art can be solved by laminating the sheets into an electrostatic recording sheet.

That is, the present invention is an electrostatic recording sheet characterized in that the low resistance base paper surface 3 of an electrostatic recording paper is laminated on both sides of a film support 1 via a conductive adhesive layer.

The base paper for the electrostatic recording paper used in the present invention is as follows:
The weight of the base paper is preferably 1O to IQOg/rrf
~70g/rrr.

If it is less than 10 g/rd, it becomes porous and it is difficult to obtain a uniform recorded image, which is not preferable.

Moreover, if it exceeds 100 g/nf, the transparency decreases, which is disadvantageous when copying the second original by blueprinting, which is not preferable.

The base paper contains a conductive agent such as polyvinylbenzyltrimethylammonium chloride, a copolymer of 2-acroylethyltrimethylammonium chloride and vinyl sulfone, a sulfonated styrene oligomer, and a quaternized ammonium salt-acrylic copolymer. A low-resistance base paper is obtained by impregnating or coating with a coalesced, quaternized ammonium salt-epoxy copolymer, etc.

The dielectric recording layer provided on the surface of the above-mentioned low resistance base paper is made of acrylic resin, ethylene-vinyl acetate copolymer,
Polyvinyl butyral resin, silicone resin, polystyrene resin, vinyl chloride-vinyl acetate copolymer, vinylidene chloride resin, vinylidene chloride-acrylonitrile copolymer, styrene-acrylic copolymer, cellulose derivative, epoxy derivative resin, etc. in water or organic It is obtained by coating one side of a low-resistance base paper with a coating solution dissolved or dispersed in a solvent.

In addition, extender pigments such as titanium dioxide, zinc oxide, calcium carbonate, barium sulfate, magnesium oxide, and finely powdered silica are added to the above derivative recording layer in order to improve the drying properties and fixing properties of the drawing toner on the surface. You can also use

Examples of the film support to be laminated on the low-resistance base paper surface of the electrostatic recording paper include polyester film, polycarbonate film, acetyl cellulose film,
Polystyrene film, polyethylene film, nylon film, polypropylene film, PVC film,
Anionic, cationic, and nonionic surfactants, special nonionic surfactants, and inorganic salts such as sulfates, phosphates, and sulfonates are applied to films such as vinyl chloride vinyl acetate films and polyimide films. Among these, there is a film that incorporates 0.5 to 30% by weight of additives with low thermal decomposition and good transparency, and its volume resistivity is 105 to 10!5Ω.
It is desirable to have a film in which the physical properties of the film are less likely to change.

In the case of the polyester film used as the film support, 0.5 to 2% by weight of a sulfonate or the like is generally wired.

If the content of the sulfonate or the like is less than 0.5% by weight, the antistatic effect will not be sufficient, and if it is more than 2% by weight, the transparency will decrease (white <) and the physical properties of the film will deteriorate, which is not preferable.

Commercially available films suitable for this purpose include, for example, Lumirror X21, Lumirror

Further, as the film support of the present invention, an antistatic agent may be added on the film, such as polyvinylbenzyltrimethylammonium chloride, sulfonated styrene oligomer, quaternized ammonium salt-acrylic copolymer, quaternized ammonium salt-epoxy copolymer, etc. A material coated with a combination of mercury, etc. is used. Its volume resistance value is 105 to 101
3Ω, preferably 10 7 to 101 OΩcm.

Quaternized ammonium salt on both sides of polyester film
Acrylic copolymer (PQ508 Soken Chemical) 3g/rd
The film support provided has a volume resistivity of 1010 Ωcm and can be used as the film support of the present invention.

Furthermore, as another film support, a metal oxide such as In203/SnO2, ZrO2, Cd25n04, or CL11% Pb5Cu-, AI
, sputtering film of metal such as Cr etc. 20~5000
Those provided by the person are used.

If the sputtering film is less than 20 Å, no antistatic effect can be obtained, and if it is more than 5,000 Å, it becomes opaque and prone to cracking, which is not preferable.

Conductive material is deposited or sputtered on the antistatic agent-mixed film or film support so that the film has a transmittance of 40% or more (600n+μ) and a volume resistivity of 10' to 1010Ω. Can be used as a sexual support.

In203 /Sn02 50 people 106Ω/cd
85%Cr 100 people 107Ω/c+J
For example, as a commercially available product, the product name: SEREFUKU (manufactured by Seelasin Co., Ltd.) with a volume resistivity of 109 Ω is used.

Examples of the conductive adhesive used in the present invention include polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, acrylolitrile rubber, urethane rubber, polyester resin, alkyd resin, Antistatic agents, such as low Preferably 0.5 to 30% by weight of molecular weight polystyrene sulfonate, quaternized ammonium salt-acrylic copolymer, quaternized ammonium salt-epoxy copolymer, steramidopropyl dimethyl-β-hydroxyethylammonium nitrate, etc. is blended in an amount of 1 to 5% by weight, and its surface resistance value is adjusted to be 106 to 107 Ω/-.

In addition, In2O3/Sn02 is added to the synthetic resin or rubber.
A conductive adhesive coating solution obtained by dispersing powder and doping with antimony oxide to change the conductivity is coated and dried to achieve a surface resistance value of 106~
It is also possible to obtain a conductive adhesive layer of 107 Ω/-.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 40 g/rrl of high-quality paper was added to a 5% aqueous solution of polyvinylbenzyltrimethylammonium chloride and dried to obtain a low-resistance base paper.

Next, the following coating solution was applied to one side of the low-resistance base paper using a Meyer bar #30 and dried to obtain a dielectric recording layer having a thickness of 6 μm.

Polyvinyl butyral resin 8% by weight styrene resin 2% by weight silicone resin
1% by weight fine powder silica
4% by weight Dorol
85% by weight - A conductive adhesive coating solution having the following composition was applied to a 100μ thick surface of a polyester film kneaded with an antistatic agent (product name: Lumirror A drug layer was obtained.

Polyester resin 20% by weight (product name: Byron 300 Toyobo product) Antistatic agent
4% by weight (product name: Chemistat) 2
009A Sanyo Chemical Co., Ltd. product) Methyl ethyl ketone
46% by weight Dorol
An electrostatic recording sheet was obtained by laminating a conductive adhesive layer on the other side of the low-resistance base paper on which a 30% by weight dielectric recording layer had been previously formed.

The results are shown in Table-1.

Example 2 15 g/rd of base paper was impregnated into a 5% alcohol solution of quaternized ammonium salt-acrylic copolymer and dried to obtain a low-resistance base paper.

Next, a coating solution having the following composition was dispersed for 48 hours on one side of the low-resistance base paper using a ball mill and dried using a #20 Meyer bar to obtain a dielectric recording layer having a thickness of 7 μm.

Polyester resin 10% by weight (Product name: Byron 200 Toyobo product) Vinylidene chloride-acrylonitrile resin 10% by weight (Product name: Saran R202 Asahi Kasei product) Polyvinyl butyral resin 1% by weight Calcium carbonate
1% by weight fine powder silica
3% by weight methyl ethyl ketone 4
0% by weight Drol 25% by weight Cyclohexanone 10% by weight Meanwhile, the following conductive adhesive was applied to the surface of a separately prepared sanded polyester film (trade name: Lumirror A conductive adhesive layer having a thickness of 10 μm was obtained by applying the liquid.

Next, this was laminated in the same manner as in Example-1 to obtain an electrostatic recording sheet.

The results are shown in Table-1.

Polyester resin 15% by weight (Product name: Byron 300 Toyobo product) Acrylonitrile rubber 3% by weight (Product name: Hiker 1432
J Japan Synthetic Rubber Co., Ltd. product) Ethylene-vinyl acetate copolymer
2% by weight Catanac (antistatic agent) 10% by weight Methyl ethyl ketone 40% by weight Drol 30% by weight Example-3 Antistatic agent kneaded polyester film (trade name: Lumirror A low-resistance film support was prepared by adhering 20 μm of metallic chromium, and a conductive adhesive similar to that in Example 2 was applied thereto to obtain a conductive adhesive layer with a thickness of 10 μm.

Next, the low-resistance base paper surface of the electrostatic recording paper prepared in the same manner as in Example 2 was laminated with the above conductive adhesive layer to obtain an electrostatic recording sheet.

The results are shown in Table-1.

[Effect]

In the electrostatic recording sheet obtained in the present invention, the low-resistance base paper surface is adhered to the film support and the conductive adhesive layer, so the low-resistance base paper surface is not in direct contact with the atmosphere.

As a result, there is no fear that the electrostatic recording base paper will curl due to the humidity of the outside air.

It also has the effect of reducing damage and humidity expansion/contraction.

Since a conductive support is used as the film support, the impedance of the low resistance layer can be lowered, thereby increasing the recording speed.

Furthermore, since the conductive support (antistatic agent-mixed film) is electrically conductive, good images can be obtained with any model that requires a back electrode or a model that has electrodes on the same surface.

The image quality is stable because there is almost no charge fluctuation during supersaturated charge when charge is injected into the dielectric recording layer at -600 to -900V charge.

This electrostatic recording sheet has many advantages such as improved copyability when duplicating a second original, ease of addition with a pencil, ballpoint pen, etc., and excellent dimensional stability.

[Brief explanation of drawings]

1 to 4 are cross-sectional views showing an example of an electrostatic recording sheet according to the present invention. - Film support 2 - Conductive adhesive layer 3 - Low resistance base paper 4 - Low resistance base paper surface 5 - Dielectric layer 6 --- Antistatic agent kneaded film 7 --- Sanding mat surface 8 --- Metal, metal oxide sputtering film Figure 1

Claims (8)

[Claims] (1) An electrostatic recording sheet characterized by laminating a low-resistance base paper surface 3 of an electrostatic recording paper on one or both sides of a film support 1 via a conductive adhesive layer 2. (2) The film support has a volume resistivity of 10^5 to 10^1
The electrostatic recording sheet according to claim (1), which is a film in which an antistatic agent of ^5 Ωcm is kneaded. (3) The film support has a volume resistivity of 10^5 to 10^1
The electrostatic recording sheet according to claim (1), which is an antistatic agent-mixed film having a resistance of 5 Ωcm, and one or both sides of the antistatic agent-mixed film are sanded. (4) The film support is coated with a dispersion containing a metal or metal oxide on one or both sides, and has a volume resistivity of 10^5 to 10^1^5 Ωcm. The electrostatic recording sheet described in item (1). (5) The film support has a sputtering film of metal or metal oxide on one or both sides of the film support,
Å, and its volume resistivity is 10^5~10
The electrostatic recording sheet according to claim (1), which has a resistance of ^1^5 Ωcm. (6) The film support is coated with an antistatic agent or antistatic resin on one or both sides, and
The electrostatic recording sheet according to claim (1), which has a volume resistivity of 10^5 to 10^1^5 Ωcm. (7) The surface resistance value of the conductive adhesive layer is 10^5 to 10
The electrostatic recording sheet according to claim (1), which has a resistance of ^8Ω/cm^2. (8) The conductive adhesive binds metal or metal oxide to 20%
-300% by weight, preferably 40-80% by weight,
Moreover, its surface resistance value is 10^5 to 10^8 Ω/cm^
2. The electrostatic recording sheet according to claim (1).