JPS5937551A - Electrophotographic transfer sheet - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic transfer sheet capable of obtaining a sharp electrophotographic image, by using said sheet having a metal or its compd. layer detectable by a proximity detector, and having a specified electric resistance value. CONSTITUTION:A paper or plastic film layer 2a, 2c is formed on both sides of a thin film layer 2b made of metal or metal compd. (e.g., aluminum) detectable by the approaching detector, and it has >=5.0X10<9> ohm surface electric resistance value and/or >=1.0X10<10> ohm.cm vol. resistance value in the environmental conditions of 20 deg.C temp. and 65% humidity. As a result, a sharp electrophotographic transfer sheet is obtained. When it is used as an original for a copying machine provided with the proximity detector, it is possible that a signal is produced by discriminating said sheet from an ordinary sheet, and the functions of the copying machine can be controlled automatically by stopping copying, rendering its copy unreadable, separating it into another sorter, or changing the color of a developing toner at the time of copying.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic transfer sheet containing a metal or metal compound that can be detected by a near-d switch.

With the spread of office copy machines and facsimile machines.

It would be highly desirable to provide a practical means to prevent unauthorized copying of confidential documents or copyrighted records, and several methods have already been proposed. The present inventors also process the document sheet by metal vapor deposition, coating, impregnation, bonding, etc., and also detect and respond to the metal in the document sheet in accordance with the scanning exposure process of the document being copied. We are proposing a GC location with a means.

The purpose of this invention is to provide an electrophotographic transfer sheet that can be used to prevent the copying of information once copied in the confidential document copying apparatus proposed by the present inventors. be.

2. Description of the Related Art Conventionally, metal-containing sheets include, for example, aluminum vapor-deposited paper for discharge recording. As shown in the cross-sectional view in FIG. 1, this is made by providing a carbon layer 1h, an aluminum vapor deposited layer 1C, and a white conductive layer 1d on a base paper 1a. Even if such a metal-containing sheet is passed through an electrophotographic copying machine to obtain a copy, the electric charge will escape due to its low electrical resistance, so it cannot be transferred, so it can be used as an electrophotographic transfer sheet. did not previously exist.

This invention has an electrical resistance value of 20C that can be detected by a proximity detector and can also be used as an electrophotographic transfer sheet.
1 Humidity (R, H,) The surface resistance value under the condition of 65- is 5.0 x 109Ω or more, and/or the volume resistance value is 1.
This is the first time that we have provided a transfer sheet with a resistance of 0x10" Ωcm or more.

The structure of the electrophotographic transfer sheet according to the present invention is as shown in FIG. 2. For example, as shown in FIG. For the first step in obtaining the resistance value, you can choose the type of adhesive you want, depending on your needs. Examples of the eyebrow agent include acrylic resin emulsion, +F polyethylene at Jltt emulsion, synthetic rubber latex, and acrylic ester copolymer. Further, the thickness of the entire thin film layer is not particularly limited, and it is preferable that the thickness < rc (60 μm or less) from the viewpoint of paper passing through a copying machine such as Xerox. Further, the thickness of the paper or plastic layer is preferably more than 10 μm, and there is no particular upper limit.

FIG. 6 shows another example of the structure of the electrophotographic transfer sheet of the present invention.
Although an electrical resistance adjustment layer 6 is provided on the gold part-containing layer 3b of A oxide or the like, the one shown in FIG. 2 is preferable from the viewpoint of runnability in a copying machine.

Examples of metals or metals in metal compounds that can be detected by the proximity detector that can be used in the present invention include aluminum, iron, copper, zinc, cadmium, silver, and nickel, but aluminum is most preferred from the viewpoint of manufacturing. .

Lol! In the case of the configuration shown in Figure 1, the electrical resistance adjustment layer contains acrylic resin, epoxy resin, vinyl acetate resin, styrene-butadiene copolymer ac\lyl branched ester copolymer, etc. as the main component, and optionally An electrical resistance adjuster is added to adjust the surface resistance value to 5×10 9 Ω or more, or the volume resistance value to i x io”0 or more.

Proximity detectors can detect all metals in a non-contact state by utilizing changes in the impedance of the oscillation coil of a high-frequency oscillation circuit caused by eddy current loss, and the internal structure is well known, so details will be omitted. .

Next, the electrophotographic transfer sheet of the present invention will be explained with reference to Examples and Comparative Examples.

Example 1 An acrylic resin adhesive was applied to one side of 45 kg of commercially available high-quality paper, and a 10μ thick γ-luminium thin film was pasted on top of it. [7. Paper 9 was pasted on high-quality paper 45 to obtain metal-containing paper.

Example 2 Commercially available high quality paper 45kl? Spread cellulose adhesive on one side of the paper, paste a thin aluminum film with a vcH of 15μ on top of it, and apply polyethyl acrylate emulsion 5 on top of it.
0 parts by weight of mackerel (as solid content), 40 parts by weight of calcium carbonate, 10 parts by weight of Punpun, 50 parts by weight of water! A metal-containing paper was obtained by applying 8P/1-1 coat of paint consisting of If amount part as a dry coating.

Comparative Example 1 3 kg of copper iodide wet cake, 400 t of 20 ml water bath liquid of styrene maleic acid copolymer, SBR latex 2
00y and 2CN6 water bath solution 1009 of ammonium carbonate were mixed and dispersed and mixed for 1 hour using a pulverizer kC using a glass bead with a diameter of 5 fins to obtain a coating solution. Apply this coating liquid to 45 ml of high-quality paper.
A comparative sheet was obtained by coating one side of paper so that the dry coating gave It 10 P/-.

Example 6 On the coated surface of the sheet prepared in Comparative Example 1, a paint consisting of 50 parts by weight of tC styrene tadiene latex (as solid content) and 50 parts by weight of calcium carbonate was applied during drying If
10? /21'' to obtain a sheet.

Comparative example 2 45kg high quality X8 single-sided VC polyvinyl alcohol (P
VA) A comparative sheet was obtained by applying water M paper and pasting a 20 μm aluminum thin film thereon.

Table 1 shows test data on the copy quality of the electrophotographic copying machine and the runnability of the copying machine for the sheets obtained in Examples 1 to 3 and Comparative Examples 1 to 2.

Table 1 0: Good, △: IIJ-Possible: Use: Unusable*
The electrical resistance of a sheet that has been conditioned for 4 hours or more under the environmental conditions of 20U and 65% humidity is JISC-2122-
17: LfiK specified and using b'&m (applied voltage', 100 V PC=t: Measured.

※※ The resistance was too low and the needle of the measuring device wavered off, making it impossible to measure.

From the results in Table 1, it is clear that the sheet σ) of the present invention has excellent properties.

As described above, the present invention provides an electrophotographic transfer sheet that contains a metal or a metal compound that can be detected by a proximity detector and is capable of obtaining a clear RL electrophotographic transfer image. When used as an original in a copy machine equipped with It is also possible to automatically control the functions of the copying machine by changing the color of the temporary developing toner.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a discharge recording paper, and FIGS. 2 and 6 are sectional views of examples of an electrophotographic transfer sheet of the present invention. Symbols in the figure: 1a... Base paper; 1b... Carbon layer; 1C... Aluminum vapor deposited layer; 1d... White conductive layer 12a+2c...
Paper or plastic film; 2b... thin film layer throughout the area;
3a... paper or plastic film; 5b... metal-containing layer; 6C... electrical resistance adjustment layer.

Claims (1)

[Claims] It has a metal or metal compound layer that can be detected by a proximity detector, and has a surface electrical resistance value of 5.0 under environmental conditions of temperature 20C and humidity 65C. 1. A transfer sheet for electrophotography, characterized in that OX is 109 Ω or more and/or a volume electric resistance is i, ox io 10 Ωcm or more.