Compositions – Electrically conductive or emissive compositions
Patent
1989-01-04
1991-03-05
Welsh, J. David
Compositions
Electrically conductive or emissive compositions
2525011, 338 14, 338 15, 430 58, H01B 100, H01C 1300
Patent
active
049975935
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a material having a variable electroconductivity and more particularly to a material the electroconductivity of which can be reversibly or irreversibly varied by application of light or heat energy thereto and also to a method for utilizing the same.
BACKGROUND ART
As one of the methods for making certain information contained in a memory medium obtainable, there is known the method of utilizing memorizable electroconductivity variation. According to this method, by effecting exposure corresponding to recording information on a specific photosensitive material, electroconductivity variation having memorizability is created at the exposed portion, and the recorded information can be visualized by, for example, various developing methods employed for electrostatic photography. Also, such photosensitive material which brings about memorizable electroconductivity variation by light may be considered for uses as an optical forming memorizable electroconductive circuit or an optical switching device, since the current flowing through the photosensitive material varies under the voltage applied state.
In the prior art, various memorizable photosensitive materials have been proposed for electrostatic photography (for example, U.S. Pat. No. 3,879,201 and 3,997,342).
However, in the memorizable photosensitive materials of the prior art, for obtaining a desired image, there are problems such as that the exposure dosage must be made relatively larger (10 mJ/cm.sup.2 to 100 mJ/cm.sup.2), and also that the time in which the memory effect is stably maintained is short (some 10 minutes to about 1 hour).
In view of the problems of the prior art, I have proposed various improvement techniques for the purpose of improving particularly exposure sensitivity (for example, Japanese Patent Application No. 167010/1977, Japanese Laid-Open Patent Publication No. 17358/1981, Japanese Patent Application No. 5233/1982). However, in this prior art, a sufficiently improved characteristic can be obtained with respect to exposure sensitivity, but there is the problem that memory stability is not yet sufficiently satisfactory.
On the other hand, various materials which undergo nonmemorizable electroconductivity variation have been known and utilized as optical switching devices or optical sensors. However, the converting devices of the prior art as mentioned above, while undergoing electroconductivity variation between ON-OFF changes in the relatively lower electroconductivity region, are not sufficiently satisfactory with respect to their switching sensitivity.
DISCLOSURE OF THE INVENTION
The present invention has been accomplished in view of the points as described above, and particularly the following points are objects of the invention.
(a) To provide a material having excellent electroconductivity variation characteristic with respect to the application of light or heat energy.
(b) To provide a memorizable recording material with excellent memory stability having the above material, and a recording-reproducing method by use of the recording material.
(c) To provide a non-memorizable converting device with excellent converting characteristic having the above material, and a detecting method by use of the converting device.
The variable electroconductivity material according to the first form of the present invention comprises a formulation of (a) an electroconductivity variation imparting agent comprising a substance which undergoes structural change between nonionic and ionic structures, reversibly or irreversibly, by light or heat energy and (b) a charge transport substance which is changed in electroconductivity by the structural change of said electroconductivity variation imparting agent.
The memorizable recording material according to the second form of the present invention comprises a memorizable converting layer obtained by formulating (a) an electroconductivity variation imparting agent comprising a substance which undergoes structural change between nonionic and ionic structure
REFERENCES:
patent: 3958207 (1976-05-01), Tutihasi
patent: 4148968 (1979-04-01), Nagashima et al.
patent: 4172180 (1979-10-01), Takeda
patent: 4281053 (1981-07-01), Tang
patent: 4338222 (1982-07-01), Limburg et al.
patent: 4346157 (1982-08-01), Kakuta
patent: 4353971 (1982-10-01), Chang et al.
patent: 4557856 (1985-12-01), Miyakawa et al.
patent: 4745301 (1988-05-01), Michaelchik
patent: 4780790 (1988-10-01), Takimoto et al.
Inoue Eiichi
Noshiro Atsumi
Utsumi Minoru
Dai Nippon Insatsu Kabushiki Kaisha
Welsh J. David
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