JPH0392859A - Recording medium - Google Patents

Abstract

PURPOSE:To obtain a recording medium having photosensitive pressure- responsive microcapsules hardenable in short-time exposure by enclosing at least a photohardenable resin, a photopolymerization initiator, a light-storing dye in the microcapsules held on the support of the recording medium. CONSTITUTION:The support 12 of the recording medium 10 is made of natural or synthetic paper, plastic film, or metal foil, and the microcapsules enclose the photohardenable resin, the photopolymerization initiator, the light-storing dye, and a dye precursor. The side of the support 12 holding the microcapsules 11 of the recording medium 10 exposed in accordance with image information sent from a computer in the main body of a printer is brought into contact with the color developer holding side of the color developing medium 20 and pressed with pressing rollers 105 to form an image in the color developing medium 20, for example, by exposing the whole area of size A4 in about 20sec, thus permitting the obtained recording medium of the photosensitive microcapsule type to be hardened only in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photosensitive and pressure-sensitive recording medium that records image information and the like using microcapsules that harden in response to light.

[Prior art 1] Conventionally, microcapsules in which a photocurable resin that cures in response to light and a dye precursor are encapsulated inside are provided on the surface of a sheet-like support, and image information is transmitted depending on the cured state of the microcapsules. Recording media for recording are known. In this type of recording medium, the photocurable resin is cured by light and the microcapsules become rigid, so the surface is usually exposed to light according to the image information, and the internal parts are destroyed by exposing the microcapsules that have not been hardened by the exposure. It is used in a copying device that forms an image on a recording medium or transfer sheet by reacting a dye precursor with a color developer coated on the surface of the recording medium or a transfer sheet.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a recording medium in which photosensitive and pressure-sensitive microcapsules are hardened by short-time exposure such as laser direct exposure, The aim is to enable the digitization of records.

[Problems to be Solved by the Invention] However, with conventional recording media, as shown in FIG. 3, the sensitivity decreases with short exposure due to the non-reciprocity law.

For example, if an attempt is made to create an image using laser direct exposure, if the exposure time is 300 dpi and 1 dot is 1 second, the time required to fully expose an A4 size sheet is about 2,500 hours, which is impractical.

[Function] According to the recording medium of the present invention having the above configuration, the microcapsules on the support contain at least a photocurable resin, a photopolymerization initiator, and a phosphorescent dye, so that short-term exposure such as laser direct exposure is possible. Even when exposed to light, the photosensitive microcapsules harden because the phosphorescent dye absorbs light and gradually emits light.

[Means for Solving the Problems] In order to achieve this object, the recording medium of the present invention provides that the microcapsules supported on the support of the recording medium contain at least a photocurable resin, a photopolymerization initiator, Contains luminescent dye.

[Example] Hereinafter, examples embodying the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a recording medium of the present invention, and FIG. 2 is a sectional view of a color developing medium.

The recording medium 10 in FIG. 1 has a structure in which microcapsules 11 are coated on a support 12, and the color developing medium 20 in FIG. 2 has a structure in which a color developer 21 is coated on a base sheet 22. There is. Although a so-called separate type in which the recording medium 10 and the color developing medium 20 are separated is illustrated here, a self-contained type in which microcapsules and a color developer are simultaneously coated on a support may also be used.

Specifically, the support 12 of the recording medium 10 may be made of natural paper, laminated paper, plastic film, metal foil, or the like.

Although the microcapsule 11 is not shown, in the capsule wall,
The microcapsules contain a photocurable resin, a prepolymerization initiator, a luminescent dye, and a dye precursor, and can be produced by a well-known method such as a coacervation method or an interfacial polymerization method. As the photocurable resin, any photopolymerizable substance can be used, such as 2-ethylhexyl acrylate, 2-hydroxybrobyl acrylate, 1,3-butanediol acrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, etc. Examples include acrylate. In addition, photopolymerization initiators include penzophenone, xanthone, thioxanthone, halogenated baraffin, penzoin alkyl ether, etc., and dye precursors include triarylmethane compounds, bisphenylmethane compounds, xanthene compounds, thiazine compounds, spiropyran compounds, etc. As the phosphorescent dye, a mixture containing alkaline earth metal sulfide, zinc sulfide, etc. as main components and a trace amount of heavy metal added thereto can be used.

Next, the color developing medium 20 will be described. The base sheet 22 can be made of natural paper, synthetic paper, plastic film, etc., and the color developer 21 can be any substance that develops color by reacting with the colorless dye precursor in the microcapsules 11. Examples include acid clay, activated clay, inorganic acids such as kaolin, phenolic compounds such as P-phenylphenol, and aromatic carboxylic acid compounds such as salicylic acid, gallic acid, and probyltannic acid. Can also be used in combination.

In this example, acid clay, bisphenol A, and P-phenylphenol were used as the color developer 21 of the color developer medium 20.

First, 50 parts of acid clay, 30 parts of bisphenol A, P-
30 parts of phenylphenol was dispersed in 60 parts of an aqueous solution of polyvinyl alcohol as a binder to make a color developer dispersion solution, which was applied to natural paper with a paper thickness of 110 μm, dried with hot air at 80°C for 40 seconds in the open air, and developed into a developer with a color developer of 15 μm. A colorant layer was formed.

Next, a method of manufacturing the recording medium 10 will be explained.

100 parts of trimethylolbroban triacrylate as a photocurable resin, penzophenone as a photopolymerization initiator,
Microcapsules were obtained by a coacervation method using 2.5 parts of Michler's ketone, 3 parts of crystal violet lactone as a dye precursor, and 3 parts of zinc sulfide (Zns-Ag) containing a trace amount of silver as a luminescent dye. The luminescent dye is made by adding 1 mole (mol) of purified zinc sulfide (ZnS) to 10-4 mole (mol) of silver (Ag) as an activator.
and potassium chloride (K C #) as a fluxing agent of 0.1
It was prepared by adding mol (mol) of the mixture, heating it to 1200°C in a quartz crucible, and holding it for 1 hour. The obtained microcapsules were coated on a 20 μm polyethylene terephthalate film and dried.

Here, when manufacturing capsules, a photopolymerization initiator, a dye precursor,
By combining phosphorescent dyes, it is possible to produce yellow, magenta, and cyan colors, and full color production is possible with the three-color capsule.

Specifically speaking, the phosphorescent dyes that can be used include zinc sulfide (ZnS-Cu) containing a trace amount of copper (green luminescence), zinc sulfide (ZnS-Ag) containing a trace quantity of silver (blue luminescence), and a trace amount of lead. Zinc sulfide (ZnS-Pb) containing (blue-green luminescence), zinc sulfide (ZnS-Mn) containing a trace amount of manganese (orange luminescence)
etc.

FIG. 4 briefly describes a laser printer using the recording medium of the present invention. First, the computer inside the printer (
(not shown), the light emitted from the laser beam oscillator is irradiated onto the optical scanning mirror 103 via the condensing lens 102, and the light irradiated onto the optical scanning mirror 103 is transmitted via the fθ lens 104. It is configured so that the surface of the recording medium 10 is directly scanned.

The thus exposed microcapsule-carrying surface of the recording medium 10 and the developer-carrying surface of the color-developing medium 20 are brought together and pressed by the pressure roller 105, thereby forming an image on the color-developing medium 20. Since the microcapsules can be cured with exposure of 2 μs per dot at 300 dpi, the entire surface of an A4 size sheet can be exposed in about 20 seconds.

Incidentally, although examples in which the effects of the recording medium of the present invention are noticeable have been described above, the recording medium is not limited to this, and can be used in reflective type and transmission type copying devices, and can be cured by exposure to light during short periods of sunlight. Therefore, the hardening is large.

[Effects of the Invention] As is clear from the detailed description above, according to the present invention, the photosensitive microcapsules supported on the support contain at least a photocurable resin, a photopolymerization initiator, and a luminescent dye. Therefore, it is possible to provide a recording medium in which photosensitive microcapsules are cured even with short exposure. Using this technology, high-speed image recording becomes possible, and furthermore, digitization using laser direct exposure becomes possible.

[Brief explanation of drawings]

1 to 4 show embodiments embodying the present invention. FIG. 1 is a sectional view of a recording medium of the invention, FIG. 2 is a sectional view of a color developing medium, and FIG. 3 is a sectional view of a color developing medium. FIG. 4, which is a diagram showing the reciprocity law irregularity of a conventional recording medium, is a schematic diagram of a printer using the recording medium of the present invention. In the figure, 10 is a recording medium, 11 is a microcapsule, 12
is a support.

Claims (1)

[Claims] 1. A recording medium comprising photosensitive microcapsules supported on a support, characterized in that the microcapsules contain at least a photocurable resin, a photopolymerization initiator, and a luminescent dye. recording medium.