JPH05323593A - Photosensitive capsule - Google Patents

Abstract

PURPOSE:To prevent the reduction in sensitivity, and also to enhance coloring density by phase-separating a photosensitive capsule into a picture-image forming material agglomerate in which a picture-image forming material is agglomerated, and a photosensitive part in which the picture-image forming material is thin. CONSTITUTION:A photosensitive capsule 10 is made up of an outer circumferential part 11 and an internal part 12, and the internal part 12 is further phase- separated into a coloring material agglomerate 13 and a photosensitive part 14. As the coloring material constituting the coloring material agglomerate 13, a color precursor or the like that changes color when it reacts with color, pigment, developer, or the like may be used, and a plurality of them may exist. The photosensitive part 14 is such a resin that reacts to light and denaturates such as photosoftening and photohardening resins. The photo-setting, resin is usually used by mixing a photoinitiator with a polymerizing material. There are, for example, benzophenone, benzoil alkyl ethers such as benzoil isopropyl ether, Michler's ketone, metallic arene compound, 2,4-diethylthioxanthone, or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive capsule used in an image forming apparatus such as a copying machine or a printer.

[0002]

2. Description of the Related Art Conventionally, a photosensitive capsule which contains an image forming material such as a dye precursor, a dye or a pigment in an outer wall portion made of a resin or the like and has a mechanical strength which changes in response to light has been disclosed. It is disclosed in Japanese Laid-Open Patent Publication No. 63-269146. Further, an image receiving paper is provided by using a photosensitive capsule which contains the image recording material and whose mechanical strength changes in response to light, and after exposing the capsule, destroys only weak toner by pressure or the like. An image forming apparatus for forming an image on a sheet is disclosed in Japanese Patent Laid-Open No. 63-316038.

This image forming apparatus is an image forming apparatus which forms an image on an image receiving paper by a developing method in which the capsule is exposed in accordance with image information, and only a weak toner is destroyed by pressure or the like.

[0004]

However, in the photosensitive capsules used in these image forming apparatuses,
Dye precursors, dyes, image forming materials such as pigments and photosensitive materials whose mechanical strength changes in response to light are contained in the capsule in a uniformly mixed or compatible state.
The following problems have occurred.

The first problem is that, when light is emitted in accordance with image information, the image forming material uniformly dispersed in the inclusion absorbs light having a wavelength absorbed by the photosensitive material. Therefore, there is a problem that the sensitivity is significantly reduced.

A second problem is that a large amount of photosensitive material is present in the image forming material when an image is formed, and fine primary particles or dissolved image forming material destroys the photosensitive capsule. The image forming material adheres to the inside of the outer wall portion when the image is formed by the image forming method, which causes a problem that the color density of the formed image is insufficient.

Further, the third problem is that, particularly in a system using photocuring, the capsule of the portion (corresponding to the white background portion of the formed image) which is not photocurable and should not release the image forming material is, Due to the presence of the image forming material, the curing reaction is hindered, the photosensitive material is not sufficiently polymerized and remains rubbery, and the strength is insufficient. is there.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a light-sensitive capsule which prevents a decrease in sensitivity due to the presence of an image-forming material and has an excellent color density. ..

[0009]

To achieve this object, the photosensitive capsule of the present invention contains at least an image forming material such as a dye or a pigment and a photosensitive material whose mechanical strength is changed by the irradiation of electromagnetic waves. As a product, a photosensitive capsule contained in the outer wall portion made of resin or the like, and further,
The inclusion is phase-separated into an image forming material aggregate in which the image forming material is aggregated and a photosensitive portion in which the image forming material is thin.

The image-forming material aggregate is preferably located in the center of the photosensitive capsule.

Further, the agglomerate of the image forming material may be located in contact with the inside of the outer wall portion.

[0012]

The photosensitive capsule of the present invention having the above structure is
The inclusions are phase-separated into an image forming material aggregate in which the image forming material is aggregated and a photosensitive portion in which the image forming material is diluted.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the structure of a photosensitive capsule 10 which is a first embodiment of the present invention.

The photosensitive capsule 10 is composed of an outer shell portion 11 and an inner envelope 12, which is further phase-separated into a coloring material aggregate 13 and a photosensitive portion 14. The outer diameter of the photosensitive capsule 10 is preferably several μm to several tens of μm,
The particle size of the color material aggregate 13 is preferably two thirds or less of that of the photosensitive capsule 10. However, it is not limited to this. A plurality of the color material aggregates 13 may be present.

As the color material forming the color material aggregate 13, a dye precursor or the like which changes color by reacting with a dye, a pigment, a color developer or the like can be used. As the dye, xanthene-based, coumarin-based, merocyanine-based, thiazine-based, azine-based, methine-based, oxazine-based, phenylmethane-based, cyanine-based,
Azo-based, anthraquinone-based, pyrazoline-based, stilbene-based, quinoline-based, phthalocyanine-based, leuco dyes and the like can be mentioned, and examples of the pigment include carbon black, yellow lead, red iron oxide, titanium oxide, molybdenum red and other inorganic pigments and organic pigments Be done. Further, as the dye precursor, a diphenylmethane compound, a triphenylmethane compound, a bisphenylmethane compound, a xanthene compound, a thiazine compound, a fluorane compound, a spiropyran compound, or the like and a mixture thereof can be used. When the dye precursor is used as the image forming material, it is necessary to use the color developer as the absorbing layer.

The photosensitive portion 14 is a resin that is sensitive to light and is modified, and includes a photosoftening resin and a photocurable resin. The photocurable resin is usually used by mixing a photoinitiator and a polymerizable substance. The photoinitiator is one which is sensitive to light and initiates the polymerization of the resin, for example, benzophenone, benzoyl alkyl ethers such as benzoyl isopropyl ether, Michler's ketone, metal arene compound,
2,4-diethylthioxanthone and the like can be mentioned.

Examples of the polymerizable substance include N-vinyl-2-pyrrolidone, bisphenol A diacrylate and methacrylate, tripropylene glycol diacrylate and methacrylate, polyethylene glycol diacrylate and methacrylate, pentaerythritol triacrylate and methacrylate,
Examples include dipentaerythritol hexaacrylate and methacrylate, trimethylolpropane triacrylate and methacrylate, oligoester acrylate and methacrylate and the like. In addition, these polymerizable compounds may be used alone or as a mixture of two or more kinds.

The photosensitive capsule 10 having the above-mentioned structure can be manufactured by a method which has already been known in the art. For example, US Pat. No. 2,800,457.
Phase separation method from an aqueous solution as shown in JP-B-2800458 and JP-B-2800458, and the interface weights as shown in JP-B-38-1974, JP-B-42-446 and JP-B-42-771. In-situ method by polymerization of monomers shown in Japanese Patent Publication No. 36-9168, JP-A No. 51-9079, and melt-dispersion cooling method shown in British Patent Nos. 952807 and 965074. However, the present invention is not limited to this.

As the material for forming the outer shell portion 11, gelatin, gum arabic, starch, sodium alginate,
Polyvinyl alcohol, polyethylene, polyamide, polyester, polyurethane, polyurea, polyurethane, polystyrene, nitrocellulose, ethyl cellulose, methyl cellulose, melamine-formaldehyde resin, urea-formaldehyde resin, etc. are used, but only the outer shell part 11 is sufficiently exposed to light. It is more preferable to use a material that allows light to pass through.

In the photosensitive capsule 10 having the above structure,
When light is emitted corresponding to the recorded image, the photosensitive portion 1
In 4, the photoreaction proceeds without being hindered by the unnecessary absorption of the coloring material aggregate 13, so that the sensitivity of the photosensitive portion 14 is prevented from being lowered.

Further, in the photosensitive capsule 10 in which the photosensitive portion 14 is hardened, it is covered with the hard film of the photosensitive portion 14, so that it is erroneously destroyed and the coloring material is released to cause image noise. It is possible to obtain sufficient strength that does not occur.

Further, in the capsule in which the photosensitive portion 14 is not cured, the coloring material aggregate 13 is not in contact with the outer portion 11, so that when this is destroyed and an image is formed on an image receiving paper or the like, There is no loss of color material due to adhesion of the color material to the inner wall of the outer shell 11 of the color material aggregate 13, and all the color material aggregates 13 contribute to image formation, so that the color density is not insufficient. As a result, reduction in image density is prevented.

The present invention is not limited to the embodiments described in detail above, and various modifications can be made without departing from the spirit of the invention.

For example, the photosensitive capsule 10 of the present invention is shown in FIG.
The configuration shown in FIG. The configuration will be briefly described below, but components having the same effect will be denoted by the same reference numerals.

In the photosensitive capsule 20 shown in FIG. 2, the color material agglomerate 13 is constructed so as to contact the inner wall surface of the outer shell 11. In this case, when this is destroyed and an image is formed on the image receiving paper or the like, in the capsule in which the photosensitive portion 14 is not cured, the coloring material aggregate 13 and the outer shell 1 are formed.
1 is much smaller than that in the case where the coloring material is in the form of fine primary particles, the photosensitive capsule 1 of the above embodiment
As in the case of 0, the color density does not become insufficient and the image density is prevented from decreasing.

By the way, when an attempt is made to manufacture a capsule having the constitution such as the photosensitive capsule 10 of FIG. 1 or the photosensitive capsule 20 of FIG. 2, a mixture of both is usually obtained. However, as described above, both have the same effect as long as they are used in the similar image forming process, and thus it is not necessary to separate them in the present invention.

[0028]

As is apparent from the above description, according to the photosensitive capsule of the present invention, the contents include the image forming material aggregate in which the image forming material aggregates and the photosensitive portion in which the image forming material is diluted. Since and are phase-separated, unnecessary absorption of irradiation electromagnetic waves by the image-forming material does not occur in the photosensitive portion, and thus the sensitivity of the photoreaction in the inclusion is not reduced, and the image-forming material aggregates. Therefore, the color density can be easily obtained.

Further, according to the above constitution, since the thick film of the photosensitive portion is formed inside the photosensitive capsule, the strength of the cured photosensitive capsule is increased and the image forming material is originally released. It is possible to provide a photosensitive capsule capable of preventing an erroneous destruction of a cured photosensitive capsule, which should not be performed, during the image forming process, and capable of forming an image with excellent contrast.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of a photosensitive capsule of the present invention.

FIG. 2 is a schematic view showing a second embodiment of the photosensitive capsule of the present invention.

[Explanation of symbols]

 10 Photosensitive Capsule 11 Outer Shell 12 Encapsulation 13 Coloring Material Aggregate 14 Photosensitive Part 20 Photosensitive Capsule

Claims (3)

[Claims] 1. A photosensitive capsule containing at least an image forming material such as a dye or a pigment and a photosensitive material whose mechanical strength is changed by irradiation of electromagnetic waves as an inclusion in an outer wall portion made of a resin or the like. The photosensitive capsule is characterized in that the inclusion is phase-separated into an image-forming material aggregate in which the image-forming material is aggregated and a photosensitive portion in which the image-forming material is diluted. 2. The photosensitive capsule according to claim 1, wherein the image forming material aggregate is located in the center of the photosensitive capsule. 3. The photosensitive capsule according to claim 1, wherein the image forming material aggregate is located in contact with the inside of the outer wall portion.