JPH05323560A - Microcapsule and image forming device - Google Patents

Abstract

PURPOSE:To make an image forming device miniature and lightweight by breaking microcapsules with the use of external thermal energy so as to eliminate the necessity of a press roller. CONSTITUTION:Microcapsules 1 conveyed toward a transfer part 45. Simultaneously, an image bearing sheet 52 is taken out from a paper feed cassette 51 and is fed between the transfer part 54 and a holding member 44. In this range, the microcapsules 1 are heated by a heater 40 in the holding member 44. At this time, thermal expansion substance 5 packed in the microcapsules 1 expands. Of the heated microcapsules 1, those having a low degree of exposure under image exposure, cannot resist against an increased internal pressure, and accordingly, the outer shells 2 thereof is broken outward. In association with this outward breakage, image forming materials are also discharged, and accordingly, an image is formed on an ordinary sheet 52. That is, it is sufficient that the transfer part 45 and the holding member 44 make contact with each other under a low pressure, and accordingly, it is possible to eliminate the necessity of a press roller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microcapsule having a means for destroying itself and an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, a photosensitive sheet coated with microcapsules encapsulating a dye precursor and a photocurable substance, etc. is exposed based on image information using an exposing means, and the microcapsules are exposed based on image information. After curing, the microcapsules that have not been cured are pressure-developed in a state of being brought into close contact with a support such as plain paper coated with a color developing agent that reacts with the dye precursor encapsulated in the microcapsules. An apparatus for forming an image by reacting a dye precursor flowing out from a microcapsule and a developer with a crushing roller has been put into practical use.

The above-mentioned image forming apparatus requires a color developer because it uses a dye precursor. However, Japanese Patent Application No. 3-124919 and Japanese Patent Application No. 3-124919, which the applicant of the present invention has already filed. The applications such as Japanese Patent Application Laid-Open Nos. 3-124920 and 3-124921 propose an image forming apparatus using a colored kamicupel toner containing a dye or pigment that does not require a color developer.

[0004]

However, in such an image forming apparatus, an extremely high pressure is required to sufficiently destroy the microcapsules which are not cured after exposure. Therefore, there are problems that the pressurizing device becomes large in size, and that when the plain paper or the like is sandwiched and pressed, the thickness of the paper changes before and after the pressurization.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a microcapsule and an image forming apparatus which can be broken without using a high pressure.

[0006]

In order to achieve this object, the microcapsules of the present invention include at least a photosensitive material which changes its mechanical strength upon receiving light energy, and a dye,
A microcapsule containing an image forming material such as a pigment, characterized in that the microcapsule has means for destroying the microcapsule itself by heat energy from the outside.

Further, the image forming apparatus of the present invention has at least an exposing means for applying light to the microcapsules to form a chemical latent image, and an applying means for dry-coating the microcapsules. A heating means for heating is provided.

[0008]

In the microcapsule of the present invention having the above construction, the microcapsule itself is destroyed by the heat energy from the outside. Therefore, it is not necessary to break the microcapsules with a pressure roller having an extremely high pressure as in the conventional case. Alternatively, the pressure roller is unnecessary. When such a microcapsule is used in an image forming apparatus or the like, the apparatus can be made smaller and lighter, and the cost can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied and applied will be described below with reference to the drawings.

FIG. 1 is a partially enlarged sectional view of a microcapsule 1 embodying the present invention. Microcapsule 1
It is composed of an outer shell 2 and a liquid component 3 inside thereof. The liquid component 3 contains at least an image forming material such as a dye or a pigment, a photosensitive substance whose mechanical strength changes in response to a certain wavelength, and a thermal expansion substance 5 which expands, sublimes or vaporizes by thermal energy. Has been done.

As the image forming material, dyes, pigments and the like can be used. As the dye, xanthene type, coumarin type, merocyanine type, thiazine type, azine type, methine type, oxazine type, phenylmethane type, cyanine type, azo type, anthraquinone type, pyrazoline type, stilbene type, quinoline type, phthalocyanine type, Examples of the pigment include inorganic pigments such as carbon black, yellow lead, red iron oxide, titanium oxide, and molybdenum red, and organic pigments.

The photosensitive substance is a resin which is sensitive to light and is modified, and examples thereof include 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 polymerization of the resin, and for example, benzophenone, benzoylalkyl ethers such as benzoylisopropyl ether, Michler's ketone, metal arene compound, 2,
4-diethylthioxanthone etc. 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 thermal expansion substance 5 is not particularly limited as long as it does not reduce the sensitivity of the photosensitive substance and further does not reduce the color of pigments, dyes and the like. For example, hydrophobic low boiling point solvents, water and the like can be used. Further, the thermal expansion substance 5 is the liquid component 3
May be mixed with or compatible with, or may be insoluble in the liquid component 3 and dispersed in the liquid component 3. Furthermore, either the liquid component 3 or the thermal expansion substance 5 may be microencapsulated.

The microcapsule 1 having the above-mentioned structure can be manufactured by a method which is already known in the art. For example, US Pat. No. 2,800,457.
No. 2,800,458 and the like, a method for phase separation from an aqueous solution, JP-B-38-1974, and JP-A-4
No. 2-446, No. 42-771, etc., interfacial polymerization method, Japanese Patent Publication No. 36-9168, JP-A-51.
I by polymerization of monomers shown in Japanese Patent Publication No. 9079
n-situ method, British Patent Nos. 952807 and 96
Although there is a melt dispersion cooling method and the like shown in the specification of No. 5074, it is not limited to this.

As the material for forming the outer shell 2, gelatin, gum arabic, starch, sodium alginate, polyvinyl alcohol, polyethylene, polyamide, polyester, polyurethane, polyurea, polyurethane,
Polystyrene, nitrocellulose, ethyl cellulose,
Methyl cellulose, melamine-formaldehyde resin,
A urea-formaldehyde resin or the like is used, but a material that allows sufficient light transmission is more preferable.

Next, an embodiment of an image forming apparatus using the microcapsules 1 manufactured as described above will be described.

FIG. 2 is a schematic configuration diagram of the image forming apparatus 7. Inside the image forming apparatus 7, the capsule holding member 4 is provided.
4 and the microcapsules 1 on the capsule holding member 44.
Microcapsule coating section 20 for coating
And a transfer member 45 is provided.

The capsule holding member 44 and the transfer member 45 are both cylindrical or cylindrical in shape, and the size thereof is not limited, but the diameter is, for example, 30 mm to 2 mm.
The length is about 00 mm and the length (length in the direction perpendicular to the paper surface in FIG. 2) is about 300 mm. Further, the holding member 44 has a built-in heating device 40 for applying heat energy to the microcapsules 1 to destroy the microcapsules 1.

In the conventional device, the holding member 44 and the transfer member 45 are required to withstand the pressure applied to break the microcapsules, so at least the core portion is made of metal such as stainless steel or aluminum. Although it was necessary, this is not necessary in the present embodiment, and it is sufficient if it can withstand the heat applied by the heating device 40. In the area sandwiched between the capsule holding member 44 and the transfer member 45, the microcapsules can be destroyed, transferred to plain paper, and fixed at the same time.

The exposure section 10 is composed of an exposure lamp 11, a document table glass 15, a document cover 13, a filter 14 for adjusting the color tone of an image, and a light shielding plate 19.

The microcapsule coating section 20 is provided to dry-coat the holding member 44 with microcapsules and stores the microcapsules 1.
The agitator 23 is composed of a stirrer 23, a carrier 25 for supporting the microcapsules, and a supplier 24 for supplying the microcapsules to the carrier 25. Here, the holding member 4 is controlled by a DC or AC power source (not shown).
An electric field for moving the microcapsules 1 from the microcapsule carrier 25 toward the holding member 44 is formed between the microcapsule carrier 4 and the microcapsule carrier 25.

Next, the operation of this device will be described.
When a start switch (not shown) is turned on, the holding member 44
Starts rotating in the direction of the arrow in the figure.

In the microcapsule coating section 20, the microcapsules 1 are charged and carried on the carrier 25 by the rotation of the agitator 23 and the feeder 24. The carried microcapsule 1 includes the holding member 44 and the carrier 25.
An electrostatic attraction force is applied in the direction of the holding member 44 by the electric field formed between and. As a result, the microcapsules 1 move toward the holding member 44 and adhere to the holding member 44 by electrostatic force. That is, the powdery microcapsules 1 are applied to the holding member 44.

The outer shell 2 of the microcapsule 1 has sufficient strength so that the microcapsule 1 is not destroyed during the above-described operation.

The holding member 44 rotates in the direction of the arrow in the figure, and the microcapsules 1 are conveyed to the lower part of the exposure unit 10. At this point, the halogen lamp 11 of the exposure unit 10 is turned on, and the original 1
The platen glass 15 supporting 2 moves. As a result, the exposure operation is performed according to the original 12. Manuscript 1
The light reflected from 2 passes through the filter 14 for adjusting the color tone of the image, and is imaged on the surface of the microcapsule 1 applied to the holding member 44.

The microcapsules 1 exposed according to the image information as described above are cured due to the polymerization reaction of the inclusions according to the degree of the exposure energy.

Further, the microcapsule 1 has a transfer section 45.
Is transported to. At the same time, the image receiving paper 52 is taken out from the paper feeding cassette 51 and sent between the transfer member 45 and the holding member 44. In this region, the microcapsule 1 is heated from inside the holding member 44 by the heating device 40. At this time, the thermal expansion material 5 contained in the microcapsule 1 expands. Among the heated microcapsules 1, the microcapsules with a low degree of exposure by image exposure cannot withstand the increase in internal pressure, and the outer shell portion 2 is destroyed from the inside. Since the image forming material also flows out due to the destruction from the inside, an image is formed on the plain paper 52. Since the microcapsules can be self-destructed by heating, the transfer portion 45 and the holding member 44 need only be in contact with each other at a low pressure.

The microcapsules that have been exposed and cured by the above image exposure remain undestructed and remain on the holding member because the contents of the microcapsules are polymerized, and are peeled off from the holding member 44 by the blade 31 of the cleaning unit 30 and collected. It

The present invention described above is not limited to the above-described embodiments, and changes can be made without departing from the spirit of the present invention.

[0031]

As is clear from the above description,
According to the present invention, it is possible to break the microcapsules without using high pressure.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a microcapsule.

FIG. 2 is a diagram showing an image forming apparatus using microcapsules.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microcapsule 2 Exterior part 3 Liquid component 5 Thermal expansion material 7 Image forming device 10 Exposure part 20 Coating part 40 Heating device 44 Holding member 45 Transfer member

Claims (2)

[Claims] 1. A colored microcapsule containing at least a photosensitive substance whose mechanical strength is changed by receiving light energy and an image forming material such as a dye or a pigment, by applying heat energy to the microcapsule itself. A microcapsule having a means for destroying 2. At least an exposure means for irradiating the microcapsule with light to form a chemical latent image, an application means for dry-coating the microcapsule, and a heating means for heating the microcapsule. An image forming apparatus characterized by.