JPH063817A - Microcapsule and image forming device - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a microcapsule and an image forming apparatus that can be broken without using a high pressure. [Structure] The microcapsule 1 is composed of an outer shell portion 2, a liquid component 3 inside the outer shell portion 2, and a needle-shaped magnetic material 4. The liquid component 3 contains at least a photocurable substance that cures in response to a predetermined wavelength and an image forming material such as a dye or a pigment. Inside the image forming apparatus 60, a capsule holding member 44, a microcapsule applying section 20 for applying the microcapsule 1 to the capsule holding member 44,
The exposure unit 10 and the transfer member 45 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive microcapsule used in a copying machine, a printer and the like and an image forming apparatus using the microcapsule.

[0002]

2. Description of the Related Art Conventionally, a photosensitive sheet coated with microcapsules encapsulating a dye precursor and a photo-curable substance is exposed based on image information by using an exposing means, and the microcapsules are exposed based on the image information. After curing, the microcapsules that have not been cured are crushed by pressure development in a state of being in 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 image forming apparatus has been put into practical use in which an image is formed by reacting a dye precursor flowing out from a microcapsule with a roller and a color developer.

Further, since the image forming apparatus requires a developer because it uses a dye precursor, Japanese Patent Application No. 3-12491, which the applicant of the present invention has already filed.
9, No. 3-124920, No. 3-124921
In the application such as Japanese Patent No. 3,099,037, an image forming apparatus using a colored micro-pell toner containing a dye or a pigment which does not require a developer is proposed.

[0004]

However, in the conventional image forming apparatus, in order to sufficiently destroy the microcapsules which have not been cured after exposure, extremely high pressure is required and uniform pressing is required. It was Therefore, there is a problem that the pressurizing device becomes large in size, or when plain paper or the like is sandwiched and pressed, the thickness of the paper changes before and after pressing.

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 microcapsule of the present invention is formed with an image of a dye precursor or the like which changes color at least by reacting with a color-forming substance such as a dye and a pigment or a developer. It is characterized by including a material, a photosensitive substance whose mechanical strength is changed by receiving light energy, and a needle-shaped magnetic material.

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 applying the microcapsules. It is characterized in that a magnetic field generating means for applying a magnetic field from the outside is provided.

[0008]

In the microcapsule of the present invention having the above structure, it is possible to destroy the capsule from the inside of the microcapsule by vibrating the encapsulated needle-shaped magnetic material by the magnetic field generating means. Therefore,
There is no need to break the microcapsules with a pressure roller having an extremely high pressure as in the past. Alternatively, the pressure roller is not needed. When such a microcapsule is used in an image forming apparatus or the like, the apparatus can be made smaller and lighter.

[0009]

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

FIG. 1 shows an enlarged cross-sectional view of the microcapsule of this embodiment. The microcapsule 1 includes an outer shell portion 2, a liquid component 3 inside the outer shell portion 2, and a needle-shaped magnetic material 4.

The liquid component 3 contains at least an image forming material such as a dye or a pigment, and a photosensitive substance whose mechanical strength changes in response to a certain wavelength.

As the image forming material, a dye precursor or the like that 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, Examples thereof include leuco dyes, and examples of pigments include inorganic pigments such as carbon black, yellow lead, red iron oxide, titanium oxide, and molybdenum red, and organic pigments. Further, as the dye precursor, a diphenylmethane compound, a triphenylmethane compound, a bisphenylmethane compound, a xanthene compound, a thiazine compound,
Fluoran compounds, spiropyran compounds, etc. and mixtures 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 substance is a resin that 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 that is sensitive to light and initiates polymerization of the resin, and for example, benzophenone, benzoyl alkyl ethers such as benzoyl isopropyl 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. Further, these polymerizable compounds may be used alone or as a mixture of two or more kinds.

The needle-shaped magnetic material is composed of carbon steel, alloy steel, alnico alloy, cobalt magnet, iron oxide, ferrite, etc., and its length is about 20 to 30% of the capsule particle size. Desirable, even the longest is 50
% Or less is desirable. Since such needle-shaped magnetic materials have already been commercialized and sold by various companies, they can be easily obtained.

The microcapsule 1 having the above structure can be manufactured by a method which has already become a known technique in the art. For example, US Pat. No. 2,800,457.
No. 2,400,458 and the like, a method of phase separation from an aqueous solution as described in JP-B-38-1974 and JP-A-4
No. 2-446, No. 42-771, etc., interfacial polymerization method, JP-B-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 5074, it is not limited to this.

The material for forming the outer shell 2 is 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 of this embodiment will be described with reference to the drawings.

FIG. 2 is a schematic sectional view of an image forming apparatus 60 using the microcapsules 1.

Inside the image forming apparatus 60, a capsule holding member 44, a microcapsule applying section 20 for applying the microcapsule 1 to the capsule holding member 44, an exposing section 10, and a transfer member 45 are provided.

Capsule holding member 44 and transfer member 4
5 are both columnar or cylindrical in shape, and the size thereof is not limited, but for example, diameter 30 mm to 200
Length in mm (length in the direction perpendicular to the paper surface in Fig. 2) 3
It is about 00 mm. Further, the holding member 44 contains a magnet 40 for applying a magnetic field to the microcapsule 1. The magnet 40 can vibrate, and the magnet 40
The needle-shaped magnetic material 4 encapsulated in the microcapsule 1 is vibrated by vibrating the above, and the capsule is destroyed from inside the capsule. In the conventional device, since the holding member 44 and the transfer member 45 need to withstand the pressure applied to break the microcapsules, at least the core portion needs to be made of metal such as stainless steel or aluminum. However, this is not necessary in the present embodiment, and any material that does not interfere with the magnetic field of the magnet 40 may be used. In the area sandwiched between the capsule holding member 44 and the transfer member 45, the microcapsules can be broken and transferred to plain paper at the same time.

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

The microcapsule coating section 20 is provided for dry-coating the holding member 44 with microcapsules, and a case 21 for storing the microcapsules 1, a stirrer 23, and a carrier 2 carrying the microcapsules.
5 and a supply body 24 for supplying microcapsules to the support body 25. Here, an electric field for moving the microcapsules 1 from the microcapsule carrier 25 to the holding member 44 is formed between the holding member 44 and the microcapsule carrier 25 by a DC or AC power supply (not shown). Has been done.

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 supply body 24. The carried microcapsule 1 includes the holding member 44 and the carrier 25.
An electrostatic attraction is applied in the direction of the holding member 44 by the electric field formed between the two. 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. In the microcapsule applying section 20, it is also possible to adhere the microcapsules to the holding member 44 by using a magnetic field instead of using electrostatic force. However, if a magnetic field is used during capsule application, the capsule may be broken by the encapsulated needle-shaped magnetic material 4. Therefore, in the present embodiment, an application method other than the magnetic field such as electrostatic application is used. Is desirable.

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

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.
Be 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 magnetic field is applied to the microcapsule 1 from the inside of the holding member 44 by the magnet 40, and the magnet 40 vibrates. With this,
The needle-shaped magnetic material 4 contained in the microcapsule 1 vibrates. Due to the vibration of the needle-shaped magnetic material 4, the microcapsules having a low degree of exposure due to the image exposure have a higher vibration than the microcapsules having a high degree of exposure and undergoing a polymerization reaction of the inclusions. The outer shell 2 is pierced and destroyed from the inside (FIG. 3). Since the image forming material flows out along with the destruction from the inside, an image is formed on the plain paper 52. Since the microcapsule is capable of self-destruction, it is sufficient that the transfer portion 45 and the holding member 44 are in contact with each other at low pressure.

The image receiving paper 52 on which the image is formed is heated by the heating lamp 55, and the image is thermally fixed on the image receiving paper 52.
After that, it is carried out from the outlet 56.

The microcapsules that have been exposed and cured by the image exposure remain undestructed in the holding member because the encapsulated substances are polymerized, and are stripped 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, but can be modified within the scope of the invention.

For example, although the microcapsules are dry-coated on the holding member in this embodiment, they may be wet-coated.
Further, although the image is formed on the image receiving paper between the transfer member and the holding member, the structure may be such that the capsule inclusion is once transferred to the transfer member and then transferred from the transfer member to the image receiving paper. Further, the microcapsules having a low degree of exposure by image exposure may be in a state in which the strength of the outer shell portion 2 is deteriorated without being completely destroyed from the inside by the vibration of the needle-shaped magnetic material 4. In this case, the microcapsules are broken between the transfer portion 45 and the holding member 44 which are in contact with each other at a low pressure.

[0034]

As is apparent from the above description,
In the microcapsule and the image forming apparatus of the present invention, the capsule can be broken from the inside of the capsule, so it is not necessary to break the microcapsule with the pressure roller having an extremely high pressure. Alternatively, since the pressure roller is unnecessary, the device can be made smaller and lighter.

[Brief description of drawings]

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

FIG. 2 is a schematic sectional view of an image forming apparatus using the microcapsule.

FIG. 3 is an enlarged view of a state in which a microcapsule is broken from inside.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microcapsule 2 Outer shell 3 Liquid component 4 Needle-like magnetic material 20 Microcapsule application part 44 Holding member 45 Transfer member

Claims (2)

[Claims] 1. An image forming material such as a dye precursor that changes color by reacting with a color-forming substance such as a dye or a pigment or a color developer, a photosensitive substance whose mechanical strength is changed by light energy, and a needle. A microcapsule containing a magnetic material having a shape of a circle. 2. The microcapsule according to claim 1, and at least a magnetic field generating means for applying a magnetic field to the microcapsule from the outside, and an exposing means for forming a chemical latent image by exposing according to image information. An image forming apparatus comprising: