JPH0675367A - Microcapsule and image recorder - Google Patents

Abstract

(57) [Abstract] [Purpose] It is intended to contribute to reduction in size and weight of an apparatus by enabling development under pressure at low pressure. [Structure] The microcapsule 1 is composed of an outer shell portion 2 and a liquid component 3, and the outer shell portion 2 has conductivity. A voltage is applied between the holding member 44 and the transfer member 45 by the power source E, and in this pressure developing step, the outer shell 2 is heated by Joule heat and its strength is deteriorated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording device such as a copying machine or a printer and its microcapsule.

[0002]

2. Description of the Related Art Conventionally, a toner composed of microcapsules, in which a photosensitive material composed of a dye or pigment and a photocurable material is encapsulated in the outer wall of a resin and the mechanical strength of which is changed in response to light, has been known. JP-A-3-77961 and JP-A-3-8
It is disclosed in Japanese Patent No. 0258. Further, using the toner composed of the microcapsules, after exposing the toner, only the weak toner is destroyed by pressure or the like,
An image forming apparatus for forming an image on an image receiving paper by flowing out the encapsulated dye body and transferring it to the image receiving paper is disclosed in Japanese Patent Application Laid-Open No. Hei 3 (1999) -311.
-80258 and Japanese Patent Laid-Open No. 3-92856.

In this image forming apparatus, a toner application mechanism for charging the toner, holding it on a carrier, and adhering it to a support by electrostatic force, means for exposing microcapsule toner according to image information, and the pigment body Has a capsule breaking means for spilling. The application mechanism applies the microcapsule toner to the holding member. Next, among the microcapsule toners imagewise exposed by the exposing means, the microcapsule toners which have not been photo-cured are destroyed by the destroying means and the inclusions such as pigment bodies flow out, so that the image is received on the image receiving paper. It is formed.

[0004]

However, the following problems have occurred in the image recording apparatus configured as described above. That is, when the microcapsule toner is broken by the breaking means, a large amount of pressure is required. Since the microcapsule toner is a fine particle of 10 microns or less, it is very difficult to be crushed, and pressure is indispensable for releasing the encapsulated pigment body. For this reason, the image recording apparatus provided with the destruction means capable of uniformly applying a high pressure is inevitably increased in size or weight, and cannot be made into a small and lightweight device.

Furthermore, in order to improve the resolution and to protect the image,
It has become necessary to make microcapsule toner particles smaller and thicker wall materials. Therefore, further pressure is required to break the microcapsules, which is a very serious problem.

The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to make it possible to reduce the size and weight of the device by breaking the microcapsules with a small pressing force.

[0007]

In order to achieve this object, the microcapsule and the image recording apparatus of the present invention have the following features.

That is, the microcapsules are composed of at least an image-forming material such as a dye precursor which changes color by reacting with a color-forming substance such as a dye or a pigment or a developer, and a photosensitive substance which is cured by light energy. With inclusions,
It is composed of a wall material surrounding the inclusion. The wall material of the microcapsules is electrically conductive.

Further, the image recording apparatus uses a microcapsule composed of at least a conductive wall material and an image forming material, and a pressurizing means for causing the image forming material to flow out, and a microcapsule for the pressurizing means. It has holding means for supplying capsules. Further, it is characterized in that a means for applying a current causing damage to the wall material is provided between the pressurizing means and the holding means.

[0010]

With the microcapsule and the image recording apparatus of the present invention having the above-mentioned structure, the microcapsule is easily broken by being energized during pressure development of the microcapsule. As a result, pressure development is possible even at low pressure, and the size and weight of the apparatus can be reduced.

[0011]

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 sectional view of the microcapsule of the present invention. The microcapsule 1 includes an outer shell portion 2 and a liquid component 3 inside the outer shell portion 2.

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 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 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 microcapsule 1 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.
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.

Now, the outer shell 2 will be described.
Materials for forming the outer shell 2 include gelatin, gum arabic, starch, sodium alginate, polyvinyl alcohol, polyethylene, polyamide, polyester, polyurethane, polyurea, polyurethane, polystyrene, nitrocellulose, ethyl cellulose, methyl cellulose, melamine-formaldehyde resin, urea- A resin suitable for microencapsulation such as formaldehyde resin is usually used, and a conductive material such as carbon or fine metal powder is added to the inside of the resin. Thereby, the outer shell portion 2 is provided with conductivity. Further, as the resin of the outer shell, polyacrylonitrile, which is a polymer compound having a long conjugated system, may be used to generate conductivity.

Next, the microcapsule 1 having the above structure is
An example used in an image forming apparatus 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, there are provided a capsule holding member 44, a microcapsule applying section 20 for applying the microcapsules 1 to the capsule holding member 44, an exposing section 10, and a transfer member 45.

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. Furthermore, 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 is made of metal such as stainless steel or aluminum. If necessary, a resin material for adding a function may be coated or bonded around the core portion. The holding member 44 is connected to a power source E capable of applying a positive voltage. The transfer member 45 is grounded. The capsule holding member 44 and the transfer member 4
The region sandwiched by 5 constitutes the destruction portion 42 of the microcapsule.

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 the color tone of an image, and a light shielding plate 19.

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

Next, the operation of this apparatus will be described with reference to FIG. FIG. 3 is a detailed explanatory diagram showing the behavior of the microcapsules.

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 microcapsule 1 is 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 (FIG. 3A).

The holding member 44 coated with the microcapsules 1 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 platen glass 15 supporting the original 12 is moved. As a result, the exposure operation is performed according to the original 12. The light reflected from the original 12
An image is formed on the surface of the microcapsule 1 applied to the holding member 44 through the filter 14 for adjusting the color tone of the image.

The microcapsules 1 exposed according to the image information as described above are cured due to the polymerization reaction of the liquid component 3 according to the degree of the exposure energy, and become the cured capsules 4 (FIG. 3 (b)). ).

Further, the microcapsule 1 has a destruction portion 42.
Be transported to. Here, the microcapsule 1 is sandwiched between the holding member 44 and the transfer member 45, and pressure is applied while energizing between them. At this time, when current flows,
Since the outer portion 2 of the microcapsule has conductivity, particularly the organic component of the outer portion 2 is deteriorated. That is,
The organic matter having conductivity is thermally deteriorated by Joule heat generated when electricity is applied, or is forced to be electrically oriented, and its strength is weakened. Further, when an electric current flows through the conductive material portion, the insulating organic component also undergoes dielectric breakdown, and the outer shell portion 2 deteriorates (FIG. 3 (c)).

Of the pressurized microcapsules,
Microcapsules 1 with low degree of exposure by the above-mentioned exposure
Are destroyed and the image forming material or the like flows out according to the exposure amount. At this time, since the microcapsule 1 and the transfer member 45 are in contact with each other, the effluent is transferred to the transfer member 45.

At this time, since the microcapsules are deteriorated to cause reduction in strength as described above, it is possible to reduce the pressure required for the pressure development. Furthermore, since the strength deterioration in this embodiment occurs only in the outer portion, the strength deterioration of the inclusion cured by exposure does not naturally occur. Therefore, the contrast in strength between the cured capsule and the uncured capsule can be increased as compared with the conventional case.

Further, the image forming material is transferred from the transfer member 45 to the image receiving paper 52 (FIG. 3 (d)), an image is formed, and then it is fixed and discharged to the outside of the apparatus (FIG. 3).
(E)).

The microcapsules that have been completely exposed by the image exposure are not destroyed because they remain in the holding member 44 because the liquid component 3 is polymerized, and are peeled off from the holding member 44 by the blade 31 of the cleaning unit 30 and collected. To be done.

The present invention described above is not limited to the above-described embodiments, but can be modified within the scope of the invention. Although a DC voltage is applied between the transfer member and the support member in this embodiment, an AC voltage may be applied.

[0036]

As is apparent from the above description, the microcapsules and the image recording apparatus of the present invention are easily broken by being energized during pressure development of the microcapsules. As a result, pressure development is possible even at low pressure, and the size and weight of the apparatus can be reduced.

[Brief description of drawings]

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

FIG. 2 is a schematic sectional view of the image recording apparatus of the present invention.

FIG. 3 is an enlarged explanatory diagram showing the behavior of microcapsules.

[Explanation of symbols]

 1 Micro Capsule 2 Outer Shell 3 Liquid Component 20 Micro Capsule Applying Section 44 Holding Member 45 Transfer Member E Power Supply

Claims (2)

[Claims] 1. An inclusion comprising at least 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 developer, and a photosensitive substance that is cured by light energy. A microcapsule constituted by a wall material surrounding the inclusion, wherein the wall material of the microcapsule has conductivity. 2. A microcapsule composed of at least an electrically conductive wall material and an image forming material is used, and pressurizing means for causing the image forming material to flow out, and holding for supplying the microcapsule to the pressurizing means. An image recording apparatus having a means, characterized in that means for applying a current that causes damage to the wall material is provided between the pressing means and the holding means.