JPH0377961A - Photosensitive toner - Google Patents

Abstract

PURPOSE:To form an image by using only one kind of simple developing device and to reduce its size by forming microcapsules enclosing a photosensitive resin and a color source and attaching a color developing material for developing the color the source to the surface of each capsule. CONSTITUTION:The photosensitive toner 100 comprises the microcapsules 400 each consisting the inner nucleus 300 containing the photosensitive resin and the color source developing its intrinsic color by reaction with the color developing material and the outer shell 200 enclosing the nucleus 300, and said color developing material 100 covering all over the surface of the shell 200, namely, the microcapsules. Selective exposure of the toner changes the viscosity of the photosensitive resin in the microcapsules to form a latent image, and application of pressure or the like allows the source and the developing material 200 to contact with each other and to develop color, thus permitting an image to be formed on an optional recording medium by using a pair of rollers as a developing device, and accordingly, size reduction and simplification of the device and lowering of cost is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a photosensitive toner whose physical properties change upon irradiation with light.

[Prior Art] Conventionally, as shown in Japanese Patent Application No. 63-320242,
An apparatus has been proposed that records an image on any recording medium by electrostatically applying a photosensitive capsule toner and a color developer toner onto the recording medium, exposing and developing the image.

According to this apparatus, compared to the conventional method of recording images using a photosensitive recording medium and an image-receiving sheet, consumables are used more effectively, so that copying costs can be reduced.

[Problems to be Solved by the Invention] However, in this apparatus, a photosensitive capsule toner developing device that applies photosensitive capsule toner to a photoreceptor;
It is necessary to have two types of developing devices: a developer toner developer for applying color developer toner, and the structure of the device is complicated, making it difficult to miniaturize and also making it difficult to control its operation.

The present invention has been made in order to solve the above-mentioned problems, and it is an image forming apparatus using photosensitive toner that has only one type of developing device, thereby making it possible to downsize the apparatus. The purpose is to provide photosensitive toner.

[Means for Solving the Problems] In order to achieve this object, the photosensitive toner of the present invention includes microcapsules containing a photosensitive resin and a chromogen;
It has a color developing substance that develops color from the chromogen supported on the surface of the microcapsule.

[Function] When the photosensitive toner of the present invention having the above structure is selectively exposed to light, the viscosity of the photosensitive resin therein changes to form a latent image, and the photosensitive toner in the unexposed area changes. The chromogen and color developer come into contact with each other under pressure or the like to develop color and form an image on any recording medium.

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

FIG. 1 is an enlarged cross-sectional view of the photosensitive toner of the present invention. The photosensitive toner 100 includes a microcapsule 400 in which an inner core 200 made of a photosensitive resin and a chromogen that develops color by reacting with a color developer is contained by a capsule outer shell 300.
It has a structure in which the surface of the color developer material 500 is covered.

The photosensitive resin included in the photosensitive toner of the present invention includes a silicate acid residue, a cinnamylidene residue, an α, β-unsaturated ketone residue, a coumarin residue, an anthracene residue, and an α-phenylmaleimide residue. , photodimerizable resins with photosensitive groups such as benzophenone residues and stilbene residues, photodegradable resins with photosensitive groups such as diazonium salt residues, quinonediazide residues, azide residues, dithiocarbamate residues, benzoin residues, etc. A photopolymerizable resin having an acryloyl group, an allyl group, a vinyl group, a nivoquin group, etc. can be used arbitrarily.

Also, known compounds that are commonly used as photopolymerization initiators for polymerizing photosensitive resins may be used, such as benzoin alkyl ether, benzophenone, Michler ketones, thioxanthones, acetophenones, etc., and sensitizing photopolymerization initiators. For example, anthraquinone, 5-nitrofluorene, etc. are used as photosensitizers that have the effect of broadening the wavelength range, and stabilizers such as radical polymerization inhibitors, modifiers, and relatively low molecular weight oligomers are used to improve storage stability. Alternatively, a diluent such as a monomer may be included at the same time. At the same time, in order to improve the solubility of the reactants to be included, high-boiling oily heating media such as alkylnaphthalenes, etc.
Alkylbiphenyls, alkylidene biphenyls, esters, and the like are sometimes used as solubilizing agents, but it is inappropriate to use them in large amounts because they adversely affect the degree of curing.

The chromogen used in the present invention is 3,3-bis(P
-dimethylaminophenyl)-6-dimethylaminophthalide, 3,3-bis(P-dimethylaminophenyl)phthalide, 3-(P-dimethylaminophenyl)-3-
Triarylmethane compounds such as (1,2-dimethylindol-3-yl)phthalide, diphenylmethane compounds such as 4,4-bisdimethylaminobenzhydrin benzyl ether, 3-dimethylamino-7-medoxyflu Xanthine compounds such as oran, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-dibenzylaminofluorane, thiazine compounds such as benzoylleucomethylene blue, 3-methyl-spiro-dinaphthopyran, 3-propyl-spiro Examples include spiro compounds such as dibenzobilane.

The photosensitive toner having a microcapsule shape used in the present invention can be produced by a method known in the art. For example, the phase separation method from an aqueous solution as shown in U.S. Patent Nos. 2,800,457 and 2,800,458, etc.
The interfacial polymerization method as shown in Japanese Patent Publication No. 36-9168, the 1n-situ method by polymerization of monomers as shown in Japanese Patent Application Laid-Open No. 51-9079, etc., British Patent No. 952807 , the melting dispersion cooling method shown in the equivalent specification No. 965074, etc., U.S. Patent No. 3111407
Examples include, but are not limited to, the spray drying method shown in British Patent No. 930,422 and the like. In addition, as wall film forming materials, gelatin, gum arabic starch, sodium alginate, nityl cellulose, carboxynityl cellulose, polyvinyl alcohol, polyethylene, polyamide, polyester, polyuretown, polyethyleneimine, etc. are used, but they do not allow sufficient light to pass through. Such materials are more preferable. Color developing substances include acid clay, activated clay, kaolin, zeolite,
Inorganic acidic substances such as bentonite, P-cresol, P-
Octylphenol, P-cyclohexylphenol,
Substituted phenol compounds such as P-phenylphenol, α-naphthylphenol, cumylphenol, and P-chlorophenol; phenolic resin compounds such as phenol-formalin condensates and substituted phenol-formalin condensates; and their use in zinc, nickel, etc. Metal salt-modified phenolic resin compounds modified with polyvalent metals, P-butylbenzoic acid, P-hydroxybenzoic acid, 2,5-dihydroxybenzoic acid, salicylic acid, 5-tert-butylsalicylic acid, 3゜5-di-tert -butylsalicylic acid, 3,5
- Aromatic carboxylic acid compounds such as di(α-methylbenzyl)salicylic acid, metal salts of aromatic carboxylic acid compounds made of metal salts of these compounds with polyvalent metals such as zinc and nickel, or aromatic carboxylic acid compounds and a mixture of polyvalent metal compounds such as zinc acetate and zinc propionate.

As a method for attaching and fixing the color developer substance 500 to the surface of the microcapsules 400, (1) By mixing the color developer substance 500 and the microcapsules 400 and stirring using a mixer blender or the like, the color developer substance 500 is attached to the surface of the microcapsules 400. A color developing substance 500 is fixed.

(2) By spray-drying a dispersion in which microcapsules 400 are dispersed in a solution in which color developer material 500 is dispersed or dissolved (a small amount of binder is added as necessary), color developer material is applied to the surface of microcapsules 400. Fix 500.

However, the method is not limited to these methods. Further, the fixed shape of the color developing substance 500 may be such that it covers the surface of the microcapsules 400 in a layered manner as shown in FIG.

Next, an image forming apparatus using the photosensitive toner of the present invention will be described.

FIG. 3 is a sectional view schematically showing an image forming apparatus using the photosensitive toner of the present invention.

The internal structure of the image forming apparatus 1 is roughly divided into a document table drive system that drives the document table 22 to expose the document 21, and a document table drive system that drives the document table 22 to expose the document 21.
a first developing system for developing an electrostatic latent image on the photosensitive drum 41 with a photosensitive toner 42; and an arbitrary recording medium 5.
1, a second developing system that applies pressure to the photosensitive toner 42 and develops and records it on an arbitrary recording medium 51, and a fixing system that fixes the developed and recorded arbitrary recording medium 51.

A more detailed structure will be explained below with reference to FIG.

The document table drive system includes a document table 22, a drive wire 23 fixed to the document table. It consists of a drive pulley 24 and a drive motor 25.

The exposure system includes a light source 31 for irradiating light onto the original 22, a slit 32 for performing slit exposure, and a lens 33 for forming and exposing a reflected image of the original 22 onto the photoreceptor drum 41.

The first development system includes a photoreceptor drum 41 that forms an electrostatic latent image by exposure, and a photosensitive toner developer 44 that develops the electrostatic latent image on the photoreceptor drum 41 along the rotational direction of the photoreceptor drum 41. , a cleaning unit 47 having a cleaning blade 46 for cleaning the photoreceptor 41, a static elimination lamp 48, a charging corotron 49, and a cleaning unit 47 disposed inside the photoreceptor drum 41 opposite to the position where the original reflected image is formed on the photoreceptor drum 41. It consists of an exposure heater 40.

The transport system includes a cassette 52 that supplies an arbitrary recording medium 51.
, and a conveyance roller 53 that conveys an arbitrary recording medium 51.

The second development system includes a pressure roller 61 for pressurizing the exposed photosensitive toner 42 to develop and record it on an arbitrary recording medium 51, and a development heater 62 for heating the pressure roller 61. Here, the photosensitive drum 41 is used as one pressure roller of the pressure mechanism.

The fixing system includes a thermal fixing device 71 and a paper discharge tray 72 for fixing the developed and recorded image on any recording medium 51.

Next, the overall operation of the present image forming apparatus will be explained with reference to FIG.

First, the original 21 is passed through the slit 32 by the light source 31.
light is irradiated on. The reflected image of the document is exposed onto the charged photoreceptor drum 41 by the lens 33 to form an electrostatic latent image. This electrostatic latent image is first developed with photosensitive toner 42 supplied from a photosensitive microcapsule toner developer 44 . The photoreceptor drum 41 rotates in synchronization with the movement of the document platen 22, and after an electrostatic latent image corresponding to 21 sheets of originals is developed on the photoreceptor drum 41, the photoreceptor drum 41 is coated with photosensitive toner 42 on its surface. Return to the starting position while keeping it attached.

At the same time, the document table 22 also returns to the starting position, and the document 21 is again irradiated with light from the light source 31, forming a reflected image of the document.

In the current exposure, a reflected image of the document is formed on the photosensitive toner 42 adhering to the photoreceptor drum 41.

The inner core of the photosensitive toner 42 is heated to 30° C. or higher by the exposure heater 40 and changes its phase to a liquid state. In this state, a latent image is formed depending on the degree of viscosity change of the photosensitive resin in the photosensitive toner 42 corresponding to the amount of exposure.

After development, the photosensitive toner 4 is deposited on any recording medium 51.
The process of developing and transferring the image formed by step 2 begins.

First, in synchronization with the rotation of the photoreceptor drum 41, an arbitrary recording medium 51 is supplied from the cassette 52 via the conveyance roller 53 directly below the photoreceptor drum 41.

Here, in this embodiment, the photosensitive drum 41 is used which can also be used as a pressure roller, and only when the above-mentioned arbitrary recording medium 51 is interposed, it cooperates with the pressure roller 61 to make a photosensitive drum. The structure is such that nip pressure is applied between the body drum 41 and the pressure roller 61.

An arbitrary recording medium 51 is passed between the nip between the photosensitive drum 41 and the pressure roller 61 configured as described above in synchronization with the rotation of the photosensitive drum 41.

When passing between the photosensitive drum 41 and the pressure roller 61, the photosensitive toner 42 is heated by the developing heater 62 via the pressure roller 61, and the photosensitive toner 4 in the unexposed area is heated.
2 is in a liquid state, and since the photosensitive toner 42 in the exposed area is hardened by a photopolymerization reaction and remains in a solid state, the photosensitive toner 42 in the unexposed area on the photoreceptor drum 41 is destroyed by pressure.

Primary color bodies are released from the photosensitive toner 42 in accordance with the degree of exposure, come into contact with a color developing substance, react, develop a color, and are transferred onto an arbitrary recording medium 51 under pressure. After transferring the photosensitive toner 42, the surface of the photosensitive drum 41 is cleaned by a cleaning blade 46 in a cleaning unit 47, neutralized by a static elimination lamp 48, and uniformly re-charged by a charging corotron 49, returning to the initial state. .

On the other hand, the image transferred onto the arbitrary recording medium 51 is fixed on the arbitrary recording medium 51 by the thermal fixing device 71, and the arbitrary recording medium 51 is transferred to the paper output tray 7 by the conveyance roller 53.
2, and the entire recording process is completed.

In the above embodiment, an example was shown in which the photoreceptor drum 41 was of a type that could also be used as a pressure roller. The attached exposed photosensitive toner 42 is transferred all at once onto an arbitrary recording medium 51 using a transfer corotron, and after pressure development is performed by the pressure development mechanism, it is fixed.

It may also be a mechanism for ejecting paper.

[Experiment example] A mixture of 9 parts of trisph-methacryloxyethyl isocyanurate, 7 parts of crystal violet lactone, and 3 parts of diethylthioxanthone in 20 parts of methylene chloride was mixed with 200 parts of water in which a cationic or nonionic surfactant and 1 part of gelatin were dissolved. The mixture was emulsified and dispersed using a homomixer under heating at 60° C. to form an oil-in-water emulsion with oil droplets of 2 to 6 μm.

Stirring was continued at 60° C. for 30 minutes, and methylene chloride was distilled off to give an average particle size of 10 μm. To this was added 20 parts of water in which 1 part of gum arabic was dissolved, and while slowly cooling, aqueous ammonia was added to the mixture to bring the pH to 11 or more, thereby completing the encapsulation.

Thereafter, the microcapsules obtained by spray-drying the capsule dispersion in a spray dryer and a fine color developer were mixed in a mixer to obtain a photosensitive toner.

When the photosensitive toner thus obtained was loaded into the image forming apparatus and an actual copying operation was performed, a clear image was obtained on plain paper.

In this embodiment, the case where one type of photosensitive toner is used is described, but yellow and magenta are sensitive to three independent wavelengths of light.

It goes without saying that a color image can be obtained by using three types of photosensitive toners that develop cyan colors.

[Effects of the Invention] As is clear from the detailed description above, according to the present invention, an image can be formed on any recording medium, and only one type of developing device is required, so that the device can be made smaller; Cost reduction can be achieved.

[Brief explanation of drawings]

1 to 3 show embodiments embodying the present invention. FIG. 1 is a sectional view showing an enlarged cross section of an embodiment of photosensitive toner, and FIG. FIG. 3 is a sectional view schematically showing an image forming apparatus using photosensitive toner. In the figure, 42,100 is a photosensitive toner, 400 is a microcapsule, and 500 is a color developer.

Claims (1)

[Claims] 1. A photosensitive toner comprising microcapsules containing a photosensitive resin and a chromogen, and a color developing substance that causes the chromogen supported on the surface of the microcapsule to develop color.