JPH05134444A - Microcapsule toner - Google Patents

Abstract

PURPOSE:To give such functions as to improve strength and electrifying property of a microcapsule toner by constituting the outer shell of the toner of two or more layers. CONSTITUTION:A microcapsule toner 1 consists of the outer shell part and inner liquid part. The outer shell part consists of two layers that the thick outer layer part 2 to improve the strength and an inner thin part 3. The liquid component contains a photosensitive resin and a picture image forming material such as dyestuff. The capsule has two layers to improve the strength, however, more layers may be formed to give the functions to the toner 1. A film to improve electrifying property may be provided. This microcapsule toner 1 can be produced by well-known methods for microcapsules or repeating a method by changing materials.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microcapsule toner used in an image forming apparatus or the like.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No. 3-80258 discloses a toner comprising a microcapsule which contains a pigment precursor such as a dye precursor and changes mechanical strength in response to light. Further, an image forming apparatus for forming an image on an image receiving paper by a developing method using the microcapsule toner and exposing the toner to light, and then destroying only the weak toner by pressure is disclosed in JP-A-3-80258. It is disclosed in Japanese Patent Laid-Open No. 3-92856. In this image forming apparatus, a toner application mechanism that charges the toner, holds it on a carrier, and attaches it to the carrier by electrostatic force, a unit that exposes microcapsule toner according to image information, and flows out the pigment body. It has a means for destroying microcapsules.

[0003]

However, the microcapsule toner used in these image forming apparatuses is produced in one step by a known technique such as a chemical method, a physicochemical method, or a physical method. Was there. In such a one-step preparation, the strength of the microcapsule toner is often insufficient, which causes a problem of difficulty in handling.

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 manufacturing method in which functionality such as strength is improved and which can be easily encapsulated.

[0005]

To achieve this object, the microcapsule toner of the present invention is characterized in that the outer coat thereof is composed of two or more layers of substances.

[0006]

In the microcapsule toner of the present invention having the above structure, the microcapsule toner can be provided with functionality such as strength improvement or chargeability improvement.

[0007]

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 a microcapsule toner to which the present invention is applied. Microcapsule toner 1
Is composed of an outer shell portion and a liquid component inside thereof. The outer shell portion is divided into two layers, and is composed of a thick film outer shell portion 2 for improving strength on the outer side and a thin film outer shell portion 3 on the inner side. The outer shell is not limited to two layers and may be any number of layers as long as it is composed of a plurality of layers. The outer diameter of the microcapsule toner 1 is preferably several μm to several tens of μm, but is not limited to this.

The thin film outer shell 3 of the microcapsule toner 1 is preferably formed by an interfacial polymerization method or the like because it is desirable that a film is easily formed in a short time. Further, it is desirable that the outer thick film outer shell portion 2 is formed by an in situ method, a coacervation method or the like, since it is desirable that the film is thick and has strength. However, the manufacturing method is not limited to these.

The liquid component contains at least a photosensitive resin 5 and an image forming material 6 such as a dye.

As the image forming material 6, it is possible to use a dye precursor or the like which changes color by reacting with a dye, a pigment, a color developer or the like. 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.

The photosensitive resin 5 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 polymerization of the resin, and for example, benzophenone, benzoyl alkyl ethers such as benzoyl isopropyl ether, Michler's ketone, metal arene compound, 2,4-
Diethyl thioxanthone 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.

Next, a method for producing the microcapsule toner 1 will be described with reference to FIG.

The microcapsule toner 1 can be produced, for example, by combining a plurality of well-known microcapsule production methods or by performing the same production method a plurality of times with different substances. Infinite combinations of interfacial polymerization and in situ methods, multiple in situ methods, interfacial polymerization and coacervation methods, coacervation and spray drying methods, etc. There is no limitation to the combination. If the outer shell portion is made to have three or more layers, the number of combinations will increase, but any combination may be used. In addition, when the outer shell is formed, the film can be formed by the surface modification technique or the like without using the microencapsulation technique.

In this embodiment, the interfacial polymerization method and in
A combination of in situ methods was used.

(1) First, a liquid component as an inclusion, here, 10 g of a polymerizable substance 5 and 0.2 g of an image forming material 6 are mixed, and 0.5 g of terephthaloyl dichloride necessary for interfacial polymerization is mixed therein. Dissolve. The polymerizable substance 5 and the image forming material 6 are preferably lipophilic.

(2) The above liquid components are added to 100 ml of a 1% protective colloid aqueous solution and emulsified.

(3) 6 g of a 5% aqueous solution of hexamethylenediamine and 4 g of a 10% aqueous solution of sodium hydroxide are added to the above emulsified solution. Immediately after the two solutions are mixed, an interfacial polymerization reaction occurs at the interface between the oil phase and the water phase, and the thin film outer shell 3 is formed.

(4) If the thin film shell 3 is generated, P
Adjust to H4-5.

(5) Melt 1.5 in advance in PH9 solution
g and 4 ml of formalin dissolved therein are added.
As the temperature is raised, the polymerization reaction proceeds, and the melamine-formaldehyde resin is gradually formed on the surface of the thin film outer shell 3. When stirring is carried out at about 80 ° C. for 3 hours, most of the reaction is completed and the thick film outer shell 2 is formed.

(6) PH7, cooled and dried. At this time, filtration may be performed if necessary.

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.

For example, in this embodiment, the double capsule is used to improve the strength, but any capsule may be used for the purpose of imparting functionality to the microcapsule toner, and multiple capsules may be used to improve the charging property. .. Specifically, the first wall is prepared in advance by a method such as an interfacial polymerization method in which it is relatively easy to form a film, and nylon, melamine-formaldehyde resin, or the like is used in order to make the first wall positively charged. For charging, polyethylene, acrylic or the like may be attached or encapsulated.

[0025]

As is clear from the above description,
In the microcapsule toner of the present invention, the outer skin is 2
Since it is composed of more than one layer, it is possible to easily impart functionality such as strength improvement or chargeability improvement.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating production of microcapsule toner.

[Explanation of symbols]

 1 Microcapsule 2 Thick film outer shell 3 Thin film outer shell 5 Polymerizable substance 6 Image forming material

Claims (1)

[Claims] 1. A microcapsule toner containing at least an image forming material such as a dye, wherein the outer coat is composed of two or more layers of substances.