JPH04141666A - Color developable toner - Google Patents

Abstract

PURPOSE:To improve fixability by pressurization to arbitrary recording media by externally adding superfine particles of <=1mum to a core material having pressure fixing performance, then forming shells coated like films on the surface of the core material by a mechanical or thermal effect. CONSTITUTION:The core material contg. a color developer which is a dye receptor is formed together with a pressure fixing component and the superfine particles of <=1mum are mixed with the core material of the color developer toner by a mixer and are thereby stuck to the circumference of this core material. Thermal or mechanical energy is applied to the color developer toner mixed with the superfine particles, by which the films produced by melting of the superfine particles are formed on the core material of the color developer toner. The fixability by pressurization to the arbitrary recording media which are the recording media to be fixed is improved in this way.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a developer that can be used in an electrostatic transfer method, and further relates to a developer that can be used in an electrostatic transfer method, and furthermore, a developer that can be used to develop a color by reacting with a dye or a dye precursor. The present invention relates to a developer toner that can be used in an electrostatic transfer method.

[Prior art] Conventionally, color developers have been dispersed as ultrafine particles in an aqueous solvent, and after adjusting binders, additives, etc., they are applied to paper, and used as special paper called developer sheets. It existed. This image forming technique using a color developer sheet is described in Japanese Patent Laid-Open No. 58-88739, Japanese Patent Laid-Open No. 59-30537, Japanese Patent Laid-Open No. 59-137944, and the like.

Image forming technology is the process by which two or more components isolated from each other are released from their isolation by physical external forces such as pressure or temperature changes, and react with each other, resulting in optical changes and light absorption regions. , or all functions that cause changes in absorption intensity and are recorded in response to external forces. For example, by overlapping a photosensitive pressure-sensitive recording medium, in which microcapsules whose mechanical breaking strength changes with light irradiation is supported on an arbitrary medium, and a color developer sheet, and performing pressure development, the mechanical breaking strength can be improved. A substance that selectively clears different microcapsules and reacts with colorless or slightly colored dyes or dye precursors contained in the microcapsules to develop a color, i.e., dye receptor or color developer. This is an image forming system that reacts with a developer to form a developed image on a developer sheet. As a means of forming an image on any recording medium using these conventional image forming techniques, any recording medium can be formed by making powdered color developer and electrostatically flying it onto any recording medium. There is a technique in which an image is formed by forming a color developer sheet as a base material, superimposing a microcapsule sheet on the color developer sheet, and performing pressure development. In addition, this technology includes not only electrostatic coating technology for developer toner, but also developer toner adhered to any recording medium.
Since the developer toner directly contacts the microcapsule sheet and is pressurized by a pressure developing device, the developer toner must also have the ability to be fixed under pressure on any recording medium.

[Problems to be Solved by the Invention] However, when the developer is a powder, there is a drawback that the developer toner becomes sticky due to the inherent characteristics of the developer. This is because the color developer itself is sticky, and in the conventional toner manufacturing method by crushing, it is difficult to adhere to the device, the pressure fixing performance and fluidity performance are insufficient, and the toner is repeatedly produced. Developing performance and fixing performance are unstable for use,
It caused adhesion to the toner carrier and toner case, and agglomerated and caked during storage, resulting in poor storage stability.

A color developer toner containing a soft substance as a color developer has good pressure fixing properties, but has the above-mentioned problems. When a hard resin is mixed with a color developer, it is easy to form a toner and has excellent charging properties and storage stability, but the pressure fixing properties are extremely poor. Color developer toner containing hard resin is often harder than the recording medium to which it is fixed, and when pressurized, it is simply pressed against the recording medium and does not cause any damage to the recording medium. Does not get entangled in media pores or fibers.

Furthermore, simply attaching fine particles around the core material of the color developer toner lacks charging stability and fluidity.

The present invention has been made to solve the above-mentioned problems, and has good fixing properties by pressure on any recording medium as a recording medium, and has good charging properties and charging stability as a toner. The present invention provides a color developer toner.

[Means for Solving the Problems] In order to achieve this object, the developer toner of the present invention has the following features:
This is because after ultrafine particles of 1 μm or less are externally added to a core material having pressure fixing performance, an outer shell coated in a film-like manner is formed on the surface of the core material by mechanical or thermal effects.

[Function] According to the present invention having the above configuration, it contains at least one kind of color developer which is a dye receptor, forms a core material together with a pressure fixing component, and forms a submicron-order layer around this core material. The ultrafine particles are mixed with the core material of the color developer toner using a mixer such as a Henschel mixer, and are allowed to adhere. By applying thermal or mechanical energy to the developer toner mixed with ultrafine particles, a film is formed by melting the ultrafine particles to the core material of the developer toner.

[Example] Hereinafter, the constituent elements of the present invention will be explained.

The microcapsules used in the image forming system in which the color developer composition of the pressure-sensitive recording medium of the present invention is used are characterized by the fact that the amount of curing of the encapsulated photocurable resin changes depending on the amount of light irradiation, and mechanical destruction occurs. The strength changes depending on the amount of curing of the included photocurable resin. The microcapsules contain not only a photocurable resin but also a dye and a dye precursor, which are coloring media that develop color upon reaction with a developer, which is a dye receptor. Typical examples thereof include crystal violet lactone and benzoylleucomethylene, but many other homologues are known and have been put into practical use.

On the other hand, when the dye precursor contained in the microcapsules is crushed by pressure and discharged from the microcapsules, acid clay, bentonite, kaolin, etc. natural clay minerals such as night, attapulgide; organic acids and their esters such as tannic acid, gallic acid, propyl gallic acid ester, etc.; phenolic resins, maleic acid resins, phenol-acetylene resins, carvone having at least one hydroxy group Acidic polymers such as condensation products of acid and formaldehyde; zinc salicylate, tin salicylate, zinc 2-hydroxynaphtonate, 3,5-di-t-
Examples include metal salts of aromatic carboxylic acids such as zinc butylsalicylate and zinc 3.5-α-methylbenzylsalicylate; metal salt-modified phenolic resin compounds modified with polyvalent metals such as zinc and nickel, and mixtures thereof. It will be done.

When trying to powderize a mixture of these color developers and apply it electrostatically to any medium, the powder characteristics of the color developer affect the ability to reliably fix the mixture to the recording medium, so the dye precursor It imparts pressure fixing performance to the color developer. A fixing agent such as a wax and an adhesive is mixed as a substance that improves fixability and adhesion to any medium and also has good adhesion to a color developer.

For example, ethylene-vinyl acetate copolymer, polyvinyl ether, vinyl chloride-vinyl acetate copolymer, polyvinyl chloride, polyacrylic acid ester, ethylene-ethyl acrylate copolymer, polyvinyl acetate, which are known as adhesives, Examples include polyvinyl butyral and polyvinyl acetate. In addition, waxes include carnauba wax, candelilla wax, rice wax, lanolin wax, jojoba wax, Japan wax, beeswax wax, paraffin wax, microcrystalline wax, montan acid ester wax, halogenated paraffin wax, castor wax, Examples include Schrag wax, Sasol wax, amide wax, Osikelite, and polyolefins such as polyethylene and polypropylene.

Create particles that uniformly contain the developer component and fixing component used in the core material. 10 to 500 to this color developer toner core material.
By externally adding nano-sized ultrafine particles using a mixer such as a Henschel mixer, the agglomeration caused by the adhesion of the developer between the core materials on the surface of the developer toner core material can be prevented by the presence of ultrafine particles between each particle. It can be prevented by Examples of ultrafine particles include acrylic resin, fluorine resin, silicone resin,
There are nylon, polystyrene, etc.

Simply having ultrafine particles around the core substance of the developer toner can prevent the developer from agglomerating together, but it does not increase the fluidity; Needs to be coated. By doing so, it is possible to eliminate adhesion and caking within the toner case that are thought to be caused by unevenness of the developer toner. When coating the surface of developer toner with ultrafine particles using mechanical or thermal energy, care must be taken to prevent the developer toner from fusing inside the manufacturing equipment, as it has a pressure fixing property. It is necessary to set the rotation speed or hot air temperature.

When a color developer toner whose surface is coated with ultrafine thermoplastic particles is filled into an electrostatic coating device and electrostatically transferred onto plain paper, which is the recording medium, the toner has good fluidity in the toner case and is transferred onto the plain paper. Uniform coating was possible. Also,
The surface of the image formed on the plain paper was able to be formed without stickiness.

[Experiment example] p-phenylphenol 100 parts p-t-butylphenol 40 parts polyethylene wax
20 parts ethylene-vinyl acetate copolymer 10
In the components of the above color developer composition, p-phenylphenol and pt-butylphenol are resin lumps when they are raw materials before being mixed, and polyethylene wax and ethylene-vinyl acetate copolymer are powders. Therefore, these are dry crushed and mixed into powder using a Henschel mixer.

Next, the toner is melted and kneaded at 100 C' in a kneader, pulled out from the kneader, and the core substance of the developer toner is cooled and solidified at room temperature. The core substance of the developer toner that is drawn out and formed into a lump is crushed in a coarse crusher and crushed into 1. The particles become 5 mm or less. This is pulverized using an air jet mill. The powder produced by pulverization ranges from extremely fine powder of several micrometers to hundreds of micrometers. Very fine powder and very coarse powder are classified and cut using an air classifier. In this way, a developer toner core material powder having an average particle size of about 10 μm is obtained. When 2 parts by weight of ultrafine acrylic particles of 0°4 μm are added to the core material of the developer toner and mixed in a Henschel mixer, the ultrafine acrylic particles uniformly adhere to the surface of the core material of the developer toner. This is quantitatively sent to a surface modification device, and ultrafine acrylic particles are formed in a film shape on the surface of the core substance of the color developer toner due to mechanical or thermal effects, completing the surface modification. It is also possible to mix a charge control agent with the ultrafine acrylic particles to control the chargeability of the developer toner surface.

[Effects of the Invention] As is clear from the detailed description above, according to the present invention, it was possible to obtain a color developer toner that can perform good flight and transfer using an electrostatic transfer method. Furthermore, it was possible to obtain a color developer toner that does not adhere to the inside of the toner case and does not adhere to the toner carrier or the blade.

In addition, the fixability to the recording medium was not hindered, and the surface of the output image was free from stickiness.

Claims (1)

[Scope of Claims] 1. Consisting of a core material containing a color developer, which is a dye receptor that reacts with a dye or a dye precursor to develop color, and a pressure fixing component, and an outer shell that covers the core material. In developer toner, after ultrafine particles of 1 μm or less are externally added to the core material, mechanical,
Alternatively, a color developer toner is characterized in that an outer shell is formed on the surface of a core material by a thermal effect.