JPS58173754A - Toner - Google Patents

Abstract

PURPOSE:To obtain a superior toner hving perfectly spherical uniform particles and even electric properties, by polymerizing a liq. mixture of a polymerizable monomer and a colorant dispersed into fine particles into a dispersion medium through application of electrostatic force. CONSTITUTION:A polymn. initiator is dissolved into a polymerizable monomer, such as styrene, and a colorant, such as carbon black, is mixed with it. The obtained liquid mixture is divided into very fine droplets by using an atmizer 1 or the like, and applying voltage between the atomizer 1 An aq. PVA soln. is supplied in the wall 3 from a dispersion medium feed vessel 6, the droplets 4 are collected, and fed through a wall bottom 5 to a polymn. reactor, heated and stirred to complete polymn. A toner perfectly spherical, and uniform in size, good in fluidity, and especially uniform in electrostatic characteristics can be obtd. at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner used in electrophotography, electrostatic printing, magnetic recording, and the like.

Toners for such purposes are dyes that form and describe images, such as those described in U.S. Pat. No. 2,297,491* in electrophotography; A number of methods are known, generally utilizing a photoconductive material to form an electrical latent image on a photoreceptor by various means, and then developing the latent image with a toner.
After the toner image is transferred to a transfer member such as paper as necessary, it is fixed by heating, pressure, solvent vapor, etc. to obtain a copy. Various methods have been proposed in the past for developing and fixing toner, and each method is indispensable! It is used accordingly.

Conventionally, toners used for these purposes include Jiuhui powder, which is prepared by dispersing coloring materials such as dyes and pigments in a binding material such as natural or synthetic resin. Generally, the binding material and coloring material are mixed, melted and heated at high temperature, and after cooling, jet
Fine particles are obtained by crushing with a crushing device that uses airflow.

The primary purpose of the toner used for the above purpose is to obtain a uniform, stable uniform product, but the toner obtained by the conventionally known method described above has to be mixed, cooled, and pulverized. Due to the nature of the process, it is extremely difficult and difficult to obtain particles that are uniform in nature, i.e., toners are generally used with particle diameters ranging from a few microns to around 30 microns, but are completely free of coloring and binding materials. It was extremely difficult to mix the mixture evenly, resulting in non-uniform particles. For this reason, methods have been used to improve dispersion into the binding material by using a container with a high shearing force and by processing the coloring material, but these methods are not always sufficient. When heated and molten, the particles remain finely dispersed, but when cooled, phase separation occurs, resulting in non-uniform particles when pulverized. Furthermore, if the product is cooled in a uniformly dispersed state and then crushed in the next crushing process, the crushing force cannot be obtained uniformly and in a constant shape. However, when such toner particles are actually used, it is necessary to take into account the non-uniformity of the particles, i.e., the coloring power, the hiding power, etc. optical properties such as force, electrostatic charge,
Due to non-uniformity in electrical properties such as conductivity, and thermal properties such as melting point and heat of fusion, it is not possible to obtain uniform development characteristics, transfer characteristics, and fixing characteristics, resulting in uneven and unclear images. It was unavoidable that the situation would be unstable. ★9. Conventionally, the non-uniform shape of toner includes mechanical non-uniformity in strength, and this means that when toner is actually used, rounded toner that changes shape is 9, resulting in changes in the durability properties.

Conventionally, rounding to solve such problems involves adding a rounding substance during mixing to make the whole particle uniform, surface treatment to make the shape and characteristics of the round particles uniform, and classification to make the particle size uniform. Although it is known that treatments and the like are carried out, it is difficult to obtain fully satisfactory characteristics.

In addition, as a means to solve these problems,
As shown in Japanese Patent Application No. 1-14895, a method is also known in which fine particles of a mixture of K, a monomer, and a colorant are prepared and polymerized in this state to directly obtain a toner. However, there are several problems that arise with this method, namely, there are insufficient methods to completely prevent the deterioration of toner properties caused by incompletely polymerized products or residual stabilizers, emulsifiers, etc.; The K used to create this was not realistic.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and provide a toner. That is, the objective is to obtain toner particles in which the colorant and the binding material are uniformly dispersed, and which have a uniform shape and uniform particle size.

An object of the present invention is to provide toner particles that are uniform in shape and completely spherical.

It is an object of the present invention, in particular, to obtain electrostatically uniform particles.

First, it is an object of the present invention to provide a method for obtaining an inexpensive toner with fewer steps.

An object of the present invention is to provide a toner that can provide stable and uniform images.

A further object of the present invention is to provide a novel method for producing toner.

The present invention, which achieves the above object, involves preparing a liquid material containing a polymerizable monomer and a coloring material in advance, making it into fine particles, dispersing it in a dispersion medium, and then polymerizing the monomer. This is a toner characterized by nine particles separated from a dispersion medium.

In order to achieve the present invention, we must first use polymerizable materials! - preparing a liquid containing coloring material; For this purpose, various conventionally known mixing methods and devices can be used. That is,
These include various milling machines, ball mills, attritors, etc.

This liquid is then atomized in liquid form. Atomization is -
This is carried out using a liquid material supply means such as a liquid fluid nozzle, a gas-liquid fluid nozzle, or a rotating disc atomizer. That is,
Supply liquid to the above equipment (5d/win~1000d/
Then, the particles are atomized using high-pressure air force, rotational dispersion force, etc. Ultrasound during this time,
By applying an external force such as an electrostatic force, more efficient and uniform droplets can be formed. In particular, electrostatic force acts extremely effectively for the purpose of efficient atomization and uniform particle size. The electrostatic force is 2 KV to 200 (more preferably 60 KV) to the opposing electrode.
It is best to apply ~120[Y)O DC voltage.

Next, the droplets are formed and the fine particles are dispersed in a dispersion medium such as water.Then, the monomer in the paper-forming particles is polymerized by an operation such as heating. , separated by a method such as filtration, dried, washed, and extruded as fine toner particles.

The 11th outline of the process example of atomizing a liquid substance! Shown in I.

1 is a liquid supply means such as a liquid fluid nozzle, an air flow two-fluid nozzle, and a rotating disk atomizer. 2 is a power source used when applying electrostatic force, and a liquid supply means 1;
Electrostatic force is applied to the interface between the opposing walls 5. The droplets 4 supplied from the liquid material supply means 1 are atomized into spheres, collected in the dispersion medium supplied from the dispersion medium supply tank 6 to the inside of the opposing wall 3, and are all collected from the collection port 5.
- Typical fishing rods for achieving the present invention include styrenic monomers such as styrene, p-chlorostyrene, and vinylnaphthalene; vinyl acetate,
Vinyl propionate, vinyl benzoate, vinyl butyrate, etc. - Esters of methylene aliphatic carboxyl acids (
For example, methyl acrylate, ethyl acrylate, n
-butyl acrylate, imbutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl alpha-lyaloacrylate, methyl methacrylate, ethyl methacrylate and butyl methacrylate)
; violet-vinyl compounds, violet-vinyl vinyl compounds, violet-vinylcarbazole, violet-vinyl indole, and the like. These monomers may be used singly or in combination.

Any suitable coloring material may be used in the present invention. The colorant must be able to be dispersed in the monomer, be insoluble in the dispersion medium in the subsequent co-polymerization step, and have sufficient coloring power when used as a toner.

Examples of such materials include 7-thalocyanine pigments such as copper phthalocyanine, anthraquinone pigments, carbon black, various dyes, and magnetic pigments such as magnetite. The above pigments may be subjected to surface treatment, processing, etc. in order to increase their dispersibility and stability.

Any initiator that is compatible with the particular monomer used may be used in the present invention. For example, peroxide-based initiators and azo-based initiators, particularly suitable for the present invention are azobis(2-methylprobionide dal) and ruff-yl peroxinide. The initiator may be added to the monomer at the time of mixing the pigment and the pigment, or after the colorant and the monomer are mixed. The initiator is approximately 2% of the monomer
~10-t% is suitable, and 2-set% is particularly good.

As the dispersion medium, various solvents can be used alone or in combination, and water is most commonly used2. If necessary, stabilizers and dispersants such as bobbinyl alcohol, ethylene glycol, and glycerin can be used. Used in addition.

The toner obtained by the present invention has a completely uniform shape, that is, a true spherical shape, and its particle size is surprisingly uniform compared to conventional toners. It has excellent rolling fluidity, is easy to handle, has good stability, and can produce good images without contaminating the developing device or causing unnecessary adhesion to the surface of the photoreceptor.

The toner produced by the method of the present invention can be applied for development by any method known in the art.

For example, the magnetic brush development method described in U.S. Pat. No. 2,874,065, the cascade development method described in U.S. Pat. No. 2,618,552, and U.S. Pat.
Paradark 2 cloud method and fur brush development method described in No. 221776 Mei#A+, and also his 909
．． A method using a conductive magnetic toner described in JP-A No. 55-51156, a method using a round high resistance magnetic toner described in JP-A-55-51156, and JP-A-54-42141.

The methods described in JP 54-42142, JP 54-45027, etc. are used.

In addition, to fix the toner, heat energy is used to fix the toner, such as the nine heat chamber method, the heat roll method, and the U.S. Patent No. 4 method.
24*626).

The present invention will be explained in more detail below with reference to specific embodiments.

<Example 1> 100j of styrene monomer K''5II of lafroyl peroxinide was added and warmed to dissolve.

After adding 71 carbon platters to this temperature,
11 and 9. Next, this mixed liquid is supplied to a) washer, which has a rotating disk with one straight pole 121, and the disk is rotated 5 times.
At the same time as it rotates in the QOOOrp town, an electrostatic voltage of 90V is applied to it to make it into fine particles.9.

A counter electrode is provided adjacent to the disk and includes 1.
The liquid flow surface of a 25% polyvinyl alcohol aqueous solution was formed and the formed droplets were collected.Then, the dispersion liquid was placed in a 1000+ liter round bottom flask in a reaction vessel equipped with a stirrer, and about 70 tl was collected. 60～＠Q
Polymerize for 6 hours with stirring at rpm. The particles were washed, separated, and dried from the particle-containing dispersion. The resulting powder was a highly fluid, smooth powder with each particle having a perfect spherical shape and an average particle size of 10.5μ.
It can be confirmed that 90% exists at the 2μ ratio.

5 parts by weight of the prepared nine toner and 80 parts by weight of iWK iron powder carrier were added as a developer to develop the surface of the photoconductive substance carrier having a positive electrostatic latent image, transferred to tatami paper, and passed through a heat chamber type fixing machine. When I looked at it, it turned out to be an extremely clear image, and it was completely fixed.

<Example 2> Same as Example 1 except that a mixture of 65 parts of styrene and 35 s of n-butyl methacrylate was used as a 7-mer, 2 s of azoisobutyronitrile was incorporated as an initiator, and ethyl cellulose was used as a stabilizer. Natsu9. Good results similar to those of Example 1 were obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram schematically showing an example of a process for atomizing a liquid material. 1...Liquid supply means 2...Power source 5...Opposing wall 4...Droplets 5...Collection port 6...Dispersion medium supply tank Ichihara, Hiroto Canon Co., Ltd.

Claims (1)

[Claims] A toner is obtained by pulverizing a liquid material containing a polymerizable monomer and a coloring material, dispersing it in a dispersion medium, polymerizing the powder, and then removing the dispersion medium.