JP2507801B2 - Toner for electrophotography - Google Patents

Description

The present invention relates to an electrophotographic toner used in an electrophotographic apparatus such as an electrostatic transfer copying machine or a laser printer.

[Conventional technology]

An electrophotographic toner (hereinafter referred to as a toner) used in a thermo-compression type electrophotographic apparatus is a binder resin agent that integrates each material constituting the toner and fixes a colorant on a transfer paper. And a colorant for imparting color to the toner, and a charge control agent for imparting chargeability to the toner. Then, these materials are mixed at the same time, melt-kneaded, the obtained kneaded material is crushed, and then classified to be manufactured as a toner particle having a predetermined particle diameter.

However, with the above toner, the surface of the fixing roller of the electrophotographic apparatus and the toner image formed on the fixing sheet come into pressure contact with each other in a heat-melted state, so that a part of the toner image is transferred to the surface of the fixing roller. , On the next fixing sheet,
This has a problem of causing a so-called offset phenomenon of re-transferring.

Therefore, in order to solve the above problems, in the conventional toner granules, as disclosed in JP-A-52-3304, in addition to the above materials, for example, low molecular weight polypropylene or styrene resin is used. And the like release agent is added. The release agent is usually contained in a proportion of 2 to 3% by weight with respect to 100% by weight of the toner particles.

As a result, the conventional toner can prevent a decrease in maintenance stability such as occurrence of offset due to a decrease in the content of the release agent and sticking of the toner particles to each other due to an increase in the content of the release agent. Good fixing on the transfer paper is possible.

[Problems to be Solved by the Invention]

However, the above-mentioned conventional toner has a problem that when the copying is repeated 20,000 to 30,000 times, the developing property and the transfer property are deteriorated, resulting in missing characters and image density.

This problem is caused by the above-mentioned toner filming on the photoconductor or the transfer intermediate by the cleaning blade when a large number of copies are piled up. In the present situation, when the toner is filmed on the photoconductor or the transfer intermediate, by replacing the photoconductor or the transfer intermediate with a new one, it is possible to solve the above-mentioned problems such as missing characters and a decrease in image density. There is.

Therefore, in the present invention, the transferability of the toner is improved, filming of the toner to the photosensitive member or the transfer intermediate that occurs when a large number of copies are piled up is prevented, and moreover, a large number of copies are made from the initial stage of copying. The purpose is to stabilize the developability and image quality.

[Means for solving the problem]

In order to solve the above-mentioned problems, the electrophotographic toner according to the present invention integrates the respective materials constituting the toner, and a binder resin agent for fixing the colorant onto the transfer paper and a color to the toner. A toner formed on a photoconductor, which is composed of a toner granule having at least a coloring agent for imparting the toner, a charge control agent for imparting the electrostatic property to the toner, and a releasing agent for imparting the releasing property to the toner. In an electrophotographic toner used in an electrophotographic apparatus in which an image is once transferred to a transfer intermediate and then transferred onto a sheet, a releasing agent is contained inside the toner particles in an amount of 100% by weight of a binder resin agent. 1 to 3
The toner particles are internally added in a weight% ratio, and on the surface of the toner particles,
Release agent with a particle size of 0.1-0.2 μm is 100% by weight of toner particles
It is characterized by being externally added at a rate of 0.5 to 1% by weight.

[Work]

According to the above configuration, the release agent added internally and externally prevents the occurrence of offset. Further, since the intermolecular force acting between the externally added release agent and, for example, the photoconductor is reduced, the releasability, transferability and cleaning property of the toner are improved.

This prevents filming on the photoconductor and the transfer intermediate, and further stabilizes the developability from the initial stage of copying to the copying of a large number of sheets, thereby stabilizing the image quality.

Embodiment 1 An embodiment of the present invention is described below with reference to FIG.

The electrophotographic toner according to the present invention (hereinafter referred to as a toner) integrates the respective materials constituting the toner, and imparts a color to the binder resin agent for fixing the colorant onto the transfer paper. And a charge control agent for imparting chargeability to the toner, and a release agent for preventing the toner from adhering to the fixing roller of the electrophotographic apparatus, the photoconductor, and the transfer intermediate. There is.

The release agent is internally added to the inside of the toner particles of the toner and externally added to the surface of the toner particles.

The components of the toner granules excluding the release agent externally added to the surface of the toner granules and the composition ratio thereof are shown in Table 1.

Examples of the binder resin agent include polystyrene, styrene-styrene copolymers such as styrene-butadiene copolymers and styrene-acrylic copolymers shown in Table 1, polyethylene, polyethylene vinyl acetate copolymers, polyethylene vinyl. An ethylene copolymer such as an alcohol copolymer, a phenol resin, an epoxy resin, an allyl phthalate resin, a polyamide resin, a polyester resin, a maleic acid resin or the like can be used.

Further, as the colorant, other than copper phthalocyanine, for example, carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine yellow, methylene blue, DuPont oil red, quinoline yellow, methylene blue chloride,
Malachite Green, Oxalate, Lamp Black,
Rose bergal, and mixtures thereof, are used, these must be included in the toner in an amount sufficient to form a clear visible image.

As the charge control agent, amino compounds, quaternary ammonium compounds and organic dyes, particularly basic dyes and salts thereof are known, and benzyldimethyl-hexadecyl ammonium chloride, decyl-trimethyl ammonium chloride, Table 1 The quaternary ammonium salt, nigrosine base, nigrosine hydrochloride, safranine r, crystal violet and the like shown in 1 can be used. Incidentally, nigrosine base and nigrosine chloride are often used as positive charge control agents.

In addition to polypropylene, the release agent may be animal fats and oils, polyethylene in Examples 2 and 3 described below, and the like.

Next, the full-color copying machine used in this embodiment will be described below with reference to FIG.

As shown in FIG. 1, the full-color copying machine has an exposure optical system 2 that irradiates a document 11 with light and exposes the reflected light to a photoconductor 3, and a sheet-shaped transfer sheet 15 that transfers a toner image. It has a photoconductor 3 and a transfer intermediate 5.

The exposure optical system 2 described above includes a light source lamp 2a, a plurality of reflecting mirrors 2b for guiding the reflected light from the original 11 onto the photoconductor 3 as shown by a chain line, an imaging lens 2c, and three primary colors (red,
And a color separation filter 2d having color filters of green and blue).

Below the exposure optical system 2, a sheet-shaped photoconductor 3 is provided, and the photoconductor 3 is rotationally driven by two rollers 12a and 12b.

On the other hand, a sheet-shaped transfer intermediate 5 is arranged on the side of the second roller 12b of the photoconductor 3. This transfer intermediate 5 is
It is adapted to be rotationally driven by three rollers 14a to 14c.

A method of manufacturing the toner having the above structure will be described below.

Toners composed of the components shown in Table 1 above are usually mixed →
It is manufactured through the steps of kneading → crushing → classification.

That is, first, the above materials were mixed, and the mixture obtained in the mixing step was melted, kneaded, and integrated. After that, the kneaded material integrated in the kneading step is crushed into particles,
By classifying the obtained granules, the average particle size is 10 μm.
Toner Granules A was obtained.

Next, on the surface of the toner granules A obtained by the above method, the average particle diameter is 0.05 μm with respect to 100% by weight of the toner granules A.
0.1% by weight of hydrophobic silica having a charge control function of
0.5% by weight of a low molecular weight polypropylene, which is a release agent having an average particle diameter of 0.1 μm, was externally added.

Then, the toner produced as described above was used in the full-color copying machine shown in FIG. 1 to examine the state of filming and copying.

The operation of the above full-color copying machine will be described below.

In the full-color copying machine, first, the light source lamp 2a irradiates the original 11 with light to perform scanning several times. The reflected light obtained by the above scanning is reflected by the reflecting mirror 2b in the direction of the imaging lens 2c as an optical image. And the above optical image is
Each color component is separated through the imaging lens 2c and the color separation filter 2d.

Each optical image for each color component is imagewise exposed to the uniformly charged photoconductor 3. The latent images for each color component created in order here are developed with the developers of the complementary colors (yellow, magenta, cyan) of the color filters of the color separation filter 2d, respectively, and then visualized, and then transferred to the transfer intermediate 5. Is transcribed to.

In this way, a color toner image is formed by superimposing the toner images of the respective color components on the transfer intermediate 5,
It is transferred to the transfer paper 15.

As a result, it was found that the toner did not film on the photoconductor 3 and the transfer intermediate body 5 incorporated in the copying machine even after copying 20,000 to 30,000 times.

It was also found that the above toner does not cause hollow characters in the characters or uneven image density due to filming, and stable image quality cannot be obtained.

Further, when the above toner is used in a full-color copying machine, the transferability from the photoconductor 3 to the transfer intermediate 5 and from the transfer intermediate 5 to the transfer paper 15 is improved, so that hollow lines, characters, etc. It has been found that the image quality is improved by reducing the noise and making the image density uniform.

From the results of Example 1 and Examples 2 and 3 described later,
The release agent internally added to the toner particles is preferably 1 to 2% by weight with respect to 100% by weight of the binder resin agent, and the release agent externally added to the surface of the toner particles is It has been found that the amount is preferably 0.5 to 1% by weight with respect to 100% by weight of the toner particles, and the particle size of the release agent is preferably 0.1 to 0.2 μm.

Second Embodiment Another embodiment of the present invention will be described below with reference to FIG.

The toner according to the present invention comprises a binder resin agent, a colorant, a charge control agent and a release agent.

The release agent is internally added to the inside of the toner particles of the toner and externally added to the surface of the toner particles.

The components and composition ratios of the toner granules excluding the release agent externally added to the surface of the toner granules are the same as the components and composition ratios of Example 1 shown in Table 1.

 Next, a method for manufacturing the present toner will be described below.

First, toner particles A were obtained in the same manner as in Example 1 using the materials shown in Table 1 above.

Next, on the surface of the toner granules A obtained by the above method, the average particle diameter is 0.05 μm with respect to 100% by weight of the toner granules A.
0.1% by weight of hydrophobic silica and 1% by weight of low molecular weight polyethylene, which is a release agent having an average particle size of 0.2 μm, were externally added.

Then, the toner produced as described above was used in the full-color copying machine shown in FIG. 1 to examine the state of filming and copying.

As a result, it was found that the toner did not film on the photoconductor 3 and the transfer intermediate body 5 incorporated in the copying machine even after copying 20,000 to 30,000 times.

It was also found that the above toner does not cause hollow characters in the characters or uneven image density due to filming, and stable image quality can be obtained.

Further, when the above toner is used in a full-color copying machine, the transferability from the photoconductor 3 to the transfer intermediate 5 and from the transfer intermediate 5 to the transfer paper 15 is improved, so that fine lines and hollow characters may be removed. It has been found that the image quality is improved, such as reduction and uniformization of image density.

Third Embodiment Another embodiment of the present invention will be described below with reference to FIG.

The toner according to the present invention comprises a binder resin agent, a colorant, a charge control agent and a release agent.

The release agent is internally added to the inside of the toner particles of the toner and externally added to the surface of the toner particles.

The components of the toner particles excluding the release agent externally added to the surface of the toner particles and the composition ratio thereof are as shown in Table 2.

Next, a method for manufacturing the present toner will be described below.

First, the toner particles B having an average particle diameter of 11 μm were obtained in the same manner as in Example 1 using the materials shown in Table 2 above.

Next, on the surface of the toner granules B obtained by the above method, the average particle diameter is 0.05 μm with respect to 100% by weight of the toner granules B.
0.1% by weight of the hydrophobic silica and 0.8% by weight of a low molecular weight polyethylene as a release agent having an average particle size of 0.1 μm were externally added.

Then, the toner produced as described above was used in the full-color copying machine shown in FIG. 1 to examine the state of filming and copying.

As a result, it was found that the toner did not film on the photoconductor 3 and the transfer intermediate body 5 incorporated in the copying machine even after copying 20,000 to 30,000 times.

It was also found that the above toner does not cause hollow characters in the characters or uneven image density due to filming, and stable image quality can be obtained.

Further, when the above toner is used in a full-color copying machine, the transferability from the photoconductor 3 to the transfer intermediate 5 and from the transfer intermediate 5 to the transfer paper 15 is improved, so that fine lines and hollow characters may be removed. It has been found that the image quality is improved, such as reduction and uniformization of image density.

〔The invention's effect〕

As described above, the electrophotographic toner according to the present invention has a release agent internally added to the toner particles at a ratio of 1 to 3% by weight based on 100% by weight of the binder resin agent, and the toner. A release agent having a particle diameter of 0.1 to 0.2 μm is externally added to the surface of the granular material at a rate of 0.5 to 1% by weight based on 100% by weight of the toner granular material.

This improves the transferability of the toner, prevents the filming of the toner to the photoconductor and the transfer intermediate that occur when a large number of copies are piled up, and further develops from the initial copy to the multiple copy. The effect is that the image quality and the image quality are stabilized.

[Brief description of drawings]

FIG. 1 illustrates an embodiment of the present invention and is a schematic configuration diagram of a full-color copying machine. 2 is an exposure optical system, 3 is a photoconductor, and 5 is a transfer intermediate.

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-63-61265 (JP, A) JP-A-63-61266 (JP, A) JP-A-63-244053 (JP, A) JP-A-1- 281458 (JP, A) JP-A-1-234858 (JP, A)

Claims (1)

(57) [Claims] 1. A method of integrating respective materials constituting a toner, a binder resin agent for fixing a colorant on a transfer paper, a colorant for imparting color to the toner, and a chargeability for the toner. It is composed of a toner granular material having at least a charge control agent for imparting a releasing property and a releasing agent for imparting releasability to the toner, and after the toner image formed on the photoconductor is once transferred to a transfer intermediate, it is then transferred onto a sheet. In the electrophotographic toner used in the electrophotographic apparatus for transferring, a releasing agent is used as the binder resin agent 100 inside the toner particles.
A release agent having a particle size of 0.1 to 0.2 μm is internally added in an amount of 1 to 3% by weight with respect to 100% by weight of the toner particles, and 0.5 to 1% by weight based on 100% by weight of the toner particles. % Externally added toner for electrophotography.