JPS61231562A - Electrophotographic powder - Google Patents

Abstract

PURPOSE:To give releasing performance to the surface of a drum, to prevent attachment of impurities, such as paper powder, to it, and to reduce image-flow phenomenon by externally adding an image-flow preventing lubricant made of wax or a paraffinic material to an electrophotographic powder. CONSTITUTION:The image-flow preventing lubricant made of wax or a paraf finic material, such as carnauba 2 is externally added to an electrophotographic powder, such as the main body 1 of a toner powder, thus permitting paper powder and talc and the like to be collected to the contact face between a cleaner blade and the drum in a copying process, a part of the carnauba 2 present on the blade to pass through it and to attach to the drum surface, accordingly, the paper powder, etc., if ready to attach to the surface of the drum, hardly to attach because of the presence of the releasing agent of the carnauba 2, and even if attached to the surface of the drum, liable to be re leased by the cleaner blade 8. The carnauba 2 is externally added, preferably, in a particle diameter of 5-20mum and in an amt. 0.01-1wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic powder used in electrophotography, and more particularly to an electrophotographic powder for preventing image blurring.

Prior Art In the conventional electrophotographic method, images were obtained by the process shown in FIG.

That is, the sequence is charging → exposure → development → transfer → cleaning.

The problem here is that when the whiteness improver (talc) contained in the paper adheres to the drum 3 side along with paper dust, it is collected at the edge of the cleaner blade 8.

Some of these particles get stuck in the drum 3 or pass through the cleaner blade 8, resulting in talc and paper dust adhering to the surface of the drum 3, and when moisture adheres to these, the surface resistance of the drum 3 is lowered.

There is a drawback that the charge formed on the drum 3-H becomes non-uniform, and even if an image is produced on the drum 3L by the developing device 4, it becomes a streaky image.

This phenomenon becomes especially noticeable in high humidity.

Problems to be Solved by the Invention The present invention is capable of easily removing impurities, that is, talc and paper powder, which lead to the above-mentioned image blurring, by using a cleaner blade.
Another object of the present invention is to provide an electrophotographic powder that reduces adhesion of paper powder to the drum side in a transfer section.

Means and Function for Solving the Problems The present invention provides an electrophotographic powder characterized in that a wax or paraffin-based material is externally added to the electrophotographic powder as a lubricant to prevent image blurring. It consists of

The lubricant used in the present invention is a paraffin or wax based material.

Examples include paraffin, which is used for candle wood, and carnauba, which is used as wax. Wax classification includes solid waxes such as carnauba and cotton, petroleum waxes such as paraffin, microcrystalline wax, petrolatum, and natural montan wax.

Here, carnauba and paraffin are used as examples because they are common substances and are easily available.

The basic toner, which is an electrophotographic powder to which a lubricant is added in the present invention, generally has the following composition.

Toner is made of magnetite, which is a magnetic material, and a binder resin (styrene resin, acrylic resin, polyethylene, polypropylene, etc.) that binds the magnetite. Glossine) is attached to the charge control agent.

In general developing devices, this toner is aggregated, and... Due to the constant rubbing, the tripod of the toner alone increases by 1, causing it to aggregate (clump).

If this continues, the image quality will be uneven even when developed, so silica (SiO) or the like is used as an external additive to prevent agglomeration. Since silica is smaller in particle size than the toner, it gets between the toner particles and improves fluidity.

The amount of silica used is often 0.1 to 0.4% (by weight), and the degree of aggregation of the toner changes depending on the amount of silica, and as a result, the amount of tripo changes.

As an example of the present invention, as shown in FIG. 1, Carnauba 2 is added to the basic toner 1 as an external additive.

As a result, during the copying process, paper dust, talc, etc. adhere to the surface of the drum 3 and are collected on the contact surface of the cleaner blade 8 with the drum 3, and some of the carnauba on the cleaner blade 8 slips through the cleaner blade 8. will adhere to the surface of the drum 3.

In this state, even if paper powder tries to stick to the surface of the drum during copying, it will be difficult to stick because of the releasable property, and even if it sticks, it will be easily removed by the cleaner blade 8.

As for the particle size and amount of carnauba added, based on the experimental dfL results, a particle size of 5 to 20 is best, and if it is smaller than this,
No effect on crying under high humidity.

If the thickness is more than 20 μm, problems such as thin and rough images will occur.

Also, if the amount of external addition is less than 0.01% by weight, there is no effect, and if
(If the amount exceeds 0.01% to 1%, the image becomes thin or rough, so a range of 0.01 to 1% is suitable.

Note that this external addition of carnauba may be added in the external addition step in conventional toner production.

Figure W42 shows the relationship between toner particle size and addition amount, and Figure 3 shows a flowchart of toner production.

Even when paraffin was used, results similar to those obtained using carnauba listed in E were obtained.

As described in detail, the use of the lubricant of the present invention has the effect of imparting release properties to the drum surface, preventing impurities such as paper dust from adhering to the drum surface, and reducing image blurring. It is played.

[Brief explanation of drawings]

FIG. 1 illustrates an example of the configuration of the present invention, and FIG.
3 is a flowchart showing the process of adding carnauba externally during the production of conventional toner; FIG.
The figure is a schematic diagram of a conventional copying machine. Code 1 is basic toner, 2 is Carnauno (, 3 is drum,
4 is a developing device, 5 is a transfer device, 6 is an exposure device, 7 is a charger, 8 is a cleaner blade, and 9 is a paper sheet.

Claims (1)

[Claims] (1) An electrophotographic powder characterized in that a wax or paraffin-based material is externally added to the electrophotographic powder as a lubricant to prevent image blurring.