JPS63314576A - Roll - Google Patents

Abstract

PURPOSE:To properly maintain the roughness of the surface of a roll for a long period and also to prevent the deformation caused by the bending in the roll by constituting a sleeve of a non-magnetic rigidity cylindrical body and an organic high molecular composition thin layer including a fibriform filler formed on the outer peripheral surface of said cylindrical body. CONSTITUTION:The cylindrical sleeve 16 is constituted of the nonmagnetic metal cylindrical sleeve main body 16a and the coating layer 16b made of semiconductive resin, formed on the outer peripheral surface of the main body 16a. And the fibriform fillers 10 whose outer diameters are 5-10mum are countlessly scattered in the coating layer 16b, whose outer peripheral surface is formed into the rough surface whose roughness of the surface is 3-10mum. Even if the surface of the sleeve is weared, the fibriform fillers distributed inside of the sleeve are exposed and the roughness of the surface of the sleeve can be always maintained. And the deformation caused by the bending in the sleeve can be prevented by press-contacting a layer forming blade. Thus, the toner carrier quantity of the developing roll can be properly maintained for a long period and clear copying can be possible for a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a roll used in an electrophotographic copying machine or the like.

[Conventional technology]

There are two types of developing methods used in electrophotographic copying machines: a wet method and a dry method.Recently, the dry method has become mainstream from the viewpoint of image handling ease, safety, and the like. Also,
Depending on the developer used, this dry method is divided into two types: a magnetic two-component developer method in which toner and carrier are separated, and a magnetic one-component developer method in which the toner contains carrier. A magnetic one-component developer method is attracting attention from the viewpoint of ease of maintenance and miniaturization. As such a magnetic one-component developer method, there is a developing method as shown in FIG. This involves uniformly charging the outer circumferential surface of the photosensitive drum 1 with a photoconductor surface layer, as shown in the figure, and then exposing the outer circumferential surface to light through an image to be copied of a subject (not shown). An electrostatic latent image is formed on the outer peripheral surface. Next, a developing roll 3 containing a cylindrical magnet 2 is provided.
Toner is supplied from the toner supply device 4 to the outer peripheral surface of the developing roll 3, this toner is frictionally charged with a layer forming blade 5, and is uniformly formed into a thin layer and adhered to the outer peripheral surface of the developing roll 3. In this method, toner is caused to fly against the electrostatic latent image on the photosensitive drum 1, and the toner is attached to the electrostatic latent image to form a toner image, which is transferred to copy paper 6 and then fixed.

In FIG. 4, 7 is a magnetic pole.

The structure of the developing roll 3 used in the magnetic one-component developer method as described above is shown in FIG. A cylindrical magnet 2 having magnetic poles 7 of 5NSN, . extends left and right, end caps 11 are provided at both left and right ends of the sleeve 8 via bearings 10, and the left and right openings of the sleeve 8 are closed with the end caps 11. In order to improve toner transportability, the outer circumferential surface of the sleeve 8 of the developing roll 3 is roughened by processes such as shot blasting, honing, and polishing.

[Problems to be Solved by the Invention] However, in the above-mentioned developing roll, the outer circumferential surface of the sleeve is only roughened, so when the outer circumferential surface of the sleeve is worn out due to pressure contact with the layer forming blade, The surface gradually becomes mirror-like, and as a result, in a short period of time, it becomes difficult for toner to adhere to the developing roll, and the amount of toner conveyed by the developing roll decreases, making it impossible to make clear copies. . For this reason, recently, a developing roll that uses a synthetic resin filled with fibrous filler such as glass fiber and a sleeve molded from this mixture has been developed as a developing roll that can always maintain a rough surface. used in However, such a developing roll has a problem in that, since its strength is weak, the developing roll itself bends and deforms due to pressure contact with the layer forming blade, resulting in layered density unevenness in the copied image.

This invention was made in view of the above circumstances, and it is possible to maintain the appropriate roughness of the roll surface for a long period of time, to realize clear copies for a long period of time without causing deformation of the roll due to bending, and to maintain the quality of the copied image. The purpose is to provide a roll that does not cause density unevenness.

[Means for solving problems]

In order to achieve the above object, the electrophotographic developing roll of the present invention includes a cylindrical sleeve, a lid that closes the left and right openings of the sleeve, and a rotating shaft that rotatably holds the sleeve, The shaped sleeve is composed of a non-magnetic rigid cylinder and a thin layer of an organic polymer composition containing a fibrous filler formed on the outer peripheral surface of the cylinder, and the thin layer has a diameter of 3.
It has a structure in which micropores of ~10 μm are formed in a distributed manner.

That is, the present invention uses a highly rigid non-magnetic cylindrical sleeve body as a core body, and forms a sleeve by forming a thin layer of an organic polymer composition filled with a fibrous filler on the outer peripheral surface of the core body. ing. Therefore, even if the outer circumferential surface of the sleeve is worn out due to pressure contact with the layer-forming blade, the fibrous filler in the thin layer of the sleeve is exposed one after another, and this fibrous filler ensures that the surface roughness of the sleeve is always maintained at an appropriate level. At the same time, the non-magnetic rigid sleeve body prevents the sleeve itself from being bent. Therefore, the amount of toner conveyed by the developing roll is maintained at an appropriate level over a long period of time, allowing clear copies to be made for a long period of time, and density unevenness does not occur.

Next, examples will be described together with comparative examples.

[Examples 1 to 6, Comparative Examples 1 to 3] FIG. 1 shows an example of the present invention. In the figure, reference numeral 15 denotes a developing roll having the same shape as the developing roll 3 in FIG. semiconductive resin (volume resistivity 10°
The coating layer 16b has a thickness of 10'''Ω·cm).

In this coating layer 16b, an outer diameter of 5 to 1
A countless number of fibrous fillers 17 with a roughness of 0 μm are scattered, and the outer peripheral surface of the coating layer 16b is formed into a rough surface with a surface roughness of 3 to 10 μm. The other configuration is as shown in FIG.
It is similar to Therefore, the same parts are given the same reference numerals.

The sleeve 16 can be manufactured as follows. That is, based on a resol-type phenolic resin solution (manufactured by Sumitomo Durets Co., Ltd., Sumilite Resin TGK23) with a resin content of 60%, the following was added to 167 parts by weight (hereinafter abbreviated as "parts") of this phenolic resin solution. A solution 19, which is a phenolic resin composition, is prepared by adding fibrous fillers 17 such as glass fibers and carbon fibers, and other additives, according to the formulation shown in Table 1.

(Left below) Next, this solution 19 is placed in the dipping device 1 as shown in FIG.
8, and in this solution 19, an outer diameter of 29 m and an inner diameter of 2
An 8 m long sleeve body 16a is immersed, and its outer diameter is 30 m.
．． By repeating the immersion until 211I[I,
A coating layer 16b is formed on the outer peripheral surface of the sleeve body 16a. The coating layer 16b (the volume resistivity of the coating resin is preferably about 10 3 Ω·cti) is cured by heating this at a temperature of 150° C. for every 30 minutes. In this way, the sleeve 16
is obtained. At this time, the fibrous filler 17 is dispersed on the outer peripheral surface and inside of the coating layer 16b. The fibrous filler 17 dispersed inside the sleeve 16 is exposed to the surface due to abrasion of the surface of the sleeve 16.
The surface roughness of sleeve 16 is maintained properly regardless of wear of sleeve 16.

In this case, the surface roughness of the sleeve 16 is such that the fibrous filler 1
7 is affected by the outer diameter and content. Therefore, the fibrous filler 17 has an outer diameter of 5 to 30 μm, preferably 10 to 2 μm.
08m, the amount used is 1 of the base phenolic resin.
It is preferable to set the amount to 30 to 100 parts, preferably 40 to 60 parts.

Comparative Example 1 uses a stainless steel developing roll. The sleeve of Comparative Example 2 is based on a novolak type phenolic resin (Sumitomo Durets Co., Ltd., Sumilite Resin PR-50072) having a melting point of 90° C., and is manufactured as follows. That is, a mixture having the formulation shown in Table 1 is kneaded in a roll kneader whose rolls are heated to 110° C. and formed into a sheet. Next, this sheet-like material is crushed into pellets using a crusher, and the pellets are processed into pellets using a plunger set extrusion molding machine 20 as shown in FIG.
It is manufactured by forming a cylindrical body 16c with an outer diameter of 30.2 m and an inner diameter of 28 m at an extrusion pressure of kg/cd, and then cutting it into predetermined dimensions. In the sleeve of Comparative Example 3, the outer peripheral surface of the sleeve body 16a was coated with a phenolic resin solution containing no fibrous filler 17 in the same manner as in the above embodiment.

The amount of deflection due to deformation of the developing roll and the number of copies when the sleeves of the above examples and comparative examples were polished to have an outer diameter of φ30+m++, and were used in a commercially available copying machine to make copies. Table 2 shows the results of comparing the surface roughness of the sleeve and the quality of the copy.

(Margins below) As is clear from Table 2, all of the Example products can form good reproduced images even after making 50,000 copies, whereas Comparative Example 1.3 products If the number of sheets exceeds 10,000 and the surface of the sleeve wears, the amount of toner conveyed by the developing roll becomes too small, making it impossible to obtain good images. In addition, in Comparative Example 2, the developing roll was bent by the pressure contact of the layer forming blade 5 from the beginning of copying, and as a result, black streaks due to layered density unevenness appeared in the copied image.

In this way, the developing roll 15 does not have only the roll surface roughened like conventional developing rolls (the sleeve main body 16a is made of a cylindrical body made of non-magnetic metal, and the outer circumferential surface of the developing roll 15 is roughened). The sleeve 16 is coated with a resin composition containing a fibrous filler 17. Therefore, the sleeve 16 does not bend even when pressed by the layer forming blade 5, and even if the surface of the sleeve 16 is worn, it will not bend. The internal fibrous filler 17 is exposed, and the surface roughness of the sleeve 16 is maintained.Therefore, layered black streaks due to density unevenness do not appear in the copied image, and the surface of the developing roll 150 becomes mirror-finished. This makes it possible to make clear copies over a long period of time.

Note that as the fibrous filler 17, metal fibers, silicon carbide, potassium titanate whiskers, etc. can be used in addition to those in the above examples, and as the organic polymer composition, organic polymers that are soluble in solvents can be used. Any molecular material may be used, but resol type phenol, polyamide, unsaturated polyester, and epoxy resin are particularly suitable. This fibrous filler 1
Formation of a thin layer of the organic polymer composition containing 7 on the outer circumferential surface of the sleeve body 16a is not limited to coating by dipping as in the above embodiment, but may be formed by coating or other methods other than coating. You may.

Further, the roll of the present invention can be used not only in a copying machine but also in a word processor printer, for example.

〔Effect of the invention〕

Since the roll of this invention is constructed as described above, even if the surface of the sleeve is worn out, the fibrous filler distributed inside the sleeve is exposed, and the roughness of the sleeve surface can always be maintained. , and the sleeve does not bend and deform due to pressure contact of the layer forming plate. Therefore, the amount of toner conveyed by the developing roll can be maintained at an appropriate amount for a long period of time, and clear copies can be made for a long period of time, and density unevenness does not occur in the copied images.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of one embodiment of the present invention, FIG. 2 is an explanatory diagram of a method for manufacturing a sleeve, and FIG. 3 is a plunger 2 extrusion molding machine and a The figure is an explanatory diagram of development according to a conventional example, and FIG. 5 is a longitudinal sectional view of the conventional example. 9... Center shaft 11... End cap 15...
・Developing roll 16... Sleeve 16a... Sleeve surface 16b... Coating layer 17... Fibrous filler Figure 1 Figure 2 n ts3 Figure

Claims (3)

[Claims] (1) A cylindrical sleeve, a lid that closes the left and right openings of the sleeve, and a rotating shaft that rotatably holds the sleeve, and the cylindrical sleeve is connected to a non-magnetic rigid cylinder and the outer periphery of the sleeve. A thin layer of an organic polymer composition containing a fibrous filler is formed on the surface, and the entire thin layer has a diameter of 3 to 1 mm.
A roll characterized in that micropores of 0 μm are formed in a distributed manner. (2) The roll according to claim 1, wherein the fibrous filler has a diameter of 5 to 30 μm. (3) Organic polymer composition in which the content of fibrous filler is 100%
The roll according to claims 1 and 2, wherein the amount is 30 to 100 parts by weight.