JPH02202430A - Manufacture of semi-conductive roll - Google Patents

Abstract

PURPOSE:To obtain a stabilized electric resistance level and prepare a semi- conductive high molecular layer without surface pollution with an eluted material by using a semi-conductive high molecular composition dispersed in the complex ionized state of a conductive material in a matrix. CONSTITUTION:A high molecular compound having an ether bonding in repeating unit is used as a matrix, and a semi-conductive high molecular composition containing 0.1-10pts.wt. of perchlorate to 100pts.wt. of said matrix component is prepared. A conductive high molecular composition is formed into a film tube shape and a roll having a conductive elastic material layer 3 formedon the outer periphery of a shaft is manufactured. A tube-shaped molding material is covered around a roll having a conductive elastic material layer 3, while air is blown into the tube-shaped molded material. In other words, air is introduced into a tube 10 to expand the same into a cylindrical shape. Then, the tube 10 is moved and covered on the outer periphery of a shaft 10 having the conductive elastic material layer 3 to manufacture a semi-conductive roll having a filmy semi-conductive high molecular layer 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing semiconductive rolls used in electrophotographic copying machines and the like.

[Conventional technology]

Generally, semiconductive rolls such as charging rolls and developing rolls of electrophotographic copying machines, or film conveying rolls of film manufacturing equipment, have a semiconductive layer directly attached to the outer periphery of a metal shaft 1, as shown in FIG. Either a single-layer structure in which a polymer layer 2 is formed, or a conductive elastic layer 3 made of conductive resin or rubber is first formed on the outer periphery of the shaft body 1, and a half-layer structure is formed on the outside, as shown in Fig. 4. It has a two-layer structure in which a conductive polymer layer 2 is formed.

Among these, the two-layer structure semiconductive roll is, for example,
It can be obtained as follows. That is, first, a conductive elastic material is extruded around the outer periphery of the shaft 1, or the shaft 1 is placed coaxially within a cylindrical cavity and then molded with a mold to form a conductive elastic material around the outer periphery of the shaft 1. A conductive elastic layer 3 is formed. Next, a semiconductive polymer composition is extruded around the outer periphery of this conductive elastic body N3. However, in such extrusion molding, the semiconductive polymer layer 2
Therefore, it is not possible to obtain a roll with highly regulated capacitance because it is not possible to obtain a roll with a highly regulated capacitance. A method is used in which the shaft 1 on which the conductive elastic layer 3 is formed is immersed in this liquid to form a film, and then dried to form the semiconductive polymer layer 2.

[Problem that the invention seeks to solve]

However, the dipping method described above has the disadvantage that it is difficult to form a film of uniform thickness, and it is also difficult to set the viscosity of the dipping liquid, the dipping time, etc.

Conventionally, the semiconductive polymer composition that becomes the film has a matrix of rubber or resin with a certain elasticity, and conductive particles such as carbon or metal powder are dispersed in this matrix. However, in this composition, the conductive particles dispersed in the matrix contact each other to develop conductivity, so it is not always possible to obtain uniform contact between the particles, and it is difficult to achieve an appropriate level of electrical resistance. The problem is that it is difficult to obtain. Moreover, even when pressurized after molding, the degree of contact between particles changes and the electrical resistance changes, so there is a problem that the electrical resistance level tends to become unstable during use.

Therefore, recently, compositions incorporating antistatic agents mainly composed of surfactants and highly dielectric liquids such as tetrabutoxyphosphate (TBXP) have been developed as compositions whose semiconductivity can be more easily controlled. Those that have been kneaded are now used.

However, these compositions cannot obtain low electrical resistance values in the presence of a certain amount of moisture because the flow of charge depends on the amount of water present in the system, and furthermore, the resistance decreases in low humidity environments. The problem is that the increase in value is large. Furthermore, since these compositions have a small conductive effect and are used in relatively large amounts, when the shaft body 1 is immersed in the dip liquid to form a film and then dried as described above, the film drying process is difficult. Since conductive inclusions such as surfactants and highly dielectric liquids sometimes ooze out from within the composition, there is also the problem that the resulting roll surface is likely to be contaminated unless the drying conditions are carefully selected.

This invention was developed in light of these circumstances, and is a two-layer half-layer with a stable electrical resistance level unaffected by humidity, pressure, etc. as a whole, and a highly regulated capacitance. The purpose of the present invention is to provide a method for manufacturing a semi-conductive roll that allows the conductive roll to be easily manufactured without causing surface contamination.

[Means for solving problems]

In order to achieve the above object, the method for manufacturing a semiconductive roll of the present invention uses a polymer compound having an ether bond in the repeating unit as a matrix, and this matrix component 1
A step of preparing a semiconductive polymer composition containing 0.1 to 10 parts by weight of perchlorate per 00 parts by weight, and molding the semiconductive polymer composition into a thin film tube shape. a step of preparing a roll having a conductive elastic layer formed on the outer periphery of the shaft body; and a step of preparing a roll having a conductive elastic layer formed on the outer periphery of the shaft body; The structure includes a step of externally fitting the roll onto the roll.

[Effect]

That is, the present inventors conducted a series of studies in order to obtain a semiconductive roll with a stable electrical resistance level unaffected by humidity, etc., and with highly limited capacitance, without causing surface contamination. I did it. As a result, as a semiconductive polymer composition forming a semiconductive polymer layer, a polymer compound (including rubber, resin, and a mixture thereof) having an ether bond in the repeating unit is used as a matrix, and in this matrix, When a specific amount of perchlorate is mixed in, the lone pair of oxygen atoms in the ether bond in the matrix acts on the perchlorate, and the perchlorate Probably because the salt is dissociated into positive metal ions and negative perchlorate ions, a conductive ionic substance is formed without the intervention of water, and each of the above ions is fixed within the matrix and oozes out to the surface of the composition. I found out that there is nothing wrong with that. This semiconductive polymer composition not only exhibits a very stable electrical resistance level, but also has excellent mechanical strength due to the high proportion of matrix components, and can be handled by being formed into a thin film tube. I understand. Therefore, if this tube is kept hollow by blowing air into the tube and is placed over the outer periphery of the conductive elastic layer,
The inventors have discovered that it is possible to easily obtain a semiconductive roll with a low capacitance value, and have thus arrived at this invention.

Next, the present invention will be explained in detail.

In this invention, as a material for forming the semiconductive polymer layer 2 of the two-layer structure semiconductive roll shown in FIG. 4, a polymer compound having an ether bond in the repeating unit is used as a matrix, A special semiconducting polymer composition containing chlorate is used.

The polymer compound having an ether bond in its repeating unit is polyethylene oxide.

polypropion oxide, epichlorohydrin rubber,
epichlorohydrin-ethylene oxide copolymer rubber,
Examples include urethane resins, nylon-urethane copolymer resins, etc., and these may be used alone or in combination of two or more. Among these, nylon-urethane copolymer resins (nylon/urethane 90/10~
50150) is suitable.

In addition, examples of the perchlorate to be contained in the matrix include sodium perchlorate, potassium perchlorate, etc. These perchlorates may be used alone or in combination of two or more. The acid salt is represented by the general formula below.

M-(40, (M is a metal atom) In the present invention, the perchlorate is 0% per 100 parts by weight (hereinafter abbreviated as "parts") of the matrix component.
．． It is necessary to mix within the range of 1 to 50 parts. That is, if it is less than 0.1 part, it is substantially ineffective in lowering the resistance and the resistance becomes the same as that of the matrix component, and if it exceeds 50 parts, it becomes undesirable and a problem arises in durability.

In the present invention, a two-layer structure semiconductive roll (see FIG. 4) is obtained using the above-mentioned semiconductive polymer composition, for example, in the following manner. That is, first, a conductive elastic material such as ethylene-propylene-diene rubber (EPDM) is extruded onto the outer periphery of a metal shaft 1 to form a conductive elastic layer 3.
form a number.

On the other hand, the perchlorate and the polymer compound as the matrix component are sufficiently kneaded to prepare a powder mixture, and then extruded into a thin film tube using an extrusion molding machine. This tube is a thin film with poor shape retention, so it is flattened under normal conditions. Therefore, this tube is coaxially arranged near the shaft body 1 on which the conductive elastic body N3 is formed, and the first tube is placed inside the tube 10.
As shown by arrow P in the figure, air is pumped in to inflate it into a cylindrical shape. Then, as shown by the arrow Q, the tube lO is moved, and the semiconductive material on which the thin film-like semiconductive polymer layer 2 is formed is placed over the outer periphery of the shaft body 1 on which the conductive elastic layer 3 is formed. You get a roll. In this way, the semiconductive polymer composition can be made into thin film tubes and handled because it contains a small amount of conductive substance (perchlorate) and the characteristics of the matrix component. This is only because it is maintained. Therefore, according to this manufacturing method, a very thin semiconductive polymer layer 2 can be formed without using the dipping method.

In addition, in the above manufacturing method, the thickness of the tube 10 made of the semiconductive polymer composition is usually set within the range of 0°1 to 3 mm, although it depends on the capacitance desired to be imparted to the intended roll. is suitable.

Also, the amount of air blown to inflate the tube 10 is 1 to 501! ,/second. However, if the tube 10 is thicker and less flexible, it will be difficult to cover the conductive elastic layer 3 as it is, so as shown in FIG. It is preferable to fold and close the tube 10a, blow in a large amount of air in this state, and expand the tube 10 from the inside to slightly enlarge the inner diameter and cover the tube 10a. The amount of air blown in such a case is preferably set to about 0.2 to 101/sec, although it depends on the thickness of the tube 10.

In the semiconductive roll thus obtained, the metal atoms M of the perchlorate and the oxygen atoms constituting the ether bond of the matrix component are arranged in the semiconductive elastic layer 2, which is the outermost layer. They bond to form complex ions as shown below, and the roll surface exhibits semiconductivity.

~0-J/S+0\no Such a complex ion is formed because the lone pair of electrons (see the above formula) of the oxygen atom constituting the ether bond acts on the metal atom M.

Therefore, this semiconductive roll exhibits conductivity through ion dissociation in the semiconductive elastic layer 2 without the presence of moisture, so it has a very stable electrical resistance level regardless of the environment. In particular, it has the advantage that the increase in electrical resistance is small even when placed in a low-humidity environment.There is no surface contamination due to conductive material exuding from the composition, and the semiconductive polymer 182 is extremely Because of its thinness, it is suitable for applications where the roll surface capacitance is highly regulated.

Next, examples will be described together with comparative examples.

[Examples 1 to 10, Comparative Examples 1 to 7] According to the table below, each raw material was blended in the following proportions to obtain various semiconductive polymer compositions. Then, this composition was extruded to a thickness of 0.5 mm and an outer diameter of 17IIIa.
A tube was made. However, when the matrix of the composition was rubber, heat vulcanization was performed according to a conventional method. On the other hand, conductive carbon black (trade name: Ketchenblack Acid E) was added to ethylene-propylene-diene rubber (EPDM).
A conductive rubber composition (hardness: 40°, volume resistivity: 103 Ωcm) containing C1 (manufactured by Japan EC Co., Ltd.) is extruded and molded onto the outer periphery of a metal shaft with a diameter of 10 m, and after vulcanization, it is polished to a thickness of 3 am. A roll with a conductive elastic layer was formed. Then, as shown in FIG. 1, the semiconductive polymer composition tube 10 is placed over the outer periphery of the conductive elastic layer 3 of this roll to form a semiconductive polymer N2, and as shown in FIG. A roll with the structure shown was obtained.

Using the above roll, the electrical resistance was measured when it was left in environments with different temperatures and humidity for more than one night. In addition, in order to evaluate the variation in electrical resistance within the roll, silver paste was applied to five locations on the outer surface of the semiconductive polymer layer 2 for 10 minutes.
A mm square electrode was drawn (with a guard electrode), and the resistance between the metal shaft 4 and the electrode was measured. Furthermore, voltage resistance, stain resistance, and durability were examined according to the following methods.

Voltage Resistance> The roll was rotated in close contact with a metal roll (outer diameter: 30 mm) under a constant load, a DC voltage was applied between the roll and the metal roll, and the voltage at which spark discharge occurred was examined.

<Stainability> The above roll was pressed against the organic photoreceptor of a commercially available electrophotographic copying machine with a constant load, left in an atmosphere of 32°C x 85% RH for 72 hours, and the condition of the photoreceptor surface was observed. The presence or absence of was investigated.

<Durability> The roll was pressed against a metal roll (outer diameter 30 mm) under a constant load, and a durability test was conducted 100,000 times at a rotation speed of 60 rpm.

These results are also shown in the table below.

(The following is a blank space) From the above results, it can be seen that the electrical resistance values of all the example products are hardly influenced by the environment. Moreover, the variation in resistance within the roll is small. Moreover, the performance of voltage resistance, stain resistance, and durability is good.

〔Effect of the invention〕

As described above, according to the method for manufacturing a semiconductive roll of the present invention, a special composition in which a conductive substance (perchlorate) is dispersed in a complex ionized state in a matrix as a semiconductive polymer composition is used. Because of the use of a material, it is possible to obtain a semiconductive polymer layer that exhibits a very stable electrical resistance level and is free from surface contamination due to oozing substances. Moreover, since the amount of conductive substance blended in the composition, which is a material for forming a semiconductive polymer layer, is small, the composition can be made into a thin film tube and handled. A semiconductive roll with a 2N structure can be easily obtained by simply covering the elastic material layer.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the procedure for forming a semiconductive polymer layer in one embodiment of the present invention, FIG. 2 is an explanatory diagram showing a different procedure, and FIG. 3 is an explanatory diagram showing the general structure of a semiconductive roll. FIG. 4 is a longitudinal sectional view showing another configuration. 1... Shaft body 2... Semi-conductive polymer layer 3... Conductive elastic layer 10... Tube patent applicant Tokai Rubber Industries Co., Ltd. agent Patent attorney Yukihiko Nishifuji

Claims (1)

[Claims] (1) A polymer compound having an ether bond in the repeating unit is used as a matrix, and this matrix component 100
A step of preparing a semiconductive polymer composition containing 0.1 to 50 parts by weight of perchlorate, and a step of molding the semiconductive polymer composition into a thin film tube shape. a step of preparing a roll having a conductive elastic layer formed on the outer periphery of the shaft body; and a step of preparing a roll having the conductive elastic layer formed thereon while blowing air into the tubular molded body. A method for manufacturing a semiconductive roll, comprising the step of fitting the roll onto the outside of the roll.