JPH0825232B2 - Seamless semi-conductive belt - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seamless semiconductive belt having a uniform electric resistance value.

[0002]

2. Description of the Related Art Conventionally, seamless semiconductive belts exist, but they have problems such as variations in electric resistance value and deterioration of mechanical properties due to mixing conductive fillers.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention In the method of manufacturing a seamless semi-lightning conductive belt, the extrusion molding method of a seamless belt has a drawback that the electric resistance value fluctuates, and it is difficult to obtain a product having good dimensional accuracy. However, the centrifugal molding method tends to cause a difference in electrical resistance between the surface and the inner surface due to the difference in specific gravity between the particles of the mixed material. In order to solve the above-mentioned problems, the present inventors have made it possible to provide a seamless semiconductive belt having an electric resistance value within a fixed range of 1 and small and having excellent mechanical strength.

[0004]

The feature of the present invention lies in that ethylene-tetrafluoroethylene copolymer (ETFE)
And / or ethylene-3-fluorochloroethylene (ECTF
A belt obtained by mixing E) as a main component with a conductive filler, extruding a film into a tube, and then cutting the material into a predetermined length in a direction perpendicular to the axial direction. The volume electric resistance value is in the range of 10 ⁵ to 10 ¹⁷ Ωcm, preferably 10 ⁸ to 10 ¹⁴ Ωcm, and the maximum value of the volume electric resistance value in each of the above parts is 1 as the minimum value.
It is characterized by being up to 100 times.

The ethylene-4 fluoroethylene copolymer (ETFE) and / or ethylene-3 fluoroethylene chloride (ECTFE) in the present invention is not particularly limited, but for example, if an extrusion grade is used as the kind thereof. Good. The shape is also not particularly limited, and granular pellets, powdery ones and the like can be appropriately used. The seamless semi-conductive belt has an ethylene-4 fluoroethylene copolymer and / or an ethylene-3 fluorochloroethylene copolymer as a main component, as long as the conductivity and the mechanical properties are not deteriorated. Other resins such as acrylic resins and polymethylmethacrylate may be added, and there is no particular limitation to this.

As the conductive filler to be added to the ethylene-4fluoroethylene copolymer and / or the ethylene-3fluorochloroethylene copolymer for imparting conductivity, a conductive / semiconductive fine particle is used. The powder is not particularly limited, but carbon black such as Ketjen black (conductive furnace type carbon black) and acetylene black, stannic oxide, indium oxide, potassium titanate, black titanate, whisker titanate, etc. Any conductive fine powder may be used. The amount of the conductive filler mixed is not particularly limited and may be appropriately selected according to the electric resistance value, and usually 5 to 20% by weight based on the weight of the resin. In some cases, conductive carbon and a metal oxide may be used in combination in order to stabilize the volume electric resistance value, but this is not particularly limited.

In the present invention, in addition to the ethylene-tetrafluoroethylene copolymer base and / or the ethylene-3fluoroethylene chloride chloride copolymer and the conductive filler component, suitable components may be blended depending on the application. . For example, a lubricant such as wax, silicone oil, calcium stearate, a low molecular weight ethylene-4 fluoroethylene copolymer, an ethylene-3 fluorochloroethylene copolymer and an oligomer can be blended. Lubricant is usually 10% by weight based on the total weight of the raw materials used
Below, it is preferable to add about 0.5% to 1.5% by weight, but the amount to be added is not particularly limited.

In order to improve creep characteristics and durability, it is often preferable to mix an inorganic filler or an organic filler in the seamless semiconductive belt according to the present invention, but there is no particular limitation, and talc, which can be mixed, is used as a filler that can be mixed. In consideration of the surface accuracy of the film such as whisker titanate and mica, it is preferable to use one having a particle size of 1 to 2 μm. The organic filler is not particularly limited, but liquid crystal polymer, aramid fiber and the like can be exemplified. The amount of the filler added is not particularly limited and is generally 20% by weight or less, preferably about 5 to 20% by weight, but it is not always necessary to add the filler, and it is not necessary to add it.

The seamless semiconductive belt according to the present invention can be manufactured as follows, but it is merely an example and the manufacturing method is not limited. The extruder used is not particularly limited, but for example, mixing 2
A shaft extruder or the like can be exemplified, and it is often preferable to use a Hastelloy C or H alloy type extruder having excellent corrosion resistance because it is used for molding a fluororesin.

First, the respective raw materials are blended. The blending method is not particularly limited, and for example, a mixing blending method can be used. The mixing blend method is not particularly limited, but in consideration of dispersing conductive carbon, an extruder having, for example, a twin screw is preferable. In order to further improve the dispersibility, a hybrid is prepared by physically and mechanically mixing the resin (powder is more preferable) and powder of metal oxide, conductive carbon or the like to form a composite of the resin and conductive powder. Mixing by a method such as a titration system can be exemplified, but there is no particular limitation to this. The raw material thus mixed and blended is usually extruded into a belet shape. However, if the raw material is used as it is, foaming may occur during film formation. Therefore, if necessary, the moisture content should be dehumidified and dried to 0.05% or less. Preferably. The blended and, if necessary, pelletized raw material is then deposited on a tubular film. The film referred to in the present invention also includes a sheet-like thick film.

The film formation method is not particularly limited, but a method of extrusion film formation from an annular die is preferable. In extrusion film formation from an annular die, in order to obtain dimensional accuracy of a constant diameter and a constant film thickness, it is preferable to regulate by a sicing method such as inside or outside cooling. The cooling temperature of such a sizing portion is particularly important, and the electric resistance value changes depending on the temperature of the cooling water and the material of the sizing portion, so that caution is often required. The temperature of the cooling water circulated in the sizing tubular body in the present invention is not particularly limited, but it is usually 0 to 90 ° C, preferably 20 to 60 ° C. Further, it is often desirable to keep the water pressure and the water amount constant. Further, since the fluctuation of the temperature of the cooling water causes the fluctuation of the electric resistance value, it is often preferable to control the temperature to ± 2 to 3 ° C, for example.

The extruded tubular film is not particularly limited, but it is preferable to take it out without making a crease. For example, it is preferable to use a pair of soft endless track type conveyors while gently pressing them down so that no folds remain.

The volume electric resistance value of the obtained film is mainly determined by the amount of the conductive filler to be blended, but the volume electric resistance value of each part of the film varies depending on the film forming conditions. Therefore, it is more preferable to set the fluidity viscosity of the blended raw materials, the pressure in the extruder, and other factors within a predetermined range in order to keep the width of the resistance fluctuation of the volume electric resistance within a certain range.

For this reason, in the extruder, it is desirable to accurately control the shape of the screw, the extrusion amount and the temperature. At this time, a gear pump may be used to control the pressure of the extruder. Further, this variation in the volume electric resistance value tends to increase in the direction perpendicular to the extrusion direction (the axial direction of the tube) (circumferential direction of the tube). It is preferable to control the temperature in the die in detail. For example, it is preferable to control the resin temperature in the die to ± 1 ° C, more preferably ± 0.5 ° C.

When higher dimensional accuracy is required, the dimensional accuracy may be imparted by, for example, regulating the extruder with a sizing guide or stretching. When the stretching is performed, it is preferable to adjust the conditions in advance because the volume electric resistance value varies depending on the stretching ratio in the length and width (axial direction and circumferential direction of the tube). The stretching ratio can be, for example, 1 to 5% in length and width, and the stretching temperature is 60 to 1
80 ° C., preferably 120 to 150 ° C. The stretching ratio and the temperature may be appropriately selected, but the variation in resistance is smaller at a low temperature and a lower ratio, but this is not the limitation.

When the surface precision such as the smoothness of the film surface is deteriorated by the aggregation of the conductive filler, a filter may be used near the break curve rate in the extruder. Such a filter has a mesh of 10-20
Examples of the filter include a basket type of μ and a leaf type of 5 to 20 μ of mesh, but the type and mesh of the filter are not particularly limited.

When surface releasability is required, surface accuracy may be improved by blending silicon oil, silicon powder, and tetrafluoroethylene-based polymer. If necessary, it is possible to use surface coating or vapor deposition to use, but in this case, since the fluorine resin is used, there is releasability and the adhesion of the paint is poor, so the surface It may be etched. Examples of the etching method include chemical etching, plasma etching, corona treatment and the like.

The use of the present invention is not particularly limited,
It was useful as various functional belts for copiers and the like, and was suitable when used as a transfer belt or an OPC (photosensitive) belt as an example. Here, in the present invention, each belt
Volume electric resistance value of 10 ⁵ to 10 ¹⁷ Ωcm
Is within the range, and the volume electric resistance value of each part is the maximum.
Explain why the maximum value is in the range of 1-100 times the minimum value
It First, the seamless semi-conductive belt of the present invention is
As noted, for example, as a transfer belt in a copying machine
The basic principles of a copying machine
And whether solid ink, commonly called toner, is a photoreceptor
Is transferred to the transfer belt by the action of static electricity (primary transfer
Image), the toner transferred in this way is further transferred to the transfer belt.
Is transferred to paper (secondary transfer) to make a copy image
It is. In the present invention, volume electricity in each part of the belt
The resistance value is set to be in the range of 10 ⁵ to 10 ¹⁷ Ωcm by 1
If it is less than 0 ⁵ Ωcm, electricity will flow on the belt.
Static electricity does not easily occur on the belt, and suitable primary transfer,
This is because the secondary transfer is not performed, and it exceeds 10 ¹⁷ Ωcm.
Belt becomes too strong, and electrostatic
I feel overwhelmed, and also suitable primary transfer and secondary transfer
Is not done. Next, the body in each part of the belt
The maximum value of the product electrical resistance is in the range of 1 to 100 times the minimum value.
The reason is that if the value exceeds 100 times, there will be large variations in resistance.
It becomes too difficult to perform suitable primary transfer and secondary transfer.
This is because. That is, in the above-mentioned primary transfer, the resistance value varies.
If the spot light becomes too large, static electricity may be generated in areas with high resistance.
It is easy to get overwhelmed, and static electricity can escape in places with low resistance.
Since it is easy to remove, there is a variation in the amount of static electricity.
The toner that has been transferred onto the transfer belt may also vary,
You will not be able to get a good copy image.
In the secondary transfer, the variation of the resistance value becomes too large.
Contrary to the above, static electricity is too strong at the places with high resistance.
Shows a tendency to stick to the transfer belt and retransfer to paper
However, it is less likely to be performed compared to the place where the resistance value is low.
-This is because the images vary. Therefore,
In the present invention, the variation of the volume electric resistance value is
It shall be within the range. It should be noted that in the present invention,
All units of air resistance are expressed in Ωcm for convenience, but in reality
Is Ω · cm.

The present invention will be described below based on examples.

[0020]

【Example】

Example 1 Ethylene-4 Fluoroethylene Copolymer (ETFE) 94
Wt% and 6 wt% Ketjen Plac were blended by a hybridization system in a nitrogen gas atmosphere. The obtained blended product was subsequently charged into an extruder having a twin screw in nitrogen gas, and granulated into a pellet-shaped raw material. This pelletized raw material is L / D = 6 of 6
It was put into a 5 mm extruder, guided to an annular die through a gear pump, and melt-extruded into a tube shape. Then, it was cooled from the inside with a sizing sleeve having an outer diameter of 60 mm and taken off, and a film having a thickness of 160 μ was formed. At this time, the temperature inside the circular die is 300 ± 0.5.
The temperature was controlled at ° C. Further, a 20-mesh basket-shaped stainless steel filter was installed between the screw tip of the extruder and the die. The tubular film thus obtained was stretched at a temperature of 140 ° C. in the longitudinal direction and the circumferential direction by 3% each. Then, the stretched film was cut into a length of 350 mm to obtain a belt. This belt has an inner diameter of 1
The dimensional accuracy of 65 mm and thickness 150 μ was also excellent. The volume electric resistance value of this belt is in the range of 1 × 10 ¹⁰ to 1 × 10 ¹¹ Ωcm when a voltage of 100 v is applied, voltage dependency is not recognized, and the maximum value of the volume electric resistance value in each part of the belt is the minimum value. Was 10 times. The physical properties of this film are shown in Table 1.

Example 2 Polyethylene-4 Fluoroethylene Copolymer (ETFE)
84% by weight, 6% by weight of Ketchinine black, and further 10% by weight of fine talc (particle size: 2 to 3 μ) were blended by a hybridization system to obtain a seamless belt in the same manner as in Example 1. The film thus obtained has a volume electric resistance value of 1 × 10 5 when a voltage of 100 V is applied.
The range was ¹⁰ to 1 × 10 ¹¹ Ωcm, voltage dependency was not recognized, and the maximum value of the volume resistance value in each part of the belt was 10 times the minimum value. Table 1 shows the physical properties of the obtained film.

[0023]

[Table 1]

[0024]

Since the seamless semiconductive belt according to the present invention is excellent in electrical characteristics, mechanical characteristics and heat resistance, it can be expected to be applied to various fields in the future. For example, it can be used as a functional belt for a copying machine and the like, and its effect is remarkable without causing dimensional deformation.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location B29L 29:00 C08L 27:12 (72) Inventor Satoshi Wanaka Nakano, Kunan-cho, Konan-shi, Aichi Prefecture No. 1 Gunze Co., Ltd. Engineering Business Center-Inspector Hitoshi Miura

Claims (1)

[Claims] 1. A material comprising an ethylene-4-fluoroethylene copolymer and / or an ethylene-3fluoroethylene chloride chloride copolymer is extruded into a tube shape, and then cut into a predetermined length in the direction perpendicular to the axial direction. The obtained belt, wherein the volume electric resistance value of each part of the belt is in the range of 10 ⁵ to 10 ¹⁷ Ωcm, and the maximum value of the volume electric resistance value of each part is in the range of 1 to 100 times the minimum value. Characteristic seamless semi-conductive belt.