JPH0641354A - Paper transfer belt for copying machine - Google Patents

Abstract

PURPOSE:To provide the paper transfer belt used for a copying machine, having a small electric resistance value and excellent in the paper transfer property. CONSTITUTION:A rubber composition containing ethylene-propylene-diene terpolymer rubber (EPDM) and acrylonitrile-butadiene copolymer rubber (NBR) as main components is formed into a belt-like article and subsequently vulcanized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed belt for a copying machine used in an automatic document feeder of a copying machine.

[0002]

2. Description of the Related Art As a copying machine capable of continuously automatically copying a plurality of originals, there is one shown in FIG. That is, in this copying machine 1, a plurality of originals 3 are placed in a stacked state on the original placing table 2 arranged at the upper end of one side of the main body, with the front side facing down, and the originals are placed. When the table cover 4 is rotated around one end edge as shown by an arrow A in the figure and is tilted onto the document table glass 5, and a switch (not shown) is pressed to operate in that state, the back surface of the document table cover 4 is displayed. The provided white rubber paper feed belt 6 (endless elastic belt) travels in the direction of the arrow B to move the original 3 placed on the original placing table 2
Each time the copying is finished, the sheets are conveyed one by one from the upper side onto the original table glass 5. In this case, the copying paper 8 or 10 stored in the copying paper cassette 7 or 11 is conveyed into the copying machine 1 in response to copying.
Characters, patterns and the like on the surface of the original 3 are transferred and sent to the copy tray 9. The paper feed belt 6 of the copying machine 1 is configured to travel by the rotation of two drive rollers 12 and convey the original 3 as shown in FIG. The paper feed belt 6 needs a frictional force to convey the original document 3 and needs a document detachability for discharging the original document 3. As a material for forming the paper feed belt 6, a terpolymer of ethylene-propylene-diene rubber (hereinafter abbreviated as "EPDM") and epichlorohydrin-ethylene oxide-allyl glycidyl ether (hereinafter referred to as "ECO") has been conventionally used. (Abbreviated) is used as a main component.

[0003]

However, the paper feed belt 6 formed by using the above rubber composition as a forming material has the following problems. If the dirt transferred from the original to the belt surface, such as pencil dust, is wiped off with a cleaning solvent, the belt itself stretches,
There is a problem that the belt slips at the time of driving and the paper feeding property deteriorates. The belt is usually formed by a molding die, but since Cl is contained in the ECO, the die will be corroded if a large amount of this is used. Therefore, it is necessary to reduce the amount of ECO compounded.
As a result, the electrical resistance becomes high, and the document sheet is electrostatically adsorbed on the belt, which deteriorates the releasability of the document.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a paper feed belt for a copying machine, which has a small electric resistance value and is excellent in paper feedability.

[0005]

A paper feed belt for a copying machine according to the present invention is made of EPDM and a rubber composition containing acrylonitrile-butadiene rubber (hereinafter abbreviated as "NBR") as main components and formed into a belt shape. Take the configuration of being.

[0006]

That is, the present inventors have conducted a series of studies in order to obtain a paper feed belt having excellent paper feedability without increasing the electric resistance value. As a result, as a material for forming the paper feed belt, a rubber composition containing EPDM and NBR as main components was used in place of the rubber composition containing EPDM and ECO as main components, which has been conventionally used. Then, when the rubber composition containing EPDM and NBR as the main components is vulcanized and molded, corrosion of the molding die due to conventional ECO does not occur, and in consideration of this, prevention of corrosion of the die due to ECO is taken into consideration. As a result, they have found that there is no increase in the electric resistance value caused by a high compounding amount of EPDM and that the elongation due to the wiping of the cleaning solvent is suppressed, and the present invention has been reached.

Next, the present invention will be described in detail.

The paper feed belt of the copying machine of the present invention is EP
It is produced by forming a desired belt shape using a rubber composition containing DM and NBR as main components.

The EPDM is not particularly limited, and a conventionally known one can be used.

The NBR is not particularly limited and any conventionally known one may be used.

The EPDM (X) and NBR (Y) are mixed in a weight ratio of X / Y = 90/10 to 30/70.
It is preferable to set the ratio to. That is, X is 90
This is because when the value exceeds Y (Y is less than 10), the electric resistance increases, and conversely, when X is less than 30 (Y exceeds 70), the whiteness of the belt itself tends to decrease.

In addition to the above components, other additives such as a vulcanizing agent, a filler, a softening agent, a vulcanization accelerating aid, an antiaging agent and a processing aid are appropriately added to the rubber composition. .

The paper feed belt of the copying machine of the present invention is obtained, for example, as follows. That is, the EPDM
A rubber composition is prepared by mixing NBR, NBR, and other additives in a predetermined ratio and kneading. Then, using the above rubber composition, it is filled in a molding die and vulcanization conditions (1
Vulcanization is performed at 60 ° C. for 30 minutes to obtain a paper feed belt having a desired shape.

[0014]

As described above, the paper feed belt of the copying machine of the present invention is formed of a rubber composition containing EPDM and NBR as main components. Therefore, in consideration of the corrosion of the molding die by the conventional ECO and the prevention of the corrosion of the die due to the conventional ECO, the increase in the electric resistance value caused by the high compounding amount of EPDM does not occur, and the cleaning solvent The stretching of the belt due to wiping is suppressed. Therefore, when this copy paper sheet feed belt is used, the charge adsorption phenomenon of the copy paper due to the high electric resistance value and the slip phenomenon at the time of driving due to the extension of the belt are prevented, and good paper feed property is realized.

Next, examples will be described together with comparative examples.

[0016]

Examples 1 to 4, Comparative Examples 1 and 2 Tables 1 and 2 below.
A rubber composition was prepared by blending the components shown in Table 1 in the proportions shown in the table and kneading. Then, this rubber composition was filled with the above rubber composition using a molding die having a predetermined shape and vulcanized at 160 ° C. for 30 minutes to obtain a paper feed belt for a copying machine.

[0017]

[Table 1]

[0018]

[Table 2]

The breaking strength, breaking elongation and surface electric resistance value (23 ° C. × 55% RH) of each example product and comparative product thus obtained were measured. Further, the above-described example product and comparative example product were incorporated into an automatic copying machine and operated to cause the paper to be fed, and the paper feeding property was evaluated. further,
The corrosiveness of the mold was evaluated using the above rubber composition. The results are shown in Tables 3 to 5 below.

The breaking strength and breaking elongation are measured according to JIS K.
6301.

The surface electric resistance value is 23 ° C. × 55% R
It was measured according to JIS K 6911 under the condition of H.

The paper feeding property was evaluated as follows. That is, the case where the paper feed belt for a copying machine made of the above rubber composition was incorporated into an automatic copying machine, wiped 10 times with a cleaning solvent, and after 5 minutes, the paper was fed, and the paper was fed without the belt slipping. The case where the belt slipped and the paper was not fed was evaluated as x.

The mold corrosiveness was evaluated as follows. That is, after vulcanizing the product for 50 shots or more,
The mold was left for 24 hours. Then, the surface state of the mold was visually inspected, and when the rust was not generated, it was marked with ◯, and when the rust was generated and corroded, it was marked with x. By the way, one shot has a total vulcanization time of 30 minutes + preparation 5 minutes of 35 minutes.

[0024]

[Table 3]

[0025]

[Table 4]

[0026]

[Table 5]

From the results shown in Tables 3 to 5 above, all of the comparative examples had poor paper feeding properties, and the mold was corroded. On the other hand, all the example products were excellent in the paper feeding property, and the mold corrosion was also evaluated to be good.

[Brief description of drawings]

FIG. 1 is a perspective view of a copying machine.

FIG. 2 is a front view of a paper feed belt portion used in the copying machine.

Claims (1)

[Claims] 1. An ethylene-propylene-diene rubber,
A paper feed belt for a copying machine, comprising a rubber composition containing acrylonitrile-butadiene rubber as a main component and formed into a belt shape.