JP2818962B2 - Rubber member for preventing double feed in paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a plain paper copier (hereinafter abbreviated as “PPC”),
The present invention relates to a double feed prevention rubber member used for a paper feeding device such as a facsimile.

[Prior Art] In a paper feeding device such as a PPC or a facsimile, a double feeding preventing means is conventionally taken so as to prevent two or more sheets from being fed one after another. For example, as shown in FIG. 1, when a rubber plate 2 for preventing double feeding is provided opposite to the paper feed roller 1 and two or more sheets of paper 3 are fed along the paper feed roller 1, The rubber plate 2 prevents the progress of the second and subsequent sheets of paper 3 (separation pad system). Or,
As shown in FIG. 2, the paper feed roller 1 and the tension roller pair
A rubber roller 6 for preventing double feed is provided opposite to the normal rotation roller 5 provided between the rollers 4 and 4a so as to prevent the paper 3 sent extra by the rubber roller 6 from advancing (reverse rotation). Roller separation method).

The rubber member used for the rubber plate 2 and the rubber roller 6 for preventing such double feeding has a high coefficient of friction and can be maintained over a long period of use, has abrasion resistance, and is free from contamination. In general, a rubber composition mainly composed of a polymer having low hardness and high durability such as polynorbornene or polyurethane is used.

[Problems to be solved by the invention]

However, in recent years, as the paper surface has become more smooth with the upgrading of paper, and surface treatment has been performed to impart gloss, when the rubber surface of the rubber member and the paper come into close contact with each other and separate. The static friction force and the dynamic friction force are alternately generated, and a large difference between the two friction forces causes a state slip phenomenon. And the so-called "squeal" is caused by the vibration.
(Unpleasant squeaking noise) is occurring, which is a problem. Further, there is also a problem that powder or the like scattered from the paper itself adheres to the rubber surface due to long-term use, and the friction coefficient rapidly decreases.

Therefore, in order to solve the above-described problems, increasing the hardness of the rubber composition, mixing a high lubricating material in the rubber composition, or applying a high lubricating material to the surface thereof has been performed. I have. However, none of these methods can maintain a predetermined coefficient of friction, and on the other hand, may lead to deterioration of durability and contamination, and no effective remedy has been found.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a double feed prevention rubber member which can prevent the occurrence of "squeal" due to the close contact between paper and rubber and can maintain smooth and trouble-free feeding for a long period of time.

[Means for solving the problem]

In order to achieve the above object, the rubber member for preventing double feed in the paper feeder of the present invention is a chlorosulfonated polyethylene represented by the above general formula, and has a chlorine content.
The whole is composed of a rubber composition containing 15 to 35% by weight as a main component, and has a hardness of 40 to 70 ° Hs.
It is configured to be set to.

[Operation] That is, the rubber member for preventing double feed in the paper feeding device of the present invention uses a special chlorosulfonated polyethylene having a reduced chlorine content as a rubber satisfying various required characteristics. . Therefore, the rubber elasticity of this member is limited to a low value, and the coefficient of friction of the surface in contact with the paper hardly changes even after long-term use. Become. Also, good paper handling can be performed on any smooth paper without generating "squeal".

 Next, the present invention will be described in detail.

The double feed prevention rubber member in the sheet feeding device of the present invention is:
The whole is constituted by a rubber composition containing chlorosulfonated polyethylene represented by the following general formula as a main component.

However, the chlorosulfonated polyethylene must have a chlorine content of 15 to 35% by weight (hereinafter abbreviated as "%"). Among them, those having a chlorine content of 20 to 25% are preferable. Examples of such chlorosulfonated polyethylene include Hypalon 4
5, Hypalon 6525 (manufactured by DuPont) and the like. Thus, the chlorine content was limited because the chlorine content was 15%.
%, Crosslinking of the rubber composition becomes insufficient, and conversely, 35%
This is because when the value exceeds, the squealing frequently occurs because the adhesion to the paper becomes high.

The rubber composition of the present invention may optionally contain, in addition to the chlorosulfonated polyethylene, additives such as a crosslinking agent (vulcanizing agent), a filler, a softener, and a coloring agent.

The rubber member of the present invention uses the above rubber composition material,
For example, it can be manufactured as follows. That is, the above rubber composition materials are blended in a predetermined ratio and uniformly kneaded. Then, the rubber portion can be three-dimensionally crosslinked by peroxide crosslinking or the like to obtain a target rubber member. This rubber member may be formed into a plate shape and used as the double feed prevention rubber plate 2 as shown in FIG. 1, or a cross-linked rubber layer may be formed on the surface of a roll core metal by a mold. Thus, the double feed prevention rubber roll 6 as shown in FIG. 2 may be used. However, the hardness (according to JIS A) of the rubber member is 40 to 70.
゜ It is necessary to adjust within the range of Hs, especially 45-60
It is particularly preferable to set ゜ Hs. By setting as described above, the required friction coefficient can be adjusted to 0.8 to 1.5.

The paper feeder incorporating the anti-double feed rubber plate or anti-double feed rubber roller thus obtained does not cause “squeal” when feeding paper, no matter what smooth high-grade paper is used, and also causes paper jams. No trouble such as And
This effect is not diminished by prolonged use.

 Next, examples will be described together with comparative examples.

Examples 1 to 3 and Comparative Examples 1 to 3 Using the materials shown in Table 1 below, rubber rolls for preventing double feed (see FIG. 2) were produced according to the above-mentioned method. Then, the coefficient of friction when the rubber roll was not used was measured, and the friction coefficient was measured again when the rubber roll was actually incorporated into PPC and used for copying 5,000 sheets. Also, the occurrence of "squeal" during the copying of 5000 sheets was observed, and the following 5
The evaluation was made according to a scale. The results are shown in Table 1 below.

<Evaluation of the state of occurrence of “squeal”>…: No occurrence of “squeal”.

○… almost no squealing.

Δ: Some “squeal” occurs, but there is no practical problem.

×: Problems due to “squealing” pose a practical problem.

XX: "Squealing" occurs frequently and is not practical.

[Examples 4 and 5] Using the same chlorosulfonated polystyrene as in Example 2, a rubber roll for preventing double feed was produced in the same manner as above. However, the hardness of each member can be reduced by compounding a reinforcing agent, etc.
The values were adjusted as shown in Table 2 below. These members were also evaluated in the same manner as described above, and the progress is shown in Table 2 below.

From the above results, it can be seen that "squeal" is effectively prevented in all of the examples. In particular, it can be seen that the effect of preventing "squeal" when using high-grade paper is remarkable.
Also, it can be seen that the coefficient of friction is a preferable value both when not used and after copying 5,000 sheets. On the other hand, it can be seen that all of the comparative examples have problems such as significant occurrence of "squeal" when high-grade paper is used.

〔The invention's effect〕

As described above, the rubber member for preventing double feeding in the paper feeder of the present invention uses a special chlorosulfonated polyethylene having a reduced chlorine content as a rubber satisfying the required characteristics. Therefore, the coefficient of friction of the surface in contact with the paper hardly changes even after long-term use, and the reliability of the paper feeding device is improved, and maintenance-free operation is possible.
Also, good paper handling can be performed on any smooth paper without generating "squeal".

[Brief description of the drawings]

FIG. 1 and FIG. 2 are illustrations showing the use of the double feed prevention rubber member to which the present invention is applied. 2 ... Rubber plate for preventing double feed, 6 ... Rubber roller for preventing double feed

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-180643 (JP, A) JP-A-62-26342 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B65H 1/00-1/30 B65H 3/00-3/68

Claims (1)

(57) [Claims] 1. A rubber composition mainly comprising a chlorosulfonated polyethylene represented by the following general formula and having a chlorine content of 15 to 35% by weight as a main component. A rubber member for preventing double feed in a sheet feeding device, the hardness of which is set to 40 to 70 ° Hs.