JP5155286B2 - Paper feed roller - Google Patents

Description

  The present invention relates to a paper feed roller used for paper feed in an electrostatic copying machine, various printers, and the like.

  For example, various paper feed rollers are incorporated in a paper feed mechanism in devices such as an electrostatic copying machine, a laser printer, a plain paper facsimile machine, an ink jet printer, and an automatic cash dispenser (ATM). Examples of the paper feed roller include a paper feed roller, a transport roller, a platen roller, and a paper discharge roller that rotate while contacting paper (including a plastic film, etc.) and convey the paper by friction. It is done.

Conventionally, as the paper feeding roller, for example, a roller made of various rubbers such as natural rubber (NR), urethane rubber, ethylene propylene diene rubber (EPDM), polynorbornene rubber, silicone rubber, chlorinated polyethylene rubber and the like is generally used. It is used for.
However, paper dust generated from the paper is likely to adhere to the outer peripheral surface of the paper feed roller, and the paper feed roller accumulates on the outer peripheral surface while repeatedly contacting the paper, thereby reducing the friction coefficient of the paper feed roller against the paper. As a result, a paper conveyance failure may occur relatively early.

In particular, when paper with a high ash content is used, the paper dust is likely to be generated. Therefore, the accumulation of the paper dust and the resulting paper conveyance failure are likely to occur.
In order to improve the durability, heat aging resistance, etc. of the paper feed roller, ethylene-α-olefin copolymer rubber such as EPM, EPDM and diene rubber may be used in combination as the rubber component forming the paper feed roller ( For example, the use of ozone-resistant rubber such as EPDM and isoprene rubber in combination (for example, see Patent Document 4) has been studied.

  However, according to the inventor's study, the conventional rubber combined system cannot provide a paper feed roller that is unlikely to cause poor paper conveyance when repeatedly brought into contact with paper.

JP 2007-131806 A JP 2007-131808 A JP 2007-154178 A Japanese Patent No. 3947809

  An object of the present invention is to provide a paper feed roller that is less likely to cause a decrease in a coefficient of friction due to accumulation of paper dust and a paper conveyance failure associated therewith, and can maintain good paper feed for a longer period of time. .

According to the inventor's study, the main component of paper dust is a filler contained in paper, and the adhesion of the paper dust is an organic component (classified as aliphatic or aromatic) contained in the paper. Caused by influence. Therefore, the inventor examined a combination of rubber components contained in the rubber composition forming the roller main body with respect to the paper feed roller provided with the roller main body made of a crosslinked product of the rubber composition . That is, by combining a plurality of rubber components, the SP value (kcal1 / 2 / cm3 / 2) of the paper feed roller surface for various organic components contained in aliphatic and aromatic paper is adjusted, and the roller surface of the organic component is adjusted. We studied to suppress the adhesion of paper dust by reducing the adhesion to the paper.

  As a result, ethylene propylene diene rubber (EPDM), isoprene rubber (IR), and styrene butadiene rubber (SBR) are used in combination as rubber components, and the mass ratio of the three rubber components is within a predetermined range. When set, when it is repeatedly brought into contact with paper as is clear from the results of Examples and Comparative Examples described later, it is difficult to cause a decrease in the coefficient of friction due to accumulation of paper dust and the accompanying conveyance failure, which is longer than before. It has been found that it is possible to provide a paper feed roller that can maintain a good paper feed over a wide range.

That is, the present invention is entirely provided with a crosslinked product Tona Ru roller body of the rubber composition, the rubber composition is substantially rubber component, a crosslinking agent, a reinforcing agent or filler, and with consists processing aids, The rubber component comprises three types of ethylene propylene diene rubber (EPDM), isoprene rubber (IR), and styrene butadiene rubber (SBR) , and the three types of rubber components are represented by the formula (1):
R ₁ = M _EPDM / (M _IR + M _SBR ) (1)
[Wherein M _EPDM is EPDM, M _IR is IR, and M _SBR is SBR, respectively. ]
The mass ratio R ₁ represented by the formula is 25/75 or more and 75/25 or less.

In addition, the rubber composition that is the basis of the paper feed roller of the present invention further suppresses the reduction in the coefficient of friction and the accompanying conveyance failure when repeatedly brought into contact with the paper, for a longer period of time. In consideration of providing a paper feed roller capable of maintaining good paper feed, the mass parts of isoprene rubber (IR) and styrene butadiene rubber (SBR) are represented by the formula (2):
M _IR > M _SBR (2)
[In the formula, M _IR represents IR, and M _SBR represents SBR, respectively. ]
Is preferably satisfied.

  Further, the rubber composition further suppresses a decrease in the coefficient of friction when repeatedly contacted with paper and the accompanying conveyance failure, and can maintain a good paper feed for a longer period of time. Is preferably crosslinked by a peroxide crosslinking agent.

  According to the present invention, it is possible to provide a paper feed roller that is less likely to cause a decrease in the coefficient of friction due to accumulation of paper dust and a paper conveyance failure associated therewith, and can maintain good paper feed for a longer period of time. .

It is a perspective view which shows an example of embodiment of the paper feed roller of this invention.

<Rubber composition>
The rubber composition forming the roller body of the paper feed roller of the present invention substantially comprises a rubber component, a crosslinking agent, a reinforcing agent / filler, and a processing aid, and the rubber component includes EPDM, IR, and Formula (1) consisting of three types of SBR and the three types of rubber components:
R ₁ = M _EPDM / (M _IR + M _SBR ) (1)
[Wherein M _EPDM is EPDM, M _IR is IR, and M _SBR is SBR, respectively. ]
In the mass ratio _{R 1} represented is 25/75 or more, characterized in that it is 75/25 or less.

This makes it possible to provide a paper feed roller that is less likely to cause a reduction in the coefficient of friction due to the accumulation of paper dust and associated conveyance failure when repeatedly brought into contact with paper, and that can maintain good paper feed over a longer period of time. can do.
In the present invention, the mass ratio R ₁ of the three kinds of rubber is limited to the above range for the following reason.

That is, when the mass ratio R ₁ is less EPDM be less than the range is reduced weather resistance of the paper feed roller becomes easily or break or crack when used for a long period of time. In addition, since wear resistance is also reduced, it is likely to be worn when repeatedly brought into contact with paper, and the friction coefficient is lowered due to the wear, and paper conveyance is likely to occur.
Meanwhile, since the relative IR and SBR is less in the case where the mass ratio R ₁ is greater than the above range, due to the fact that in combination the rubber content of the three, when obtained by paper and repeated contact, accumulation of paper dust The effect of maintaining good paper feeding over a longer period of time is less likely to occur due to the lowering of the friction coefficient due to, and the accompanying conveyance failure.

The mass ratio R ₁ of the three kinds of rubbers is 45/55 even within the above range in consideration of preventing various problems and maintaining good paper feeding for a long period of time. The above is preferable.
Of the three types of rubber, the mass parts of IR and SBR are represented by formula (2):
M _IR > M _SBR (2)
[In the formula, M _IR represents IR, and M _SBR represents SBR, respectively. ]
Is preferably satisfied. As a result, as will be apparent from the results of Examples and Comparative Examples described later, the decrease in the coefficient of friction when repeatedly contacted with paper and the accompanying conveyance failure are further effectively suppressed, and even longer. A paper feed roller capable of maintaining good paper feed can be provided.

IR and SBR are represented by the formula (3):
R ₂ = M _IR / M _SBR (3)
[In the formula, M _IR represents IR, and M _SBR represents SBR, respectively. ]
Preferably in the mass ratio R ₂ represented it is 3.0 or less.
Of the three types of rubber components, any of various copolymers obtained by copolymerizing ethylene, propylene, and diene can be used as EPDM. Examples of the diene include ethylidene norbornene (ENB) and dicyclopentadiene (DCPD).

As the EPDM, any of so-called oil-extended EPDM extended with an extending oil and non-oil-extended EPDM not extended with an extending oil may be used. Additives such as cross-linking agents to the three rubber components and knead to improve the rubber composition, and improve the workability when molding the rubber composition into the shape of a paper feed roller Considering this, oil-extended EPDM is preferable.
Examples of the ENB-based oil-extended EPDM in which the diene is ENB are, for example, Esprene (registered trademark) 670F manufactured by Sumitomo Chemical Co., Ltd. (rubber: extended oil = 100: 100 (mass ratio)), 671F [rubber: extended Oil = 100: 70 (mass ratio)], Mitsui Chemicals, Inc. Mitsui EPT3042E [rubber content: extended oil = 100: 120 (mass ratio)] and the like.

Examples of the DCPD-based oil-extended EPDM in which the diene is DCPD include, for example, Esprene 400 [rubber content: extended oil = 100: 100 (mass ratio)] manufactured by Sumitomo Chemical Co., Ltd.
As the EPDM, those exemplified above may be used singly or in combination of two or more.
When oil-extended EPDM is used as the EPDM, M _EPDM in the formula (1) is a part by mass of a rubber component (EPDM) contained in the oil-extended EPDM.

As the IR, any of various polymers having a polyisoprene structure can be used.
Examples of the IR include Nipol (registered trademark) IR2200 and IR2200L manufactured by Nippon Zeon Co., Ltd.
As the IR, those exemplified above may be used alone or in combination of two or more.
As the SBR, any of various copolymers obtained by copolymerizing styrene and butadiene by an emulsion polymerization method, a solution polymerization method, or the like can be used.
Further, as the SBR, either a so-called oil-extended SBR extended with an extension oil or a non-oil-extended SBR not extended with an extension oil may be used.

Examples of the oil-extended SBR by the emulsion polymerization method include Nipol 1723 (rubber content: extended oil = 100: 37.5 (mass ratio)) and 1739 (rubber content: extended oil = 100: 37) manufactured by Nippon Zeon Co., Ltd. .5 (mass ratio)], 9548 [rubber content: extended oil = 100: 37.5 (mass ratio)].
Examples of non-oil-extended SBR by the emulsion polymerization method include Nipol 1500 and 1502 manufactured by Nippon Zeon Co., Ltd.

Moreover, as oil-extended SBR by the solution polymerization method, for example, Nipol NS460 [rubber content: extended oil = 100: 37.5 (mass ratio)] manufactured by Nippon Zeon Co., Ltd., NS522 [rubber content: extended oil = 100: 37]. .5 (mass ratio)] and the like.
Furthermore, examples of non-oil-extended SBR by the solution polymerization method include Nipol NS116R, NS210, NS310S, NS616 manufactured by Nippon Zeon Co., Ltd.

As the SBR, those exemplified above may be used singly or in combination of two or more.
When oil-extended SBR is used as SBR, M _SBR in the formulas (1) to (3) is a part by mass of a rubber component (SBR) contained in the oil-extended SBR.
The rubber composition contains a crosslinking agent for crosslinking the rubber component.
As the crosslinking agent, a conventional sulfur vulcanizing system (a combined system of sulfur or a sulfur-containing compound and a vulcanization accelerator, a vulcanization acceleration aid, etc.) may be used. A product cross-linking agent is preferred.

As a result, as will be apparent from the results of Examples and Comparative Examples described later, the decrease in the coefficient of friction when repeatedly contacted with paper and the accompanying conveyance failure are further effectively suppressed, and even longer. A paper feed roller capable of maintaining good paper feed can be provided.
Examples of the peroxide crosslinking agent include benzoyl peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (benzoylperoxy). ) Hexane, di (tert-butylperoxy) diisopropylbenzene, 1,4-bis [(tert-butyl) peroxyisopropyl] benzene, di (tert-butylperoxy) benzoate, tert-butylperoxybenzoate, dicumyl Peroxide, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, ditert-butyl peroxide and 2,5-dimethyl-2,5-di (tert -Butylperoxy) -3-hexene, etc. And the like.

Also the rubber composition, a reinforcing agent or filler such as carbon black, and oil, Ru is contained by appropriately selecting the processing aid such as a plasticizer.
<Paper feed roller>
FIG. 1 is a perspective view showing an example of an embodiment of a paper feed roller 1 of the present invention.
Referring to FIG. 1, a paper feed roller 1 of this example includes a cylindrical roller body 2 made entirely of the rubber composition, and a shaft 4 inserted through a through hole 3 in the center of the roller body 2. Contains. The shaft 4 is made of, for example, metal, ceramic, hard resin, or the like.

The rubber thickness of the roller body 2 is not particularly limited. For example, in the case of a paper feed roller such as an electrostatic copying machine, the rubber thickness is 1 mm or more, 20 mm or less, particularly 2 mm or more. It is preferably about 15 mm or less.
The roller body 2 is formed by molding the rubber composition described above into a cylindrical shape by an arbitrary molding method such as an injection molding method or an extrusion molding method, and then crosslinking the rubber composition by, for example, press crosslinking.

The roller body 2 and the shaft 4 are formed by, for example, forming the outer diameter of the shaft 4 larger than the inner diameter of the through hole 3 of the roller body 2 and press-fitting the shaft 4 into the through hole 3 or bonding the both together They are integrated by adhering with an agent or by vulcanizing and adhering with a vulcanizing adhesive when the roller body 2 is crosslinked.
Further, at any time before and after the integration, the outer peripheral surface 5 of the roller body 2 is further polished to a predetermined surface roughness as necessary, or the outer peripheral surface 5 is subjected to knurling or embossing. Alternatively, both ends of the roller body 2 are cut so that the length of the roller body 2 in the axial direction, that is, the width of the paper feed roller 1 becomes a predetermined value. Thereby, the paper feed roller 1 shown in FIG. 1 is manufactured.

Depending on your sheet conveying roller 1 of the applications, hole 3 may be provided at a position eccentric from the center of the roller body 2. Further, the roller body 2 may have an irregular shape instead of a cylindrical shape, for example, a shape in which a part of the outer peripheral surface 5 is cut out into a flat shape. In order to form the roller body 2 having such an irregular shape, the roller body 2 may be directly molded into the irregular shape by an injection molding method, an extrusion molding method, or the like, or the roller body 2 formed in a cylindrical shape may be formed. The outer peripheral surface 5 may be post-processed to have the irregular shape.

Alternatively, the roller body 2 may be deformed to have the deformed shape by press-fitting a shaft 4 having a deformed shape corresponding to the deformed shape into the through hole 3 of the roller body 2 formed in a cylindrical shape. it can. In this case, polishing, knurling, embossing, etc. of the outer peripheral surface 5 can be performed on the cylindrical roller body 2 before deformation, so that workability can be improved.
The paper feed roller 1 of the present invention is a paper feed roller incorporated in a paper feed mechanism in equipment such as an electrostatic copying machine, a laser beam printer, a plain paper facsimile machine, an ink jet printer, and an automatic cash dispenser (ATM). It can be used as various paper feed rollers such as a transport roller, a platen roller, and a paper discharge roller.

In the following examples and comparative examples, the preparation of rubber compositions, the production of paper feed rollers, and tests were carried out in an environment with a temperature of 23 ± 1 ° C. and a relative humidity of 55 ± 1%, unless otherwise specified.
<Example 1>
Oil-extended EPDM as a rubber component [Esprene 670F manufactured by Sumitomo Chemical Co., Ltd., rubber component: extended oil = 100: 100 (mass ratio)] 60 parts by mass (EPDM as a rubber component is 30 parts by mass), 50 parts by mass of IR [Nipol IR2200 manufactured by Nippon Zeon Co., Ltd.] and 20 parts by mass of SBR [Nipol 1502 manufactured by Nippon Zeon Co., Ltd.] and Dicumylper as a peroxide cross-linking agent 3 parts by mass of oxide [Park Mill (registered trademark) D manufactured by NOF Corporation] and 5 parts by mass of carbon black [HAF, trade name Seast 3 manufactured by Tokai Carbon Co., Ltd.] as a reinforcing agent / filler, A rubber composition was prepared by kneading 20 parts by mass of paraffin oil [Diana (registered trademark) process oil PW-380 manufactured by Idemitsu Kosan Co., Ltd.].

Next, the rubber composition is extruded into a cylindrical shape and then press vulcanized at 160 ° C. for 30 minutes to form a cylindrical body (cot) having an inner diameter φ12.6, an outer diameter φ25, and a length of 60 mm. The cylindrical body was ground to an outer diameter of φ24 using a cylindrical grinder and then cut to a length of 30 mm to form a cylindrical roller body.
Then, a φ14 resin shaft (dedicated resin core) was press-fitted into the through hole of the roller body to manufacture a paper feed roller.

In the rubber composition, the mass ratio R ₁ represented by the formula (1) was 30/70. The parts by weight of IR and SBR will satisfy equation (2), the mass ratio R ₂ of the formula (3) was 2.5.
<Example 2>
The amount of oil-extended EPDM was 100 parts by mass (EPDM as a rubber component was 50 parts by mass), the amount of IR was 30 parts by mass, the amount of SBR was 20 parts by mass, and the amount of paraffin oil was 20 parts by mass. A rubber composition was prepared in the same manner as in Example 1 except that a paper feed roller was produced.

In the rubber composition, the mass ratio R ₁ represented by the formula (1) was 50/50. The parts by weight of IR and SBR will satisfy equation (2), the mass ratio R ₂ of the formula (3) was 1.5.
<Example 3>
The amount of oil-extended EPDM was 100 parts by mass (EPDM as a rubber component was 50 parts by mass), the amount of IR was 20 parts by mass, the amount of SBR was 30 parts by mass, and the amount of paraffin oil was 20 parts by mass. A rubber composition was prepared in the same manner as in Example 1 except that a paper feed roller was produced.

In the rubber composition, the mass ratio R ₁ represented by the formula (1) was 50/50. The parts by weight of IR and SBR are not satisfy the equation (2), the mass ratio R ₂ of the formula (3) was 0.67.
<Example 4>
Implemented except that the amount of oil-extended EPDM was 140 parts by weight (EPDM as rubber was 70 parts by weight), the amount of IR was 20 parts by weight, the amount of SBR was 10 parts by weight, and no paraffin oil was added. A rubber composition was prepared in the same manner as in Example 1 to produce a paper feed roller.

In the rubber composition, the mass ratio R ₁ represented by the formula (1) was 70/30. The parts by weight of IR and SBR will satisfy equation (2), the mass ratio R ₂ of the formula (3) was 2.0.
<Example 5>
In place of the peroxide cross-linking agent, 1 part by mass of powdered sulfur (manufactured by Tsurumi Chemical Co., Ltd.), tetraethylthiuram disulfide (vulcanization accelerator, NOCELLER (registered trademark) TET manufactured by Ouchi Shinsei Chemical Co., Ltd.) ] 2 parts by mass, di-2-benzothiazolyl disulfide [vulcanization accelerating aid, Noxeller DM made by Ouchi Shinsei Chemical Co., Ltd.], stearic acid [trade name made by NOF Corporation Tsubaki] A rubber composition was prepared in the same manner as in Example 4 except that 1 part by mass and 5 parts by mass of zinc oxide 2 types (Mitsui Metal Mining Co., Ltd.) were blended to produce a paper feed roller.

In the rubber composition, the mass ratio R ₁ represented by the formula (1) was 70/30. The parts by weight of IR and SBR will satisfy equation (2), the mass ratio R ₂ of the formula (3) was 2.0.
<Comparative example 1>
The amount of oil-extended EPDM is 40 parts by mass (EPDM as a rubber component is 20 parts by mass), the amount of IR is 50 parts by mass, the amount of SBR is 30 parts by mass, the amount of paraffin oil is 50 parts by mass, and carbon black A rubber composition was prepared in the same manner as in Example 1 except that was not blended to produce a paper feed roller.

In the rubber composition, the mass ratio R ₁ represented by the formula (1) was 20/80. The parts by weight of IR and SBR will satisfy equation (2), the mass ratio R ₂ of the formula (3) was 1.7.
<Comparative example 2>
Implemented except that the amount of oil-extended EPDM was 160 parts by mass (EPDM as rubber was 80 parts by mass), the amount of IR was 10 parts by mass, the amount of SBR was 10 parts by mass, and no paraffin oil was added. A rubber composition was prepared in the same manner as in Example 1 to produce a paper feed roller.

In the rubber composition, the mass ratio R ₁ represented by the formula (1) was 80/20. The parts by weight of IR and SBR are not satisfy the equation (2), the mass ratio R ₂ of the formula (3) was 1.0.
<Comparative Example 3>
200 parts by weight of the same oil-extended EPDM as used in Example 1 (100 parts by weight of EPDM as a rubber component), 1 part by weight of powdered sulfur (manufactured by Tsurumi Chemical Co., Ltd.), tetraethylthiuram disulfide [vulcanization acceleration aid Agent, 2 parts by weight of Nouchira TET made by Ouchi Shinsei Chemical Co., Ltd., di-2-benzothiazolyl disulfide [vulcanization accelerator, Noxeller DM made by Ouchi Shinsei Chemical Co., Ltd.] 1 mass Parts, 1 part by mass of stearic acid [trade name Tsubaki manufactured by NOF Corporation], 5 parts by mass of zinc oxide 2 types [manufactured by Mitsui Kinzoku Mining Co., Ltd.], and carbon black [HAF as a reinforcing agent / filler , 1 part by mass of Tokai Carbon Co., Ltd. trade name Seast 3], 10 parts by mass of silicon oxide [Nipsil (registered trademark) VN3 made by Tosoh Silica Co., Ltd.], calcium carbonate [manufactured by Bihoku Flour Industries BF300], and oxidized chi A rubber composition is obtained by kneading 15 parts by mass of Tan [trade name Kronos KR-380 manufactured by Titanium Industry Co., Ltd.] and 20 parts by mass of paraffin oil [Diana Process Oil PW-380 manufactured by Idemitsu Kosan Co., Ltd.]. Prepared. A paper feed roller was produced in the same manner as in Example 1 except that the rubber composition was used.

<Comparative example 4>
150 parts by mass of the same oil-extended EPDM used in Example 1 (75 parts by mass of EPDM as a rubber component), 25 parts by mass of non-oil-extended EPDM (Esprene 586 manufactured by Sumitomo Chemical Co., Ltd.), 5 parts by mass of carbon black (HAF, trade name 3 manufactured by Tokai Carbon Co., Ltd.) as a filler and dicumyl peroxide (Park Mill D manufactured by NOF Corporation) as a peroxide crosslinking agent A rubber composition was prepared by kneading 5 parts by mass. A paper feed roller was produced in the same manner as in Example 1 except that the rubber composition was used.

<Friction coefficient test and paper passing status evaluation>
While applying a vertical load of 340 gf on a paper 60 mm wide × 210 mm long (Xerox Business 4200 manufactured by Xerox Co., Ltd.) placed on a Teflon (registered trademark) plate, the paper feed roller of each example and comparative example was placed. When the paper feed roller is rotated at a peripheral speed of 105 mm / sec in the pressed state, the conveyance force F applied to the paper is measured using a load cell, and the formula (4):
μ = F / 340 (4)
Was used to determine the friction coefficient μ.

The measurement is performed immediately after the manufacture of the paper feed roller (initial stage), and the paper feed roller is incorporated as a paper feed roller in a laser printer HP Laser Jet 4350n manufactured by Hewlett-Packard Japan Co., Ltd. The same paper (Xerox Business 4200 manufactured by Xerox Corporation). ] After passing 10,000 sheets (after endurance).
In addition, by observing the paper passing status at the time of passing the paper, if the paper feeding failure occurred up to 10,000 sheets, × (paper feeding fault), paper feeding even if 10,000 sheets are passed Those in which no defects occurred were evaluated as ◯ (good paper passing condition).

<Weather resistance test>
The weather resistance of the paper feed roller of each example and comparative example was determined in accordance with the static ozone deterioration test described in Japanese Industrial Standard JIS K6259: 2004 “Vulcanized rubber and thermoplastic rubber-How to determine ozone resistance”. evaluated.
That is, using the same rubber composition prepared in each example and comparative example, a test piece having the dimensions and shape specified in the standard was prepared, and tensile strain (10% elongation) was applied to the test piece. When exposed to ozone under conditions of a temperature of 40 ° C., an ozone concentration of 50 ppm, and a test time of 96 hours, it was confirmed whether or not cracks occurred in the test piece.

And the thing which did not generate | occur | produce a crack was evaluated as (circle) (good weather resistance), and the thing which generate | occur | produced was evaluated as x (bad weather resistance).
The above results are shown in Tables 1 and 2.

From the results of Examples 1 to 5 and Comparative Examples 1 to 4 in both tables, EPDM, IR, and SBR are used in combination as rubber components, and the three rubber components are represented by formula (1). that the mass ratio R ₁ 25/75 or more, 75/25 by forming with the rubber composition containing such a composed or less, a decrease and paper conveyance and defective associated therewith friction coefficient due to the accumulation of paper dust It has been found that a paper feeding roller that can maintain good paper feeding for a longer period than before can be provided because it hardly occurs and has excellent weather resistance.

From the results of Examples 1 to 5, it is preferable that the mass ratio R ₁ is 45/55 or more even within the above range, and that the mass parts of IR and SBR satisfy the formula (2). It has been found that the rubber composition is preferably crosslinked with a peroxide crosslinking agent.

DESCRIPTION OF SYMBOLS 1 Paper feed roller 2 Roller main body 3 Through-hole 4 Shaft 5 Outer peripheral surface

Claims (3)

The roller body is entirely composed of a crosslinked product of a rubber composition, and the rubber composition is substantially composed of a rubber component, a crosslinking agent, a reinforcing agent / filler, and a processing aid. Formula (1) comprising three types of propylene diene rubber (EPDM), isoprene rubber (IR), and styrene butadiene rubber (SBR), and the three types of rubber components:
R ₁ = M _EPDM / (M _IR + M _SBR ) (1)
[Wherein M _EPDM is EPDM, M _IR is IR, and M _SBR is SBR, respectively. ]
In represented by the mass ratio _{R 1} is 25/75 to state, and are 75/25 or less, equation (3):
R ₂ = M _IR / M _SBR (3)
[Wherein, M _IR represents IR, and M _SBR represents part by mass of SBR. ]
In represented by the mass ratio _{R 2} is 0.67 or more, the paper feed roller, characterized in that is 3.0 or less. In the rubber composition, parts by mass of isoprene rubber (IR) and styrene butadiene rubber (SBR) are represented by the formula (2):
M _IR > M _SBR (2)
[In the formula, M _IR represents IR, and M _SBR represents SBR, respectively. ]
The paper feed roller according to claim 1, wherein:   The paper feed roller according to claim 1, wherein the rubber composition is crosslinked by a peroxide crosslinking agent.

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