JP2021147207A - Paper feed roll - Google Patents

Abstract

To provide a paper feed roll in which contamination due to oil adhesion to the paper feed roll is suppressed, a frictional force between a surface of the paper feed roll and a transport paper is high, and frictional force reduction is suppressed over a long period.SOLUTION: In a paper feed roll 10 comprising a shaft body 12 and an elastic layer 14 formed on an outer peripheral surface of the shaft body, the elastic layer a hardened body of a composition containing the following components (A) to (C), a blending amount of the component (B) is 40 to 80 parts by weight to 100 parts by weight of the component (A), and a blending amount of the component (C) is 0.1 to 10 parts by weight to 100 parts by weight of the component (A), and (B) and (A) are combined with each other: (A) ethylene-propylene-diene copolymer; (B) poly-α-olefin of which a kinematic viscosity at 40°C is 30 mm2/s or more and 350 mm2/s or less, and has a reactive group which can chemically reacts with (A); (C) a cross-linking agent.SELECTED DRAWING: Figure 1

Description

The present invention relates to a paper feed roll that is suitably used in electrophotographic equipment such as copiers, printers, and facsimiles that employ an electrophotographic method.

The elastic layer of the paper feed roll is an ethylene-propylene-diene copolymer (hereinafter referred to as "EPDM") having a high molecular weight and a high content ratio of a diene component in order to increase the cross-linking efficiency and ensure sufficient strength and durability. ”) As a rubber component is generally formed into the shape of the roll body and then crosslinked.

As EPDM for the elastic layer, EPDM having a higher molecular weight and a higher content of diene component than before is used. Therefore, in order to impart appropriate flexibility to the roller body and increase the coefficient of friction against paper, for example, in Patent Document 1. Discloses in the Examples a rubber composition containing a large amount of oil of 50 parts by weight per 100 parts by weight of EPDM.

Further, Patent Document 2 discloses a technique in which liquid EPDM is added instead of oil to chemically react with EPDM during a crosslinking reaction and be incorporated into a cured product to suppress bleeding.

Japanese Unexamined Patent Publication No. 2004-010322 Japanese Unexamined Patent Publication No. 2011-256347

However, a paper feed roll using a rubber composition containing a large amount of oil of 50 parts by weight per 100 parts by weight of EPDM suppresses contamination of the conveyed paper due to oil bleeding out and a decrease in the friction coefficient of the paper feed roll after long-term use. Can't.

Further, by adding liquid EPDM instead of oil, when it chemically reacts with EPDM and is taken into the cured product, bleeding out from the elastic layer of the paper feed roll can be suppressed, but the surface of the paper feed roll It is not possible to solve the problem that the frictional force with the conveying paper is low.

The problem to be solved by the present invention is to suppress contamination due to the adhesion of the composition of the elastic layer of the paper feed roll to the transport paper, to have a high frictional force between the surface of the paper feed roll and the transport paper, and for a long period of time. The purpose of the present invention is to provide a paper feed roll that suppresses a decrease in frictional force.

In order to solve the above problems, the paper feed roll according to the present invention is a paper feed roll including a shaft body and an elastic layer formed on the outer peripheral surface of the shaft body.
The elastic layer is a cured product of a composition containing the following components (A) to (C).
The blending amount of the following component (B) is 40 parts by weight to 80 parts by weight with respect to 100 parts by weight of the following component (A), and the blending amount of the following component (C) is based on 100 parts by weight of the following component (A). 0.1 parts by weight to 10 parts by weight and
A paper feed roll characterized in that the following (B) and the following (A) are combined.
(A) Ethylene-propylene-diene copolymer.
(B) A poly-α-olefin having a kinematic viscosity at 40 ° C. of 30 mm ² / s or more and 350 mm ² / s or less and having a reactive group capable of chemically reacting with the above (A).
(C) Crosslinking agent.

According to the paper feed roll according to the present invention, it is a cured product of the composition containing the following (A) to (C).
(A) Ethylene-propylene-diene copolymer.
(B) A poly-α-olefin having a kinematic viscosity at 40 ° C. of 30 mm ² / s or more and 350 mm ² / s or less and having a reactive group capable of chemically reacting with the above (A).
(C) Cross-linking agent The blending amount of the component (B) is 40 parts by weight to 80 parts by weight with respect to 100 parts by weight of the component (A), and the blending amount of the component (C) is 100 parts by weight of the component (A). It is 0.1 part by weight to 10 parts by weight with respect to the part by weight, and the combination of (B) and (A) causes the components of the elastic layer composition to adhere to the transport paper. It is possible to provide a paper feed roll that suppresses contamination, has a high frictional force between the surface of the paper feed roll and the conveyed paper, and suppresses a decrease in the frictional force for a long period of time.

When the (A) is an ethylene-propylene-diene copolymer, the paper feed roll has flexibility and the production cost can be reduced.
Further, when the kinematic viscosity of (B) at 40 ° C. is 30 mm ² / s or more and 350 mm ² / s or less, the frictional force between the surface of the paper feed roll and the conveyed paper becomes high.
Further, by binding a poly-α-olefin having a reactive group capable of chemically reacting the (B) with the (A) by a chemical reaction according to the (C), the component (B) is said. Since it is fixed to the component (A), the bleed-out of the (B) can be suppressed, the contamination due to the adhesion of the (B) to the transport paper is suppressed, and the frictional force between the surface of the paper feed roll and the transport paper is high. Moreover, it is possible to obtain a paper feed roll in which a decrease in frictional force is suppressed for a long period of time.

It is the schematic of the paper feed roll of this invention. It is a figure which shows the measuring method of the friction coefficient of a paper feed roll.

Hereinafter, the present invention will be described in detail. The paper feed roll according to the present invention is not particularly limited in shape and layer structure as long as it is suitably used in an electrophotographic device such as a copying machine, a printer, or a facsimile that employs an electrophotographic method.

The paper feed roll according to the present invention will be described in detail. FIG. 1 is a schematic external view of a paper feed roll for an electrophotographic apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a method of measuring the friction coefficient of the paper feed roll.

The paper feed roll 10 includes a shaft body 12 and an elastic body layer 14 formed on the outer periphery of the shaft body 12. The elastic layer 14 is a layer that serves as a base for the paper feed roll 10.

The elastic layer 14 is a cured product of a composition containing the following (A) to (C).
(A) Ethylene-propylene-diene copolymer.
(B) A poly-α-olefin having a kinematic viscosity at 40 ° C. of 30 mm ² / s or more and 350 mm ² / s or less and having a reactive group capable of chemically reacting with the above (A).
(Hereinafter, it may be simply referred to as "modified poly-α-olefin".)
(C) Crosslinking agent

The EPDM (A) preferably contains an ethylene component unit of 52% by mass or more and 70% by mass or less. If the content of the ethylene component unit is less than 52% by mass, the wear resistance of the elastic layer of the paper feed roll may be lowered. On the other hand, if the content of the ethylene unit exceeds 70% by mass, it may be difficult to secure the required friction coefficient after the paper passing test.

The EPDM (A) preferably contains a diene component of 2.8% by mass or more and 5.5% by mass or less. If the content of the diene component is less than 2.8% by mass, when cross-linking with sulfur, there are few components that chemically react, the hardness and elastic modulus are lowered, and the wear resistance is lowered and the compressive permanent strain property is lowered. May be invited. On the other hand, if the content of the diene component exceeds 5.5% by mass, it becomes difficult to secure the required friction coefficient after the paper passing test. From this point of view, the content of the diene component is more preferably 2.8% by mass or more and 4.8% by mass or less. Here, the diene component contained in EPDM is not particularly limited, but may be, for example, ethylidene-norbornene, 1,4-hexadiene, dicyclopentadiene, etc., and ethylidene-norbornene is preferable.

The EPDM (A) may contain two or more types of EPDM. When the above (A) contains two or more types of EPDM, the content of the ethylene component unit is an average value calculated from the content of the ethylene component of various EPDMs and the content ratio of various EPDMs.

The modified poly-α-olefin (B) has a kinematic viscosity at 40 ° C. of 30 mm ² / s or more and 350 mm ² / s or less. If the kinematic viscosity is ^{less than 30 mm 2} / s, the molecular weight is small, so that the phase separation from the (A) is easy, and the (B) and the (A) are bonded by a chemical reaction via the (C). It becomes difficult, and the unreacted (B) may cause bleeding, resulting in a decrease in friction coefficient or paper contamination. If the kinematic viscosity ^{exceeds 350 mm 2} / s, it becomes difficult to secure the required friction coefficient after the paper passing test.
From this point of view, the kinematic viscosity of the modified poly-α-olefin (B) ^{is more preferably 30 mm 2} / s or more and 120 mm ² / s or less. A more preferable range is 30 mm ² / s or more and 80 mm ² / s or less.

Examples of the α-olefin used in the synthesis of the modified poly-α-olefin (B) include α-olefins having 2 to 25 carbon atoms, and specifically, ethylene, propylene, 1-butene, 1-pentene, 1 -Linear chains such as hexene, 1-hexene, 1-octene, 1-nonen, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-octadecene Examples thereof include α-olefins.

Non-conjugated diene is exemplified as a reactive group capable of chemically reacting with the (A) EPDM of the (B) modified poly-α-olefin, and 1,4-hexadiene, methylene-norbornene, dicyclo-pentadiene, ethylene. -Norbornene, dicyclo-pentadiene and the like can be mentioned.

A component having a reactive group capable of chemically reacting with the α-olefin used for the synthesis of the (B) modified poly-α-olefin and the (A) EPDM of the (B) modified poly-α-olefin. By the copolymerization, the above-mentioned (B) modified poly-α-olefin can be obtained.
These α-olefins and A) components having a reactive group capable of chemically reacting with EPDM are used alone or in combination of two or more.

The α-olefin used in the synthesis of the modified poly-α-olefin (B) is preferably 1-octene from the viewpoint of ensuring the friction coefficient.
Ethylene-norbornene is preferable as the component of the (B) modified poly-α-olefin having a reactive group capable of chemically reacting with the (A) EPDM from the viewpoint of ensuring the durability of the friction coefficient.

In the present invention, the modified poly-α-olefin polymerization method is not particularly limited and various known methods can be adopted. A solvent polymerization method using an inert hydrocarbon as a medium, a massive polymerization method using a liquid olefin as a medium, and the like. Any method of the vapor phase polymerization method in which a liquid medium is substantially not present can be adopted.
For example, there is a method of copolymerizing a transition metal compound such as vanadium, zirconium, titanium, hafnium in the presence of a catalyst composed of an organoaluminum compound (organoaluminium oxy compound) and / or an ionized ionic compound. A metallocene catalyst using a transition metal compound such as zirconium, titanium, or hafnium is preferable because the amount of 2,1-bonds formed from two or more consecutive propylene monomers is reduced and the low temperature characteristics of the thermoplastic elastomer are improved. .. Such a method is described in, for example, International Publication No. 2000/34420, Japanese Patent Application Laid-Open No. 62-121710, International Publication No. 2004/29062, Japanese Patent Application Laid-Open No. 2004-175707, International Publication No. 2001/27124, and the like. ..

The rubber composition of the present embodiment may contain two or more of the above-mentioned (B) modified poly-α-olefins. When the composition contains two or more of the above (B), the kinematic viscosity at 40 ° C. is evaluated as an average value calculated from the various kinematic viscosities of the (B) and the various content ratios of the (B). When two or more kinds are used in combination, one having a kinematic viscosity within the above range and one having a kinematic viscosity outside the above range may be mixed.

The molecular weight distribution (Mw / Mn) of the modified poly-α-olefin (B) used in the present invention is preferably 1.0 to 3.0, more preferably 1.4 to 2.5. When the molecular weight distribution is wide (Mw / Mn is large), oozing is likely to occur, and a large amount of low molecular weight components that deteriorate the bleed-out property and high molecular weight components that may reduce the softening effect and the processability improving effect are contained. This is not preferable. The molecular weight distribution (Mw / Mn) is determined as a ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) determined by gel permeation chromatography (GPC).

The modified poly-α-olefin (B) used in the present invention has a glass transition temperature (Tg) preferably in the range of −90 to −65 ° C., more preferably in the range of −80 to −65 ° C. If the glass transition temperature (Tg) exceeds −65 ° C., the flexibility at low temperature decreases, which is not preferable. When the (B) modified poly-α-olefin having a glass transition temperature (Tg) of −90 ° C. to −65 ° C. is used, the effect of lowering the glass transition temperature (Tg) of the obtained thermoplastic elastomer is practically sufficient. Is. On the other hand, when the glass transition temperature (Tg) is lower than −90 ° C., the molecular weight is lowered and the volatility is increased, which is not preferable.

In the present invention, the glass transition temperature (Tg) of the (B) modified poly-α-olefin is measured by differential scanning calorimetry (DSC) (JIS-K7121).

Further, the modified poly-α-olefin (B) may be graft-modified with a reactive group capable of chemically reacting with the (A), or may be further secondarily modified. For example, as the graft modification, the method described in JP-A-61-126120, Japanese Patent No. 2593264, etc., and as the secondary modification, the method described in JP-A-2008-508402, etc. Can be mentioned.

The cross-linking agent (C) is inexpensive and easily available, and sulfur is preferable from the viewpoint of wear resistance, cross-linking strength, etc. of the vulcanized rubber composition. In addition to sulfur, sulfur-based organic compounds such as tetraalkylthiraum disulfide, metal compounds such as magnesium oxide, organic peroxides, and resin cross-linking agents can be used.

When sulfur is used as the (C) cross-linking agent, the non-conjugated diene of (A) EPDM and the reactive group (non-conjugated diene, etc.) of the (B) modified poly-α-olefin are sulfide-bonded and cured. The body is obtained.
When an organic peroxide is used as the (C) cross-linking agent, the terminal of (A) EPDM, an ethylene unit, a non-conjugated diene, and a reactive group (non-conjugated diene, etc.) of the (B) modified poly-α-olefin, etc. ) And combined to obtain a cured product.

The blending amount of the (B) modified poly-α-olefin is 40 parts by weight to 80 parts by weight with respect to 100 parts by weight of the (A) EPDM component. When the blending amount of the modified poly-α-olefin (B) is less than 40 parts by weight, the frictional force with the paper to be conveyed on the surface of the paper feed roll and the frictional force over a long period of time are reduced.
When the blending amount of the modified poly-α-olefin (B) is more than 80 parts by weight, contamination due to adhesion of the elastic layer composition component of the paper feed roll to the transport paper cannot be sufficiently suppressed.
From this point of view, the blending amount of the (B) modified poly-α-olefin is more preferably 50 parts by weight to 70 parts by weight with respect to 100 parts by weight of the (A) EPDM component. A more preferable range is 55 parts by weight to 65 parts by weight.

The blending amount of the (C) cross-linking agent is 0.1 part by weight to 10 parts by weight with respect to 100 parts by weight of the (A) EPDM component.
If the blending amount of the (C) cross-linking agent is less than 0.1 parts by weight, the wear resistance of the elastic layer of the paper feed roll may be lowered and the compression set may be lowered. If the blending amount of the (C) cross-linking agent exceeds 10 parts by weight, the hardness increases, the friction coefficient retention property decreases, and it may be difficult to secure the friction coefficient required for the paper passing test.
From this point of view, when the (C) cross-linking agent is sulfur, the blending amount is more preferably 0.5 parts by weight to 5 parts by weight with respect to 100 parts by weight of the (A) EPDM component. A more preferable range is 1 part by weight to 3 parts by weight.
From this point of view, when the (C) cross-linking agent is an organic peroxide, the blending amount may be 0.1 part by weight to 5 parts by weight with respect to 100 parts by weight of the (A) EPDM component. , More preferred. A more preferable range is 0.5 parts by weight to 3 parts by weight.

When the composition of the present embodiment contains sulfur as a cross-linking agent, the composition preferably contains a vulcanization accelerator. The vulcanization accelerator is not particularly limited, and thiazoles such as dibenzothiazyl disulfide, sulfenamides such as N-cyclohexyl-2-benzothiazolesulfenamide, thiraums such as tetramethyltiraum disulfide, or dimethyl. Any dithiocarbamate such as zinc dithiocarbamate may be used. These materials may be used alone, or two or more of these materials may be used in combination. The blending amount of the vulcanization accelerator is not particularly limited and may be appropriately set.

The composition of the present embodiment may contain a vulcanization accelerating aid. As the sulfide accelerating aid, an appropriate one can be selected by a cross-linking system from known ones such as metal oxides such as zinc oxide, fatty acids such as stearic acid or oleic acid, and fatty acid metal compounds such as zinc stearate. can. The blending amount of the vulcanization accelerating aid is not particularly limited and may be appropriately set.

The composition of the present embodiment may contain an inhibitor of scorch. Examples of the scorch inhibitor include known maleic anhydride, thioimine compounds, sulfenamide compounds, sulfonamide compounds and the like. The blending amount of the scorch inhibitor is not particularly limited and may be set as appropriate, but it is preferably 3 parts by weight or less with respect to 100 parts by weight of the polymer component.

The composition of the present embodiment may contain a filler if necessary. The filler is not particularly limited, but may be carbon black, silica, calcium carbonate, magnesium carbonate, aluminum hydroxide, clay, talc, diatomaceous earth, mica, wood chips, or cork, and may be straw, bamboo, metal, glass. , Or a fiber made of a polymer. These may be used alone or in combination.

The blending amount of the filler is not particularly limited, but the blending amount is preferably 10 parts by weight or less, and more preferably 5 parts by weight or less with respect to 100 parts by weight of the component (A). If the blending amount of the filler exceeds 10 parts by weight, the hardness increases and it becomes difficult to obtain a high friction coefficient suitable for the paper feed roll.

The composition of the present embodiment may contain an antiaging agent, if necessary. In this case, examples of the anti-aging agent used include amine-based anti-aging agents, phenol-based anti-aging agents, and sulfur-based anti-aging agents. The amount of the antiaging agent to be blended is not particularly limited.

The composition of the present embodiment may contain a conductive agent such as an ionic conductive agent and an electronic conductive agent. Examples of the ionic conductive agent include a quaternary ammonium salt, a quaternary phosphonium salt, a borate, and a surfactant. Examples of the electronic conductive agent include conductive oxides such as carbon black, graphite, conductive titanium oxide, conductive zinc oxide, and conductive tin oxide. Those listed on the surface layer can be preferably used.

Various additives may be appropriately added to the composition of the present embodiment, if necessary. Examples of additives include lubricants, antioxidants, light stabilizers, viscosity modifiers, processing aids, flame retardants, plasticizers, foaming agents, dispersants, defoamers, pigments, mold release agents and the like. ..

The cured product of the composition of the present embodiment can be adjusted to a predetermined volume resistivity by adjusting the blending amount of the ionic conductive agent, the blending amount of the electron conductive agent, and the like. The volume resistivity of the elastic layer may be appropriately set in the range of ^{10 2} to 10 ¹⁰ Ω · cm, 10 ³ to 10 ⁹ Ω · cm, 10 ⁴ to 10 ^{8 Ω · cm, and the like.}

The thickness of the cured product of the composition of the present embodiment is not particularly limited, and may be appropriately set within the range of 0.1 to 10 mm depending on the intended use. The elastic layer may be a foam or a non-foam.

The paper feed roll of the present embodiment can be manufactured, for example, as follows.
After the desired formulation, knead at 70 ° C. to 100 ° C. for 3 to 10 minutes using a known rubber kneading device such as an open roll, a Banbury mixer, or a kneader, and then knead at 150 ° C. to 180 ° C. for 10 minutes to 30 minutes. It can be manufactured by performing minute press vulcanization to prepare a cot, polishing the cot with a cylindrical grinding machine to obtain a desired outer diameter, and cutting the cot to a desired length.

The shaft body is not particularly limited as long as it has conductivity. Specifically, a metal core such as iron, stainless steel, and aluminum, a core metal made of a hollow body, and the like can be exemplified. If necessary, an adhesive, a primer, or the like may be applied to the surface of the shaft body. That is, the elastic body layer may be adhered to the shaft body via the adhesive layer (primer layer). The adhesive, primer, etc. may be made conductive as needed.

The configuration of the paper feed roll 10 according to the present invention is not limited to the configuration shown in FIG. For example, the paper feed roll 10 shown in FIG. 1 may have a configuration in which another elastic body layer is provided between the shaft body 12 and the elastic body layer. Further, for example, the paper feed roll 10 shown in FIG. 1 may have a configuration in which another elastic body layer is provided on the surface of the elastic body layer.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

Examples 1 to 5 and Comparative Examples 1 to 6 were kneaded at the required temperatures at the respective blending ratios shown in Table 1 below, press vulcanized at 170 ° C. for 20 minutes, and had an inner diameter of φ9 mm and an outer diameter of 9 mm. A cot having a diameter of 21 mm and a length of 38 mm was prepared. This cot was polished to an outer diameter of φ20 mm with a cylindrical grinding machine and cut to a length of 10 mm. This cut rubber molded body was fitted into a special core metal to prepare paper feed rollers of Examples 1 to 5 and Comparative Examples 1 to 6, and used in the following measurements and observations.

The unit of the compounding ingredient in Table 1 is a part by weight. Moreover, as EPDM rubber, the weight part of the rubber content is described.

As the compounding ingredients in Table 1, those having each product name of each of the following companies were used.
・ EPDM: Sumitomo Chemical's "Esprene 586"
-Stearic acid: "Lunac S-30" manufactured by Electrochemical Co., Ltd.
-Zinc oxide: "Zinc Oxide No. 1" manufactured by Shodo Chemical Co., Ltd.
-Silica: "Nipsil VN3" manufactured by Tosoh Silica
・ Carbon black: Tokai Carbon "Seast 3"
-Modified poly-α-olefin A: "Lucant HC-10" manufactured by Mitsui Chemicals (40 ° C. kinematic viscosity 60 mm ² / s, non-conjugated diene modification)
-Modified poly-α-olefin B: "Lucant HC-20" manufactured by Mitsui Chemicals (40 ° C kinematic viscosity 100 mm ² / s, non-conjugated diene modification)
-Modified poly-α-olefin C: "Lucant HC-40" manufactured by Mitsui Chemicals (40 ° C kinematic viscosity 400 mm ² / s, non-conjugated diene modification)
-Modified poly-α-olefin D: "Lucant HC-100" manufactured by Mitsui Chemicals (40 ° C. kinematic viscosity 1300 mm ² / s, non-conjugated diene modification)
-Non-denatured poly-α-olefin A: "Synfluid PAO4" manufactured by Cheveron Phillips (40 ° C. kinematic viscosity 17 mm ² / s)
-Non-denatured poly-α-olefin B: "Synfluid PAO9" manufactured by Cheveron Phillips (40 ° C. kinematic viscosity 53 mm ² / s)
・ Organic peroxide: NOF Corporation "Park Mill D"
・ Powdered sulfur: Tsurumi Chemical "Powdered sulfur"
-Vulcanization accelerator DM: "Noxeller DM" (dibenzothiazil disulfide) manufactured by Ouchi Shinko Kagaku Co., Ltd.
-Vulcanization accelerator TET: "Noxeller TET" (tetraethylthiuram disulfide) manufactured by Ouchi Shinko Kagaku Co., Ltd.

The following measurements and evaluations were performed on the paper feed rolls of each Example and each Comparative Example produced as described above. The results are shown in Table 1 above. The hardness (JIS A hardness (JIS K6253 spring type measurement method)) was also measured.

(Measurement of coefficient of friction)
The coefficient of friction was measured by the following method shown in FIG. That is, a 60 mm × 210 mm size paper 24 (P paper manufactured by Fuji Xerox Co., Ltd.) connected to the load cell 25 is sandwiched between the paper feed roll 21 and the polytetrafluoroethylene plate 23, as shown by the arrows in FIG. A vertical load W (W = 250 gf) was applied to the rotating shaft 22 of the paper feed roll 21, and the paper feed roll 21 was pressed against the polytetrafluoroethylene plate 23. Next, under the conditions of a temperature of 23 ° C. and a humidity of 55%, the paper feed roll 21 was rotated in the direction indicated by the solid arrow a in FIG. 2 at a peripheral speed of 300 mm / sec. Before and after the paper is passed, the transport force F (gf) of the paper 24 generated in the direction indicated by the arrow in FIG. 2 is measured by the load cell 25, and the F (gf) and the load W (W = 250 gf) are as follows. The coefficient of friction μ was obtained from Equation 1. The initial friction coefficient was “⊚” for 1.5 or more, “〇” for 1.0 or more and less than 1.5, and “x” for less than 1.0.

(Formula 1)
μ = F (gf) / W (gf)

(Measurement of friction coefficient after passing 50,000 sheets)
The paper feed roll was incorporated into a commercially available copying machine having an FRR type paper feeding system, and after passing 50,000 sheets of commercially available PPC paper, the friction coefficient was measured by the above-mentioned friction coefficient measuring method. The coefficient of friction after passing 50,000 sheets was "⊚" for 1.0 or more, "○" for less than 1.0, and "x" for less than 0.5.

(Paper stain)
In the 50,000-sheet passing test, if the passed paper is not stained with the naked eye, it is "◎", if it is confirmed in one place, it is "○", and if it is confirmed in two or more places, it is "◎". × ”.

(evaluation)
Comprehensive evaluation is performed based on the results of the coefficient of friction, etc., and those judged to be excellent as paper feed rolls are judged to be "◎", those judged to be at an acceptable level are judged to be "○", and those judged to be inferior. "X" is shown in the "Evaluation" column in Table 1.

As shown in Table 1, the paper feed rolls of Examples 1 to 5 contain 1 part by weight of stearic acid, 5 parts by weight of zinc oxide, 5 parts by weight of silica, and 0 parts by weight of carbon black with respect to 100 parts by weight of EPDM. .25 parts by weight and 40 to 80 parts by weight of modified poly α-olefin were blended, and in Examples 1, 2, 4 and 5, 1.5 parts by weight of powdered sulfur and 1 part by weight of vulcanization accelerator DM were added. The paper feed roll of the present invention comprises a composition containing 2 parts by weight of the vulcanization accelerator TET and 2 parts by weight of an organic peroxide. The paper feed rollers of Examples 1, 3 and 5 had an initial friction coefficient of 1.5 or more, which was a good value. Further, the initial friction coefficient of the paper feed rolls of Examples 2 and 4 was 1.0 or more, which was an allowable level.
Further, in Examples 1, 3 and 5, the friction coefficient after passing 50,000 sheets was 1.0 or more, which was a good value, and in Examples 2 and 4, the friction coefficient after passing 50,000 sheets was high. At 0.5 and above, it was an acceptable level.
Further, in Examples 1 and 4, stains were not confirmed with the naked eye on the passed paper, which was good, and further, only one stain was confirmed in Examples 2, 3 and 5, which was an acceptable level. In addition, a comprehensive evaluation was performed as a paper feed roll, and it was judged that Example 1 was excellent as a paper feed roll, and that Examples 2 to 5 were judged to be at an acceptable level.

On the other hand, Comparative Examples 1 and 2 differ only in the composition of the modified poly-α-olefin (B) as compared with the formulation of Example 1, and are outside the scope of the present invention. Comparative Examples 3 and 4 contain an unmodified poly-α-olefin instead of the modified poly-α-olefin (B), which is outside the scope of the present invention. Comparative Examples 5 and 6 differ only in the blending amount of the (B) modified poly-α-olefin, which is outside the scope of the present invention. That is, in Comparative Examples 1 and 2, since the kinematic viscosity of the modified poly-α-olefin (B) at 40 ° C. is higher than the upper limit value, the initial friction coefficient is less than 1.0, and the friction after passing 50,000 sheets. The coefficient was less than 0.5. Further, in Comparative Examples 3 and 4, the non-modified poly-α-olefin does not have a reactive group capable of chemically reacting with the EPDM (A), and the coefficient of friction after passing 50,000 sheets is high. It was less than 0.5, and two or more stains were confirmed. Further, in Comparative Example 5, it is below the lower limit of the blending amount of the (B) modified poly-α-olefin, the initial friction coefficient is less than 1.0, and the friction coefficient after passing 50,000 sheets is 0. It was less than 5. In Comparative Example 6, the upper limit of the blending amount of the modified poly-α-olefin was exceeded, and two or more stains were confirmed. From the above, it was judged that Comparative Examples 1 to 6 were inferior as the paper feed roll.

As is clear from the above description, according to the paper feed roll according to the present invention, (B) the kinematic viscosity at 40 ° C. is 30 mm ² / s or more and 350 mm ² / s or less, and chemically reacts with the above (A). A poly-α-olefin having a capable reactive group is bonded to the (A) ethylene-propylene-diene copolymer, and the blending amount of the (B) component is 100 parts by weight of the (A) component. Since the amount of the component (C) is 40 to 80 parts by weight and the amount of the component (C) is 0.1 to 10 parts by weight with respect to 100 parts by weight of the component (A). Contamination due to oil adhesion of the feed roll to the transport paper is suppressed, the frictional force with the transport paper on the surface of the paper feed roll is high, and a decrease in the frictional force is suppressed over a long period of time.

Therefore, the paper feed performance is stable for a long period of time from the beginning of use to after repeated use, and the trouble of repair and maintenance can be saved. Therefore, it is possible to improve the durability of the paper feed roller used in the OA equipment such as a laser printer, an electrostatic copier, and a plain paper facsimile machine, and the paper feed mechanism such as an automated teller machine (ATM).

10 Paper feed roll 12 Shaft body 14 Elastic layer 21 Elastic layer 22 Shaft body 23 Base plate 24 Paper 25 Load cell F Friction force W Load a Rotation direction

Claims (3)

A paper feed roll including a shaft body and an elastic layer formed on the outer peripheral surface of the shaft body.
The elastic layer is a cured product of a composition containing the following components (A) to (C).
The blending amount of the following component (B) is 40 parts by weight to 80 parts by weight with respect to 100 parts by weight of the following component (A), and the blending amount of the following component (C) is based on 100 parts by weight of the component (A). 0.1 parts by weight to 10 parts by weight and
A paper feed roll characterized in that the following (B) and the following (A) are bonded cured products.
(A) Ethylene-propylene-diene copolymer.
(B) A poly-α-olefin having a kinematic viscosity at 40 ° C. of 30 mm ² / s or more and 350 mm ² / s or less and having a reactive group capable of chemically reacting with the above (A).
(C) Crosslinking agent.
The paper feed roll according to (B), wherein the kinematic viscosity at 40 ° C. is 30 mm ² / s or more and 80 mm ^{2 / s or less.}
A paper feed roll characterized in that the (C) cross-linking agent is sulfur.

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