JP2014144870A - Paper feed roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feed roller 1 capable of maintaining satisfactory paper feed for long period of time since initial physical properties of an inner layer 6 and an outer layer 8 constituting a cylindrical roller body 3 are set to be preset design values and an intermediate layer 7 reliably prevents movement of components between the two layers, so that the physical properties of the two layers are not significantly changed from the initial ones and components moved from the inner layer to the outer layer are not bled or do not bloom at an outer peripheral surface of the outer layer.SOLUTION: The intermediate layer 7 is formed on an outer peripheral surface of the inner layer 6 by winding a non-porous and continuous plastic film 9 cylindrically.

Description

  The present invention relates to a paper feed roller used for paper feed in an image forming apparatus such as an electrostatic copying machine or various printers.

For example, there are paper feeding mechanisms in electrostatic copying machines, laser printers, plain paper facsimile machines, and complex machines of these, image forming apparatuses such as ink jet printers, and automatic cash dispensers (ATMs). Various paper feed rollers are incorporated.
Examples of the paper feed roller include a paper feed roller, a transport roller, a platen roller, a paper discharge roller, and the like, which rotate while contacting paper (including a plastic film, etc.) and convey the paper by friction. It is done.

Conventionally, as the paper feed roller, for example, a single-layer roller body integrally formed in a cylindrical shape with an elastic material such as a rubber cross-linked material, and its outer peripheral surface is a contact surface with paper, and the center of the roller body A shaft provided with a shaft inserted into the through hole has been generally used.
However, when the number of sheets passed through a single-layer roller body increases, the coefficient of friction of the outer peripheral surface with respect to the paper decreases, resulting in poor paper conveyance, or sound generated when the paper slides on the outer peripheral surface. There was a problem that it was easy to produce.

Therefore, in order to suppress the occurrence of these problems, in Patent Document 1, the roller body has a three-layer structure including a cylindrical inner layer, an intermediate layer, and an outer layer, and each of the layers is non-porous. It is considered that the inner layer is made of an elastomer having a type A durometer hardness of 10 or less and the outer layer is made of an elastomer having a type A durometer hardness of 25 to 60.
That is, by forming the inner layer with the soft elastomer as described above, the outer layer is made harder than the inner layer while ensuring the contact area between the outer peripheral surface of the roller body and the paper and suppressing the reduction of the friction coefficient. It is possible to balance the wear resistance and friction coefficient of the roller body, and to cause poor paper conveyance and squealing over a longer period of time compared to conventional single-layer structures. It is thought that it can be prevented.

The intermediate layer is formed in order to prevent components from moving between the inner layer and the outer layer.
That is, cross-linking components such as cross-linking agents and accelerators contained in the inner layer, and additive components such as plasticizers and oils move to the outer layer side. Conversely, these components contained in the outer layer move to the inner layer side. As a result, the physical properties such as hardness and elasticity of each layer are prevented from greatly fluctuating from a preset range, and in particular, components that have moved from the inner layer to the outer layer bleed on the outer peripheral surface of the outer layer. In order to prevent or bloom, an intermediate layer is provided between the inner layer and the outer layer.

  The intermediate layer is formed by coating a coating material containing a resin such as polyurethane on the outer peripheral surface of the inner layer. Further, for example, the inner layer in which the intermediate layer is formed is press-fitted into the through hole of the outer layer whose inner diameter is slightly smaller than the outer diameter of the inner layer, so that an adhesive or the like is provided between the intermediate layer and the outer layer. A roller body having a three-layer structure in which the inner layer, the intermediate layer, and the outer layer are integrated is formed.

JP 2006-111401 A

However, when the intermediate layer is formed by coating the outer peripheral surface of the inner layer with a coating material as described above, the coating material is repelled by the outer peripheral surface of the inner layer, so that a pinhole or the like is formed in the formed intermediate layer. Prone to defects.
Further, since the intermediate layer has a lower film strength than, for example, a continuous plastic film, the intermediate layer is easily damaged or peeled when the inner layer on which the intermediate layer is formed is pressed into the through hole of the outer layer. .

Therefore, in the conventional intermediate layer, it may be difficult to completely separate the inner layer and the outer layer to prevent the movement of components. That is, when defects such as pinholes, scratches, and peeling occur, the components move from the inner layer to the outer layer or vice versa through these defect portions.
Moreover, it is difficult to find these defects after assembling the roller body by press-fitting as described above, and if the paper feed roller is used overlooking the occurrence of defects, Due to the change in the physical properties of the inner layer and the outer layer due to the movement of, the friction coefficient is greatly reduced or squeal is likely to occur. In addition, the component that has moved from the inner layer to the outer layer may bleed or bloom on the outer peripheral surface of the outer layer.

The cited document 1 describes that instead of applying the coating material, an inner layer is formed by covering the inner layer with a heat-shrinkable tube and then heat-shrinking by heating so as to adhere to the outer peripheral surface of the inner layer. Has been.
Such a heat-shrinkable tube is basically made of a non-porous and continuous plastic film, so that the defect is not easily generated.

However, when the intermediate layer is formed by heat shrinking the heat-shrinkable tube as described above, stress is applied to the inner layer from the intermediate layer, so that the physical properties such as hardness and elasticity of the inner layer greatly deviate from the design values. There is a fear. For example, the hardness of the inner layer tends to be harder than the design value when the stress is applied.
Moreover, it is difficult to predict how much stress is applied from the intermediate layer to the inner layer.

If the outer diameter of the inner layer, the inner diameter of the heat-shrinkable tube that forms the intermediate layer, the amount of heat shrinkage, and the like vary, the stress applied from the intermediate layer to the inner layer varies greatly.
Therefore, it is practically impossible to predict the stress applied to the inner layer from the intermediate layer and to prepare the material for the inner layer so that the physical properties of the inner layer after compression become a predetermined value. It is.

  The object of the present invention is that the initial physical properties of the inner layer and the outer layer constituting the cylindrical roller body are set to preset design values, and the intermediate layer ensures that the components move between the two layers. As a result, the physical properties of the two layers largely fluctuate from the initial stage, and components that have moved from the inner layer to the outer layer do not bleed or bloom on the outer peripheral surface of the outer layer. It is to provide a paper feed roller that can be maintained.

The present invention is a paper feed roller provided with a cylindrical roller body, wherein the roller body has a three-layer structure each including a cylindrical inner layer, an intermediate layer, and an outer layer, A non-porous and continuous plastic film is formed in a cylindrical shape on the outer peripheral surface of the inner layer.
According to the present invention, between the inner layer and the outer layer constituting the roller body, unlike the conventional coating material, it is non-porous and has a strong continuous film strength. Isolation can be ensured by an intermediate layer made of a plastic film that is unlikely to cause such a problem.

  Further, since the intermediate layer is formed by winding the plastic film around the outer peripheral surface of the inner layer in a cylindrical shape, the stress applied from the intermediate layer to the inner layer can be reduced to almost zero by adjusting the winding method. In addition, the stress can be adjusted to an arbitrary value. Therefore, unlike the conventional one having an intermediate layer made of a heat-shrinkable tube, the initial physical properties of the inner layer can be easily set to preset design values.

  Therefore, according to the present invention, the initial physical properties of the inner layer and the outer layer are set to preset design values, and the intermediate layer ensures that the component moves between the inner layer and the outer layer. As a result, the physical properties of the two layers largely fluctuate from the initial stage, and components that have moved from the inner layer to the outer layer do not bleed or bloom on the outer peripheral surface of the outer layer. It is possible to provide a paper feed roller that can be maintained.

It should be noted that both ends of the plastic film wound around the outer peripheral surface of the inner layer are completely separated from each other between the inner layer and the outer layer, so that the movement of the components described above is reliably prevented in the circumferential direction of the outer peripheral surface of the inner layer. It is in a state where they overlap each other.
The inner layer is formed of an elastomer, and the outer layer is formed of an elastomer that is harder than the inner layer. As a result, as described above, the contact area between the outer peripheral surface of the roller body and the paper can be secured, and the wear resistance of the roller body and the friction coefficient can be balanced while suppressing the decrease in the friction coefficient. It is possible to prevent the occurrence of paper conveyance failure and squealing for a longer period of time compared to the conventional single-layer structure.

The plastic film preferably has a thickness of 12 μm or more and 100 μm or less.
If thickness is less than the said range, there exists a possibility that the effect which prevents the movement of the component demonstrated previously by providing the intermediate | middle layer which consists of a plastic film may not fully be acquired. In particular, liquid components such as plasticizers and oils easily pass through the intermediate layer.

On the other hand, if the thickness exceeds the above range, a change in thickness at the overlap portion of the plastic film (a thickness that doubles here) causes a flare that occurs in the outer diameter of the outer layer, that is, the outer diameter of the roller body. There is a possibility that good paper feeding cannot be performed due to an increase in (outer diameter variation).
On the other hand, if the thickness of the plastic film is within the above range, the change in the thickness at the overlap portion is absorbed by the deformation of the inner layer and the outer layer, and the outer diameter is reduced as much as possible. It is possible to improve as much as possible the effect of preventing the movement of components by the intermediate layer made of a plastic film.

The plastic film is preferably a non-porous polyethylene terephthalate (PET) film.
The PET film is particularly excellent in the function of preventing permeation of liquid components and the like, and is more versatile than other plastic films having an equivalent function, and is advantageous in that it is easily available and inexpensive. is there.

The inner layer is preferably made of butyl rubber (IIR) or ethylene propylene rubber in a non-porous and cylindrical shape, and has a type A durometer hardness of 15 or less.
By forming the inner layer with such a soft elastomer, it is possible to secure a contact area between the outer peripheral surface of the roller body and the paper and to suppress a decrease in the friction coefficient. Further, by adopting a non-porous structure, the durability of the inner layer can be improved as compared with the case of a porous structure.

Further, when butyl rubber is used as the elastomer, since the butyl rubber is particularly excellent in vibration absorbing performance, it is possible to more reliably prevent the squeal described above.
On the other hand, when ethylene propylene rubber is used as the elastomer, the durability of the inner layer can be further improved because the ethylene propylene rubber is particularly excellent in resistance such as weather resistance and chemical resistance.

The outer layer is preferably made of ethylene propylene rubber or urethane rubber in a non-porous and cylindrical shape, and has a type A durometer hardness of 25 or more and 60 or less.
By forming the outer layer with an elastomer harder than the inner layer having the above-described hardness, it is possible to balance the wear resistance and the friction coefficient of the roller body. Further, by adopting a non-porous structure, the durability of the outer layer can be improved as compared with the case of a porous structure.

Further, when ethylene propylene rubber is used as the elastomer, the durability of the outer layer can be further improved because the ethylene propylene rubber is particularly excellent in resistance such as weather resistance and chemical resistance as described above.
On the other hand, when urethane rubber is used as the elastomer, since the urethane rubber is particularly excellent in weather resistance and wear resistance, the durability of the outer layer can be further improved.

  In the present invention, the type A durometer hardness of the inner layer and the outer layer is determined according to the Japanese Industrial Standard JIS K6253-3: 2006 “vulcanized rubber and thermoplastic rubber—determination of hardness—part 3: durometer hardness” In accordance with the measurement method listed, it is expressed as a value measured at 23 ° C.

  According to the present invention, the initial physical properties of the inner layer and the outer layer constituting the cylindrical roller body are set to preset design values, and the intermediate layer ensures that the components move between the two layers. As a result, the physical properties of the two layers largely fluctuate from the initial stage, and components that have moved from the inner layer to the outer layer do not bleed or bloom on the outer peripheral surface of the outer layer. A paper feed roller that can be maintained can be provided.

FIG. 4A is a perspective view showing an appearance of an example of the embodiment of the paper feed roller of the present invention, and FIG. 4B is a cross-sectional view of the roller body of the paper feed roller of the above example.

FIG. 1A is a perspective view showing the appearance of an example of an embodiment of a paper feed roller of the present invention, and FIG. 1B is a cross-sectional view of a roller body of the paper feed roller of the above example.
Referring to FIG. 1A, a paper feed roller 1 of this example includes a cylindrical roller body 3 having an outer peripheral surface 2 as a contact surface with paper, and a through hole 4 at the center of the roller body 3. And a shaft 5 inserted therethrough. The shaft 5 is made of, for example, metal, ceramic, hard resin, or the like.

Referring to FIGS. 1A and 1B, the roller body 3 includes a cylindrical inner layer 6, an intermediate layer 7, and an outer layer 8, respectively.
<Inner layer 6>
The inner layer 6 is formed in a cylindrical shape having the through holes 4 by an elastomer. The inner layer 6 is preferably non-porous and has a type A durometer hardness of 15 or less.

By forming the inner layer 6 with such a soft elastomer, it is possible to secure a contact area between the outer peripheral surface 2 of the roller body 3 and the paper and to suppress a decrease in the friction coefficient. Further, by adopting a non-porous structure, the durability of the inner layer can be improved as compared with the case of a porous structure.
In addition, the minimum of type A durometer hardness is not specifically limited, What is necessary is just one or more.
Further, the thickness of the inner layer 6 in the radial direction of the roller body 3 is preferably 2 mm or more, and preferably 10 mm or less.

If the thickness is less than the above range, the effect obtained by providing the inner layer 6 may not be sufficiently obtained. If the thickness exceeds the above range, the roller main body 3 may be unevenly worn and easily cause flare.
(Elastomer)
As the elastomer, IIR or ethylene propylene rubber is preferable.

Among these, as IIR, 1 type (s) or 2 or more types of various IIR which is a copolymer of isobutylene and isoprene can be used. As the IIR, for example, those having a proportion of isoprene units of about 1.5 mass% to 4.5 mass% are preferably used.
Specific examples of such IIR include, for example, JSR BUTYL268 manufactured by JSR Corporation (stabilizer: NS, unsaturation degree: 1.5 mol%, Mooney viscosity: 51 ML _{1 + 8} (125 ° C.), specific gravity: 0.92), JSR BUTYL 365 [Stabilizer: NS, Unsaturation degree: 2.0 mol%, Mooney viscosity: 33 ML _{1 + 8} (125 ° C.), Specific gravity: 0.92] and the like.

On the other hand, ethylene propylene rubber includes ethylene propylene rubber (EPM) in a narrow sense which is a copolymer of ethylene and propylene, and ethylene propylene diene rubber (EPDM) which is a copolymer of ethylene, propylene and diene. EPDM is preferred.
As EPDM, any of various copolymers obtained by copolymerizing ethylene, propylene, and diene can be used. 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.
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.
Examples of the ENB-based non-oil-extended EPDM in which the diene is ENB include at least one of Esprene 501A and 505A manufactured by Sumitomo Chemical Co., Ltd.

Further, examples of the DCDP-based non-oil-extended EPDM in which the diene is DCDP include one or more types such as esprene 301A, 301, and 305 manufactured by Sumitomo Chemical Co., Ltd.
As the EPDM, any one of the above examples may be used alone, or two or more kinds thereof may be used in combination.
A rubber composition containing the IIR or ethylene propylene rubber as a base polymer and blended with a crosslinking component such as a crosslinking agent and an accelerator, and an additive component such as a filler, a plasticizer, and an oil is formed into a cylindrical shape by, for example, press crosslinking. After being molded and crosslinked, the inner layer 6 is formed by cutting the length or polishing the outer peripheral surface as necessary.

<Middle layer 7>
The intermediate layer 7 is formed by winding a nonporous and continuous plastic film 9 in a cylindrical shape on the outer peripheral surface of the inner layer 6. Specifically, the plastic film 9 is fixed to the outer periphery along the outer peripheral surface while fixing the starting end (one end of winding) 9 a of the plastic film 9 to one place in the circumferential direction of the outer peripheral surface of the inner layer 6. The intermediate layer 7 is formed by winding in a cylindrical shape over the entire surface.

Unlike the conventional coating material as described above, the intermediate layer 7 is made of a non-porous plastic film 9 having a strong continuous film strength, and therefore is less likely to cause pinholes, scratches, peeling, and the like. Therefore, by providing the intermediate layer 7, the inner layer 6 and the outer layer 8 can be reliably separated from each other, and components can be prevented from moving between the two layers.
In addition, the intermediate layer 7 is formed by winding the plastic film 9 around the outer peripheral surface of the inner layer 6 in a cylindrical shape. Therefore, the intermediate layer 7 is added from the intermediate layer 7 to the inner layer 6 by adjusting the winding method. The stress can be made substantially zero, and the stress can be adjusted to an arbitrary value. Therefore, unlike the conventional one having an intermediate layer made of a heat-shrinkable tube, the initial physical properties of the inner layer 6 can be easily set to preset design values.

  Therefore, the initial physical properties of the inner layer 6 and the outer layer 8 are set to preset design values, and the intermediate layer 7 prevents components from moving between the inner layer 6 and the outer layer 8. In addition, since the physical properties of the two layers greatly fluctuate from the initial stage, and components that have moved from the inner layer 6 to the outer layer 8 do not bleed or bloom on the outer peripheral surface 2 of the outer layer 8, a good paper can be obtained over a long period of time. A paper feed roller 1 that can maintain the feed can be obtained.

The plastic film 9 may be bonded to the outer peripheral surface of the inner layer 6 with an adhesive, for example.
However, without using the adhesive, for example, while holding the plastic film 9 wrapped around the outer peripheral surface of the inner layer 6 in a cylindrical shape, the passage of the outer layer 8 whose inner diameter is slightly smaller than the outer diameter of the inner layer 6 is used. The press-fitting into the holes and integrating the layers without using any adhesive reduces the materials used and eliminates the step of applying the adhesive, thereby reducing the productivity of the paper feed roller 1. Can be improved.

The plastic film 9 has a starting end 9a and an end (one end of winding end) 9b that completely separates the inner layer 6 and the outer layer 8 from each other, and reliably prevents the movement of the components described above. b) As shown enlarged in the figure, the inner layer 6 is overlapped with each other in the circumferential direction of the outer peripheral surface.
The amount of overlap is not particularly limited, but is preferably 0.5 mm or more, and is preferably less than or equal to a half of the outer peripheral surface of the inner layer 6.

If the overlap amount is less than the above range, there is a possibility that the intermediate layer 7 cannot sufficiently separate the inner layer 6 and the outer layer 8, and if it exceeds the above range, the winding work time becomes longer, or the plastic film There is a risk that the consumption of 9 will increase.
The thickness of the plastic film 9 is preferably 12 μm or more and 100 μm or less.
If thickness is less than the said range, there exists a possibility that the effect which prevents the movement of the component demonstrated previously by providing the intermediate | middle layer 7 which consists of a plastic film 9 may not fully be acquired. In particular, liquid components such as plasticizers and oils easily pass through the intermediate layer 7.

On the other hand, when the thickness exceeds the above range, due to the change in the thickness of the overlap portion of the plastic film 9, the flare generated on the outer diameter of the outer layer 8, that is, the outer diameter of the roller main body 3, is increased. There is a risk that paper cannot be fed.
On the other hand, if the thickness of the plastic film 9 is within the above range, the thickness change at the overlap portion is absorbed by the deformation of the inner layer 6 and the outer layer 8, and the outer diameter flare is minimized. However, the effect of preventing the movement of components by the intermediate layer 7 made of the plastic film 9 can be improved as much as possible.

Examples of the plastic film 9 include, for example, a single layer or multiple layers of PET, polyamide, polyimide, polyethylene, carbide molecular weight polyethylene, polypropylene, polystyrene, polyphenylene sulfide, etc., and a non-porous film. Etc.
In particular, a non-porous PET film that is excellent in the function of preventing permeation of liquid components and the like, is more versatile than other plastic films having an equivalent function, and is easily available and inexpensive is preferable. .

<Outer layer 8>
The outer layer 8 is formed in a cylindrical shape provided with the outer peripheral surface 2 of the roller body 3 by an elastomer. The outer layer 8 is preferably non-porous and has a type A durometer hardness of 25 or more and 60 or less.
By forming the outer layer 8 with an elastomer harder than the inner layer 6, it is possible to balance the wear resistance and the friction coefficient of the roller body 3. Further, by adopting a non-porous structure, the durability of the outer layer can be improved as compared with the case of a porous structure.

The thickness of the outer layer 8 in the radial direction of the roller body 3 is preferably 1 mm or more, and preferably 3 mm or less.
If the thickness is less than the above range, the outer peripheral surface may be worn early, and the service life of the roller body 3 may be shortened. If the thickness exceeds the above range, the above-described effect by providing the inner layer 6 is sufficiently obtained. May not be obtained.

(Elastomer)
As the elastomer, ethylene propylene rubber or urethane rubber is preferable.
Of these, as the ethylene propylene rubber, one or more of the various ethylene propylene rubbers exemplified above for the inner layer 6 can be used.
As the urethane rubber, any of narrowly defined urethane rubber having thermosetting properties and thermoplastic urethane elastomer (TPU) can be used. In particular, TPU is preferable. As such TPU, for example, a hard segment having a polyurethane structure and a soft segment having a polyester or polyether structure are included in the molecule, and it has thermoplasticity capable of injection molding and the like, and a roller body. Any of various urethane-based thermoplastic elastomers having elasticity capable of functioning as the third outer layer 8 can be used.

  Specific examples of TPU include, for example, Elastollan (registered trademark) C60A10WN (JIS A hardness: 65 ± 4, with plasticizer), C70A10WN (JIS A hardness: 73 ± 4, plasticizer) manufactured by BASF Japan Ltd. 1 type or 2 types of TPU with relatively low hardness such as C70A11FG [JIS A hardness 75 ± 3, no plasticizer], ET870-11V [JIS A hardness: 71 ± 3, no plasticizer] The above is mentioned.

A rubber composition containing the ethylene-propylene rubber as a base polymer and blended with a crosslinking component such as a crosslinking agent and an accelerator, and an additive component such as a filler, a plasticizer, and an oil is formed into a cylindrical shape by, for example, press crosslinking. Then, after crosslinking, the outer layer 8 is formed by cutting the length or polishing the outer peripheral surface as necessary.
In addition, a thermoplastic elastomer composition containing the TPU as a base polymer and blended with additive components such as fillers, plasticizers, and oils is formed into a cylindrical shape by, for example, injection molding, and further lengthed as necessary. The outer layer 8 is formed by cutting or polishing the outer peripheral surface.

<Other components constituting the inner layer 6 and the outer layer 8>
(Crosslinking component)
Examples of the crosslinking component include a crosslinking agent, and one or more of accelerators, accelerators, and the like are used in combination with the crosslinking agent.
Among these, examples of the crosslinking agent include one or more of sulfur-based crosslinking agents, thiourea-based crosslinking agents, triazine derivative-based crosslinking agents, peroxide-based crosslinking agents, various monomers, and the like.

Examples of the sulfur-based crosslinking agent include powdered sulfur and organic sulfur-containing compounds. Examples of the organic sulfur-containing compound include tetramethylthiuram disulfide and N, N-dithiobismorpholine.
The thiourea-based cross-linking agent, such as tetramethyl thiourea, trimethyl thiourea, ethylene _thiourea, shows a _{(C n H 2n + 1 NH} ) 2 C = S wherein, n represents an integer from 1 to 10. And the like.

Examples of peroxide crosslinking agents include benzoyl peroxide.
Examples of the accelerator include inorganic accelerators such as slaked lime, magnesia (MgO), and resurge (PbO), and one or more of the following organic accelerators.
Examples of the organic accelerator include one or more of guanidine accelerator, thiazole accelerator, sulfenamide accelerator, thiuram accelerator, thiourea accelerator, dithiocarbamate accelerator, and the like. Can be mentioned. Since the function of the accelerator varies depending on the type, it is preferable to use two or more kinds of accelerators in combination.

Of the above, examples of the guanidine accelerator include 1,3-diphenylguanidine (D), 1,3-di-o-tolylguanidine (DT), 1-o-tolylbiguanide (BG), and dicatechol borate. 1 type, or 2 or more types, such as a di-o-tolyl guanidine salt, is mentioned.
Examples of thiazole accelerators include 2-mercaptobenzothiazole (M), di-2-benzothiazolyl disulfide (DM), zinc salt of 2-mercaptobenzothiazole (MZ), and cyclohexyl 2-mercaptobenzothiazole. One or two of amine salts (HM, M60-OT), 2- (N, N-diethylthiocarbamoylthio) benzothiazole (64), 2- (4′-morpholinodithio) benzothiazole (DS, MDB) and the like More than species.

Examples of the sulfenamide accelerator include N-cyclohexyl-2-benzothiazylsulfenamide.
Examples of the thiuram accelerator include tetramethylthiuram monosulfide (TS), tetramethylthiuram disulfide (TT, TMT), tetraethylthiuram disulfide (TET), tetrabutylthiuram disulfide (TBT-N), tetrakis (2-ethylhexyl) One type or two or more types such as thiuram disulfide (TOT-N) and dipentamethylene thiuram tetrasulfide (TRA) can be used.

  Examples of the dithiocarbamate accelerator include zinc dimethyldithiocarbamate (PZ), zinc diethyldithiocarbamate (EZ), zinc dibutyldithiocarbamate (BZ), zinc N-pentamethylenedithiocarbamate (ZP), and zinc dibenzyldithiocarbamate. (ZTC), sodium dibutyldithiocarbamate (TP), copper dimethyldithiocarbamate (TTCU), ferric dimethyldithiocarbamate (TTFE), and tellurium diethyldithiocarbamate (TTTE).

Examples of the acceleration aid include one or more of metal compounds such as zinc white; fatty acids such as stearic acid, oleic acid, and cottonseed fatty acid, and other conventionally known acceleration aids.
The blending ratio of the cross-linking agent, the accelerator, and the promoter aid is the same as the type, combination, and blend ratio of the base polymer, or the type and combination of the cross-linking agent, accelerator, and promoter, and the inner layer 6 and the outer layer 8. It can be set as appropriate according to the required type A durometer hardness.

(filler)
Examples of the filler include one or more of zinc oxide, silica, carbon, carbon black, clay, talc, calcium carbonate, magnesium carbonate, aluminum hydroxide, titanium oxide, and the like.
By blending the filler, the inner layer 6 and the outer layer 8 can be hardened, that is, the type A durometer hardness can be increased, and the mechanical strength and the like can be improved.

(Plasticizer, oil)
Examples of the plasticizer include Sanflex (registered trademark) EB-200, EB-300, and EB-400 (all of which are polyethylene glycol dibenzoates) manufactured by Sanyo Chemical Industries, Ltd., and Benzoflex manufactured by Eastman Chemical Co., Ltd. (Registered trademark) 9-88 [dipropylene glycol dibenzoate] and the like may be used.

Examples of the oil include paraffin oil [Diana (registered trademark) process oil PW-380 manufactured by Idemitsu Kosan Co., Ltd.].
Both the plasticizer and the oil may be used in combination, or only one of them may be used.
By blending a plasticizer and / or oil, the inner layer 6 and the outer layer 8 are soft, that is, the type A durometer hardness can be reduced.

(Mixing ratio of filler, plasticizer, oil)
As described above, the filler functions to harden the inner layer 6 and the outer layer 8, and conversely, the plasticizer and oil function to soften the two layers.
Therefore, the blending ratio of the filler, plasticizer, and oil depends on the characteristics required for the inner layer 6 and the outer layer 8, particularly the type A durometer hardness, and the type and hardness of the base polymer to be used together. Can be set as appropriate.

The configuration of the present invention is not limited to the example of the figure described above.
For example, the intermediate layer 7 may be formed of a plastic film having a laminated structure of two or more layers. Further, the inner layer 6 and the outer layer 8 may also be formed in a laminated structure of two or more layers.
Further, a concave portion such as a groove may be formed on the outer peripheral surface 2 of the outer layer 8. When the concave portion is provided, paper dust generated from the paper is taken into the concave portion, thereby suppressing a decrease in the coefficient of friction due to the adhesion of the paper dust to the outer peripheral surface 2, and good paper over a longer period. Feed can be maintained.

Further, the shaft 5 may be formed in a shape other than a cylindrical shape such as a prismatic shape for connection to a driving mechanism (not shown).
In addition, design changes can be made as appropriate without departing from the scope of the present invention.
The paper feed roller 1 according to the present invention includes, for example, an electrostatic copying machine, a laser printer, a plain paper facsimile machine, a complex machine thereof, an image forming apparatus such as an ink jet printer, an automatic cash dispenser (ATM), or the like. It can be used as various paper feed rollers such as a paper feed roller, a transport roller, a platen roller, and a paper discharge roller incorporated in a paper feed mechanism in the above-mentioned devices.

<Formation of outer layer A>
A rubber composition was prepared by blending the following components.

Each component in Table 1 is as follows.
(Base polymer)
Oil exhibition EPDM: Esprene (registered trademark) 670F manufactured by Sumitomo Chemical Co., Ltd., rubber content: extension oil = 100: 100 (mass ratio)
(filler)
Silica: Nipsil (registered trademark) VN3 manufactured by Tosoh Silica Corporation
Calcium carbonate: BF300 manufactured by Bihoku Powder Chemical Co., Ltd.
Titanium oxide: Trade name KRONOS titanium oxide KR-380 manufactured by Titanium Industry Co., Ltd.
Carbon black: Seast 3 made by Tokai Carbon Co., Ltd.
(oil)
Paraffin oil: Diana (registered trademark) process oil PW-380 manufactured by Idemitsu Kosan Co., Ltd.
(Crosslinking component)
Powdered sulfur: Cross-linking agent, manufactured by Tsurumi Chemical Co., Ltd. Accelerator TET: Tetraethylthiuram disulfide, Nouchira (registered trademark) TET manufactured by Ouchi Shinsei Chemical Co., Ltd.
Accelerator DM: Di-2-benzothiazolyl disulfide, Noxeller DM manufactured by Ouchi Shinsei Chemical Co., Ltd.
Zinc oxide: accelerating aid, two types of zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: accelerating aid, product name Tsubaki manufactured by NOF Co., Ltd. After press-crosslinking at 160 ° C. for 20 minutes, a cot having an inner diameter of 19 mm, an outer diameter of 23 mm, and a length of 60 mm was formed, and then the cot was cut into a length of 30 mm to form an outer layer A.

It was 25 when the type A durometer hardness at 23 ° C. of the outer layer A was measured by the measurement method described above.
<Formation of outer layer B>
As shown in Table 2 below, a rubber composition was formed in the same manner as the outer layer A except that no paraffin oil was blended, and after press-crosslinking, it was cut to form an outer layer B having the same shape and dimensions. .

Each component in Table 2 is the same as the outer layer A.
It was 30 when the type A durometer hardness at 23 ° C. of the outer layer B was measured by the measurement method described above.
<Formation of outer layer C>
As shown in Table 3 below, in addition to 200 parts by mass of oil-extended EPDM, 100 parts by mass of non-oil-extended EPDM [Esprene 505A manufactured by Sumitomo Chemical Co., Ltd.] was added, except that calcium carbonate was not added. A rubber composition was formed in the same manner as the outer layer A, press-crosslinked, and then cut to form an outer layer C having the same shape and size.

Each component in Table 3 is the same as the outer layer A except for non-oil-extended EPDM.
It was 60 when the type A durometer hardness at 23 ° C. of the outer layer C was measured by the measurement method described above.
<Formation of outer layer D>
TPU pellets of Elastollan (registered trademark) C70A11FG manufactured by BASF Japan, JIS A hardness 75 ± 3, no plasticizer, and plasticizer [polyethylene glycol dibenzoates, Sanyo Chemical Industries, Ltd. Flex (registered trademark) EB-300] was put in a pail can in the ratio shown in Table 4 below, and heated at 80 ° C. for 15 hours to impregnate the plasticizer in the pellets.

Next, the whole amount in the pail can, that is, the pellets impregnated with the plasticizer and the remaining plasticizer not impregnated with the pellets were twin-screw extruder [screw diameter 30 mm, L / D: 36D, rotation speed: 10 300 rpm] and continuously extruded while kneading, and then pelletized to prepare elastomer composition pellets.
Next, the pellets were supplied to a 50-ton injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd.) and injection-molded to form a cylinder with an inner diameter of φ19 mm, an outer diameter of φ23 mm, and a length of 40 mm. After time annealing, the outer layer D was formed by cutting to a length of 30 mm.

It was 50 when the type A durometer hardness at 23 ° C. of the outer layer D was measured by the measurement method described above.
<Formation of inner layer a>
A rubber composition was prepared by blending the following components.

Among each component in Table 5, IIR and accelerator TBT-N are as follows.
IIR: JSR BUTYL268 manufactured by JSR Corporation, stabilizer: NS, degree of unsaturation: 1.5 mol%, Mooney viscosity: 51 ML _{1 + 8} (125 ° C.), specific gravity: 0.92
Accelerator TBT-N: Tetrabutylthiuram disulfide, Noxeller TBT-N manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Other components are the same as those of the outer layer A.

Next, the rubber composition was filled into a mold, and press-crosslinked under pressure at 160 ° C. for 30 minutes to form a cotle having an inner diameter φ13.3 mm, an outer diameter φ20 mm, and a length of 60 mm. To form an inner layer a.
It was 10 when the type A durometer hardness at 23 ° C. of the inner layer a was measured by the measurement method described above.

<Formation of inner layer b>
As shown in Table 6 below, a rubber composition was prepared in the same manner as the inner layer a except that the amount of paraffin oil was 45 parts by mass, and after press-crosslinking, the inner layer b having the same shape and size was cut. Formed.

Each component in Table 6 is the same as the inner layer a.
It was 15 when the type A durometer hardness at 23 ° C. of the inner layer b was measured by the measurement method described above.
<Formation of inner layer c>
A rubber composition was prepared by blending the following components, and was subjected to press crosslinking in the same manner as the inner layer a except that the rubber composition was used, and then cut to form an inner layer c having the same shape and size.

Each component in Table 7 is the same as the outer layer A.
It was 15 when the type A durometer hardness at 23 ° C. of the inner layer c was measured by the measurement method described above.
<Example 1>
A shaft is press-fitted into the through hole of the inner layer a, and a non-porous PET film [Lumirror (registered trademark) manufactured by Toray Industries, Inc., thickness 25 μm] serving as an intermediate layer is formed on the outer peripheral surface thereof. A paper feed roller including a roller body having a three-layer structure of the inner layer a, the intermediate layer, and the outer layer A is manufactured by press-fitting into the through hole of the outer layer A in a state where both ends are overlapped in the circumferential direction. did.

In addition, the overlap amount of the circumferential direction of the said outer peripheral surface of the both ends of the said PET film was 1 mm.
<Example 2>
The inner layer a and the intermediate layer were the same as in Example 1 except that the non-porous PET film used as the intermediate layer was a Lumirror made by Toray Industries, Inc., having a thickness of 12 μm. , And a paper feed roller having a three-layer roller body of outer layer A was manufactured.

<Example 3>
The inner layer a and the intermediate layer were the same as in Example 1 except that the non-porous PET film used as the intermediate layer was a Lumirror made by Toray Industries, Inc., having a thickness of 100 μm. , And a paper feed roller having a three-layer roller body of outer layer A was manufactured.
<Example 4>
The inner layer a and the intermediate layer were the same as in Example 1 except that the non-porous PET film used as the intermediate layer was a Lumirror made by Toray Industries, Inc., having a thickness of 5 μm. , And a paper feed roller having a three-layer roller body of outer layer A was manufactured.

<Comparative example 1>
A paper feed roller including a roller body having a two-layer structure of the inner layer a and the outer layer A was manufactured by press-fitting into the through hole of the outer layer A without winding a PET film around the outer peripheral surface of the inner layer a.
<Comparative example 2>
In the same manner as in Example 1, except that a porous PET film (thickness 50 μm) manufactured by Toyobo Co., Ltd., which is porous, was used as the base PET film for the intermediate layer, the inner layer a, the intermediate layer, And the paper feed roller provided with the roller main body of the three-layer structure of the outer layer A was manufactured.

<Comparative Example 3>
A polyurethane-based coating material [Neo Rez R9330 manufactured by DSM Co., Ltd.] is applied to the outer peripheral surface of the inner layer a using a brush and dried at room temperature to form an intermediate layer having a thickness of 20 μm. A paper feed roller including a roller body having a three-layer structure of the inner layer a, the intermediate layer, and the outer layer A was manufactured by press-fitting inside.

The intermediate layer was previously provided with a region where the coating material was left uncoated by about 5 × 5 mm, thereby reproducing the defects of the intermediate layer.
<Example 5>
A paper feed roller including a roller body having a three-layer structure of the inner layer b, the intermediate layer, and the outer layer A was manufactured in the same manner as in Example 1 except that the inner layer b was used instead of the inner layer a.

<Example 6>
A paper feed roller including a roller body having a three-layer structure of the inner layer c, the intermediate layer, and the outer layer A was manufactured in the same manner as in Example 1 except that the inner layer c was used instead of the inner layer a.
<Example 7>
A paper feed roller including a roller body having a three-layer structure of an inner layer a, an intermediate layer, and the outer layer B was manufactured in the same manner as in Example 1 except that the outer layer B was used instead of the outer layer A.

<Example 8>
A roller body having a three-layer structure of the inner layer b, the intermediate layer, and the outer layer C in the same manner as in Example 1 except that the inner layer b is used instead of the inner layer a and the outer layer C is used instead of the outer layer A. A paper feed roller equipped with was manufactured.
<Example 9>
A roller body having a three-layer structure of the inner layer b, the intermediate layer, and the outer layer D in the same manner as in Example 1 except that the inner layer b is used instead of the inner layer a and the outer layer D is used instead of the outer layer A. A paper feed roller equipped with was manufactured.

<Moving component>
In accordance with the measuring method described in the Japanese Industrial Standard JIS K6257: 2010 “Vulcanized rubber and thermoplastic rubber—How to obtain heat aging characteristics”, the paper feeding roller produced in each of the above Examples and Comparative Examples was used at 70 ° C. After allowing to stand for 96 hours, the sulfur content in the central portion in the radial direction of the cross section obtained by cutting the outer layer with a razor was determined by the SEM / EDX method.

For the measurement, a scanning electron microscope S-3400N manufactured by Hitachi High-Technologies Corporation and an energy dispersive X-ray analyzer EMAX EVOLOTION EX270 manufactured by Horiba, Ltd. were used.
And about outer layer AC which itself contains sulfur, the measured sulfur amount is more than the said reference value by making into a reference value the sulfur amount measured by heat-processing similarly using the single-layered outer layer which is not made into the multilayer structure as a blank. Increase of 15% or more, increase of component is transferred (×), increase is 10% or more, less than 15% is transfer of component is very small, practical level (△), increase is 10% What was less than was evaluated as no component movement (O).

In addition, for the outer layer D that itself does not contain sulfur, the measured sulfur content exceeds 0.2% by mass with component movement (x), and the component with less than 0.2% by mass migration of component. Evaluated as none (O).
<Outer diameter flare>
The outer diameter of the central portion in the width direction of the paper feed roller manufactured in each of the above examples and comparative examples was measured using a laser outer diameter measuring machine manufactured by Keyence Corporation, and the flare was 0.3 or more. The outer diameter was evaluated as having an outer diameter flare (×), and the outer diameter being less than 0.3 (no).

  The above results are shown in Tables 8 to 10.

From the results of Comparative Example 1 in Table 8, it was found that when the intermediate layer was not provided between the inner layer and the outer layer, the component moved. Further, from the results of Comparative Examples 2 and 3 in Table 9, it was found that even if a porous plastic film or a film of a coating material having a defect was provided as the intermediate layer, the movement of components could not be prevented.
On the other hand, from the results of Examples 1 to 9 in Tables 8 to 10, it was found that the movement of components can be prevented by providing an intermediate layer made of a non-porous plastic film between the inner layer and the outer layer. . It has also been found that a PET film is preferable as the non-porous plastic film.

However, from the results of Examples 1 to 4, the plastic film has a thickness of 12 μm or more and 100 μm or less in order to prevent the movement of the component more reliably and prevent the occurrence of outer diameter flare. It turned out to be preferable.
Further, from the results of Examples 1 and 5 to 9, it is found that the outer layer is preferably non-porous and cylindrically formed by EPDM or TUP, and preferably has a type A durometer hardness of 25 or more and 60 or less. It was.

  From the results of Examples 1 and 5 to 9, it was found that the inner layer is preferably formed of a non-porous and cylindrical shape by IIR or EPDM and has a type A durometer hardness of 15 or less.

DESCRIPTION OF SYMBOLS 1 Paper feed roller 2 Outer peripheral surface 3 Roller main body 4 Through-hole 5 Shaft 6 Inner layer 7 Intermediate layer 8 Outer layer 9 Plastic film 9a Start end 9b End

Claims (5)

  A paper feed roller having a cylindrical roller body, the roller body having a three-layer structure including a cylindrical inner layer, an intermediate layer, and an outer layer, and the intermediate layer is an outer peripheral surface of the inner layer And a non-porous and continuous plastic film which is formed by winding it into a cylindrical shape.   The paper feed roller according to claim 1, wherein the plastic film has a thickness of 12 μm or more and 100 μm or less.   The paper feed roller according to claim 1, wherein the plastic film is a non-porous polyethylene terephthalate film.   4. The paper feed roller according to claim 1, wherein the inner layer is formed of a non-porous and cylindrical shape with butyl rubber or ethylene propylene rubber, and has a type A durometer hardness of 15 or less. 5.   The paper according to any one of claims 1 to 4, wherein the outer layer is formed of a non-porous and cylindrical shape with ethylene propylene rubber or urethane rubber, and has a type A durometer hardness of 25 or more and 60 or less. Feed roller.

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