JP2000006163A - Rubber roller and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber roller which enables a simple manufacturing process and a cost cut to be realized by preventing a coating film from being formed within the range of a face retained by a bearing, out of the outer peripheral face of the support shaft part of a conductive core and dispensing with an upstroking process for removing the coating film. SOLUTION: This rubber roller 1 has support shaft parts 4a, 4b formed on both ends of a core body part 3 with an elastic element layer 5 molded on the outer peripheral face and a single or plural reservoir grooves 7a, 7b formed on the outer peripheral face in a passage from the molding terminal positions 6a, 6b of the elastic element layer 5 in the core body part 3 upto a face area on which the support shaft parts 4a, 4b are retained by a bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copier, a laser printer or a facsimile receiving apparatus, and more particularly to a roller such as a developing roller, a charging roller and a transfer roller incorporated in an electrophotographic apparatus and a method of manufacturing the same. Things.

[0002]

2. Description of the Related Art Generally, an image forming process of an electrophotographic apparatus includes the following steps.
A charging step of uniformly charging the surface of the photoconductor having photoconductivity, an exposure step of exposing the surface of the photoconductor to image light to form an electrostatic latent image, and applying a colored resin powder (toner ) Is developed by electrostatically adsorbing and developing the toner image to make it visible as a toner image, a transfer step of transferring the toner image onto paper, and a fixing step of fixing the transferred image on paper by pressure or heat. ing. After the transfer step, the surface of the photoconductor is cleaned by scraping off the residual toner, and the steps such as charging, exposure, and development are repeated again. A charging roller is used in the charging step, a developing roller is used in the developing step, and a transfer roller is used in the transferring step. These various rollers are composed of a rubber roller having an elastic layer formed around a conductive core made of SUS, an aluminum alloy, a conductive resin, or the like,
Alternatively, if necessary, the outer periphery of the rubber roller may be covered with a resistance adjusting layer, a protective layer, or the like.

Referring to FIG. 8, a general method for manufacturing such a rubber roller will be described below. FIG. 8 is a schematic diagram showing a cross section of an injection mold having a cylindrical mold. The injection mold 70 has a cylindrical mold 71 and a core holding member 72 a which is fitted inside the upper and lower ends of the cylindrical mold 71 and holds the supporting shaft portions 92 a and 92 b of the conductive core 91. ,
72b, and cover members 73a and 73b screwed to the outer peripheral surface of the cylindrical mold 71 with the core body holding members 72a and 72b externally provided. Support shaft 92
When a and 92b are mounted on the electrophotographic apparatus, they are held by bearings provided on the electrophotographic apparatus. The production of the rubber roller by the injection mold 70 is performed as follows. First, the conductive core body 91 is disposed inside the cylindrical mold 71, and the upper and lower supporting shaft portions 92a and 92b are inserted and held in the shaft end holding holes 74a and 74b. Next, the cover members 73a and 73b are attached to the core holding members 72a and 72b.
In a state in which the lower core member b is externally mounted, the lower core member holding member 7 is screwed with the cylindrical mold 71, and then the material resin press-fitted from the injection nozzle mounting hole 75 formed in the lower cover member 73b is pressed.
The elastic layer forming space 77 is filled and molded through the resin injection hole 76 opened in 2b to form an elastic layer on the outer peripheral surface of the conductive core. Thereafter, the molded body is cooled together with the mold to a predetermined temperature, and is released from the cylindrical mold in the axial direction. Is produced. In FIG. 7, reference numeral 91 denotes a conductive core, 92a and 92b denote supporting shafts, 9
Reference numeral 3 denotes an elastic layer formed on the outer periphery of the conductive core.

[0004]

In the conventional molding method,
Shaft end holding hole 74a (or 74b) and supporting shaft portion 92a
(Or 92b) and the end surface 94a of the core body.
(Or 94b) and the core holding member 72a (or 72
It was necessary to provide a clearance of about 5 to 30 μm between b) and b).

The reason for providing such a clearance is as follows.
Mainly according to (1) and (2) below. (1) When a thermosetting resin is used as a material resin, the mold is filled with the thermosetting resin, and is heated and cured together with the mold at a high temperature. When the heating is performed in a state where there is almost no clearance, the supporting shaft portions 92a and 92b thermally expand in the radial direction and are firmly held in the shaft end holding holes 74a and 74b, and at the same time, the conductive core 91 also moves in the axial direction. Because of thermal expansion, a compressive stress is applied to the conductive core 91 in the axial direction, so that flexure deformation occurs. When an elastic layer is formed on the outer peripheral surface of the conductive core 91 in a state where this deformation occurs, an elastic layer that is significantly eccentric with respect to the axis of the conductive core is formed, and the rubber roller The dimensional accuracy is significantly reduced. (2) In a state where there is almost no clearance, the upper and lower supporting shaft portions 92a and 92b are connected to the shaft end holding holes 74 when the conductive core body is inserted and arranged in the mold or when the molded body is released.
a, 74b smoothly inserted into the shaft end holding hole 74.
a, 74b cannot be separated smoothly.

However, when the above-described clearance is provided, when the material resin is pressed into the mold, the material resin leaks to the supporting shaft through the clearance and hardens.
A thin film is formed. If this film is formed in the surface area held by the bearing of the supporting shaft, it becomes an obstacle when the rubber roller is mounted on the electrophotographic apparatus as a developing roller, a charging roller, or the like. Therefore, it is necessary to remove the film by a finishing process such as mechanical polishing, but this finishing process has contributed to an increase in manufacturing cost.

The present invention has been made in view of the above-mentioned circumstances, and a rubber roller capable of simplifying a manufacturing process and reducing costs by preventing the above-mentioned film formation and eliminating the need for finishing to remove the film. It is an object of the present invention to provide a manufacturing method thereof.

[0008]

In order to achieve the above object, a rubber roller according to the present invention comprises a core body having an elastic layer formed on an outer peripheral surface, and supporting shafts provided at both ends of the core body. One or more reservoir grooves are provided on an outer peripheral surface on a path extending from a molding end position of the elastic layer in the body main body portion to a range where the supporting shaft portion is held by the bearing.

Here, at least one step may be provided between the core body and the supporting shaft, and one or more storage grooves may be provided on the step surface.

The sectional shape of the reservoir groove may be V-shaped or rectangular.

As a method of manufacturing such a rubber roller, there is known a method of manufacturing a rubber core on a path extending from an end position of an intended area for forming an elastic layer of a core body to an area held by a bearing on an outer peripheral surface of a supporting shaft. One or more reservoir grooves are formed on the outer peripheral surface of the body, the support shaft is inserted and held in a shaft end holding hole provided in the mold, and the core is placed in a sealed mold, A material resin is press-fitted from an injection portion provided at one end of a mold, and an elastic layer is formed on the outer peripheral surface of the core body while the material resin leaking beyond the elastic layer forming range is stopped in the reservoir groove. Alternatively, a method can be used in which one or both ends of the mold are opened and the molded body is released from the open end side in the axial direction to obtain a final molded body. Thus, the reservoir groove provided on the outer peripheral surface of the core body functions as a resin reservoir.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, various exemplary embodiments according to the present invention will be described with reference to the drawings. The rubber roller according to the present invention includes a conductive core having a diameter of about 1 to 12 mm made of SUS, an aluminum alloy, a conductive resin, or the like, and an elastic layer formed on an outer peripheral surface of the conductive core. Be composed. When this rubber roller is mounted on an electrophotographic device as a developing roller, a charging roller, a transfer roller, etc., an elastic layer is further coated on the outer peripheral surface of the elastic layer according to the required characteristics of each roller. Or coating a resistance adjusting layer, a protective layer, or the like.

FIG. 1 is a schematic view showing a cross section of a first embodiment of a rubber roller according to the present invention. The rubber roller 1 according to the present embodiment includes a conductive core 2 composed of a core body 3 and support shafts 4 a and 4 b provided at both ends of the core body 3.
And an elastic layer 5 coated on the outer peripheral surface of the core body 3. When the supporting shafts 4a and 4b are mounted on the electrophotographic apparatus, they are held by bearings provided on the electrophotographic apparatus. Also, on the outer peripheral surface of the conductive core 2, the end position 6 a (or 6 b) of the elastic layer 5 is set.
The reservoir groove 7a (or 7b) is formed continuously along the entire circumference along the circumferential direction on the path extending from the support shaft portion 4a (or 4b). As will be described later, these reservoir grooves 7a and 7b prevent the resin film from being formed in the bearing holding range (the surface range held by the bearing) of the supporting shaft portions 4a and 4b in the rubber roller manufacturing process. .

As another embodiment according to the present invention, FIGS.
A rubber roller shown in FIG. The rubber roller 10 of the second embodiment shown in FIG. 2 has both ends reduced in diameter by steps.
A conductive core 11 having support shafts 12a and 12b and a core body 13 formed therein; reservoir grooves 14a and 14b formed on outer peripheral surfaces of the support shafts 12a and 12b; 13 on the outer peripheral surface. The storage grooves 14a and 14b have a V-shaped cross section and are formed continuously along the circumferential direction on the outer peripheral surfaces of the supporting shaft portions 12a and 12b.

The rubber roller 20 according to the third embodiment shown in FIG. 3 is different from the rubber roller 10 according to the second embodiment in the position where the reservoir groove is formed. In this embodiment, the storage grooves 21a and 21b having a V-shaped cross section are concentric with the axis at step surfaces 24a and 24b between the core body 22 and the supporting shafts 23a and 23b. Is formed.

In the rubber roller 30 of the fourth embodiment shown in FIG. 4, the reservoir grooves of the second and third embodiments are formed on the same conductive core. In this embodiment, compared to the above-described embodiment, a plurality of storage grooves 31a,
The formation of the resin film 32a (or 31b, 32b) in the bearing holding range of the supporting shafts 33a, 33b can be more reliably prevented.

The rubber roller 40 according to the fifth embodiment shown in FIG. 5 has a tapered outer peripheral surface at the ends 43a and 43b of the core body 42 connected to the supporting shafts 41a and 41b. The V-shaped reservoir grooves 44a and 44b are formed. These storage grooves 44a, 44b are formed continuously over the entire circumference along the circumferential direction on the outer peripheral surfaces of the tapered end portions 43a, 43b.

The various embodiments of the rubber roller according to the present invention have been described above. In any of the above embodiments, the reservoir groove is formed on the outer peripheral surface of the conductive core on the path from the elastic layer end position to the bearing holding range of the supporting shaft.

Further, in the above embodiment, the cross-sectional shapes of the reservoir grooves are all V-shaped, and the reservoir grooves are formed continuously along the circumferential direction on the outer peripheral surface of the conductive core. However, the present invention is not limited to these, and the cross-sectional shape of the storage groove may be, for example, a rectangular shape, and a plurality of the storage grooves may be formed intermittently on one circumference or a plurality of circumferences. Alternatively, it may be formed in a spiral shape. In addition, there is no particular limitation on the method of forming the reservoir groove, and a known cutting process or the like can be used.

A typical method for manufacturing such a rubber roller will be described below with reference to FIG. However, the injection mold used in the present invention is not limited to the injection mold described below. FIG. 6 shows a cylindrical mold 51.
FIG. 9 is a schematic cross-sectional view showing a state in which the conductive core 11 of the second embodiment is inserted into an injection molding die 50 provided with the above. The injection mold 50 includes a cylindrical mold 51 and this cylindrical mold 5.
1. Core holding members 52a, 52b which are internally fitted to the upper and lower ends of the support member 1 and hold the supporting shaft portions 12a, 12b of the conductive core 11.
And a cover member 53 that is screwed onto the outer peripheral surface of the cylindrical mold 51 with the core body holding members 52a and 52b being covered.
a, 53b.

First, before the conductive core body 11 is inserted into the injection mold 50, the above-described reservoir grooves 14a, 1
4b is formed. Next, the conductive core 11 is inserted and arranged inside the cylindrical mold 51, and the upper and lower supporting shafts 12 are disposed.
a and 12b are inserted and held in the shaft end holding holes 54a and 54b formed in the upper and lower core holding members. Next, the cover members 53a, 53b are connected to the core body holding members 52a, 52b.
Is screwed together with the cylindrical mold 51 in a state of being covered. Here, the shaft end holding hole 54a (or 54b) and the supporting shaft 1
2a (or 12b), and the core body main body end face 16
a (or 16b) and the core holding member 52a (or 52
A clearance of 5 to 30 μm is provided between b) in order to improve the dimensional accuracy of the molded body for the reasons described above.
The numerical range of the clearance is determined when designing both the conductive core and the mold in consideration of the dimensional accuracy.

Subsequently, the material resin press-fitted from the injection nozzle mounting hole 56 formed in the lower cover member 53b is filled into the elastic layer molding space 58 through the resin injection hole 57 formed in the lower core holding member 52b. Molded and core body 1
An elastic layer is formed around 3. At this time, a part of the filled resin material leaks from the elastic layer forming space 58 to the clearance, but before leaking to the bearing holding range of the supporting shaft portions 12a and 12b, the storage resin grooves 14a and 14b. Can be stopped. Thereafter, the molded body is cooled together with the mold to a predetermined temperature, and is released from the cylindrical mold 51 in the axial direction. Finally, the rubber roller 10 shown in FIG. 2 is manufactured.

As described above, the material resin leaked into the clearance is stopped by the reservoir groove which functions as a resin reservoir, so that the formation of the resin film in the bearing holding range of the supporting shaft portion of the rubber roller is prevented.

It is preferable that the cylindrical mold has a seamless pipe shape and the inner surface thereof is subjected to a fluorine resin coating or an electroless plating treatment from the viewpoint of improving the releasability of the molded body. It is also preferable to apply a primer to the outer peripheral surface of the conductive core before forming the elastic layer in order to increase the adhesive strength between the conductive core and the elastic layer. In addition, although the above-described injection molding die is of a vertical type, it may be of a horizontal type in the present invention.

Next, the resin composition constituting the elastic layer according to the present invention will be described below. Examples of the resin composition include those whose main components are oxyalkylene-based, saturated hydrocarbon-based, urethane-based, and siloxane-based resins, which contain a reactive organic material that solidifies from a liquid by a curing reaction. . Examples of the curing reaction include a reaction caused by an isocyanate group such as a urethanization reaction and a ureaization reaction, a hydrosilylation reaction, and a hydrolytic condensation reaction. As another resin composition, a thermoplastic resin, for example, ethylene-propylene rubber such as NBR (nitrile butadiene rubber), SBR (styrene butadiene rubber), CR (chloroprene rubber), EPDM, or a millable silicone rubber is used. It can also be used.

Among these resin compositions, the dimensional stability of the molded article is good due to relatively small curing shrinkage during molding of the elastic layer, and the productivity is good because the curing time is short. (A) a polymer containing at least one alkenyl group in the molecule, wherein the repeating unit constituting the main chain is mainly composed of an oxyalkylene unit or a saturated hydrocarbon-based unit; and (B) at least two polymers in the molecule. A curing agent containing a hydrosilyl group, (C) a hydrosilylation catalyst, and (D)
It is desirable to use a reaction product of a curable composition containing a conductivity-imparting agent and a main component.

The polymer of the component (A) in this curable composition is a component which is cured by a hydrosilylation reaction with the component (B), and has at least one alkenyl group in the molecule. Occurs to become a polymer and harden. The number of alkenyl groups contained in the component (A) must be at least one in view of hydrosilylation reaction with the component (B), but from the viewpoint of obtaining sufficient rubber elasticity, the number of In the case of a molecule having two alkenyl groups at both ends of the molecule and having a branch,
It is desirable that two or more alkenyl groups be present at the molecular terminals. The main repeating unit constituting the main chain of the component (A) is an oxyalkylene unit or a saturated hydrocarbon unit.

First, the case where the main repeating unit constituting the main chain of the component (A) is a polymer comprising an oxyalkylene unit will be described. At this time, an appropriate amount of a conductivity-imparting agent as the component (D) is added to the cured product, and the volume resistivity of the cured product is 10 ³ to 10 ¹⁰ Ωcm, particularly 10 ⁸ Ωcm to ^{10 9} Ω.
cm is preferable. From the viewpoint of lowering the hardness of the cured product, an oxyalkylene polymer in which the repeating unit is an oxyalkylene unit, and an oxypropylene polymer in which the repeating unit is an oxypropylene unit are preferable.

Here, the oxyalkylene polymer refers to a polymer in which 30% or more, preferably 50% or more of the units constituting the main chain are composed of oxyalkylene units. The unit contained other than the oxyalkylene unit contains 2 units of active hydrogen used as a starting material in the production of the polymer.
Compounds having at least one compound such as ethylene glycol, bisphenol compounds, glycerin, trimethylolpropane, and pentaerythritol. When the repeating unit is an oxypropylene-based unit, it may be a copolymer (including a graft copolymer) with a unit composed of ethylene oxide, butylene oxide, or the like.

The molecular weight of such an oxyalkylene polymer is from 500 to 50,000 in terms of number average molecular weight (Mn) from the viewpoint of improving the balance between reactivity and low hardness.
0, more preferably 1,000 to 40,000. In particular, those having a number average molecular weight of 5,000 or more,
Further, those having a molecular weight of 5,000 to 40,000 are preferable. When the number average molecular weight is less than 500, it becomes difficult to obtain sufficient mechanical properties (rubber hardness, elongation) and the like when the curable composition is cured. On the other hand, if the number average molecular weight is too large, the alkenyl group 1
Because the molecular weight per unit increases or the reactivity decreases due to steric hindrance, curing often becomes insufficient,
Further, the viscosity tends to be too high and the processability tends to be poor.

The alkenyl group contained in the oxyalkylene-based polymer is not particularly limited, but an alkenyl group represented by the following general formula (1) is particularly preferable because of its excellent curability.

H ₂ C ＝ C (R ¹ ) (1) (wherein R ¹ is a hydrogen atom or a methyl group)

One of the characteristics of the curable composition is that
It is easy to set the hardness to be low, and in order to exhibit this characteristic, it is preferable that the number of alkenyl groups is two or more at the molecular terminal. However, if the number of alkenyl groups is too large as compared with the molecular weight of the component (A), the composition becomes rigid and it is difficult to obtain good rubber elasticity.

Next, the case where the component (A) is a polymer in which the main repeating unit constituting the main chain is a saturated hydrocarbon unit will be described. This polymer is preferable in that it has a low water absorption and a cured product having small environmental fluctuation of electric resistance can be obtained. Further, similarly to the case of the oxyalkylene-based polymer, the component is a component which is cured by a hydrosilylation reaction with the component (B), and has at least one alkenyl group in the molecule. It becomes molecular and hardens. Further, the number of alkenyl groups contained in the component (A) is required to be at least one from the viewpoint of performing a hydrosilylation reaction with the component (B). In such a case, it is preferable that two are present at both ends of the molecule,
In the case of a molecule having a branch, it is preferable that two or more molecules exist at the molecular terminal.

Representative examples of the polymer in which the main repeating unit constituting the main chain is a saturated hydrocarbon unit include an isobutylene polymer, a hydrogenated isoprene polymer, and a hydrogenated butadiene polymer. These polymers may contain repeating units of other components such as copolymers, but contain at least 50% or more, preferably 70% or more, more preferably 90% or more of saturated hydrocarbon units. This is important so as not to impair the low water absorption characteristic of the saturated hydrocarbon system.

The molecular weight of the polymer of the component (A) in which the main repeating unit constituting the main chain is a saturated hydrocarbon unit is about 500 to 50,000 in terms of number average molecular weight (Mn), and more preferably about 1, About 000 to 15,000,
A liquid material having fluidity at room temperature is preferable in terms of ease of handling and workability.

The alkenyl group introduced into such a saturated hydrocarbon polymer is the same as the oxyalkylene polymer. Therefore, a preferred specific example of the polymer as the component (A), which contains at least one alkenyl group in the molecule and in which the main repeating unit constituting the main chain is a saturated hydrocarbon unit, is alkenyl at both terminals. Having two groups and a linear number average molecular weight (Mn) of 2,
000-15,000 and Mw / Mn is 1.1-1.2.
Polyisobutylene-based, hydrogenated polybutadiene-based, hydrogenated polyisoprene-based polymers, and the like. Where Mw
Is the weight average molecular weight.

The component (B) in the curable composition is not particularly limited as long as it is a compound having at least two hydrosilyl groups in the molecule, but the number of hydrosilyl groups contained in the molecule is too large. Then, even after curing, a large amount of hydrosilyl groups tends to remain in the cured product, causing voids and cracks. Therefore, the number of hydrosilyl groups contained in the molecule is preferably 50 or less. Further, this number is from 2 to 30 in view of control of rubber elasticity of the cured product and storage stability.
, More preferably 2 to 20,
Further, in order to easily prevent foaming at the time of curing, the number is preferably 20 or less, and 3 or more is preferable in that curing failure is unlikely to occur even when the hydrosilyl group is deactivated, and the most preferable range is 3 to 20. is there.

In the present invention, having one hydrosilyl group means having one H bonded to Si, and SiH ₂ means having two hydrosilyl groups. It is preferable that H bonded to Si is bonded to different Si from the viewpoint of curability and rubber elasticity.

The molecular weight of the component (B) is 30,000 or less in terms of number average molecular weight (Mn) from the viewpoint of dispersibility and roller workability when the conductivity imparting agent (D) is added. It is preferably 20,000 or less, more preferably 15,000 or less. In consideration of the reactivity and compatibility with the component (A), the number average molecular weight is 300 to 1
Preferably it is 000.

With respect to the component (B), since the cohesive force of the component (A) is greater than the cohesive force of the component (B), the phenyl group-containing modification is important in terms of compatibility. Styrene-modified products are preferred in terms of compatibility with the components and availability, and α-methylstyrene-modified products are preferred in terms of storage stability.

The hydrosilylation catalyst which is the component (C) is not particularly limited as long as it can be used as a hydrosilylation catalyst. Platinic acid (including complexes such as alcohols), various platinum complexes, rhodium,
Chloride of metals such as ruthenium, iron, aluminum, titanium and the like can be mentioned. Among these, chloroplatinic acid, a platinum-olefin complex, and a platinum-vinylsiloxane complex are preferable from the viewpoint of catalytic activity. These catalysts may be used alone or in combination of two or more.

The proportion of the component (B) to the component (A) in the curable composition as described above is such that the amount of the hydrosilyl group in the component (B) is 0.1 per mole of the alkenyl group in the component (A). When it is set to be 2 to 0.5 mol, more preferably 0.4 to 2.5 mol, it is preferable in that good rubber elasticity is obtained.

The amount of component (C) used is as follows:
(A) 10 ^-1 to 1 based on 1 mol of the alkenyl group in the component.
It is preferably used in the range of 0 ^-8 mol, particularly 10 ^-3 to 10 ^-6 mol. If the amount of the component (C) is less than 10 ^-8 mol, the reaction does not proceed. Use while the hydrosilylation catalysts are generally expensive and have a corrosive, and since the cured product hydrogen gas generate a large amount has a property that results in foaming exceeds 10 ^-1 mol It is preferable not to have them.

Further, by adding a conductivity-imparting agent as the component (D) to the curable composition to form a conductive composition,
It is suitable as a developing roller. Examples of the conductivity-imparting agent of the component (D) include carbon black, metal fine powder, and organic compounds having a quaternary ammonium base, a carboxylic acid group, a sulfonic acid group, a sulfate group, a phosphate group, and the like. Or a polymer, an ether ester amide, or an ether imide polymer, an ethylene oxide-epihalohydrin copolymer, a compound having a conductive unit represented by methoxypolyethylene glycol acrylate, or an antistatic agent such as a polymer compound, Examples thereof include compounds capable of imparting conductivity. These conductivity imparting agents may be used alone or in combination of two or more.

The amount of the conductivity-imparting agent as the component (D) should be not more than 30% by weight based on the total amount of the components (A) to (C). preferable. On the other hand, in order to obtain a uniform volume resistance, this addition amount is 1
The addition amount is preferably 0% by weight or more, and the addition amount is preferably determined so that the volume resistivity of the cured product is 10 ³ to 10 ¹⁰ Ωcm.

Further, in addition to the above-mentioned components (A) to (D), a storage stability improving agent such as a compound having an aliphatic unsaturated bond, an organic phosphorus compound, an organic sulfur compound, A nitrogen-containing compound, a tin-based compound, an organic peroxide, or the like may be added. Specific examples thereof include, for example, benzothiazole, thiazole, dimethylmalate, dimethylacetylenecarboxylate,
-Pentenenitrile, 2,3-dichloropropene, quinoline and the like, but is not limited thereto. Among these, thiazole and dimethyl malate are particularly preferred from the viewpoint of achieving both pot life and rapid curing properties. The storage stability improvers may be used alone or in combination of two or more.

Further, a filler, a storage stabilizer, a plasticizer, an ultraviolet absorber, a lubricant, a pigment, and the like may be added to the curable composition from the viewpoint of improving processability and cost.

[0049]

EXAMPLES Hereinafter, more specific examples and comparative examples of the rubber roller according to the present invention will be shown, and both will be compared.

(Elastic Layer) The elastic layer was formed by using the same kind of mold as the injection mold shown in FIG. 6 according to the following composition (A) to (D) and molding conditions. The conductive cores of Examples and Comparative Examples were formed on the outer peripheral surface. (A) 10 of allylated polyoxypropylene-based polymer (number average molecular weight (Mn) 8,000; molecular weight distribution 2)
(B) polysiloxane-based curing agent (1
6.6 parts by weight, (C) 10% isopropyl alcohol solution of chloroplatinic acid: 0.06 parts by weight, (D) carbon black (trade name of Mitsubishi Chemical Corporation) 3030B "): 6 parts by weight, and defoaming under reduced pressure at 10 mmHg or less for 120 minutes.
It was left standing for 30 minutes in an environment of 20 ° C. to be cured to form an elastic layer. The Japanese Industrial Standard (JIS) A hardness of this elastic layer was 15 °.

Example 1 A rubber roller having the cross-sectional shape shown in FIG. The SUS conductive core (diameter of supporting shaft 8 mm; diameter of central part 8 m)
In the supporting shafts 4a and 4b of m), V-shaped grooves 7a and 7b having a depth of 0.6 mm and a width (W ₁ ) of 1.0 mm were formed along the circumferential direction. An elastic layer 5 having a thickness of 3 mm and a total length (L ₁ ) of 230 mm is formed on the outer peripheral surface of the core body 3.

Example 2 A rubber roller having the cross-sectional shape shown in FIG. The conductive core made of SUS (diameter of supporting shaft portion: 5 mm; diameter of central portion of main body: 8 m)
m), the supporting shaft portions 12a and 12b have a V of 0.6 mm in depth and 1.0 mm in width (W ₂ ) along the circumferential direction.
The U-shaped grooves 14a and 14b were formed. On the outer peripheral surface of the core body 13, a thickness of 3 mm and a total length (L ₂ ) 23
The elastic layer 15 of 0 mm is formed.

Example 3 A rubber roller having the cross-sectional shape of FIG. The conductive core made of SUS (diameter of supporting shaft portion: 5 mm; diameter of central portion of main body: 8 m)
m), the step surfaces 24a and 24b between the supporting shaft portions 23a and 23b and the core body main body 22 have a radius (R) from the shaft center.
The position of 3.25 mm, depth 0.5 mm, a width (W ₃₎
1.0 mm concentric storage grooves 21a and 21b were formed. On the outer peripheral surface of the core body 22, a thickness of 3 mm,
The elastic layer 25 having a total length (T ₃ ) of 230 mm is formed.

Embodiment 4 Embodiment 2 as shown in FIG.
A rubber roller was produced by combining Example 3 and Example 3 to obtain Example 4.

(Comparative Example 1) A rubber roller having the same configuration as that of the above-mentioned Example 1 was produced, except that a conductive core body having no reservoir groove was used.

100 rubber rollers of each of Examples 1 to 4 and Comparative Example 1 were produced, and the formation state of the resin film on the supporting shaft of each rubber roller was visually observed. As a result, five resin films were found to need to be removed in Example 1, four in Example 2, three in Example 3, and two in Example 4. A book,
In the case of Comparative Example 1, there were 100 pieces.

[0057]

As described above, the rubber roller according to the present invention has one or a plurality of rubber rollers on the outer peripheral surface of the core on the path from the molding end position of the elastic layer in the core body to the bearing holding range of the supporting shaft. Since the storage groove is provided, in the process of manufacturing the rubber roller of the present invention, the material resin leaked from the elastic layer forming space can be stopped in the storage groove, so that the storage groove functions as a resin storage. Further, it is possible to prevent the resin film from being formed in the bearing holding range of the supporting shaft. Therefore, a finishing process for removing the resin film is not required, so that a low-cost rubber roller can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first embodiment of a rubber roller according to the present invention.

FIG. 2 is a schematic diagram showing a second embodiment of the rubber roller according to the present invention.

FIG. 3 is a schematic view showing a third embodiment of the rubber roller according to the present invention.

FIG. 4 is a schematic diagram showing a fourth embodiment of the rubber roller according to the present invention.

FIG. 5 is a schematic view showing a fifth embodiment of the rubber roller according to the present invention.

FIG. 6 is a schematic diagram showing a state in which the conductive core according to the present invention is inserted into a mold for injection molding.

FIG. 7 is a schematic view showing a cross section of a conventional rubber roller.

FIG. 8 is a schematic diagram showing a conventional injection molding die.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Rubber roller 2 Conductive core 3 Core body 4a, 4b Supporting shaft 5 Elastic layer 6a, 6b Elastic layer end position 7a, 7b Reservoir groove 10 Rubber roller 11 Conductive core 12a, 12b Supporting shaft 13 Core body 14a, 14b Reservoir groove 15 Elastic layer 16a, 16b Core body end face 20 Rubber roller 21a, 21b Reservoir 22 Core body 23a, 23b Supporting shaft 24a, 24b Step surface 25 Elastic layer Reference Signs List 30 Rubber rollers 31a, 31b, 32a, 32b Reservoir groove 40 Rubber rollers 41a, 41b Supporting shaft part 42 Core body main bodies 43a, 43b Core body main body end 44a, 44b Reservoir groove 50 Injection molding die 51 Cylindrical mold 52a, 52b Core holding member 53a, 53b Cover member 54a, 54b Shaft end holding hole 56 Injection nozzle mounting hole 57 Resin injection Entry hole 58 Elastic layer forming space 59 Gas vent hole 60 Hole 61 Pin closing the hole 70 Injection mold 71 Cylindrical mold 72a, 72b Core holding member 73a, 73b Cover member 74a, 74b Shaft end holding Hole 75 Injection nozzle mounting hole 76 Resin injection hole 77 Elastic layer forming space 78 Gas vent hole 79 Hole 80 Pin closing the hole 90 Rubber roller 91 Conductive core 92a, 92b Supporting shaft 93 Elastic layer 94a, 94b Core body end face

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H003 BB11 BB13 BB16 CC05 2H032 AA05 2H077 AD06 FA13 FA16 FA22 4F204 AA45L AH04 AH33 AJ02 AJ03 AM33 EA03 EB01 EB12 EF05 EF23 EK07

Claims (4)

[Claims] 1. A supporting shaft portion is provided at both ends of a core body having an elastic layer formed on an outer peripheral surface, and the supporting shaft is provided from a molding end position of the elastic layer in the core body. A rubber roller, wherein one or a plurality of storage grooves are provided on an outer peripheral surface on a path reaching a range where a portion is held by a bearing. 2. The rubber roller according to claim 1, wherein at least one step is provided between the core body and the supporting shaft, and one or more storage grooves are provided on the step surface. 3. The rubber roller according to claim 1, wherein a cross-sectional shape of the storage groove is V-shaped or rectangular. 4. A method of manufacturing a rubber roller in which a supporting shaft is provided at both ends of a core body having an elastic layer formed on an outer peripheral surface thereof, wherein the elastic body layer is to be formed at an end of the core layer main body. From the position, one or more reservoir grooves were formed on the outer peripheral surface of the core body on a path extending to a range held by the bearing on the outer peripheral surface of the supporting shaft portion, and the supporting shaft portion was provided in a mold. Inserting and holding in the shaft end holding hole, placing the core in a sealed mold, press-fitting material resin from an injection part provided at one end of the mold,
An elastic layer is formed on the outer peripheral surface of the core body while the material resin leaking beyond the elastic layer forming range is stopped in the reservoir groove, and one end or both ends of the mold are opened to open the formed body. A method for producing a rubber roller, comprising releasing a mold from the side in the axial direction to obtain a final molded product.