JP2000343622A - Manufacture of rubber roller having coating layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a rubber roller to provide a stable image by forming a coating film uniform in its thickness by a vertically dipping method, suppressing an outer diameter variation of a coating layer formed on an outer periphery of an elastic material layer, and upgrading a dimensional accuracy. SOLUTION: The method for manufacturing a rubber roller comprises the steps of preparing a roller-like elastic material formed with an elastic material layer 3 on an outer periphery of a conductive core 2 and a cylindrical member 10 having an end face peripheral edge 10a substantially the same shape as that of an end face peripheral edge 3a of the layer 3, dipping a roller-like elastic material in a state perpendicular to a coating liquid, lifting the material, then bringing the edge 3a of the layer 3 into contact with the edge 10a of the member 10, releasing both, and then drying the film to form a coating layer.

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 copying machine, a laser printer or a facsimile receiving apparatus, and more particularly to a developing roller, a charging roller and a transfer roller which are incorporated in an electrophotographic apparatus employing an electrophotographic process. The present invention relates to a method for manufacturing a rubber roller.

[0002]

2. Description of the Related Art Generally, an image forming process of an electrophotographic apparatus includes the following steps.
A charging step of charging the photoconductive photoconductor surface, an exposure step of exposing the surface of the photoconductor to image light to form an electrostatic latent image on the surface, and applying a colored resin powder to the electrostatic latent image The method includes a developing process in which the toner image is visualized by being attracted, a transfer process in which the toner image is transferred to a sheet, and a fixing process in which the transferred image is fixed to the sheet by applying pressure or heat. After the transfer step, the surface of the photoreceptor is cleaned by removing the residual toner, and the steps such as charging, exposure, and development are repeated again. Various rollers are used in each of these steps. 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 transfer step.

[0003] In recent years, the need for higher image quality of electrophotography has increased, and there has been a strict demand for higher accuracy of the outer diameter of the roller as described above. For example, in the case of a contact type developing roller that supplies toner by contacting the photoreceptor surface, or a charging roller that contacts the photoreceptor surface and charges the surface, if the outer diameter is not accurate, the distance between the photoreceptor and the roller is reduced. Fluctuates in the nip width and contact pressure of the image, and image quality defects such as image unevenness easily occur.
Further, in the case of a non-contact type developing roller that supplies toner in a non-contact state with the photoconductor, the gap width between the both fluctuates, and image quality defects are likely to occur.

On the outer peripheral surface of this type of roller, several μm to several tens μm are applied by dip coating or spray coating.
In many cases, a resin coating layer is formed. Due to this coating layer, toner filming in the developing roller (a phenomenon in which toner adheres to the roller surface due to long-term use)
, The chargeability of the toner can be improved, the charging roller can be prevented from being unevenly charged, and the transfer roller can have improved toner releasability.

[0005]

Among the above-mentioned methods for forming a coating layer, the dipping method includes the following steps:
A “vertical dipping method” in which the roller-like elastic body 21 is dipped and applied with the long axis direction of the roller perpendicular to the surface of the coating liquid 20, as shown in FIG. There is a "horizontal dip method" in which the long axis direction of the elastic body 21 is horizontal, and the outer surface of the roller-like elastic body 21 is dipped and applied while rotating the elastic body.
When the roller-shaped elastic body is separated from the coating liquid surface, a phenomenon called liquid drainage due to surface tension occurs, and the thickness of the liquid-covered coating layer becomes larger than other layer thicknesses, and the outer diameter tends to vary. Therefore, there is a tendency that the vertical dipping method, which has a relatively small variation in the thickness of the coating layer and is simple, is adopted. However, even in the vertical dipping method, when the roller-like elastic body is separated from the coating liquid surface, liquid is drawn by the action of the surface tension of the coating liquid and the gravity, and in particular, approximately from the lower end of the roller which is lower at the time of dipping. The thickness of the coating layer within 20 mm becomes larger than the other layer thickness, and the outer diameter of the roller may vary.

[0006] The present invention is intended to solve the problem in view of such a situation, by making the thickness of the coating film by the vertical dip method uniform, suppressing the outer diameter variation of the coating layer formed on the outer peripheral surface of the elastic layer, It is an object of the present invention to provide a method of manufacturing a rubber roller that improves dimensional accuracy and provides stable image quality.

[0007]

In order to solve the above-mentioned problems,
As a result of studying and studying a coating method for removing the excess coating liquid remaining at the lower end of the roller at the time of vertical dipping, the method of manufacturing a rubber roller of the present invention has a single layer or a single layer on the outer peripheral surface of the conductive core. A roller-shaped elastic body formed by forming an elastic body layer composed of a plurality of layers, and a cylindrical member having an end surface periphery having substantially the same shape as an end surface periphery of the elastic body layer,
After the roller-like elastic body is immersed in a vertical state with respect to the coating liquid and dipped up, the lower edge peripheral edge of the elastic layer is brought into contact with the upper edge peripheral edge of the cylindrical member, and after separating them, And drying the coating film on the outer peripheral surface of the elastic layer to form a coating layer on the outer peripheral surface of the elastic layer. That is, when the roller-like elastic body is pulled up from the coating liquid, extra coating liquid adheres to the lower end of the roller due to the surface tension of the coating liquid, but the peripheral edge of the lower end face of the elastic body layer and the upper end face of the cylindrical member. By contacting the peripheral portion, the excess coating liquid can flow down to the outer peripheral surface of the cylindrical member, so that the thickness of the coating film becomes uniform.

Further, in order to improve the drainage of the roller-like elastic body after the roller-like elastic body is pulled up from the coating liquid and to make it easy for excess coating liquid to flow down to the cylindrical member, the outer peripheral end of the roller-like elastic body is gradually formed. It is preferable to form the tapered shape or the rounded shape to reduce the diameter.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing one embodiment of a rubber roller according to the present invention, and FIG. 2 is a schematic sectional view of the rubber roller. The rubber roller 1 of this embodiment has an elastic layer 3 formed on the outer peripheral surface of a conductive core 2 having an outer diameter of about 1 mm to 12 mm made of SUS, an aluminum alloy, a conductive resin, or the like. Is formed by forming a coating layer 4 having a thickness of about 10 μm to 50 μm on the outer peripheral surface of the substrate. The elastic layer 3 has a single layer or a plurality of layers such as a resistance adjusting layer for adjusting the electrical resistance of the rubber roller, a primer layer for improving the adhesiveness with the coating layer 4, and the like, as layers in contact with the coating layer 4. You may.

The elastic layer 3 is formed by curing a resin at a predetermined temperature for a predetermined time by extrusion molding or injection molding using a resin material described later. Further, after the elastic layer 3 is formed by the extrusion molding method, the conductive core 2 may be penetrated through the axis of the elastic layer 3 and fixed using an adhesive or the like, or may be injected. The elastic layer 3 may be injection-molded around the conductive core 2 disposed in the molding space in the molding die.

A method of forming the coating layer 4 on the outer peripheral surface of the roller-shaped elastic body having the elastic body layer 3 provided around the conductive core body 2 will be described in detail below. First, the roller-like elastic body is immersed in a coating liquid for a predetermined time by a vertical dipping method. As the coating liquid, an organic solvent such as N, N-dimethylformamide (DMF), methyl ethyl ketone (MEK), isopropyl alcohol (IPA), toluene, methanol, or a solution obtained by dissolving a resin material in an aqueous system can be used. Among the resin materials, when a developing roller is manufactured, from the viewpoint of preventing toner filming and toner charging properties, a polyurethane-based resin or a polyamide-based resin containing a -NHCO- bond in a molecule, or a nylon or fluorine-based resin is used. Resins are preferable, and when a charging roller or a transfer roller is manufactured, a fluororesin is preferable. Further, in order to control the surface roughness and the roller resistance of the rubber roller, resin-based fine particles, conductive metal oxide, carbon black, and the like may be mixed and dispersed in the coating liquid.

The viscosity of the coating solution is 5 to 200 cP.
(Centipoise) is preferably adjusted, but since the layer thickness changes depending on the viscosity, 10 to 100 cP is suitable for obtaining a typical coating layer thickness of 10 to 50 μm.

Next, after the roller-shaped elastic body is pulled up from the coating liquid, the liquid is drained by reciprocating up and down. Here, in order to reduce the consumption of the coating liquid, it is desirable to perform liquid drainage on the coating liquid. Next, as shown in FIG. 3A, a cylindrical member 10 having an end face peripheral edge 10a having substantially the same shape as the end face peripheral edge 3a of the elastic body layer 3 is prepared, and the roller-like elastic body is brought into a vertical state. While being maintained, it is transferred onto the cylindrical member 10, and then, as shown in FIG. 3B, one end 2 a of the conductive core is placed in the hollow portion 10 b of the cylindrical member 10, and The peripheral edge 3a of the end face is brought into contact with the peripheral edge 10a of the upper end face of the cylindrical member 10, and the excess coating liquid accumulated at the lower end of the elastic layer 3 is allowed to flow down to the outer peripheral face of the cylindrical member 10 so as to form a coating film. The thickness is made uniform. The roller-like elastic body pulled up from the coating liquid may be quickly brought into contact with the cylindrical member without draining the liquid, but the amount of the coating liquid adhering to the cylindrical member is reduced to maintain the cylindrical member. In order to extend the period, it is better to drain the liquid.

Further, in the illustrated example, the outer diameter of the lower end surface of the elastic layer 3 and the outer diameter of the upper end surface of the cylindrical member 10 are made substantially equal to each other so that the lower end surface peripheral portion 3a of the elastic layer 3 Member 1
0 and the upper end surface peripheral portion 10a substantially coincide with each other. In this case, the difference between the outer diameter of the lower end surface of the elastic body layer 3 and the outer diameter of the upper end surface of the cylindrical member 10 is adjusted within 1 mm in order to transmit the excess coating liquid well. Is preferred.

Further, in order to make it easier for the coating liquid to flow down, it is desirable to provide a cutout at a part of the peripheral edge of the end surface of the cylindrical member. Specifically, as shown in FIG.
A notch 10c extending in the axial direction from a part of the peripheral edge portion 10a of the cylindrical member 10 is provided. Thereby, when the lower end surface of the elastic layer 3 pulled up from the coating liquid comes into contact with the upper end surface of the cylindrical member 10 having the notch 10c formed thereon, excess coating liquid easily flows down through the notch 10c.
It is possible to realize a uniform coating film.

Further, as shown in FIG. 5 (a), in order to improve the drainage of the roller-like elastic body pulled up from the coating liquid and to improve the transmission of the excess coating liquid to the outer peripheral surface of the cylindrical member. In addition, the outer peripheral end 3b of the elastic layer 3 may be tapered so that the diameter gradually decreases toward the end, or the outer peripheral end 3b of the roller may be formed in a round shape as shown in FIG. preferable. In addition, corresponding to these end shapes, the peripheral surface of the end surface of the cylindrical member 10 has a shape substantially coinciding with the tapered end portion in the case of FIG. 4A, and has a round shape in the case of FIG. The shape is substantially the same as the end of the shape.
In order to obtain such a tapered shape or a rounded shape, a molding space in a mold may be provided with a wall surface corresponding to the tapered shape or the rounded shape, and may be formed at the same time as the elastic layer forming, Alternatively, it may be formed by shaving off a corner after forming the elastic layer.

Next, the roller-shaped elastic body is transferred to a drying oven, dried at a predetermined temperature for a predetermined time, and a solvent component is evaporated to form a coating layer 4 according to the present invention. In the vertical dipping method, since the thickness of the coating layer is likely to be different between the upper and lower portions of the outer peripheral surface of the roller, in order to reliably prevent this, the roller is turned upside down after a series of dipping steps is completed. It is preferable to perform the above-mentioned dipping step again.

It goes without saying that the above-described method of forming the coating layer is also applied to the formation of the resistance adjusting layer, the primer layer and the like constituting the above-mentioned elastic layer.

When a polyurethane resin is used as a main component of the resin material constituting the coating layer, particularly, from the viewpoint of availability and toner filming, polycarbonate urethane, ether urethane, and volume resistivity can be easily adjusted, which is preferable. Particularly, polycarbonate urethane and acryl-modified urethane are preferable from the viewpoint of easily obtaining a suitable roller resistance.

The above-mentioned polycarbonate urethane is obtained by adding a polycarbonate polyol and a polyisocyanate, and if necessary, a chain extender such as a glycol or an amine.
It is a compound obtained by reacting in the presence or absence of a solvent. The polycarbonate polyol preferably has a number-average molecular weight (Mn) in the range of about 300 to 15,000. Specifically, a polyhydric alcohol and phosgene, chloroformate, dialkyl carbonate, diallyl carbonate, and the like are preferably used. Examples of the polyhydric alcohol include a condensation polymer. In particular, 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, and 1,5-pentanediol are preferable. The polycarbonate polyol is preferably used alone, but may be used in combination with a polyester polyol, a polyether polyol, or a polyester-polyether polyol. Examples of the polyisocyanate that reacts with the polycarbonate polyol include tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), xylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), hydrogenated MDI, Examples include hydrogenated TDI and isophorone diisocyanate (IPDI). Of these, hydrogenated MDI and IPDI are preferred from the viewpoint of obtaining a good balance of the availability, production cost, and characteristics required for a rubber roller. is there.

Further, as the acrylic-modified urethane, it is desirable that the hydroxyl groups contained in both the acrylic resin and the urethane resin are urethanized with diisocyanate and bonded, in view of the fact that the reaction easily proceeds.

From the viewpoint of preventing toner filming, it is particularly preferable that the polyurethane resin contains a polysiloxane skeleton. As a result, the cohesive energy of the coating layer is reduced, so that the coating layer has good toner releasability, and further has the characteristics of a polyurethane resin that negatively charges the toner well and increases abrasion resistance. It becomes possible. In order to sufficiently exhibit such effects, the content of the polysiloxane skeleton in the polyurethane resin should be 5% by weight to 70% by weight, particularly 5% by weight to 4% by weight.
It is preferably 5% by weight, more preferably 20% to 40% by weight. It should be noted that such a polyurethane-based resin has a property such as silicone-modified polycarbonate polyol.
The molecule may include a polysiloxane skeleton and another skeleton at the same time.

The polyurethane resin containing such a polysiloxane skeleton comprises a reactant obtained by adding a polyol, an isocyanate and, if necessary, a chain extender, and at least one of the polyol and the chain extender has a polysiloxane skeleton. Is used. As the polyol, one or two or more of polysiloxane polyols such as polydimethylsiloxane polyol, polyethylene diadipate, polyethylene butylene adipate, polytetramethylene ether glycol, poly-ε-caprolactone diol, polycarbonate polyol, and polypropylene glycol are used. No. Among them, the use of polycarbonate polyol is particularly preferred from the viewpoint of preventing a decrease in toner charge amount under a high temperature and high humidity environment. As the polycarbonate polyol, for example, an aliphatic or alicyclic polycarbonate polyol such as polyhexamethylene carbonate diol is more preferable.

Further, as the isocyanate, known 4,4′-diphenylmethane diisocyanate (MD
I), cyclohexane diisocyanate, hydrogenated MDI,
Isophorone diisocyanate, 1,3-xylylene diisocyanate, 2,4-tolylene diisocyanate,
One or more kinds such as 2,6-tolylene diisocyanate are exemplified. Furthermore, urethane prepolymers obtained by reacting these isocyanates with polyols and polyamines so as to have an isocyanate group at the molecular terminal can also be used.

Further, as the chain extender, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, ethylenediamine,
Trimethylenediamine, tetramethylenediamine, hexamethylenediamine, isophoronediamine (IPD
A) and one or more of hydrazine and the like.

Next, the resin composition used in the elastic layer will be described in detail below. As the resin composition constituting the elastic layer, oxyalkylene-based, saturated hydrocarbon-based,
It is desirable to use a resin containing a urethane-based or siloxane-based component as a main component and containing a reactive organic material that solidifies from a liquid by a curing reaction. As this curing reaction,
Examples of the reaction include a reaction caused by an isocyanate group such as a urethanization reaction and a urea reaction, a hydrosilylation reaction, and a hydrolytic condensation reaction. Further, instead of such a resin composition, NBR (nitrile butadiene rubber),
It is also possible to use ethylene-propylene rubber such as SBR (styrene butadiene rubber), CR (chloroprene rubber), EPDM, and a millable silicone rubber.

Among the above-mentioned resin compositions, the curing shrinkage during the formation of the elastic layer is relatively small, so that the variation in the shape and dimensions of the molded product is small, and the curing time is short, so that the productivity is good. It is particularly desirable to use the following curable resin composition.

That is, (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; (C) a hydrosilylation catalyst, and (D) a conductivity-imparting agent.

The polymer of the component (A) is a component which is cured by a hydrosilylation reaction with the component (B), and has at least one alkenyl group in the molecule. And hardens. (A)
The number of alkenyl groups contained in the component is required to be at least one from the viewpoint of hydrosilylation reaction with the component (B). However, from the viewpoint of obtaining sufficient rubber elasticity, in the case of a linear molecule, In the case of a molecule having two alkenyl groups at both ends of the molecule and a branched molecule, it is preferable that two or more alkenyl groups are present at the molecular end.

The polymer in which the main repeating unit constituting the main chain of the component (A) is an oxyalkylene unit will be described below. Such a polymer is prepared by adding an appropriate amount of a conductivity-imparting agent, which is the component (D), to the cured product to increase the volume resistivity of the cured product to 10 ³ to 10 ¹⁰ Ωcm, particularly 10 ⁸ to ¹⁰ Ωcm.
^This is preferable because it can be easily adjusted within the range of ⁹ Ωcm. Further, such a polymer, from the viewpoint of lowering the hardness of the cured product, an oxyalkylene-based polymer containing the oxyalkylene unit as a repeating unit, and further, an oxypropylene-based polymer containing an oxypropylene unit as a repeating unit. Polymers are preferred.

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 (Mn) of 5,000 or more, more preferably 5,000 to 40,000 are preferred. When the number average molecular weight is less than 500, sufficient mechanical properties (rubber hardness,
On the other hand, if the number average molecular weight is too large, the molecular weight per alkenyl group contained in the molecule will increase, and the reactivity will decrease due to steric hindrance. In many cases, the viscosity tends to be too high, and the workability tends to deteriorate due to too high a viscosity.

The alkenyl group contained in the oxyalkylene polymer is not particularly limited, but an alkenyl group represented by the following general formula (1) is preferred 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, a polymer in which the main repeating unit constituting the main chain of the component (A) is a saturated hydrocarbon-based unit will be described. This polymer is preferable in that a cured product having a low water absorption rate and a small environmental change in electric resistance can be obtained, and, like the oxyalkylene-based polymer, the component (B) It is a component that is cured by a hydrosilylation reaction and has at least one alkenyl group in the molecule, so that the hydrosilylation reaction takes place to form a polymer and cure. 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 number average molecular weight (Mn), and more preferably 1, A liquid material having a fluidity at room temperature, which is about 000 to 15,000, 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. Accordingly, in the component (A), preferred specific examples of the polymer containing at least one alkenyl group in the molecule and the main repeating unit constituting the main chain being a saturated hydrocarbon unit include alkenyl groups at both terminals. Having two linear average number molecular weights (Mn)
Is 2,000 to 15,000, and Mw / Mn is 1.1 to
1.2 polyisobutylene-based, hydrogenated polybutadiene-based,
A hydrogenated polyisoprene-based polymer and the like can be mentioned.

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. In addition, this number is from 2 to 30, from the viewpoint of control of rubber elasticity of the cured product and storage stability.
More preferably, the number is 2 to 20, more preferably 20 or less in terms of easily preventing foaming at the time of curing, and 3 in order that hard curing failure hardly occurs even if the hydrosilyl group is deactivated. The above is preferable, and the most preferable range is 3 to
There are 20.

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 in terms of number average molecular weight (Mn) from the viewpoint of dispersibility and roller workability when the conductivity-imparting agent (D) is added.
Or less, more preferably 20,000 or less,
In particular, 15,000 or less is preferable. Considering the reactivity and compatibility with the component (A), the number average molecular weight is 300 to
It is preferably 10,000.

Regarding 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 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 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 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 hardly proceeds. 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 a 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 an organic compound 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, ether ester amide,
Or ether imide polymer, ethylene oxide
Examples of the compound include a compound having a conductive unit represented by an epihalohydrin copolymer, methoxypolyethylene glycol acrylate, or a compound capable of imparting conductivity, such as an antistatic agent such as a polymer compound. These conductivity imparting agents may be used alone or in combination of two or more.

The added amount of the conductivity-imparting agent as the component (D) is 30% by weight based on the total amount of the components (A) to (C).
The following is preferable from the viewpoint of not increasing the rubber hardness. On the other hand, in order to obtain a uniform volume resistivity, the addition amount is preferably 10% by weight or more, and the addition amount is adjusted so that the volume resistivity of the cured product is 10 ³ to 10 ¹⁰ Ωcm. Is preferred.

Further, the above curable composition contains the above (A)
In addition to the components (D) to (D), a storage stability improver, for example, a compound having an aliphatic unsaturated bond, an organic phosphorus compound, an organic sulfur compound, a nitrogen-containing compound, a tin compound, an organic peroxide, or the like is added. May be. Specific examples thereof include benzothiazole, thiazole, dimethylmalate, dimethylacetylenecarboxylate, 2-pentenenitrile,
Examples include, but are not limited to, 2,3-dichloropropene, quinoline, and the like. Of these, thiazole and dimethyl malate are particularly preferred from the viewpoint of achieving both pot life and rapid curing properties.
The storage stability improver may be used alone,
More than one species may be used in combination.

From the viewpoint of improving processability and cost, the curable composition contains a filler, a storage stabilizer,
Plasticizers, ultraviolet absorbers, lubricants, pigments and the like may be added.

[0051]

EXAMPLES Hereinafter, more specific examples and comparative examples according to the present invention will be described, but the following examples do not limit the present invention at all.

Example 1 A conductive elastic layer having a thickness of 4.0 mm was formed around a SUS shaft having a diameter of 12 mm by the following procedure. That is, (A) the number average molecular weight (M
n) Allyl-terminated polyoxypropylene-based polymer having a molecular weight distribution (Mw / Mn) of 8,000: 100 parts by weight, and (B) a polysiloxane-based curing agent (SiH value: 0.
36 mol / 100 g): 6.6 parts by weight, (C) 10% isopropyl alcohol solution of chloroplatinic acid: 0.06 parts by weight, and (D) carbon black 3030B (manufactured by Mitsubishi Chemical Corporation): 7 parts by weight. And reduced pressure (10 mmHg or less,
The resin material obtained by defoaming is poured around a SUS shaft previously placed in a molding space in a mold, and left to stand for 30 minutes in an environment of 120 ° C. to be cured. A roller-shaped elastic body having an elastic layer of 4 mm was produced.

On the other hand, a coating solution was prepared in the following procedure. That is, 150 g of polyhexamethylene carbonate diol (number average molecular weight 2,000) and 50 g of polydimethylsiloxane polyol (number average molecular weight 2,000) were used.
g, and 32 g of cyclohexane diisocyanate, charged in a 2,000 ml three-necked flask, reacted with stirring (100 ° C., 4 hours),
A prepolymer having a CO group was prepared. Next, after cooling this prepolymer to 50 ° C., 580 g of DMF (dimethylformamide) was charged, and 9.6 g of 1,6-hexanediol was added dropwise little by little, and a chain extension reaction (100 ° C.,
3 hours), the DMF: MEK =
A solution was prepared by diluting to about 6% with a 1: 1 solvent. Further, Seika Seven U having an average particle size of 6 μm was added to this solution.
P-0908 (manufactured by Dainichi Seika Co., Ltd.) was mixed at a ratio of 40 parts by weight to 100 parts by weight of the solid content to prepare a coating liquid. The viscosity of this coating solution was 15 cP (centipoise).

Next, while supporting the roller-shaped elastic body in a vertical state with respect to the surface of the coating liquid, the roller-shaped elastic body was immersed in the coating liquid for about 5 seconds so that the upper end of the roller-shaped elastic body was immersed. The roller-like elastic body is quickly pulled up and reciprocated up and down for 5 seconds in a state of being separated from the liquid surface to drain the liquid.
As shown in, the outer diameter is 16.0 mm and the inner diameter is 12.1 mm
After pressing the lower end surface of the elastic layer 3 against the upper end surface of the cylindrical member 10 for 1 minute and separating them, the roller-shaped elastic body is transferred to a drying furnace and dried at 140 ° C. for 1 hour. A coating layer was formed around the layer to produce a rubber roller of this example.

(Example 2) The rubber roller of the present example was manufactured by performing the same vertical dipping process as that of the above-mentioned Example 1 by turning the rubber roller of the above-mentioned Example 1 upside down.

(Embodiment 3) In each of the first and second vertical dipping steps of the embodiment 2, when the lower end surface of the elastic layer 3 is pressed against the upper end surface of the cylindrical member 10, the contact state and the non-contact state are obtained. A rubber roller of this example was manufactured in the same procedure as in Example 2 except that the pressing was performed while repeating the state.

Comparative Example A rubber roller of this comparative example was manufactured in the same procedure as in Example 1 except that the step of pressing the lower end surface of the roller-like elastic body against the cylindrical member was omitted.

(Measurement Environment) The outer diameters of the rubber rollers of the above Examples 1 to 3 and Comparative Example were measured using a laser measuring instrument, and variations in the outer diameters were obtained. The measurement points are two points 2 mm inward from both ends of the elastic layer (points A1 and A2), the center of the roller (point B), and two points in the middle between points A1 and A2 and point B ( C1 point, C2 point) for a total of 5 points,
The difference between the minimum value and the maximum value of these measured values was defined as “outside diameter variation”. Table 1 below shows these measured values and the value of “outer diameter variation”.

[0059]

[Table 1]

As is evident from Table 1, the rubber rollers of the examples have extremely small variations in the outer diameter as compared with the comparative examples, and the dimensional accuracy of the outer diameter is remarkably improved.

[0061]

As described above, according to the method for manufacturing a rubber roller of the present invention, a roller-shaped elastic body having an elastic layer formed on the outer peripheral surface of a conductive core, and a peripheral edge of the elastic layer are provided. Part, and a cylindrical member having an end surface peripheral edge having substantially the same shape, and immersing the roller-like elastic body in a vertical state with respect to the coating liquid, and after pulling up, the lower end surface peripheral edge of the elastic body layer Is brought into contact with the peripheral edge of the upper end surface of the cylindrical member, and after separating them, the coating film is dried on the outer peripheral surface of the elastic layer to form a coating layer. Excess coating liquid attached to the lower end portion when pulled up is transmitted to the outer peripheral surface of the cylindrical member and flows down, so that the thickness of the coating film is uniform, and the thickness of the coating layer is not varied,
It is possible to reduce the variation in the outer diameter of the rubber roller.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing one embodiment of a rubber roller according to the present invention.

FIG. 2 is a schematic sectional view showing one embodiment of a rubber roller according to the present invention.

FIG. 3 is a schematic view showing one embodiment of a coating step according to the present invention.

FIG. 4 is a schematic perspective view showing one embodiment of a cylindrical member according to the present invention.

FIG. 5 is a schematic side view showing a relationship between a lower end portion of the roller-shaped elastic body according to the present invention and a cylindrical member.

6A is a schematic diagram for explaining a vertical dip method, and FIG. 6B is a schematic diagram for explaining a horizontal dip method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rubber roller 2 Conductive core 2a One end of conductive core 3 Elastic layer 3a Peripheral edge of elastic layer 4 Coating layer 10 Cylindrical member 10a Peripheral edge of cylindrical member 10b Hollow portion of cylindrical member 10c Notch 20 coating Working fluid 21 Roller-like elastic body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/08 501 G03G 15/08 501D 4F213 15/16 103 15/16 103 // B29K 21:00 F term (Ref.) WA87 WB01 WB11 WB18 WW02 WW06 WW17 WW33

Claims (2)

[Claims] 1. A roller-shaped elastic body having a single layer or a plurality of elastic layers formed on an outer peripheral surface of a conductive core, and an edge peripheral edge having substantially the same shape as an edge peripheral edge of the elastic layer. A cylindrical member having a portion is prepared, and the roller-shaped elastic body is immersed in a vertical state with respect to the coating liquid, and after being pulled up, the lower edge peripheral edge of the elastic layer is moved to the upper edge peripheral edge of the cylindrical member. A method of manufacturing a rubber roller, comprising: contacting an outer peripheral portion of an elastic body layer; separating the two; and drying the coating film on the outer peripheral surface of the elastic body layer to form a coating layer on the outer peripheral surface of the elastic body layer. 2. The method of manufacturing a rubber roller according to claim 1, wherein a roller-shaped elastic body formed in a tapered shape or a rounded shape in which an outer peripheral end portion is gradually reduced in diameter is prepared.