JPH11348056A - Manufacture of elastic roller and molding device using therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacturing method of an elastic roller, which can manufacture the elastic roller having a surface layer without increasing the number of processes such as the formation of the surface layer on the surface of a molded body by taking the molded body out of a mold after the formation of an elastic layer and can form the the uniform surface layer without developing a mottled coating and the deviation of a core, and a molding device used for the method. SOLUTION: In order to manufacture an elastic roller consisting of a cylindrical elastic layer 10, on the outer periphery of which a surface layer 12 is provided, and a core body 4, the core body 4 is coaxially fixed into a tubular mold 1. Next, an elastic layer material is filled in the tubular mold 1. After the cure shrinkage of the elastic layer material, a surface layer material is filled in a gap 11 developed due to the curing of the elastic layer material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an elastic roller having a core and a molding apparatus used for the same.
In particular, the present invention relates to a technique suitable for manufacturing an elastic developing roller to be mounted on a developing device used in an electrophotographic copying machine or a printer.

[0002]

2. Description of the Related Art Various types of developing devices have been proposed for use in the above-described electrophotographic copying machines and printers. For example, a magnetic developer adsorbed by a magnetic roller is transferred to a photosensitive member. I have.

[0003] However, in the method of supplying the magnetic developer using such a magnetic roller, not only is the magnetic roller expensive, but also the adjustment of the gap between the magnetic roller and the photosensitive member is delicate. In addition, there is also a disadvantage that a precision of .1 mm is required, and a mechanism for satisfying the precision becomes complicated. In particular, when a magnetic two-component developer is used, the carrier itself has a limited life and needs to be replaced periodically, for example, every 10,000 to 20,000 copies, and the replacement operation is troublesome and troublesome. Further, since a magnetic material having a different color is internally added to the magnetic developer itself, it has been technically difficult to convert the magnetic developer into a color toner.

[0004] In order to solve such inconveniences, several developing methods using a non-magnetic developer have been proposed.
For example, a developing method has been proposed in which a non-magnetic developer (hereinafter, simply referred to as “developer”) is conveyed using an electric attraction force. In this developing method, the developer is frictionally charged between a regulating blade that regulates the accumulation thickness of the developer on the surface of the developing roller and the surface of the developing roller, so that the developer is prevented from cracking due to the pressure of the regulating blade. The use of a developing roller having a shaft covered with a flexible elastic layer (hereinafter referred to as an “elastic developing roller”) has been studied. The elastic layer is formed by using a resin composition as a main component, such as ethylene-propylene rubber such as NBR (nitrile butadiene rubber) and EPDM, silicone, urethane, etc., and may be exposed directly to the surface of the elastic developing roller. In addition, a thin surface layer is often provided on the surface for the purpose of controlling the charging characteristics and transportability of the developer. The resin composition which is the main component of the surface layer includes silicone, hydrocarbon, fluorine-based rubber, polycarbonate urethane, acryl-vinyl acetate copolymer, acryl-modified urethane, and the like, and further controls the surface roughness. Spherical fine particles, fibrous whiskers, or the like may be added for the purpose of improving the transportability and charging characteristics of the developer.

In order to control the density of an image by applying a direct current or an alternating current or both superimposed currents to an elastic developing roller as an electrophotographic developing system, the elastic layer and the surface layer appropriately control the resistance. If necessary, a conductivity-imparting agent such as carbon, metal powder, or a conductive polymer is added, and the roller resistance value of the elastic developing roller is 10 ⁴ to 1
It is adjusted within the range of 0 ¹⁰ Ω.

[0006]

On the other hand, a method of manufacturing the elastic developing roller provided with these surface layers is, for example, as shown in FIG. 7, a cylindrical mold 51 and a core body at both ends of the cylindrical mold. 54
Forming device 5 having core holding members 52 and 53 for supporting both ends of the upper and lower core holding members 52, and a vent hole 55 in the upper core holding member 52 and an injection hole 56 in the lower core holding member 53.
0, the elastic layer material is injected from the injection hole 56 while evacuating the gas from the gas vent hole 55, and the elastic layer material is cured by heating or cooling to form an elastic layer around the core 54. After removing the molded product from the molding device 50, the outer periphery of the elastic layer is further coated with a surface layer material by a roll coater method or a spray coating method to form a surface layer.

In such a conventional manufacturing method, a forming step of forming an elastic layer by a forming apparatus 50 and a coating step of coating a surface layer on the elastic layer after removing a molded product from the forming apparatus 50 are performed. This requires two steps, which increase the manufacturing cost due to the increase in the number of steps. In addition, when coating the surface layer, coating spots and blurring tend to occur, which causes image defects. There was such a problem.

The present invention has been made in view of such a situation, and involves an increase in the number of steps, such as forming a surface layer on the surface of the molded body after removing the molded body from the mold after forming the elastic layer. An object of the present invention is to provide a method of manufacturing an elastic roller capable of manufacturing an elastic roller having a surface layer without forming the surface layer, and forming a uniform surface layer without causing unevenness of coating or center blur, and a molding apparatus used for the same. It is.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, when the elastic layer material hardens and contracts, the space between the elastic layer surface and the inner surface of the cylindrical mold is reduced. Paying attention to the formation of a gap, the inventor has found that a uniform surface layer can be formed in the same mold by injecting a surface layer material into the gap and curing the same, thereby completing the present invention.

That is, according to the present invention, in manufacturing an elastic roller comprising a cylindrical elastic layer having a surface layer on the outer periphery and a core, the core is fixed coaxially in a cylindrical mold, and It is an object of the present invention to provide a manufacturing method characterized by filling an elastic layer material in a cylindrical mold, curing and contracting the elastic layer material, and then filling a surface layer material into a gap generated by the contraction. . In such a manufacturing method, it is possible to continuously form the elastic layer and the surface layer in the same mold without taking out a molded product. No uniform surface layer is formed. Further, the outer diameter of the roller after the formation of the surface layer is determined by the inner surface dimension of the molding space, and an elastic roller free of center blur and capable of maintaining good image quality can be obtained.

As the elastic layer material, (A) a polymer containing at least one alkenyl group in a molecule, and a repeating unit constituting a main chain mainly comprising an oxyalkylene unit or a saturated hydrocarbon unit; It is preferable to use a curable composition mainly composed of (B) a curing agent containing at least two hydrosilyl groups in a molecule, (C) a hydrosilylation catalyst, and (D) a conductivity-imparting agent.

As the core, a metal shaft, a conductive resin shaft or a shaft obtained by inserting a metal shaft into a conductive resin layer can be used.

[0013] The molding device used for manufacturing the elastic roller includes a core holding member for supporting both ends of the core and a cylindrical mold, and the core holding member includes an elastic layer. It is proposed to provide a first injection hole for injecting a material and a second injection hole for injecting a surface layer material.
In such a molding apparatus, even if each material adheres and remains in each injection hole, the injection hole of the surface layer material is provided independently of the injection hole of the elastic layer material, so that the elastic layer is formed on the surface layer. The inconvenience of mixing the layer material is avoided, the physical properties of the surface layer are stabilized, and the charging characteristics and transportability of the developer are accurately controlled.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, referring to the attached drawings,
The manufacturing method and the manufacturing apparatus of the elastic roller of the present invention will be described in detail based on an example showing the manufacturing of the elastic developing roller.
FIG. 1 shows a molding apparatus according to the present invention, in which A indicates a molding apparatus, 1 indicates a cylindrical mold, and 2 and 3 indicate core holding members, respectively.

As shown in FIG. 1, a molding apparatus A of this embodiment is of a vertical type, and has a cylindrical mold 1 and an upper part supporting both ends of a core 4 at both ends of the cylindrical mold 1. Core body holding member 2
And a lower core holding member 3, and the upper core holding member 2
The lower core body holding member 3 is provided with a first injection hole 6 for injecting the elastic layer material and a second injection hole 7 for injecting the surface layer material.

Since the cylindrical mold 1 has a seamless pipe shape, burrs are not generated on the side surface of the roll portion which greatly affects the development quality, and a uniform surface state is maintained in the circumferential direction of the roll portion. An elastic developing roller can be formed. The inner surface of the cylindrical mold 1 is preferably subjected to a fluororesin coating or an electroless plating treatment in order to improve the releasability of the molded product.

Although a straight metal shaft is used as the core 4 in this embodiment, the core of the elastic developing roller manufactured by the manufacturing method or the molding apparatus of the present invention is as follows.
It is not particularly limited to the metal shaft as long as it has conductivity for applying a voltage to the elastic layer and sufficient bending rigidity for supporting the elastic developing roller without bending, for example, as shown in FIG. The shaft 4a and the roll 4 are made of conductive resin.
a shaft 14 formed by inserting a metal shaft as the shaft portion 4a into the conductive resin layer 13 formed as the roll portion 4b as shown in FIG.
Are also preferred embodiments. As described above, if the core body 4 in which the large-diameter roll portion 4b is formed using a conductive resin capable of forming a layer having a smaller linear expansion coefficient and a smaller water absorption than the elastic layer is used, the metal shaft becomes thicker. It is possible to manufacture an elastic developing roller that can reduce the thickness of the elastic layer to the required minimum without increasing the diameter, suppress the change in the outer diameter due to environmental changes such as temperature and humidity during use, and maintain good image quality.
Such a conductive resin is made of a conductive material and a synthetic resin, and as the conductive material, metal powder, conductive carbon, a conductive polymer, or the like can be used. As the synthetic resin, polyester, polyamide, polyethylene, polycarbonate, or the like can be used. A thermosetting resin or a thermoplastic resin having little dimensional change due to the environment can be used.

In the molding apparatus of this embodiment, the gas vent hole 5 is formed separately from the injection holes 6 and 7, but as shown in FIG. A first mounting through-hole 6 'for both injecting material and venting, and a second mounting through-hole 7' for injecting surface layer material and venting.
It is also preferable to form a hole. As shown in FIG. 5, such a mounting through hole is a hole that is expanded upward or a cylindrical hole, and the diameter of the hole is determined by the injection nozzles 6a and 7a.
a is formed to be larger than the outer diameter of a to form a gap k for degassing, or the hole diameter is set to a size that can fit an injection nozzle, and a gas vent groove is provided on the side surface along the hole. Is done.

Although the above-described molding apparatus A is of a vertical type, the molding apparatus of the present invention may be of a horizontal type.

As the material for the elastic layer, NBR (nitrile butadiene rubber), EPDM, silicon, urethane, etc., and their foaming materials are used. There is no particular limitation, but a curable composition described below is preferable. It is an example. Since the elastic layer made of the reaction-cured product of the curable composition has a particularly flexible structure, the elastic layer can sufficiently exhibit its elasticity effect even when the thickness is reduced. In addition, when containing an oxyalkylene unit, it is easy to handle because it has a low viscosity before curing, and when it contains a saturated hydrocarbon unit, it has a low water absorption and little change in volume and roller resistance even in a high humidity environment. It is preferred in that respect.

That is, as the elastic layer material, (A) a polymer having at least one alkenyl group in a molecule and a repeating unit constituting a main chain mainly comprising an oxyalkylene unit or a saturated hydrocarbon unit; (B) a curing agent having at least two hydrosilyl groups in the molecule;
(C) a hydrosilylation catalyst, (D) a conductivity-imparting agent,
It is preferable to use a curable composition containing as a main component.

The polymer of the component (A) in the 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. It occurs and becomes polymer and hardens. The number of alkenyl groups contained in the component (A) is required to be at least one from the viewpoint of hydrosilylation reaction with the component (B), but from the viewpoint of rubber elasticity,
In the case of a linear molecule, two alkenyl groups are present at both ends of the molecule. In the case of a branched molecule, two alkenyl groups are present at the molecular terminal.
Preferably, there are at least two alkenyl groups.
The main repeating unit constituting the main chain of the component (A) is an oxyalkylene unit or a saturated hydrocarbon unit.

In the case of a polymer in which the main repeating unit constituting the main chain is an oxyalkylene unit, the volume resistance is 10 ⁸ Ωcm to 10 ⁹ by adding only a small amount of a conductivity-imparting agent.
Ωcm is preferable. Further, from the viewpoint of lowering the hardness of the cured product, an oxyalkylene-based polymer in which the repeating unit is an oxyalkylene unit, and more preferably an oxypropylene-based polymer in which the repeating unit is an oxypropylene unit.

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. Examples of the unit include compounds derived from compounds having two or more active hydrogens, such as ethylene glycol, bisphenol compounds, glycerin, trimethylolpropane, and pentaerythritol, which are used as starting materials in the production of polymers. . In the case of an oxypropylene-based polymer, a copolymer (including a graft copolymer) with a unit composed of ethylene oxide, butylene oxide, or the like may be used.

The alkenyl group contained in the oxyalkylene polymer is not particularly limited, but may be represented by the following general formula (1):

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

The alkenyl group represented by the following formula (1) is particularly preferred in terms of excellent curability.

One of the characteristics of the curable composition is that
In order to exhibit this characteristic, the number of alkenyl groups is preferably 2 or more at the molecular terminal, and the number of alkenyl groups becomes too large compared to the molecular weight of component (A). And it becomes difficult to obtain good rubber elasticity.

In the case where the component (A) is a polymer in which the main repeating unit constituting the main chain is a saturated hydrocarbon unit, it has a low water absorption, and is preferably small in environmental fluctuation of electric resistance. This polymer is also a component which is cured by a hydrosilylation reaction with the component (B), as in the case of the oxyalkylene polymer, and has at least one alkenyl group in the molecule. The component (A) is required to have at least one alkenyl group from the viewpoint of a hydrosilylation reaction with the component (B).
From the viewpoint of rubber elasticity, in the case of a linear molecule, two molecules are preferably present at both ends of the molecule, and in the case of a molecule having a branch, two or more molecules are preferably present at the molecular terminal.

Representative examples of the polymer in which the main repeating unit constituting the main chain is a saturated hydrocarbon-based unit include:
Examples include an isobutylene-based polymer, a hydrogenated isoprene-based polymer, and a hydrogenated butadiene-based polymer. These polymers may contain a repeating unit of another component such as a copolymer, but at least 50% of a saturated hydrocarbon-based unit may be contained.
As described above, it is important that the content is preferably 70% or more, more preferably 90% or more, so as not to impair the characteristic of the saturated hydrocarbon system having a low water absorption.

The molecular weight of the polymer of the component (A) in which the main repeating unit constituting the main chain is a saturated hydrocarbon-based unit is, for example, a number-average molecular weight (M
n) about 500 to 50,000, and even 1,000
~ 15,000, and a liquid material having fluidity at room temperature is preferable from the viewpoint of processability.

The alkenyl group introduced into the saturated hydrocarbon polymer is the same as in the case of the oxyalkylene polymer.

Accordingly, preferred specific examples of the polymer having at least one alkenyl group in the molecule and having a main repeating unit constituting a main chain of a saturated hydrocarbon as the component (A) include: A linear number average molecular weight (Mn) having two alkenyl groups at both ends is from 2,000 to 1
Examples thereof include a polyisobutylene-based, hydrogenated polybutadiene-based, and hydrogenated polyisoprene-based polymer having a molecular weight of 5,000 and an Mw / Mn of 1.1 to 1.2.

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. After curing, a large amount of hydrosilyl groups easily remain in the cured product and cause voids and cracks. Therefore, the number of hydrosilyl groups contained in the molecule is preferably 50 or less. Further, the number is preferably 2 to 30, more preferably 2 to 20, from the viewpoint of control of rubber elasticity and storage stability of the cured product. Further, in order to easily prevent foaming during curing, 20 In the following, from the viewpoint that curing failure does not easily occur even when the hydrosilyl group is deactivated, three are preferable, and the most preferable range is 3 to 20.

In the present invention, the hydrosilyl group is
The term “having one” means having one H bonded to Si. In the case of SiH ₂ , it has two hydrosilyl groups, but the H bonded to Si is harder to bond to different Si. And also preferable from the viewpoint of rubber elasticity.

The molecular weight of the component (B) is 30,000 as a number average molecular weight (Mn) from the viewpoint of dispersibility and roller workability when a conductivity imparting agent (component (D)) described later is added.
Or less, more preferably 20,000 or less,
In particular, 15,000 or less is preferable. Considering the reactivity and compatibility of the component (A), 300 to 10,000 is preferable.

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 from the viewpoint of compatibility with the components and availability, and α-methylstyrene-modified products are preferred from the viewpoint of storage stability.

The hydrosilylation catalyst as the component (C) is not particularly limited as long as it can be used as a hydrosilylation catalyst. Platinum simple substance, solid platinum supported on simple substance such as alumina, chloroplatinic acid (including complex such as alcohol), various complexes of platinum, chloride of metal such as rhodium, ruthenium, iron, aluminum, titanium, etc. No. 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 components (A) and (B) used in the curable composition as described above is such that the hydrosilyl group in the component (B) is 0.2 per mole of the alkenyl group in the component (A). -5.0 mol, more preferably 0.4-2.5 mol, from the viewpoint of rubber elasticity.

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.
0 ^-8 mol, more preferably 10 ^-1 to 10 ^-6 mol, especially 10 ^-3 mol
By using it in the range of from 10 to ⁶ mol, it is possible to make the reaction more efficient.

Further, the curable composition as described above has
If a conductive composition is obtained by adding a conductivity-imparting agent as the component (D), 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 of the compound include a compound that can impart conductivity. These conductivity imparting agents may be used alone or in combination of two or more.

It is preferable that the added amount of the conductivity-imparting agent as the component (D) is not more than 30% by weight based on the total amount of the components (A) to (C), from the viewpoint of not increasing the rubber hardness.
On the other hand, from the viewpoint of obtaining a uniform resistance, the content is preferably 10% by weight or more. The required rubber hardness and the volume resistivity of the cured product are 10 ³
The amount to be added may be determined from the balance of physical properties so as to be 10 to 10 ¹⁰ Ωcm, preferably 10 ⁴ 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.

The curable composition may contain a filler, a storage stabilizer, a plasticizer, an ultraviolet absorber, a lubricant, a pigment, and the like for improving processability and cost.

Next, a procedure for manufacturing an elastic developing roller using the molding apparatus A will be described with reference to FIG.

First, the lower core holding member 3 is mounted on the cylindrical mold 1, the core 4 is inserted from the upper opening side of the cylindrical mold 1, and one end thereof is inserted into the lower core holding member 3. It is inserted into the provided support hole 8. Next, while inserting the other end of the core 4 into the support hole 9 provided in the upper core holding member 2, the upper core holding member 2 is screwed and mounted on the cylindrical mold 1.

Next, an injection nozzle 6a for an elastic layer material is attached to the first injection hole 6 provided in the lower core holding member 3, and
The molding space 9 is filled with the elastic layer material while removing gas from the gas vent hole 5. Here, when the elastic layer material is mainly composed of a thermosetting resin, it is preferable to fill the upper surface with a gap of about 1 to 2 mm in consideration of thermal expansion due to heat curing.

Next, the filled elastic layer material is cured and shrunk to form the elastic layer 10. Here, when the elastic layer material is mainly composed of a thermoplastic resin, it is cooled and cured, and when the elastic layer material is mainly composed of a thermosetting resin, it is cured by heating. The cured elastic layer material contracts upon cooling,
A uniform gap 11 is formed between the outer peripheral surface of the elastic layer 10 and the inner peripheral surface of the cylindrical mold 1.

Next, an injection nozzle 7a for a surface layer material is mounted on the second injection hole 7 provided in the lower core holding member 3, and
The gap 11 is filled with a surface layer material. Then, the filled surface layer material is cured to form the surface layer 12.

The surface layer 12 formed by the above procedure
Is determined by the gap 11, and this gap 1
The width t of 1 is a contraction amount determined by a difference between a heat curing temperature and a cooling temperature according to a thermal expansion coefficient specific to the elastic layer material, a curing shrinkage ratio determined by an injection pressure at the time of material injection, and a thermal expansion determined by a thickness of the elastic layer. It can be controlled by the amount of contraction. For example, when the curable composition is used as an elastic layer material in the composition shown in Table 1 below, and a roller having an outer diameter of φ10 mm and an outer diameter of the elastic layer after molding shrinkage of φ15.96 mm is designed, In consideration of molding shrinkage, the inner diameter of the molding die is φ16.01 mm, and 25 μm between the die and the elastic layer.
Then, when the surface layer resin is injected into the gap, the thickness of the surface layer becomes 25 μm.

[0051]

[Table 1]

If the temperature at which the molded product is taken out is lower than the temperature inside the mold when the material for the surface layer is injected, the outer diameter of the molded product can be made smaller than the inner diameter of the mold, and the molded product can be easily taken out.

The method of manufacturing the elastic roller according to the present invention is not limited to the elastic developing roller by appropriately selecting the material to be used. Can be adopted.

[0054]

According to the manufacturing method of the present invention, the elastic layer and the surface layer can be continuously formed without taking out the molded product in the same mold, so that the manufacturing cost can be greatly reduced and uniformity without unevenness can be obtained. An elastic roller which can form a smooth surface layer and can maintain good image quality without blurring can be obtained.

When the molding apparatus of the present invention is used, the disadvantage that the elastic layer material is mixed in the surface layer can be avoided.
The physical properties of the surface layer are stable, and the charging characteristics and transportability of the developer can be accurately controlled.

[Brief description of the drawings]

FIG. 1 is a simplified sectional view showing a representative embodiment of a molding apparatus according to the present invention.

FIG. 2 is a simplified cross-sectional view showing a shaft in which a shaft and a roll are formed from a conductive resin.

FIG. 3 is a simplified sectional view showing a shaft obtained by inserting a metal shaft as a shaft into a conductive resin molded as a roll.

FIG. 4 is a view showing a first mounting through hole and a second mounting hole for both injecting a material and degassing the upper core holding member of the molding apparatus according to the present invention;
FIG. 4 is a simplified cross-sectional view showing a state in which a mounting through hole is provided.

FIG. 5 is a simplified cross-sectional view showing a state where an injection nozzle is mounted in the mounting through hole.

FIG. 6 is an explanatory view showing a typical embodiment of the manufacturing method according to the present invention.

FIG. 7 is a simplified sectional view showing a conventional molding apparatus.

[Explanation of symbols]

A Molding device 1 Cylindrical mold 2 Upper core holding member 3 Lower core holding member 4 Core 4a Shaft 4b Roll 5 Gas vent hole 6 First injection hole 6 'First mounting through hole 6a Injection nozzle 7th 2 injection hole 7 'second mounting through hole 7a injection nozzle 8 support hole 9 support hole 10 elastic layer 11 gap 12 surface layer 13 conductive resin layer 14 shaft t width k gap 50 molding device 51 cylindrical mold 52 upper core body Holding member 53 Lower core holding member 54 Core 55 Gas vent hole 56 Injection hole

Claims (4)

[Claims] When manufacturing an elastic roller comprising a core and a cylindrical elastic layer having a surface layer on the outer periphery, a core is fixed coaxially in a cylindrical mold, and then the cylindrical metal is fixed. A method for manufacturing an elastic roller, comprising: filling an elastic layer material in a mold, curing and contracting the elastic layer material, and then filling a gap created by the contraction with a surface layer material. 2. The polymer of (A) wherein the elastic layer material contains at least one alkenyl group in a molecule, and a repeating unit constituting a main chain mainly comprises an oxyalkylene unit or a saturated hydrocarbon unit; B) a curable composition comprising, as main components, a curing agent containing at least two hydrosilyl groups in a molecule, (C) a hydrosilylation catalyst, and (D) a conductivity-imparting agent. The method for manufacturing an elastic roller according to claim 1. 3. A metal shaft, a conductive resin shaft, or a shaft obtained by inserting a metal shaft into a conductive resin layer, as the core body. A manufacturing method of the elastic roller according to the above. 4. A molding apparatus for producing an elastic roller comprising a cylindrical elastic layer provided with a surface layer on the outer periphery and a core, and a core holding member for supporting both ends of the core, and a cylindrical member. A molding apparatus comprising: a mold; and a first injection hole for injecting an elastic layer material and a second injection hole for injecting a surface layer material, in the core holding member.