JP2011107262A - Elastic roller and method for manufacturing the same, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an elastic roller that prevents roughness formed by foam on a surface of a foam elastic layer, and by which roller high-quality electrophotographic images are formed. <P>SOLUTION: The method is used for manufacturing the elastic roller including: a shaft core 2; and the foam elastic layer 3 around the shaft core 2. The method includes: a step of forming a composite layer with a specific silicone oil, silicone gel agent, carbon black, and reactive catalyst around the shaft core; and a step of forming the foam elastic layer by making the composite layer freely foam and curing the composite layer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an elastic roller, a manufacturing method thereof, and an image forming apparatus.

  Patent Document 1 describes a method described below as a method for manufacturing an elastic roller having a foamed elastic layer used in an image forming apparatus using an electrophotographic method. First, an applicator is provided with a predetermined gap while rotating the roller base material, and the liquid raw material for silicone rubber foam is supplied to the gap between the applicator moving at a constant speed. Then, the roller base material is continuously rotated and foamed and cured. Patent Document 1 describes that according to this method, a sponge roller having a uniform structure with a constant film thickness can be obtained and can be suitably used as a paper feed roller or a cleaning roller.

Japanese Patent Laid-Open No. 7-76049

  However, according to the study by the present inventors, it has been found that the manufacturing method of Patent Document 1 has the following problems. That is, when free foaming of a liquid material for silicone foam by dehydrogenation reaction, the material viscosity is low with respect to the pressure generated by foaming, and there is nothing that suppresses the formation of bubbles by the foaming reaction. Easy to grow. As a result, an uneven surface due to bubbles may be formed on the surface of the foamed elastic layer. In addition, bubbles may be exposed on the surface of the foamed elastic layer, and a smooth surface may not be obtained. If there are irregularities larger than the particle size of the toner on the surface of the conductive roller such as a developing roller or a charging roller, it may affect the uniform transportability of the toner and the uniform chargeability of the photoreceptor. Even when a surface layer is provided on the peripheral surface of the foamed elastic layer, non-uniform exposure of bubbles to the surface of the foamed elastic layer is a problem to be solved in order to obtain a smooth surface.

  Accordingly, an object of the present invention is to control foaming when forming a foamed elastic layer by free foaming, thereby providing a conductive material that has a foamed elastic layer having a uniform surface and can be used to form a high-quality electrophotographic image. It is in providing the manufacturing method of a roller.

  Another object of the present invention is to provide a conductive roller suitably used as a developing roller and an image forming apparatus that provides a high-quality electrophotographic image.

  The present inventors have intensively studied to solve this problem. As a result, a silicone gelling agent is added to the liquid silicone foam raw material, and the gelated layer is formed around the shaft core body, and then foamed and cured to form a silicone foamed elastic layer. It has been found that the above problems can be solved.

The method for producing an elastic roller according to the present invention is a method for producing an elastic roller having a shaft core and a foamed elastic layer around the shaft core,
(1) forming a layer of a mixture containing the following (A) to (F) around the shaft core;
(2) having a step of free-foaming and curing the mixture layer to form a foamed elastic layer:
(A) a silicone oil containing a silicon atom-bonded vinyl group in the molecule;
(B) a silicone oil containing a silicon atom-bonded hydroxyl group in the molecule;
(C) a silicone oil containing silicon-bonded hydrogen atoms in the molecule,
(D) silicone gelling agent,
(E) Carbon black,
(F) Reactive catalyst.

  The elastic roller according to the present invention is manufactured by the above method. Furthermore, an image forming apparatus according to the present invention includes the above-described elastic roller as a developing roller.

  According to the present invention, it is possible to obtain an elastic roller that has a foamed elastic layer having a fine, uniform and smooth surface and can be suitably used for a developing roller and a charging roller.

It is a perspective view of the elastic roller which concerns on this invention. 1 is a cross-sectional view of an image forming apparatus according to the present invention. It is explanatory drawing of the shaping | molding method of an elastic roller.

  Hereinafter, the present invention will be described in detail. In the production method of the present invention, at least the following (A) to (F) are mixed, an unreacted silicone rubber layer is formed around the shaft core, and then foamed and cured to form a foamed elastic layer.

The present invention includes (1) a step of forming a mixture layer containing the following (A) to (F) around the shaft core, and (2) free foaming and curing the mixture layer to form a foamed elastic layer. Forming with:
(A) a silicone oil containing a silicon atom-bonded vinyl group in the molecule;
(B) a silicone oil containing a silicon atom-bonded hydroxyl group in the molecule;
(C) a silicone oil containing silicon-bonded hydrogen atoms in the molecule,
(D) silicone gelling agent,
(E) Carbon black,
(F) Reactive catalyst.

  In the present invention, free foaming is not foaming in a closed space such as in a mold but foaming in an open space. That is, the surface of the layer to be foamed is exposed to the outside air and is not restricted by the inner wall of the mold. Therefore, large bubbles are easily exposed on the surface of the foamed elastic layer, and a foaming roller having poor surface smoothness is easily formed. However, according to the present invention, it is difficult for the foaming gas to escape from the inside of the layer to be foamed by using the silicone gelling agent, so that the bubbles are difficult to be exposed on the surface.

<(A) component>
The component (A) is a silicone oil containing a silicon atom-bonded vinyl group in the molecule and is a main material in the production method of the present invention. This silicone oil is preferably mainly one in which both ends of the molecular chain are blocked with vinyl groups. Further, those having a polymerization degree of 50 to 3000 are preferably used.

  Examples of the silicone oil side chain of the component (A) include a substituted or unsubstituted monovalent saturated hydrocarbon group that does not have an aliphatic unsaturated bond such as a vinyl group. Specific examples of the saturated hydrocarbon group are given below. Alkyl group (methyl group, ethyl group, propyl group, etc.), cycloalkyl group (cyclohexyl group, etc.), aryl group (phenyl group, tolyl group, etc.), aralkyl group (benzyl group, 2-phenylethyl group, 2-phenylpropyl) Group). Among these, a methyl group is preferable as the side chain. The main chain structure of the component A is, for example, a dimethylsiloxane structure.

<(B) component>
Component (B) is a silicone oil containing a silicon atom-bonded hydroxyl group in the molecule, and is a component necessary for appropriately foaming the composition and obtaining a silicone foam. The silicone oil as component (B) is preferably mainly composed of both molecular chain ends blocked with hydroxyl groups. Further, those having a polymerization degree of 5 to 2000 are preferably used. Examples of the silicone oil side chain of component (B) include substituted or unsubstituted monovalent saturated hydrocarbon groups, such as alkyl groups such as methyl, ethyl, and propyl groups; cycloalkyl groups such as cyclohexyl groups. Aryl groups such as phenyl groups; aralkyl groups and the like. Among these, a methyl group is preferable. The main chain structure of the B component is, for example, a dimethylsiloxane structure.

  In order to impart mechanical strength to the silicone foam, the polymerization degree of the component (B) is preferably 50 to 1000. (B) It is suitable that the compounding quantity of a component is 0.1-50 mass parts with respect to 100 mass parts of silicone oils of the said (A) component.

<(C) component>
The component (C) is a silicone oil containing silicon-bonded hydrogen atoms in the molecule. The hydrogen atom bonded to the silicon atom undergoes an addition reaction with the vinyl group of the silicone oil of component (A) to form a rubber-like cured product. Further, hydrogen gas is generated by dehydrogenation reaction with the hydroxyl group of the silicone oil as component (B). Thereby, foaming and curing proceed simultaneously to obtain a silicone foam. The component (C) is preferably a silicone oil having two or more silicon-bonded hydrogen atoms in one molecule. Examples of the silicone oil side chain of component (C) include substituted or unsubstituted monovalent saturated hydrocarbon groups, such as alkyl groups such as methyl, ethyl, and propyl groups, cycloalkyl groups, aryl groups, And aralkyl groups. Of these, a methyl group is preferred. The molecular structure of the component (C) may be one in which a hydrogen atom is bonded to a silicon atom at the end of the molecular chain, or may be bonded to a silicon atom other than the molecular chain end. A straight chain, cyclic or branched siloxane skeleton may be used, but a straight chain is preferred for ease of synthesis. In order to obtain a foam having excellent mechanical strength, the component (C) preferably has a branched chain structure. The addition amount of the component (C) is such that the hydrogen atom bonded to the silicon atom in the component (C) is the total number of moles of the vinyl group in the component (A) and the hydroxy group in the component (B). It is preferably used in an amount of 2 to 40 mol. By setting the hydrogen atom bonded to the silicon atom of component (C) to an amount that is 2 mol or more, the composition is sufficiently easily foamed. Moreover, it becomes easy to prevent problems, such as a physical property fall of the hardened | cured material (foam) obtained by setting it as 40 mol or less, and a foam to become hard with time.

<(D) component>
The component (D) is a silicone gelling agent that can gel the silicone oils (A) to (C). The silicone gelling agent is a component that is swollen by the silicone oil according to the above (A) to (C), includes the above (A) to (F), and forms a gel substance having a thixotropic property. The gel-like substance has low fluidity, suppresses release of hydrogen gas to the atmosphere due to a dehydrogenation reaction during free foaming, and suppresses bubble growth. Since the curing reaction also proceeds in this state, a silicone foam roller having a fine and uniform cell diameter and excellent surface smoothness can be obtained.
The component (D) has a three-dimensional structure represented by the following formula (I) in the molecule, exhibits liquid or pasty properties at room temperature, and easily causes plastic deformation due to external stress. An organopolysiloxane crosslinked product is particularly preferably used. This is because the ability to swell and gel in silicone oil is high.

  In the above formula (I), R1 to R6 each independently represent a hydrogen atom or a methyl group. Such an organopolysiloxane cross-linked product is obtained by hydrosilylating a silicone oil having two or more silicon atoms-bonded vinyl groups in a side chain and a silicone oil having two or more silicon atoms-bonded hydrogen atoms using a reactive catalyst. Obtained by carrying out the reaction. The molecular structure of a silicone oil containing a silicon atom-bonded vinyl group in the side chain (hereinafter also referred to as vinyl group-containing silicone oil) may be linear, branched, or network. The polymerization degree of the vinyl group-containing silicone oil for forming a crosslinked product is preferably 50 to 3000. This is because by setting the degree of polymerization to 50 or more, the volatility is lowered and the composition is easily stabilized. Moreover, it is because it is easy to raise | generate uniform and sufficient crosslinking reaction by making a polymerization degree into 3000 or less. The vinyl group content is preferably 0.3 to 2.0% by mass in one molecule. It is because it is easy to make the oil separation degree of the obtained paste-like silicone composition small by setting it as 0.3 mass% or more. Moreover, it is because it is easy to make it into a paste form by making a crosslinking density into a suitable range by setting it as 2.0 mass% or less. Examples of the molecular chain end group of the vinyl group-containing silicone oil for forming a crosslinked product include a trimethylsiloxy group and a dimethylvinylsiloxy group.

  The blending amount of the silicone oil having two or more silicon atom-bonded hydrogen atoms with respect to the vinyl group-containing silicone oil is such that the silicon atom-bonded hydrogen atoms average 0.3 to 3 per mole of vinyl groups of the vinyl group-containing silicone oil. The amount is preferably 0 mol. This is because the crosslinking proceeds smoothly, the silicone oil is easily taken into the molecular structure, and the gelation effect is further enhanced. Moreover, it is because a crosslinking density does not become too high, and the “consistency” described later can be set to an appropriate value.

  In addition, the crosslinked organopolysiloxane as the component (D) is [INCI name: Dimethicone / Vinyl Dimethicone Crosspolymer, display name: (dimethicone / vinyl dimethicone) crosspolymer], or crosslinked methylphenylpolysiloxane [INCI name: Dimethicone]. / Phenyl Vinyl Dimethicone Crosspolymer, Display Name: (Dimethicone / Phenyl Dimethicone) Cross Polymer] is commercially available for cosmetic use.

  Furthermore, what made the moderate paste-form composition by adding low-viscosity silicone oil to said organopolysiloxane crosslinked material, and making it swell can be used as a gelatinizer (D) component. A paste in which the cross-linked polysiloxane is mixed with a low-viscosity silicone oil in this way is also commercially available. Commercially available products include KSG-15 (a mixture of 4 to 10% cross-linked methylpolysiloxane and 90 to 96% decamethylcyclopentasiloxane) from Shin-Etsu Chemical Co., Ltd., and KSG-16 (20 to 20 cross-linked methylpolysiloxane). 30% and a mixture of methylpolysiloxane 70 to 80%) and KSG-18 (a mixture of crosslinked methylphenylpolysiloxane 10 to 20% and methylphenylpolysiloxane 80 to 90%).

  The degree of cross-linking of the siloxane cross-linked product in the present invention can be expressed by “Consistency” of Japanese Industrial Standard (JIS) K2220. Consistency is the apparent hardness of the paste-like substance, and is a numerical value representing the depth of penetration of the specified cone into the sample by 10 times mm. And this "consistency" 20-150 can be used suitably as a gelatinizer. By setting the “consistency” within the above range, the silicone oils (A) to (C) can be sufficiently mixed and a sufficient gelling effect can be obtained. The crosslinked organopolysiloxane in the present invention has almost no rubber elasticity.

  (D) It is preferable that the addition amount of a component is 10-70 mass parts with respect to 100 mass parts of (A) component. By setting it as 10 mass parts or more, thixotropic property can be expressed more effectively and it is easy to produce a thickening effect more effectively. As a result, it is possible to obtain a developing roller having a sufficiently smooth surface by suppressing the bubble formation due to the foaming reaction in the process of free foaming, suppressing the bubble diameter from excessively increasing and preventing bubble breakage. Moreover, by setting it as 70 mass parts or less, the quantity of a foaming material can be reduced relatively, sufficient foaming is obtained over the whole roller, and it becomes easy to prevent generation | occurrence | production of foam uneven distribution. Moreover, the mixture of (A)-(F) can express a thixotropic property more effectively. Therefore, since the material viscosity increases, it functions to suppress bubble formation due to the dehydrogenation reaction. Since the curing reaction is promoted in this state, it is possible to obtain a conductive silicone foam roller having a fine skin diameter and a uniform skin layer.

  The specific gravity of the conductive silicone foam roller obtained here is preferably 0.3 to 0.7. When the specific gravity is 0.3 or more, it is possible to have a skin layer having a fine and uniform bubble diameter, and thus it is possible to suppress variations in hardness and conductivity. When the specific gravity is 0.7 or less, the flexibility which is a characteristic of the silicone foam roller can be obtained. Here, the specific gravity can be measured based on the provisions of Japanese Industrial Standard (JIS) K6268 (Measurement of Density of Vulcanized Rubber). Examples of the measuring device include an automatic hydrometer (trade name: DMA-220H, manufactured by Shinko Denshi Co., Ltd.).

<(E) component>
The component (E) is carbon black for imparting conductivity to the silicone foam roller. As carbon black, what is normally used for the conductive rubber composition can be used. Examples thereof include acetylene black, furnace black, channel black, and thermal black. The addition amount of the conductive carbon black is preferably 3 to 50 parts by mass, and more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the component (A). By making the addition amount 3 parts by mass or more, desired conductivity can be easily obtained. Moreover, it becomes easy to prevent impairing the mechanical characteristics of a roller by setting it as 50 mass parts or less.

<(F) component>
(F) component cures the foaming material by an addition reaction between the vinyl group in component (A) and the hydrogen atom bonded to the silicon atom in component (C), and the hydrogen atom and component (B) It is a catalyst which accelerates | stimulates dehydrogenation reaction between the hydroxyl groups. Examples of the component (F) include platinum compounds such as chloroplatinic acid, complexes obtained from alcohol and chloroplatinic acid, platinum olefin complexes, platinum ketone complexes, and platinum vinylsiloxane complexes. The content of the component (F) is not particularly limited and can be appropriately selected in consideration of the function as a catalyst. For example, the content of the component (A) is 0.1 to 1000 ppm in terms of platinum atoms. Is usually used, and preferably 0.5 to 200 ppm. By setting it to 0.1 ppm or more, the catalyst concentration does not become too low, and the curing reaction can be promoted more effectively. Moreover, it can prevent adding more than needed by setting it as 1000 ppm or less, and is preferable from an economical viewpoint.

<Other ingredients>
In order to improve the storage stability at room temperature of the system in which the component (F) is blended, a reaction inhibitor may be blended to control the dehydrogenation reaction at a high temperature. Examples of reaction inhibitors include acetylene alcohol (3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, etc.) and alkynyloxy group-containing silicon compounds (dimethylbis (1,1- Dimethylpropyne-2-oxy) silane and the like. As long as the object of the present invention is not impaired, the mixture containing (A) to (F) is optionally mixed with silica, quartz powder, diatomaceous earth, aluminum oxide, zinc oxide, iron oxide, cerium oxide, mica, clay. In addition, fillers and pigments such as calcium carbonate and graphite can be blended.

  Hereinafter, although embodiment of this invention is described, it is not limited in particular to the following embodiment. First, as a silicone foam material, a master batch is prepared in advance by blending the component (A) with the component (E) and, if necessary, a filler. A mixture of this master batch and the components (B), (D), and (F) is designated as A liquid. Separately, a mixture of the master batch and the component (C) is designated as B liquid. In this way, two liquid silicone foam materials (A liquid and B liquid) are prepared. The preparation temperature is not particularly limited as long as it does not cause curing or generation of hydrogen gas, but is generally 0 to 50 ° C., preferably 5 to 30 ° C. in consideration of workability.

  FIG. 1 shows a perspective view of an example of a conductive roller. In FIG. 1, 2 is a shaft core. In the conductive silicone foam roller, a conductive silicone foam layer 3 containing carbon black is provided around the shaft core body 2, and a conductive resin layer 4 made of a thin layer of conductive resin is further formed thereon. It is covered. The shaft core 2 functions as an electrode and a support member of the conductive roller 1. The shaft core body 2 is made of, for example, a metal or alloy such as aluminum, copper alloy, or stainless steel, iron plated with chromium, nickel, or synthetic resin. The shape is preferably a columnar shape or a cylindrical shape with a hollow center. The outer diameter of the shaft core body can be determined as appropriate, but it is usually preferably in the range of 4 mm to 20 mm.

  An example of an electrophotographic process cartridge and an image forming apparatus mounted as a developing roller according to the present invention is shown in FIG. It is shown in FIG.

The image forming apparatus includes four image forming units 10a to 10d for forming yellow, cyan, magenta, and black images, which are provided in tandem. Each image forming unit includes a photosensitive drum 11, a charging device 12 (charging roller), an image exposure device 13 (writing beam), a developing device 14, a cleaning device 15, an image transfer device 16 (transfer roller), and the like. The photosensitive drum 11, the charging device 12, the developing device 14, and the cleaning device 15 are integrated to form a process cartridge that can be attached to and detached from the main body of the image forming apparatus.
The developing device 14 includes a developing container 6 that stores the one-component toner 5 and a developing roller 1 that is located in an opening extending in the longitudinal direction in the developing container 6 and is disposed to face the photosensitive drum 11. The electrostatic latent image on the drum 11 is developed and visualized. Further, the developing device 14 is provided with a toner supply roller 7 and a developing blade 8. The toner supply roller 7 supplies the one-component toner 5 to the developing roller 1 and scrapes off the one-component toner 5 carried on the developing roller 1 without being used for development. The developing blade 8 regulates the carrying amount of the one-component toner 5 on the developing roller 1 and is frictionally charged.

  First, the surface of the photosensitive drum 11 is uniformly charged to a predetermined polarity and potential by the charging device 12, and image information is irradiated as a beam from the image exposure device 13 to the surface of the charged photosensitive drum 11, thereby An image is formed. Next, a one-component toner is supplied in a layer form from the developing device 14 that uses the conductive roller using the silicone foam roller of the present invention as the developing roller 1 on the formed electrostatic latent image. The supplied toner is formed as a toner image on the surface of the photosensitive drum 11, and the electrostatic latent image is visualized. As the photosensitive drum 11 rotates, the toner image is transferred to a transfer material 25 such as paper that is supplied in synchronization with the rotation when the toner image comes to a position facing the image transfer device 16.

  In the drawing, four image forming units 10 a to 10 d are formed in a series of interlocking manner so that predetermined color images are superimposed on one transfer material 25. Therefore, the transfer material 25 is synchronized with the image formation of each image forming unit, that is, the image formation is synchronized with the insertion of the transfer material 25. For this purpose, the transfer roller 17 for transporting the transfer material 25 is sandwiched between the photosensitive drum 11 and the image transfer device 16 so that the drive roller 18, the tension roller 19, and the driven roller 20 of the transfer conveyor belt 17. It is laid around. Further, the transfer material 25 is conveyed in a form that is electrostatically adsorbed to the transfer conveyance belt 17 by the action of the adsorption roller 21. Reference numeral 22 denotes a supply roller for supplying the transfer material 25. The transfer material 25 on which the image has been formed is peeled off from the transfer conveyance belt 17 by the action of the peeling device 23 and sent to the fixing device 24, and the toner image is fixed on the transfer material 25 to complete the printing. On the other hand, the photosensitive drum 11 after the transfer of the toner image to the transfer material 25 is further rotated, and the surface of the photosensitive drum 11 is cleaned by the cleaning device 15 and is neutralized by a neutralizing device (not shown) as necessary. Thereafter, the photosensitive drum 11 is used for the next image formation. In the figure, reference numerals 26 and 27 denote bias power supplies to the image transfer device 16 and the suction roller 21, respectively.

  Here, the apparatus for directly transferring the toner image of each color onto the tandem type transfer material has been described. However, any apparatus that uses the conductive roller of the present invention as the developing roller may be used. For example, monochrome monochrome image forming apparatuses, image forming apparatuses that form color images by superimposing each color toner image on a transfer roller or transfer belt, and then transferring them all at once to a transfer material, each color developing unit being arranged on a rotor, or photosensitive Examples thereof include an image forming apparatus arranged in parallel with a drum. Further, instead of the process cartridge, a photosensitive drum, a charging device, a developing device, and the like may be directly incorporated in the image forming apparatus.

(Example)
Examples of the present invention will be described in detail below. In addition, this invention is not limited to a following example.

(Preparation of crosslinked organopolysiloxane)
<Preparation of gelling agent 1>
The materials shown in Table 1-1 below were mixed and uniformly mixed for 2 hours with a planetary mixer adjusted to 70 ° C. to prepare a silicone composition. The obtained silicone composition was vacuum degassed and then heated at 70 ° C. for 30 minutes to obtain a silicone gel (gelling agent 1). The “consistency” of the gelling agent 1 was measured as follows. 40 ml of the gelling agent 1 was put in a heat-resistant glass beaker having a capacity of 50 ml and cured by heating in a hot air dryer at 100 ° C. for 60 minutes to obtain a silicone gel. After cooling to room temperature (23 ° C.), the immiscible consistency was measured based on “Consistency Test Method” of Japanese Industrial Standard (JIS) K2200 (grease). A 1/4 cone was used for the measurement. The temperature in the test chamber was 23 ° C. As a result, the consistency of the gelling agent 1 was 50.

<Preparation of gelling agent 2>
The materials shown in Table 1-2 below were mixed and a silicone gel (gelator 2) was prepared in the same manner as in Preparation-1. The consistency of the gelling agent 2 was 72.

<Preparation of gelling agent 3>
The materials shown in Table 1-3 below were mixed to prepare a silicone gel (gelator 3) in the same manner as in Preparation-1. The consistency of the gelling agent 3 was 68.

<Preparation of gelling agent 4>
The materials shown in Table 1-4 below are mixed to obtain a silicone gel (gelator 4) in the same manner as in Preparation-1. The consistency of the gelling agent 4 was 106.

<Preparation of gelling agent 5>
The materials shown in Table 1-5 below were mixed, and a silicone gel (gelator 5) was prepared in the same manner as in Preparation-1. The consistency of the gelling agent 5 was 87.

<Preparation of base material>
The following materials were blended and mixed with a planetary mixer for 1 hour to form a liquid silicone rubber base material.
-(A) component: Polydimethylsiloxane blocked with both terminal vinyl groups with a polymerization degree of 500; 100 parts by mass; (E) component; Denka black (acetylene black, average particle size 40 nm, Denki Kagaku Kogyo Co., Ltd.); 7.0 Part by mass [Example 1]
<Liquid A>
A liquid obtained by mixing the materials shown in Table 2-1 below with a planetary mixer for 30 minutes was used.

<Liquid B>
A liquid B was prepared by mixing the materials shown in Table 2-2 below with a planetary mixer for 30 minutes.

<Formation of conductive silicone foam roller>
Said A liquid and B liquid were stored in the material tank 1 of the ring coat machine shown in FIG. A shaft core body holding shaft 32 produced by applying nickel plating (Ni) to an iron shaft core body (SUM material) having an outer diameter of φ6 mm was set vertically on a ring coater. Thereafter, the shaft core body was moved by vertically raising the shaft core body holding shaft (60 mm / sec). The A liquid and the B liquid passed through the static mixer 33, were supplied to the ring head 34, and were supplied to the outer periphery of the shaft core body. The supplied mixture of liquid A and liquid B formed an uncured silicone rubber composition layer on the outer periphery of the shaft core. In this way, a roll having an uncured silicone rubber composition layer (hereinafter, uncured roll 35) was produced. The obtained uncured roll 35 is rotated around the shaft core, and infrared light (output: 1000 W) is applied to the surface of the uncured silicone rubber composition layer with an infrared heating lamp “HYL25” (trade name) manufactured by Hibeck Co., Ltd. Was irradiated for 2 minutes to foam and cure. The distance between the surface of the silicone rubber composition layer and the lamp during infrared irradiation was 60 mm, and the temperature of the surface of the silicone rubber composition layer was 100 ° C. Then, in order to stabilize the physical properties of the elastic layer of the cured silicone rubber, secondary curing was performed at 200 ° C. for 4 hours in an electric furnace to obtain a conductive silicone foam roller having a diameter of 12 mm.

<Production of elastic roller for image evaluation>
MEK was added to the materials shown in Table 2-3 below and dispersed with a sand mill for 1 hour. After dispersion, MEK was further added and adjusted so that the film thickness after coating and drying became 10 μm in the range of 20% by mass to 30% by mass of the solid content to obtain a coating material for the surface layer.

The surface layer paint was spray-coated on the surface of the obtained conductive silicone foam roller, and then naturally dried. Next, heat treatment was performed at 140 ° C. for 60 minutes to cure the paint film, and an elastic roller for image evaluation having a surface layer formed thereon was obtained.
<Specific gravity measurement of elastic layer of roll for image evaluation>
1 cm3 of the elastic layer of the roll for image evaluation was cut out with a knife, and the specific gravity was measured using an automatic specific gravity measuring device (trade name: DMA220H, manufactured by Shinko Denshi Co., Ltd.). As measurement conditions, the sample immersion time was 5 seconds, and the measurement temperature was 23 ° C.

<Evaluation of image characteristics of roll for image evaluation>
The image evaluation roll was mounted as a developing roll on a process cartridge (A4 size) of an image forming apparatus (trade name: LBP5050; manufactured by Canon Inc.) This process cartridge was filled with cyan toner.

(Evaluation of the effect of bubbles)
The process cartridge was left in an environment of a temperature of 23 ° C. and a humidity of 55% RH for 24 hours, and then loaded into the image forming apparatus, and a solid image and a halftone image were output in an environment of a temperature of 23 ° C. and a humidity of 55% RH. White spots on the output image were observed. Separately, the image forming apparatus in the middle of output was stopped halfway, and the toner state on the surface of the photosensitive drum was observed to evaluate the influence of bubbles of the silicone foam.

A: No missing toner is observed on the photosensitive drum, and no white spots are observed on the image.
B: Omission of toner is observed on the photosensitive drum, but no spots are observed on the image.
C: White spots are observed on the image.

(Evaluation of current leak image)
The process cartridge was left in an environment of a temperature of 23 ° C. and a humidity of 55% RH for 24 hours, and then incorporated into an image forming apparatus. Using the image forming apparatus, a solid image and a halftone image were output under a normal environment of 23 ° C. and 55% RH. At this time, the difference Δ between the voltage applied to the developing roll (−250V) and the voltage applied to the developing blade (−450V) was set to 200V.

Next, the voltage applied to the developing blade was set to −650 V (Δ400 V), an image was output in a situation where current leakage was likely to occur, and the presence or absence of current leakage was evaluated by the image.
A: No current leak is observed in normal image output and image output at Δ400V.
B: Observed in image output at Δ400V, but no current leakage is observed in normal image output.
C: Current leakage is observed during normal image output.

[Example 2]
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component of <A liquid> in Example 1 was changed to the following.
B component: a silicone oil containing hydroxyl groups at both ends with a polymerization degree of 10; 8 parts by mass.

Example 3
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the addition amount of the gelling agent 1 as the D component in the <Component A> of Example 1 was changed to 9 parts by mass.

Example 4
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: a silicone oil containing hydroxyl groups at both ends with a degree of polymerization of 10; 10 parts by mass.
-D component: Gelling agent 2; 10 mass parts.

Example 5
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: a silicone oil containing hydroxyl groups at both ends with a degree of polymerization of 10; 10 parts by mass.
-D component: Gelling agent 2; 70 mass parts.

Example 6
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
-B component: Silicone oil containing hydroxyl groups at both ends with a degree of polymerization of 10; 6 parts by mass.
-D component: Gelling agent 2; 10 mass parts.

Example 7
An image evaluation roll was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
-B component: Both ends hydroxyl group containing silicone oil whose polymerization degree is 10; 6 mass parts.
-D component: Gelling agent 2; 70 mass parts.

Example 8
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: a silicone oil containing hydroxyl groups at both ends with a polymerization degree of 10; 8 parts by mass.
-D component: Gelling agent 3; 9 mass parts.

Example 9
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: a silicone oil containing hydroxyl groups at both ends with a polymerization degree of 10; 8 parts by mass.
-D component: Gelling agent 3; 72 mass parts.

Example 10
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: a silicone oil containing hydroxyl groups at both ends with a degree of polymerization of 10; 12 parts by mass.
-D component: Gelling agent 3; 9 mass parts.

Example 11
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: a silicone oil containing hydroxyl groups at both ends with a degree of polymerization of 10; 5 parts by mass.
-D component: Gelling agent 3; 72 mass parts.

Example 12
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
-B component: Hydroxyl group-containing silicone oil having a degree of polymerization of 10; 8 parts by mass-D component: Gelling agent 3; 40 parts by mass.

Example 13
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: Silicone oil containing hydroxyl groups at both ends with a degree of polymerization of 10; 12 parts by mass.
D component: Gelling agent 3; 40 mass parts.

Example 14
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: Silicone oil containing hydroxyl groups at both ends with a polymerization degree of 10; 5 parts by mass.
D component: Gelling agent 3; 40 mass parts.

Example 15
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: Silicone oil containing hydroxyl groups at both ends with a polymerization degree of 10; 10 parts by mass.
D component: Gelling agent 4; 10 mass parts.

Example 16
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: Silicone oil containing hydroxyl groups at both ends with a polymerization degree of 10; 10 parts by mass.
D component: Gelling agent 4; 70 mass parts.

Example 17
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: Hydroxyl group-containing silicone oil having a polymerization degree of 10; 6 parts by mass D component: Gelling agent 4; 10 parts by mass.

Example 18
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: hydroxyl group-containing silicone oil having a polymerization degree of 10; 6 parts by mass D component: gelling agent 4; 70 parts by mass.

Example 19
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: hydroxyl group-containing silicone oil having a polymerization degree of 10; 8 parts by mass D component: gelling agent 5; 40 parts by mass.

Example 20
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: hydroxyl group-containing silicone oil having a polymerization degree of 10; 5 parts by mass D component: gelling agent 5; 40 parts by mass.

Example 21
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: hydroxyl group-containing silicone oil having a degree of polymerization of 10; 8 parts by mass D component: gelling agent 5; 72 parts by mass.

[Example 22]
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
Component B: hydroxyl group-containing silicone oil having a degree of polymerization of 10; 12 parts by mass D component: gelling agent 1; 9 parts by mass.

Example 23
An elastic roller for image evaluation was prepared and evaluated in the same manner as in Example 1 except that the B component and D component in <A liquid> of Example 1 were changed to the following.
B component: hydroxyl group-containing silicone oil having a polymerization degree of 10; 5 parts by mass D component: gelling agent 5; 72 parts by mass.

[Comparative Example 1]
An elastic roller for image evaluation was produced and evaluated in the same manner as in Example 1 except that the gelling agent 1 as the D component in the <A solution> of Example 1 was not added.

DESCRIPTION OF SYMBOLS 1 Developing roller 2 Shaft core body 3 Conductive silicone foam layer 4 Conductive resin layer

Claims (3)

A method for producing an elastic roller having a shaft core and a foamed elastic layer around the shaft core,
(1) forming a layer of a mixture containing the following (A) to (F) around the shaft core;
(2) forming a foamed elastic layer by free-foaming and curing the layer of the mixture, and a method for producing an elastic roller, comprising:
(A) a silicone oil containing a silicon atom-bonded vinyl group in the molecule;
(B) a silicone oil containing a silicon atom-bonded hydroxyl group in the molecule;
(C) a silicone oil containing silicon-bonded hydrogen atoms in the molecule,
(D) silicone gelling agent,
(E) Carbon black,
(F) Reactive catalyst.   An elastic roller manufactured by the manufacturing method according to claim 1.   An image forming apparatus comprising the elastic roller according to claim 2 as a developing roller.