JP4931120B2 - Method for producing elastic roller - Google Patents

Description

The present invention relates to a method for manufacturing an elastic roller, and more particularly, to an elastic roller that can be used in, for example, an image forming apparatus and contributes to high definition of an image and improvement in durability of the image forming apparatus, and a method for manufacturing the same. .

  Various types of image forming apparatuses using an electrophotographic system are employed in laser printers, copiers, video printers, facsimiles, and complex machines of these. An image forming apparatus using an electrophotographic system includes a shaft body and an elastic layer formed on an outer peripheral surface thereof, for example, a cleaning roller, a charging roller, a developing roller, a transfer roller, a pressure roller, a paper feed conveyance roller, Various rollers such as a fixing roller are provided.

Among these rollers, for example, a cleaning roller, a paper feed / conveying roller, a fixing roller, and the like reduce the hardness of the elastic layer and improve the function of each roller. In order to form a high-definition image and improve its durability by fixing the developer as desired, cells may be formed in the elastic layer. As an index for evaluating whether or not a roller provided with an elastic layer (sometimes referred to as a foamed elastic layer) in which cells are formed exhibits the required functions and characteristics, Asker C hardness is given. It is done. For example, as an elastic roller provided with a foamed elastic layer having a specific Asker C hardness, Patent Document 1 describes, “In a fixing pressure roller in which a silicone rubber-like elastic body is provided on the outer periphery of a cylindrical metal core, It is made of a rubber-like elastic silicone rubber and has an open cell (hereinafter referred to as open cell) structure in which the water absorption is 40% or more and the open cell rate of 90% or more is 90% or more. "The hardness of the rubber-like foamed elastic body is 30 ° to 60 ° (Asker C)" in the "Pressure roller for fixing the rubber-like foamed elastic body characterized by" (Refer item 1 and claim 3 etc.). Patent Document 2 discloses that “a heating roll and a pressure roll that pressurizes the heating roll have an elastic layer, and the elastic layer has a thickness of 6 mm or more. And the hardness is 45 ° or less in Asker C, and the pressure applied to the heating roll is set to 9 N / cm ² or less. It consists of a body "(see claims 1 and 4 of patent document 2).

  This Asker C hardness is an index that represents the hardness of the foamed elastic layer in the vicinity of the surface, for example, a depth of about 5 mm from the surface. When the Asker C hardness was adjusted to a specific value, the foamed elastic layer could often exhibit the required functions or characteristics.

  However, in recent image forming apparatuses with high definition and high speed, even if the Asker C hardness in the vicinity of the surface of the foamed elastic layer is adjusted to a specific value, the function or characteristic required for the foamed elastic layer is sufficient. It is no longer possible to demonstrate it. In other words, in order for various rollers provided in recent image forming apparatuses to exhibit desired functions or characteristics, in addition to the characteristics of the foamed elastic layer in the vicinity of the surface, the characteristics of the entire foamed elastic layer are also important. It is coming. For example, in the case of a fixing roller, even if the foamed elastic layer has a desired Asker C hardness, the developer cannot be fixed as desired over a long period of time. In some cases, it was not possible to contribute to improving the durability of the forming apparatus.

Japanese Patent Laid-Open No. 2004-070159 JP 2004-287275 A

An object of the present invention is to provide an elastic roller that can be used in an image forming apparatus and the like, and that contributes to improving the durability of the image forming apparatus while forming a high-quality image, and a manufacturing method thereof.

As means for solving the problems,
Claim 1 is a method for producing an elastic roller having a foamed elastic layer in which the Asker C hardness and density satisfy the following relational expression , wherein the vinyl group-containing silicone raw rubber and silica-based rubber disposed on the outer peripheral surface of the shaft body An addition reaction type foamed silicone rubber composition containing a filler, a foaming agent, an addition reaction crosslinking agent, an addition reaction catalyst, and a reaction control agent is heated to 90 ° C. with a temperature rising time within 80 seconds, and then within 240 seconds. Is an elastic roller manufacturing method that heats up to 200 ° C. with a temperature rising time of
Claim 2 is a method for producing an elastic roller according to claim 1, wherein the rubber composition is further heated to a temperature sufficient for the foaming agent to decompose or foam.
According to a third aspect of the present invention, the addition reaction type foamed silicone rubber composition comprises the foaming agent in a proportion of 0.1 to 10 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber and / or the reaction control agent. It is a manufacturing method of the elastic roller of Claim 1 or 2 which contains 0.1-2 mass parts with respect to 100 mass parts of said vinyl group containing silicone raw rubber .
Y = 0.0086X + b (27 ≦ X ≦ 45)
However, in the said relational expression, b is 0.003-0.135, Y is a density (unit: g / cm < ³ >) of a foaming elastic layer, X is Asker C hardness of a foaming elastic layer.

  The foamed elastic layer in the elastic roller according to the present invention satisfies the above relationship between its Asker C hardness and density. That is, since the foamed elastic layer of this elastic roller has a predetermined density according to Asker C hardness, the hardness and density are high both in the longitudinal direction of the foamed elastic layer and in the thickness direction of the foamed elastic layer. Have uniformity. Here, since the foamed elastic layer usually has a constant volume, the uniformity of density can be translated into the uniformity of mass. Therefore, even if the elastic roller having the foamed elastic layer is incorporated in a recent high-definition and high-speed image forming apparatus and is repeatedly rotated and stopped at high speed for a long time, it is not decentered. Since the elastic roller itself and the contacted body are not deteriorated, it is possible to sufficiently contribute to the formation of a high-quality image over a long period of time because the elastic roller itself and the contacted body are not deteriorated.

Therefore, according to the present invention, it is possible to provide an elastic roller that forms a high-quality image and contributes to improving the durability of the image forming apparatus, and a manufacturing method thereof.

  As shown in FIG. 1, the elastic roller according to the present invention includes a shaft body 2 and an elastic layer 3 formed on the outer peripheral surface thereof. For example, the elastic roller is disposed in the image forming apparatus 30 shown in FIG. Is done.

  The shaft body 2 only needs to have good conductive properties, and is usually a so-called “core” made of iron, aluminum, stainless steel, brass, or the like. Further, the shaft body 2 may be a shaft body that is made conductive by plating an insulating core body such as a thermoplastic resin or a thermosetting resin. Furthermore, the shaft body 2 may be a thermoplastic resin or a thermosetting resin. The shaft body may be formed of a conductive resin in which carbon black or metal powder is blended as a conductivity imparting agent.

  The elastic layer 3 is formed on the outer peripheral surface of the shaft body 2 by a rubber composition described later. As shown in FIG. 4, the elastic layer 3 is a foamed elastic layer having cells 4 on the inside and / or outer surface thereof (in FIGS. 1 and 4, cells opened on the outer peripheral surface of the elastic layer 3). Is not shown.) When the elastic layer 3 is a foamed elastic layer, the hardness of the elastic layer 3 is reduced and the function of the elastic roller 1 is improved, so that a high-quality image can be formed. Here, the cell in the elastic layer 3 refers to a hollow region caused by foaming or decomposition of a foaming agent contained in the rubber composition, and a hollow region derived from a hollow filler contained in the rubber composition. . The plurality of cells 4 included in the elastic layer 3 are not in contact with or communicated with other cells (referred to as an independent cell state; see FIG. 4), in contact with or in communication with other cells. A state (referred to as a connected cell state) or a state in which the independent cell state and the connected cell state coexist. The elastic layer 3 has a cell size, a presence rate, and the like determined according to various rollers used in the image forming apparatus.

As shown in FIG. 2, the elastic layer 3 has a characteristic that the following relational expression is satisfied with respect to the density (Y, unit: g / cm ³ ) and the Asker C hardness (X). .

Y = 0.0086X + b (27 ≦ X ≦ 45)
(However, in the above relational expression, b is 0.003 to 0.135.)

  As shown in FIG. 2, the region satisfying the relational expression is a region where X is 27 or more and 45 or less, is a region represented by Y ≦ 0.0086X + 0.135, and Y ≧ 0.0086X + 0. This is an area indicated by 003. That is, the region satisfying the relational expression is surrounded by the regions on the straight lines represented by X = 27, X = 45, Y = 0.0006X + 0.135 and Y = 0.0006X + 0.003, and these straight lines. It is an area.

  Since Asker C hardness (X) is an index representing the hardness in the vicinity of the surface of the elastic layer, this Asker C hardness may not be able to adequately represent the characteristics of the entire elastic layer. That is, in the elastic layer, even if the value of Asker C hardness is constant, the portion near the surface of the elastic layer and the portion near the shaft body 2 in the depth direction of the elastic layer have the same hardness or the like. In some cases, the characteristics of the entire elastic layer cannot be sufficiently represented only by Asker C hardness. For example, as shown in FIG. 3, even if the Asker C hardness of the elastic layer 5 is adjusted to a specific value, the cell size, the existence rate per unit volume, etc. are not uniform in the depth direction. For example, the hardness and density in the depth direction of the elastic layer 5 are also non-uniform, and the characteristics of the entire elastic layer 5 cannot be adjusted. Therefore, the elastic layer 5 cannot exhibit a desired function or characteristic.

Under such circumstances, when the elastic layer 3 has a specific range of density according to Asker C hardness, in other words, the density is expressed as mass per unit volume (g / cm ^3). In addition, since the elastic layer 3 is usually adjusted to a constant volume, when the elastic layer 3 having a constant volume has a specific range of mass according to Asker C hardness, the elastic layer 3 3 in the longitudinal direction of the elastic layer 3 and also in the thickness direction of the elastic layer 3, it is found that the cell size, the abundance rate per unit volume, etc. are uniform. In order to achieve high image quality and improved durability when mounted on an image forming apparatus, the density of the elastic layer 3 in the elastic roller and the Asker C hardness representing the characteristics in the vicinity of the surface thereof are It was found that the relationship should be satisfied. That is, as shown in FIG. 4 as an example of the cross section of the elastic layer 3 in the elastic roller 1 according to the present invention, the elastic layer 3 satisfying the above relational expression has a cell size in the depth direction of the elastic layer 3. Since the abundance ratio per unit volume is substantially uniform, the hardness and density (that is, mass) in the depth direction of the elastic layer 3 are also substantially uniform, and although not shown, in the longitudinal direction of the elastic layer 3 The hardness and density (ie, mass) are also substantially uniform, and as a result, the hardness and density (ie, mass) are uniform throughout the elastic layer 3. Therefore, since the characteristic of the entire elastic layer 3 can be defined by the relational expression, if the relational expression is satisfied, the characteristic of the entire elastic layer 3 can be adjusted as desired. The function or characteristic of

  Therefore, when the relationship between the density (Y) of the elastic layer 3 and the Asker C hardness (X) is in the region, the hardness and density (that is, mass) in the longitudinal direction and depth direction of the elastic layer 3 are set to a desired value. As a result, a high-quality image can be formed over a long period of time.

  When the said area | region is demonstrated in detail, the Asker C hardness (X) in the said area | region is 27-45. When the Asker C hardness is 27 to 45, a desired contact state or pressure contact state with respect to the contacted body can be maintained, so that it can contribute mainly to forming a high-quality image. For example, when an elastic roller is used as a fixing roller in an image forming apparatus, a desired pressure contact state is maintained with respect to the pressure roller, and the nip width formed by the pressure roller and the fixing roller is increased. Therefore, the developer transferred to the recording medium can be fixed as desired, and as a result, it can contribute mainly to forming a high-quality image. The Asker C hardness can be a value obtained by measuring a plurality of locations of the elastic layer 3 in accordance with JIS K6253 and arithmetically averaging the measured values.

  The Asker C hardness of the elastic layer 3 can be determined by, for example, selecting the type of rubber and / or additive contained in the rubber composition forming the elastic layer 3 and / or changing the blending amount thereof. Also, it can be adjusted according to the molding conditions of the elastic layer 3 and the like.

  The density (Y) of the elastic layer 3 in the region is a region where Y = 0.0086X + 0.135 or less and Y = 0.0086X + 0.003 or more. When the density (Y) is within the above-described region, the elastic roller 1 is incorporated into a recent image forming apparatus with high definition and speed, and the elastic roller 1 is repeatedly rotated and stopped at high speed over a long period of time. In addition, since the elastic layer 3 of the elastic roller 1 can be prevented from being decentered and the elastic layer 3 and the contacted body can be prevented from being deteriorated, image formation over a long period of time, that is, in the image forming apparatus is mainly performed. This can contribute to improved durability. For example, when an elastic roller is mounted on an image forming apparatus as a fixing roller, a desired pressure contact state can be maintained for a long period of time with respect to the pressure roller. This can contribute to improving the durability of the image forming apparatus. The upper limit of the region is preferably Y = 0.0006X + 0.110, and more preferably Y = 0.0006X + 0.085 in that it can greatly contribute to image formation over a long period of time. The lower limit of Y is preferably 0.0086X + 0.028, and more preferably Y = 0.0006X + 0.053. In the present invention, the slope in the relational expression is adjusted to 0.0086 in that high uniformity of hardness and density can be achieved both in the longitudinal direction and in the thickness direction of the foamed elastic layer. However, even if the slope in the relational expression is adjusted to 0.0086 ± 0.0005, the uniformity of the hardness and density in the foamed elastic layer can be achieved.

  The density of the elastic layer 3 can be determined by measuring the volume and mass of the elastic layer 3 by a conventional method. The density of the elastic layer 3 is, for example, by selecting the type of rubber and / or various additives contained in the rubber composition forming the elastic layer 3, and / or by changing the blending amount thereof, etc. Moreover, it can adjust with the molding conditions of the elastic layer 3, for example, the heating conditions of the rubber composition which forms the elastic layer 3, etc.

  Thus, if the density (Y) and Asker C hardness (X) in the elastic layer 3 satisfy the relational expression, it can sufficiently contribute to forming a high-quality image over a long period of time.

  The thickness of the elastic layer 3 is not particularly limited, but is adjusted to a predetermined thickness according to various rollers disposed in the image forming apparatus, and is usually adjusted to a thickness of 2 to 20 mm. The thickness is preferably adjusted to 3 to 12 mm.

  The length of the elastic layer 3 is not particularly limited, but is adjusted to a predetermined thickness according to the recording medium printed by the image forming apparatus provided with the elastic roller 1. The length of the elastic layer 3 is usually adjusted to about 230 mm when an A4 size paper (JIS, 210 mm × 297 mm) is used as a recording medium, and the recording medium is A3 size (JIS, 297 mm × 2). In the case of using a 420 mm long paper, the length is adjusted to about 310 mm.

  As long as the density (Y) and Asker C hardness (X) satisfy the relational expression, the elastic layer 3 is not particularly limited in terms of properties such as strength and its material.

  The elastic roller 1 provided with the elastic layer 3 is a method in which a rubber composition is heat-molded by continuous heat molding by extrusion molding, pressing, mold molding by injection, or the like, and the elastic layer 3 is formed on the outer peripheral surface of the shaft body 2. Manufactured by.

The rubber composition forming the elastic layer 3 may be a composition containing rubber, a foaming agent or a hollow filler, and various additives as required, for example, forming a cell in an independent cell state. Preferred examples thereof include foamed silicone rubber-based compositions and foamed urethane rubber-based compositions. In particular, the foamed silicone rubber-based composition capable of forming a cell in an independent cell state is excellent in heat resistance, durability, resistance to residual strain, etc., and is suitable for a high-speed operation of an image forming apparatus. It is. As such a foamed silicone rubber composition, an addition reaction type foamed silicone rubber composition is particularly preferred. As a hollow filler, what is necessary is just a filler which can form a cell, for example after hardening | curing a rubber composition, For example, polyorganosiloxane type spherical powder is mentioned. The polyorganosiloxane spherical powder may be a spherical powder made of polyorganosiloxane, and examples thereof include silicone powder. More specifically, a silicone rubber powder having a structure in which linear dimethylpolysiloxane is crosslinked, and having a structure in which a siloxane bond is crosslinked in a three-dimensional network represented by (CH ₃ SiO _3/2 ) _n Examples thereof include a powder of silicone resin such as so-called polymethylsilsesquioxane, and a powder of coated silicone rubber in which the surface of the silicone rubber is coated with silicone resin or the like.

  The addition reaction type foamed silicone rubber composition contains a vinyl group-containing silicone raw rubber, a silica-based filler, a foaming agent, an addition reaction crosslinking agent, an addition reaction catalyst, and a reaction control agent. An organic peroxide crosslinking agent, a heat resistance improver, and various additives may be contained.

  Examples of the vinyl group-containing silicone raw rubber include millable silicone rubber and heat-crosslinked silicone rubber (HTV: High Temperature Vulcanizing). These vinyl group-containing silicone raw rubbers have the property that a foaming agent and an addition reaction cross-linking agent can be easily kneaded with a roll mill or the like in a later step, and are used alone or in combination of two or more. Can be used.

Examples of the silica-based filler include a fumed silica or a precipitated silica having a reinforcing property, and a surface having a high reinforcing effect that is surface-treated with a silane coupling agent represented by a general formula RSi (OR ′) _3. A treated silica-based filler is preferred. Here, R in the general formula is a glycidyl group, vinyl group, aminopropyl group, methacryloxy group, N-phenylaminopropyl group, mercapto group or the like, and R ′ in the general formula is a methyl group or an ethyl group. . The silane coupling agent represented by the general formula can be easily obtained, for example, as trade names “KBM1003” and “KBE402” manufactured by Shin-Etsu Chemical Co., Ltd. Such a silica-based filler surface-treated with a silane coupling agent can be obtained by treating the surface of the silica-based filler according to a conventional method. The compounding amount of the silica-based filler is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. A silica type filler can be used individually by 1 type or in mixture of 2 or more types.

  The foaming agent may be any foaming agent conventionally used for foamed rubber. Examples of the inorganic foaming agent include sodium bicarbonate and ammonium carbonate. Examples of the organic foaming agent include diazoamino derivatives, azonitrile derivatives, azo And organic azo compounds such as dicarboxylic acid derivatives. Usually, an inorganic foaming agent is used when forming continuous cells in rubber, and an organic foaming agent is used when forming independent cells. In the elastic roller 1, the foaming agent is preferably an organic foaming agent in that it can form a cell in an independent cell state. Specifically, for example, azodicarboxylic acid amide, azobis-isobutyrate is used. An azo compound such as ronitrile is preferably used. In particular, dimethyl-1,1'-azobis (1-cyclohexanecarboxylate) can be preferably used. The blending amount of the foaming agent varies depending on the type of the foaming agent, but it is preferable to adjust so that the Asker C hardness of the elastic layer 3 is 27 to 45. Specifically, for example, it may be 0.1 to 10 parts by mass, particularly 0.5 to 10 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. If the blending amount of the foaming agent is less than 0.1 parts by mass, sufficient cells may not be formed in the formed elastic layer 3, while if it exceeds 10 parts by mass, the foamed silicone rubber In this case, the mechanical strength of the elastic layer 3 may be reduced. When dimethyl-1,1′-azo-bis (1-cyclohexanecarboxylate) is selected as the foaming agent, the blending amount is 0.5 to 5 with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. The mass part is particularly good. A foaming agent can be used individually by 1 type or in mixture of 2 or more types.

  As the addition reaction crosslinking agent, for example, a known organohydrogenpolysiloxane can be used as an addition reaction type crosslinking agent having two or more SiH groups (SiH bonds) in one molecule. The organohydrogenpolysiloxane may be linear, cyclic or branched. The compounding amount of the organohydrogenpolysiloxane is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. An addition reaction crosslinking agent can be used individually by 1 type or in mixture of 2 or more types.

  The addition reaction catalyst includes, for example, a simple substance of Group 9 or 10 of the periodic table and a compound thereof, and more specifically, particulate platinum adsorbed on a carrier such as silica, alumina, or silica gel. Metals, platinum chloride, chloroplatinic acid, chloroplatinic acid hexahydrate and olefin or divinyldimethylpolysiloxane complexes, platinum-based catalysts such as chloroplatinic acid hexahydrate alcohol solutions, palladium catalysts, rhodium catalysts, etc. Can be mentioned. The addition amount of these addition reaction catalysts is sufficient as the catalyst amount, and is usually 1 in terms of the total amount of addition reaction type foamed silicone rubber composition in terms of the metal amount of Group 9 or Group 10 of the Periodic Table. It is good that it is -1,000 ppm, and it is especially good that it is 10-500 ppm. If the amount of addition reaction catalyst is less than 1 ppm in terms of the metal content of Group 9 or Group 10 of the Periodic Table, the crosslinking reaction of vinyl group-containing silicone raw rubber does not proceed sufficiently, and vinyl group-containing silicone Curing of the raw rubber may be insufficient. On the other hand, if it exceeds 1,000 ppm, the ability to accelerate the crosslinking reaction of the vinyl group-containing silicone raw rubber is not improved, and the economic efficiency may be lowered. An addition reaction catalyst can be used individually by 1 type or in mixture of 2 or more types.

  As the reaction control agent, known reaction control agents can be used without limitation, and examples thereof include methylvinylcyclotetrasiloxane, acetylene alcohols, siloxane-modified acetylene alcohol, and hydroperoxide. The compounding amount of the reaction control agent is preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. The reaction control agents can be used alone or in combination of two or more.

  The organic peroxide cross-linking agent can be used alone to cross-link vinyl group-containing silicone raw rubber, but if used in combination as an auxiliary cross-linking agent for an addition reaction cross-linking agent, the physical properties of the silicone rubber, such as strength and strain, can be improved. improves. Examples of the organic peroxide crosslinking agent include benzoyl peroxide, bis-2,4-dichlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, and 2,5-dimethyl-2,5-bis. (T-butylperoxy) hexane and the like. The compounding amount of the organic peroxide crosslinking agent is preferably 0.3 to 10 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. An organic peroxide crosslinking agent can be used individually by 1 type or in mixture of 2 or more types.

  The heat resistance improver may be any compound that improves the heat resistance of the elastic layer 3, and examples thereof include carbon black, iron oxide (also referred to as bengara), cerium oxide, and cerium hydroxide. These can be used individually by 1 type or in mixture of 2 or more types.

The carbon black can be generally classified into furnace black, channel black, acetylene black, thermal black, etc. depending on the production method. However, if the content of sulfur, amine, etc. is large, the addition reaction type foamed silicone rubber composition Since the addition reaction may be inhibited, carbon black having a low content of sulfur, amine, etc., for example, acetylene black is preferably used. Preferred examples of the iron oxide include black bengara (Fe ₃ O ₄ ) and red bengara (Fe ₂ O ₃ ). The cerium oxide and the cerium hydroxide may be used alone, but it is preferable that the cerium oxide and the cerium hydroxide are used together with the carbon black and / or the iron oxide because the change in hardness of the elastic layer 3 can be suppressed. .

  The total amount of the heat resistance improver is preferably 0.1 to 35 parts by mass, and particularly preferably 1 to 10 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. If the total blending amount of the heat resistance improver is within the above range, the blending amounts of carbon black, iron oxide, cerium oxide and cerium hydroxide are not particularly limited. For example, the compounding amount of the carbon black is preferably 0 to 15 parts by mass, more preferably 0.2 to 15 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. The mass part is particularly good. The blending amount of Bengala is preferably 0 to 30 parts by mass, more preferably 0.2 to 30 parts by mass, and 2 to 20 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. There is especially good. The blending amounts of cerium oxide and cerium hydroxide are preferably 0.1 to 5 parts by weight, particularly 0.2 to 2 parts by weight, based on 100 parts by weight of the vinyl group-containing silicone raw rubber. Good.

  The various additives include, for example, fillers such as calcium carbonate, colorants, flame retardant improvers, thermal conductivity improvers, release agents, alkoxy silanes, diphenyl silane diols, carbon functional silanes, Examples thereof include dispersants such as both-end silanol-blocked low-molecular siloxanes, and non-reinforcing silica such as pulverized quartz and diatomaceous earth that can adjust the hardness of the resulting rubber. These various additives are blended in a desired blending amount.

  As the silicone rubber composition containing the vinyl group-containing silicone raw rubber, the silica filler, and the various additives, for example, trade names “KE series” and “KEG series” manufactured by Shin-Etsu Chemical Co., Ltd. can be easily used. It can be obtained.

  The specific gravity of the rubber composition is not particularly limited. However, since the specific gravity of the rubber composition also affects the density of the elastic layer 3 to some extent, depending on the various rollers disposed in the image forming apparatus, a specific specific gravity is obtained. Adjusted. The specific gravity of the rubber composition is usually preferably 1.00 to 2.00, more preferably 1.05 to 1.50.

  The rubber composition is, for example, several minutes to several hours, preferably 5 until it is uniformly mixed using a rubber kneader such as a two-roll, three-roll, roll mill, Banbury mixer, dough mixer (kneader) or the like. It is obtained by kneading at room temperature or under heating for 1 minute to 1 hour.

  A method for manufacturing the elastic roller 1 will be described below. In order to manufacture the elastic roller 1, first, an adhesive or primer is applied to the outer peripheral surface of the shaft body 2 in advance by a spray method, a dipping method, or the like, if necessary. It is preferable to form a primer layer. The primer is not particularly limited, and examples thereof include a silane coupling primer. The adhesive is not particularly limited, and examples thereof include alkyd resins, phenol-modified / silicone-modified alkyd resin modified products, oil-free alkyd resins, acrylic resins, silicone resins, epoxy resins, fluororesins, phenol resins, polyamides. Resins, urethane resins and mixtures thereof may be mentioned. Among these, an adhesive having an amino group and / or a hydroxyl group is preferable. Moreover, an isocyanate compound, a melamine compound, an epoxy compound, a peroxide, a phenol compound, a hydrogensiloxane compound, etc. are used as a crosslinking agent for curing these resins.

  Next, a rubber composition for forming the elastic layer 3 is disposed on the outer peripheral surface of the shaft body 2 on which the adhesive layer or primer layer is formed. As a method of disposing the rubber composition on the outer peripheral surface of the shaft body 2, for example, the shaft body 2 and the rubber composition are integrally extracted by an extruder or the like, and the rubber composition is disposed on the outer peripheral surface of the shaft body 2. And a method of injecting a rubber composition into a mold for housing the shaft body 2 and disposing the rubber composition on the outer peripheral surface of the shaft body 2. Among these, the method of dispensing the shaft body 2 and the rubber composition integrally with an extruder or the like is preferable in terms of easy work and continuous work.

  After arranging the rubber composition on the outer peripheral surface of the shaft body 2 in this way, the rubber composition is heated together with the shaft body 2 while maintaining this state. The heating of the rubber composition may be performed under conditions sufficient for the rubber contained in the rubber composition, for example, the vinyl group-containing silicone raw rubber to crosslink and the foaming agent to decompose or foam. For example, the rubber composition is usually heated to about 170 to 500 ° C., particularly 200 to 400 ° C. by a heating furnace such as an infrared heating furnace or a hot air oven, a heating machine such as a dryer, and the like. In particular, it is heated for 5 to 30 minutes.

  One method of forming the elastic layer 3 that satisfies the above relational expression is a method of adjusting the rate of temperature rise when heating the rubber composition disposed on the outer peripheral surface of the shaft body 2. For example, for example, the temperature rising time when the rubber composition disposed on the outer peripheral surface of the shaft body 2 is heated from room temperature (for example, 20 to 30 ° C.) to 90 ° C. is adjusted within 80 seconds. Preferably, the heating condition is such that the heating time when heating from 90 ° C. to 200 ° C. is adjusted within 240 seconds, and then heated to a temperature sufficient for the foaming agent to decompose or foam for a predetermined time. If the temperature rising time when heating to 90 ° C. exceeds 80 seconds, foaming of the foaming agent may be insufficient, and the elastic layer 3 that satisfies the relational expression may not be formed. Further, if the temperature rising time when heating from 90 ° C. to 200 ° C. exceeds 240 seconds, the balance between foaming and cross-linking of the foaming agent is lost, particularly the degree of foaming in the vicinity of the shaft body 2 is insufficient. The elastic layer 3 that satisfies the equation may not be formed. Under these heating conditions, the heating time when heating to 90 ° C. may be very short, but about 5 seconds is realistic, and the heating time when heating from 90 ° C. to 200 ° C. is Although it may be very short, about 60 seconds is realistic. Under these heating conditions, the heating time when heating to 90 ° C. is preferably within 60 seconds, and more preferably within 40 seconds. Further, the heating time when heating to 200 ° C. is preferably within 200 seconds, and more preferably within 180 seconds. Such adjustment of the heating time can be performed by a known means.

  If desired, the rubber composition may be further subjected to secondary heating. The secondary heating is a step of more reliably crosslinking the rubber composition crosslinked under the above conditions, and the effect of stabilizing the physical properties of the elastic layer 3 is obtained by the secondary heating. In the secondary heating, for example, the rubber composition cross-linked under the above-described conditions is further in an extruded state, for example, 180 to 250 ° C, preferably 190 to 230 ° C, for 1 to 24 hours. Heating again for 3 to 10 hours or using a mold, for example, at 130 to 200 ° C., preferably 150 to 180 ° C. for 5 minutes to 24 hours, preferably 10 minutes to 10 hours or less Is done.

  The elastic layer 3 thus molded is subjected to a grinding process, a polishing process and / or a cutting process, etc., which are adjusted to a desired size and shape as a finishing process, if desired. The grinding process, the polishing process, and / or the cutting process can be performed according to a conventional method using a conventionally used grinder, cylindrical grinder, file, or the like. In addition, the elastic layer 3 may be washed as desired in order to remove grinding residue, polishing residue, foreign matter, and the like after the grinding step, the polishing step and / or the cutting step. Examples of the cleaning include wet cleaning using water and / or wiping cleaning using waste or the like, blowing cleaning, and the like.

  In this way, the elastic roller 1 is manufactured, and the elastic roller 1 includes the elastic layer 3 that satisfies the above relational expression. Therefore, various rollers of the image forming apparatus, such as a transfer roller, a developing roller, and a charging roller. It is preferably used for a fixing roller, a pressure roller, a paper feed roller and the like, particularly for a fixing roller.

  In particular, when the elastic roller 1 is disposed in the image forming apparatus, the elastic roller 1 can act uniformly on the contacted body without being decentered. It is possible to sufficiently contribute to forming a high-quality image over a long period of time without deterioration of the contacted body.

  The elastic roller 1 includes an elastic layer 3 on the outer peripheral surface of the shaft body 2. In the present invention, a coat layer, a surface layer, and / or a protective layer are formed on the outer peripheral surface of the elastic layer 3 as desired. May be. The coat layer, the surface layer and the protective layer are usually formed on the outer peripheral surface of the elastic layer 3 to a thickness of 1 to 100 μm according to a conventional method. The material for forming the coat layer, the surface layer, and the protective layer is not particularly limited, but the elastic roller 1 is preferably a material that is not easily permanently deformed because it is in contact with or pressed against the contacted body. For example, alkyd resins, phenol-modified / silicone-modified alkyd resin modified products, oil-free alkyd resins, acrylic resins, silicone resins, epoxy resins, fluororesins, phenol resins, polyamide resins, urethane resins, polyamideimide resins, and the like And the like.

  The elastic roller 1 may include a heating body, for example, an electric heater, a heating coil, or the like, in the shaft body 2, in the elastic layer 3 and / or between the shaft body 2 and the elastic layer 3, depending on the application. Good. For example, when the elastic roller 1 is used as a fixing roller of a heat roller fixing device, a heating body is provided in the shaft body 2.

  In the present invention, the relational expression can also be used as one of the indexes for evaluating the elastic roller 1 by measuring the Asker C hardness and density of the elastic layer 3. An evaluation method of the elastic roller 1 using the relational expression can also be provided. That is, in this evaluation method, the Asker C hardness and density of the elastic roller 1 are measured by the measurement method, and the elastic roller 1 has a desired characteristic or function depending on whether or not these measured values satisfy the relational expression. It can be evaluated whether it has. According to this method, since the elastic layer 3 can be evaluated without using a destructive method such as cutting, the measured elastic roller 1 can be used as a product, and only the desired elastic roller 1 is individually provided. As a result, the elastic roller 1 can be reliably evaluated.

  Next, a fixing device provided with the elastic roller 1 according to the present invention (hereinafter sometimes referred to as a fixing device according to the present invention) and an image forming device (hereinafter referred to as an image forming device according to the present invention). .) Will be described with reference to FIG.

  As shown in FIG. 5, the image forming apparatus 30 according to the present invention includes a rotatable image carrier 31 on which an electrostatic latent image is formed, for example, a photosensitive member, and abuts or presses against the image carrier 31 or A charging unit 32 that charges the image carrier 31, for example, a charging roller, and an exposure unit 33 that is provided above the image carrier 31 and forms an electrostatic latent image on the image carrier 31. A developing means 40 which is provided in contact with or pressure contact with the image carrier 31 or at a predetermined interval, supplies the developer 42 with a constant layer thickness to the image carrier 31 and develops the electrostatic latent image; The transfer means 34, for example, a transfer roller, which is provided so as to be pressed against the image carrier 31 and transfers the developed electrostatic latent image from the image carrier 31 onto the recording medium 36, for example, recording paper, and the conveyance of the recording body 36. Provided downstream in the direction and transferred to the recording body 36. Fixing means 35 for fixing the image material 42 (electrostatic latent image), for example, a fixing device, developer 42 not transferred to the recording medium 36 and remaining on the image carrier 31 and / or dust adhering to the image carrier 31 and the like. And a cleaning means 37 to be removed. The image forming apparatus 30 includes a neutralizing unit (not shown) for removing an electrostatic latent image remaining on the surface of the image carrier 31 between the cleaning unit 37 and the charging unit 32 or the transfer unit 34 and the cleaning unit. 37 may be provided.

  The developing means 40 in the image forming apparatus 30 is basically formed in the same manner as the developing means provided in the conventional image forming apparatus, and is arranged in the same manner. For example, as illustrated in FIG. 5, the developing unit 40 has an opening at a position facing the image carrier 31, and includes a developer storage unit 41 that stores the developer 42, and an opening of the developer storage unit 41. A rotatable developer carrier 44 provided in contact with or in pressure contact with the image carrier 31 or at a predetermined interval, and supplying the developer 42 with a constant layer thickness to the image carrier 31; Provided in contact with the developer carrier 44, and provided with a rotatable developer supply means 43 for supplying the developer 42 to the developer carrier 44, and above the developer carrier 44, and provided with the developer carrier 44. And a developer regulating member 45 that regulates the layer thickness of the developer 42 and charges the developer 42 by frictional charging.

  The developer accommodated in the developer accommodating portion 41 is a one-component developer that can be charged by friction and can be fixed to the recording medium 36, even if it is a dry developer, a wet developer. It may be a non-magnetic developer or a magnetic developer.

  The fixing unit 35 is only required to fix the developer 42 (electrostatic latent image) transferred to the recording body 36. For example, a heat roller fixing device having a heat generating fixing roller, an oven fixing device, etc. A heat fixing device, a pressure fixing device including a fixing roller capable of pressing, and the like can be used. These fixing devices may be fixing devices having endless belts. In FIG. 5, fixing means 35 having an endless belt is the fixing device according to the present invention. As shown in FIG. 5, the fixing device 35 includes a fixing roller 53 and a support for an endless belt disposed in the vicinity of the fixing roller 53 in a housing 50 having an opening 52 through which the recording medium 36 passes. A roller 54, an endless belt 55 wound around the fixing roller 53 and the endless belt support roller 54, and a pressure roller 56 disposed opposite to the fixing roller 53. The pressure heat fixing device is configured to be rotatably supported so that the pressure roller 56 is in contact with or in pressure contact with each other. The endless belt support roller 54 may be a roller that is normally used in an image forming apparatus. For example, an elastic roller or the like is used. For example, the endless belt 55 may be an endless belt formed of a resin such as polyamide or polyamideimide, and the thickness of the endless belt 55 may be appropriately adjusted to match the fixing unit 35. Each of the fixing roller 53, the endless belt support roller 54, and the pressure roller 56 includes a heating body (not shown), and the pressure roller 56 causes the endless belt 55 to be moved by a biasing means (not shown) such as a spring. Via the fixing roller 53. By passing the recording medium 36 between the endless belt 55 and the pressure roller 56, the recording medium 36 is heated simultaneously with the pressurization, and the developer 42 (electrostatic latent image) transferred to the recording medium 36 is fixed. be able to.

  The image forming apparatus 30 according to the present invention includes a charging roller of the charging unit 32, a developing roller of the developing unit 40, a transfer roller of the transfer unit 34, a fixing roller of the fixing unit 35, a pressure roller or an endless belt support roller, and a cleaning unit. Various rollers such as a cleaning roller and a paper feeding / conveying roller are provided, and the elastic roller 1 according to the present invention is used as at least one of these various rollers. Preferably, the elastic roller 1 according to the present invention is used as at least one of a charging roller, a developing roller, a transfer roller, a fixing roller, and a pressure roller.

  The image forming apparatus 30 according to the present invention operates as follows. First, in the image forming apparatus 30, the developer 42 and / or dust on the surface is removed by the cleaning unit 37 while the image carrier 31 rotates clockwise as indicated by the arrow in FIG. 5. Thereafter, it is uniformly charged by the charging means 32. Next, the image is exposed by the exposure means 33, and an electrostatic latent image is formed on the surface of the image carrier 31.

  On the other hand, in the developing means 40, the developer 42 is supplied to the developer carrier 44 by the developer supply means 43, and the developer carrier 44 rotates in the direction of the arrow shown in FIG. The developer 42 adhered to the surface of the toner passes between the developer carrier 44 and the developer regulating member 45 in contact with the developer carrier 44. At this time, the developer 42 is regulated to a desired layer thickness, and the developer 42 can be charged as desired. That is, as the developer 42 passes between the developer carrier 44 and the developer regulating member 45, the layer thickness of the developer 42 on the surface of the developer carrier 44 is regulated, and the developer The developer 42 on the developer carrier 44 is charged as desired by frictional charging between the regulating member 45 and the developer carrier 44 and / or the developer 42.

  Next, the developer 42 having a desired layer thickness and charge amount is supplied from the developing means 40 to the image carrier 31 in this way, and the electrostatic latent image formed on the image carrier 31 is developed. The electrostatic latent image is visualized as a developer image. In this way, the developing unit 40 can supply the developer 42 having a desired layer thickness and charge amount to the image carrier 31 to develop the electrostatic latent image. Next, the developer image developed on the image carrier 31 is transferred onto the recording medium 36 conveyed between the image carrier 31 and the transfer unit 34 by the conveyance unit. 34 is transferred. Next, the recording body 36 onto which the developer image has been transferred is transported to the fixing means 35 by the transporting means, heated and / or pressurized by the fixing means 35, and the transferred developer image is recorded as a permanent image on the recording body 36. To be established. In this way, an image can be formed on the recording body 36.

  The image forming apparatus 30 according to the present invention includes at least one of various rollers such as a charging roller, a developing roller, a transfer roller, a fixing roller, a pressure roller, an endless belt support roller, a cleaning roller, and a paper feed / conveying roller. The elastic roller 1 according to the present invention is used, and the roller using the elastic roller 1 according to the present invention has hardness and density (that is, mass) both in the longitudinal direction and in the thickness direction of the foamed elastic layer. Since the elastic roller itself and the contacted body are not deteriorated, the high quality image can be obtained over a long period of time. Can contribute enough to form. For example, when the elastic roller 1 according to the present invention is used as the fixing roller 53, it is incorporated into a recent image forming apparatus with high definition and speed and is repeatedly rotated and stopped at high speed for a long period of time. The endless belt 55 and the pressure roller 56 which are the contacted bodies can be uniformly acted without being eccentric, so that the elastic roller 1 itself, the endless belt 55 and the pressure roller 56 are The developer transferred to the recording body 36 can be fixed as desired without deterioration, and as a result, it can sufficiently contribute to forming a high-quality image over a long period of time.

  The image forming apparatus 30 is an electrophotographic image forming apparatus. However, in the present invention, the image forming apparatus is not limited to the electrophotographic system, and may be, for example, an electrostatic image forming apparatus. Good. Further, the image forming apparatus 30 is a monochrome image forming apparatus in which the developing unit 40 contains only a single color developer 42. However, in this invention, the image forming apparatus is not limited to a monochrome image forming apparatus. It may be an image forming apparatus. Examples of the color image forming apparatus include a four-cycle color image forming apparatus that sequentially repeats primary transfer of a developer image carried on an image carrier to an intermediate transfer body, and a plurality of image carriers provided with developing means for each color. Examples thereof include a tandem type color image forming apparatus in which a body is arranged in series on an intermediate transfer body or a transfer conveyance belt. The image forming apparatus 30 is an image forming apparatus such as a copying machine, a facsimile machine, or a printer.

  In the image forming apparatus 30, a one-component developer is advantageously used as the developer 42, but a two-component developer including a toner and a carrier such as iron or nickel can also be used. .

Example 1
First, an electroless nickel-plated shaft (diameter 12 mm x length 350 mm, SUM22) was washed with toluene, and primer “No. 101A / B” (manufactured by Shin-Etsu Chemical Co., Ltd .: trade name) was applied. did. The primer-treated shaft was fired at 180 ° C. for 30 minutes using a gear oven, and then cooled at room temperature for 30 minutes or more to form a primer layer.

  Subsequently, 100 parts by mass of a silicone rubber composition “KE-904FU” (manufactured by Shin-Etsu Chemical Co., Ltd .: trade name) containing a vinyl group-containing silicone raw rubber and a silica-based filler, and an addition reaction crosslinking agent “C-153A” ( Shin-Etsu Chemical Co., Ltd .: trade name) 2.0 parts by mass, foaming agent azobis-isobutyronitrile “KEP-13” (Shin-Etsu Chemical Co., Ltd .: trade name) 2.5 parts by mass, and addition reaction An appropriate amount of platinum catalyst as a catalyst, 0.5 parts by mass of a reaction control agent “R-153A” (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), and an organic peroxide cross-linking agent “C-3” (Shin-Etsu Chemical Co., Ltd.) Company: product name) Appropriate amount of heat resistance improver "KEP-12" (manufactured by Shin-Etsu Chemical Co., Ltd .: product name) 1.0 part by mass sufficiently with two rolls, addition reaction type A foamed silicone rubber composition A was prepared.

  Next, the shaft body on which the primer layer is formed and the addition reaction type foamed silicone rubber composition are integrally extracted with an extruder, and then the addition reaction type foamed silicone rubber is used using an infrared heating furnace (IR furnace). The composition was heated to 90 ° C. in 30 seconds, subsequently heated from 90 ° C. to 200 ° C. in 180 seconds, further heated to 230 ° C. and held at that temperature for 12 minutes (hereinafter referred to as “heating condition A”) The addition reaction type foamed silicone rubber composition A was foamed and crosslinked. Then, the addition reaction type | mold foaming silicone rubber composition after foaming bridge | crosslinking was further heated for 7 hours at 200 degreeC using the gear oven, and was left to stand at normal temperature for 1 hour. Subsequently, the outer diameter of the formed elastic layer was adjusted to 29 mm with a cylindrical grinder. Thus, the elastic roller A provided with the foaming elastic layer was produced.

(Example 2)
Example 1 except that the addition reaction type foamed silicone rubber composition A used in the addition reaction type foamed silicone rubber composition A was changed to 0.8 parts by mass of the reaction control agent “R-153A”. In the same manner, an elastic roller B was produced.
(Example 3)
The addition reaction type foamed silicone rubber composition A is heated to 90 ° C. in 80 seconds, subsequently heated from 90 ° C. to 200 ° C. in 215 seconds, further heated to 230 ° C. and held at the same temperature for 11 minutes and 30 seconds ( Hereinafter, the elastic roller C was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition A was foamed and crosslinked.

Example 4
In addition reaction type foamed silicone rubber composition A, except that addition reaction type foamed silicone rubber composition C in which the blending amount of the foaming agent azobis-isobutyronitrile “KEP-13” was changed to 3.0 parts by mass was used. Produced the elastic roller D in the same manner as in Example 1.
(Example 5)
In the addition reaction type foamed silicone rubber composition A, the blending amount of the foaming agent azobis-isobutyronitrile “KEP-13” was changed to 3.0 parts by mass, and the reaction control agent “R-153A” An elastic roller E was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition D in which the blending amount was changed to 0.8 parts by mass was used.
(Example 6)
An elastic roller F was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition C was foamed and crosslinked under the heating condition B.
(Example 7)
In addition reaction type foamed silicone rubber composition A, except that addition reaction type foamed silicone rubber composition E in which the blending amount of the foaming agent azobis-isobutyronitrile “KEP-13” was changed to 1.5 parts by mass was used. Produced the elastic roller G in the same manner as in Example 1.
(Example 8)
In addition reaction type foamed silicone rubber composition A, the blending amount of the foaming agent azobis-isobutyronitrile “KEP-13” was changed to 1.5 parts by mass, and the reaction control agent “R-153A” An elastic roller H was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition F in which the blending amount was changed to 0.8 parts by mass was used.
Example 9
An elastic roller I was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition E was foam-crosslinked under the heating condition B.

(Comparative Example 1)
The addition reaction type foamed silicone rubber composition A was heated to 90 ° C. in 105 seconds, subsequently heated from 90 ° C. to 200 ° C. in 285 seconds, further heated to 230 ° C. and held at that temperature for 9 minutes (hereinafter, The elastic roller J was prepared in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition A was foamed and crosslinked.
(Comparative Example 2)
In addition reaction type foamed silicone rubber composition A, the blending amount of the foaming agent azobis-isobutyronitrile “KEP-13” was changed to 2.5 parts by mass, and the reaction control agent “R-153A” An elastic roller K was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition G in which the blending amount was changed to 1.0 part by mass was used.
(Comparative Example 3)
An elastic roller L was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition C was foam-crosslinked under the heating condition C.
(Comparative Example 4)
In the addition reaction type foamed silicone rubber composition A, the blending amount of the foaming agent azobis-isobutyronitrile “KEP-13” was changed to 3.0 parts by mass, and the reaction control agent “R-153A” An elastic roller M was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition H in which the blending amount was changed to 1.0 part by mass was used.
(Comparative Example 5)
An elastic roller N was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition E was foam-crosslinked under the heating condition C.
(Comparative Example 6)
In addition reaction type foamed silicone rubber composition A, the blending amount of the foaming agent azobis-isobutyronitrile “KEP-13” was changed to 1.5 parts by mass, and the reaction control agent “R-153A” An elastic roller O was produced in the same manner as in Example 1 except that the addition reaction type foamed silicone rubber composition I in which the blending amount was changed to 1.0 part by mass was used.

  The Asker C hardness at 6 locations (2 locations near the center and 4 locations near both ends) on the surface of each elastic layer in the elastic rollers A to O thus produced was measured by the above method, and the arithmetic average value of these values was calculated. It was set as the average hardness (Asker C) of each elastic layer. The results are shown in Table 1.

On the other hand, as the mass of the elastic layer, the masses of the elastic rollers A to O were measured, and the difference from the mass (238.0 g) of the shaft body on which the primer layer was formed was determined. Further, the outer diameter of the elastic layer was measured with a laser length measuring machine at five points (circumference) obtained by equally dividing the entire length of the elastic layer into four equal parts, and the outer diameter (average) for any elastic roller. Was 2.90 cm, and the volume of the elastic layer was determined from the measured outer diameter, length of the elastic layer, etc., and was 151.8 cm ³ in any elastic roller. From the measured mass and volume of the elastic layer, the density (g / cm ³ ) of each elastic layer was calculated. These results are shown in Table 1.

  In Examples 1 to 9, the relationship between Asker C hardness (X) and density (Y) in the elastic layers of the elastic rollers A to I is as follows: Y ≦ 0.0086X + 0.135, and Y ≧ 0. It was included in the region of 0086X + 0.003. On the other hand, in Comparative Examples 1 to 6, the relationship between the Asker C hardness (X) and the density (Y) in the elastic layer of the elastic rollers J to O is an area where Y> 0.0086X + 0.135, or Y It existed in the region of <0.0086X + 0.003.

  The durability of the elastic rollers A to O produced in Examples 1 to 9 and Comparative Examples 1 to 6 was tested using the durability test apparatus 70 shown in FIG. 6 by the following method. This durability test apparatus 70 is fixed to the lower surface inside the casing, and includes a heating roller 71 provided with an internal heater 72, and external heaters 73 provided on both sides of the heating roller 71 along the axial direction. A test roller mounting portion 74 provided on the upper surface inside the housing so as to be movable up and down so as to face the heating roller 71, and a pressing force adjusting means 75 capable of moving the test roller mounting portion 74 up and down, for example, pressure adjustment A micrometer. As the heating roller 71, a metal (stainless steel, SUS304) roller having a diameter of 20 mm was used.

  The elastic rollers A to O produced in Examples 1 to 9 and Comparative Examples 1 to 6 are respectively mounted on the bearings of the test roller mounting portion 74, and the pressing force adjusting means 75 is operated as shown in FIG. The attached elastic roller 76 is pressed against the heating roller 71, and the elastic roller 76 is fixed so that the elastic layer of the elastic roller 76 is recessed 3 mm inside at the press-contact portion between the heating roller 71 and the elastic roller 76 (that is, The distance d between the central axis of the elastic roller 76 and the central axis of the heating roller 71 was adjusted so as to be 3 mm shorter than the sum of the outer diameter of the elastic roller 76 and the outer diameter of the heating roller 71.

  Next, the external heater 73 and the internal heater 72 were started, and the surface temperature of the heating roller 71 was adjusted to 180 ° C. Thereafter, the driving means (not shown) provided in the test roller mounting part 74 is continuously operated for 8 hours at a rotational speed of 130 rpm, and after the elastic layer 76 is released from the recessed state of the elastic layer, the elastic roller 76 is kept at room temperature for 24 hours. Left for hours.

  The evaluation is “○” when there is no deformation deformation in the axial direction of the elastic layer after the test, and uneven wear of the elastic layer is not confirmed, or slight deformation unevenness in the axial direction of the elastic layer or slight deformation of the elastic layer. The case where uneven wear was confirmed was indicated by “Δ”, and the case where deformation unevenness of the elastic layer, uneven wear, etc. were confirmed was indicated by “x”. The results are shown in Table 1.

  In addition, the elastic roller after the endurance test is completed is taken out of the image forming apparatus, and the elastic layer of the elastic roller is cut along a plane perpendicular to the longitudinal direction. Uniformity was evaluated visually. In order from the higher cell uniformity, the evaluation is made in a five-step evaluation of 5, 4, 3, 2 and 1, and the results are shown in Table 1.

FIG. 1 is a perspective view showing an example of an elastic roller according to the present invention. FIG. 2 is a graph showing the relationship between Asker C hardness and density in the elastic layer according to the present invention. FIG. 3 is a perspective view showing a cross section of a conventional elastic roller. FIG. 4 is a perspective view showing a cross section of the elastic roller according to the present invention. FIG. 5 is a schematic view of the essential portions showing an example of the image forming apparatus according to the present invention. FIG. 6 is a schematic diagram showing a durability test apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic roller 2 Shaft body 3, 5 Elastic layer 4 Cell 30 Image forming apparatus 31 Image carrier 32 Charging means 33 Exposure means 34 Transfer means 35 Fixing means 36 Transfer object 37 Cleaning means 40 Developing means 41 Developer storage part 42 Development Agent 43 Developer supply means 44 Developer carrier 45 Developer regulating member 50 Housing 52 Opening 53 Fixing roller 54 Endless belt support roller 55 Endless belt 56 Pressure roller 70 Durability test device 71 Heating roller 72 Internal heater 73 External heater 74 Test roller mounting part 75 Pressure adjusting means

Claims (3)

A method for producing an elastic roller having a foamed elastic layer in which Asker C hardness and density satisfy the following relational expression , comprising vinyl group-containing silicone raw rubber, silica-based filler and foaming agent disposed on the outer peripheral surface of the shaft body The addition reaction type foamed silicone rubber composition containing an addition reaction crosslinking agent, an addition reaction catalyst, and a reaction control agent is heated to 90 ° C. with a temperature rising time within 80 seconds, and then with a temperature rising time within 240 seconds. A method for producing an elastic roller that is heated to ° C.
Y = 0.0086X + b (27 ≦ X ≦ 45)
However, in the said relational expression, b is 0.003-0.135, Y is a density (unit: g / cm < ³ >) of a foaming elastic layer, X is Asker C hardness of a foaming elastic layer.   The method for producing an elastic roller according to claim 1, wherein the rubber composition is further heated to a temperature sufficient for the foaming agent to decompose or foam. In the addition reaction type foamed silicone rubber composition, the foaming agent is 0.1 to 10 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber, and / or the reaction control agent is the vinyl group. The manufacturing method of the elastic roller of Claim 1 or 2 contained in the ratio of 0.1-2 mass parts with respect to 100 mass parts of containing silicone raw rubber .

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