Electrophotographic member, heat fixing apparatus, and electrophotographic image forming apparatus

Abstract

The present invention relates to an electrophotographic member, a heat fixing apparatus, and an electrophotographic image forming apparatus. An electrophotographic member includes a base and an elastic layer on the base, the elastic layer including a silicone rubber and metal silicon particles in the silicone rubber; wherein a mass reduction rate of the metal silicon particles is 0.05% or more.

Description

Technical Field

[0001] This disclosure relates to an electrophotographic component used in a thermal fixing apparatus of an electrophotographic image forming apparatus, as well as a thermal fixing apparatus having the electrophotographic component and an electrophotographic image forming apparatus. Furthermore, this disclosure relates to a method for manufacturing the electrophotographic component. Background Technology

[0002] In the thermal fixing apparatus of an electrophotographic image forming device, the pressing section is formed by a heating member and a pressure member configured to face the heating member. When recording material with an unfixed toner image on it is introduced into the pressing section, the unfixed toner is heated and pressurized, the toner melts, and the image is fixed onto the recording material. The heating member is the member that contacts the unfixed toner image on the recording material, and the pressure member is the member configured to face the heating member. The shape of the electrophotographic member is, for example, a rotatable shape such as a roller shape or an annular belt shape. The electrophotographic member may have an elastic layer containing, for example, rubber such as cross-linked silicone rubber and thermally conductive particles on a matrix made of metal or heat-resistant resin.

[0003] In recent years, faster printing speeds and shorter start-up times have been on the rise. Along with this trend, there is a demand for elastic layers with high thermal conductivity and low heat capacity. Japanese Patent Application Publication No. 2007-171946 discloses a heated fixing roller and a heated fixing belt having an elastic layer made of a silicone rubber composition containing metallic silicon particles. However, in order to obtain an elastic layer with higher thermal conductivity, a silicone rubber composition containing a larger amount of metallic silicon particles is used to form the elastic layer, which results in a decrease in the durability of the resulting elastic layer. Summary of the Invention

[0004] At least one aspect of this disclosure aims to provide an electrophotographic component having high thermal conductivity, low heat capacity and excellent durability, as well as a thermal fixing apparatus and an electrophotographic image forming apparatus having the electrophotographic component.

[0005] According to one aspect of this disclosure, an electrophotographic component is provided, comprising: a substrate; and an elastic layer on the substrate, wherein the elastic layer comprises silicone rubber and metallic silicon particles in the silicone rubber; and wherein the mass reduction rate of the metallic silicon particles is 0.05% or more, the mass reduction rate being determined by: (i) collecting 2 g of sample from the elastic layer; (ii) immersing the sample in 50 ml of n-propyl bromide liquid containing dodecylbenzene sulfuric acid at a concentration of 10 wt% at a temperature of 40 °C, and applying ultrasonic waves at 40 kHz for 60 minutes to dissolve the silicone rubber in the sample; (iii) extracting the metallic silicon particles, and then washing the extracted metallic silicon particles three times by vacuum filtration with 10 ml of toluene at a temperature of 25 °C; and (iv) performing thermogravimetric analysis on the metallic silicon particles obtained from step (iii), and measuring the mass reduction rate in a temperature range of 300 °C to 500 °C.

[0006] According to another aspect of this disclosure, a thermal fixing apparatus is provided, comprising a heating member and a pressure member, which heats a recording material having an unfixed toner image thereon at a roller gap formed by the heating member and the pressure member, so as to fix the unfixed toner image onto the recording material, wherein the heating member is the aforementioned electrophotographic member.

[0007] According to another aspect of this disclosure, an electrophotographic image forming apparatus having the aforementioned thermal fixing device is provided.

[0008] According to another aspect of this disclosure, a method for manufacturing an electrophotographic component is provided, comprising:

[0009] An organosilicon component containing organopolysiloxane is mixed with metallic silicon powder, and the resulting mixture is allowed to stand for more than 30 days to prepare a liquid silicone rubber composition.

[0010] A liquid silicone rubber composition is applied to a substrate to form a layer of the composition; and

[0011] The composition is cured to form an elastic layer.

[0012] According to another aspect of this disclosure, a method for manufacturing an electrophotographic component is provided, comprising:

[0013] A liquid silicone rubber composition was prepared by mixing an organosiloxane-containing silicone component with metallic silicon powder using a planetary mixer at a revolution speed of 5 to 15 rpm and a mixing time of 100 to 300 minutes, and allowing the resulting mixture to stand for more than 4 days.

[0014] A liquid silicone rubber composition is applied to a substrate to form a layer of the composition; and

[0015] The composition is cured to form an elastic layer.

[0016] Further features of the invention will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1A and Figure 1B A schematic cross-sectional view of a fixing member according to two aspects of this disclosure is shown. In the figure, Figure 1A A schematic cross-sectional view of a shape-fixing component is shown, and Figure 1B A schematic cross-sectional view of a roller-shaped fixing component is shown.

[0018] Figure 2 A schematic diagram illustrating an example of the surface layer stacking process.

[0019] Figure 3 A schematic cross-sectional view of an example of a heating belt-pressurized belt thermal fixing device is shown.

[0020] Figure 4 A schematic cross-sectional view of an example of a heated belt-pressure roller type thermal fixing device is shown.

[0021] Figure 5 The graph shows the measurement results of the tensile fracture test of Example 1 and Comparative Example 1. Detailed Implementation

[0022] In this disclosure, unless otherwise stated, descriptions indicating a range of values, such as "above XX and below YY" and "XX to YY", refer to a range of values ​​that includes both the lower and upper limits as endpoints. Furthermore, when describing a range of values ​​in segments, any combination of the upper and lower limits of each range is disclosed.

[0023] In this disclosure, the components for electrophotography include, for example, heating components and pressurizing components.

[0024] Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings.

[0025] The reason why elastic layers made from silicone rubber compositions containing a large amount of metallic silicon particles are considered to exhibit lower durability is as follows: The elastic layer of the fixing belt or fixing roller is repeatedly compressed during paper feeding under heating. In particular, the elastic layer is subjected to large deformation and strong compression at the contact point with the paper edge. As the proportion of thermally conductive particles, such as metallic silicon particles, in the elastic layer increases, the proportion of rubber relatively decreases. As a result, the elastic layer is compressed and thus deformed, and the deformation of the rubber portion increases. When the deformation of the rubber portion increases, the stress is particularly concentrated at the interface between the metallic silicon particles and the rubber surrounding the metallic silicon particles, and eventually the rubber portion is damaged. As a method to increase the strength of the interface between the thermally conductive particles and the rubber portion, surface treatment of the metallic silicon particles using a silane coupling agent is considered. However, the surface functional groups of each metallic silicon particle are few, and the effect of surface treatment with a silane coupling agent is considered to be limited.

[0026] Based on the foregoing considerations, further research was conducted, and the inventors discovered that the strength of the interface between the silicon metal particles and the rubber portion can be improved by forming "bound rubber" on the surface of the silicon metal particles. Furthermore, it was found that the elastic layer of the silicon metal particles with bound rubber on the surface exhibits excellent durability.

[0027] Bound rubber is known in the tire industry. That is, in a rubber composition containing rubber and carbon black, bound rubber is observed on the carbon black. Specifically, when carbon black is extracted from an uncured rubber composition containing carbon black using a solvent in which the uncured rubber is soluble, there is rubber that is not extracted due to its binding to the carbon black. The rubber bound to the carbon black is called "bound rubber" (see Japanese Patent Application Publication No. H08-27313).

[0028] The inventors have discovered that in silicone rubber compositions containing metallic silicon particles, a binding rubber can be formed on the metallic silicon particles. Furthermore, as described above, the elastic layer containing metallic silicon particles on which the binding rubber is formed exhibits excellent durability even when a large amount of metallic silicon particles are contained within the elastic layer. The inventors extracted metallic silicon particles from the elastic layer of an electrophotographic component according to this disclosure using a specific extraction method, and measured the amount of silicone rubber still bound to the extracted metallic silicon particles by thermogravimetric analysis, defining the amount of silicone rubber still bound to the extracted metallic silicon particles as the amount of binding rubber. As a result, it was found that the greater the amount of binding rubber, the greater the rupture energy of the elastic layer, and the superior the durability. Therefore, in the elastic layer of an electrophotographic photosensitive component according to one aspect of this disclosure, a large amount of silicone rubber is bound as the binding rubber to the metallic silicon particles. It is believed that as a result, the affinity between the metallic silicon particles and the silicone rubber, which serves as a matrix and in which the metallic silicon particles are dispersed, is improved, and the destruction of the silicone rubber is suppressed at the interface between the metallic silicon particles and the silicone rubber.

[0029] In this disclosure, the amount of bound rubber is defined as the rate of mass reduction within a specific temperature range in the thermogravimetric analysis of metallic silicon particles extracted from the elastic layer (a cured product of the liquid silicone rubber composition) by a specific method.

[0030] In other words, in an electrophotographic component according to one aspect of this disclosure, a "mass reduction rate" of 0.05% or more is the amount of the bonded rubber containing the metallic silicon particles in the elastic layer.

[0031] It is believed that in the elastic layer according to this disclosure, since the mass reduction rate of the metallic silicon particles is 0.05% or more, a large amount of silicone rubber, which serves as the bonding rubber, is in a state bonded to the metallic silicon particles. As a result, the durability of the electrophotographic component including the elastic layer according to this disclosure becomes excellent.

[0032] The following will describe in detail, based on specific components, an electrophotographic component and a thermal fixing apparatus according to one embodiment of the present disclosure.

[0033] (1) Overview of the structure of components for electrophotography

[0034] The components for electrophotography in this embodiment will be described in detail with reference to the accompanying drawings.

[0035] According to one aspect of this disclosure, the electrophotographic component may be, for example, a rotatable component having a roller shape or an annular belt shape (hereinafter also referred to as "fusing roller" or "fusing belt"), respectively.

[0036] Figure 1A A cross-sectional view of the fixing belt in the circumferential direction is shown, and Figure 1BA cross-sectional view of the fixing roller in the circumferential direction is shown. (See diagram below.) Figure 1A and Figure 1B As shown, the electrophotographic component includes a substrate 3, an elastic layer 4 on the outer surface of the substrate 3, and a surface layer (release layer) 6 on the outer surface of the elastic layer 4. Alternatively, an adhesive layer 5 may be provided between the elastic layer 4 and the surface layer 6. In this case, the surface layer 6 is fixed to the outer peripheral surface of the elastic layer 4 by the adhesive layer 5.

[0037] (2) Matrix

[0038] There are no particular restrictions on the material of the substrate, and materials known in the field of electrophotographic components may be used appropriately. Examples of materials constituting the substrate include: metals such as aluminum, iron, nickel, and copper; alloys such as stainless steel; and resins such as polyimide.

[0039] Here, in the case of a thermal fixing device that uses induction heating to heat a substrate as a component for electrophotography, the substrate is formed of at least one metal selected from the group consisting of nickel, copper, iron, and aluminum. Among these metals, alloys containing nickel or iron as the main component are preferred, particularly from the viewpoint of heating efficiency. Note that the main component refers to the component that constitutes the object (here, the substrate) in which it is present the most abundant element.

[0040] The shape of the substrate can be appropriately selected according to the shape of the component for electrophotography, and various shapes can be adopted, such as annular belt shape, hollow cylindrical shape, solid cylindrical shape and film shape.

[0041] In the case of a fixing belt, it is preferable that the thickness of the substrate is, for example, 15 to 80 μm. By setting the thickness of the substrate within the above range, both strength and flexibility can be achieved at a high level.

[0042] Additionally, on the surface of the substrate opposite to the side facing the elastic layer, for example, when the inner circumferential surface of the fixing belt is in contact with other components, a layer for preventing wear on the inner circumferential surface of the fixing belt, or a layer for improving the sliding properties with other components, can be provided.

[0043] (3) Elastic layer

[0044] An elastic layer is a layer used to impart flexibility to electrophotographic components in order to ensure the gap between the fixing rollers in a thermal fixing device. Note that when the electrophotographic component is used as a heating element that contacts toner on paper, the elastic layer also functions as a layer to impart flexibility so that the surface of the heating element can follow the contours of the paper. The elastic layer comprises rubber as a matrix and particles dispersed within the rubber. More specifically, the elastic layer comprises rubber and thermally conductive particles; and is formed by curing a cured product obtained by curing a composition containing at least rubber (a base polymer, a crosslinking agent, etc.) and thermally conductive particles.

[0045] From the viewpoint of the elastic layer performing the aforementioned functions, it is preferable that the elastic layer is formed from a cured product of liquid silicone rubber containing thermally conductive particles, and more preferably from a cured product of an addition-curing liquid silicone rubber composition. The silicone rubber composition may include, for example, thermally conductive particles, a base polymer, a crosslinking agent, a catalyst, and additives as needed. The silicone rubber composition is preferably liquid in many cases because the thermally conductive particles are easily dispersed therein, and the elasticity of the produced elastic layer can be easily adjusted by regulating the degree of crosslinking of the silicone rubber, depending on the type and amount of thermally conductive particles added.

[0046] The matrix is ​​responsible for providing elasticity within the elastic layer. From the viewpoint of the matrix fulfilling this function, it is preferable that the matrix comprises silicone rubber. Silicone rubber is preferred because it exhibits high heat resistance, maintaining flexibility even in areas outside the paper-through portion at temperatures up to approximately 240°C. As the silicone rubber, a cured product of an addition-curing liquid silicone rubber composition, as described later, can be used.

[0047] Liquid silicone rubber compositions typically include the following components (a) to (d).

[0048] Component (a): Organopolysiloxane having unsaturated aliphatic groups;

[0049] Component (b): an organopolysiloxane having active hydrogen atoms bonded to silicon atoms;

[0050] Component (c): catalyst; and

[0051] Component (d): Metallic silicon particles.

[0052] The components are described below. Note that components (a) through (c) can be collectively referred to as the organosilicon components.

[0053] Component (a)

[0054] The organopolysiloxane having unsaturated aliphatic groups is an organopolysiloxane having, for example, unsaturated aliphatic groups such as vinyl groups, and examples of such organopolysiloxanes include organopolysiloxanes represented by the following structural formulas (1) and (2).

[0055]

[0056] In structural formula (1), m 1 Represents an integer greater than or equal to 0, and n 1 Represents integers greater than or equal to 3. Additionally, in structure (1), R... 1 Each independently represents a monovalent unsubstituted or substituted hydrocarbon group that does not contain an unsaturated aliphatic group, provided that R 1 At least one of them represents a methyl group, and R 2 Each can independently represent an unsaturated aliphatic group.

[0057]

[0058] In structural formula (2), n 2 R represents a positive integer. 3 Each independently represents a monovalent unsubstituted or substituted hydrocarbon group that does not contain an unsaturated aliphatic group, provided that R 3 At least one of them represents a methyl group, and R 4 Each can independently represent an unsaturated aliphatic group.

[0059] It does not contain unsaturated aliphatic groups and can be composed of R in structural formulas (1) and (2). 1 and R 3 Examples of monovalent unsubstituted or substituted hydrocarbon groups include the following groups.

[0060] • Unsubstituted hydrocarbon group

[0061] Alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl, and hexyl).

[0062] Aryl (e.g., phenyl).

[0063] • Substituted hydrocarbon group

[0064] Substituted alkyl groups (e.g., chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, 3-cyanopropyl, and 3-methoxypropyl).

[0065] Organopolysiloxanes represented by structural formulas (1) and (2) typically have at least one methyl group directly bonded to a silicon atom forming the chain structure. However, it is preferred that more than 50% of the R... 1 and R 3 Each of the following is a methyl group, and more preferably, all R... 1 and R3 It is methyl because it is easy to synthesize and manipulate.

[0066] R can be derived from structural formulas (1) and (2). 2 and R 4 Examples of unsaturated aliphatic groups include the following groups. Specifically, examples of unsaturated aliphatic groups include vinyl, allyl, 3-butenyl, 4-pentenyl, and 5-hexenyl. Among these groups, R 2 and R 4 Both are preferably vinyl, because they are easy and inexpensive to synthesize and handle, and the crosslinking reaction is easy to carry out.

[0067] From a formability point of view, it is preferable that the viscosity of component (a) is 1000 mm. 2 / s or more and 50000mm 2 / s or less. When the viscosity is 1000 mm 2 At speeds above 50000 mS, the hardness can be easily adjusted to the required hardness of the elastic layer, and when the viscosity is 50000 mS... 2 When the viscosity is below a certain value (e.g., s), the viscosity of the composition becomes a viscosity that is easy to coat. Viscosity (kinematic viscosity) can be measured using a capillary viscometer or rotational viscometer, based on JIS Z 8803:2011.

[0068] Based on the liquid silicone rubber composition used in the formation of the elastic layer, it is preferred that the blending amount of component (a) is 55% by volume or more from the viewpoint of durability and 65% by volume or less from the viewpoint of thermal transfer.

[0069] Component (b)

[0070] Organopolysiloxanes with active hydrogen atoms (Si-H bonds) bonded to silicon atoms react with the unsaturated aliphatic groups of component (a) through the action of a catalyst, and act as crosslinking agents to form cured silicone rubber.

[0071] As component (b), any organopolysiloxane can be used, as long as the organopolysiloxane has Si-H bonds. In particular, from the viewpoint of reactivity with the unsaturated aliphatic groups of component (a), it is suitable to use organopolysiloxanes in which the average number of hydrogen atoms (Si-H bonds) bonded to silicon atoms in one molecule is 3 or more.

[0072] Specific examples of component (b) include linear organopolysiloxanes represented by the following structural formula (3) and cyclic organopolysiloxanes represented by the following structural formula (4).

[0073]

[0074] In structural formula (3), m2 n represents an integer greater than or equal to 0. 3 Represents integers greater than or equal to 3, and R 5 Each can be used independently to represent a monovalent unsubstituted or substituted hydrocarbon group that does not contain an unsaturated aliphatic group.

[0075]

[0076] In structural formula (4), m 3 n represents an integer greater than or equal to 0. 4 Represents integers greater than or equal to 3, and R 6 Each can be used independently to represent a monovalent unsubstituted or substituted hydrocarbon group that does not contain an unsaturated aliphatic group.

[0077] It does not contain unsaturated aliphatic groups and can be derived from R in structural formulas (3) and (4). 5 and R 6 Examples of monovalent unsubstituted or substituted hydrocarbon groups include those represented by R in the above structural formula (1). 1 Similar groups. Among these groups, preferably, more than 50% R 5 and R 6 Each of the following is a methyl group, and more preferably, all R... 5 and R 6 The methyl group is used because it is easy to synthesize and manipulate, and its excellent heat resistance is readily obtained.

[0078] Component (c)

[0079] Examples of catalysts used to form silicone rubber include hydrosilylation catalysts for accelerating the curing reaction. Known substances such as platinum and rhodium compounds can be used as hydrosilylation catalysts. The amount of catalyst blended can be appropriately set and is not particularly limited.

[0080] Component (d)

[0081] The heat capacity per unit volume of metallic silicon particles is approximately 1.7 MJ / m³. 3 • K. This value is less than the approximately 3.0 MJ / m³ heat capacity per unit volume of alumina, which is widely used to improve the thermophysical properties of elastic layers containing silicone rubber. 3 ·K. In addition, the thermal conductivity of metallic silicon particles is as high as approximately 150 W / m·K.

[0082] Preferably, the particle size of the silicon metal particles, in terms of volume average particle size, is in the range of 1 μm to 20 μm. By controlling the volume average particle size within the aforementioned range, a larger number of silicon metal particles can be included in the elastic layer, and the influence of the silicon metal particles on the surface smoothness of the elastic layer can be effectively suppressed. The volume average particle size of the silicon metal particles can be determined using, for example, a laser diffraction scattering type particle size distribution measurement device.

[0083] In addition, to improve the thermal stability, compatibility, and durability of the silicone rubber composition, the metallic silicon particles can be subjected to appropriate surface treatment. Specifically, a surface oxide film can be formed by thermal oxidation or oxidation through water washing.

[0084] Preferably, the blending amount (content) of the metallic silicon particles is controlled to be 35% by volume or more and 45% by volume or less relative to the total volume of the cured product (elastic layer) obtained from the liquid silicone rubber composition. When this amount is 35% by volume or more, the elastic layer can be expected to have high thermal conductivity, and when this amount is 45% by volume or less, the elastic layer can obtain sufficient hardness and strength.

[0085] The content of cured silicone rubber and metallic silicon particles in the elastic layer can be checked using a thermogravimetric analyzer (TGA) (e.g., trade name: TGA / DSC 3+, manufactured by Mettler Toledo International Inc.). The elastic layer is cut with a razor or similar tool to collect a sample of, for example, 20 mg, and the sample is placed in an aluminum dish used in the TGA. The aluminum dish containing the sample is placed in the TGA, and the sample is heated from room temperature to 800°C at a rate of 20°C per minute under a nitrogen atmosphere, and further held at 800°C for 1 hour. By comparing the weights obtained before and after the measurement, the mass-based content of the cured silicone rubber component and metallic silicon particles contained in the elastic layer can be calculated. Furthermore, the content ratio of metallic silicon particles in the elastic layer can be calculated by dividing the mass-based content of metallic silicon particles by the specific gravity of metallic silicon, and by dividing the mass-based content of the cured silicone rubber component by the specific gravity of the cured silicone rubber.

[0086] Alternatively, the content of metallic silicon particles can also be obtained by performing energy dispersive X-ray spectroscopy (EDS) on the cross-section of the elastic layer (e.g., trade name: X-MAXN80, manufactured by Oxford Instruments) and converting the obtained area ratio into a volume ratio.

[0087] Furthermore, the content of metallic silicon particles in such elastic layers can be adjusted by changing the proportion (based on volume) of the metallic silicon particles during the preparation of the liquid silicone rubber composition. In this case, the content of metallic silicon particles can be adjusted by the volume ratio between the organosilicon component (excluding volatile components such as solvents) and the metallic silicon particles.

[0088] In addition to the components described above, the aforementioned liquid silicone rubber composition may, as needed, include reinforcing fillers such as fumed silica, precipitated silica, fused silica, spherical silica obtained by the sol-gel method, and crystalline silica. The liquid silicone rubber composition may further include heat-resistant improvers such as iron oxide or cerium oxide, and reaction control agents such as nitrogen compounds or acetylene compounds. These components may be blended arbitrarily without impairing the effects of this disclosure.

[0089] A liquid silicone rubber composition that can increase the amount of rubber bound to the metallic silicon particles, in other words, a method for preparing a liquid silicone rubber composition that meets the mass reduction rate requirement according to this disclosure, includes the following. Here, in this disclosure, the metallic silicon particles before blending with the liquid silicone rubber component can be referred to as "metallic silicon powder".

[0090] (i) A method of mixing a liquid organosilicon component containing an organopolysiloxane with metallic silicon powder, and then allowing the mixture to stand for an extended period of time.

[0091] (ii) A method of setting the mixing conditions of a liquid organosilicon component containing organopolysiloxane and metallic silicon powder to low shear and long duration.

[0092] The details will be described below.

[0093] (i) A method of mixing a liquid organosilicon component containing an organopolysiloxane with metallic silicon powder, and then allowing the mixture to stand for an extended period of time.

[0094] When a liquid silicone rubber composition containing an organopolysiloxane-based liquid silicone rubber component is allowed to stand, the amount of bound rubber increases over time. By allowing the liquid silicone rubber composition to stand for more than 30 days, the bound rubber is fully formed, and the strength of the cured product is improved. As a method for mixing the liquid silicone rubber component with the metallic silicon powder, for example, a planetary mixer, a rotation / revolutionary mixer, and a kneader can be used. The mixing temperature can be, for example, room temperature of 23 to 25°C, or a high temperature of, for example, 100 to 200°C. When mixing at a high temperature, components (a) and (d) can be pre-mixed to prepare a basic complex, and then other components can be mixed therein. Alternatively, the temperature at which the liquid silicone rubber composition is allowed to stand can be either room temperature or a high temperature.

[0095] The bound rubber formed from the types of rubber used in the tire industry typically forms within hours to days. In contrast, in the silicone rubber composition according to this disclosure, as mentioned above, a longer time is required to form the bound rubber. This is because carbon black, as a filler blended in the rubber used in the tire industry, has a particle size as small as tens of nm, tends to easily form secondary structures, and also has a very large surface area. Therefore, the bound rubber forms on the surface of the carbon black in a relatively short time. On the other hand, compared to carbon black, metallic silicon particles have a larger particle size and a smaller surface area; therefore, it is considered that a longer time is required to form a sufficient amount of bound rubber.

[0096] (ii) A method for mixing a liquid organosilicon component containing an organopolysiloxane with metallic silicon powder under low shear and long duration conditions. Here, metallic silicon is used as the raw material.

[0097] Planetary mixers are frequently used as equipment for mixing liquid organosilicon components containing organopolysiloxanes and metallic silicon powder. The planetary mixer referred to herein is a device with one or more stirring blades, wherein the stirring blades rotate on their own axis and revolve around a central point to impart shear force through planetary motion, thereby mixing the materials.

[0098] Typically, when using a planetary mixer to prepare a liquid silicone rubber composition, the revolution speed can be set to 40 to 200 rpm, the rotation speed to approximately twice the revolution speed, and the mixing time to approximately 5 to 40 minutes. However, according to the inventors' research, it is preferable to set the revolution speed to 5 to 15 rpm, more preferably 8 to 12 rpm, and most preferably an extremely low speed of 10 rpm. Furthermore, it is preferable to set the mixing time to 100 to 300 minutes. After preparing the liquid silicone rubber composition in this manner, the liquid silicone rubber composition is allowed to stand for at least 4 days, preferably about 4 to 6 days. Through this process, a sufficient amount of bound rubber is formed on the silicon metal particles. The reason for this is not yet clear, but it is speculated that the silicone polymer penetrates into the tiny gaps or defects on the surface of the silicon metal particles through capillary action, etc., and forms a sufficient amount of bound rubber. It is believed that due to the increased shear rate, the wetting of the silicone polymer on the surface of the silicon metal particles is not promoted, and the capillary action is reduced, which affects the amount of bound rubber.

[0099] As described above, a method for obtaining a liquid silicone rubber composition according to this disclosure, providing an elastic layer with a mass reduction rate of 0.05% or more, includes: a method for producing a liquid silicone rubber composition comprising the process of mixing an organosilicon component containing an organopolysiloxane with metallic silicon powder, and allowing the resulting mixture to stand for 30 days or more; and a method for producing a liquid silicone rubber composition comprising the process of mixing an organosilicon component containing an organopolysiloxane with metallic silicon powder using a planetary mixer at a revolution speed of 5 to 15 rpm and a mixing time of 100 to 300 minutes, and allowing the resulting mixture to stand for 4 days or more.

[0100] The amount of rubber bound to the silicon metal particles in the elastic layer can be determined by the following steps: (i) collecting 2 g of sample from the elastic layer; (ii) immersing the sample in 50 ml of n-propyl bromide liquid containing 10 wt% dodecylbenzene sulfuric acid at 40 °C and applying ultrasonic waves at 40 kHz for 60 minutes to dissolve the silicone rubber in the sample; (iii) extracting the silicon metal particles and then washing the extracted silicon metal particles three times by vacuum filtration with 10 ml of toluene at 25 °C; and (iv) performing thermogravimetric analysis on the silicon metal particles obtained from step (iii) and measuring the rate of mass reduction in the temperature range of 300 °C to 500 °C.

[0101] Specifically, 2g of a sample containing metallic silicon particles was collected from the elastic layer and immersed in 50ml of n-propyl bromide liquid containing dodecylbenzene sulfuric acid at a concentration of 10wt% at 40°C. For reference, "eSolve 21RS" (trade name, manufactured by Kaneko Chemical Co., Ltd.) was used as the n-propyl bromide liquid. The immersed sample was then washed for 60 minutes under ultrasonic treatment at 40kHz. The cured silicone rubber was dissolved by ultrasonic treatment, and the metallic silicon particles with bound rubber were extracted. Next, the metallic silicon particles were vacuum filtered and washed three times through 10ml of toluene at 25°C using a Kiriyama funnel with a diameter of 40mm and Kiriyama funnel filter paper No. 5C (retaining particles of 1μm), and the resulting metallic silicon particles were separated. Silicone rubber is soluble in toluene; therefore, silicone rubber that was not strongly adsorbed to the metallic silicon particles was removed. The obtained metallic silicon particles were dried at 120°C for 1 hour, and 50 mg of each particle was weighed and measured using TGA. Specifically, the weighed metallic silicon particles were heated from 50°C to 500°C at a rate of 5°C / min under dry air at a flow rate of 80 ml / min, and the mass change was measured. The mass reduction rate (%) in the temperature range between 300°C and 500°C was calculated from the obtained mass change data. The mass change data below 300°C were affected by residual moisture and toluene; therefore, the mass change in the temperature range of 300°C to 500°C was considered as the amount of bound rubber strongly adsorbed onto the metallic silicon powder. In the temperature range of 300 to 500°C, the mass of the individual metallic silicon powder hardly changed, or the metallic silicon powder slightly oxidized and increased in mass. In contrast, for metallic silicon particles strongly adsorbed with silicone rubber, a mass reduction was observed because the silicone rubber decomposed at approximately 300°C. For reference, as a device for TGA measurement, for example, a simultaneous thermogravimetric / differential thermal measurement device (trade name: TGA / DSC 3+, manufactured by Mettler Toledo International Inc.) can be used.

[0102] Regarding the fracture energy of the elastic layer, the elastic layer was cut out using a die (dumbbell-shaped No. 8 as specified in JIS K6251:2004), and the thickness of the rubber near the center of the measurement point was measured. Next, the cut elastic layer was tested using a tensile testing machine (device name: Strograph EII-L1, manufactured by Toyo Seiki Seisaku-sho, Ltd.) at room temperature at a tensile speed of 500 mm / min until the sample fractured. The fracture energy was calculated from the fracture curve. The fracture energy was calculated as the average of four samples.

[0103] (4) Adhesive layer

[0104] The adhesive layer is used to bond the elastic layer and the surface layer. The adhesive used for the adhesive layer can be suitably selected and used from known adhesives, and there are no particular limitations. However, from a handling point of view, it is preferable to use an addition-curing silicone rubber containing a self-adhesive component. This adhesive may contain, for example, a self-adhesive component, an organopolysiloxane having multiple unsaturated aliphatic groups represented by vinyl groups in its molecular chain, a hydrogenated organopolysiloxane, and a platinum compound used as a crosslinking catalyst. By curing the adhesive already applied to the surface of the elastic layer through an addition reaction, an adhesive layer bonding the surface layer to the elastic layer can be formed.

[0105] Note that examples of the self-adhesive components mentioned above include the following substances.

[0106] • A silane having at least one, preferably two or more, functional groups selected from the group consisting of, for example, vinyl alkenyl, (meth)acryloyloxy, silyl hydride (SiH), epoxy, alkoxysilyl, carbonyl, and phenyl.

[0107] • For example, organosilicon compounds such as cyclic or linear siloxanes having 2 or more but less than 30 silicon atoms, and preferably 4 or more but less than 20 silicon atoms.

[0108] • Non-silicon-based organic compounds that may contain oxygen atoms in their molecules (specifically, those that do not contain silicon atoms in their molecules). However, the organic compound contains one or more, but less than four, preferably one or more but less than two, aromatic rings such as a phenylene structure in one molecule. The valence of the phenylene structure is 1 or more but less than 4, and preferably 2 or more but less than 4. Furthermore, the molecule contains at least one functional group (e.g., alkenyl and (meth)acryloyloxy) that can facilitate hydrosilylation addition reactions, and preferably two or more but less than four functional groups.

[0109] The aforementioned self-adhesive components can be used alone or in combination with one or more other components. Furthermore, from the viewpoint of adjusting viscosity and ensuring heat resistance, filler components can be added to the adhesive to the extent permitted by the spirit of this disclosure. Examples of filler components include the following substances.

[0110] • Silicon dioxide, aluminum oxide, iron oxide, cerium oxide, cerium hydroxide, and carbon black, etc.

[0111] There are no particular restrictions on the blending amounts of the components contained in the adhesive, and these amounts can be set appropriately.

[0112] Such addition-curing silicone rubber adhesives are commercially available and readily obtained. Preferably, the thickness of the adhesive layer is 20 μm or less. Because the thickness of the adhesive layer is set to 20 μm or less, when the electrophotographic component according to this aspect is used as a heating belt for a thermal fixing device, the heat resistance can be easily set to be low, and heat from the inner surface side can be effectively transferred to the recording material.

[0113] (5) Surface layer

[0114] Preferably, the surface layer comprises a fluoropolymer resin so that the electrophotographic component functions as a release layer to prevent toner from adhering to the outer surface. For example, the surface layer can be formed by forming the component into a tubular shape using the resin described below.

[0115] • Tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA), polytetrafluoroethylene (PTFE), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP), etc.

[0116] Among the aforementioned resin materials, PFA is particularly preferred from the viewpoint of moldability and release properties of the toner.

[0117] Preferably, the thickness of the surface layer is 10 μm or more and 50 μm or less. When the thickness of the surface layer is controlled within this range, it is easy to maintain appropriate surface hardness of the component for electrophotography.

[0118] (6) Manufacturing method of components for electrophotography

[0119] The electrophotographic component according to this disclosure can be manufactured, for example, by a manufacturing method including the following processes.

[0120] • Preparation process of the substrate

[0121] Prepare the aforementioned substrate and, as needed, fix it to a clamp or similar fixture to maintain its shape.

[0122] The surface of the substrate facing the elastic layer can be treated to impart functions such as adhesion to the elastic layer. Examples of surface treatments include physical treatments such as sandblasting, grinding, and polishing; and chemical treatments such as oxidation, coupling agent treatment, and primer treatment. Furthermore, physical and chemical treatments can be used in combination.

[0123] In particular, it is preferred to treat the outer surface of the substrate with a primer to improve the adhesion between the substrate and the elastic layer, since the elastic layer to be used contains cross-linked silicone rubber. As a primer, for example, a primer in a coating state in which additives are suitably blended and dispersed in an organic solvent can be used. Such primers are commercially available. Examples of the aforementioned additives include silane coupling agents, organosilicon polymers, hydrogenated methylsiloxanes, alkoxysilanes, catalysts that promote reactions such as hydrolysis, condensation, and addition, and colorants such as iron oxide. The primer is applied to the outer surface of the substrate and subjected to drying and calcination; thus, the primer treatment is completed.

[0124] The primer can be appropriately selected based on factors such as the material of the substrate, the type of elastic layer, and the reaction mode during crosslinking. For example, when the material constituting the elastic layer contains a large number of unsaturated aliphatic groups, it is preferable to use a material containing hydrosilyl groups as the primer so as to impart adhesion through reaction with the unsaturated aliphatic groups. On the other hand, when the material constituting the elastic layer contains many hydrosilyl groups, it is preferable to use a material containing unsaturated aliphatic groups as the primer. In addition to the above, the primer can be appropriately selected based on factors such as the substrate containing alkoxy groups as the adherend and the type of elastic layer.

[0125] • Elastic layer formation process

[0126] The process of forming an elastic layer may include the following steps.

[0127] (i) The preparation process of the above liquid silicone rubber composition.

[0128] (ii) A process of applying the composition onto a substrate by means such as blade coating, nozzle coating, or ring coating to form a layer of the composition.

[0129] (iii) A process of curing the composition to form an elastic layer.

[0130] Adhesive layer formation process

[0131] Figure 2 A schematic diagram is shown, illustrating an example of a process in which a surface layer 6 is laminated onto an elastic layer 4 containing silicone rubber via an adhesive layer 5 formed using an addition-curing silicone rubber adhesive. First, the adhesive is applied to the surface of the elastic layer 4 formed on the outer peripheral surface of the substrate 3. Regarding the adhesive, the description in the aforementioned adhesive layer (4) applies to the composition of the components contained in the adhesive, as well as the amounts of the adhesive and blended components.

[0132] By curing the adhesive applied to the surface of the elastic layer through an addition reaction, an adhesive layer that bonds the surface layer to the elastic layer can be formed.

[0133] Preferably, the thickness of the adhesive layer is 20 μm or less. Because the thickness of the adhesive layer is set to 20 μm or less, when the electrophotographic component according to this aspect is used as a heating band in a thermal fixing device, the heat resistance can be easily set to be low, and heat from the inner surface side can be effectively transferred to the recording medium.

[0134] Furthermore, the outer surface of the adhesive layer is covered with a fluoropolymer tube for forming the surface layer 6, and thus the layers are stacked. Note that the adhesion can be improved by pre-treating the inner surface of the fluoropolymer tube with sodium, excimer laser, or ammonia. The fluoropolymer tube can be made of the material and thickness shown in (5) above.

[0135] Preferably, the thickness of the surface layer is 10 μm or more and 50 μm or less. When the thickness of the surface layer is controlled within this range, it is easy to maintain appropriate surface hardness of the component for electrophotography.

[0136] There are no particular limitations on the coating method for the fluoropolymer tube, and suitable methods include coating the elastic layer using an addition-curing silicone rubber adhesive as a lubricant, and coating the elastic layer from the outside with an expanded fluoropolymer tube. Furthermore, any remaining addition-curing silicone rubber adhesive between the elastic layer 4 and the surface layer 6 formed from the fluoropolymer tube can be removed by extrusion using a unit not shown. From a thermal transfer point of view, it is preferable that the thickness of the extruded adhesive layer 5 is 20 μm or less.

[0137] Next, the addition-curing silicone rubber adhesive is cured and bonded by heating for a predetermined time using a heating unit such as an electric furnace, thereby forming the adhesive layer 5 and the surface layer 6 on the elastic layer 4. For reference, conditions such as heating time and heating temperature can be appropriately set according to the adhesive used. The obtained component is cut to the desired length at both ends in the width direction, thereby obtaining a component for electrophotography.

[0138] The following will describe in detail, based on its specific configuration, a thermal fixing device manufactured using an electrophotographic component having an elastic layer having the present disclosure.

[0139] Thermal fixing equipment

[0140] The thermal fixing apparatus of this disclosure is constructed such that rotating bodies, such as a pair of heating rollers and rollers, belts and rollers, and belts and belts, are pressed against each other. Taking into account conditions such as the processing speed and size of the entire electrophotographic image forming apparatus on which the thermal fixing apparatus is installed, the type of thermal fixing apparatus is appropriately selected.

[0141] In a thermal fixing apparatus, heated and pressurized components press against each other to form a fixing roller gap. This gap clamps and conveys an image formed by unfixed toner, which serves as the recording medium to be heated. The image formed by the unfixed toner is called a toner image. The toner image is heated and pressurized through the fixing roller gap of the thermal fixing apparatus. As a result, the toner image melts and the colors mix; subsequently, the resulting toner image is cooled and thus fixed onto the recording medium as an image.

[0142] Specific examples of thermal fixing equipment will be described below with reference to the accompanying drawings, but the scope and application of this disclosure are not limited thereto.

[0143] Heating belt-pressurized thermal fixing equipment

[0144] Figure 3 A schematic cross-sectional view of an example of a thermal fixing device is shown, which is a so-called dual-belt thermal fixing device, wherein rotating bodies such as a pair of heating belts 11 and pressure belts 12 are pressed together, and the device has heating belts as heating elements. Here, the width direction of the thermal fixing device or the components constituting the thermal fixing device is perpendicular to the... Figure 3 The orientation of the paper. The front of the thermal fixing equipment is the side facing inlet of the recording medium S. Left and right refer to the left and right sides when viewed from the front. The width of the tape is the dimension of the tape in the left-right direction when viewed from the front. The width of the recording medium S is the dimension of the recording medium in the direction orthogonal to the transport direction. Furthermore, upstream or downstream refers to upstream or downstream relative to the transport direction of the recording medium (arrow direction).

[0145] The thermal fixing device includes a heating belt 11 and a pressure belt 12, which serve as fixing components. For example... Figure 1A As shown, the heating belt 11 and the pressure belt 12 are each a flexible heating belt consisting of a matrix formed of a metal containing nickel as the main component; and are stretched between two rollers.

[0146] The heating band 11 uses a heating source (induction heating element 13, excitation coil) as the heating unit, which can heat the heating band through electromagnetic induction with high energy efficiency. The induction heating element 13 includes an induction coil 13a, an excitation core 13b, and a coil holder 13c that holds the coil and the core. The induction coil 13a uses flat, elliptical Litz wire wound in the shape of an ellipse, and is arranged in a transverse E-shaped excitation core 13b with protrusions on both sides of the center of the induction coil 13a. By using a material with high permeability and low remanent magnetic flux density, such as ferrite or permalloy, as the excitation core 13b, the losses of the induction coil 13a and the excitation core 13b are suppressed, and the heating band 11 can be heated effectively.

[0147] When a high-frequency current flows from the excitation circuit 14 to the induction coil 13a of the induction heating member 13, the substrate of the heating band 11 generates induced heat, and the heating band 11 is heated from the substrate side. The surface temperature of the heating band 11 is detected by a temperature sensing element 15, such as a thermistor. The signal related to the temperature of the heating band 11 detected by the temperature sensing element 15 is sent to the control circuit 16. The control circuit 16 controls the power supplied from the excitation circuit 14 to the induction coil 13a, so that the temperature information sent from the temperature sensing element 15 is maintained at a predetermined fixing temperature, and thereby adjusts the temperature of the heating band 11 to the predetermined fixing temperature.

[0148] The heating belt 11 is stretched by rollers 17 and 18, which are rotating components. Rollers 17 and 18 are rotatably supported between a left side plate and a right side plate (not shown) of the device.

[0149] Roller 17 is, for example, a hollow roller made of iron with an outer diameter of 20 mm, an inner diameter of 18 mm, and a thickness of 1 mm, and serves as a tension roller to impart tension to the heating belt 11. Heating side roller 18 is, for example, a highly slippery elastic roller with a silicone rubber layer as an elastic layer provided on a core metal made of iron alloy with an outer diameter of 20 mm and an inner diameter of 18 mm.

[0150] The driving force is input from the drive source (motor) M via a drive gear train (not shown) to the heating side roller 18, which serves as the drive roller, and the roller is driven to rotate clockwise at a predetermined speed as indicated by the arrow. The heating side roller 18 is provided with an elastic layer as described above, thereby ensuring that the driving force input to the heating side roller 18 can be satisfactorily transmitted to the heating belt 11, and also forming a fixing roller gap to ensure separation of the recording medium from the heating belt 11. Because the elastic layer is provided on the heating side roller 18, heat conduction to the heating side roller is reduced, resulting in a shorter preheating time.

[0151] When the heating side roller 18 is rotated, the heating belt 11 rotates together with the roller 17 due to the friction between the surface of the elastic layer of the heating side roller 18 and the inner surface of the heating belt 11. The configuration and size of the roller 17 and the heating side roller 18 are selected to match the size of the heating belt 11.

[0152] For example, the dimensions of the roller 17 and the heating side roller 18 are selected such that the heating belt 11, which has an inner diameter of 55 mm when the heating belt 11 is not installed, can be stretched.

[0153] The pressure belt 12 is stretched by the tension roller 19 and the pressure side roller 20, which are rotating components. When not installed, the inner diameter of the pressure belt is, for example, 55 mm. The tension roller 19 and the pressure side roller 20 are each freely rotatably supported between the left and right side plates of the device (not shown).

[0154] Tension roller 19, for example, has a core metal made of iron alloy with an outer diameter of 20 mm and an inner diameter of 16 mm, and has a silicon sponge layer disposed on the core metal to reduce thermal conductivity and reduce heat conduction from pressure belt 12. Pressure side roller 20, for example, is a rigid roller made of iron alloy with an outer diameter of 20 mm, an inner diameter of 16 mm, and a thickness of 2 mm, and has low slippage. The dimensions of tension roller 19 and pressure side roller 20 are also selected to match the dimensions of pressure belt 12.

[0155] Here, the pressure side roller 20 is pressurized toward the heating side roller 18 in the direction of arrow F by a predetermined pressure caused by a pressure mechanism (not shown). The pressure mechanism operates at both ends of the rotating shaft of the pressure side roller 20 to form a roller gap N between the heating belt 11 and the pressure belt 12.

[0156] Additionally, a pressure pad is employed to achieve a wide roll gap N without increasing the size of the equipment. Specifically, the pressure pad includes a fixing pad 21, which serves as a first pressure pad for pressing the heating belt 11 toward the pressure belt 12, and a pressure pad 22, which serves as a second pressure pad for pressing the pressure belt 12 toward the heating belt 11. The fixing pad 21 and the pressure pad 22 are supported and disposed between a left side plate and a right side plate (not shown) of the equipment. The pressure pad 22 applies pressure toward the fixing pad 21 in the direction of arrow G by a predetermined pressure generated by a pressure mechanism (not shown). The fixing pad 21, serving as the first pressure pad, includes a pad base and a sliding piece (low-friction piece) 23 that contacts the belt. The pressure pad 22, serving as the second pressure pad, also has a pad base and a sliding piece 24 that contacts the belt. This is because there is a problem of increased wear on the portion that rubs against the inner circumferential surface of the pad's belt. Since the sliding plates 23 and 24 are inserted between the belt and the pad substrate, wear of the pad can be prevented and sliding resistance can be reduced, thus ensuring satisfactory belt run-through and belt durability.

[0157] For reference, a non-contact eliminator brush (not shown) is provided for the heating belt 11, and a contact eliminator brush (not shown) is provided for the pressurizing belt.

[0158] The control circuit 16 drives the motor M at least when image formation is performed. This drives the heating side roller 18 to rotate and the heating belt 11 to rotate in the same direction. The pressure belt 12 is driven by the heating belt 11 and thus rotates. Here, the roller pair 18 and 20 are configured to clamp and transport the heating belt 11 and the pressure belt 12 at the downstream portion of the fixing roller gap, thereby preventing belt slippage. The downstream portion of the fixing roller gap is where the pressure distribution (along the transport direction of the recording medium) becomes greatest.

[0159] While the heating belt 11 is raised and maintained at a predetermined fixing temperature (referred to as temperature control), the recording medium S, bearing an unfixed toner image t, is conveyed to the roller gap N (arrow direction) between the heating belt 11 and the pressure belt 12. The recording medium S is introduced with the surface bearing the unfixed toner image t facing the heating belt 11. Then, the recording medium S is clamped and conveyed with the unfixed toner image t in close contact with the outer peripheral surface of the heating belt 11, thereby imparting heat and applying pressure from the heating belt 11; and fixing the unfixed toner image t onto the surface of the recording medium S. At this time, heat from the heated substrate of the heating belt 11 is effectively transferred toward the recording medium S through an elastic layer having increased thermal conductivity in the thickness direction. Subsequently, the recording medium S is separated from the heating belt by the separation member 25 and conveyed (in the arrow direction).

[0160] Heating belt-pressure roller type thermal fixing equipment

[0161] Figure 4 This diagram illustrates an example of a heating belt-heating roller type thermal fixing device that uses a ceramic heater as the heating element. Figure 4 In the accompanying drawings, reference numeral 11 indicates a cylindrical or annular belt-shaped heating belt, which may employ a fixing member according to this disclosure. A heat-resistant and heat-insulating belt guide 30 is provided to hold the heating belt 11. At the position in contact with the heating belt 11 (approximately the center of the lower surface of the belt guide 30), a ceramic heater 31 for heating the heating belt 11 is mounted into a groove formed and provided along the length direction of the guide and is fixedly supported. Furthermore, the heating belt 11 is loosely mounted around the belt guide 30. Additionally, a rigid support 32 for pressurization is inserted into the inside of the belt guide 30.

[0162] On the other hand, the pressure roller 33 is configured to face the heating belt 11. Note that in this disclosure, the pressure roller 33 is an elastic pressure roller, specifically, a roller in which an elastic layer 33b of silicone rubber is disposed on a core metal 33a to reduce hardness. The core metal 33a is configured such that its two ends are rotatably held between plates (not shown) on the front and rear chassis sides of the device. For reference, the elastic pressure roller is coated with a PFA (tetrafluoroethylene / perfluoroalkyl ether copolymer) tube to improve surface properties.

[0163] Compression springs (not shown) are respectively disposed in a compressed state between the two ends of the pressure rigid bracket 32 ​​and the spring receiving member (not shown) on the equipment chassis side, thereby applying a downward thrust to the pressure rigid bracket 32. As a result, the lower surface of the ceramic heater 31, which is disposed on the lower surface of the guide member 30 made of heat-resistant resin, presses against the upper surface of the pressure roller 33, while holding the heating belt 11 therebetween, and forming the fixing roller gap N.

[0164] The pressure roller 33 is driven to rotate counterclockwise as indicated by the arrow via a drive unit (not shown). The rotational force generated by the rotation of the pressure roller 33 acts on the heating belt 11 due to the friction between the pressure roller 33 and the outer surface of the heating belt 11. The inner surface of the heating belt 11 is in close contact with the lower surface of the ceramic heater 31 at the fixing roller gap N. Then, the heating belt 11, which is in close contact with the lower surface of the ceramic heater 31, rotates around the belt guide 30 in a clockwise direction as indicated by the arrow at a circumferential speed approximately corresponding to the rotational speed of the pressure roller 33, while sliding in close contact (pressure roller drive mode).

[0165] The pressure roller 33 begins to rotate based on the printing start signal, and the ceramic heater 31 begins to heat. As the pressure roller 33 rotates, the circumferential speed of the heating belt 11 stabilizes, and the temperature of the temperature sensing element 34, located on the upper surface of the ceramic heater, rises to a predetermined temperature, for example, 180°C. At this time, a recording medium S, which is the material to be heated and carries an unfixed toner image t, is introduced into the space between the heating belt 11 and the pressure roller 33 at the fixing roller gap N, in the direction of the arrow, with the toner image carrying surface facing the heating belt 11. Then, the recording medium S, in the fixing roller gap N, comes into close contact with the lower surface of the ceramic heater 31 via the heating belt 11, and moves and passes through the fixing roller gap N together with the heating belt 11. During this movement and passage, the heat of the heating belt 11 is applied to the recording medium S, and the toner image t is heated and fixed on the surface of the recording medium S. The recording medium S, passing through the fixing roller gap N, separates from the outer surface of the heating belt 11 and is then conveyed.

[0166] The ceramic heater 31, serving as the heating element, is a horizontally long, linear heating element with low heat capacity, whose length direction is orthogonal to the moving direction of the heating band 11 and the recording medium S. Preferably, the ceramic heater 31 has a structure that basically includes: a heater substrate 31a; a heating layer 31b disposed along the length direction on the surface of the heater substrate 31a; a protective layer 31c further disposed thereon; and a sliding member 31d. Here, the heater substrate 31a can be formed of aluminum nitride or the like. The heating layer 31b can be formed by applying, for example, a resistive material such as Ag / Pd (silver / palladium) with a width of 1 to 5 mm for about 10 μm by means of screen printing or the like. The protective layer 31c can be formed of glass or fluororesin or the like. Note that the ceramic heater used in thermal fixing equipment is not limited to the above structure.

[0167] Then, an electric current is applied between the two ends of the heating layer 31b of the ceramic heater 31, thereby heating the heating layer 31b and causing the temperature of the heater 31 to rise rapidly. The ceramic heater 31 is fixed and supported by being installed in a groove formed along the length of the guide member with the protective layer 31c facing upwards and disposed in approximately the center of the lower surface of the guide member 30. When the fixing roller gap N contacts the heating belt 11, the surface of the sliding member 31d of the ceramic heater 31 and the inner surface of the heating belt 11 slide while in contact with each other.

[0168] As described above, in the heating belt 11, the thermal conductivity of the elastic layer containing silicone rubber is improved in the thickness direction, and the hardness is also reduced. Due to this configuration, the heating belt 11 can effectively heat the unfixed toner image and fix a high-quality image onto the recording medium S during the fixing roller gap because of its low hardness.

[0169] According to one aspect of this disclosure, an electrophotographic component with high thermal conductivity, low heat capacity, and excellent durability can be obtained. Additionally, according to one aspect of this disclosure, a thermal fixing apparatus that facilitates the stable formation of high-quality electrophotographic images can be obtained. Furthermore, according to another aspect of this disclosure, an electrophotographic image forming apparatus capable of stably forming high-quality electrophotographic images can be obtained.

[0170] Example

[0171] The present disclosure will now be described in more detail with reference to embodiments.

[0172] [Example 1]

[0173] Preparation of liquid silicone rubber composition

[0174] First, as component (a), 100 parts by mass of an organosilicon polymer (hereinafter referred to as "Vi") is prepared, which has vinyl groups as unsaturated aliphatic groups only at both ends of the molecular chain, and has methyl groups as unsubstituted hydrocarbon groups that do not contain other unsaturated aliphatic groups. As Vi, the trade name DMS V41 manufactured by Gelest, Inc. is used, and its viscosity is 10000 mm. 2 / s. For reference, the organosilicon polymer is in which, in structural formula (2), all R 3 It is methyl and all R 4 It is a polymer of vinyl groups.

[0175] Subsequently, Vi was blended with surface-oxidized metallic silicon powder (trade name: M-Si#350WB, manufactured by Kinsei Matec Co., Ltd., with an average particle size of 12 μm) as component (d), such that the volume percentage relative to the organosilicon component was 42%. The mixture was placed in a rotation / revolution mixer (model ARV-310, manufactured by Thinky Corporation) and stirred and mixed at 2000 rpm for 4 minutes to obtain mixture 1.

[0176] Subsequently, mixture 1 was left to stand at room temperature for 180 days.

[0177] Next, the following materials were weighed: 0.22 parts by mass of an IPA solution of 90% 1-ethynyl-1-cyclohexanol (manufactured by Tokyo Chemical Industry Co., Ltd.) as a curing delay agent; 0.1 parts by mass of the hydrogenation silylation catalyst (platinum catalyst: a mixture of 1,3-divinyltetramethyldisiloxane platinum complex, 1,3-divinyltetramethyldisiloxane, and 2-propanol) as component (c); and further, as component (b), an organosilicon polymer having a straight-chain siloxane backbone and having active hydrogen groups bonded to silicon only on the side chains (trade name: HMS-301, manufactured by Gelest Inc., with a viscosity of 30 mm). 2 / s) 1.5 parts by weight; add the weighed material to mixture 1; place the resulting mixture in a rotary / revolutionary mixer (model ARV-310, manufactured by Thinky Corporation) and stir and mix at 600 rpm for 4 minutes under reduced pressure; obtain a liquid silicone rubber composition.

[0178] • Sample preparation

[0179] Using a coating machine (manufactured by Allgood), the above-mentioned liquid silicone rubber composition was coated onto a 50 μm thick stainless steel (SUS) film at a speed of 10 mm / s, resulting in a film thickness of 250 μm. Subsequently, the liquid silicone rubber composition was initially cured by heating at 160°C for 1 minute, and then a secondary curing was performed by heating at 200°C for 30 minutes to prepare a sample sheet of the elastic layer.

[0180] Measurement of mass reduction rate

[0181] Two g of sample was taken from the sample sheet of the aforementioned elastic layer and immersed in 50 ml of n-propyl bromide liquid (trade name: eSolve21RS, manufactured by Kaneko Chemical Co., Ltd.) containing 10 wt% dodecylbenzene sulfuric acid at a temperature of 40 °C. The immersed sample was then washed for 60 minutes under ultrasonic treatment at 40 kHz. This dissolved the cured silicone rubber and extracted the metallic silicon particles. Next, the obtained metallic silicon particles were vacuum filtered three times through 10 ml of toluene at 25 °C using a Kiriyama funnel (40 mm diameter) and Kiriyama funnel filter paper No. 5C (retaining 1 μm particles). The washed metallic silicon particles were dried at 120 °C for 1 hour. The dried metallic silicon particles were weighed in 50 mg amounts and measured using TGA. As a TGA device, "TGA / DSC 3+" (trade name, manufactured by Mettler Toledo International Inc.) was used; and the temperature was increased from 50°C to 500°C at a rate of 5°C / min under dry air at a flow rate of 80 ml / min, and the mass change was measured during this process. The mass reduction rate (%) was calculated from the mass change data obtained within the temperature range between 300°C and 500°C. The results are shown in Table 1.

[0182] • Measurement of fracture energy

[0183] Test pieces were cut from the sample sheet of the above elastic layer using a die (dumbbell-shaped No. 8 as specified in JIS K6251:2004), and the thickness of the rubber near the center of the measurement point was measured. Next, the cut test pieces were tested using a tensile testing machine (device name: Strograph EII-L1, manufactured by Toyo Seiki Seisaku-sho, Ltd.) at room temperature and a tensile speed of 500 mm / min until the sample broke. The fracture energy was calculated from the fracture curve. The fracture energy was calculated as the average of four samples cut from the same sample sheet. The results are shown in Table 1.

[0184] [Comparative Example 1]

[0185] Except that the static storage period was set to 6 days, the sample pieces were prepared in the same manner as in Example 1.

[0186] [Example 2]

[0187] In addition to using a viscosity of 5000mm 2The material of / s (trade name: DMS V35, manufactured by Gelest Inc.) was used as component (a), and the amount of metallic silicon in component (d) was set to 40% by volume, and the standing storage period was set to 46 days, in the same manner as in Example 1.

[0188] [Comparative Example 2]

[0189] Except that the static storage period was set to 3 hours, the sample pieces were prepared in the same manner as in Example 2.

[0190] [Example 3]

[0191] The silicone polymer used as component (a) was changed to one with a viscosity of 20,000 mm, manufactured by Gelest, Inc. 2 / s trade name: DMS-V42. For reference, the organosilicon polymer is in which, in structural formula (2), all R 3 It is methyl and all R 4 It is a polymer of vinyl groups.

[0192] Subsequently, surface-oxidized metallic silicon powder (trade name: M-Si#350WB, manufactured by KinseiMatec Co., Ltd., with an average particle size of 12 μm) was added to Vi as component (d), making the volume percentage relative to the organosilicon component 40%. The mixture was placed in a planetary mixer (Hivis Mix 2P-01 type, manufactured by Primix Corporation) and stirred and mixed at 10 rpm for 160 minutes, resulting in mixture 2. Mixture 2 was then stored at room temperature for 5 days.

[0193] The subsequent steps are the same as in Example 1, and sample sheets are prepared.

[0194] [Comparative Example 3]

[0195] Except that the mixture of components (a) and (d) was placed in a rotation / revolution mixer (model ARV-310, manufactured by Thinky Corporation) in the same manner as in Example 1, and stirred and mixed at 2000 rpm for 4 minutes, the sample was prepared in the same manner as in Example 3.

[0196] (evaluate)

[0197] For the sample pieces of Examples 1 to 3 and Comparative Examples 1 to 3, the TGA reduction rate and fracture energy were measured by the above method. Figure 5 The fracture test curves for Example 1 and Comparative Example 1 are shown.

[0198] [Table 1]

[0199]

[0200] From the results in Table 1, when comparing the Examples and Comparative Examples, it should be understood that, in any composition, the large TGA reduction rate and the composition with a large amount of bound rubber also show a large breaking energy.

[0201] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be interpreted in the broadest sense to cover all such modifications and equivalent structures and functions.

Claims

1. A component for electrophotography, characterized in that, It includes: Matrix; and the elastic layer on the substrate, The elastic layer comprises silicone rubber and metallic silicon particles in the silicone rubber; wherein the mass reduction rate of the metallic silicon particles is 0.05% or more, and the mass reduction rate is determined by the following: (i) Collect 2g of sample from the elastic layer; (ii) The sample was immersed in 50 ml of n-propyl bromide liquid containing dodecylbenzene sulfuric acid at a temperature of 40°C and subjected to ultrasonic waves at 40 kHz for 60 minutes to dissolve the silicone rubber in the sample. (iii) Extract the silicon metal particles, and then wash the extracted silicon metal particles three times by vacuum filtration with 10 ml of toluene at 25°C; and (iv) Perform thermogravimetric analysis on the silicon metal particles obtained from step (iii) and measure the rate of mass reduction in the temperature range of 300°C to 500°C.

2. The electrophotographic component according to claim 1, wherein the blending amount of the metallic silicon particles is 35% by volume or more and 45% by volume or less relative to the total volume of the elastic layer comprising the silicone rubber.

3. The electrophotographic component according to claim 1 or 2, wherein the particle size of the metallic silicon particles is in the range of 1 μm to 20 μm, measured by volume average particle size.

4. The electrophotographic component according to claim 1 or 2, wherein the electrophotographic component has an annular belt shape or a roller shape.

5. A thermal fixing apparatus comprising a heating element and a pressure element, the thermal fixing apparatus heating a recording material having an unfixed toner image thereon at a roller gap formed by the heating element and the pressure element, to fix the unfixed toner image onto the recording material, characterized in that, The heating element is an electrophotographic element according to any one of claims 1 to 4.

6. An electrophotographic image forming apparatus, characterized in that, It includes the thermal fixing apparatus according to claim 5.

7. A method for manufacturing an electrophotographic component according to any one of claims 1 to 4, characterized in that, It includes: An organosilicon component containing organopolysiloxane is mixed with metallic silicon powder, and the resulting mixture is allowed to stand for more than 30 days to prepare a liquid silicone rubber composition. The liquid silicone rubber composition is applied to a substrate to form a layer of the composition; and The layer of the composition is cured to form the elastic layer.

8. A method for manufacturing an electrophotographic component according to any one of claims 1 to 4, characterized in that, It includes: A liquid silicone rubber composition was prepared by mixing an organosiloxane-containing silicone component with metallic silicon powder using a planetary mixer at a revolution speed of 5 to 15 rpm and a mixing time of 100 to 300 minutes, and allowing the resulting mixture to stand for more than 4 days. The liquid silicone rubber composition is applied to a substrate to form a layer of the composition; and The layer of the composition is cured to form the elastic layer.

Images