CN1831675A - Fixing roller - Google Patents

Abstract

Disclosed is a fixing roller which comprises a core 16 , a porous material layer 22 disposed in surrounding relation to an outer peripheral surface of the core 16 , and a thin-walled metal sleeve 26 covering an outer peripheral surface of the porous material layer 22 . The porous material layer 22 comprises a closed cell-type silicone elastomer. The present invention provides a fixing roller capable of ensuring enhanced durability and maintaining a usable state over long periods under the condition of being actually driven and rotated.

Description

Fusing roller

technical field

The present invention relates to a fixing roller comprising a porous material layer covering the outer peripheral surface of the center and a thin-walled metal sleeve covering the outer peripheral surface of the porous material layer.

Background technique

In an image forming apparatus such as a copying machine, a printer, or a facsimile machine, a fixing device is used to image a target object (transfer member, Unfixed toner formed/supported on photosensitive sheet, dielectric-coated sheet (dielectric-coated sheet, etc.) Heat fuser and squeeze rollers.

In connection with this type of fixing roller, as described in Japanese Unexamined Patent Publication No. 2004-53924 (Patent Publication 1), the assignee of this application provides "A method of manufacturing a fixing roller, It comprises: firstly, preparing a porous body comprising a center and a layer of porous material having at least a closed cell (cell) and around an outer peripheral surface located at the center, and then processing this porous body so that the outer diameter is equal to or larger than the thin wall The inner diameter of the metal; the second step, the adhesive is applied to at least one of the outer peripheral surface of the porous body and the inner peripheral surface of the thin-walled metal sleeve; the third step, the porous body and the thin-walled metal sleeve are contained in In the pressurized container, the pressure is applied to them in such a way that the outer diameter of the porous body is smaller than the inner diameter of the thin-walled metal sleeve; the fourth step is to insert the porous body into the thin-walled metal sleeve in the pressurized container In the fifth step, the sleeve body is taken out from the pressurized container so that the porous body expands so that the outer peripheral surface of the porous body is in close contact with the inner surface of the thin-walled metal sleeve; the sixth step, The adhesive is allowed to cure to bond the porous body and the thin-walled metal sleeve together." This method would produce a fuser roller that can be driven and rotated for a long time. remain available for a period of time.

In the technique disclosed in Patent Publication 1, a foamed silicone rubber sponge (hereinafter, it will be simply referred to as “silicon sponge”) is used as the elastic layer. There are particular problems with this silicon sponge, such as non-uniform cell size and indeterminate shape of the cells. Therefore, in the fixing roller manufactured by the method disclosed in Patent Publication 1, there is a risk of cell collapse in a region deformed by an external force. If cell collapse occurs, the durability of the fixing roller will be deteriorated. Therefore, there is a strong need to solve this problem.

Contents of the invention

In view of the above circumstances, an object of the present invention is to provide a fixing roller which can be driven and rotated for a long time under the condition of actually being driven and rotated without using a silicon sponge as an elastic layer. remain available within.

In order to solve the foregoing problems and achieve the above object, the present invention provides a fixing roller comprising a center and a porous material layer, wherein the porous material layer comprises a closed-cell silicone elastomer (silicone elastomer) prepared from an emulsifier composition. ). The porous material is located around the peripheral surface of the center. The fixing roller further includes a thin-walled metal sleeve covering the outer peripheral surface of the porous material layer.

In the fixing roller of the present invention, the silicone elastomer forming the porous material may have a plurality of cells whose closed cell ratio accounts for 60% or more. Units accounting for 50% or more of the total number of units may each have a diameter of 50 μm or less.

In the above fixing roller, each unit accounting for 50% or more of the total number of units may satisfy the following formula (A):

0≤(m-n)/m≤0.5 ----(A)

Where m represents the maximum diameter of the unit and n represents the minimum diameter of the unit.

In the above fixing roller, each unit accounting for 50% or more of the total number of units may satisfy the following formula (B):

0≤(m-n)/n≤0.5 ----(B)

Where m represents the maximum diameter of the unit and n represents the minimum diameter of the unit.

In addition, the average cell diameter of the silicone elastomer may be 30 μm or less.

In the above fixing roller, the ratio of the closed cells of the silicone elastomer may be 80% or more.

In the above fixing roller, the diameter of each unit may be between 0.1 μm and 70 μm.

In the fixing roller of the present invention, the porous material layer can be prepared using a water-in-oil emulsifier composition, which contains a curable liquid silicone rubber material to form a silicone elastomer, a silicone oil material with surface active functions and water.

The fixing roller of the present invention may include a release layer formed around the outer peripheral surface of the thin-walled metal sleeve.

The upper fuser roll also includes a resilient layer positioned between the release layer and the thin-walled metal sleeve.

The fixing roller of the present invention may include an elastic layer formed on the outer peripheral surface of the thin-walled metal sleeve.

The fixing roller of the present invention may include a release layer formed on the outer peripheral surface of the elastic layer.

In the above fixing roller, the elastic layer may be made of fluororesin.

In this case, a fluororesin may be coated on the outer peripheral surface of the elastic layer.

Alternatively, the fluororesin may be formed into a tube shape and covered on the outer peripheral surface of the elastic layer.

As described above, the present invention provides a fixing roller that can ensure improved durability without using silicon sponge as an elastic layer, and can be used for a long period of time under actual driving and rotation conditions. Hold steady.

In the present invention, the porous body as the elastic layer and the thin-walled metal sleeve are bonded together. This can avoid relative circumferential movement between the outer peripheral surface of the porous material layer and the inner peripheral surface of the thin-walled metal sleeve, thereby reliably preventing damage to the fixing roller due to abrasion or crushing of the outer peripheral surface of the porous material layer. unstable state, thus increasing the reliability of the fuser roller.

In addition, the bonding of the porous body and the thin-walled metal sleeve can also reliably prevent the axial displacement of the inner peripheral surface of the thin-walled metal sleeve relative to the outer peripheral surface of the porous material layer, thereby reliably preventing damage due to stress concentration. This leads to cracks occurring, thereby increasing the reliability of the fixing roller, wherein the stress concentration is caused by the edge of the porous material layer coming into contact with the thin-walled metal sleeve.

Other features and advantages of the invention will become apparent from the drawings and detailed description.

Description of drawings

Fig. 1 is SEM photo, and it has shown the section of the silicone elastomer material obtained in invention example 1;

Fig. 2 is SEM photo, and it has shown the section of the silicone elastomer material obtained in invention example 2;

Fig. 3 is SEM photograph, and it has shown the section of the silicone elastomer material obtained in comparative example 1;

Figure 4 is a fixing device using a fixing roller in an embodiment of the present invention;

5 is a cross-sectional view of a thermal fixing roller using the fixing roller in the embodiment;

6 is a schematic diagram of a manufacturing device for a fixing roller in an embodiment;

7 is a schematic view of the manufacturing apparatus in FIG. 6 in the process of applying an adhesive to the peripheral surface of the porous material in the pressurized container;

FIG. 8 is a schematic illustration of the manufacturing tool of FIG. 6 in the process of forming a sleeve body within a pressurized container;

FIG. 9 is a schematic diagram of a modified example of a fixing device;

10 is a schematic diagram of another modified example of the fixing device, in which the fixing roller is applied to a squeeze roller;

11 is a schematic diagram of a modified example of a fixing device, in which an electromagnetic induction heating device is used as an external heating device for heating a fixing roller;

Fig. 12 is a cross-sectional view of the internal structure of the electromagnetic induction heating device in Fig. 11 .

Detailed ways

Referring to the accompanying drawings, the structure of a fixing roller in one embodiment of the present invention and the steps of a method of manufacturing the fixing roller in one embodiment of the present invention will now be described. In the following description, the fixing roller of the present invention will be described in detail based on the case where it is used as a thermal fixing roller of a two-roller type fixing device.

Description will be given in the following order. First, a non-foamed porous material will be described in detail, and more particularly, a porous material prepared using an emulsifier, which is a characteristic component of a heat-fixing roller of an embodiment of the present invention, will be described. Second, a fixing device equipped with the fixing roller of the embodiment of the present invention will be described, and the structure of the fixing roller of the embodiment of the present invention will be further explained. Finally, a method of manufacturing such a fixing roller will be described.

The structure and composition of the porous material used in the present invention will be described in detail below. Since a publication discloses a sponge-forming composition prepared from an emulsifier, Japanese Laid-Open Patent Publication No. 2005-62534 (Patent Publication 2) will be described before this part of the description.

This Patent Publication 2 discloses a silicone rubber sponge-forming composition, and includes a description of the property of forming cells of fine and uniform size. However, Patent Publication 2 does not describe anything about the shape of the cells in the sponge made of the sponge-forming composition obtained by the technique disclosed here. For example, while the porous material formed by the technique of the present invention described later in detail has a given strength against external force due to the spherical shape of the unit to obtain the effect of high resistance to the collapse of the unit, the patent publication 2 The sponge body disclosed cannot obtain this effect.

In this embodiment, the porous material is a closed unit silicon elastomer porous material. More specifically, the porous material can be described as a material comprising a matrix formed of silicon elastomer, and a plurality of closed cells dispersed/distributed on the matrix.

The silicone elastic porous body material is a substantially closed unitized silicon elastomer porous material, which has a plurality of units with a closed unit rate accounting for 60% or more, and the units accounting for 50% or more of the number of all units respectively have 50 μm or less in diameter.

As will be described in detail below, if the closed cells or the ratio of the number of closed cells to the total number of cells is less than 60%, the strength of the porous material will deteriorate.

In addition, the diameter of each cell of the silicon elastomer porous material is in the range of 0.1 to 70 μm, and may also be in the range of 0.1 to 60 μm. In the silicone elastomer porous material of the present invention, cells having a diameter of 50 µm or less account for 80% or more of the total number of cells.

In the silicone elastomer porous material, each unit accounting for 50% or more of the total number of units satisfies the following formula (A).

(A): 0≤(m-n)/m≤0.5 (where m represents the maximum diameter of the unit, and n represents the minimum diameter of the unit)

Equation (A) is a measure of how close the unit is to an optimal spherical body (spheroid).

In the silicone elastomer porous material, each unit accounting for 50% or more of the total number of units satisfies the following formula (B).

(B): 0≤(m-n)/n≤0.5

In formulas (A) and (B), the maximum diameter "m" represents the maximum distance between two points connected on the cross-sectional profile of each cell of the silicon elastomer porous material and substantially passing through the center of the cell , while the minimum diameter "n" represents the shortest distance between two points connected on the cross-sectional profile of each cell of the silicon elastomer porous material and substantially passing through the center of the cell. More specifically, a scanning electron microscope (SEM) is used to take an image of an arbitrary cross-section of a silicon elastomer porous material, and each cell has a maximum diameter "m" and a minimum diameter "n" within approximately 100 to 250 cells. measurements in the area. This measurement can be done manually by using micrometer calipers. The average diameter of the cells is measured by image processing. For example, the analysis software "V10 for Windows 95 Version 1.3" produced by TOYOBO can be used to complete the image processing work.

The diameter of each cell is equal to the value obtained by dividing the sum of the maximum diameter "m" and the minimum diameter "n" of the cell by 2. It should be understood that when the unit has an optimal spherical shape, the maximum diameter "m" is equal to the minimum diameter "n".

The silicon elastomer porous material has cells with an average diameter of 30 μm or less, or has cells with an average diameter of 10 μm or less.

The porous material of the present invention will have a more uniform cell size as the cell size characteristics of the upper region having approximately 100 to 250 cells more closely approximates that of the entire porous material. In other words, the porous material of the present invention exhibits cell size characteristics (cell size, average cell size, diameter of 50 μm or less) defined by the present invention in a rectangular region having 100 to 250 cells in any section thereof. ratio of the number of cells to the total number of cells, and/or spheroids). It has been confirmed that the cell size properties in an arbitrary cross-sectional area can represent the properties of the entire porous material, for example in an area having a maximum dimension of 160 mm (width) x 400 mm (length) x 15 mm (thickness). Thus, any porous material exhibits the cell size properties defined by the present invention within a rectangular area with 100 to 250 cells.

As previously stated, the silicon elastomer porous material is substantially closed-cell. The ratio of the number of closed cells to the total number of cells of the porous material is expressed by "closed cell ratio". This closed cell ratio can be measured in the following manner with reference to examples. The closed cell ratio of the silicon elastomer porous material of the present invention is 60% or more, and may be 80% or more.

Basically, this silicone elastomer porous material can be prepared using a water-in-oil emulsifier, which can include a liquid silicone rubber material and water that can be cured to form a silicone elastomer. In this case, if the liquid silicone rubber material has low viscosity, the liquid silicone rubber material and water can be sufficiently stirred to form an emulsifier. Then, immediately after stirring, the emulsifier is heated and solidified. Preferably, the silicone elastomer porous material of the present invention is prepared using a water-in-oil emulsifier composition, wherein the emulsifier composition contains a silicone oil material with surface-active functions (surface-active silicone oil material), curable to form silicone elastic solid liquid silicone rubber and water.

The liquid silicone rubber material is not limited to special materials as long as it can be heat-cured to form a silicone elastomer. Preferably, a so-called addition reaction-curable liquid silicone rubber can be used as the liquid silicone rubber material. Addition reaction-curable liquid silicone rubber includes polysiloxane having an unsaturated fatty group as a main component, and reactive hydrogen-containing polysiloxane as a crosslinking agent. In the polysiloxane having an unsaturated aliphatic group, the unsaturated aliphatic group may be introduced as a terminal group or as a side chain group. For example, a polysiloxane having an unsaturated fatty group can be represented by the following formula (1):

In formula (1), R ¹ represents an unsaturated aliphatic group, and R ² represents any group consisting of C ₁ to C ₄ lower alkyl, lower alkyl substituted by fluorine, and phenyl. Usually, a+b=50 to 2000. The unsaturated aliphatic group represented by R ¹ is usually a vinyl group. Each ^R2 is typically methyl.

Reactive hydrogen-containing polysiloxane (hydrogen polysiloxane) acts as a crosslinking agent on polysiloxane having unsaturated aliphatic groups, and has hydrogen atoms (active hydrogen) bonded to silicon atoms in the main chain. Preferably, the reactive hydrogen-containing polysiloxane has three or more hydrogen atoms per molecule. For example, the active hydrogen-containing polysiloxane can be represented by the following formula (2):

In formula (2), R ³ represents a hydrogen atom or a C ₁ to C ₄ lower alkyl group, and R ⁴ represents a C ₁ to C ₄ lower alkyl group. Usually, c+d=8 to 100. The lower alkyl group represented by R ³ or R ⁴ is usually a methyl group.

Liquid silicone rubber materials are commercially available. Among the products sold in the market, polysiloxanes containing unsaturated fatty groups and active hydrogen-containing polysiloxanes, which are additional components of reaction-curable liquid silicone rubber, are sold in separate packages, and are used to cure the two components. The curing catalyst mentioned later is added to the reactive hydrogen-containing polysiloxane as required. It should be understood that the two liquid silicone rubber materials can also be used in combination.

Surface-active silicone oil materials are used as dispersion stabilizers for stably dispersing water in emulsifiers. Specifically, the surface-active silicone oil material has affinity for both water and liquid silicone rubber materials. Preferably, the silicone oil material has a hydrophilic group, such as an ether group. Generally, the silicone oil material has an HLB value of 3 to 13, preferably 4 to 11. More preferably, two ether-modified silicone oils having a difference in HLB value of 3 or more may be used in combination. In this case, preferably, the first ether-modified silicone oil having an HLB value of 7 to 11 may be used in combination with the second ether-modified silicone oil having an HLB value of 4 to 7. Each ether-modified silicone oil has a polyether introduced into a polysiloxane side chain. For example, ether-modified silicone oil can be represented by the following formula (3):

In formula (3), R ⁵ represents a C ₁ to C ₄ lower alkyl group, and R ⁶ represents a polyether group. Usually, e+f=8 to 100. The lower alkyl group represented by R ⁵ is usually a methyl group. The polyether group represented by R ⁶ generally includes a (C ₂ H ₄ O) _X group, a (C ₃ H ₆ O) _Y group, or a (C ₂ H ₄ O) _X (C ₃ H ₆ O) _Y group. The HLB value is primarily determined by the numbers x and y. Surface active silicone oil materials are commercially available.

It should be understood that the water dispersed in the water-in-oil emulsifier as the discontinuous phase is in the form of particles (water droplets). As will be described later, the particle size of each water particle basically determines the diameter of each cell (pore) of the silicone rubber porous material of the present invention.

The water-in-oil emulsifier may include a cure catalyst for curing the liquid silicone rubber material. Platinum catalysts can be used as curing catalysts, as is known. Platinum catalysts may be used at about 1 to 100 ppm (parts per million) by weight to obtain sufficient catalytic effect. The curing catalyst may be added to the water-in-oil emulsifier during the preparation of the silicone elastomer porous material or during the preparation of the water-in-oil emulsifier.

In the above water-in-oil emulsifier, in terms of making the emulsifier obtain particularly excellent performance in the stability of water dispersion, the surface-active silicone oil material and water are preferably relative to 100 parts by weight of the water-in-oil emulsifier They are mixed together with a weight fraction of 0.2 to 5.5 and a weight fraction of 10 to 250, respectively. Emulsifiers with excellent properties in terms of water dispersion stability can be used to prepare more stable and adequately porous materials.

When the surface-active silicone oil is composed of the aforementioned first ether-modified silicone oil and the aforementioned second ether-modified silicone oil, the first ether-modified silicone oil and the second ether-modified silicone oil are preferably relative to 100 parts by weight The liquid silicone rubber material is used in a proportion by weight of 0.15 to 3.5 and in a proportion of 0.05 to 2 (a total of 0.2 to 5.5 proportions by weight). When the liquid silicone rubber material is composed of a combination of unsaturated fatty group-containing polysiloxane and active hydrogen-containing polysiloxane, the weight ratio of the former to the latter is in the range of 6:4 to 4:6.

The silicone elastomer porous material may include various additives to be used according to the intended purpose. Such additives may include colorants (pigments, dyes), conductive materials (carbon black, metal powder, etc.), fillers. These catalysts can be mixed into water-in-oil emulsions. For example, to adjust the viscosity of the emulsifier for ease of degassing, the water-in-oil emulsifier composition may contain a non-reactive silicone oil. It is advantageous to deal with a water-in-oil emulsion whose viscosity is from 1 to 2 cSt because of its ease of degassing.

Water-in-oil emulsions can be prepared by various methods. Water-in-oil emulsions are generally prepared by mixing a liquid silicone rubber material, a surface-active silicone oil material, water, and optional additives, and then stirring the composition thoroughly. When the liquid silicone rubber material is composed of polysiloxane containing unsaturated fatty group and polysiloxane containing active hydrogen, the polysiloxane containing unsaturated fatty group and a part of surface active silicone oil material can be mixed brought together and stirred to obtain a first composition, and then the active hydrogen-containing polysiloxane and remaining surface active silicone oil material were mixed together and stirred to obtain a second composition. Then, the first and second compositions are mixed together while gradually adding water thereto to obtain the desired emulsifier.

It should be understood that the preparation process of the water-in-oil emulsifier is not limited to the above process. The liquid silicone rubber material, surface active silicone oil material, water and optional additives may be mixed together in any suitable order. Stirring for forming the desired water-in-oil emulsifier composition can be accomplished by operating a stirring device rotating, for example, at a revolution number of 300 to 1000 rpm. After the emulsification process is completed, the water-in-oil emulsifier can be degassed by using, for example, a vacuum decompression device, and the air mixed in the emulsifier can be exhausted without heating.

In the process of using the obtained water-in-oil emulsifier to prepare silicone elastomer multiple materials, the water-in-oil emulsifier can be placed under the thermal curing condition of the liquid silicone rubber material (main heating) with the addition of a curing catalyst . Preferably, in order to thermally cure the liquid silicone rubber material in the absence of water vapor in the emulsifier, the main heating process should be performed at a temperature of 130° C. or lower. During the main heating process, the heating temperature is usually 80° C. or higher, and the heating time is usually about 5 to 60 minutes. Through this main heating process, the liquid silicone rubber material is solidified so that the water particles in the emulsifier are confined therein in an emulsified state. The silicone rubber is cured to have strength against expansion force generated during water evaporation in the second heating described below.

Then, in order to remove the water trapped in the cured silicone rubber therefrom, a second heating process is performed. Preferably, the second heating process is performed at a temperature of 70 to 300°C. If the heating temperature is lower than 70°C, it will take a long time to remove the water. If the heating temperature is higher than 300°C, the properties of the cured silicone rubber will deteriorate. With heating at a temperature of 70 to 300°C, the water will be vaporized and removed within 1 to 24 hours. Through the second heating process, the water is vaporized and removed, and the final cure of the silicone rubber material will be obtained. The vaporized/removed water will leave a plurality of cells, where each cell is approximately the same size as a corresponding one of the water particles.

In this way, silicone elastomer porous materials will be prepared using water-in-oil emulsifiers without foaming. In addition, the water particles in the water-in-oil emulsifier will be confined in the silicone rubber being cured by the primary heating process and simply evaporated during the secondary heating process.

The above porous material will be described in more detail in conjunction with several examples below. It should be understood that the porous material of the present invention is not limited to these examples.

In the example below, the enclosed cell proportions will be determined as follows.

<Measurement of Closed Cell Ratio>

The silicon elastomer porous material of the present invention has high surface tension and multiple tiny units. Therefore, water hardly enters therein. From this point of view, surfactants or surfactants are employed to provide silicone elastomer porous materials with enhanced wettability with respect to water.

Specifically, the surface layer (approximately to 1.0 mm from the surface) of the prepared silicone elastomer porous material and the weight of the post-removal porous material (the weight of the porous material before water absorption) were measured. The porous material was immersed in a mixed solution of 100 parts by weight of water and 1 part by weight of a hydrophilic silicone oil [polyether-modified silicone oil (KF-618 produced by Shin-Etsu Chemical Co., Ltd.)], and under reduced pressure Leave it on for 10 minutes. Then, after returning to the atmospheric pressure, the porous material was taken out from the mixed solution, and the water attached to the surface of the porous material was completely wiped off. Then, the weight of the porous material (the weight of the pre-wet absorbed porous material) was measured. The following formulas are used to calculate the absorption rate, the ratio of open cells and the ratio of closed cells in sequence.

Water absorption (%)={(weight of porous material after water absorption-weight of porous material before water absorption)/weight of porous material before water absorption}×100

Open unit ratio (%)=(specific gravity of porous material×water absorption/100)/{specific gravity of mixed solution-(specific gravity of porous material/specific gravity of silicon elastomer)}×100

Proportion of closed units (%) = 100-proportion of open units (%)

In the above formula, the specific gravity of the silicone elastomer is the specific gravity of the silicone elastomer obtained by curing the liquid silicone rubber material, and the specific gravity is stated in the product catalogue.

[Invention Example 1]

In Invention Example 1, liquid silicone rubber (trade name: KE-1353) produced by Shin-Etsu Chemical Co., Ltd. was used as the liquid silicone rubber material. In this liquid silicone rubber, polysiloxane containing active hydrogen (viscosity: 16Pa·S) and polysiloxane containing vinyl (viscosity: 15Pa·S) are provided in separate packages, and polysiloxane containing vinyl The oxane has a catalytic amount of platinum catalyst added thereto. Hereinafter, the former and the latter are referred to as "silicone rubber agent A" and "silicone rubber agent B", respectively. Active hydrogen-containing polysiloxanes have the chemical structure of formula (2), where each R ⁴ is a methyl group. Vinyl-containing polysiloxanes have the chemical structure of formula (1), where each R ¹ is vinyl and each R ² is methyl. In addition, KF-618 (HLB: 11; hereinafter referred to as "dispersion stabilizer I") and KF-6015 (HLB: 4; hereinafter referred to as "dispersion stabilizer II") were used as dispersion stabilizers, Each of them is a polyether-modified silicone oil and is produced by Shin-Etsu Chemical Co., Ltd. The silicone elastomer itself obtained from the liquid silicone rubber material used in Inventive Example 1 had a specific gravity of 1.04 (catalog value).

The composition prepared by mixing the dispersion stabilizer I of 0.7 parts by weight and the dispersion stabilizer II of 0.3 parts by weight was added to the silicone rubber agent A of 50 parts by weight, and the obtained composition was fully mixed with a hand mixer. Stir for 5 minutes to form Compound A. In addition, a composition prepared by mixing 0.7 parts by weight of dispersion stabilizer I and 0.3 parts by weight of dispersion stabilizer II was added to 50 parts by weight of silicone rubber agent B, and the obtained composition was stirred by hand Mix well for 5 minutes to form composition B.

Mix compositions A and B together. The obtained composition was stirred by means of a hand mixer for 3 minutes, while adding 10 parts by weight of water, and stirred for a further 2 minutes. The obtained composition was stirred with a hand mixer while gradually adding 90 parts by weight of water to obtain an emulsifier.

The obtained emulsifier was degassed in a vacuum decompression apparatus to remove mixed air therefrom. Then, the emulsifier was poured into a compression molded part having a depth of 6 mm, and the emulsifier was molded using a pressure plate while feeding at a temperature set at 100° C. for 30 minutes (main heating). The obtained molded body (precursor of the porous material) was heated in a heating furnace at 150° C. for 5 hours (subheating) to remove water therefrom. In this way, a rectangular plate-type silicone elastomer porous test piece having a length of 42 mm, a width of 20 mm and a thickness of 6 mm was prepared. The test piece was cut in the width direction. SEM was used to observe the as-cut surfaces, and the maximum and minimum diameters of each element were measured by micrometer calipers to determine element size properties. In addition, the closed cell ratio of the test piece was also measured. The structures are shown in Table 1 below. As shown by the test results, the specific gravity of the porous elastomer obtained in Example 1 of the present invention was 0.66, and the hardness (Asher-C) was 40. FIG. 1 shows a SEM photograph of the cut surface of the test piece (magnification: ×100). In this way, a closed cell porous material with very fine/uniform cell size is obtained.

[Invention example 2]

In Invention Example 2, liquid silicone rubber (trade name: DY35-7002) produced by Toray Dow Corning Co., Ltd. was used as the liquid silicone rubber material. In this liquid silicone rubber, active hydrogen-containing polysiloxane (viscosity: 15Pa·S) and vinyl-containing polysiloxane (viscosity: 7.5Pa·S) are provided in separate packages, and vinyl-containing polysiloxane The siloxane has a catalytic amount of platinum catalyst added thereto. Hereinafter, the former and the latter are referred to as "silicone rubber agent A" and "silicone rubber agent B", respectively. Active hydrogen-containing polysiloxanes have the chemical structure of formula (2), where each R ⁴ is a methyl group. Vinyl-containing polysiloxanes have the chemical structure of formula (1), where each R ¹ is vinyl and each R ² is methyl. In addition, the aforementioned dispersion stabilizer I and dispersion stabilizer II were used as the dispersion stabilizer. The silicone elastomer itself obtained from the liquid silicone rubber material used in Invention Example 1 had a specific gravity of 1.03 (catalog value).

The composition prepared by mixing the dispersion stabilizer I of 0.7 parts by weight and the dispersion stabilizer II of 0.3 parts by weight was added to the silicone rubber agent A of 50 parts by weight, and the obtained composition was fully mixed with a hand mixer. Stir until composition A is formed. In addition, a composition prepared by mixing 0.7 parts by weight of dispersion stabilizer I and 0.3 parts by weight of dispersion stabilizer II was added to 50 parts by weight of silicone rubber agent B, and the obtained composition was stirred by hand Mix well for 5 minutes to form composition B.

Mix compositions A and B together. The obtained composition was stirred by means of a hand mixer for 3 minutes, while adding 10 parts by weight of water, and stirred for a further 2 minutes. The obtained composition was stirred with a hand mixer while gradually adding 90 parts by weight of water to obtain an emulsifier.

The obtained emulsifier was used in the same manner as Inventive Example 1 to prepare a silicon elastomer porous material test piece, and the cell size was measured to determine the closed cell ratio. The results are shown in Table 1 below. As shown by the test results, the specific gravity of the porous elastomer obtained in Invention Example 2 was 0.55, and the hardness (Asher-C) was 56. FIG. 2 shows a SEM photograph of the cut surface of the test piece (magnification: ×100). In this way, a closed cell porous material with very fine/uniform cell size is obtained.

[Invention Example 3]

In Inventive Example 3, the compositions A and B used in Inventive Example 3 were mixed together. The obtained composition was stirred by means of a hand mixer for 3 minutes, while adding 10 parts by weight of water, and stirred for a further 2 minutes. The obtained composition was stirred with a hand mixer while gradually adding 90 parts by weight of water to obtain an emulsifier.

The obtained emulsifier was used in the same manner as Inventive Example 1 to prepare a silicon elastomer porous material test piece, and the cell size was measured to determine the closed cell ratio. The results are shown in Table 1 below. As shown by the test results, the specific gravity of the porous elastomer obtained in Invention Example 1 was 0.53, and the hardness (Asher-C) was 58. FIG. 2 shows a SEM photograph of the cut surface of the test piece (magnification: ×100). In this way, a closed cell porous material with very fine/uniform cell size is obtained.

[Invention Example 4]

In Invention Example 3, the liquid silicone rubber used in Invention Example 2 and the liquid silicone rubber produced by TorayDow Corning Co., Ltd. (trade name: DY35-615) were used. In liquid silicone rubber DY35-615, polysiloxane containing active hydrogen (viscosity: 113Pa·S) and polysiloxane containing vinyl (viscosity: 101Pa·S) are provided in separate packages, and polysiloxane containing vinyl The polysiloxane has a catalytic amount of platinum catalyst added thereto. Hereinafter, the former and the latter are referred to as "silicone rubber agent A" and "silicone rubber agent B", respectively. Active hydrogen-containing polysiloxanes have the chemical structure of formula (2), where each R ⁴ is a methyl group. Vinyl-containing polysiloxanes have the chemical structure of formula (1), where each R ¹ is vinyl and each R ² is methyl.

A composition prepared by mixing 0.7 parts by weight of dispersion stabilizer I and 0.3 parts by weight of dispersion stabilizer II was added to silicone rubber agent A used in Invention Example 2 mixed together at a volume ratio of 50:50 and the composition of silicone rubber agent A, and the obtained composition was thoroughly stirred by a hand mixer for 5 minutes to form composition A. In addition, a composition prepared by mixing 0.7 parts by weight of dispersion stabilizer I and 0.3 parts by weight of dispersion stabilizer II was added to the silicone rubber used in Invention Example 2 mixed together at a volume ratio of 50:50. In the composition of agent B and silicone rubber agent B, and the obtained composition was thoroughly stirred by a hand mixer for 5 minutes to form composition B.

Mix compositions A and B together. The obtained composition was stirred by means of a hand mixer for 3 minutes, while adding 10 parts by weight of water, and stirred for a further 2 minutes. The obtained composition was stirred with a hand mixer while gradually adding 90 parts by weight of water to obtain an emulsifier.

A silicon elastomer porous material test piece was prepared using the obtained emulsifier in the same manner as Inventive Example 1, and the cell size was measured to determine the closed cell ratio. The results are shown in Table 1 below. The specific gravity of the obtained silicone elastomer itself used in the liquid silicone rubber material in Inventive Example 4 was 1.07. In addition, the specific gravity of the porous material obtained in Inventive Example 4 was 0.60, and the hardness (Asher-C) was 35.

[Comparative example 1]

The extrusion roller was separated from the printer Able1405 produced by Fuji Xerox Co., Ltd., and cut from the elastic layer made of a silicon elastomer porous material (foam prepared using 2,2-azobisisobutyronitrile as a blowing agent) Lower the test piece. The cell size characteristics and closed cell ratio of the test piece were measured in the same manner as Inventive Example 1. Table 1 below shows the results. Fig. 3 shows a SEM photograph of the cut surface of the test piece (magnification: ×100).

Table 1 Cell size characteristics and closed cell ratio of porous materials Element Size Properties of Porous Materials Invention example 1 Invention example 2 Invention example 3 Invention example 4 Comparative example 1 Measuring area(mm ² ) 2.54×10 ^-1 2.66×10 ^-3 9.47×10 ^-3 2.65×10 ^-2 7.51 number of units 179 105 122 250 146 Minimum element size 9.1 1.1 2.3 1.5 40.7 Maximum cell size 60.7 9.1 40.6 12.8 628 Proportion of units satisfying formula (A) (%) 100 100 100 100 65 Proportion of units satisfying formula (B) (%) 95 98.7 90.2 99.8 25 Proportion of units satisfying formulas (A) and (B) at the same time (%) 95 98.7 90.2 99.8 16.3 mn (maximum) twenty one 2.1 3.3 3.9 409 Proportion of units whose diameter is 50 μm or smaller (%) 96 100 100 100 1 average cell size 28 4.7 6.6 4.9 207 Proportion of closed cells (%) 98.4 98.2 99.2 99.7 90.5

(fixing device 10)

A system configuration of a fixing device 10 equipped with a fixing roller using an upper porous material will be described with reference to FIG. 4 . The fixing roller of this embodiment is used as the fixing roller 12 of the heating/rotating member in the fixing device 10 . In FIG. 4 , reference numeral 14 denotes a pressing roller as a pressing member, which is in contact with the fixing roller 12 with a given pressing force and is rotatably driven by the fixing roller 12 . The thermistor 38 is in contact with the outer peripheral surface of the fixing roller 10 to measure the surface temperature of the fixing roller 10 .

The fixing roller 12 is designed to be rotatably driven in the direction indicated by the arrow by a driving device (not shown) through a transmission gear (not shown), wherein the transmission gear is fixed on a metal (such as iron) at the longitudinal end of the drive shaft. The squeeze roller 14 is driven by the fixing roller 12 to be rotationally driven in the direction indicated by the arrow so as to follow the rotation of the fixing roller 12, and at the same time move toward the fixing roller under the action of a pressing spring (not shown) through a bearing (not shown). 12, wherein the bearings are fixed to each opposite longitudinal end of the iron core 18. The reference N designates the nip area of press contact where the rollers 12 , 14 are in contact with each other.

(fixing roller 12)

The fixing roller 12 of this embodiment is made by the manufacturing method described below. As shown separately in FIG. 5 , the fuser roller 12 basically comprises a center 16, a layer of porous material surrounding the center 16 through a primer 20, bonded to the layer of porous material 22 by an adhesive layer 24 to A thin-walled metal sleeve 26 covering the outer peripheral surface of the porous material layer 22 , and a release layer 28 located on the outer peripheral surface of the thin-walled sleeve 26 to cover the outer peripheral surface of the thin-walled sleeve 26 .

In this embodiment, the porous material layer 22 is made of silicon elastomer, wherein the silicon elastomer has at least a plurality of closed cells or a closed cell silicon elastomer, which will be described in detail later. The porous material layer 22 is formed by an outer surface grinding device (not shown) in such a way that the outer diameter of the porous material layer 22 is greater than the inner diameter of the thin-walled metal sleeve 26 before the porous material layer 22 is tightly fitted into the thin-walled metal sleeve 26. processed. In particular, the thin-walled metal sleeve 26 has an inner diameter of 30.0 mm, while the porous material layer 22 is machined to have a pre-insertion diameter of 30.5 mm.

The thin-walled metal sleeve 26 includes a sleeve base 26a made of a highly thermally conductive metal material such as iron, SUS, or nickel. In this embodiment, the sleeve base 26 a is formed as an electroformed sleeve made of nickel with an inner diameter of 30.0 mm and a wall thickness of 10 to 100 μm, preferably 30 to 50 μm. In particular, the sleeve base 26a is formed as a thin-walled sleeve with a wall thickness of 35 μm. Further, silicone rubber is applied on the outer peripheral surface of this sleeve base 26a through a primer to form a silicone rubber layer 26b. Further, the outer peripheral surface of the silicone rubber layer 26 b is covered with a tubular body made of a fluororesin such as a perfluoroalkyl-tetrafluoroethylene copolymer (PFT), wherein the tubular body defines a release layer 28 .

After the silicone rubber was cured, the wall thickness of the silicone rubber layer 26b was set to 200 μm. The wall thickness of the PFA tube defining the release layer 28 is 30 μm. The thickness of the adhesive layer (not shown) bonded to the diameter of the silicone rubber layer 26b and the release layer 28 is about 30 [mu]m. For example, the adhesive used to form the adhesive layer may be a silicone rubber-based adhesive such as two-component LTV (trade name: SE 1700 produced by Toray Dow Corning Co., Ltd.). In addition, RTV (trade name: KE 45 manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used.

The process of preparing this thin-walled metal sleeve 26 will be briefly described below. The sleeve base 26a was prepared by using an electroforming tape production apparatus (not shown), and a primer was applied to the outer peripheral surface of the sleeve base 26a. After the primer had dried, the silicone rubber was applied to the dried primer in such a way that it had a thickness of 200 μm after curing and was then cured.

Then, an adhesive is applied to the outer peripheral surface of the silicone rubber layer 26b defined by the cured silicone rubber in a thickness of about 30 μm, and the PFA tube is installed to cover the silicon rubber in such a manner that it is bonded thereto by the adhesive. Rubber layer 26b. Then, the adhesive is cured to allow the release layer 28 composed of a PFA tube to adhere to the outer peripheral surface of the silicone rubber layer 26b to form a thin-walled metal sleeve. The thin-walled metal sleeve is cut to a given length to prepare the desired thin-walled metal sleeve 26 .

Thus, a thin-walled metal sleeve 26 whose outer peripheral surface is in contact with the release layer 28 can be produced.

To bond the porous material layer 22 and the thin-walled metal sleeve 26 together, an adhesive layer 24 is applied to either of the outer peripheral surface of the porous material layer 22 and the inner peripheral surface of the thin-walled metal sleeve 26 . In this embodiment, the adhesive 24 is applied to the outer peripheral surface of the porous material layer 22 before the thin-walled metal sleeve 26 is mounted on the outer peripheral surface of the porous material layer 22 .

The adhesive used to form the adhesive layer 24 may be a silicone rubber-based adhesive. In this embodiment, the same adhesive as the adhesive bonded between the silicone rubber layer 26b and the release layer 28, a two-component LTV (trade name: SE produced by Toray Dow Corning Co., Ltd.) can be used. 1700). In addition, RTV (trade name: KE 45 manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used.

Preferably, the adhesive layer 24 has a thickness of 200 μm, especially about 50 μm, calculated according to the amount of adhesive applied. If the thickness of the adhesive layer 24 is less than 5 μm, sufficient strength cannot be ensured. If the thickness of the adhesive layer 24 exceeds 200 μm, the heat insulating effect of the porous layer 22 will be undesirably damaged. Therefore, the thickness of the adhesive layer 24 is preferably set between 5 and 200 μm.

The layer of porous material 22 and the thin walled metal sleeve 26 are bonded together in the above manner. In this way, even when the frictional contact force between the thin-walled metal sleeve 26 and the squeeze roller 14 increases under the rotation state of the fixing roller 12, relative rotation between the porous material layer 22 and the thin-walled metal sleeve 26 can be avoided. Thereby, an obvious effect of preventing the fixing roller 12 from becoming unstable due to abrasion or crushing of the outer peripheral surface of the porous material layer 22 is obtained.

In addition, the thin-walled metal sleeve 26 is bonded to the porous material layer 22 in a state where the fixing roller 12 is rotated. This makes it possible to reliably prevent axial displacement of the thin-walled metal sleeve 26 relative to the porous material layer 22, and provides another great effect of reliably preventing breakage phenomena due to stress concentrations, wherein The stress concentrations are due to the axial displacement of the thin-walled metal sleeve 26 relative to the layer of porous material 22 .

If a silicone rubber-based adhesive is used as the adhesive forming the adhesive layer 24, it will be possible to effectively utilize the softness and elasticity given by the adhesive itself. In particular, when bonding the soft porous material layer 22 to the hard thin-walled metal sleeve 26, the adhesive can effectively absorb the difference in hardness between them to provide a significant effect of preventing stress from occurring.

As mentioned above, the adhesive layer 24 having a given elasticity prevents the force from the hard thin-walled metal sleeve 26 from being transmitted to the porous material layer 22 to serve as a so-called protective layer.

In addition, the release layer 28 is made of fluororesin such as PTFE or PFA. For example, PFA may be applied to the outer peripheral surface of the thin-walled metal sleeve 26 , or a PFA tube may be provided to cover the outer peripheral surface of the thin-walled metal sleeve 26 .

In the squeeze roll 14 , a silicone rubber elastic layer 30 is formed around the outer peripheral surface, and then a PTFE or PFA release layer is formed around the outer peripheral surface of the silicone rubber elastic layer 30 .

Reference numeral 34 denotes a halogen heater serving as external heating means for heating the surface of the fixing roller 12 from the outside. The halogen heater 34 is opposed to the fixing roller 12 in the vicinity of the conveyance target entrance of the tension region N of press contact between the fixing roller 12 and the pressing roller 14, and the surface of the fixing roller 12 is heated by the halogen heater. 34' of radiant heat heating.

In order for the radiant heat from the halogen heater 34 to efficiently heat the fixing roller 12, a reflector 36 bent to have a high reflectivity is provided on the other side of the fixing roller 12 while interposing the halogen heater 34 therebetween, Radiant heat from the halogen heater 34 is thereby reflected without diffusion.

The thermistor 38 is provided in contact with the fixing roller 10 to measure the surface temperature thereon, and information on the detected surface temperature of the fixing roller 10 is transmitted to a CPU (not shown) through an A/D converter (not shown). ). Based on this information, a CPU (not shown) operates to controllably turn on/off the halogen heater 34, thereby maintaining the surface temperature of the fixing roller at a given value.

As noted above, the transfix roller 12 has a layer of porous material 22 contained therein and a thin-walled metal sleeve 26 on its outer side. In this way, the thin-walled metal sleeve 26 will be rapidly heated by the heating means (halogen heater) 34 from the outside.

In terms of machinability, the thickness of the thin-walled metal sleeve 26 cannot be set to an extremely small value. In addition, also in the case of focusing on machinability, if the thickness of the thin-walled metal sleeve 26 is excessively increased, the rigidity of the thin-walled metal sleeve 26 will increase to make it difficult to sufficiently obtain clamping of the clamping region N. width. Therefore, the thickness of the thin-walled metal sleeve 26 of the fixing roller 12 is preferably 10 to 100 μm.

In the fixing roller 12, a porous material layer 22 of an elastic layer having a high heat insulating effect is formed inside, and a thin-walled metal sleeve 26 having a thickness of 10 to 100 μm is formed outside it. In this way, the fixing roller 12 can be heated to a given fixing temperature by the external heating member 34 to obtain a shortened heating period. This eliminates the need to heat the surface of the fixing roller 12 in the conventional manner even when the image forming apparatus is not in operation, thereby greatly reducing power loss.

The elasticity of the interior of the fuser roller allows the center 18 of the smaller diameter nip roller 12 to flex, thereby eliminating unevenness or pinching of the nip area N in the longitudinal direction. The width is equalized so that a correspondingly uniform load is applied to the transported object and thus prevents problems with the transported object, such as bending it.

In addition, the elastic fixing roller 12 can facilitate increasing the nip width to allow a higher printing speed of the image forming apparatus.

Although the halogen heater 34 is used as an external heating device in the above embodiment for heating the surface of the fixing roller 12 from the outside, the heating device of the present invention is not limited to the halogen heater 34, but electromagnetic induction heating technology may be used. to heat the fixing device 12 . In other words, the thin-walled metal sleeve 26 may be heated by applying heat to it from the outside, or may also be designed to generate heat itself.

As an example of an external heating device, an electromagnetic induction heater 40 using electromagnetic induction heating technology will be described below with reference to FIGS. 11 and 12 .

As shown in FIG. 11 , the electromagnetic induction heater 40 acts as a means to electromagnetically induce heat the thin-walled metal sleeve 26 formed in the fixing roller 12 in the heating zone Z. As shown in FIG. In this example, the electromagnetic induction heater 40 is formed in an arc so as to extend along approximately half of the circumference of the fixing roller 12 . In particular, as shown in FIG. 12 , in different cross-sectional directions, the electromagnetic induction heater 40 includes a non-magnetic base 42 , wherein the base is along the outer peripheral surface of the fixing roll 12 in substantially half of the circumferential direction of the fixing roll 12 . Extending, the heater 40 further includes a magnetic core 44 made of, for example, iron located in the central region of a recessed portion formed in the surface of the base 42 opposite to the fixing roller, and wound around the magnetic core 44, suitable for fixing An exciting coil 46 that generates a variable magnetic field H in the radial direction of the roller 12 . The electromagnetic induction heater 40 is designed to generate a variable magnetic field H by energizing the excitation coil 46 based on a power source (not shown) in a manner of penetrating the width direction of the thin-walled metal sleeve 26 of the fixing roller 12, and An eddy current Ic is generated inside the metal sleeve 26 to induce self-heating of the thin-walled metal sleeve 26 .

Compared with the halogen heater 34, as shown in this modified embodiment, the electromagnetic induction heater 40 used as the external heating means can further rapidly (exponentially) heat the thin-walled metal sleeve of the fixing roller 12 26 , thereby heating the unfixed toner on the unfixed sheet in the nip area between the fixing roller 12 and the squeeze roller 14 .

(manufacturing device 50)

Referring to FIG. 6, a manufacturing device 50 for performing a method of manufacturing the above fixing device will be systematically explained.

This manufacturing apparatus 50 is designed to reduce the outer diameter of the porous material layer 22 of the fixing roller 12 by pressure treatment, then apply an adhesive to the outer peripheral surface of the porous material layer 22 having the reduced outer diameter, and then perform After the adhesive application process, the porous material layer 22 is inserted into the thin walled metal sleeve 26 with a tight fit.

In particular, the manufacturing apparatus 50 has a pressurized container 52 for sequentially performing all the above operations in a pressurized environment. This pressurized container 52 is fluidly connected with a pressure supply mechanism 54 (such as a compressor), and according to the actuation of the pressure supply mechanism 54, the inner space of the pressurized container 52 can have a high pressure environment, such as a high pressure environment of 5 MPa.

In the pressurized container 52, the manufacturing device 50 includes a support 65 for supporting the thin-walled metal sleeve 26 in an upright state, a supporting mechanism 58 for supporting the porous body X, and an adhesive applying device 60, wherein The porous body X includes a center 14 and a layer of porous material 22 positioned around the center 14. The support mechanism 58 is in a coaxial relationship with the thin-walled metal sleeve 26 supported by the support 56. It maintains the coaxial relationship while maintaining the coaxial relationship. The porous body X is moved, and the adhesive applying device 60 is used to uniformly apply adhesive to the outer peripheral surface of the porous material layer 22 of the porous body X supported by the supporting mechanism 58 .

The support mechanism 58 includes a pair of support shafts 62, 64 up and down, which coaxially pass through the support 56 and the thin-walled metal sleeve 26 supported by the support 56, so that the porous material layer 22 can be supported by the support shafts 62, 64 coaxially. ground support. The support shafts 62, 63 are designed to be integrally driven and moved by a movement mechanism (not shown) in such a manner that they are additionally moved in directions spaced apart from each other.

The process of the manufacturing method for manufacturing the above-mentioned fixing roller 12 using the above-mentioned manufacturing apparatus will be described in detail below.

First, the center 16 is placed in the cavity of the injection molding apparatus. In a state where the mold is closed, an emulsifier (for example, the emulsifier obtained in Example 1) as a raw material of the porous material is exhausted in a vacuum decompression device to exhaust mixed air therefrom. Then, the emulsifier is injected into the chamber and allowed to solidify under the same conditions as described in FIG. 1 . Through the above process, a porous body X including a center 16 and a silicon elastomer porous material layer 22 located around the outer peripheral surface of the center 16 and having at least a plurality of closed cells is produced. After opening the mold and taking the porous body X out of the injection molding device, the porous body X is fixed to a grinding device (not shown) to grind the outer peripheral surface of the porous body X so that the porous material layer 22 has A given diameter, eg said outer diameter of 30.5 mm, is equal to or greater than the inner diameter of the thin-walled metal sleeve 26 of 30.0 mm.

Then, the pressurized container 52 is opened to clamp the porous body X between the pair of upper and lower support shafts 62, 64 of the support mechanism 58, and the thin-walled metal sleeve 26 is supported on the support 56 in an upright posture. .

Then, the pressurized container 52 is closed, and the pressure supply device 54 is activated to pressurize the porous body X contained in the pressurized container 52, thereby allowing the outer diameter of the porous material layer 22 to be smaller than the outer diameter of the thin-walled metal sleeve 26 .

Then, as shown in FIG. 7, the adhesive applying device 60 is activated. In addition, starting a motion mechanism (not shown) moves the upper and lower support shafts downward, and applies the adhesive to either one of the outer peripheral surface of the porous body X and the inner peripheral surface of the thin-walled metal sleeve 26, and in this embodiment In the example, specifically, it is applied to the outer peripheral surface of the porous body X to form the adhesive layer 24 .

Then, in the pressurized container 52, the moving mechanism is continuously operated to move the upper and lower support shafts downward, and the porous body X supported therebetween is inserted into the thin-walled metal sleeve 26 to form the sleeve body as shown in FIG. 8 Y.

Then, after the pressurized state is released and the pressurized container 52 is opened to the atmosphere, the sleeve body Y formed in the pressurized container 52 is taken out in the above manner to promote the expansion of the porous material layer 22 of the porous body X. , so that the outer peripheral surface of the porous material layer 22 is in close contact with the inner peripheral surface of the thin-walled metal sleeve 26 . During this close contact, the expansion of the porous material layer 22 occurs when the pressurized state is released, and the expansion is substantially completed at the same time as the pressurized state is released.

Then, the adhesive cures to bond the porous body X and the thin-walled metal sleeve 26 together. During this bonding, the sleeve body Y was accommodated in a constant temperature bath, and heated at 150° for about 30 minutes to bond them together. It should be understood that the aging treatment may be performed after completion of the bonding process depending on the heating.

The outer peripheral surface of the thin-walled metal sleeve 26 is previously covered with a release layer 28 made of PFA which is a fluororesin. Thus, when the bonding process is completed, the fixing roller 12 can be obtained as a product.

It should be understood that the fixing roller of the present invention is not limited to the above specific embodiments and examples, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Various examples of improvements to the fixing device in the above embodiments will be described below with reference to the drawings. In the following description, the same elements or parts as those of the previous embodiment are given the same reference numerals, and the description thereof will be omitted.

(Structure of the fixing roller)

For example, although the release layer 28 is formed directly on the outer peripheral surface of the thin-walled metal sleeve 26 in the foregoing embodiments, the fixing roller 12 is not limited to this structure. For example, as shown in FIG. 9, before it is arranged in the injection molding device, the release layer 28 is not formed on the outer peripheral surface of the thin-walled metal sleeve 26, but only the elastic layer 48, such as silicon rubber, is formed on the thin-walled metal sleeve 26. on the outer peripheral surface of the metal sleeve 26 . Then, after the thin-walled metal sleeve 26 and the porous material layer 22 are integrated, the release layer 28 is formed on the outer peripheral surface of the thin-walled metal sleeve 26 . That is, the release layer 28 is not an essential component for the present invention, but it can be fixed or formed at any time.

(Application of fixing roller)

While the fixing roller of the present invention is applied to the heat fixing roller of the above-mentioned embodiment, the present invention is not limited to application to the heat fixing roller, but as shown in FIG. middle.

Furthermore, although the manufacturing method in the above-described embodiment includes reducing the outer diameter of the porous body X by a method of pressurization, the outer diameter of the porous body X may be reduced by a method of pressurization. What is important is that when the porous body X is inserted into the thin-walled metal sleeve 26 to form the sleeve body Y, the porous body X is allowed to have a pre-inserted outer diameter set to be smaller than the thin-walled metal sleeve 26 The inner diameter of the sleeve 26 is also allowed to have an outer diameter substantially equal to or slightly larger than the inner diameter of the thin-walled metal sleeve 26 after insertion. As such, any suitable technique to achieve this change may be employed. For example, a technique of reducing the diameter of the porous body X by pressurization or decompression, which uses the pressure applied to the porous body X as a parameter, or a method of increasing the thickness of the thin-walled metal sleeve 26 by heating can be used. The diameter of the porous body X or the technique of reducing the diameter of the porous body X by cooling, which takes heat as a parameter.

In the above embodiment, when the porous body X is inserted into the thin-walled metal sleeve 26, the porous body X includes "the center 16 and a silicon elastomer porous material located around the outer peripheral surface of the center 16 and having at least a plurality of closed cells." Layer 22". However, the present invention is not limited to this operation. For example, a porous body X consisting only of a hollow silicon elastomer porous material layer 22 without a center 16 can also be inserted into a thin-walled metal sleeve 26, and then the center 16 can be inserted into the inserted thin-walled metal sleeve. 26 in the central hole of the silicon elastomer porous material layer 22. In this case, even if the outer diameter of the silicon elastomer porous material layer 22 is set substantially equal to or slightly larger than the inner diameter of the thin-walled metal sleeve 26, the hollow silicon elastomer porous material layer 22 without the center 16 can be easily and be reliably inserted into the thin-walled metal sleeve 26 , or the sleeve body Y is easily and reliably composed of the porous body X and the thin-walled metal sleeve 26 .

In the foregoing manufacturing process, in order to form the porous body X, the center 16 is set in an injection molding apparatus, and an emulsifier which is a raw material of the porous material is injected onto the outer peripheral surface of the center 16 so that the porous material layer 22 is formed in the injection molding apparatus. The device covers the outer peripheral surface of the center 16 . However, the present invention is not limited to this operation. For example, a cylindrical porous body formed with a center insertion hole may be prepared, and then the center 16 may be inserted into the cylindrical porous body. That is, any suitable sequence for forming the layer of porous material 22 around the outer peripheral surface of the center 16 may be employed.

In the above-described embodiment, the process of applying the adhesive to the outer peripheral surface of the porous material layer 22 is performed under the pressure environment in the pressurized container 52, or the reduced time for applying the adhesive to the porous material layer 22 is completed. on the peripheral surface. The present invention is not limited to this operation. For example, the adhesive may be applied to the outer peripheral surface of the porous material layer 22 under atmospheric pressure, or the adhesive may be applied to the outer peripheral surface of the porous material layer 22 before the diameter reducing process to obtain the same effect.

Although the release layer 28 in the aforementioned manufacturing method is formed by the silicone rubber layer 26b as an elastic layer, the present invention is not limited to this operation, but the release layer 28 may be directly formed on the sleeve body 26a of the thin-walled metal sleeve 26 on the outer peripheral surface.

Furthermore, in the above-described embodiment, although the PFA tube was tightly fitted to cover the silicone rubber layer 26b during the formation of the fluororesin release layer 28, the present invention is not limited to this operation. For example, PFA may be coated on the outer peripheral surface of the thin-walled metal sleeve 26 . It should be understood that the adhesive may be applied directly on the outer peripheral surface of the silicone rubber layer 26 b formed on the outer peripheral surface of the thin-walled metal sleeve 26 .

Furthermore, in the foregoing embodiments, although the thin-walled metal sleeve 26 is adhered to the outer peripheral surface of the porous material layer 22 through the adhesive layer 24, the present invention is not limited to this arrangement. For example, as long as the thin-walled metal sleeve 26 and the layer of porous material 22 are in frictional engagement with each other and the center 16 is rotatably driven from the outside, the thin-walled metal sleeve 26 can operate according to the layer of porous material located in such a structure. 22, or as long as the porous material layer 22 (or center 16) can rotate with the thin-walled metal sleeve 26 in a structure in which the thin-walled metal sleeve 26 can be rotationally driven from the outside, then it does not The adhesive layer 24 is not required.

Claims (15)

1. fixing roller, it comprises:

The center;

Porous material layer comprises the closed cell formula silicone elastomer that adopts the emulsifying agent complex to be prepared from, described this porosint be positioned at described center outer surface around; With

Cover the thin-walled metal sleeve on the outer surface of described porous material layer.

2. fixing roller as claimed in claim 1, the unit ratio that the described silicone elastomer that wherein forms described porosint has a plurality of sealings accounts for 60% or more unit, and 50% or the more unit that wherein account for whole number of unit have 50 μ m or littler diameter respectively.

3. fixing roller as claimed in claim 2 wherein accounts for 50% or the formula (A) below more each unit satisfies of whole number of unit:

0≤(m-n)/m≤0.5 ----(A)

The maximum gauge of m representative unit wherein, the minimum diameter of n representative unit.

4. fixing roller as claimed in claim 3 wherein accounts for 50% or the formula (B) below more each unit satisfies of whole number of unit:

0≤(m-n)/n≤0.5 ----(B)

The maximum gauge of m representative unit wherein, the minimum diameter of n representative unit.

5. fixing roller as claimed in claim 4, the averaging unit diameter of wherein said silicone elastomer are 30 μ m or littler.

6. fixing roller as claimed in claim 2, the ratio of the closed cell of wherein said silicone elastomer are 80% or bigger.

7. fixing roller as claimed in claim 2, the diameter of wherein said each unit at 0.1 μ m between the 70 μ m.

8. fixing roller as claimed in claim 1, wherein said porous material layer adopt water in oil emulsifying agent complex preparation, and this complex comprises the curable fluid silicone rubber material with the formation silicone elastomer, has the silicone oil material and the water of surface active function.

9. fixing roller as claimed in claim 1, it can comprise the releasing layer that is formed on around the described thin-walled metal sleeve outer surface.

10. fixing roller as claimed in claim 9, it comprises the elastic layer between described releasing layer and described thin-walled metal sleeve.

11. fixing roller as claimed in claim 1, it comprises the elastic layer that is formed on the described thin-walled metal sleeve outer surface.

12. fixing roller as claimed in claim 1, it comprises the releasing layer that is formed on the described elastic layer outer surface.

13. as claim 9 or 12 described fixing rollers, wherein said elastic layer can be made by fluororesin.

14. fixing roller as claimed in claim 13, wherein said fluororesin is coated on the outer surface of described elastic layer.

15. fixing roller as claimed in claim 13, wherein said fluororesin can form tubulose, and covers on the outer surface of described elastic layer.

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