JPH1165340A - Fixing roller and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A fixing roller and a fixing roller having a phase-change heating layer in which particles of a phase-change heating material that generates thermal energy during a phase transition from an amorphous phase to a crystalline phase are dispersed in a binder. In addition, the present invention provides a fixing roller having an excellent heating promoting effect and a method for manufacturing a fixing roller having a good phase-change heat generating layer. SOLUTION: The present invention provides a fixing device having a phase change heat generating layer 5 in which particles 3 of a phase change heat generating material that generates heat energy at the time of a phase transition from an amorphous phase to a crystalline phase are dispersed in a binder 4. Roller. The particles 3 are aggregates formed by reduction in a binder solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing roller used in a fixing device such as a copying machine, a printer, a facsimile, and the like, and a method of manufacturing the fixing roller.

[0002]

2. Description of the Related Art Generally, in an electrophotographic copying machine, a printer, a facsimile, etc., fixing of a developed image
A fixing device including a fixing roller and a pressure roller is used. In this fixing device, printing paper on which toner has been transferred and developed is inserted between rollers between the fixing roller and the pressure roller. As a result, the toner that forms the image is heated and melted (softened), and is fused and fixed on the printing paper.

As a fixing roller of this kind, the applicant of the present application has provided a phase-change heating layer around the outer periphery of a hollow cylindrical core with a phase-change heating material capable of phase transition between an amorphous phase and a crystalline phase. There has been proposed a fixing roller having a configuration in which the phase change heat generating layer is covered with a protective layer (for example, see Japanese Patent Application Laid-Open No. Hei 7-140823). According to this fixing roller, the temperature of the outer peripheral surface of the fixing roller reaches a temperature (predetermined temperature) required for fixing by using a temperature rise by heating from the main heat source.
In the phase transition heating layer, heat energy (crystallization energy) is generated by a phase transition from an amorphous phase to a crystalline phase. Thereby, the temperature rise of the outer peripheral surface of the fixing roller is promoted more than the temperature rise of only the main heat source. The use of this fixing roller is expected to reduce the warm-up time and save power.

From such a viewpoint, the applicant has proposed that a material having a temperature higher than the softening temperature of the toner and having a melting point as low as possible is preferable in order to satisfy the function of fixing the toner and save energy. Material as Se
And chalcogenide alloys, PE
It has also been shown that organic polymers such as T and PBT, and low molecular weight organic substances such as bisphenol A derivatives are practical.

[0005]

However, in order to repeatedly use such a fixing device, the phase-change exothermic material must be melted and crystallized in order from an amorphous phase to a crystalline phase and from a crystalline phase to an amorphous phase. Will be repeated. However, when the melting point is exceeded, the phase-change heat-generating material formed in a thin layer on the roller core is agglomerated due to surface energy, causing irregularities in the roller surface shape, which is unsuitable for use as a roller. May be. Therefore, it is desirable that these phase-change exothermic materials be coated and dispersed with a binder so that the phase-change exothermic materials are not mutually aggregated by melting, so that the phase-change exothermic materials are isolated from each other. Further, it is desirable that the phase change heat generating layer having such a configuration has good thermal conductivity.

[0006] Therefore, the applicant of the present invention has proposed to increase the thermal conductivity by mixing a high-conductivity material having a higher thermal conductivity than the crystal phase of the heat-generating material with the phase-change heat-generating material or dispersing it in a binder. It has been proposed (for example, see Japanese Patent Application Laid-Open No. 9-342297). The binder used must be thermally stable at a temperature equal to or higher than the melting point of the phase change exothermic material. Examples of such a binder include a fluorine resin, a polyimide resin, and an epoxy resin. Among these,
Polyimide resin has good chemical resistance and is a suitable material for these binders.However, the method of dispersing the pulverized particles in the binder is extremely limited, and good phase transition heat generation is achieved. It was very difficult to obtain a layer (film).

[0007] From such a viewpoint, the present applicant has proposed a method of impregnating a phase-change exothermic substance into a porous fluororesin PTFE by vapor deposition (for example, Japanese Patent Application No. Hei.
144129). In addition, a method has been proposed in which a porous fluororesin-coated support is immersed in a solution containing a phase-change exothermic material to precipitate the phase-change exothermic material.

[0008] Further, a method of dispersing a raw material which becomes a phase-change exothermic material when decomposed into a coating liquid, applying the applied material, and decomposing the raw material by heating to deposit a phase-change exothermic material was also studied. However, when the fixing roller according to this method is used, there is a problem in that the amount of heat generated by the bending is dissipated before reaching the fixing temperature and the efficiency is rather lowered. This is presumed to be due to the particle diameter of the particles precipitated by this method being too fine, which is considered to lower the crystallization heat temperature of the phase change heat generating material.

On the other hand, the present applicant can expand the crystallization heating temperature range of the phase change exothermic material by mechanically pulverizing the phase change exothermic material to, for example, 0.5 mm or less,
The fixing roller using the pulverized phase change heat-generating material,
It has been found that the heating is promoted from a low temperature, and as a result, the heating promoting effect is excellent (for example, see Japanese Patent Application No. 9-1997).
No. 8607).

However, the method of dispersing the pulverized phase-change exothermic material in the binder is limited, and it has been difficult to obtain a good phase-change exothermic layer.

The present invention has been made in consideration of the above circumstances, and disperses particles of a phase-change exothermic material that generates thermal energy during a phase transition from an amorphous phase to a crystalline phase in a binder. In a fixing roller having a phase change heat generation layer, a crystallization heat generation temperature range can be expanded, thereby providing a fixing roller having an excellent heating promoting effect and a method of manufacturing a fixing roller having a good phase change heat generation layer. Is to do.

[0012]

In order to achieve the above object, the invention of claim 1 combines particles of a phase-change exothermic material that generates thermal energy during a phase transition from an amorphous phase to a crystalline phase. In a fixing roller having a phase-change heating layer dispersed in a binder, the particles are aggregates formed by reduction in a binder solution.

Since the phase-change heating layer uses a phase-change heating material that generates heat energy at the time of a phase transition from an amorphous phase to a crystalline phase, heating at the time of rising is promoted. In addition, since the particles of the phase-change exothermic material are dispersed in the binder, the particles do not aggregate even if the cycle of melting and crystallization of the particles is repeated. Further, since the particles are obtained by reduction in a binder solution, the particles are well dispersed in the binder. As a result, the particles are well bound by the binder, so that a good phase-change heating layer (film) can be obtained. Further, since these particles are agglomerates, they have a particle size (particle size) distribution, so that a width is generated in a crystallization heat generation temperature region, and a good rise in the surface temperature of the fixing roller can be obtained.

According to a second aspect of the present invention, in the method of manufacturing a fixing roller according to the first aspect, in the step of forming the phase-change heating layer, a raw material that becomes a phase-change heating material by reduction is combined with a reducing agent. A mixing step of mixing in the adhesive solution, a particle precipitation step of causing the mixture to react to precipitate agglomerates of the phase change exothermic material into particles, and applying the mixture to at least a part of the surface of the roller or the inside of the roller. And a coating step.

When a raw material that becomes a phase-change exothermic material by reduction and a reducing agent are mixed in a binder solution, the raw material is reduced to become a phase-change exothermic material, and agglomerated in the binder solution. A dispersion is formed in which the phase change exothermic material is dispersed in the binder. This dispersion is applied to the surface of the roller or at least a part of the inside of the roller at an appropriate stage to form a phase change heating layer. As a result, a phase change heat generating layer in which particles of the phase change heat generating material are dispersed in the binder is formed. In this phase transition heating layer, the particles of the phase transition heating material are formed by being applied in a dispersed state.
The phase change heat generating material is dispersed inside the coating layer. Further, since these particles are agglomerates, they have a particle size (particle size) distribution, so that a width is generated in a crystallization heat generation temperature region, and a good rise in the surface temperature of the fixing roller can be obtained.

The invention according to claim 3 is the method according to claim 2, wherein the raw material is selenium dioxide.

Selenium dioxide as a raw material is dispersed in a binder solution, and this selenium dioxide is reduced in the binder solution to precipitate selenium in the form of particles in the form of agglomerates. These selenium particles can be dispersed by stirring and mixing to form a phase change heat generating layer by a coating method such as a wet method.
This selenium is also a good phase change exothermic material.

The invention according to claim 4 is the method according to claim 3, wherein the reducing agent is at least one selected from handloquinones and hydrazines.

[0019] By using these reducing agents, selenium becomes a good precipitated aggregate and is precipitated as particles. Since the aggregates are easily dispersed in the binder, the phase change heat generating layer can be easily formed by a coating method such as a wet method.

According to a fifth aspect of the present invention, there is provided the method of manufacturing a fixing roller according to any one of the second to fourth aspects, wherein the binder solution contains a polyimide precursor.

Polyimide is a good heat-resistant binder, and the use of a precursor facilitates solution application. Further, since the particles of the phase-change exothermic material are covered with the strong polyimide film, the phase-change exothermic material does not aggregate even if the cycle of melting and crystallization of the phase-change exothermic material is repeated.

According to a sixth aspect of the present invention, there is provided a phase change heat generating layer made of polyimide in which particles of a phase change heat generating material that generates heat energy during a phase transition from an amorphous phase to a crystalline phase are dispersed in polyimide. In a method of manufacturing a fixing roller having a surface protective layer formed on a substrate, a polyimide precursor dispersion containing particles of a phase-change exothermic material formed by reduction in a polyimide precursor solution is applied to a support. After forming the phase change heat generating layer, the phase change heat generating layer is pre-heated at a temperature equal to or lower than the melting point of the phase change heat generating material, and then, after a surface protective layer is provided, the phase change heat generating layer is heated to imidize. A method for manufacturing a fixing roller.

Since the particles of the phase change exothermic material are covered with a strong polyimide film, the melting of the phase change exothermic material,
Aggregation of the phase change exothermic material does not occur even if the crystallization cycle is repeated.

According to this structure, the use of the polyimide precursor makes it easy to disperse the particles of the phase-change exothermic material. In addition, since the layer can be formed by a wet coating method, the phase-change exothermic layer can be formed in an optional manner. It becomes easy to process it into a form.
As a result, a good phase transition heating layer in which the particles of the phase transition heating material are dispersed is formed.

Further, since the polyimide precursor can be imidized even at a temperature lower than the melting point of the phase-change exothermic material, the phase-change exothermic layer can be fixed before the phase-change exothermic material is melted by preheating. By providing the protective layer on the surface, a fixing roller having the protective layer on the surface can be easily manufactured.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fixing roller according to the present invention will be described below with reference to the drawings.

The fixing roller of the present invention discharges the energy stored in the material in the form of heat by utilizing the temperature rise caused by heating from the main heat source, so that the surface of the fixing roller becomes faster than the temperature rise of the main heat source alone. It applies the principle of raising the temperature, and is used as a fixing roller of a heat fixing device.

The fixing roller 1 has, for example, a hollow cylindrical cored bar 2 as shown in FIG. As the material of the metal core 2, for example, aluminum, its alloy, stainless steel, or the like is used. A phase change heating layer 5 is formed on the outer periphery of the cored bar 2. The phase change heat generating layer 5 is formed by dispersing particles 3 composed of aggregates formed by reduction in a binder solution in a binder 4. An example of the production of the aggregate is shown in FIG. 2 as a whole example of the production process of the fixing roller, and the details will be described later.

A protective layer 6 is formed on the outer periphery of the phase change heating layer 5. The protective layer 6 covers and seals the phase change heat generating layer 5 to prevent the particles 3 from flowing out in a molten state, and has releasability to prevent adhesion to toner and the like. An adhesive layer, a current-carrying layer, an insulating layer, and the like may be added to the fixing roller 1 as necessary.

The fixing roller 1 is provided with a main heat source for raising the temperature of the outer periphery of the fixing roller 1 to the toner fixing temperature and heating and melting the crystallized phase change heating layer 5. In this example, a hollow portion 7 inside the cored bar 2 is used.
, A main heat source (not shown) is provided. Examples of the main heat source include a heater such as a halogen lamp, an infrared lamp, and a nichrome wire. It may be an electric heating layer that generates heat when energized.

The phase-change exothermic material used in the present invention is:
It is a material that generates heat with phase transition. Such materials are
Generally, a so-called amorphizable region, which becomes amorphous by quenching from a molten state, and crystallizes (forms a crystalline phase) when the temperature of a substance in the amorphous state (amorphous phase) is raised. It is a substance with.

These phase-change exothermic materials generate heat during the phase transition from the amorphous phase to the crystalline phase. Since the crystallization temperature is a temperature specific to the substance, the crystallization start temperature and the crystallization start temperature are It depends on the phase-change exothermic material used. The crystallization temperature is the temperature at which the amorphous phase, which is metastable in terms of energy, changes to a more stable crystal phase, and is between the melting point determined by the substance and the glass transition point. This melting point is an important property for re-amorphizing a substance once heated and reinitializing the substance. The melting point is higher than the fixing temperature at which the toner is softened and fused, and the temperature is as low as possible from the viewpoint of energy saving. Is desirable.

One example of the phase-change exothermic material having such performance is described in detail in, for example, JP-A-9-342297. Those having an amorphizable region selected from Groups III to VI of the periodic table are exemplified as preferred examples, and these may be used alone or in a multi-component system. Among these, chalcogens mainly containing chalcogens (Se, Te, S) and chalcogenide compounds, especially amorphous materials mainly composed of Se rapidly crystallize and generate heat.
In addition, since the heat generated during crystallization is large, the material is suitable.

In the present invention, these phase-change exothermic materials are used in the oxidized state as raw materials. A raw material in an oxidized state, that is, a raw material that becomes a phase-change exothermic material by reduction (hereinafter, simply referred to as a raw material) is mixed with a reducing agent in a state of being dispersed or dissolved in a binder solution. You may mix both by adding the binder which melt | dissolved the raw material in the solution of the reducing agent. This raw material is reduced in the binder solution to become a phase change exothermic material.
At the same time, the phase-change exothermic material precipitates as agglomerates in the form of particles. This reduction reaction is promoted by heating if necessary. As will be described later, this heating can be performed in a drying step in the process of forming the phase change heating layer.

Raw materials having such properties include:
Dissolved or dispersed in the binder solution, and the composition of the material that precipitates as the phase transition exothermic material as a reduced product generated by the reaction becomes insoluble in the binder solution, It is appropriately set in consideration of the raw material, the type of the binder, the solvent thereof, the type of the reducing agent, and the like.

Since the binder is provided in a state of being dissolved or dispersed in water or an organic solvent, a raw material which is dissolved or finely dispersed in the water or the organic solvent is selected.
As a raw material having such properties, an inorganic selenium compound is exemplified as a suitable material. This inorganic selenium compound is soluble in many organic solvents, and separates and precipitates selenium by reduction. The obtained selenium is rapidly crystallized and generates heat, and is a suitable phase transition heat generating material having a large heat generation energy during crystallization.

Such selenium compounds include selenium dioxide, selenous acid, selenium halide and the like.
The selenium dioxide may be such that aggregated particles are precipitated by a combination with a reducing agent described later. In addition, it is easily available in high purity.

The particles of the phase change exothermic material used in the present invention are formed by reducing these materials in a binder solution. Here, what is formed by reduction means that the above-mentioned raw materials are mixed with a reducing agent and the like, and a reduction reaction is allowed to proceed, so that the generated phase-transition exothermic material becomes fine particles in the binder solution. Means deposited. These fine particles become agglomerates and have a distribution in particle diameter. Therefore, a wide crystallization temperature range is obtained as will be apparent from the examples described later.
Use of the particles having such a wide crystallization region can promote the heating of the fixing roller.

As the reducing agent to be used, any reducing agent may be used as long as the use of the obtained fixing roller is not hindered. As the reducing agent used in the present invention, for example, phenols, hydroquinones, amines, diamines,
Hydrazines, aldehydes and the like can be mentioned. Trimethylhydroquinone, tetramethylhydroquinone, alkylhandloquinones such as 2,5-di-tert-butylhydroquinone, chlorohydroquinone, hydroquinones such as halogenated hydroquinones such as bromohydroquinone, hydrazine, salicyloylhydrazide, acetylphenylhydrazine and the like. By adding hydrazine to a binder solution in which the raw material is dispersed or dissolved, the hydrazine can easily and efficiently reduce the raw material to precipitate a phase-change exothermic material. These reducing agents may be used alone or as a mixture.

On the other hand, the binder 4 according to the present invention means that even if the particles 3 of the phase-change exothermic material are melted for amorphization, the particles 3 retain the particle form by the action of the binder 4. It is a possible shape-retaining material. For this purpose, it is desirable that the binder 4 is a material that does not melt or decompose in a high temperature state where the particles 3 are melted. Examples of such a material include a crosslinked polymer and a high melting point polymer, and specific examples thereof include a fluororesin, a polyimide resin, and an epoxy resin.

Among these, polyimide is excellent in heat resistance and chemical resistance and is a suitable material for the binder, but the method of dispersing the phase change exothermic material in the binder is extremely limited. Therefore, it is generally very difficult to obtain a good phase change heating layer. In the present invention, it has been found that by using a precursor that has not been imidized, the phase-change exothermic material can be dispersed in the binder.

Many polyimides are usually produced by a special vapor deposition polymerization method, but when polymerized from an imide monomer, they are polymerized in a solvent and pass through an intermediate provided as a solution. This intermediate is called a polyimide precursor because it generates water by heating to complete the imidization reaction and produce polyimide. When the particles of the phase-change exothermic material are dispersed in the solution of the polyimide precursor and the imidization is completed while dehydrating by heating or the like, a strong polyimide film is formed. In this film, even if the phase-change heat generation material is melted to amorphize the internal phase-change heat generation material in a state where the particles are coated, the coating film may be melted or decomposed. By maintaining the morphology of the particles, the initial morphology of the particles can be maintained. This polyimide precursor can form a good dispersion film by utilizing this property.

Such a polyimide precursor is commercially available as a solution of a polyimide precursor such as a wholly aromatic polyamic acid or polyamic acid for use as a heat-resistant insulating varnish. A wholly aromatic polyimide varnish is preferably used because it has particularly excellent binding properties and heat resistance. Such a precursor can be diluted, so that it is easy to adjust the viscosity to be appropriate for dispersing the phase change exothermic material described later. Thereby, the particles of the phase-change exothermic material can be easily dispersed, and a dispersion coating liquid in which the phase-change exothermic material is dispersed can be obtained. As these solvents, N-methyl-2-pyrrolidone, dimethylacetamide, aromatic hydrocarbons and the like are used.

The dispersion in which agglomerates of the phase-change exothermic material are precipitated in such a binder is subjected to a known method such as spraying, dipping, or spin-on, for example, to a thickness of 0.1.
The phase-change heat-generating layer 5 can be obtained by being applied to an arbitrary position such as the surface or inside of a core metal forming a roller as a layer of about mm and being dried. As a result, the phase-change exothermic layer 5 in which the particles 3 of the phase-change exothermic material are firmly sealed inside by the coating film 4 of the adhesive and the form is protected is obtained.

Even when the binder, the raw material and the reducing agent are mixed and the raw material has not been sufficiently reduced, the coating can be performed by the above-mentioned wet coating method. In this case, in the drying step of the obtained layer, the phase change material precipitates as agglomerates.

When a polyimide precursor is used as a binder, the polyimide can be formed by imide ring closure by heat treatment after molding by a coating method. Further, this coating film has a temperature equal to or lower than the melting point of the phase change heat generating material, for example, 120 ° C.
By preheating at a temperature of about ° C, a relatively stable coating film can be obtained. This preheating can also serve as a drying step for removing the solvent in the binder. For example, 60 ° C
Drying at a low temperature of about 100 ° C. and drying at a high temperature of about 100 ° C. can also be used. After this preliminary heating, any processing such as provision of a protective layer can be performed. Thus, the phase-change heating layer 5 can be fixed before the particles 3 of the phase-change heating material melt.

Further, since the imidization reaction is a dehydration reaction, it is necessary to remove generated gas. This can be achieved by reducing the pressure during heating. In order to complete the imidization reaction after providing the layer such as the protective layer 6, it is necessary to open one end to reduce the pressure. Thereby, it is possible to obtain the phase change heat generating layer 5 without moisture remaining in the phase change heat generating layer 5 and without any bubbles inside. Further, if the open end is sealed while reducing the pressure inside, a fixing roller having no bubbles inside can be obtained. Such a fixing roller is less likely to deform due to air bubbles or the like due to heating during use of the roller during molding.

Other layers such as the phase change heat generating layer 5 and the protective layer 6 may further contain other additives as necessary. For example, by blending a material having good thermal conductivity (good thermal conductive material) such as carbon black into the binder, the heat transfer rate of the phase change heat generating layer is increased, and the surface temperature of the roller is increased to a desired temperature. Can promote that.

Hereinafter, the present invention will be described in detail with reference to examples.

(Reference Example 1) (Mechanical grinding of sample) High-purity Se (purity: 99.999%) pellets prepared by the shot method in molten water were crushed by a crusher, and the obtained powder was 0.5 mm or more. Lump, 0.2
Classify into powder of 0.5 mm and fine powder of less than 0.1 mm.
Each sample was subjected to thermal analysis DTA under a condition of a heating rate of 10 ° C./min, and measured data are shown in FIGS.

As shown in FIG. 3, a lump of 0.5 mm or more has a crystallization exothermic peak Pc having a sharp peak at 140 ° C. On the other hand, as shown in FIGS. 4 and 5, in the case of a mechanically pulverized sample having a particle size of less than 0.5 mm, a relatively large heat generation occurs at 110 ° C. on the low temperature side in addition to the peak at 140 ° C. Exothermic peak P
c can be recognized. From this, it is understood that this mechanically pulverized sample is a material having a wide range of heat generation region from the low temperature side to the high temperature side, and the crystallization start temperature can be controlled by a simple structure of controlling the particle size. It is understood that it is possible.

(Preparation of Fixing Roller) A material having a particle diameter of less than 0.2 mm was dispersed in an epoxy adhesive (thermally conductive form holding material) in which a thermally conductive dispersant was dispersed to obtain a coating liquid.
Using this coating liquid, a phase change layer having a thickness of 0.5 mm was formed by uniformly coating and drying on an Al core having an outer diameter of 20 mm. Thereafter, the phase-change layer was covered and sealed with a heat-shrinkable tube of a fluororesin PFA as a protective layer to prepare a fixing roller of roller number A.

A similar pulverized material of less than 0.2 mm is dispersed in a thermoplastic polyimide-based adhesive in which a thermally conductive dispersant is dispersed, and is dried and ground to obtain a powder coated with a thermally conductive form holding material. I got a body. Then, this powder was prepared with an outer diameter of 20 mm
A 0.5 mm thick phase change layer 3 was formed by uniformly applying electrostatic coating on the Al cored bar. Thereafter, the resultant was covered and sealed with a heat-shrinkable tube made of a fluororesin PFA as a protective layer to prepare a fixing roller of roller number A '.

Next, the vapor deposition source charged with the derivative of diphenyl isophthalate (crystallization peak temperature 70 ° C., melting point 210 ° C.) was heated by energization, and vacuum-deposited on an Al core metal having an outer diameter of 20 mm to form a film. A phase change layer having a thickness of 0.5 mm was formed. After that, a protective layer was formed in the same manner as described above to prepare a fixing roller of roller number B.

Using the same Se material, a 0.5 mm thick phase change layer was formed on the outer periphery of a core metal having an outer diameter of 20 mm by vacuum evaporation. Thereafter, a protective layer was formed in the same manner as described above to prepare a fixing roller of roller number C.

Similarly, a derivative of diphenyl isophthalate (a crystallization peak temperature of 70 ° C., melting point of 210 ° C.) and a derivative of tri-pentamer obtained by adding diphenyl carbonate to bisphenol A (Tcp of 100 ° C., melting point of 215 ° C.) Are supplied as separate evaporation sources, the both evaporation sources are energized and heated, and are vacuum-deposited on an Al core having an outer diameter of 20 mm to a thickness of 0.5 mm.
Was formed. Thereafter, a protective layer was formed in the same manner as described above to prepare a fixing roller of roller number D.

The fixing rollers (A to D) were incorporated in a fixing device of an electrophotographic copying machine M210 manufactured by Ricoh, and the temperature rise on the outer peripheral surface of the fixing roller was measured while heating with a heater power of 960 W. In addition, these rollers A to D
Prior to assembling, at least the melting point of each (roller A, A
'And C were heated to 250 ° C, and rollers B and D were heated to 230 ° C), and then rapidly cooled at a cooling rate of 10 ° C or more per minute to make the phase change heating layer an amorphous state. FIG. 6 shows the result.

As is clear from FIG. 6, in the roller B using only the low-temperature-range phase-change exothermic material, the effect of accelerating the temperature rise is recognized at an early stage as the temperature rises. The effect of promoting temperature rise is not obtained.

In the roller C using the high-temperature phase-change exothermic material alone, since the crystallization start temperature is high, the timing at which the effect of promoting the temperature rise is exerted is late, and overheating is observed.

In the roller D using two kinds of phase change heating materials, the temperature rises in two steps.

On the other hand, in the rollers A and A 'using the mechanically pulverized sample, the surface temperature is accelerated from the crystallization start temperature of the lower crystallization temperature, and the surface temperature is increased by the higher crystallization temperature. The temperature is continuously raised in a smooth manner to a predetermined temperature up to the crystallization end temperature. Thus, it is understood that the fixing roller 1 using the mechanically pulverized sample is effective in shortening the warm-up time.

Further, in the rollers A and A ', the fine particles are covered with a heat conductive form retaining material and are protected and separated so as not to contact each other. As a result, even if the particles are repeatedly used, the particles do not become compatible with each other, and a constant particle size can be always maintained. In addition, the heat of the main heat source generated inside can be conducted well.

From the above, it is understood that the heating region can be controlled by controlling the particle size of the phase change heating material. For example, a material with more heat generation in a low temperature range can be obtained by reducing the particle diameter. It is also understood that this sample is effectively used as a material for accelerating the temperature rise in a wide range from a low temperature side to a high temperature side.

(Example 1) 90% of high-purity selenium dioxide SeO2 purified by roasting sludge generated from copper refining
Parts by weight, and a solution concentration of 20 parts by
% (Mixing step). Next, trimethylhydroquinone was added to the obtained mixed liquid to precipitate selenium fine particles (particle deposition step). The fine particles of selenium became aggregates and had a distribution in particle diameter as compared with the fine particles of Comparative Example 1 described later.

The mixture was stirred and sprayed on the surface of a cylindrical support cored bar made of aluminum having an outer diameter of 20 mm in a state where the aggregates were substantially uniformly dispersed (coating step).
Next, the work is dried at 60 ° C. to a thickness of 100 μm.
m was formed.

Thereafter, a heat-shrinkable tube made of fluororesin PFA (perfluoroalkoxy) is put on the phase-change heating layer 5 to seal one end, and the other end is opened, and the pressure is reduced by a rotary pump from the open end. While gradually 300
Heated to degree C. Thereafter, the open end was sealed to form a protective layer 6 covering and sealing the phase change heat generating layer 5.

Then, the work was rapidly cooled at a cooling rate of 10 ° C./min or more to produce a fixing roller of Example 1.

Example 2 A fixing roller of Example 2 was obtained in the same manner as in Example 1 except that salicyloyl hydrazide was used as a reducing agent instead of trimethylhydroquinone.

Example 3 Example 1 was repeated except that hydrazine was used as a reducing agent in place of trimethylhydroquinone.
In the same manner as in Example 1, a fixing roller of Example 3 was obtained.

(Comparative Example 1) Hydrogen sulfide (H2S) gas was blown into the same polyimide precursor solution containing high-purity selenium dioxide SeO2 as in Example 1 to precipitate selenium sulfide fine particles. The fine particles of selenium sulfide were finer than the fine particles of Example 1 and had a uniform particle diameter.

The precipitate was stirred and the particles were substantially uniformly dispersed, and spray-coated on the surface of a cylindrical support cored bar made of aluminum having an outer diameter of 20 mm. Next, the work was dried at 60 ° C., and then heated to 100 ° C. to form the phase change heat generating layer 5.

Thereafter, the protective layer 6 was formed in the same manner as in Example 1, and was quenched to produce a fixing roller of Comparative Example 1.

(Comparative Example 2) A dispersion in which the Se material mechanically pulverized in Reference Example 1 was directly dispersed in a polyimide precursor solution diluted to a solution concentration of 20% was used. This dispersion was stirred to disperse the particles substantially uniformly, and the outer diameter was 20%.
The surface of a cylindrical support core bar made of aluminum having a thickness of 0.2 mm was spray-coated, and then a fixing roller of Comparative Example 2 was produced in the same manner as in Example 1.

The rollers obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were used in an electrophotographic copying machine M2 manufactured by Ricoh Co., Ltd.
The temperature of the roller surface in the actual machine was examined while being heated with a halogen heater power of 960 W installed in a cored bar and installed in a cored bar.

From the comparison between the roller obtained in Comparative Example 1 and the other rollers, it can be seen that the rise time of the roller is shortened by providing the phase change heat generating layer. Further, from the comparison between Examples 1 to 3 and Comparative Examples 1 to 4, all the rollers irradiated with light according to the present invention and having a good conductive material deposited on the surface have reduced rise time and accelerated the rate of temperature rise. It is recognized that it is.

[0076]

As described above, according to the present invention,
The following effects can be expected.

According to the first aspect of the present invention, the crystallization heating temperature range can be widened, thereby providing a fixing roller having an excellent heating promoting effect.

According to the second aspect of the present invention, a phase change heat generating layer in which particles of the phase change heat generating material are dispersed in a binder is formed. In the phase change heat generation layer, particles of the phase change heat generation material are dispersed in an agglomerated state. In addition, the particles are agglomerates, thereby providing a preferable manufacturing method of the fixing roller according to claim 1.

According to the third aspect of the present invention, there is provided a method of manufacturing a fixing roller in which particulate selenium having a large amount of heat generation at the time of phase transition is dispersed in a binder.

According to the fourth aspect of the present invention, there is provided an easy manufacturing method of a fixing roller having a phase change heat generating layer in which good aggregates are dispersed in a binder.

According to the fifth aspect of the present invention, there is provided a fixing roller using polyimide having good heat resistance as a binder.

According to the sixth aspect of the present invention, it is possible to easily manufacture a fixing roller having a phase change heat generating layer made of polyimide in which particles of the phase change heat generating material are dispersed in polyimide and a surface protective layer formed thereon. A method is provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a layer configuration of a fixing roller 1 of the present invention.

FIG. 2 is a process diagram illustrating an example of a manufacturing process of a fixing roller.

FIG. 3 is a DTA curve diagram showing crystallization heat generation characteristics of an amorphous material according to a reference example.

FIG. 4 is a DTA curve showing crystallization heat generation characteristics of an amorphous material according to a reference example.

FIG. 5 is a DTA curve showing crystallization heat generation characteristics of an amorphous material according to a reference example.

FIG. 6 is a time-temperature curve diagram for explaining a temperature rise characteristic of a fixing roller according to a reference example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fixing roller 2 ... Core metal 3 ... Particles 4 ... Binder 5 ... Phase change heating layer 6 ... Protective layer (surface layer)

Claims (6)

[Claims] 1. A fixing roller having a phase transition heating layer in which particles of a phase transition heating material that generates thermal energy during a phase transition from an amorphous phase to a crystalline phase are dispersed in a binder. A fixing roller formed by agglomeration formed by reduction in a binder solution. 2. A method of manufacturing a fixing roller having a phase-change heating layer in which particles of a phase-change heating material that generates thermal energy during a phase transition from an amorphous phase to a crystalline phase are dispersed in a binder. The step of forming the phase change heat generating layer includes: a mixing step of mixing a raw material to be a phase change heat generating material by reduction with a reducing agent in a binder solution; 2. The method according to claim 1, further comprising: a particle precipitation step of depositing the mixture in the form of particles; and a coating step of coating the mixture on at least a part of the surface of the roller or the inside of the roller. 3. The method according to claim 2, wherein the raw material is selenium dioxide. 4. The method according to claim 2, wherein the reducing agent is at least one selected from the group consisting of handloquinones and hydrazines. 5. The method according to claim 2, wherein the binder solution contains a polyimide precursor.
13. The method for manufacturing a fixing roller according to item 13. 6. A phase-change heating layer made of polyimide in which particles of a phase-change heating material that generates thermal energy during a phase transition from an amorphous phase to a crystalline phase are dispersed in polyimide, and a surface formed thereon. A method of manufacturing a fixing roller having a protective layer, comprising: applying a polyimide precursor dispersion liquid containing particles of a phase-change exothermic material formed by reduction in a polyimide precursor solution to a support; After forming, the phase change heat generating layer is pre-heated at a temperature equal to or lower than the melting point of the phase change heat generating material,
Then, after a surface protective layer is provided, the phase change heat generating layer is heated to be imidized, thereby producing a fixing roller.