JP3215812B2 - Fixing roller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an image forming apparatus such as a copying machine, a printer and a facsimile .
On over La.

[0002]

2. Description of the Related Art In a copying machine, a printer, a facsimile or the like, a fixing device including a fixing roller and a pressure roller is used for fixing a developed image. In this fixing device,
The transfer paper on which the toner has been transferred and developed is passed between a fixing roller and a pressure roller, where the toner is heated and melted (softened) and fused and fixed on the transfer paper.

In this type of fixing roller, warming up is performed in advance until the temperature of the outer peripheral surface reaches a temperature required for fixing (a fixable temperature or a predetermined temperature (for example, 180 ° C.)). . This warm-up requires a long time, and generally employs a configuration in which the fixing roller is preheated when the main power is turned on.

However, the fixing roller having the preheating configuration consumes a large amount of electric power, which is not always desirable from the viewpoints of global environmental protection and energy saving.
Accordingly, the applicant of the present application has provided a phase-change heating layer made of a phase-change heating substance capable of performing a phase transition between amorphous and crystalline, on the outer periphery of the cylindrical cored bar. A fixing roller configured to be covered with a protective layer has been proposed (see, for example,
140823). According to this fixing roller, the heat energy generated when the phase-change exothermic substance undergoes a phase transition from amorphous to crystalline before the temperature of the outer peripheral surface of the fixing roller reaches the fixable temperature by heating the heater. In addition, the temperature rise of the outer peripheral surface of the fixing roller is promoted as compared with the temperature rise only by the heater. This shortens the warm-up time and saves power.

In this type of fixing roller, heat energy generated when the phase-change exothermic substance is crystallized is used. Therefore, in order to reuse the phase-change exothermic substance, it is necessary to use the phase-change exothermic substance. It is necessary that a substance be made amorphous by rapid cooling from a molten state, and be crystallized when the temperature of the amorphous substance is raised.

As this kind of substance, among inorganic substances, it is known that elements of Groups III to VI of the periodic table are multi-elements and have an amorphousizable region. Among them, S
A chalcogen or a chalcogenide compound containing e (selenium) as a main component is a suitable material because it rapidly crystallizes and generates heat, and heat energy during crystallization is large.

[0007] Among organic materials, high molecular materials such as crystalline thermoplastic resins such as polyesters such as PET (polyethylene terephthalate) and PBT (polybutylene terephthalate) have a region capable of being made amorphous. I understand. Further, it has been confirmed that, among low molecular weight organic substances, derivatives of diphenyl isophthalate, bisphenol derivatives and the like generate heat during crystallization.

For example, FIG. 1 shows the thermal analysis characteristics of a typical phase change exothermic substance (Se) by a thermal analyzer (DTA). In FIG. 1, reference numeral L1 indicates a control temperature straight line, and FIG. 1 shows a heat generation-endothermic curve Q when the temperature is raised at a rate of 10 minutes per minute. Sign T
g is the glass transition point of the phase change exothermic substance, Pg and Pm are the endothermic peak of the substance, Pc is the exothermic peak portion of the substance,
Tcp is the exothermic peak temperature of the substance, Tci is the crystallization start temperature when the substance starts a phase transition from amorphous to crystalline, and Tcf is the control temperature when the phase transition by the substance is completed. Is the crystallization end temperature, and Tm is the melting temperature (melting point) of the substance. These temperature characteristic values slightly shift to higher temperatures as the control speed increases.

In the exothermic-endothermic curve Q, a small endothermic peak Pg is first observed at the glass transition point Tg as time elapses (temperature rise). Next, a large exothermic peak Pc due to crystallization is observed, and thereafter, an endothermic peak Pm due to melting is observed.

Incidentally, in order to further shorten the warm-up time, it is necessary to quickly raise the surface temperature of the outer periphery of the fixing roller to a temperature higher than a fixing temperature (softening (melting) of the toner). When the phase-change exothermic material is heated in a temperature range significantly lower than the fixing temperature,
By the time the surface of the fixing roller rises to the fixing-possible temperature, the generated heat is dissipated to the surroundings, and the phase-change exothermic substance cannot be used effectively. On the other hand, even if the phase-change exothermic substance is heated after reaching the fixable temperature, the warm-up time cannot be reduced. Further, if the heat generation temperature range from the start of heat generation to the end of heat generation of the phase change heat generating substance is too high, heat is generated even after reaching a predetermined fixable temperature, so that the material is heated to that temperature or higher. So-called overheating occurs.

However, each phase transition exothermic substance has its own crystallization start temperature Tci and exothermic peak temperature Tc.
It has crystallization temperature characteristics such as p, melting point Tm, and crystallization end temperature Tcf. It is desired that this phase transition exothermic substance has appropriate characteristics. It is desired that the temperature range from the formation start temperature Tci to the melting point Tm is usually 80 to 200 ° C.
It is difficult to select a phase change exothermic substance that can widely cover this temperature range.

The present invention has been made in view of the above circumstances, and can significantly reduce the warming-up time, and increase the degree of freedom in selecting a phase transition exothermic substance, thereby increasing the manufacturing efficiency. It is an object of the present invention to provide a fixing roller, a fixing device, and a method of manufacturing the fixing roller, in which the restriction of the fixing roller is greatly reduced and power saving of the heater can be realized.

[0013]

[0014]

[0015]

[0016]

According to the first aspect of the present invention, there is provided a phase change heat generating layer comprising a phase change heat generating material capable of phase transition between crystalline and amorphous, provided on a core metal, wherein the phase change heat generating material is amorphous. A fixing roller in which a temperature rise is promoted by utilizing heat generated during a phase transition from a crystalline phase to a crystalline phase .
Having a crystallization onset temperature at which a phase transition to crystalline starts
One particle and the same material as the first particle,
Has a crystallization start temperature different from the crystallization start temperature of one particle
That consists of at least two kinds of the second particles, said first particles are coated with a thermally conductive material, thermally conductive material have a melting point higher than the melting point and the second particles of the first particle It is characterized by doing.

According to a second aspect of the present invention, a phase-change heat-generating layer comprising a phase-change heat-generating substance capable of phase transition between crystalline and amorphous is provided on a cored bar, and the phase-change heat-generating substance is amorphous. A fixing roller in which a temperature rise is promoted by utilizing heat generated during a phase transition from a crystalline phase to a crystalline phase .
Having a crystallization onset temperature at which a phase transition to crystalline starts
One particle and the same material as the first particle,
Has a crystallization start temperature different from the crystallization start temperature of one particle
And at least two types of second particles, wherein the first particles and the second particles are dispersed in a thermally conductive material, and the thermally conductive material has a melting point of the first particles and a melting point of the second particles. It has a melting point higher than the melting point.

According to a third aspect of the present invention, a phase-change heat-generating layer comprising a phase-change heat-generating substance capable of undergoing a phase transition between crystalline and amorphous is provided on a cored bar, and the phase-change heat-generating substance is amorphous. A fixing roller in which a temperature rise is promoted by utilizing heat generated during a phase transition from a crystalline phase to a crystalline phase .
Has a first crystallization onset temperature at which phase transition to crystalline starts
A first particle and the same material as the first particle,
Second crystallization different from the first crystallization start temperature of the first particles
And at least two types of second particles having an onset temperature.
The phase change heating layer has a first layer formed by dispersing the first particles in a heat conductive material and a second layer formed by dispersing the second particles in a heat conductive material. Wherein each heat conductive material has a melting point higher than the melting point of the first particles and the melting point of the second particles.

According to a fourth aspect of the present invention, in the fixing roller according to the third aspect, the first crystallization start temperature is set to the first crystallization temperature.
The first layer is higher than the second crystallization start temperature,
It is characterized by being laminated on a layer.

According to a fifth aspect of the present invention, a phase change heat generating layer made of a phase change heat generating substance capable of phase transition between crystalline and amorphous is provided on a cored bar, and the phase change heat generating substance is made of an amorphous material. A fixing roller in which a temperature rise is promoted by utilizing heat generated during a phase transition from a crystalline phase to a crystalline phase .
Has a first crystallization onset temperature at which phase transition to crystalline starts
A first particle and the same material as the first particle,
Second crystallization different from the first crystallization start temperature of the first particles
And at least two types of second particles having an onset temperature.
Ri, wherein the first crystallization start temperature is between the exothermic peak temperature of the second crystallization start temperature and the second particles.

What is described in claim 6 is described in claim 4.
In the fixing roller of the first crystallization start temperature is equal to or lower than the exothermic peak temperature of the second particles.

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

According to the present invention, a cylindrical recess is formed on the outer peripheral surface of a cylindrical core, and a phase transition between crystalline and amorphous can be made in the circumferential recess. Wherein the phase change layer is formed of a phase change heat generating material having at least a first crystallization start temperature and a second crystallization start temperature at which a phase transition from amorphous to crystalline starts. Wherein the phase change exothermic material comprises first particles having a first crystallization onset temperature and second particles having a second crystallization onset temperature,
The particle diameter of the first particles is formed larger than the particle diameter of the second particles, the second particles are coated with a heat conductive material, and the first particles and the second particles are separated by using a heater. The phase transition from amorphous to crystalline by heating, the crystalline phase transition exothermic substance is brought into a molten state, and then cooled using a cooling fan to be transformed into amorphous by the cooling. A protective layer is formed on the outer peripheral surface of the layer, an end of the protective layer is in close contact with an end of the surface of the metal core, and the heater is installed in the hollow of the metal core and controlled by a heater controller,
The heater controller is configured to change the phase change exothermic substance from at least one of a first crystallization start temperature and a second crystallization start temperature to a phase change from an amorphous state to a crystalline state. While controlling the heating of the heater, when melting the first particles and the second particles, heating and controlling the heater to the higher melting point of the melting points of the first particles and the second particles, The cooling fan is configured so that the cooling speed when the first particles are changed from a molten state to an amorphous solid or the cooling speed when the second particles are changed from a molten state to an amorphous solid is the faster cooling speed. The phase change exothermic substance in a molten state is cooled through the protective layer.

[0030]

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION

[0032]

Embodiment 1 Next, an embodiment in which the fixing roller of the present invention is applied to a copying machine will be described with reference to the drawings.

In FIG. 2, the copying machine 1 includes a paper feed cassette 3 detachably mounted on the apparatus main body 2 and a paper feed roller for feeding the transfer paper P set in the paper feed cassette 3 into the apparatus main body 2. 4, a drum type photoreceptor 5 having a photosensitive layer 5a on the surface, a transfer device 6 for transferring a toner image adhered to the drum type photoreceptor 5 to one surface of a transfer sheet P, and fixing the transfer sheet P after the toner transfer. Auxiliary rollers 8, 8 for guiding to the section 7 are provided.

The fixing section 7 includes a pressure roller 9 having an elastic body such as rubber mounted on the outer periphery of a core metal such as aluminum or iron, and a fixing roller 10 which rotates following the rotation of the pressure roller 9. ing. The toner transferred to the transfer paper P guided by the auxiliary rollers 8 is fixed to the transfer paper P by the heat of the fixing roller 10. Thereafter, the transfer paper P is discharged from the discharge port 2a of the apparatus main body 2.

As shown in FIG. 3, the fixing roller 10 has a metal core 11 made of a metal such as an aluminum alloy having a good thermal conductivity. A circumferential recess 11a is formed on the outer peripheral surface of the cored bar 11.
Are formed. Circumferential recess 11 on the outer surface of cored bar 11
A phase-change heating layer 12 is provided in a. The phase transition heating layer 12 is covered with a protective layer 13, and an end 13 a of the protective layer 13 is in close contact with an end 11 b of the core 11. A heater 14 is provided on the inner surface of the metal core 11. Power is supplied to the heater 14 from the wirings 14a, 14a. The heater 14 may be a halogen lamp or the like in addition to the cylindrical body shown in FIG. The fixing roller 10 of this embodiment is basically configured by providing a phase-change heating layer 12 and a protective layer 13 on the outer surface of a cored bar 11, and as shown in FIG. An adhesive layer 15, an electric heating layer, an insulating layer, and the like may be additionally formed as necessary.

The phase transition heating layer 12 is made of a phase transition heating substance capable of phase transition between crystalline and amorphous.
As the phase transition exothermic substance, a substance having two or more crystallization onset temperatures (also referred to as exothermic onset temperatures) at which a phase transition from amorphous to crystalline starts is used. Here, the phase-change exothermic substance constituting the phase-change exothermic layer 12 is made of at least two kinds of substances, for example, a second phase-change exothermic substance that starts a phase transition in a low-temperature region by the heat generated by the heater 14 (low-temperature region phase transition). A heat-generating substance and a first phase-change heat-generating substance (high-temperature-area phase-change heat-generating substance) which starts the phase transition by being induced by the heat generated by the phase transition of the second phase-change heat-generating substance.

The mixture forming the phase change heat generating layer 12 is known to have a crystallization start temperature Tci, a heat generation peak temperature Tcp, a melting point Tm, a crystallization end temperature Tcf, and a crystallization heat generation latent heat Lc shown in Table 1 below. The substance is used as a first phase transition pyrogen and a second phase transition pyrogen. These substances are selectively combined.

[0038]

[Table 1] It is desirable that the phase transition heating layer 12 be made of a material that does not cause mutual reaction and mutual melting at the time of melting.

This is because the power is turned off and then turned on again.
This is because, when performing initialization for utilizing heat generated by the phase transition, the phase-change exothermic substance is once heated to a melting point or more and then cooled and then cooled. Therefore, in order to repeatedly use the phase change exothermic substance, it is necessary that these substances do not interact with each other such as a chemical reaction and that they have no compatibility at the time of melting. When two kinds of substances are compatible at the time of melting, it deteriorates,
Amorphization becomes difficult. In addition, the crystallization start temperature, the exothermic peak temperature, and the melting point may change, which may make recrystallization difficult.

An appropriate phase change exothermic substance is selected by the heater 14 by selectively combining a second phase change exothermic substance which starts exothermic in a low temperature region and a first phase transition exothermic substance which starts exothermic in a high temperature region. The second phase transition exothermic substance is caused to generate heat in a low-temperature heating state, and the surface temperature of the fixing roller 10 is reduced to the second
The temperature is rapidly raised to the crystallization onset temperature of the phase change pyrogen, so that the rapid heat generation by the second phase change pyrogen can induce crystallization of the first phase change pyrogen, thereby fixing. The surface temperature of the roller 10 can be quickly raised. Exothermic phenomena occur only in a narrow temperature range in a single substance with a single crystallization onset temperature, but use a phase-change exothermic substance (mixture) with two or more crystallization onset temperatures, so rapid heating over a wide temperature range Can generate heat.

The reason will be described in more detail with reference to FIG.

FIG. 5 shows a temperature-time characteristic when the conventional fixing roller 10 'is heated (the temperature rise characteristic line A is indicated by a broken line).
And the phase-change heating layer 12 composed of only the second phase-change heating substance
And a fixing roller having a phase-change heating layer 12 made of only the first phase-change heating substance formed thereon. And the temperature-time characteristics (heat-rise characteristic curve C is indicated by a two-dot chain line) when the first phase-change exothermic substance and the second
A graph for comparing and explaining temperature-time characteristics (a temperature rise characteristic curve D is indicated by a solid line) when the fixing roller 10 on which the phase change heat generation layer 12 made of a mixture with a phase change heat generation material is formed is heated. FIG. The conventional fixing roller 1
The configuration of 0 'is shown, for example, in FIG. The fixing roller 10 ′ has a release layer 12 ′ formed on the outer surface of the core 11 ′, and is heated by a halogen lamp 14 ′ provided inside the core 11 ′.

The start-up time of the fixing roller in which the phase-change heating layer 12 is composed of only the second phase-change heating substance can be reduced by t1 minutes compared to the start-up time of the conventional fixing roller 10 '.
The start-up time of the fixing roller in which the phase-change exothermic layer 12 is formed only of the phase-change exothermic material can be shortened by t2 minutes compared to the start-up time of the conventional fixing roller 10 ', and the first phase-change exothermic substance and the second phase-change exothermic heat are obtained. The rise time of the fixing roller 10 in which the phase change heat generating layer 12 is formed from the mixture with the substance can be shortened by t3 minutes compared to the rise time of the conventional fixing roller 10 '.

Exothermic peak temperature Tc of the first phase transition exothermic substance
It is necessary that p1 is lower than the melting point Tm2 of the second phase transition exothermic substance since the second phase transition exothermic substance needs to maintain a solid state. When the second phase transition pyrogen melts,
There is a possibility that the rigidity of the surface of the fixing roller 10 cannot be maintained, the interval of the nip 9 ′ (see FIG. 2) between the pressure roller 9 and the fixing roller 10 cannot be maintained, and the fixing cannot be performed properly. Because there is.

The crystallization onset temperature Tc of the second phase transition exothermic substance
i2 and the exothermic peak temperature Tcp of the second phase transition exothermic substance
2 and the crystallization start temperature Tci of the first phase transition exothermic substance
By combining the first phase transition exothermic substance in which 1 exists and the second phase transition exothermic substance, a gentle temperature rise characteristic curve D can be obtained.

The temperature of the second phase transition exothermic material once drops after its exothermic peak temperature Tcp2, and the fixing roller 10
Although the temperature rise of the second phase transition exothermic substance becomes slow, if the crystallization initiation temperature Tci1 of the first phase transition exothermic substance is present between the crystallization initiation temperature Tci2 of the second phase transition exothermic substance and its exothermic peak temperature Tcp2, the second phase When the temperature of the fixing roller exceeds the crystallization start temperature Tci1 due to the heat generated by the transition exothermic substance, the first
This is because heat generation due to the phase transition heating substance is started, and rapid heat generation due to the first phase transition heating substance overlaps with heat generation due to the second phase transition heating substance. Therefore, the heat generated by the second phase transition heating substance can be effectively used for the heat generation of the first phase transition heating substance.

It is sufficient to perform the heating up to the crystallization start temperature Tci1 of the first phase transition exothermic substance, but it is necessary to heat it to at least the crystallization start temperature Tci2 of the second phase transition exothermic substance.

Here, symbol I indicates a temperature difference between the crystallization onset temperature Tci1 of the first phase transition exothermic substance and the crystallization onset temperature Tci2 of the second phase transition exothermic substance, and symbol II indicates the first phase transition exothermic substance. Shows the temperature difference between the crystallization onset temperature Tci1 and the exothermic peak temperature Tcp2 of the second phase transition exothermic substance, II
I indicates the temperature difference between the exothermic peak temperature Tcp1 of the first phase transition exothermic substance and the exothermic peak temperature Tcp2 of the second phase transition exothermic substance, and IV indicates the temperature difference between the crystallization start temperature Tci2 and the exothermic peak temperature Tcp2. The point E where the temperature is higher than the fixable temperature indicates that overshoot has occurred.

If the overshoot is too large, there is a problem in fixing the toner. Therefore, it is desirable that the exothermic peak temperature Tcp1 of the first phase transition exothermic substance is near the fixing-possible temperature. The temperature due to this overshoot was of a level that caused almost no trouble in the embodiments described below. The heater 14 is controlled in order to maintain a fixing-possible temperature.
Is controlled to be slightly lower than the fixable temperature.

The two kinds of phase transition exothermic substances are in a solid state at the time of copying. Therefore, in order to reuse thermal energy generated when a phase transition from a solid-state amorphous to a solid-state crystalline is made, two kinds of phase-change exothermic substances are once melted. In this case, each substance is melted at a temperature higher than the higher one of the melting point Tm1 of the first phase transition heating substance and the melting point Tm2 of the second phase transition heating substance. Since the exothermic peak temperature Tcp2 of the second phase transition exothermic substance is lower than the exothermic peak temperature Tcp1 of the first phase transition exothermic substance, the melting point Tm2 of the second phase transition exothermic substance is not necessarily the melting point of the first phase transition exothermic substance. This is because it is not always lower than Tm1. That is, the melting point Tm2 of the second phase transition exothermic substance having a low exothermic peak temperature Tcp2 is determined by the exothermic peak temperature Tc2.
In some cases, p1 may be higher than the melting point Tm1 of the first phase transition exothermic substance.

For example, a SeTe alloy containing 8% by weight of Te has a crystallization start temperature Tci of 100 ° C., an exothermic peak temperature Tcp of 150 ° C., and a melting point Tm of 230 °.
C. On the other hand, the SeTe alloy containing 50% by weight of Te has a crystallization start temperature Tci of 90 ° C., an exothermic peak temperature Tcp of 110 ° C., and a melting point Tm of 280 ° C.
It is. Therefore, a SeTe alloy containing 8% by weight of Te and having a crystallization start temperature Tci1 between the crystallization start temperature Tci2 and the exothermic peak temperature Tcp2 is used as the first type phase transition exothermic material, and as the second type phase transition exothermic material. Te50
In the case of using a weight percent containing SeTe alloy, the relationship between the melting points Tm1 and Tm2 is reversed.

The two phase transition exothermic substances undergo a phase transition from a molten state to an amorphous solid by rapid cooling. In this case, cooling is performed at a cooling rate at which the phase-change exothermic substance having a higher melting point undergoes a phase transition from a molten state to an amorphous solid state. By rapidly cooling the two kinds of phase change exothermic substances, each phase change exothermic substance becomes an amorphous solid.

In order to efficiently amorphize the two kinds of phase transition exothermic substances, the freezing point T of the phase transition exothermic substance having a low melting point is required.
The cooling rate is switched in the vicinity of m '(a temperature substantially equal to the melting point Tm). The cooling rate for efficiently amorphizing each phase transition exothermic substance is different for each substance, and the melting point Tm
Amorphous phase-change exothermic material having a high melting point is almost completely amorphized near the freezing point of the phase-change exothermic material having a lower melting point Tm, so that the material is efficiently cooled near the freezing point of the phase-change exothermic material having a lower melting point. This is because switching to a cooling rate that can be achieved improves the amorphousization efficiency.

The cooling rate at which the first phase change exothermic substance changes from a molten state to an amorphous solid and the cooling rate at which the second phase change exothermic substance changes from a molten state to an amorphous solid are determined. The cooling may be performed at a higher cooling rate. As a result, the phase change exothermic substance in the molten state can be promptly transferred to the amorphous solid state. In this case as well, by switching the cooling rate near the freezing point of the phase transition exothermic substance having a low melting point, each phase transition exothermic substance can be efficiently made amorphous. After the completion of the phase transition, the cooling by the cooling fan described later is stopped. The phase change pyrogen is then brought to ambient temperature. In FIG. 5, the symbol F indicates the faster cooling speed, and the symbol G indicates the slower cooling speed. When the heat generated by the phase change heating substance is reused, the fixing roller 10 is reheated by the heater 14.

FIGS. 7 to 10 show specific examples for explaining control from heating / melting to cooling.

As shown in FIG. 7, the shaft 11 is
1e is rotatably held by the support cylinder 11f. A blower fan 20 faces the metal core 11. The blower fan 20 is driven by a motor 21 and the blower fan 2
0 and the motor 21 constitute a cooling unit. Here, the heater 14 is formed of a halogen lamp, and the heater 14 functions as a heating unit for heating the phase change heat generation layer 12 and also functions as a melting unit for melting the crystallized phase change heat generation material. The heater 14 and the motor 21 are controlled by a control unit (CPU).
22. A temperature sensor 23, a main switch 24, and an opening / closing detection switch 25 on a main body panel (not shown) are connected to the control unit 22. The temperature sensor 23 detects the surface temperature of the fixing roller 10.

When the main switch 24 is turned on, the control unit 22 starts energizing the heater 14, and the fixing roller 10 is heated. As a result, each phase-change exothermic substance starts to generate heat at each crystallization start temperature, and the fixing roller 10 is quickly raised to a fixing-possible temperature.

The controller 22 controls the energization of the heater 14 by the temperature sensor 23 so that the surface temperature of the fixing roller 10 maintains the fixing-possible temperature. When the main switch 24 is turned off or the main body panel is opened, the control unit 22 increases the amount of electricity supplied to the heater 14 to melt the phase change exothermic substance. The temperature sensor 23 determines whether or not the phase change exothermic substance has melted based on the surface temperature. The control unit 22 includes the temperature sensor 2
3 to determine the melting of the phase change exothermic substance,
Stop supplying power to Next, at the same time or after a predetermined time, the control unit 22 drives the motor 21 to start cooling the phase change heating substance. The switching of the cooling speed by the control unit 22 is performed when the surface temperature of the fixing roller 10 becomes closer to the solidification point having a lower melting point by the temperature sensor 23. Control unit 2
No. 2 stops blowing when each phase transition exothermic substance becomes amorphous in a solid state. FIG. 8 is a timing chart of the energization control. These controls can also be applied to Embodiments 2 and 3 of the invention described later.

When the main switch 24 is turned on or the main body panel is closed, the control section 22 starts supplying electricity to the heater 14 again, whereby the fixing roller 10 is quickly raised to a fixing-possible temperature. Here, heating and melting are performed by one heater 14, but the heating part and the melting part may be provided separately, and the core 11 is heated. A configuration for directly heating 12 may be employed.

In FIG. 7, the phase-change heating layer 12 is cooled from the inside. However, as shown in FIG. 9, the phase-change heating layer 12 may be forcibly cooled from the outside by the blower fan 20. it can. In this case, it is desirable to blow air toward the nip 9 ′ because deformation of the fixing roller 10 can be prevented. Further, as shown in FIG. 10, when the fixing roller 10 is melted while being rotated and cooled, the pressing force of the pressing roller 9 is uniformly applied to the outer peripheral surface of the fixing roller 10, so that the melting The thickness of the phase change heating layer 12 after cooling can be kept uniform.

Next, various examples of the fixing roller 10 according to the embodiment of the present invention and comparative examples will be described.

[0062]

EXAMPLE 1 Two evaporation sources were set in a vacuum evaporation tank on the surface of a cored bar 11 having an outer diameter of 20 mm, and one of them was Te.
8% by weight of a SeTe alloy, and another one of a derivative of diphenyl isophthalate (molecular weight: about 600, melting point: 21).
0 ° C.), and heats and vapor-deposits both evaporation sources,
The phase change heat generating layer 12 having a thickness of 60 μm was formed.

Thereafter, a heat-shrinkable tube made of PFA was covered and sealed as a protective layer 13, heated to 250 ° C., and rapidly cooled at a cooling rate of 10 ° C. or more per minute to produce a heat generating fixing roller 10 (Table 2). Sample No. 1) shown in FIG.

[0064]

Example 2 Two evaporation sources were set in a vacuum evaporation tank on the surface of a core metal 11 having an outer diameter of 20 mm, and a derivative of diphenyl isophthalate was added to one of them and bisphenol A to another. Diphenyl carbonate-added tri- to pentamer derivatives (molecular weight: about 800, melting point: 215 ° C.) were respectively charged, and the two evaporation sources were heated and vapor-deposited, and the thickness was 60 μm.
m of the phase change heating substance layer 12 was formed.

Thereafter, a heat-shrinkable tube made of PFA is covered as a protective layer 13 and sealed, heated to 230 ° C., and rapidly cooled at a cooling rate of 10 ° C. or more per minute to fix the fixing roller 10.
Was prepared (Sample No. 2 shown in Table 2).

[0066]

Example 3 PET powdered in advance and a SeTe alloy containing 50% by weight of Te were mixed at a ratio of 1: 1 and the mixed powder was applied on the surface of a cored bar 11 having an outer diameter of 20 mm by electrostatic coating. Thus, a phase change heating substance layer 12 having a thickness of 60 μm was formed.

Then, at the stage where the alloy was crystallized by heating rapidly to a temperature of about 150 ° C. and burned on the metal core 11, a heat-shrinkable tube of PFA was covered as a protective layer 13 and sealed. After heating under reduced pressure to
The fixing roller 10 was rapidly cooled at a cooling rate of not less than ° C. to prepare the fixing roller 10 (Sample No. 3 shown in Table 2).

[0068]

Comparative Example 1 A fixing roller 10 was prepared by forming a film on the surface of a cored bar 11 in the same manner as in each of the examples, using the phase change exothermic substances used in Examples 1 to 3 alone. However, SeT
e alloy, a diphenyl isophthalate derivative and a diphenyl carbonate-added bisphenol A derivative formed a film by vacuum evaporation, and PET was formed by a preheating curl method (Sample Nos. 4, 5, 6, 7, and 10 shown in Table 2).
8).

[0069]

Comparative Example 2 SeTe alloy containing 50% by weight of Te and Se
The simple substance and the single substance were put into separate evaporation sources, and these were simultaneously vapor-deposited on the outer surface of the metal core 11 in a vacuum to form the phase-change heating layer 12. Thereafter, a heat-shrinkable tube made of PFA was covered as a protective layer 13 and sealed to form a heat-fixing roller 10 (Sample No. 9 shown in Table 2).

[0070]

Comparative Example 3 A tri- to pentamer derivative obtained by adding diphenyl carbonate to bisphenol A used in Example 2 and a bisphenol A derivative were charged into separate evaporation sources, and these were placed on the outer surface of the core metal 11. The phase change heat generating layer 12 was formed by simultaneous vapor deposition in a vacuum. Thereafter, a heat-shrinkable tube of PFA was covered as a protective layer 13 and sealed to form a fixing roller 10 (Sample No. 10 shown in Table 2).

The heat fixing roller 10 of each of Examples 1 to 3 and Comparative Examples 1 to 3 was manufactured by using an electrophotographic copying machine M210 manufactured by Ricoh Company.
Of the fixing roller was heated at a heater power of 960 W, and an increase in the surface temperature of the fixing roller was examined.
Table 2 shows the experimental results of the following examples and comparative examples.

[0072]

[Table 2] As a result, in the example, as shown in FIG. 5, the rise in the surface temperature becomes a form in which the crystallization heat generation patterns of the two phase change substances are compounded, and the crystallization start temperature Tci2 of the second phase change heat generation substance is increased. A rapid rise in temperature occurred and the temperature rose continuously, and good results were obtained. When the temperature is increased only by the second phase transition exothermic substance, the crystallization start temperature Tci2 is low, so that the temperature rise effect is weakened due to shortness of the gas near the fixable temperature. However, the start of heating was delayed by a higher amount. When the two phase transition exothermic substances have similar properties, the temperature rise due to the two phase transition exothermic substances is separately recognized at the initial stage. Not confirmed.

The phase-change heating layer 12 may be formed of a mixture of three or more kinds of phase-change heating substances.

As described above, by positively utilizing the fact that the phase-change exothermic substance has an inherent temperature characteristic, two types of phase-change exothermic substances having a temperature increasing action that is more rapid than that of the heater 14 alone are used. The phase change heat generating layer 12 is formed, and by the heat generated by the phase change heat generating layer 12, a rapid temperature rising effect can be obtained from a relatively low temperature in a stepwise manner. Power saving was achieved.

Further, when the temperature is raised in a temperature range from normal temperature to a fixing temperature in an environment where a copying machine is used, substances having different crystallization temperature characteristics (referred to crystallization start temperature, exothermic peak temperature, etc.) may be used. Since it was decided to form the phase transition heating layer 12 by mixing, depending on the combination of the substances used,
The selection of the temperature range became easy.

[0076]

Second Embodiment In the first embodiment of the present invention, the phase-change exothermic layer 12 is formed from a mixture of the first and second phase-change exothermic materials. In Embodiment 2 of the present invention, the phase-change exothermic layer 12 is composed of a first layer made of only the first phase-change exothermic substance and a second layer made of only the second phase-change exothermic substance. Since this operation and effect are substantially the same as those of the first embodiment of the invention, a detailed description thereof will be omitted, and only different portions will be described.

FIG. 11 shows a phase change heating layer 12 as a first layer 12a.
And a second layer 12b, and the protective layer 13 covers the phase-change heating layer 12. First layer 12a
Is composed of only the first phase change heating substance, and the second layer 12b
Is composed of only the second phase transition exothermic substance, and the first layer 12a
Are formed on the second layer 12b. here,
The crystallization start temperature of the first phase transition exothermic substance is referred to as a first crystallization start temperature, and the crystallization start temperature of the second phase transition exothermic substance is referred to as a second crystallization start temperature. The first crystallization start temperature is higher than the second crystallization start temperature.

As shown in FIG. 12, the phase change heating layer 12 has a crystallization start temperature between the first layer 12a and the second layer 12b, which is different from the first crystallization start temperature and the second crystallization start temperature. A third layer 12c consisting only of a phase change exothermic substance existing between the first and second layers may be provided.

Further, as shown in FIG.
A partition layer 12d having a high thermal conductivity such as an aluminum alloy may be interposed between the first layer 12b and the first layer 12a. The melting point of the partition layer 12d is the melting point T of each phase transition exothermic substance.
It is desirable to use one higher than m1 and Tm2.
This is to prevent the respective phase transition exothermic substances from fusing with each other at the time of melting. When a combination of compatible substances is used, it is desirable to provide the above-described partition layer 12d.

The materials shown in Table 1 are used for the first layer 12a and the second layer 12b as in the first embodiment of the present invention.

Hereinafter, various examples of the fixing roller 10 according to the second embodiment of the present invention and comparative examples will be described.

[0082]

Embodiment 1 A second layer 12b is formed by applying a coating liquid in which a derivative of diphenyl isophthalate is dispersed on the outer surface of a core metal 11 made of an aluminum alloy having an outer diameter of 20 mm.
After drying the second layer 12b, it is set in a vacuum evaporation tank, and selenium tellurium (SeTe) containing 8% by weight of Te is used.
The current is heated by using the alloy as an evaporation source, and the second layer 12b is heated.
To form a first layer 12a having a thickness of 60 μm.

Thereafter, a heat-shrinkable tube made of a perfluoroalkoxy fluororesin (PFA) is put on the first layer 12a, sealed, heated to 250 ° C., and then rapidly cooled at a cooling rate of 10 ° C. or more per minute to fix the fixing roller 10a. (Table 3)
Sample No. 1) shown in FIG.

[0084]

Example 2 Two evaporation sources were set in a vacuum evaporation tank on the outer surface of a cored bar 11 having an outer diameter of 20 mm, and a diphenyl isoflurate derivative was charged into one of them and bisphenol was added to the other. A is charged with a derivative of a tri- to pentamer obtained by adding diphenyl carbonate to A, and first, an evaporation source of the derivative of diphenyl isoflurate is heated and vapor-deposited to form a second layer 12b. The first layer 12a is formed by applying a current to the derivative by heating and heating, and a thickness of 6
A 0 μm phase change heat generating layer 12 was formed.

Thereafter, a heat-shrinkable tube made of PFA is put on and sealed to form a protective layer 13, which is heated to 220 ° C., quenched at a cooling rate of 10 ° C. or more per minute, and fixed.
Was prepared (Sample No. 2 shown in Table 2).

[0086]

Example 3 A SeTe alloy containing 8% by weight of Te was vacuum-deposited on the outer surface of a core metal 11 having an outer diameter of 20 mm on which a PET film (second layer 12b) was previously formed by a preheating curl method. 12a) was formed to form two phase change heat generating layers 12 having a thickness of 60 μm.

Thereafter, a protective layer 13 is formed by covering with a heat-shrinkable tube of PFA to form a protective layer 13, heated under reduced pressure to 285 ° C., and rapidly cooled at a cooling rate of 50 ° C. or more per minute to fix the fixing roller 1.
0 was created (Sample No. 3 shown in Table 2).

[0088]

Embodiment 4 After forming a SeTe alloy containing 50% by weight of Te as a second layer 12b on the outer surface of a core metal 11 having an outer diameter of 20 mm by vacuum evaporation, a stainless steel film (partition layer 12d) is formed on the surface by sputtering. Then, a SeTe alloy containing 8% by weight of Te was formed thereon as the first layer 12a.

Thereafter, a protective layer 13 was formed by covering with a heat-shrinkable tube of PFA to form a protective layer 13. After heating under reduced pressure to 285 ° C., it was rapidly cooled at a cooling rate of 10 ° C. or more per minute to form a fixing roller 10. Sample No. shown in 2
4).

[0090]

Embodiment 5 A second layer 12b is formed by applying a coating liquid in which a derivative of diphenyl isophthalate is dispersed on the outer surface of a cored bar 11 having an outer diameter of 20 mm, and after the second layer 12b is dried, After curling a PET sheet on which an aluminum film (partition layer 12d) has been formed in advance by preheating with the aluminum film surface inside, the core metal 11 having the second layer 12b formed thereon
The first layer 12a was formed on the substrate.

Thereafter, a protective layer 13 was formed by covering with a heat-shrinkable tube made of PFA to form a protective layer 13, heated under reduced pressure to 250 ° C., and rapidly cooled at a cooling rate of 50 ° C. or more per minute to form a fixing roller 10 (see Table 1). Sample No. shown in 2
5).

[0092]

COMPARATIVE EXAMPLE 1 The phase change exothermic substances used in Examples 1 to 3 were individually formed on a support of a cored bar 11 in the same manner as in Example. However, the SeTe alloy, the diphenyl isophthalate derivative, and the diphenyl carbonate-added bisphenol A derivative form a film by vacuum evaporation, and PET is formed by a preheating curl method (see Table 2).
sample Nos. 6, 7, 8, 9).

[0093]

COMPARATIVE EXAMPLE 2 The two kinds of SeTe alloys of Example 4 were sequentially laminated by vacuum evaporation to form a second layer 12b and a first layer 12a, which were then sealed with a PFA heat-shrinkable tube. The fixing roller 10 was manufactured as the protective layer 13 (Sample No. 10 shown in Table 2).

[0094]

Comparative Example 3 In the same manner as in Example 5, there was no aluminum coating between the second layer 12b and the first layer 13a (partition layer 1).
A fixing roller 10 (without 2d) was produced (S shown in Table 2).
sample No11).

The fixing rollers 10 of Examples 1 to 5 and Comparative Examples 1 to 3 were incorporated in a fixing device of an electrophotographic copying machine M210 manufactured by Ricoh, and the surface temperature of each fixing roller 10 was increased while heating with a heater power of 960 W. I checked the situation.
Table 3 shows the experimental results of the following examples and comparative examples.

[0096]

[Table 3] Although the comparison result was almost the same as that of the first embodiment of the invention, when the compatible substances were laminated and formed as in Comparative Examples 2 and 3, the crystallization start temperature gradually shifted due to repeated use, In addition, the heat generation has also deteriorated.
In the case where the partition layer 12d was formed between the first layer 12a and the second layer 12b as shown in 5, the crystallization start temperature was stable even after repeated use.

[0097]

Third Embodiment In the first embodiment of the present invention, two different kinds of phase-change exothermic substances are mixed to form a phase-change exothermic layer 12 on a metal core 11. In the second embodiment of the present invention, the second layer made of only a single phase change exothermic substance and the first layer are laminated to form the phase change exothermic layer 12 composed of at least two layers on the metal core 11.

However, when two or more phase transition exothermic substances are used, in addition to the selection of the crystallization temperature range, the properties such as the compatibility, melting point, and glass transition point of the two or more substances are extremely well selected. There is a need to. Therefore, in the first and second embodiments of the invention, the application range of the substance is still limited.

For example, when melting the crystallized phase-change heating layer 12, the phase-change heating substance having a melting point of about 300 ° C. or more is too high in consideration of the firing point temperature of the transfer paper P. On the other hand, when the melting point is lower than the fixable temperature, the phase transition exothermic substance is absorbed when the temperature rises and the phase transition exothermic substance is melted. As a result, the temperature rise of the fixing roller 10 is not promoted, but rather decelerated. When the glass transition point is lower than room temperature, the non-crystallized phase transition heating layer is crystallized with time. In addition, if compatible, the two phase change pyrogens are mutually dissolved.

In general, the crystallization temperature (T
(ci, Tcp, Tcf) is a temperature peculiar to the substance, and was thought to be determined by the phase-change exothermic material used. Similarly, the glass transition point Tg and the melting point Tm are also generally temperatures inherent to the substance. Therefore, if one selects materials with different crystallization temperatures, the melting points are expected to be different as well.

However, according to the study of the present inventors,
The phase change exothermic material generally has an intrinsic crystallization temperature, but by performing a specific treatment, for example, a pulverization treatment, a second crystallization exotherm lower than the intrinsic crystallization temperature of the original bulk. It has been found that properties having temperature can be improved. As a result, the crystallization temperature range of the phase transition could be expanded while maintaining the melting point Tm and the glass transition point Tg, which are the intrinsic values of the phase transition exothermic material.

It is presumed that this phenomenon is caused by crystal growth conditions such as the directionality of the crystal growth rate and the anisotropy of the growth rate. For example, it is known that the shape of a crystal changes under the conditions during crystal growth, such that snow, which is a crystal of water, has a so-called snow-mark-shaped plane dendrite shape or a stone-shaped cone like quartz. I have.

The reason for the change in the crystallization pattern depending on the crystallization particle size of the Se-based amorphous material can be considered, for example, as follows.

The activation enthalpy of crystallization of the double peak generated in Se is 1.3 eV at the low temperature region peak.
(379 cal / g), 1.0 eV (2
92 cal / g). Similarly, a measurement result that the activation enthalpy of the peak in the low temperature region is high is obtained for a SeTe alloy containing 6 wt% (wt%) of Te. This indicates that the high temperature region peak is easily crystallized, and the low temperature region peak is not easily crystallized. Therefore, it is considered that crystallization based on this low-temperature region peak is unlikely to occur in a lump since the low-temperature region peak has a higher activation enthalpy than the high-temperature region peak.

Here, in the case of chalcogen such as Se, when a lump is pulverized, bonds are cut at the fractured surface, and countless dangling bonds are generated. When this dangling bond is left in the air, it is combined with oxygen and stabilized. On the other hand, it has been confirmed that Se becomes easily crystallized as the oxygen concentration increases (Japanese Patent Application No. Hei 7-144130).
No.). Summing up these facts, it is presumed that the dangling bonds themselves also act as crystal nuclei, but the stabilized dangling bonds also act as crystal nuclei. Thus, it is considered that the miniaturization contributes to generating a large number of crystal nuclei for promoting crystal growth on the surface.

In the case of chalcogens such as Se, the crystal growth form in the lump is spherulite, but when the crystal form of the vapor-deposited thin film is often observed, large jelly-like or mushroom-like plane radial crystals are observed. This is thought to be due to the fact that this material has a higher crystal growth rate on the surface than growth in bulk. It is considered that the miniaturization contributes to the increase of the surface having a high crystal growth rate.

Therefore, in this substance, a number of crystal nuclei are generated on the surface of the particles by finer particles to promote crystallization, and crystallization is considered to be faster than in a lump. It is believed that the increase further promotes crystallization. Therefore, crystallization is promoted by a large number of crystal nuclei on the particle surface generated by the refinement and an increase in the particle surface area due to the refinement, and the enthalpy of activation is high due to the promotion of these crystallizations. Is assumed to appear.

Although the crystallization mechanism of the organic polymer is complicated, it is presumed that the relationship between the free surface and the inside of the lump (bulk) is basically the same. That is, the expression of the second crystallization peak is promoted by increasing the surface area by miniaturization or by attaching a known crystal nucleating agent to the surface of the polymer particles.

Since this phase transition exothermic substance has a plurality of crystallization exothermic temperatures, this promotion is performed in a relatively wide temperature range as compared with a phase change exothermic substance having a single crystallization exothermic temperature. Therefore, the heat generation is started from a relatively low temperature, and can be accelerated to a high temperature near the fixing temperature of the fixing roller. further,
This is the same substance, and is a material having a single endothermic temperature based on melting. Therefore, in the case of melting for amorphization, the material may be heated to a single melting point or higher. Therefore, material selection becomes easier as compared with the case where a plurality of different substances are used.

The phase change heat generating layer 12 having two or more crystallization onset temperatures can be formed by selectively using the same substances having different particle diameters in combination.

For example, if an alloy mainly composed of a chalcogen-based element is pulverized into fine particles, a new crystallization start temperature can be generated in a low temperature region. Further, among the chalcogen-based element alloys, Se has a melting point of 217 ° C. , so that the melting point does not shift significantly even when it becomes an alloy. Therefore, it can be effectively performed without requiring a high temperature in the melting process of the amorphous initialization.

The substance constituting the phase transition heating layer 12 includes high purity Se (purity 99.
(999%) pellets are used. According to the inventor's research, the second crystallization onset temperature is developed when the mass is crushed. Therefore, in order to confirm this phenomenon, the pellets were pulverized with a pulverizer, and the obtained powder was lumped to 0.5 mm or more,
Classify into 0.2-0.5 mm powder, fine powder less than 0.1 mm. Each sample was subjected to thermal analysis DTA under the condition of a heating rate of 10 ° C./min, and the results are summarized in Table 4.

[0113]

[Table 4] As shown in FIG. 14, the lump of sample number 1 shows a heat generation pattern due to crystallization similar to that of FIG. 1, and shows a sharp heat generation peak temperature Tcp at 140 ° C.

On the other hand, in the case of the fine powder of Sample No. 3 having a particle diameter of less than 0.1 mm, which was mechanically pulverized, a relatively large calorific value in which the peak portion of the calorific pattern spread to the low temperature side as shown in FIG. Was observed. Further, the materials of sample numbers 2 and 3 exhibit a low-temperature exothermic peak temperature Tcp2 (110 ° C.) in addition to the high-temperature exothermic peak temperature Tcp1 (140 ° C.). It is understood that the material has a range of exothermic regions. Further, the crystallization start temperature is also shifted to the lower temperature side. Thus, it is understood that the crystallization start temperature can be controlled by a simple structure of controlling the particle size. Further, it is understood that the materials of Sample Nos. 2 and 3 are effectively used as materials for accelerating the temperature rise in a wide range from the low temperature side to the high temperature side.

In particular, the material of sample No. 3
It is understood that the heat generation pattern is broader than that of the material No. 3, and the material of sample No. 3 is expected to have an effect of smoothly and continuously promoting the temperature increase over a wide area. The materials of Samples 2 and 3 have melting points T
Both m and the glass transition point Tg were not substantially changed from the material of Sample No. 1.

On the other hand, as a control, the same pellet was vacuum-deposited at a support substrate temperature of 50 ° C. to form a deposited film having a thickness of 0.1 mm and peeled off to obtain a deposited film sample (sample No. 4). When thermal analysis DTA was performed in the same manner, FIG.
The heat generation pattern was the same as that of Example 1. The results are also shown in Table 4. In the case of a deposited film, the second
No exothermic peak was observed.

Similarly, a SeTe alloy containing 6% by weight of Te and a SeT alloy containing 50% by weight of Te are used instead of high-purity Se.
e alloy (melting point 285 ° C)
When TA was performed, as shown in FIG. 16, the exothermic peak temperature slightly shifted to a higher temperature side as compared with high-purity Se based on the Te composition, but showed exactly the same behavior as Se.
Two exothermic peaks were observed in the milled material.
This confirms that the chalcogenide compound exhibits the same behavior as Se.

These finely divided Se and SeT
It has been confirmed that the DTA pattern of the e-alloy maintains the initial double peak pattern even when the sample is left for several years. Therefore, it is understood that durability is good even when this finely pulverized sample is used as a material constituting the transition layer of the heating roll.

As is clear from the above description, according to the third embodiment of the present invention, the temperature range of the heat generation can be controlled by controlling the particle diameter of the phase transition heat generating substance. For example, by reducing the particle size, a substance that generates more heat in a low temperature range can be obtained.

That is, if the same substances having different particle diameters are selectively combined, as described in the first and second embodiments of the present invention, the temperature can be changed from the low temperature region to the high temperature region. It is possible to form the phase transition heating layer 12 that is heated over a wide temperature range. The phase change heat generating layer 12 may have a single-layer structure made of a mixture of the first particles 30 and the second particles 31 as shown in FIGS.

When the phase-change heat generating layer 12 is composed of a single layer of a mixture of the first particles 30 and the second particles 31, the first particles 30 and the second particles 31 are mixed over the entire surface to form a uniform layer. It is desirable to adopt a configuration in which the components are dispersed.

Since the phase transition heating layers 12 are made of the same substance, the melting point Tm and the freezing point Tm 'are the same. For this reason,
The melting point of the first particles 30 and the second
The particles 31 need to be held by a thermally conductive form holding material having a melting point higher than the melting point. In particular, the first
Since the second particles 31 having a smaller particle diameter than the particles 30 have a crystallization start temperature lower than the crystallization start temperature of the first particles 30, in order to maintain the crystallization start temperature of the second particles 31, As shown in FIG. 17, it is desirable to coat with the form holding material 34, but as shown in FIG. 18, both the first particles 30 and the second particles 31 may be covered with the form holding material 34.

As shown in FIG. 19, the first particles 30
The second particles 31 may be uniformly dispersed and mixed in the thermally conductive form holding material 35 having a melting point higher than the melting points of the respective particles 30 and 31. In this case, it is not necessary to coat each particle 30, 31.

Further, as shown in FIG.
Is uniformly dispersed in the thermally conductive form-holding material 36 so that the first
The second layer 33 is formed by uniformly dispersing the second particles 31 in the thermally conductive form-holding material 37, and the first layer 32 and the second layer 33 form the phase transition heating layer 12. May be formed. In this case, like the first embodiment of the invention, the first layer 3 composed of only the first particles 30 having a high crystallization start temperature is used.
2 is desirably formed on the second layer 33 composed of only the second particles 31. Note that a vapor deposited film may be used as the first phase change heating substance.

An epoxy-based adhesive or a thermoplastic polyimide-based adhesive is used as the thermally conductive form-holding material. In order to make the phase-change exothermic substance amorphous while covering the particles, Any material may be used as long as it can maintain the initial particle form by maintaining the form without melting or decomposing the coating film in a state where the phase change heating substance is melted. Such materials include, for example, cross-linked polymers and high melting point polymers.

In these examples, in order to cause a phase transition from a crystallized solid to an amorphous solid, the crystallized solid is brought into a molten state, and the liquid in the molten state is rapidly cooled to obtain an amorphous state. However, the crystallized solid can be phase-transformed to an amorphous solid by implanting ions into the crystallized solid. In this case, the ion implanter may be incorporated in the copying machine.

According to the third embodiment of the present invention, a wide range of heating can be promoted with the same substance, and the restrictions on manufacturing are greatly reduced as compared with the case where a plurality of different types of phase transition exothermic substances are used.

By uniformly dispersing substances having different particle diameters, the effect of promoting the temperature rise becomes uniform over the entire roller.

The mechanical crushing can increase the crystallization temperature of the phase change exothermic substance.

Even if the phase-change exothermic substance is melted for amorphization, it is protected and separated by the coating.
The particles do not dissolve in each other and always maintain the same particle shape for repeated use. Further, since the coating material has good thermal conductivity, the heat transfer efficiency of generated heat is good.

An alloy mainly composed of a chalcogen element can easily generate a low-temperature crystallization exothermic temperature by pulverizing the alloy into fine particles.

[0132] Among the chalcogen-based element alloys, Se has a melting point of 217 ° C. Therefore, even when an alloy is formed, the melting point does not significantly change and the melting for the amorphous initialization can be performed effectively.

[0133]

As described above, the fixing roller of the present invention is
La is the phase transition heating substance that constitutes the phase transition heating substance layer,
Since it has two or more types of crystallization onset temperatures, it is possible to significantly reduce the warm-up time, and
The temperature range can be easily selected, and power saving of the heater can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic DTA curve diagram for explaining the exothermic characteristics of a phase change exothermic substance.

FIG. 2 is a sectional view showing a schematic configuration of a copying machine according to an embodiment of the present invention.

FIG. 3 is an enlarged sectional view illustrating an example of a configuration of a fixing roller according to the exemplary embodiment of the present invention.

FIG. 4 is an enlarged sectional view showing a modification of the fixing roller according to the present invention.

FIG. 5 is a schematic diagram showing a temperature-time curve for explaining a temperature rise characteristic of the fixing roller according to the present invention.

FIG. 6 is a cross-sectional view illustrating a configuration of a conventional fixing roller.

FIG. 7 is a configuration diagram illustrating control of a fixing device according to the present invention.

8 is a diagram showing control timing of the fixing device shown in FIG.

FIG. 9 is a schematic diagram illustrating a configuration for cooling an outer peripheral surface of a fixing roller.

FIG. 10 is a schematic diagram illustrating a cooling configuration while rotating a fixing roller.

FIG. 11 is an enlarged cross-sectional view of a fixing roller having a two-layer structure of a first layer and a second layer as a phase change heat generating layer.

FIG. 12 is an enlarged cross-sectional view of a fixing roller having a three-layer structure including a first layer, a second layer, and a third layer as a phase transition heating layer.

FIG. 13 is an enlarged cross-sectional view of a fixing roller having a two-layer structure of a phase-change heat generating layer including a first layer and a second layer, and a partition layer provided between the first layer and the second layer.

FIG. 14: DT showing crystallization exothermic characteristics of high-purity Se lump
It is an A curve figure.

FIG. 15D shows the crystallization exothermic characteristics of high-purity Se fine powder.
It is a TA curve figure.

FIG. 16 is a graph showing a heat generation characteristic of crystallization of SeTe alloy powder.
It is a TA curve figure.

FIG. 17 is a partially enlarged view of a fixing roller showing a state in which the same substance having different particle diameters are mixed to form a phase-change exothermic substance on a core metal, and particles having a smaller particle diameter retain a heat conductive form; The state covered with the material is shown.

FIG. 18 is a partially enlarged view of a fixing roller in which first particles and second particles of the same substance and having different particle diameters are mixed to form a phase-change exothermic substance on a cored bar; 2 shows a state covered with a shape maintaining material.

FIG. 19 is a partially enlarged view of a fixing roller in which first and second particles having different particle sizes are mixed and uniformly dispersed in a thermally conductive material to form a phase change heat generating layer.

FIG. 20 is a partially enlarged view of a fixing roller in which a phase change heating layer is formed by a first layer made of only first particles of the same substance and a second layer made of only second particles.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Fixing roller 11 ... Core metal 12 ... Phase transition heating layer 30 ... 1st particle 31 ... 2nd particle

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G03G 13/20 G03G 15/20 F16C 13/00

Claims (6)

(57) [Claims] 1. A phase-change heat-generating layer comprising a phase-change exothermic material capable of phase transition between crystalline and amorphous is provided on a core metal, and the phase-change exothermic material undergoes a phase transition from amorphous to crystalline. In the fixing roller in which the temperature rise is promoted by utilizing the heat generated during the heating, the phase change exothermic substance starts a phase transition from amorphous to crystalline.
First particles having a crystallization onset temperature, and the first particles
The crystallization start temperature of the first particles, which is composed of the same substance
At least a second particle having a crystallization onset temperature different from
A fixing roller , wherein the first particles are coated with a heat conductive material, and the heat conductive material has a melting point higher than a melting point of the first particles and a melting point of the second particles. 2. A phase transition heating layer comprising a phase transition heating substance capable of phase transition between crystalline and amorphous is provided on a core metal, and the phase transition heating substance is changed from an amorphous phase to a crystalline phase. In the fixing roller in which the temperature rise is promoted by utilizing the heat generated during the heating, the phase change exothermic substance starts a phase transition from amorphous to crystalline.
First particles having a crystallization onset temperature, and the first particles
The crystallization start temperature of the first particles, which is composed of the same substance
At least a second particle having a crystallization onset temperature different from
And the first particles and the second particles are dispersed in a heat conductive material, and the heat conductive material has a melting point higher than the melting point of the first particles and the melting point of the second particles. Fusing roller. 3. A phase change heating layer comprising a phase change heating substance capable of phase transition between crystalline and amorphous is provided on a core metal, and the phase transition heating substance is changed from an amorphous phase to a crystalline phase. In the fixing roller in which the temperature rise is promoted by utilizing the heat generated during the heating, the phase change exothermic substance starts a phase transition from amorphous to crystalline.
Particles having a first crystallization onset temperature, and the first particles
First crystallization of the first particles, the first crystallization being made of the same material as the particles
Second grains having a second crystallization onset temperature different from the onset temperature
And a phase transition heating layer, wherein the first layer is formed by dispersing the first particles in a thermally conductive material, and the second particles are dispersed in a thermally conductive material. And a second layer formed by the following method, wherein each heat conductive material has a melting point higher than the melting point of the first particles and the melting point of the second particles. 4. The fixing roller according to claim 3, wherein
The first crystallization start temperature is higher than the second crystallization start temperature
A fixing roller , wherein the first layer is stacked on the second layer. 5. A phase transition heating layer comprising a phase transition heating substance capable of phase transition between crystalline and amorphous, provided on a cored bar, wherein said phase transition heating substance changes from amorphous to crystalline. In the fixing roller in which the temperature rise is promoted by utilizing the heat generated during the heating, the phase change exothermic substance starts a phase transition from amorphous to crystalline.
Particles having a first crystallization onset temperature, and the first particles
First crystallization of the first particles, the first crystallization being made of the same material as the particles
Second grains having a second crystallization onset temperature different from the onset temperature
And a fixing roller , wherein the first crystallization start temperature is between the second crystallization start temperature and the heat generation peak temperature of the second particles. 6. The fixing roller according to claim 4, wherein
The first crystallization start temperature is lower than a heat generation peak temperature of the second particles.