JPS63158583A - Heat fixing roller - Google Patents

Abstract

PURPOSE:To simplify the structure of the titled roller, and to make the titled roller inexpensive, and to improve reliability of the titled roller by using a layer composed of a Ni-contg. material which is formed by fusing under heating a sheet-like material and is composed mainly of a nickel-boron alloy and a glass binder, as a resistance heating element on a cylindrical substrate body. CONSTITUTION:A paste composed of the nickel-boron alloy (NiB), the glass binder and a vehicle, is printed on a transfer paper so as to form a film having a prescribed film thickness according to a printing method, followed by drying it. The surface of the obtd. film is effected a resin coating treatment, followed by drying it. The obtd. film is transferred on the cylindrical substrate body which is previously coated the transfer solution, followed by heating it. Subsequently, the obtd. film is baked in the air to burn a combustible component such as the vehicle, etc., and to convert NiB in the glass binder to a conductive Ni. The layer composed of the obtd. Ni-contg. material is applicable to the resistance heating element. Thus, the structure of the titled roller is simplified, and the titled roller is made to inexpensive and the reliability of the titled roller is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is particularly applicable to a heating source for a heating stone roll of a device used in equipment using an electrophotographic process such as an electrophotographic copying machine, a facsimile machine, and a printer. Regarding a certain resistance heating element layer.

[Prior Art] In an electrophotographic process, a toner image formed on a photoreceptor is generally transferred onto a recording support, such as paper, by a transfer device, and then, if necessary, the toner image is fixed on the surface of the paper to form a desired image. I have obtained a copy etc.

Known methods for fixing toner images include a heat fixing method, a pressure fixing method, and a solvent fixing method.

The heating method 6 is a method in which toner is melted and adhered to paper using Ill heat, and is widely used.

There are various heat fixing methods, such as a hot air fixing method, an oven fixing method, and a heated roll fixing method, but the heated roll fixing method is the most common.

As shown in FIG. 3, the heating roll type fixing device that has been commonly used in the past consists of a heating roll 1a and a pressure roll 10a, the heating roll 1a having an internal heating element 25 housed therein; When the paper 20 is conveyed while being held between the pressure roll 10a, heat and pressure are applied to fix and cover the unfixed toner image 21 on the surface of the paper 20 transferred from the photosensitive drum.

[Problem to be Solved by the Invention 1] In a heating roll type fixing device using such an internal heating element 258, a lamp such as a halogen lamp is used as the heating element (heat source), but the surface temperature of the roll In order to raise the temperature to a certain level required for heat fixing, it is necessary to heat the entire roll from inside with a lamp. Therefore, in conventional fixing devices, 1
A warm-up time of about 10 minutes is required. Therefore, there is a lost time during which no copying operation can be performed from when the operator turns on the switch until it warms up. In addition, because heat loss is large, power consumption is relatively large, and furthermore, a temperature control device, a surface temperature sensor, etc. are required, and the use of expensive halogen lamps increases costs and makes the structure extremely complicated. It also has drawbacks such as low reliability against failures.

As another heating method, a method has been proposed in which a heating element is formed near the outer peripheral surface of the heating roll using a semiconductor ceramic material having self-temperature control characteristics (PTC characteristics), and heating is performed from near the surface of the roll. It is difficult to actually obtain a PTC ceramic material whose resistance rises to a desired value, and especially when forming a film-like heating element on the roll surface, it is extremely difficult to control the resistance value.
For example, when the design value is set to 180'C, if the rising temperature of the resistor deviates from 180°C, there is a problem that it becomes impossible to heat the heating element by electricity.

Accordingly, an object of the present invention is to provide a heat fusing roll which eliminates the drawbacks of the prior art in the heating element of a heat fusing roll, shortens warm-up time, saves power, simplifies the structure, lowers costs, and improves reliability. Our goal is to provide the following.

[Means for Solving the Problems] As a result of extensive research into a heating fixing roll in which a thin film-like resistance heating layer is provided on a cylindrical support, the present inventors found that nickel was used as the material for the resistance heating element. It has been discovered that the above object can be achieved by using a Ni-containing stone material layer made by heat-sealing a sheet material containing a boron alloy and a glass binder as main components to a cylindrical support, and has developed the present invention. completed.

That is, the present invention provides a heating fixing roll in which a resistive heating element layer is provided around a support, in which a sheet-like material containing a nickel-boron alloy and a glass binder as the main components is attached to the outer periphery of the support. This is a heat fixing roll characterized by using a layer formed by winding the film and then heating and baking it.

Hereinafter, the preparation of the heat fixing roll of the present invention will be explained in detail.

In the heat fixing roll of the present invention, as shown in the process diagram in Fig. 4, a paste consisting of a nickel-boron alloy (hereinafter referred to as NiB), a glass binder, and a vehicle is applied onto a transfer paper using a printing method. II!J is printed in the form of a loaf and dried, then the surface is coated with a resin, dried, transferred to a cylindrical support coated with a transfer liquid, dried, and then baked in the air to form a vehicle. This Ni-containing layer can be used as a resistance heating element by burning off combustible components such as, and changing the NiB in the glass binder into conductive Ni.

In NIB, the ratio of Ni and B exists in an almost arbitrary ratio, and 1q
However, NiB suitable as a raw material for the resistance heating element of the heat fixing roll of the present invention has a B content in the range of 1 to 20% by weight, and commercially available N1B (B content of about 10 to 12
% by weight) is preferably used. If the B content is less than 1% by weight, Ni will be oxidized during the firing process in the atmosphere to form non-conductive nickel oxide, and if it exceeds 20% by weight, moisture resistance will be poor, which is not preferable.

The glass binder is fused to the ceramic or enamel surface used as a support by firing.
It is used to form a strong resistance heating layer, and preferably a material whose coefficient of thermal expansion is close to that of the support material is selected and used.

The combination of NiB and glass binder used can vary within a wide range. In other words, the NiB ratio is 10~
96% by weight, preferably 20-80% by weight (therefore glass binder 4-90%, preferably 20-8%)
Use within the range of 0%).

The vehicle is used as a printability improver for good printing on the transfer sheet using a powdered glass binder and NiB as a paste.

As a vehicle, 2 to 15 parts by weight of a binder such as a material commonly used in the printing field, such as ethyl cellulose, nitrocellulose, or acrylic resin, and 100 parts by weight of a solvent such as butyl carpitol acetate, cal-1~-l-acetate, or terpineol are used. A solution in small portions is used.

The amount used is the total amount of NiB and glass binder (100
The amount is 5 to 70 parts by weight.

Vehicle, NiB powder, and glass binder powder are uniformly mixed using a stirrer such as a Raikai machine or a three-roll stirrer to form a paste. After degassing if necessary, a uniform thin film is formed on the transfer paper using a printing method. Print in a shape. Any general printing method can be used as the printing method, but it is important to have high productivity, the ability to form a long-life film thickness of about 10 to 30 μm, and a highly accurate film thickness control of φ11 (±1 μTrL). Therefore, a screen printing method using a silk screen or the like is particularly preferred.

The thickness of the paste film formed on the transfer sheet (when dry) is 5
~100uTrL1 preferably 15-40μ tiles.

If it is thinner than 5 μm, it is likely to be destroyed by heat stress during energization. On the other hand, if the thickness exceeds 100 μm, smooth transfer to the support will not be possible, and the heat capacity when used as a heat fixing roll will become large, resulting in a long warm-up time.

After drying the paste print on the transfer sheet at room temperature or by heating, a resin liquid is applied to the surface by top coat printing, dried and reinforced, and then cut to match the surface of the support roll core.

Support holiday - Lucoa is a ceramic made of alumina or mullite material, enamel, aluminum whose surface is insulated with inorganic materials, manufactured in the shape of a pipe.
Metal such as stainless steel.

After applying a transfer liquid (water, etc.) to the surface of the support roll core, the above-mentioned transfer paper is wound around this while rotating at 2 yen V to adhere the dry paste and transfer is performed. After peeling off the transfer paper, dry at room temperature or by heating.

Then, it is fired in the atmosphere.

The firing temperature and time vary depending on the type of glass binder used, the film thickness of the transfer paste, etc.
0'C1 Usually, baking is carried out at a temperature of 600 to 700'C for a total of about 10 minutes to 3 hours.

Through this firing process, flammable components such as the vehicle and the transfer liquid are burned, and the NiB in the glass binder is changed to Ni, forming a solid resistance heating layer fused to the surface of the support roll.

[Example] Examples of a heating fixing roll having such a resistance heating layer provided on the surface of the support roll and a fixing device using the roll will be described below with reference to the drawings.

FIG. 1 is a front sectional view of an example of a fixing device equipped with a heated fixed stone roll of the present invention.

This fixing device has a configuration in which a heating roll 1 and a pressure roll 10 are opposed to each other, similar to conventional fixing devices. The heating roll 1 has a diameter of 25# and a length of 2
A resistive heating element layer of the present invention (thickness: 16 μTrL) is applied uniformly over the entire surface on a cylindrical mullite core with a thickness of 1.5M and a thickness of 1.5M.
) and a Teflon (registered trademark) with a thickness of 20μ7n.
It has a release layer 4.

The resistance heating element layer was formed by the following method.

NiB powder (B content 10.5% by weight, average particle size 1μ7r
L>'30% loss Laser powder binder (matched to the coefficient of thermal expansion of the mullite core, average particle size 5μTn) 50% by weight Vehicle consisting of ethyl cellulose and terpineol 20% by weight After uniformly mixing, paste 1~, which was left to stand and defoamed, was printed on transfer sheet 1~ to a film thickness of 24 μm (when dry) using a 200-mesh silk screen.
Dry at room temperature for 10 minutes. Next, this was cut into pieces according to the size of a mullite core, and transferred while rotating around a mullite core coated with an aqueous resin solution, and dried at 100'C for 15 minutes. Then 680 in the air
The temperature was raised to 'C over 25 minutes, kept at that temperature for 10 minutes and fired, and cooled to room temperature for 25 minutes.
/°C) was formed.

Cylindrical electrodes 5.5a are provided on both sides of the ceramic core 2, and the cylindrical electrodes and the heat generating layer are connected by conductive wires 6.
, 6a. The cylindrical electrodes 5, 5a are in contact with sliding bearings 7, 7a that support the heating roll 1, and each of the sliding bearings 7.7a is connected to a conductive wire 8 from a power source.
, 8a are connected.

The frames 15, 158 of the copy are each provided with a bearing housing 16.16a formed of an insulating member,
The above-mentioned slide bearings 7, 7a are supported by the bearing housing. The conductive wires 8 and 8a are connected through holes 17 and 178 formed in the bearing housing, and a driving gear 18 is fixed roughly on the outside of the bearing housing 16, and this gear meshes with a motor side gear 19. heating roll 1
It is designed to rotate.

The pressure roll 10 formed opposite to the heating roll 1 is
As shown in FIG. 2(a), the surface of a metal core 11 is coated with an elastic body 12 (formed of claws, supported by bearing members 13 on both sides, and can rotate freely). The heating roll 1 rotates as the heating roll 1 rotates.

The pressure roll 10 is made of a metal core with a diameter of 15 mm, the surface of which is coated with a silicone sponge to a thickness of 5M, and a spring or the like is used to bring 5 kg of eggs into contact with the heating roll.

Further, as shown in FIG. 2(a), the fixing device has a paper transport path formed by guide plates 24 on both sides of the sandwiching portion between the heating roll 1 and the pressure roll 10, and the paper transport path is The toner image 21 formed on the surface of the paper 20 being conveyed along the path is fixed by applying pressure and heating.

Around the heating roll 1, there is a temperature sensor 22 for temperature control, and a peeling claw 23 for peeling off the copy after fixing.
etc. are provided.

In the heat fixing device having the above configuration, one
When a voltage of 00V was applied, the temperature reached 200°C in about 20 seconds, and the power at that time was about 500W.

[Effect of the invention] In the case of a method using a conventional halogen lamp, 200
900 to 1000 W and a further time of about 5 to 10 minutes were required to obtain the temperature of It was possible to start the system and reduce power consumption by several tens of percent.

Furthermore, after testing 30,000 continuous copies, the output of the heating element decreased by less than 1%, indicating that it has an extremely long life.

Further, by using the heat fixing roll of the present invention, the apparatus can be simplified, the cost can be reduced by 1~, and reliability can be improved at the same time.

Furthermore, the heat generating layer used in the heat fixing roll of the present invention has the advantage that it can be easily formed by screen printing or the like and is excellent in mass production.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing the configuration of an example of a fixing device using the heat fixing roll of the present invention, FIG. 2(a) is a side sectional view, and FIG. 2(b) is the same as that of FIG. FIG. 3 is a perspective view of the heating roll portion, FIG. 3 is a sectional view of a conventional heating roll type fixing device, and FIG. 4 is a process diagram showing the flow of forming the resistance heating layer of the heating fixing roll of the present invention. Symbols in the figure: 1.1a... Heating roll; 2... Ceramic core: 3... Resistance heating element layer; 4... Release layer; 5, 5a
... Cylindrical electrode; 6.6a... Conductor near, 7a...
・1-beam bearing: 8... Conductor; 10, 10a...
・Pressure roll: 11... Metal core; 12... Elastic body; 13.13a... Bearing; 14... Shaft: 15
, 15a... Frame: 16.16a... Bearing housing; 17... Hole; 18... Drive gear;
19... Motor side gear; 20... Heavy paper; 21
... Toner image: 22 ... Temperature sensor; 23.
... Peeling claw; 24... Guide plate; 25... Internal heating element. Figure 2 (a) Figure 2 (b) Figure 3

Claims (1)

[Claims] In a heat fixing roll in which a resistance heating layer is provided around a cylindrical support, a sheet-like material whose main components are a nickel-boron alloy and a glass binder is wound around the outer periphery of the support as the resistance heating layer. A heat fixing roll characterized in that a layer formed by heating and baking after being rotated is used.