KR101592983B1 - exothermic fixing belt and manufacturing method the same - Google Patents

Abstract

The present invention relates to a seamless heat generating fixing belt for use in an image fixing unit of an image forming electronic apparatus such as a copying machine, a printer, a facsimile machine or the like, which comprises a polyimide resin film having a metal resistance heat- And a heat generating layer formed on the heat generating layer.
According to the present invention, heat generated by a metal resistance heating body layer having electrical conductivity and low resistance on the surface of a heating layer is stably maintained, heat resistance is stable in the substrate layer against the heat generation, It is possible to have a stable insulation characteristic such that the current does not flow to the other side.

Description

Exothermic fixing belt and manufacturing method thereof < RTI ID = 0.0 >

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing belt used in image forming electronic devices such as copiers, printers, and facsimiles and having stable heat generation, heat resistance, and insulation characteristics.

The image forming apparatus such as a copying machine, a printer, and a facsimile machine has an image fixing unit. In this image fixing unit, since the solid toner transferred from the intermediate transfer belt to a recording paper such as a copy paper is not stable in an unfixed state, The solid toner is fused to the recording paper by heating at a high temperature to be stabilized, and then pressed to fix the solid toner on the recording paper.

The image fixing unit is composed of a heater, a fixing belt, and a pressing belt. After the heat generated in the heater is transferred to the fixing belt, the fixing belt, which has received the heat, contacts the solid toner on the recording sheet to melt the solid toner. The melted toner is fixed on the recording paper.

In recent years, a fixing belt having a resistance heating body layer containing a heating element has been developed to integrate a heater and a fixing belt so that the fixing belt itself can generate heat. Electricity is supplied to the fixing belt to directly heat the fixing belt Have been developed.

A fixing belt having a resistance heating body layer is proposed in which a conductive material such as carbon powder or metal powder is mixed with a polyimide or silicone rubber or the like.

However, when the temperature of the fixing belt is set to a high temperature of 180 ° C or more, there is a problem that when the carbon powder alone is used as the conductive material, the heat generation temperature does not reach the required level of the fixing belt at 50 ° C.

Also, considering the voltage used in the image forming electronic device, the surface resistance should be 10 Ω / □ or less. For this purpose, the content of the conductive material should be increased to 30 wt% or more, There is a problem that uniform heat generation is difficult to be performed.

Further, in the process of molding the fixing belt, the coating should be applied to the outside of the molding drum. However, since the viscosity of the mixture is very high due to the high content of the conductive material, coating is impossible.

In addition, there is a problem that the elasticity of the fixing belt is lowered due to a high content of the conductive material, the mechanical properties are lowered, and the service life is shortened.

In addition, polyimide, which is a high heat-resistant resin, is used as a material of the fixing belt, and polyimide is not excellent in thermal conductivity and rather acts adiabatically, and thus has a limit to use as a heat fixing belt.

On the other hand, a multilayer fusing belt in which a surface heating element is bonded to a polyimide as an insulating material having heat resistance has been developed. However, such a lamination type fusing belt has a problem in that durability is reduced due to defects on the lamination surface due to lamination by an adhesive.

Korean Patent No. 10-1171741 (entitled " Fever-fixing belt)

Accordingly, the present inventors have conducted studies to solve the above problems, and found that when an ionic metal is added to a polyamic acid solution as a polyimide precursor to form a film for centrifugal molding, the ionic metal Resistance heating element layer is formed on the surface of the reduced and formed film. Thus, the present invention has been completed.

SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide a metal resistance heating body layer which exhibits electrical conductivity and has a low resistance in a stable manner and which has stable heat resistance against the heat generation, And a method of manufacturing the same.

In order to solve the above problems, the present invention provides a seamless heat generating fixing belt for use in an image fixing unit of an image forming electronic apparatus such as a copying machine, a printer, a facsimile machine or the like, comprising: a heat generating layer comprising a polyimide resin There is provided a heat generating fixing belt comprising a structure in which a film layer is laminated on a polyimide film as a base layer.

The present invention also provides a seamless fusing belt for use in an image fixing unit of an image forming electronic apparatus such as a copying machine, a printer, a facsimile machine or the like, comprising: preparing a seamless tubular polyimide film; Preparing a polyamic acid solution; Preparing an ionic metal solution comprising a solvent and an ionic metal-containing material; Adding the ionic metal solution to the polyamic acid solution to prepare an ionic metal-containing polyamic acid solution; Mounting the prepared polyimide film on the outer circumferential surface of a cylindrical forming mold, applying the ionic metal-containing polyamic acid solution onto the outer circumferential surface of the loaded polyimide film, and drying the rotated polyimide film while rotating to form a laminated film layer; And a step of heat-treating the laminated film layer so as to cure the laminated film layer to produce a tubular laminated film which is imidized and has a metal resistance heating body layer formed on the surface thereof.

According to the present invention, since the fixing belt is a polyimide resin film heater that directly generates heat without receiving heat from the heater, it is possible to provide a fixing device that is simple and lightweight compared to the conventional one, It is possible to shorten the waiting time from the time when the image forming apparatus is in a ready state to the image forming apparatus,

According to the present invention, it is possible to form a resistance heating body layer capable of heating at a high temperature of 180 to 250 占 폚, which is a fixing temperature range, in the fixing belt by using only a small amount of metal ion component.

According to the present invention, the resistance heating body layer is uniformly distributed on the surface of the fixing belt, and uniform heat generation is possible.

According to the present invention, in a heat generating fixing belt in which a heat generating layer made of a polyimide resin film having a metal resistance heat generating layer formed on its surface on a base layer made of a heat resistant polyimide resin film is laminated, mechanical properties and heat resistance are expressed by the base layer, The heat applied to the heat generating layer is prevented from flowing to the other side due to the insulating property of the mid resin, so that the heat generating fixing belt can be stably operated.

According to the present invention, the lamination of the substrate layer and the heat generating layer constituting the exothermic fixing belt is easy to be bonded without the need for an adhesive, and the durability is improved because of excellent adhesive strength.

1 is a perspective view of a seamless fixing belt in which a metal resistance heating body layer is formed on an outer surface of a polyimide resin film layer according to an embodiment of the present invention.

The present invention relates to a seamless heat generating fixing belt for use in an image fixing unit of an image forming electronic apparatus such as a copying machine, a printer, a facsimile machine or the like, in which a polyimide resin film layer having a heat- To a heat generating fixing belt having a structure laminated on a polyimide film.

The heating layer of the present invention is characterized in that a solution containing a polyamic acid solution and an ionic metal-containing material and having a controlled viscosity is formed on the surface of the cylindrical molding die And then drying and curing it by rotating it on the outer circumferential surface or the inner circumferential surface to form a resistance heating body layer on the surface of the polyimide resin film layer.

At this time, by setting the surface resistance of the resistance heating body layer formed on the heating layer to be 10 Ω / □ or less, heat can be generated at a temperature of 150 to 250 ° C. by the resistance while flowing electricity by the metal component.

Since the base layer of the present invention should be used as a heat-generating fixing belt that generates heat at a high temperature of 180 ° C or higher, the base layer should be a high heat resistant resin, and a seamless tubular polyimide film may be used.

The fusing belt is required to have rigidity and flexural resistance so that it can operate durably in a high-speed fixing environment, and the elasticity and flexural resistance of the fusing belt may be 3.0 GPa or more and 4,000 times or more, respectively. If the modulus of elasticity is less than 3.0 GPa, the belt is stretched or deformed due to high-speed rotating environment. If the flexing resistance is less than 4,000 times, the image printing apparatus malfunctions or the tubular fusing belt meandering, Defective phenomena such as misalignment can be caused.

The polyimide film of the present invention can satisfy the elastic modulus and bending resistance characteristics as described above.

In addition, polyimide is a thermosetting resin that does not measure the glass transition temperature after curing and has the highest level of heat insulation, insulation and stability among the resin materials, and the heat generated during the operation of the heat fixing belt is transferred So that the electric power applied to the heat fixing belt is prevented from being transmitted to the area other than the resistance heating body layer, so that heat and electric influence are not transmitted to other parts of the apparatus equipped with the heat fixing belt, Lt; / RTI >

The thickness of the exothermic fixing belt of the present invention is preferably 10 to 100 占 퐉 in total of the base layer and the heat generating layer.

In this case, the thickness of the base layer is preferably 5 to 50 mu m. When the thickness is less than 5 mu m, mechanical strength and heat resistance may be deteriorated, and insulation and durability may be deteriorated when electricity is applied. It is difficult to laminate the heat generating layer in the manufacturing process of the invention and it is difficult to handle when the finished heat fixing belt is mounted, and if the thickness exceeds 50 μm, the thickness uniformity may be lowered.

The thickness of the heating layer is preferably 5 to 50 占 퐉. If the thickness is less than 5 占 퐉, adhesion with the base layer may be insufficient and heat resistance and insulation characteristics may be deteriorated. If the thickness exceeds 50 占 퐉, Can be lowered and it is economically undesirable.

Hereinafter, a method of manufacturing the heat generating fixing belt of the present invention will be described in detail.

Polyimide is a thermosetting resin that does not have a glass transition temperature measured after curing and has a heat insulating and insulating property. The polyimide precursor polyamic acid solution is prepared by reacting a diamine and a dianhydride monomer having no soft chain in the molecular structure And then curing it.

In order to produce the exothermic fixing belt of the present invention, a seamless tubular polyimide film is first prepared as a substrate layer.

The polyamic acid solution prepared by reacting one or more diamine monomers with one or more dianhydride monomers in the presence of a solvent is used as a polyimide precursor to prepare a polyamic acid solution. .

The diamine and dianhydride are capable of forming a conventional polyimide precursor, and examples of the diamine include 1,4-phenylenediamine (1,4-PDA), 1,3-phenylenediamine (1,3- PDA), 4,4'-methylene dianiline (MDA), 4,4'-oxydianiline (ODA) and 4,4'-oxyphenylenediamine (OPDA) (PMDA), 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 4,4'-oxy dipyridine Tallic anhydride (ODPA), 4,4'-hexafluoroisopropylidene diphthalic anhydride, and the like can be used.

The solvent may be one or more selected from the group consisting of N-dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide, N-methylpyrrolidone (NMP), gamma-butyrolactone (? -butyrolactone) and the like can be selected and used.

Such a solvent may also be mixed with an aromatic hydrocarbon solvent such as toluene, xylene, and the like.

The solid concentration of the polyamic acid solution to be prepared is preferably 10 to 30% by weight. The viscosity can be controlled to be suitable for coating by the concentration, and good coating and drying can be achieved in the film forming process described below, This can be improved.

Next, the polyamic acid solution and the ionic metal-containing material are mixed and dispersed to prepare an ionic metal-containing polyamic acid solution.

It is preferable that the ionic metal-containing material is at least one selected from the group consisting of a metal compound that can be ionized by a solvent, a metal salt, a metal complex, and a coordination compound capable of reacting with the metal.

At this time, the metal is preferably at least one selected from the group consisting of silver, copper, tin, iron, nickel, aluminum, platinum and gold.

The ionic metal-containing material is dissolved in the polyamic acid solution and is present in a complex state with the carboxyl group of the polyamic acid. The metal ion is reduced and precipitated as nano-sized metal particles in a heat treatment curing process at a high temperature for forming polyimide , The precipitated metal particles are moved to the surface of the film by the centrifugal force due to rotation in the process of forming seamless tubular polyimide film to form a metal layer.

At this time, the formed metal layer has electrical conductivity and a low resistance of 10? /? Or less to allow electricity to flow therethrough while acting as a metal resistance heating element, .

The metal content of the ionic metal-containing material in the ionic metal solution is preferably 10 to 30 parts by weight based on 100 parts by weight of the solid content of the polyamic acid solution. If the metal content of the ionic metal-containing material exceeds 30 parts by weight When the amount is less than 10 parts by weight, the resistance increases, the surface resistance becomes uneven, and uniform heat generation becomes difficult. Thus, the electrical properties are lowered and the heat generation efficiency is reduced. Can not do it.

The viscosity of the polyamic acid solution is preferably in the range of 50 to 1,000 poise, and the final viscosity of the ionic metal-containing polyamic acid solution mixed with the solvent, polyamic acid, and ionic metal- It is also desirable to be poised.

If the viscosity is less than 50 poise, the uniformity of the thickness of the formed film layer is decreased. If the porosity exceeds 600 poise, the bubble of the raw material itself is not defoamed and the yield is decreased. The wetting and spreading properties deteriorate, and the processability is decreased, which is undesirable.

Next, in order to form a laminate structure, the prepared seamless tubular polyimide film was mounted on the outer circumferential surface of a cylindrical forming mold, and the ionic metal containing polyamic acid solution was applied on the outer circumferential surface of the mounted polyimide film and rotated Dried and cured to form a laminated film layer.

The formed film layer can be easily bonded to the polyimide film without an adhesive in the process of forming the film layer, and the durability can be improved due to the excellent adhesive force.

At this time, in the method of applying the ionic metal-containing polyamic acid solution on the outer circumferential surface, a mold having a polyimide film clogged with the inside of a cylinder is immersed in a container containing the ionic metal-containing polyamic acid solution and taken out, May be applied directly to the outer circumferential surface of the mounted molding die.

The ionic metal-containing polyamic acid solution is applied to the outer circumferential surface of the polyimide film, and the cylindrical mold is rotated to increase the temperature and heat treatment to volatilize the solvent to progress the imidization to heat-settle the seamless tubular laminated film A belt can be manufactured.

At this time, the heat treatment is performed stepwise at 60 to 400 ° C. First, prebaking is performed at 60 to 80 ° C for 5 to 100 minutes to remove the solvent and moisture remaining on the surface. Then, the temperature was raised from 1 to 10 ° C. per minute, and the temperature was raised to a maximum temperature of 250 to 400 ° C., followed by keeping for 10 minutes to 3 hours. Finally, post-curing was performed to completely remove the solvent and moisture present on the surface, And the fixing belt on the solidified film can be manufactured at the same time.

The number of revolutions of the cylindrical shaping mold is preferably 50 to 1,000 rpm, and it is preferable that the film layer to be formed and the metal layer formed on the surface of the film layer are uniform. If the number of revolutions is less than 50 rpm, The flow of the particles becomes small and the formation of the metal layer becomes nonuniform. When it exceeds 1,000 rpm, the curing becomes uneven, the thickness and the density of the metal layer increase, and the mechanical strength of the formed film layer may be lowered.

The thickness of the exothermic fixing belt manufactured by the present invention is preferably 10 to 100 占 퐉. If the thickness is less than 10 占 퐉, handling of the fixing belt is difficult to handle, mechanical strength and heat resistance may be deteriorated, Durability may be lowered. If it exceeds 100 m, it is undesirable because the metal layer is unevenly formed and the thickness uniformity is lowered.

Hereinafter, the present invention will be described in detail with reference to Examples. It is to be understood, however, that these examples are for illustrative purposes only and are not to be construed as limiting the scope of the invention as defined by the appended claims. And will be apparent to those skilled in the art to which the present invention pertains.

[Example 1]

A seamless tubular polyimide film having a thickness of 30 占 퐉 was prepared as a base layer.

A reactor equipped with a mechanical stirrer, a reflux condenser and a nitrogen inlet was charged with 1,093 g of DMF as a solvent, and the temperature of the reactor was set to 25 ° C. 100.12 g (0.5 mol) of ODA was added thereto and stirred for 1 hour. After confirming that it was completely dissolved, 73.56 g (0.25 mol) of BPDA was added, and the temperature of the solution was kept at 25 캜. Then, 54.53 g (0.25 mol) of PMDA was added to obtain a polyamic acid solution having a solid content of 16.6 wt% (219.21 g excluding 9 g of water resulting from polymerization of monomers).

A reactor equipped with a nitrogen inlet was charged with 100 g of solvent DMF, and the temperature of the reactor was set to 25 ° C. 43.4 g (0.26 mol) of silver acetate (27.9 g in silver content, 13 parts by weight based on 100 parts by weight of solid content of the obtained polyamic acid solution) and 1,1,1-trifluoro-2,4- pentadione (TFAH) (0.31 mol, 1.2 eq.) was dissolved in tetrahydrofuran to prepare an ionic metal solution.

The ionic metal solution prepared above was added to the polyamic acid solution in a nitrogen atmosphere at 25 캜 to prepare an ionic metal-containing polyamic acid solution

At this time, the prepared ionic metal-containing polyamic acid solution was in a uniform state and had a viscosity of 150 poise.

Thereafter, the prepared polyimide film was attached to the outer surface of the cylindrical stainless-steel molding die, and the prepared ionic metal-containing polyamic acid solution was coated on the outer peripheral surface of the polyimide film using a dispenser while rotating the molding mold at a speed of 100 rpm The coating solution was applied at a discharge rate of 3 g / 10 seconds and pre-baked at a temperature of 80 ° C to remove the solvent and moisture remaining on the surface. The temperature was maintained at 5 ° C per minute C to obtain a heat-fusing belt of a seamless tubular laminated film in which the residual solvent and moisture remaining on the surface and inside thereof were completely removed and imidized, and the total thickness of the manufactured belt Was 65 m.

[Example 2]

A heat generating fixing belt of a tubular film was produced in the same manner as in Example 1, except that 57.42 g of Silver Trifluoroacetate was used instead of acetic acid in Example 1 and no ligand was used.

[Example 3]

A heat generating fixing belt of a tubular film was produced in the same manner as in Example 1, except that 15.95 g of copper acetate was used instead of acetic acid in Example 1.

[Example 4]

Except that 33.1 g of 1,1,1,5,5,5,5-hexafluoropentadione (HFAH) was used as the ligand reacting with silver acetate in Example 1, and the exothermic fixation of the tubular film Belt.

[Example 5]

A heat generating fixing belt of a tubular film was produced in the same manner as in Example 1, except that 46.23 g of Tin Acetate was used instead of acetic acid in Example 1.

[Comparative Example 1]

A heat generating fixing belt of a tubular film was produced in the same manner as in Example 1, except that 13.4 g of silver acetate and 12.1 g of TFAH were used in Example 1.

[Comparative Example 2]

In Example 1, 14.9 g of carbon black was used instead of acetic acid in the preparation of the ionic metal solution, and 14.9 g of polyvinyl pyrolidone (PVP), which is a carbon black dispersant, was used instead of the ligand. A heat generating fixing belt of a tubular film was produced using the same method as in Example 1.

[Comparative Example 3]

A heat generating fixing belt of a tubular film was produced in the same manner as in Comparative Example 1, except that 44.61 g of carbon black and 44.6 g of PVP were used in Comparative Example 1.

[Comparative Example 4]

Except that the film layer was formed by applying the ionic metal-containing polyamic acid solution in a state in which the forming mold was not rotated in Example 1, the heat-fusing belt of the tubular film .

[Comparative Example 5]

A heat generating fixing belt of a tubular film was produced in the same manner as in Example 1, except that the belt produced in Example 1 had a thickness of 9 占 퐉 (base layer: 4 占 퐉, heat generating layer: 5 占 퐉).

The heat-fusing belt manufactured in the above Examples and Comparative Examples were evaluated for physical properties by the following methods.

(1) Surface resistance

The surface resistance was measured using a Hiresta-UP MCT-HT450 (Mitsuibishi Chemical Corporation) (measuring range: 10 × 10 ⁵ to 10 × 10 ¹⁵ Ω) and a low resistance meter (CMT-SR 2000N -Point Probe System, measuring range: 10 x 10 ^-3 to 10 x 10 ⁵ Ω).

(2) Heating temperature

The temperature was measured at the surface of the exothermic fixing belt of the tubular film using a thermotracer TH1101 (manufactured by Nippon Electric Sampling Co., Ltd.).

(3) Difference in belt surface temperature distribution

Using a thermotracer TH101 (manufactured by Nippon Electric Glass Co., Ltd.), the temperature is measured at 10 positions while moving in the longitudinal direction of the fixing belt of the tubular film, and the difference between the maximum value and the minimum value of the measured temperature is obtained.

(4) Modulus of elasticity

The measurement was conducted in accordance with JIS K6301 using an Instron universal testing machine (model 1000) (measurement conditions: 1 kN, measurement at a speed of 50 mm / min, measurement environment: 25 ° C, 55 RH%).

(5) Flexibility

The fracture tester was used to measure the number of fractures according to IPC-TM-650, 2.4.3 (R = 1.25 mm, Stroke = 25 mm) method.

Surface resistance
(Ω / □) Heating temperature
(° C) Difference in belt surface temperature distribution (℃) Modulus of elasticity
(GPa) Flexibility
(time) film
thickness
Deviation (탆) Fixability
(%) Example 1 2.3 230 7 3.86 8,526 ± 3.6 99 Example 2 8.2 180 9 3.46 8,480 ± 4.1 99 Example 3 2.8 210 5 3.88 8,652 ± 3.3 99 Example 4 1.9 250 6 3.71 8,472 ± 2.9 99 Example 5 5.7 220 10 3.62 8,777 ± 5.1 99 Comparative Example 1 4.3 x 10 ¹³ 23 0 3.72 8,672 ± 4.0 0 Comparative Example 2 2.6 x 10 ¹¹ 25 0 4.71 8,260 ± 4.1 0 Comparative Example 3 3.7 x 10 ⁴ 52 5 3.72 120 ± 7.1 10 Comparative Example 4 3.4 235 42 3.77 8,342 ± 25.2 91 Comparative Example 5 5.1 225 5 2.80 3.124 ± 4.1 98

From the above Table 1, it can be seen that the exothermic fixing belt according to the comparative example has lowered physical properties in some items of the test evaluation, but the exothermic fixing belt according to the embodiment is excellent in the items before the test evaluation and can be used as a heat fixing belt.

1: metal resistance heating layer, 2: polyimide resin film layer, 3: polyimide film base layer

Claims (10)

BACKGROUND ART [0002] In a seamless heating fusing belt used in an image fixing unit of an image forming electronic apparatus such as a copying machine, a printer, a facsimile,
And a polyimide resin film layer having a metal resistance heat generating layer formed on its surface as a heat generating layer is laminated on a polyimide film as a base layer,
The metal resistance heater layer in the heating layer is formed by rotational molding and heat treatment of a polyamic acid solution containing an ionic metal consisting of a metal compound that can be ionized by a solvent and a coordination compound capable of reacting with the metal A heat-setting belt. The method according to claim 1,
And the surface resistance of the heat generating layer is 10? /? Or less. The method according to claim 1,
Wherein the exothermic layer has an exothermic temperature of 150 to 250 ° C. The method according to claim 1,
Wherein the heat generating layer has a thickness of 5 to 50 占 퐉 and the base layer has a thickness of 5 to 50 占 퐉. In a seamless fusing belt used in an image fixing unit of an image forming electronic apparatus such as a copying machine, a printer, a facsimile machine or the like,
Preparing a seamless tubular polyimide film;
Preparing a polyamic acid solution;
Preparing an ionic metal solution comprising a solvent and an ionic metal-containing material;
Adding the ionic metal solution to the polyamic acid solution to prepare an ionic metal-containing polyamic acid solution;
Mounting the prepared polyimide film on the outer circumferential surface of a cylindrical forming mold, applying the ionic metal-containing polyamic acid solution onto the outer circumferential surface of the loaded polyimide film, and drying the rotated polyimide film while rotating to form a laminated film layer; And
Heat-treating the laminated film layer so as to cure the laminated film layer to prepare a tubular laminated film which is imidized and has a metal-resistant heating element layer formed on its surface,
Wherein the ionic metal-containing material is a metal compound that can be ionized by a solvent and a coordination compound capable of reacting with the metal,
Wherein the metal is at least one selected from the group consisting of silver, copper, tin, iron, nickel, aluminum, platinum and gold,
The coordination compound is preferably 1,1,1-trifluoro-2,4-pentadione (TFAH) or 1,1,1,5,5,5- (1, 1, 1, 5, 5, 5-hexafluoropentadione, HFAH). delete delete 6. The method of claim 5,
Wherein the content of the metal in the ionic metal solution is 10 to 30 parts by weight based on 100 parts by weight of the solid content of the polyamic acid solution. 6. The method of claim 5,
Wherein the ionic metal-containing polyamic acid solution has a viscosity of 50 to 600 poise. 6. The method of claim 5,
Wherein the rotation number of rotation of the cylindrical forming mold is 50 to 1,000 rpm.

Images