JPH05163360A - Composite tube - Google Patents

Abstract

PURPOSE:To obtain a composite tube nonproblematic in slip or poor fixing occurring in an image formation apparatus by the belt fixing method because the polyimide resin fixing belt is insufficient in slidability and is apt to form a powder of abrasion due to the friction of drive. CONSTITUTION:A single-layer tube wherein a fluororesin powder is dispersed in the polyimide tubular layer or a double-layer tube formed by forming an external tubular layer made of a fluororesin around the external periphery of an internal tubular layer made of a polyimide resin containing a fluororesin powder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a copying machine, a facsimile,
The present invention relates to a composite tubular article suitable for a fixing belt of an image forming apparatus such as a printer.

[0002]

2. Description of the Related Art Conventionally, as a method for fixing an image on a transfer sheet in an image forming apparatus, there is, for example, a heat roller fixing method. In this roller fixing method, for example, as shown in FIG. 1, a heat roller 1 and a press roller 2 are vertically opposed to each other,
It is a method of feeding the transfer paper 3 between the rollers 1 and 2,
The heat-sensitive ink 5 temporarily attached to the transfer paper 3 is melted and fixed by the heat generated by the heater 4 built in the heat roller 1, and is pressed by the press roller 2 to strengthen the fixing.
As a result, the image 6 made of the thermal ink is formed on the transfer paper 3. In this case, in order to prevent the heat-sensitive ink from adhering to the surface of the heat roller, it is common to coat the roller surface with a fluororesin or impregnate this coating layer with silicone oil.

By the way, when the heat-sensitive ink is fused and fixed to the transfer paper by the roller fixing method, the surface temperature of the heat roller needs to be equal to or higher than the heat-melting temperature of the heat-sensitive ink. Therefore, as long as the roller fixing method is used, it is necessary to wait until the surface temperature of the heat roller reaches the melting temperature of the heat-sensitive ink at each fixing operation, which is inefficient (this waiting time is usually 20 seconds to 10 minutes). is there).

Therefore, in order to reduce the waiting time, a method using a fixing belt has been proposed. In this belt fixing method, as shown in FIG. 2, a fixing belt 10 is driven around two rollers 7 and 8 and a heater 9 which are separated from each other, and the press roller 2 is arranged so as to face the heater 9. The transfer paper 3 on which the heat-sensitive ink 5 is temporarily attached is fed between the belt 10 and the press roller 2 to melt and fix the heat-sensitive ink 5 on the transfer paper 3 to form an image 6
Is formed. According to this method, since the belt is thin and has a small heat capacity, the fixing work can be immediately performed by the heat generated by the heater, and the waiting time becomes extremely short, which is preferable.

A belt used for such a belt fixing method is a tubular material made of a polyimide resin having excellent heat resistance and mechanical strength, or an inner layer made of a polyimide resin and an outer layer made of a fluororesin formed on the outer peripheral surface of the inner layer. A composite tubular article (JP-A-3-130149) is known.

[0006]

When the above-mentioned polyimide resin tubular article or composite tubular article is used as a fixing belt, it is natural that the polyimide resin layer comes into contact with the rollers 7 and 8 and the heater 9. The polyimide resin layer does not have sufficient wear resistance, and abrasion powder is likely to be generated due to friction with the heater 9, which is often coated with glass. The fact that abrasion powder is easily generated means that the sliding characteristics of the fixing belt are insufficient. For example, if the abrasion powder adheres to the surfaces of the rollers 7 and 8 and the heater 9, the fixing belt may slip, or heat transfer may be hindered to cause defective fixing (or unfixable).

[0007]

As a result of earnest research for solving the above problems of the prior art, the present inventor has found that sliding properties can be improved by containing and dispersing fluororesin powder in the polyimide resin layer. The present invention has been completed.

That is, the composite tubular article according to the present invention is characterized by comprising a polyimide resin tubular layer in which fluororesin powder is dispersed.

The fluororesin dispersedly contained in the polyimide resin tubular layer in the composite tubular article according to the present invention is not particularly limited, and polytetrafluoroethylene (PTF) may be used.
E), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethyne-perfluoroalkyl vinyl ether copolymer (PFA),
Ethylene-tetrafluoro-ethylene copolymer (ETF
E), polychlorotrifluoroethylene (PCTFE)
Etc. can be used.

These fluororesin powders can be used in any shape such as spherical, scaly or amorphous, but it has been found that the particle size is preferably 10 μm or less from the viewpoint of dispersibility in the polyimide resin tubular layer. is doing. In addition, the amount of the fluororesin powder dispersed in the polyimide resin layer is 0.1 to 20 with respect to 100 parts by weight of the polyimide resin in order to maintain the mechanical strength of the composite tubular product and improve the sliding characteristics.
It has also been found suitable to use parts by weight.

Next, a method for manufacturing the composite tubular article according to the present invention will be described. This composite tubular material is, for example, a polyamic acid (precursor of polyimide resin) solution in which fluororesin powder is dispersed is applied to the inner peripheral surface of a heat-resistant cylinder made of metal, glass, or the like, and then heated to produce polyamic acid. It can be obtained by a method in which a polyimide tubular product in which fluororesin powder is dispersed and contained is formed by converting the imide and removing the solvent by evaporation, and thereafter the tubular product is peeled from the heat resistant cylinder.

The polyamic acid solution used in the above method can be obtained by reacting tetracarboxylic dianhydride or its derivative with approximately equimolar amounts of diamine in an organic polar solvent.

This tetracarboxylic dianhydride is represented by the following chemical formula 1.
Indicated by.

[0014]

[Chemical 1]

Specific examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ',
4,4'-benzophenone tetracarboxylic acid dianhydride,
3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) propane Dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, perylene-3,
4,9,10-tetracarboxylic dianhydride, bis (3,3
4-dicarboxyphenyl) ether dianhydride, ethylene tetracarboxylic acid dianhydride and the like can be mentioned.

Specific examples of the diamine to be reacted with such a tetracarboxylic dianhydride include 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'diamiodiphenylmethane,
3,3'-diaminodiphenylmethane, 3,3'-dichlorobenzidine, 4,4'-aminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 1,5-
Diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3'-dimethyl-4,4'-diaminobiphenyl, benzidine, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 4,4 '
-Diaminophenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenylpropane, 2,4-bis (β-amino-t-butyl) toluene, bis (p-β-amino-t-butyl) Phenyl) ether, bis (p-β-methyl-δ-aminophenyl) benzene, bis-p- (1,1-dimethyl-5-aminopentyl) benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di (p-aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine,
Decamethylenediamine, diaminopropyltetramethylenediamine, 3-methylheptamethylenediamine, 4,
4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1,2-bis- (3-aminopropoxy) ethane, 2,2-dimethylpropylenediamine, 3
-Methoxyhexamethylenediamine, 2,5-dimethylhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 5
-Methylnonamethylenediamine, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,
10-diamino-1,10-dimethyldecane, 1,12
-Diaminooctadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, piperazine, H
₂ N (CH ₂ ) ₃ O (CH ₂ ) ₂ O (CH ₂ ) NH ₂ ,
H ₂ N (CH ₂ ) ₃ S (CH ₂ ) ₃ NH ₂ , H ₂ N (C
_{H 2) 3 N (CH 3} ) (CH 2) 3 NH 3 and the like.

Further, as a preferable example of the organic polar solvent used when the tetracarboxylic dianhydride and the diamine are reacted, N, N-dialkylamides such as N, N-dimethylformamide and N, N-dimethylacetamide are used. Can be mentioned. These can be easily removed from the polyamic acid solution by evaporation, substitution, diffusion or the like. Further, polar solvents other than the above, for example, N, N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-methyl-2-pyrrolidone, pyridine , Dimethyl sulfone, tetramethylene sulfone, dimethyl tetramethylene sulfone, etc. may be used, and these organic polar solvents may be used alone or in combination of two or more kinds.

In addition, these organic polar solvents include cresol,
It is also possible to mix one or more of phenols such as phenol and xylenol, benzonitrile, dioxane, hexane, benzene and toluene. However, addition of water should be avoided in order to prevent lowering of the molecular weight due to hydrolysis of the polyamic acid formed.

A polyamic acid solution is obtained by reacting the above tetracarboxylic dianhydride and diamine in an organic polar solvent for about 0.5 to 10 hours. The monomer concentration during the reaction can be set according to various factors, but is usually about 5 to 30% by weight. The reaction temperature is 80 ° C.
It is preferable to set the temperature below (more preferably 5 to 50 ° C.).

When the tetracarboxylic dianhydride and the diamine are reacted in the organic polar solvent in this manner, the solution viscosity increases with the progress thereof. In the present invention, however, the logarithmic viscosity [η] is 0.5 or more. Preference is given to using polyamic acids. The tubular body made of a polyimide resin, which is formed by using a polyamic acid having a logarithmic viscosity [η] of 0.5 or more, has an advantage of being particularly excellent in heat resistance. The logarithmic viscosity is a value calculated by the following mathematical formula 1 by measuring the drop time of the polyamic acid solution and the solvent using a capillary viscometer.

[0021]

[Equation 1]

If the fluororesin powder is added to the reaction system, a fluororesin powder-containing polyamic acid solution can be obtained at the end of the reaction. Of course, after completion of the reaction, fluororesin powder may be added to the polyamic acid solution and mixed uniformly.

In order to obtain a composite tubular article by the above method, first, a polyamic acid solution containing fluororesin powder is applied to the inner peripheral surface of the heat resistant cylinder. Application of the fluororesin powder-containing polyamic acid solution to the inner peripheral surface of the cylinder is performed by immersing the cylinder in the solution and pulling it up, supplying the solution into one end of the cylinder, and then traveling in a bullet shape, a spherical shape, or the like in the cylinder. It can be performed by a method of running the body, a method of spray-coating the solution in a cylinder, or the like.

The viscosity of the polyamic acid solution when the fluororesin powder-containing polyamic acid solution is applied to the inner peripheral surface of the heat-resistant cylinder by these methods has a viscosity of about 10 to 10 from the viewpoint of workability.
It is preferably set to 10,000 poise (temperature at the time of coating operation, measured value by a B-type viscometer). The cylinder used here has an inner diameter substantially equal to the outer diameter of the target composite tubular article. Since the fixing belt of the image forming apparatus usually has an outer diameter of about 10 to 500 mm, a cylinder having an inner diameter substantially equal to that of the cylinder can be used. Then, in order to improve the appearance of the composite tubular product, it is preferable that the surface roughness (Rz) of the inner peripheral surface of the cylinder is about 1 to 10 μm.

As the traveling body, for example, those made of metal, solvent-insoluble plastic, or glass can be used. The traveling is performed by a method of pushing the traveling body by compressed air, gas explosion, etc., a method of towing by a towing wire, a decompression method or a self-weight traveling method. Whichever method is used for this running, it is preferable to keep the cylinder vertical or horizontal in order to make the coating thickness uniform, and it is also possible to rotate the cylinder and the running body.

Thus, after coating the fluororesin-containing polyamic acid solution on the inner peripheral surface of the heat-resistant cylinder, it is heated to convert the polyamic acid into an imide and remove the solvent to form a composite tubular article. The heating temperature can be appropriately set, but first, the ring-closing water and the solvent generated during the imide conversion are removed by evaporation by heating at a low temperature of about 80 to 180 ° C, and then the temperature is raised to about 250 to 400 ° C to convert the imide. It is preferable to employ a multi-step heating method that terminates. The time required for heating is set according to the heating temperature, etc., but usually, it is about 20 to 60 for both low temperature heating and high temperature heating thereafter.
Minutes. By adopting such a multi-step heating method, it is possible to prevent the generation of minute voids in the composite tubular product due to the evaporation of the ring-closing water and the solvent that accompany the imide conversion.

After the polyimide resin composite tubular product is formed on the inner peripheral surface of the heat-resistant cylinder in this manner, the tubular product is peeled off from the inner peripheral surface of the cylinder. The peeling operation can be performed by, for example, previously providing a small through hole in the wall of the cylinder and sending air under pressure to this hole.

The above method uses a polyamic acid solution, but since an organic solvent-soluble polyimide resin is already known, a polyimide composite tubular product can be obtained using this polyimide resin solution. If a polyimide resin solution is used, the imide conversion is naturally unnecessary.

The composite tubular article according to the present invention may consist of only the above-mentioned fluororesin powder-containing polyimide resin tubular layer, but PTFE and FE may be further formed on the layer.
A multi-layer structure having a fluororesin tubular outer layer made of P, PFA, ETFE, PCTFE, or the like can also be used. Such a multi-layer structure product is preferable because it has a more excellent offset property when used as a fixing belt of an image forming apparatus and is less likely to cause paper jam. The thickness of the inner layer and the outer layer of the composite tubular article can be set as appropriate,
Usually, the former is about 10-150 μm and the latter is about 1-20 μm.
m.

This multilayer structure has, for example, a fluororesin tubular material formed on the inner peripheral surface of a heat-resistant cylinder, and then the same fluororesin-containing polyamic acid as described above is formed on the inner peripheral surface of the fluororesin tubular material. A solution is applied, and then heated to convert the polyamic acid into an imide and remove the solvent to integrally form a fluororesin powder-containing polyimide resin tubular product,
After that, it can be obtained by a method of peeling from the inner peripheral surface of the cylinder.

In order to form a fluororesin tubular product on the inner surface of the heat-resistant cylinder, a dispersion containing fluororesin powder in a concentration of about 5 to 80% by weight is applied to the inner surface of the cylinder, and then dispersed by heating. A method of evaporating and removing the medium and sintering (sintering) the fluororesin can be adopted.
This fluororesin dispersion may be added with a surfactant or a thickening agent in order to improve the coating property on the inner peripheral surface of the cylinder. The dispersion medium of the fluororesin dispersion is often water, and therefore heating is about 80
It is preferable to use a multi-step heating method in which water is evaporated and removed at ˜180 ° C., and then heating is performed to a temperature equal to or higher than the melting point of the fluororesin and sintering is performed.

In this multi-layer structure product, a fluororesin dispersion is applied to the outer peripheral surface of a polyimide resin composite tubular product containing a fluororesin powder, and then heated to evaporate and remove the dispersion medium in the dispersion and to remove fluorine. It can also be obtained by a method of sintering a resin.
The fluororesin powder-containing polyimide resin composite tubular article is coated with a fluororesin dispersion on the outer peripheral surface by a method of immersing the tubular article in the fluororesin dispersion and pulling it up, or by spraying the fluoroplastic dispersion on the outer peripheral surface of the tubular article. It can be performed by the method of doing. When applying the fluororesin dispersion by the dipping method,
The fluororesin dispersion will also be applied to the inner peripheral surface of the composite tubular material, but in this case, prior to heating,
The inner peripheral surface of the tubular article is wiped to remove the fluororesin dispersion adhering to the inner peripheral surface.

In order to improve the adhesive strength between the fluororesin tubular outer layer and the fluororesin-powder-containing polyimide resin tubular inner layer in the production of such a multi-layer structure article, at least one surface is subjected to a known adhesion treatment, for example, Alkali metal treatment, primer coating treatment, ultrasonic treatment, sputter etching treatment, plasma treatment, corona discharge treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, laser treatment and the like can be performed.

Further, in the multilayer structure product of the present invention, powder such as silicon dioxide, glass beads, crosslinked silicone resin, ceramics, polyimide resin and benzoguanamine resin is dispersed in the fluororesin tubular outer layer to improve abrasion resistance. It is also possible to disperse a conductive powder of carbon, graphite, metal or the like in the outer layer to impart conductivity and prevent adhesion of dust, dust and the like. Considering dispersibility with the fluororesin, it is preferable that the particle size of these powders be about 5 μm or less,
From the viewpoint of mechanical strength, the amount of addition is usually 1
It is preferably 0.5 to 50 parts by weight with respect to 00 parts by weight.

[0035]

The present invention will be described in more detail with reference to the following examples. In the examples and comparative examples, 3,3 ′,
4,4'-biphenyltetracarboxylic dianhydride is "B
PDA "and pyromellitic dianhydride is" PMDA "
And p-phenylenediamine is "PDA", 3,3 '
-Diaminodiphenyl ether is abbreviated as "DDE" and N-methyl-2-pyrrolidone is abbreviated as "NMP".

Example 1 Equal moles of PMDA and DDE were dissolved in NMP in a flask (monomer concentration 20% by weight) and reacted in a nitrogen gas atmosphere at a temperature of 20 ° C. for 5 hours while stirring to give a polyamic acid solution. obtain. The polyamic acid solution had a rotational viscosity of 29000 poise and a logarithmic viscosity [η] of 3.4. The rotational viscosity is a value measured with a B-type viscometer at a temperature of 20 ° C.

Next, this polyamic acid solution was heated to 50 ° C., and PTFE powder having an average particle size of 3.5 μm was added to this solution at a ratio of 3 parts by weight to 100 parts by weight of the polyamic acid. Stir to evenly disperse. Then, filtration is performed using a # 400 stainless mesh to obtain a fluororesin powder-containing polyamic acid solution.

On the other hand, separately from this, the PFA concentration is 60% by weight.
Water-based dispersion (manufactured by DuPont, trade name TE-
334J) and an aqueous dispersion having a carbon black concentration of 16.5% by weight (manufactured by Lion Corporation, trade name W-311).
By mixing N), a mixed dispersion containing PFA and carbon black is obtained. The ratio of PFA and carbon black in this mixed dispersion was 4 parts by weight of carbon black with respect to 100 parts by weight of PFA.

Inner diameter 50 mm, wall thickness 5 mm, length 500 m
m, the surface roughness (Rz) of the inner peripheral surface was adjusted to 2 μm, and a stainless steel cylinder (cylindrical body) was immersed in the polyamic acid solution containing the fluororesin powder and pulled up, and then the cylinder was held vertically. A bullet-shaped running body having an outer diameter of 49.4 mm is moved down by its own weight, so that the fluororesin powder-containing polyamic acid solution is uniformly applied to the inner peripheral surface of the cylinder.

This is heated at a temperature of 70 ° C. for 60 minutes, the temperature is raised to 300 ° C. and further heated for 60 minutes to evaporate and remove the solvent and the ring-closing water and convert the imide to form a fluororesin powder-containing polyimide resin tubular product. Then, air is pressure-fed from a small through-hole provided in advance at one end of the cylinder to separate the tubular object from the inner peripheral surface of the cylinder. This tubular product had a length of about 500 mm, an outer diameter of 50 mm, and a thickness of 30 μm.

The fluororesin powder-containing polyimide resin tubular product is immersed in the mixed dispersion, pulled up, air-dried for 10 minutes, and the inner peripheral surface thereof is wiped off with a waste cloth.
Then, by heating at 100 ° C. for 10 minutes to evaporate and remove water as a dispersion medium, and further heating at 400 ° C. for 5 minutes, PFA sintered on the outer peripheral surface of the fluororesin powder-containing polyimide resin tubular inner layer A tubular product having a multi-layered structure with a tubular outer layer formed was obtained. The PFA tubular outer layer had a thickness of 8 μm, a surface roughness Rz of 3.2 μm, and a surface resistance of 9 × 10 ⁴ Ω / □.

When this tubular product was cut into a width of 300 mm and used as a fixing belt (endless belt) of an image fixing device, a system having a good offset property was obtained, and the obtained image had a uniform silk grain. It had a textured surface. In addition, when a continuous paper passing test was conducted on this device,
There was no problem even with 100,000 sheets.

Example 2 BPDA and PDA were used in place of PMDA and DDE to obtain a rotational viscosity of 34000 poise and a logarithmic viscosity [η] .2.
9 to obtain a polyamic acid solution, and a PTFE powder to be added to the polyamic acid solution has an average particle diameter of 3.0 μm.
A fluororesin-containing polyimide resin tubular product is obtained in the same manner as in Example 1 except that the ratio is 4 parts by weight with respect to 100 parts by weight of polyamic acid.

The same mixed dispersion as used in Example 1 was spray-coated on the outer peripheral surface of this fluororesin-containing polyimide resin tubular material using an air spray gun, and 10
After air-drying for 10 minutes, heat at 100 ℃ for 10 minutes, then 400
A sintered PTFE outer tubular layer is formed by heating at 0 ° C for 10 minutes. In the obtained tubular product having a multilayer structure, the thickness of the PFA tubular outer layer is 8 μm and the surface roughness R is
z was 3.7 μm, and surface resistance was 1 × 10 ⁵ Ω / □.

When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1, the offset property was good, and the obtained image also had a uniform silky surface. In the continuous paper feeding test, no trouble occurred even after 100,000 sheets.

Example 3 Example 1 The same cylinder and mixed dispersion were prepared, the cylinder was immersed in the mixed dispersion and pulled up, heated at 100 ° C. for 60 minutes, further heated to 400 ° C. and heated for 5 minutes. By doing so, a fluororesin tubular product is formed on the inner peripheral surface of the cylinder.

Next, this cylinder is immersed in the same polyamic acid solution containing PTFE powder as that used in Example 2 and pulled up. Then, while holding this cylinder vertically, the bullet-shaped traveling body is driven by its own weight, heated at 70 ° C., and heated at 300 ° C.
A multilayer structure composed of a fluororesin powder-containing polyimide resin tubular inner layer (thickness 30 μm) and a sintered PFA tubular outer layer was obtained by performing heating at 0 ° C. and peeling from the cylinder in the same manner as in Example 1. A tubular product having the above was obtained. The tubular outer layer of the tubular article has a thickness of 8 μm and a surface roughness Rz.
Was 1.9 μm and the surface resistance was 8 × 10 ⁴ Ω / □.

When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1, the offset property was good, and the obtained image also had a uniform silky surface. In the continuous paper feeding test, no trouble occurred even after 100,000 sheets.

Example 4 The same procedure as in Example 1 was repeated except that the same fluororesin-containing polyamic acid solution as in Example 2 was used, and a fluororesin powder-containing polyimide resin tubular inner layer and a sintered PFA tubular outer layer were used. A tubular product having a multi-layered structure was obtained. The tubular outer layer of the tubular article had a thickness of 8 μm, a surface roughness Rz of 3.4 μm, and a surface resistance of 2 × 10 ⁵ Ω / □.

When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1, the offset property was good, and the obtained image also had a uniform silky surface. In the continuous paper feeding test, no trouble occurred even after 100,000 sheets.

Example 5 Instead of the polyamic acid obtained from BPDE and PDA, P
Using a polyamic acid solution obtained from MDA and DDE (the same as used in Example 1), and PTF
Fluorine was prepared in the same manner as in Example 2 except that PFA powder having an average particle diameter of 3.2 μm was mixed in place of E powder in an amount of 3.5 parts by weight with respect to 100 parts by weight of polyamic acid. A tubular product having a multi-layer structure composed of a resin powder-containing polyimide resin tubular inner layer and a sintered PFA tubular outer layer was obtained. The tubular outer layer made of PFA in the tubular article had a thickness of 8 μm, a surface roughness Rz of 4.0 μm, and a surface resistance of 1 × 10 ⁵ Ω / □.

When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1, the offset property was good, and the obtained image also had a uniform silky surface. In the continuous paper feeding test, no trouble occurred even after 100,000 sheets.

Example 6 The same as Example 3 except that PFA powder having an average particle size of 3.2 μm was added and mixed at a ratio of 3.5 parts by weight to 100 parts by weight of polyamic acid instead of the PTFE powder. By carrying out the work described above, a tubular product having a multi-layer structure composed of a fluororesin powder-containing polyimide resin tubular inner layer and a sintered PFA tubular outer layer was obtained. The thickness of the tubular layer is 8μ
m, surface roughness Rz is 2.0 μm, and surface resistance is 7 × 10 ^4.
It was Ω / □.

When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1, the offset property was good, and the obtained image also had a uniform silky surface. In the continuous paper feeding test, no trouble occurred even after 100,000 sheets.

Example 7 A tubular article having a multi-layer structure was prepared in the same manner as in Example 1 except that a mixed dispersion of silica powder and PFA was used instead of the mixed dispersion of carbon black and PFA. Obtained. The mixing dispersion was such that silica powder having an average particle size of 1.5 μm was added to PFA dispersion (the same as that used in Example 1) at a ratio of 3.5 parts by weight to 100 parts by weight of PFA powder. What was added and mixed as described above was used.

In the obtained tubular product, the thickness of the PFA tubular outer layer was 8 μm, the surface roughness Rz was 4.8 μm, and the surface resistance was 10 ¹⁰ Ω / □. When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1, the obtained image had a uniform silky surface. In the continuous paper feeding test, no trouble occurred even with 100,000 sheets.

Example 8 PFA dispersion in which carbon black was not mixed at the time of forming the fluororesin tubular outer layer on the outer peripheral surface of the fluororesin-containing polyimide resin tubular article (trade name, manufactured by DuPont, used in Example 1) The same operation as in Example 1 was carried out except that TE-334J) was used to obtain a tubular product having a multilayer structure.

In the obtained tubular product, the thickness of the PFA tubular outer layer was 8 μm, the surface roughness Rz was 1.7 μm, and the surface resistance was> 10 ¹² Ω / □. When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1, the obtained image had a glossy surface. In the continuous paper feeding test, no trouble occurred even after 100,000 sheets.

Example 9 By performing the same operation as in Example 1 except that the fluororesin tubular outer layer is not formed, a tubular article consisting only of the fluororesin powder-containing polyimide resin layer is obtained. The tubular product had a thickness of 30 μm, a surface roughness Rz of 1.2 μm, and a surface resistance of> 10 ¹² Ω / □.

When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1, the obtained image had a glossy surface. Also, the continuous paper passing test is 10
Even with 10,000 copies, there was no problem.

Comparative Example 1 A polyimide resin tubular product was obtained in the same manner as in Example 9 except that the PTFE powder was not added to the polyamic acid solution. The thickness of this tubular product was 30 μm, the surface roughness Rz was 1.0 μm, and the surface resistance was> 10 ¹² Ω / □.

When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1, a slip phenomenon occurred from 32,000 sheets in a continuous paper feeding test, and fixing was impossible after 45,000 sheets. became.

Comparative Example 2 A polyimide resin tubular inner layer (containing no fluororesin powder) and PF were prepared in the same manner as in Example 4 except that the PTFE powder was not added to the polyamic acid solution.
A tubular product having a multi-layer structure consisting of the tubular outer layer made of A was obtained.

In this tubular product, the thickness of the PFA tubular outer layer was 8 μm, the surface roughness Rz was 3.4 μm, and the surface resistance was 1.
It was × 10 ⁵ Ω / □. When this tubular product was used as a fixing belt of an image fixing device in the same manner as in Example 1,
In the continuous paper feeding test, slip phenomenon occurred from 26,000 sheets,
Fixing was impossible after 410,000 sheets.

[0065]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned constitution and the fluororesin powder is dispersed and contained in the polyimide resin tubular layer, a fixing belt having excellent sliding characteristics is provided as shown in the examples. it can.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of an image forming apparatus using a roller fixing method.

FIG. 2 is a schematic view of a main part of an image forming apparatus using a belt fixing method.

[Explanation of symbols]

 1 Heat Press 2 Press Roller 3 Transfer Paper 4 Heater 5 Thermal Ink 6 Image 7 Roller 8 Roller 9 Heater 10 Fixing Belt

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location C08L 79/08 LRB 9285-4J // (C08L 79/08 27:12) 79:08 (72) Inventor Masao Nakamura 1-2-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation (72) Inventor Tokio Fujita 1-21-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (4)

[Claims] 1. A composite tubular article comprising a tubular layer made of a polyimide resin, in which fluororesin powder is dispersed. 2. A composite tubular article characterized in that a fluororesin tubular outer layer is provided on the outer peripheral surface of a polyimide resin tubular inner layer in which fluororesin powder is dispersed. 3. The composite tubular article according to claim 2, wherein the powder is dispersed in the fluororesin tubular outer layer. 4. The composite tubular article according to claim 3, wherein the powder is a conductive powder.