JPH10301425A - Fixing roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the roller having superior releasing property, wear resistance, fixing property and durability by forming the joining layers and the toner releasing property layer with the material which is made by mixing fluorinated rubber and fluorinated resin with respective ranges of weight ratios. SOLUTION: An elastic body layer 2 is provided over a metallic roller base 1. The layer 2 is formed by the rubber composition which is made by mixing the rubber selected from the group of silicone rubber and fluorinated rubber and a packing material. Then, a joining layer 3, which is formed by the mixed material that is made by mixing fluorinated rubber and fluorinated resin with the weight ratio of 100:90 to 100:10, is provided over the layer 2. Then, a releasing property layer 4, which is made by mixing fluorinated rubber and fluorinated resin with the weight ratio of 90:100 to 10:100, is provided over the layer 3. Note that the layer 3 is constituted of the material used in the layer 4. Thus, the durability in joining is greatly improved by the mutual joining force of the fluorinated rubber and the fluorinated resin included in both layers 3 and 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic copying machine,
The present invention relates to a fixing roller used in a fixing unit of a laser beam printer, a facsimile, or the like, and more particularly, to a fixing roller having excellent release properties, abrasion resistance, and the like, and particularly having excellent fixing properties and durability.

[0002]

2. Description of the Related Art In general, an electrophotographic process is a process of forming an electrostatic latent image by exposing an image on a photoreceptor, and a process of attaching colored charged particles (toner) to the electrostatic latent image and developing the electrostatic latent image. Transferring the powder image (toner image) onto transfer paper (sheet-like transfer material or recording material), and fixing the unfixed powder image on the transfer paper by a method such as heating. .

There are various fixing methods such as heat roller fixing and pressure fixing. Among these, the fixing method most frequently used recently has a heating source such as an electric heater inside, and presses a pair of rollers whose outer surfaces are covered with rubber or resin with good releasability against the transfer paper, This is a heat roller fixing system in which toner is fused on transfer paper by passing between the rotating rollers. In this case, a heating source may be provided in only one of the pair of rollers to serve as a fixing roller for heating, and the other may be used as a pressure roller. The heat roller fixing method has the highest thermal efficiency and is suitable for high speed as compared with other fixing methods, but has a drawback that the life of the heat roller is short.

The fixing roller usually has a structure in which an elastic layer or a resin layer is provided on the outer surface of a metal roller (core metal) formed of a metal such as stainless steel or aluminum to prevent offset. ing. As a conventional fixing roller, for example, Japanese Patent Publication No. 1-24311 discloses an elastic layer made of fluoro rubber or silicone rubber on the outer surface of a metal roller, and a layer made of fluoro resin on this elastic layer. Has been proposed. This fixing roller has excellent non-adhesiveness on the surface, and when the claws for preventing paper wrap come into contact with the rotating roller, the elastic layer is deformed together with the thinly coated fluororesin layer. Since the fluororesin layer also deforms following the deformation of the elastic body, wear and damage of the fluororesin layer are prevented.

However, even with this conventional fixing roller, peeling tends to occur between the elastic layer and the fluororesin layer after long-term use, and the durability is not sufficient in this respect. Especially,
In a combination of an elastic layer made of silicone rubber and a toner release layer made of a fluororesin, it is difficult to bond the two and it is easy to cause interface peeling.

[0006] Japanese Patent Application Laid-Open No. 1-147576 discloses that
In a fixing roller in which a resin layer is formed on an elastic layer,
It has been proposed to form a large number of holes in the surface of an elastic layer that forms a boundary between an elastic layer and a resin layer, and to lock the resin layer by an anchor effect caused by the resin material entering the holes. In this way, on the outer surface of the metal roller, for example,
The quartz powder is removed with a polishing cloth to form a number of holes,
Next, a fluororesin layer is provided thereon. However, the silicone rubber forming the elastic layer and the fluororesin forming the resin layer are inherently good in releasability, and therefore have low adhesive strength therebetween. In addition, peeling occurs at the joint during use, and the durability is still insufficient.

Japanese Patent Application Laid-Open No. 7-49631 discloses a fixing roller having a structure in which an elastic layer and a release layer made of a fluororesin are provided. It has been proposed to provide a layer. In this method, the adhesive layer and the release layer are formed of the same material, so that they exhibit good adhesiveness for the time being, but still have insufficient durability in long-term use.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing roller which has good releasability, abrasion resistance, etc., and particularly has excellent fixing properties and durability.
A more specific object of the present invention is to stably secure good fixing properties, and to further form an elastic layer such as silicone rubber or fluoro rubber formed on a metal roller base material and an elastic layer formed thereon. It is an object of the present invention to provide a fixing roller which can solve the problem of delamination from the toner release layer and can be used for a long period of time.

[0009]

Means for Solving the Problems The inventors of the present invention have made intensive studies to overcome the problems of the prior art, and as a result, have found that at least one kind selected from the group consisting of silicone rubber and fluororubber is formed on a metal roller substrate. In a fixing roller in which an elastic layer formed of a rubber composition in which a filler is mixed with rubber, an adhesive layer made of a mixture of fluororubber and a fluororesin and a toner release layer are sequentially laminated, the adhesive layer is A mixture of fluoro rubber and fluoro resin in a weight ratio of 100: 90 to 100: 10 is formed, and the toner release layer is formed of fluoro rubber and fluoro resin in a ratio of 10: 100 to 90:10.
By forming the mixture with a weight ratio of 0, a fixing roller can be stably secured without impairing the elasticity of the roller, a delamination is suppressed, and a fixing roller having significantly improved durability can be obtained. Was found.

Since the fixing roller of the present invention has a fluororesin surface layer on its surface, it is excellent in releasability, abrasion resistance and the like.

Thus, according to the present invention, there is provided a fixing roller used in an apparatus for passing a copy paper on which a toner image is formed between a pair of rollers and heat-fixing the toner image on the copy paper, An elastic layer formed of a rubber composition in which a filler is blended with at least one kind of rubber selected from the group consisting of silicone rubber and fluorine rubber on the outer surface of a metal roller.
An adhesive layer formed of a mixture mixed at a weight ratio of 0:10;
A fixing roller provided with a release layer formed of a mixture mixed at a weight ratio of 0: 100 in this order is provided.

Hereinafter, the present invention will be described in detail. The fixing roller of the present invention will be described with reference to FIG. FIG.
1 is a schematic sectional view of a fixing roller of the present invention. The fixing roller of the present invention provides an elastic layer (2) formed of a rubber composition in which a filler is mixed with at least one rubber selected from the group consisting of silicone rubber and fluororubber on a metal roller substrate (1). On which an adhesive layer (3) formed of a mixture of a fluororubber and a fluororesin in a weight ratio of 100: 90 to 100: 10, and further a fluororubber and a fluororesin from 90: 100 A release layer (4) formed of a mixture mixed at a weight ratio of 10: 100 is provided. In the fixing roller of the present invention, since the adhesive layer is made of the material constituting the release layer, the adhesive durability is remarkably improved due to the mutual adhesive force of the fluorine rubber and the fluorine resin contained in both of them. Naturally, both layers are set to have different composition ratios so as to be suitable for each purpose. When used as a fixing roller, a heating source such as an electric heater is provided in the hollow of the roller base material.

As the material of the roller base material (metal core), a metal having good heat conductivity, such as aluminum or stainless steel, is used. The elastic layer formed on the outer surface of the metal roller needs to be able to withstand high-temperature conditions when used as a fixing roller. Therefore, heat-resistant silicone rubber, fluorine rubber, or a mixture thereof is used as the elastic material. Is used. Fillers and other additives are appropriately blended with these elastic materials to adjust thermal conductivity, adjust mechanical properties such as tensile strength and tear strength, and adjust rebound resilience. And an elastic layer is formed by using this.

As the silicone rubber and the fluoro rubber, general-purpose ones can be used. Examples of the silicone rubber include methyl silicone rubber, vinyl methyl silicone rubber, phenyl methyl silicone rubber, and fluoro silicone rubber. The fluororubber exhibits elasticity by a crosslinking reaction, and is a so-called vinylidenefluoride-based fluororubber containing vinylidene fluoride (VDF) as a main component and an alternating copolymer of tetrafluoroethylene (TFE) and propylene (P). And a propylene / tetrafluoroethylene-based fluororubber based on styrene. The materials in each of the exemplified groups can be used alone or in combination of two or more.

As the filler used for the elastic material, for example, carbon black, talc, mica, kaolin,
Titanium oxide, iron oxide, chromium oxide, calcium carbonate, calcium silicate, calcium sulfate, barium sulfate, magnesium carbonate, magnesium phosphate, graphite, silicon nitride,
Examples thereof include boron nitride (boron nitride), titanium nitride, molybdenum disulfide, hydrotalside, and metal powder. Among these, boron nitride is particularly effective in improving the interlayer adhesion between the elastic layer and the adhesive layer. Great effect.
These fillers can be used alone or in combination of two or more.

The mixing ratio of the filler is usually 5 to 100 parts by weight, preferably 10 to 8 parts by weight, per 100 parts by weight of rubber.
0 parts by weight, more preferably 20 to 70 parts by weight. If the compounding ratio is too large, the rebound resilience decreases, which is not preferable.

The thickness of the elastic layer can be appropriately determined depending on the desired rebound resilience, thermal conductivity and the like.
１1 mm, preferably about 0.15 to 0.5 mm. In the present invention, an adhesive layer made of a specific material is provided between the elastic layer and the release layer. As a material for forming the adhesive layer, a mixture obtained by blending a fluorine resin with a fluorine rubber is used. As the fluororesin in the adhesive layer, the same fluororesin as used in the release layer described later can be used.

As the adhesive layer, 10 to 90 parts by weight of fluororesin, preferably 20 to 100 parts by weight of fluororubber is used.
What is blended in the range of ８０80 parts by weight is used. If this specific compounding ratio is reduced, the effect of improving the adhesiveness is small,
Conversely, if it is excessively large, the adhesive layer becomes hard, and the elasticity of the elastic layer, which is capable of heating the toner by deforming and encapsulating it along the irregularities of the toner, is impaired, thereby causing poor fixing. The thickness of the adhesive layer is 0.1 to 50 μm.
m, preferably 1 to 30 μm, more preferably 5 to 20 μm
μm.

The fluororesin used for the toner release layer is a thermoplastic fluororesin having a relatively high melting point.
In order to enable continuous use of the fixing roller, those having particularly excellent heat resistance are preferable, and polytetrafluoroethylene (PT
FE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FE
P), tetrafluoroethylene / ethylene copolymer (E
TFE) is preferred.

In addition, a filler or other resin may be appropriately blended with the fluororesin as long as the releasability and heat resistance are not impaired. For example, a fluororesin to which a small amount of polyamideimide is added can be used as long as the degree of releasability required as a fixing roller is not impaired. Deviating from the specified mixing ratio of the fluoro rubber and the fluoro resin in the release layer causes a decrease in the mechanical properties of the film itself,
This causes a problem in durability. The thickness of the release layer is usually 0.1
５０50 μm, preferably 5-30 μm. If the thickness is too small, the release layer on the surface is worn out over a long period of use, and the adhesive layer or the elastic layer is exposed.

As a method for producing the fixing roller of the present invention, the outer surface of a metal roller is generally roughened by sand blasting or the like, subjected to a primer treatment, and then coated with a rubber composition containing a filler. Then, after vulcanization (hardening), it is formed into a required shape (for example, grinding into an inverted crown shape) as desired. A dispersion containing a dispersion of a non-sintered fluororesin and a fluororubber or a mixture containing a mixture of these is coated, dried, and further, a dispersion obtained by increasing the mixing ratio of the non-sintered fluororesin in a similar manner. A method of coating and then heating and sintering (firing) is given.

The fixing roller of the present invention can obtain good fixing properties from the beginning of use. This is because the rubber component is contained in the adhesive layer between the elastic layer and the release layer, so that the toner can be heated so as to be deformed and wrapped along the irregularities of the toner without impairing the elasticity of the elastic layer.

Further, the fixing roller of the present invention can withstand 500,000 continuous fixing sheets under normal use conditions, and does not cause delamination. This is presumed to be because the fluororesin of the adhesive layer and the fluororesin of the release layer are of the same material and have good affinity.

[0024]

The present invention will be specifically described below with reference to examples and comparative examples. [Example 1] After roughening the surface of an aluminum core metal having an outer diameter of 60 mmφ by sandblasting, a primer treatment was performed, and a silicone rubber elastic body was formed thereon to have a thickness of 200 µm. An adhesive layer for silicone rubber and fluoro rubber (GLP-103SR, manufactured by Daikin Industries, Ltd.) was applied on the outer periphery of the roller as an adhesive layer to several μm and dried at 70 ° C. for 10 minutes. On top of this, 10% by weight of a PTFE dispersion (manufactured by Daikin Industries, Ltd., EK-213) was used with respect to 90% by weight of fluoro rubber (manufactured by Daikin Industries, GLS-213).
4300 CRN) was applied to a thickness of 10 μm, dried, and further, as a release layer, 10% by weight of fluoro rubber (manufactured by Daikin Industries, GLS-213) and PTFE dispersion (manufactured by Daikin Industries, EK-213). 4300C
(RN) A mixture containing 90% by weight was applied to a thickness of 15 μm, and then baked at 450 ° C. for 10 minutes. After firing,
The surface was polished with a polishing film to obtain a fixing roller. [Example 2] Fluorine rubber (GLS-2 manufactured by Daikin Industries, Ltd.)
13) PTFE dispersion of 25% by weight to 75% by weight (EK-4300CRN, manufactured by Daikin Industries, Ltd.)
Is coated to a thickness of 10 μm, and after drying, a fluororubber (GL, manufactured by Daikin Industries, Ltd., GL
S-213) A fixing roller was obtained in the same manner as in [Example 1] except that a mixture containing 25% by weight and 75% by weight of a PTFE dispersion (manufactured by Daikin Industries, Ltd., EK-4300CRN) was applied to a thickness of 15 µm. Was. [Example 3] Fluorine rubber (GLS-2 manufactured by Daikin Industries, Ltd.)
13) PTFE dispersion of 40% by weight to 60% by weight (EK-4300CRN manufactured by Daikin Industries, Ltd.)
Is coated to a thickness of 10 μm, and after drying, a fluororubber (GL, manufactured by Daikin Industries, Ltd., GL
S-213) A fixing roller was obtained in the same manner as in [Example 1] except that a mixture containing 40% by weight and 60% by weight of a PTFE dispersion (manufactured by Daikin Industries, Ltd., EK-4300CRN) was applied to a thickness of 15 µm. Was. [Comparative Example 1] The surface of an aluminum core having an outer diameter of 60 mmφ was roughened by sandblasting, followed by a primer treatment, and a silicone rubber elastic body was formed thereon to have a thickness of 200 µm. An adhesive layer for silicone rubber and fluoro rubber (GLP-103SR, manufactured by Daikin Industries, Ltd.) was applied on the outer periphery of the roller as an adhesive layer to several μm and dried at 70 ° C. for 10 minutes. A fluororubber (GLS-213, manufactured by Daikin Industries, Ltd.) is coated thereon to a thickness of 10 μm, dried, and further, as a release layer, 30% by weight of fluororubber (GLS-213, manufactured by Daikin Industries, Ltd.) and PTFE are used. Dispersion (EK-4300CRN, manufactured by Daikin Industries, Ltd.)
The mixture containing 70% by weight was painted to a thickness of 15 μm and then baked at 450 ° C. for 10 minutes. After firing, the surface was polished with a polishing film to obtain a fixing roller. [Comparative Example 2] The surface of an aluminum core having an outer diameter of 60 mmφ was roughened by sandblasting, followed by a primer treatment, and a silicone rubber elastic body was formed thereon to a thickness of 200 µm. An adhesive layer for silicone rubber and fluoro rubber (GLP-103SR, manufactured by Daikin Industries, Ltd.) was applied on the outer periphery of the roller as an adhesive layer to several μm and dried at 70 ° C. for 10 minutes. On top of this, a PTFE dispersion (manufactured by Daikin Industries, EK-300) containing 30% by weight of fluorine rubber (manufactured by Daikin Industries, GLS-213) was 70% by weight.
4300 CRN) is applied to a thickness of 10 μm, and after drying, a PTFE dispersion (EK-4300 CRN, manufactured by Daikin Industries, Ltd.) is applied as a release layer to a thickness of 15 μm, and then at 450 ° C. Baking for 10 minutes. After firing, the surface was polished with a polishing film to obtain a fixing roller.

With respect to each of the fixing rollers obtained in the above Examples and Comparative Examples, the peel strength between the elastic layer and the release layer made of fluororesin was measured. Further, these fixing rollers were arranged in a fixing section of a copying machine, and a durability test was performed by continuous paper passing at a roller surface temperature of 180 ° C. Table 1 shows the results.

[0026]

[Table 1] (Measurement Method of Peeling Strength) A cut of 1 cm width was made on the surface of the fixing roller so as to reach the elastic layer, a part of the release layer and the adhesive layer were peeled off, and a tension gauge was attached to the part, and 90% in the circumferential direction. The strength at the time of peeling is measured in degrees.

[0027]

According to the present invention, there is provided a fixing roller having excellent releasability, abrasion resistance, particularly excellent fixing properties and durability.
The fixing roller of the present invention has improved adhesion between the elastic layer formed on the metal roller base and the release layer made of fluororesin. As a result, delamination during paper passing is suppressed,
It is resistant to mechanical shock and can be used stably for a long time. Further, since the fixing roller of the present invention is provided with a release layer made of a fluororesin, no offset occurs, and the fixing roller has an elastic layer as a lower layer, and the adhesive layer also has elasticity, so that the fixing property and the resistance are improved. Excellent wear properties. The fixing roller of the present invention is an electrophotographic copying machine, a laser beam printer,
It is effective when used as a heat-fixing roller in a fixing section of a facsimile or the like, and can be widely used not only as a heat-fixing roller but also as an elastic roller requiring heat resistance and release properties.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a fixing roller of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal core metal 2 Elastic layer 3 Adhesive layer 4 Release layer

Claims (1)

[Claims] 1. A fixing roller for use in an apparatus that heats and fixes a toner image formed on a copy paper by passing between a pair of rollers, wherein a group of silicone rubber and fluorine rubber is provided on an outer surface of a metal roller. In a fixing roller in which an elastic layer formed of a rubber composition in which a filler is blended with at least one kind of rubber selected from the group consisting of an adhesive layer made of a mixture of a fluororubber and a fluororesin, and a toner release layer are sequentially laminated, The adhesive layer is made of fluoro rubber and fluoro resin in 10
0:90 to 100: 10 by weight, and the toner release layer contains 9 parts of fluororubber and fluororesin.
A fixing roller, which is a mixture mixed at a weight ratio of 0: 100 to 10: 100.