JPH1048985A - Fixing roller and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing roller and its manufacturing method which can improve the adhering force of a core metal and an adhesive layer extensively. SOLUTION: In the fixing roller of a fixing device to fix a unfixed toner to a transfer paper, the projections of the uneven form formed on the surface of the core metal 2 of the fixing roller 1 are made in the form to hit a wedge to an outer layer (an adhesive layer 3 and a mold releasing layer 4) surrounding the core metal 2, when the fixing roller 1 conveys and rotates a paper. Consequently, the reduction of the adhesive force between the core metal 2 and the outer layer (the adhesive layer 3 and the mold releasing layer 4) surrounding the core metal 2 owing to the force generated in the reverse rotating direction to the rotating direction in order to convey the paper by the fixing roller 1 can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing roller used in an electrophotographic apparatus such as a copying machine and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic apparatus such as a copying machine, a heat roller method is known as one method used in a fixing device for fixing a toner image transferred onto a transfer sheet to a sheet. In the fixing process of the heat roller type fixing device, the transfer paper and the unfixed toner on the transfer paper are sandwiched in a contact portion between the heat roller and the backup roller by rotating a heat roller or a backup roller (pressure roller). The unfixed toner on the transfer paper is melted by the heat generated by the heat roller and the pressure applied between the heat roller and the backup roller, and the unfixed toner is fused and pressed on the transfer paper to form a copy image.

[0003] The basic configuration of a fixing roller used in such a heat roller system is a drum-shaped core made of aluminum or iron, and an adhesive layer mainly composed of a release layer formed on the core. And a release layer of a fluororesin having heat resistance and release properties formed on the adhesive layer.

In the above-described basic configuration of the fixing roller, the adhesive layer includes a fixing roller core metal and a release layer until the heat and pressure required for fixing the unfixed toner to the transfer paper are assured by the fixing roller. It is provided to prevent peeling off. This adhesive layer may be omitted depending on the necessity of adhesion.

A method of manufacturing such a fixing roller is to sandblast an aluminum or iron drum-shaped core metal at a projection angle of 0 °, and reduce the surface roughness of the core metal surface to a ten-point average roughness (JIS). B0601) Rz is reduced to about 15 μm or less. This is achieved by increasing the contact area between the core bar and the layer on the core bar, and roughening the surface of the core bar in a random shape to provide an anchor effect to the layer on the core bar, thereby increasing the contact between the core bar and the core bar. This is for improving the adhesion to the layer on the gold.

Next, an adhesive is applied to the surface of the core metal, a fluororesin serving as a release layer is applied thereon, and then calcination is performed to form a release layer. When used as a fixing roller, the surface of the release layer has a rough surface and easily adheres toner. For this reason, the surface of the release layer is ground or polished to smooth the surface roughness to about 3 μm or less in ten-point average roughness Rz.

[0007] Recently, as part of extending the life of the fixing roller, it has been desired that the adhesion between the core metal and the release layer be made highly durable. In addition, since the storage state and management method of the adhesive greatly affect the adhesiveness, the necessity of a wastewater treatment facility, and the heat conduction to the toner by the adhesive layer is reduced, the adhesive layer is used. It is desired to form the release layer directly on the cored bar by omitting the above.

[0008]

However, as described in the above-mentioned prior art, in the fixing roller of the heat roller type, since the core metal and the layer on the core metal are heated, the core metal and the layer on the core metal are heated. Due to the difference in the thermal expansion characteristics due to the difference in the material between the core metal and the core metal, there is a problem that a shift occurs between the core metal and the layer on the core metal, and the layer on the core metal is separated from the core metal.

Further, the layer on the core is pulled in a direction opposite to the rotation direction of the core by the rotational force of the fixing roller or the backup roller and the pressure between the fixing roller and the backup roller. There has been a problem that a gap occurs between the layer on the cored bar and the layer on the cored bar is separated from the cored bar.

In the fixing roller, the core of the fixing roller is formed in a drum shape in order to prevent the transfer paper from wrinkling when the transfer paper is conveyed. Due to this shape, when the fixing roller rotates, the diameter of the end of the fixing roller is longer than that of the center of the fixing roller, so that the linear velocity is high.

Therefore, when the transfer paper is transported, the transfer paper is pulled left and right with respect to the transport direction, so that it is possible to prevent the transfer paper from wrinkling. For this reason, the layer on the metal core is also pulled from the center of the fixing roller to both ends by the metal core, paper, and backup roller.

For this reason, the layer on the metal core is also pulled from the center of the fixing roller to both ends by the metal core, paper and the backup roller. This phenomenon is also considered to be a cause of the decrease in adhesion between the core metal and the layer on the core metal.

The coating peeled off by the pulling force is cut by the above-described force in the reverse rotation direction of the fixing roller and the force in the direction from the center to the end. By this cutting, the core metal having poor releasability is exposed to the outside.

The toner on the transfer paper adheres to the exposed surface of the metal core, and the adhered toner is again fixed at a different position on the same transfer paper or on a different transfer paper. Due to the occurrence of the offset phenomenon, there is a problem that an image fixed on the transfer paper becomes an abnormal image. Further, it is desired to not only solve the above problems but also omit the adhesive layer as described above.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing roller capable of greatly improving the adhesion between a core metal and an adhesive layer, and a method of manufacturing the same.

Another object of the present invention is to provide a fixing roller capable of omitting an adhesive layer by greatly improving the adhesion between a core metal and a release layer, and a method of manufacturing the same. is there.

[0017]

According to a first aspect of the present invention, there is provided a fixing roller of a fixing device for fixing an unfixed toner on a transfer sheet. The convex part of the formed concavo-convex shape is
It is characterized in that the fixing roller has a shape in which a wedge is hit on the outer layer surrounding the core bar when the fixing roller rotates in the paper conveyance.

Since the convex-concave portion formed on the surface of the core of the fixing roller has a shape in which a wedge is formed on the outer layer surrounding the core, the direction in which the fixing roller rotates for conveying the paper is reversed. It is possible to suppress a decrease in the adhesion between the core metal and the outer layer surrounding the core metal due to the force generated in the rotation direction.

According to a second aspect of the present invention, in the fixing roller according to the first aspect, the outer layer is an adhesive layer. A decrease in the adhesion between the core metal and the adhesive layer can be suppressed.

According to a third aspect of the present invention, in the fixing roller according to the first aspect, the outer layer is a release layer. A decrease in adhesion between the core metal and the release layer can be suppressed, and the adhesive layer can be omitted.

According to a fourth aspect of the present invention, in the method for manufacturing a fixing roller of a fixing device for fixing unfixed toner on transfer paper, the step of sandblasting the surface of the metal core of the fixing roller is performed. In addition, the sand blasting is characterized in that the projection is performed with a predetermined angle inclined in a direction in which the projection direction of the sand blast approaches the rotation direction of the fixing roller.

By forming the unevenness of the surface of the fixing roller core by sandblasting, the core and the release layer or the core and the adhesive layer are generated by the force generated in the direction opposite to the direction in which the fixing roller rotates for conveying the paper. And a decrease in the adhesive strength with the substrate can be suppressed.

In the method of manufacturing a fixing roller according to claim 5, the projection angle θ of the sandblast is 0 (degree).
<Θ <80 (degrees). The decrease in adhesion between the core metal and the release layer or the adhesive layer can be suppressed only by sandblasting.

According to a sixth aspect of the present invention, in the method of manufacturing a fixing roller of a fixing device for fixing an unfixed toner on a transfer sheet, the surface of the core of the fixing roller is formed by knurling. Forming,
After this knurling, a step of sandblasting to form smaller irregularities than the knurling is provided.When the fixing roller rotates in the paper conveyance direction, the convexities of the irregularities formed on the core metal surface of the fixing roller are provided. It is characterized in that a wedge is formed on the outer layer surrounding the cored bar.

By forming the surface of the fixing roller core by knurling and then sun blasting,
The adhesion between the core metal and the release layer or the adhesive layer can be improved.

According to a seventh aspect of the present invention, in the method of manufacturing a fixing roller according to the sixth aspect, the knurling is performed using a saw-toothed knurl. By forming the irregularities on the surface of the fixing roller core by knurling and sandblasting using a saw-toothed knurl, the core metal is generated by the force generated in the direction opposite to the direction in which the fixing roller rotates for paper conveyance. It is possible to suppress a decrease in adhesion between the release layer or the core metal and the adhesive layer.

According to an eighth aspect of the present invention, in the method for manufacturing a fixing roller according to the sixth aspect, the knurling is performed using a knurl having a sawtooth-like and twill-like composite shape.

The unevenness on the surface of the core metal of the fixing roller is formed by knurling using a saw-toothed and knurled knurl, and then the unevenness is formed by sandblasting to form the unevenness smaller than that of the knurling. It is possible to prevent a decrease in adhesion between the outer layer and the outer layer.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a basic configuration of a fixing roller according to an embodiment of the present invention. As shown in FIG.
The basic structure of the fixing roller 1 of the present invention is a drum-shaped core 2 made of aluminum or iron, an adhesive layer 3 formed on the core 2, and a mold release formed on the adhesive layer 3. In order to obtain adhesion between the core 2 and the adhesive layer 3, the outer surface of the core is provided with irregularities and roughened as described later.

FIG. 3 is a cross-sectional view conceptually showing the unevenness (wedge shape) of the surface of the metal core in a cross section orthogonal to the axis. A wedge is formed on the layer 3 in the reverse rotation direction of the paper transport rotation direction (hereinafter, rotation direction 5) of the fixing roller in the fixing device.

In the present embodiment, the adhesive layer 3 mainly composed of the material of the release layer 4 on the surface of the core metal 2 and the release of the heat-resistant and release-resistant fluororesin formed on the adhesive layer 3 are performed. And a layer 4.

Hereinafter, a method of manufacturing the fixing roller of the present invention will be described. Knurling and sandblasting, or only sandblasting on the surface of the cored bar 2,
The surface of the cored bar 2 is roughened. FIG. 2 is an explanatory view of a sandblasting apparatus for processing a core of a fixing roller according to the present invention.

The sand blasting machine is provided with a sand blast gun 8 capable of inclining the projection angle of the sand blast powder at a predetermined angle 7 from a straight line 6 passing through the center of the cored bar. Sandblast powder 9 is projected from the sandblast gun 8 toward the surface of the metal core.

The processing conditions are such that the projection angle 6 of the sandblast powder on the surface of the cored bar 2 is adjusted to form an uneven shape. Alternatively, sand blasting is applied to the unevenness after knurling using knurls of flat, twill, sawtooth or a combination of these, and fine unevenness is formed on the unevenness formed by knurling I do.

The other processing conditions depend on the material of the core 2 and the necessity of adhesion, and the material, shape and
The required conditions are changed by changing the pressing force against the core 2, the number of rotations of the knurl, the material of the sandblast powder, the particle size, the projection pressure, the projection angle, the discharge amount, the processing time, and the distance between the core 2 and the gun 8. Adjust appropriately to obtain roughness and shape.

Next, an adhesive mainly composed of the material of the release layer 4 is applied onto the cored bar 2 to form an adhesive layer 3. Next, a fluororesin serving as the release layer 4 is applied on the adhesive layer 3 and baked. Next, grinding or polishing is performed to smooth the surface of the release layer 4.

According to the present invention, as described below,
Since the adhesion between the core metal 2 and the release layer 4 could be improved, the adhesive layer 3 can be omitted according to the necessity of the adhesion between the core metal 2 and the release layer 4.

An embodiment will be described below with reference to the accompanying drawings. (Embodiment 1) FIG. 4 shows a cross section orthogonal to an axis near the surface of a metal core according to Embodiment 1, (a) is a cross section after knurling, (b) is a cross section after sandblasting, and FIG.
FIG. 3 is a diagram showing the eyes of a flat knurl used in Example 1.

As shown in FIG. 4A, knurling was performed on a 50 mm-diameter aluminum cored bar 12a using a flat knurl as shown in FIG. The direction of the convex portion of the unevenness formed by the knurling is radially formed with respect to the roller surface. The apex angle of the tip of the projection was 90 degrees.

As shown in FIG. 4B, while the core 12a is rotated at 10 rpm in the rotation direction of the fixing roller with respect to the surface of the knurled core 12a, the projection angle of the sandblast powder is 0 °. Was subjected to sand blasting, and fine irregularities were formed on the irregular surface formed by knurling to roughen the surface. In this roughening, the core metal 1
2b Surface roughness is 10-point average roughness R in the circumferential direction of the surface
It became 15 μm in z.

The other processing conditions for sandblasting were as follows: sandblast powder # 2000 was used, and the projection pressure was 6000K.
Pa, the discharge rate is 40 g / s, the processing time is 120 sec, the distance between the core 2 and the gun 8 is 150 mm, and the range in which the sandblast powder of the core 2 is projected from the center line of the gun 8 to the left and right with respect to the circumferential direction. It was 10 mm each along the outer periphery of the gold 2.

Next, a PFA (perfluoroalkoxy resin) adhesive is applied on the cored bar 2 and the adhesive layer 3 is formed so that the thickness of the adhesive layer 3 becomes 5 μm after the release layer 4 is fired. And those not forming an adhesive layer without applying an adhesive.

Next, PFA is applied on the adhesive layer 3 or the core 2.
Electrostatic coating of powder coating mainly composed of
Then, the release layer 4 was formed. The surface of the release layer 4 was ground or polished, the thickness of the release layer 4 was set to 20 μm, and the surface roughness was reduced to about 3 μm or less as a ten-point average roughness Rz to smooth the surface of the release layer 4.

The fixing roller produced by the above method is mounted on a copying machine (FT5500 manufactured by Ricoh), and paper is passed (copied) under actual use conditions, and the adhesion between the core metal 2 and the release layer 4 is evaluated. Was.

Example 2 FIG. 6 is a cross-sectional view showing the vicinity of the surface of a metal core according to Example 2 and orthogonal to the axis after sandblasting at a projection angle of -50 degrees. Aluminum diameter 50
The surface of the cored bar 22 is subjected to sandblasting by inclining the projection angle 7 of the sandblasted powder at −50 degrees in the rotation direction 5 of the fixing roller 1 from the vertical to the surface of the cored bar 22, thereby roughening the surface of the cored bar 22. The surface roughness was set to 15 μm as a ten-point average roughness Rz in the circumferential direction of No. 22.

Other processing conditions for sandblasting are as follows: while the core metal 22 is rotated at 0.5 rpm in the rotation direction of the fixing roller, the sandblast powder # 120 is used, and the projection pressure is 3
00 to 600 KPa, discharge rate 40 g / s, processing time 12
0 sec, the distance between the core bar 22 and the gun 8 is 150 mm, and the range of the sand blast powder of the core bar 2 projected on the circumferential direction is 10 mm each along the outer circumference of the core bar 22 to the left and right from the center line of the gun 8. did.

The following processing steps were performed in the same manner as in Example 1. The fixing roller manufactured by the above method is mounted on a copying machine (FT5500 manufactured by Ricoh), and the paper is passed (copied) under actual use conditions.
Then, the adhesion between the core metal 2 and the release layer 4 was evaluated.

(Embodiment 3) FIG. 7 is a cross-sectional view orthogonal to the axis after sandblasting at a projection angle of -20 degrees, showing the vicinity of the core metal surface according to Embodiment 3.

The surface of the aluminum core bar 32 having a diameter of 50 mm is subjected to sand blasting by inclining the projection angle 7 of the sandblast powder at −20 degrees in the rotation direction 5 of the fixing roller 1 from the vertical. And the surface roughness is 15 μm in terms of the ten-point average roughness Rz with respect to the circumferential direction of the cored bar 32.
m. The other processing conditions for sandblasting are the same as in Example 2. The following processing steps were performed in the same manner as in Example 1.

In the same manner as in Example 2, the fixing roller manufactured by the above method was mounted on a copying machine (FT5500 manufactured by Ricoh), and paper was passed (copied) under actual use conditions. Was evaluated for adhesion.

(Conventional Example) FIG. 8 is a cross-sectional view orthogonal to the axis after sandblasting at a projection angle of 0 °, showing the vicinity of the core metal surface according to the conventional example.

The surface of the aluminum core bar 502 having a diameter of 50 mm is subjected to sand blasting by inclining the projection angle 7 of the sand blast powder from the vertical in the rotation direction 5 of the fixing roller 1 to 0 °. Roughened, core metal 502
Surface roughness is 15 points in the circumferential direction of
μm. The other processing conditions for sandblasting are the same as in Example 2. The following processing steps were performed in the same manner as in Example 1.

In the same manner as in Example 2, the fixing roller manufactured by the above method was mounted on a copying machine (FT5500 manufactured by Ricoh), and paper passing (copying) was performed under actual use conditions. Was evaluated for adhesion.

(Comparative Example 1) FIG. 5 is a cross-sectional view showing the vicinity of the surface of a metal core according to Comparative Example 1 and orthogonal to the axis after sandblasting at a projection angle of -80 degrees.

The surface of the aluminum core bar 102 having a diameter of 50 mm is subjected to sand blasting by inclining the projection angle 7 of the sandblast powder at -80 degrees in the rotation direction 5 of the fixing roller 1 from a vertical direction. Is roughened and the core metal 1
02, the surface roughness was set to 15 μm in ten-point average roughness Rz with respect to the circumferential direction. The other processing conditions for sandblasting are the same as in Example 2. The following processing steps were performed in the same manner as in Example 1.

In the same manner as in Example 2, the fixing roller manufactured by the above method was mounted on a copying machine (FT5500 manufactured by Ricoh), and paper passing (copying) was performed under actual use conditions. Was evaluated for adhesion.

(Comparative Example 2) FIG. 9 is a cross-sectional view orthogonal to the axis after sandblasting at a projection angle of 20 degrees, showing the vicinity of the core metal surface according to Comparative Example 2.

The surface of the cored bar 202 made of aluminum and having a diameter of 50 mm is subjected to sandblasting by inclining the projection angle 7 of the sandblasted powder at 20 degrees in the rotation direction 5 of the fixing roller 1 from the vertical direction. Roughened, metal core 20
In the circumferential direction of No. 2, the surface roughness is 1 point at 10 point average roughness Rz.
The thickness was 5 μm. The other processing conditions for sandblasting are the same as in Example 2. The following processing steps were performed in the same manner as in Example 1.

In the same manner as in Example 2, the fixing roller manufactured by the above method was mounted on a copying machine (FT5500 manufactured by Ricoh), and paper passing (copying) was performed under actual use conditions. Was evaluated for adhesion.

(Comparative Example 3) FIG. 10 is a cross-sectional view orthogonal to the axis after sandblasting at a projection angle of 50 degrees, showing the vicinity of the core metal surface according to Comparative Example 3.

The surface of the core bar 302 made of aluminum and having a diameter of 50 mm is subjected to sand blasting by inclining the projection angle 7 of the sandblast powder at 50 degrees from the vertical in the rotation direction 5 of the fixing roller 1 to 50 degrees. The surface is roughened, and the surface roughness is 15 μm in terms of the ten-point average roughness Rz with respect to the circumferential direction of the cored bar 2.
m. The other processing conditions for sandblasting are the same as in Example 2. The following processing steps were performed in the same manner as in Example 1.

(Comparative Example 3) In the same manner as in Example 2, a fixing roller manufactured by the above method was used for a copying machine (FT550 manufactured by Ricoh).
0), paper passing (copying) was performed under actual use conditions, and the adhesion between the core metal 302 and the release layer 4 was evaluated.

(Comparative Example 4) FIG. 11 is a cross-sectional view orthogonal to the axis after sandblasting at a projection angle of 80 degrees, showing the vicinity of the core metal surface according to Comparative Example 4. Aluminum diameter 50
mm from the surface of the core metal 402 from the fixing roller 1
The sandblasting process is performed by inclining the projection angle 7 of the sandblast powder in the rotation direction 5 of 80 degrees to 80 degrees to roughen the surface of the metal core 402, and the surface roughness of the metal core 402 with respect to the circumferential direction is 10-point average roughness. The height Rz was 15 μm. Other processing conditions for sandblasting are the same as in Example 2. The following processing steps were performed in the same manner as in Example 1.

In the same manner as in Example 2, the fixing roller manufactured by the above method was mounted on a copying machine (FT5500 manufactured by Ricoh), and paper passing (copying) was performed under actual use conditions. Was evaluated for adhesion.

(Embodiment 4) FIGS. 12A and 12B show the vicinity of the surface of a metal core according to Example 4, in which FIG. 12A is a cross-sectional view orthogonal to the axis after knurling, and FIG. FIG. 16 is a cross-sectional view showing the vicinity and orthogonal to the axis after sandblasting. FIG. 16 is a diagram showing the eyes of a saw-tooth knurl used in the fourth embodiment.

An aluminum core bar 42a having a diameter of 50 mm is
Knurling was performed using a saw-toothed knurl shown in FIG. The concavo-convex shape formed by this knurling process is such that the slope of the projection in the rotation direction 5 side is perpendicular to the surface of the cored bar 42a, and the apex angle of the tip of the projection is 45 degrees with respect to the circumferential direction. did. The same processes as those of Example 1 were performed on the knurled cored bar 42a after the sandblasting, and the same evaluation was performed.

(Embodiment 5) FIGS. 13A and 13B show the vicinity of the surface of a metal core according to Embodiment 5, in which FIG. 13A is a sectional view orthogonal to the axis after knurling, and FIG. 13B is orthogonal to the axis after sandblasting. FIG. 15 is a sectional view showing a saw-toothed and twill-shaped knurl used in the fifth embodiment, and FIG.
(B) is a cross-sectional view taken along line CC in (a), (c) is a cross-sectional view taken along line DD in (a), (d) is a perspective view showing a main part of the saw-toothed and knurled knurl, and (e). () Is a perspective view showing a main part of the surface of the cored bar provided by sawtooth and twill knurls.

A 50 mm-diameter cored bar 52 made of aluminum was subjected to knurling using knurls having a sawtooth and twill composite shape shown in FIG. The concavo-convex shape formed by the knurling process is such that the slope of the convex portion on the rotation direction 5 side is perpendicular to the surface of the cored bar 52 and has irregularities in the axial direction of the fixing roller. The angle of the peak of this projection is 45 degrees with respect to the circumferential direction, and 9 degrees with respect to the axial direction.
0 degrees. On the knurled core 2,
Processing after sandblasting was performed in the same manner as in Example 1, and the same evaluation was performed. Next, Table 1 shows the evaluation results of Examples 1 to 5 described above.

[0069]

[Table 1]

From Table 1, as a prerequisite for the evaluation, it was determined that a sample having a large number of peels had a long life with respect to the adhesion between the core metal and the release layer 4 and the adhesion between the core metal and the adhesive layer 3. I do.

In the case where the adhesive layer 3 is not added, the case where the projection angle is 0 degree in the conventional example and the case where the projection angle 6 in the second embodiment is −
When compared with the case where the projection angle is set to 50 degrees and the case where the projection angle of the third embodiment is set to −20 degrees, the convex portion of the concavo-convex formed on the cored bar by the sandblasting process is used in the direction 5 in which the fixing roller rotates for conveying the paper. The convex portion has a wedge shape on the side, and the adhesion is improved. This is because, since the convex portion has a wedge shape, the coating of the fixing roller is pushed into the unevenness by the force acting in the direction opposite to the direction 5 in which the fixing roller rotates for paper conveyance, and the anchor effect is provided. This is because the adhesion between the core metal and the release layer 4 is improved as compared with the case where the protrusions are formed perpendicular to the surface of the core metal.

When the projection angle 6 is ± 80 degrees as in Comparative Examples 1 and 4, the projection angles 6 are 0 degree, ± 20 degrees, ± 5 degrees.
Since the sandblast powder is projected along the surface of the metal core, the effect of grinding the surface of the metal core along the surface is greater than in the case of 0 degrees, so that it is difficult to form a wedge shape, resulting in poor adhesion. .

When the projection angle 6 is set to 20 degrees or 50 degrees as in Comparative Examples 2 and 3, a wedge-shaped convex portion is formed on the side opposite to the rotation direction 5 side. More
The anchor effect of pushing into the unevenness is not obtained, and the adhesion is reduced because the inclination of the wedge shape is inclined in the direction opposite to the rotation direction 5 by increasing the angle.

In Examples 1, 4, and 5,
The adhesion is improved in the order of 4 and 5. This is because the shape of the knurl has a sawtooth shape rather than a flat shape, and the rotation direction of the convex portion is 5.
Since the side slope is perpendicular to the entire surface of the metal core, the anchor effect of pushing the coating into the unevenness during rotation is greater, and the adhesion is improved. Further, comparing Example 4 and Example 5, it can be seen that the adhesiveness is improved when the saw-toothed and knurled knurls are used as compared to when the serrated knurls are used. The shape is also uneven in the axial direction of the fixing roller, so that the film during rotation can be made more uneven by the force of pulling the film from the center to the end due to the drum shape of the cored bar. It can be seen that the anchor effect of pushing in is obtained, and the adhesion is improved.

Further, comparing Example 1 with the conventional example,
It can be seen from the following reason that the combined processing of the knurling and the sandblasting has improved the adhesion rather than the sandblasting alone. That is, when the surface roughness of the core metal surface is made equal and the adhesion is evaluated, in order to form irregularities only on the core metal by sandblasting, the particle size of the sandblast powder must be larger than in the case of composite processing. Rather, comparing the shape of the unevenness, the unevenness formed on the surface of the core metal only by sand blasting is larger than the unevenness that was subjected to sand blasting after knurling,
The anchor effect with the coating is reduced and the adhesion is inferior.
Although the case where the adhesive layer 3 is not added has been described above, the same effect is obtained when the adhesive layer 3 is added.

Finally, there is an adhesive layer in the conventional production method,
Adhesion force between the case where the projection angle 6 is 0 degree and the case without the adhesive layer in Example 5 is equivalent, and the same adhesion as when the adhesive layer is added can be obtained without adding the adhesive layer. . 4 to 13, the length of each orthogonal arrow is 10
μm.

[0077]

As is apparent from the above description, according to the first aspect of the present invention, in the fixing roller of the fixing device for fixing the unfixed toner on the transfer paper, the uneven shape formed on the surface of the core metal of the fixing roller The convex portion of the fixing roller has a shape in which a wedge is hit on an outer layer surrounding the metal core when the fixing roller rotates in the sheet conveying direction. Therefore, the direction in which the fixing roller rotates for conveying the sheet when the fixing roller rotates. Of the core metal and the outer layer surrounding the core metal due to the force generated in the reverse rotation direction can be suppressed.

According to the second aspect of the present invention, it is possible to suppress a decrease in the adhesion between the core metal and the adhesive layer.

Further, according to the third aspect of the present invention, it is possible to suppress a decrease in the adhesion between the core metal and the release layer, and to omit the adhesive layer.

According to the fourth aspect of the present invention, the unevenness on the surface of the metal core of the fixing roller is formed by sandblasting, so that the fixing roller rotates for conveying the paper when the fixing roller in the fixing device rotates. In this case, it is possible to suppress a decrease in the adhesion between the core metal and the release layer or the adhesive layer due to the force generated in the reverse rotation direction.

According to the fifth aspect of the present invention, it is possible to suppress a decrease in the adhesion between the core metal and the release layer or the adhesive layer only by the sandblast treatment.

According to the sixth aspect of the present invention, the adhesion between the core metal and the release layer or the adhesive layer is improved by forming the unevenness on the surface of the fixing roller by knurling and then performing sun blast processing. Can be improved.

According to the seventh aspect of the present invention, in the fixing device according to the sixth aspect, the unevenness on the surface of the fixing roller core is formed by knurling using a saw-tooth knurl and sandblasting. When the fixing roller rotates, it is possible to suppress a decrease in the adhesion force between the core metal and the release layer or the adhesive layer due to the force generated in the reverse rotation direction of the rotation of the fixing roller for conveying the paper.

According to an eighth aspect of the present invention, in the sixth aspect, the unevenness on the surface of the metal core of the fixing roller is formed by knurling using a saw-toothed and knurled knurl, and then sandblasted. By forming smaller irregularities than the knurling by processing, it is possible to prevent a decrease in the adhesion between the core metal and its outer layer, so that even if the layer on the core metal is pulled in the direction opposite to the rotation direction of the core metal. In addition, there is almost no displacement between the cored bar and the layer on the cored bar, so that the layer on the cored bar can be prevented from peeling off from the cored bar.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a fixing roller.

FIG. 2 is an explanatory diagram of sand blasting of a fixing roller core according to the present invention.

FIG. 3 is a cross-sectional view of irregularities (wedge shape) on the surface of a cored bar in a cross section orthogonal to the axis.

FIG. 4 shows a cross section orthogonal to an axis near the surface of a cored bar according to the first embodiment, where (a) is a cross-sectional view after knurling, and (b).
FIG. 3 is a cross-sectional view after sandblasting.

FIG. 5 is a cross-sectional view orthogonal to the axis after sandblasting at a projection angle of −80 degrees, showing the vicinity of the core metal surface according to Comparative Example 1.

FIG. 6 is a cross-sectional view showing the vicinity of a core metal surface according to a second embodiment and orthogonal to an axis after sandblasting at a projection angle of −50 degrees.

FIG. 7 is a cross-sectional view orthogonal to an axis after sandblasting at a projection angle of −20 degrees, showing the vicinity of a core metal surface according to a third embodiment.

FIG. 8 shows the vicinity of a core metal surface according to a conventional example, and shows a projection angle of 0;
It is sectional drawing orthogonal to the axis | shaft after a degree of sandblasting.

FIG. 9 is a cross-sectional view showing the vicinity of a core metal surface according to Comparative Example 2 and orthogonal to the axis after sandblasting at a projection angle of 20 degrees.

FIG. 10 is a cross-sectional view orthogonal to the axis after sandblasting at a projection angle of 50 degrees, showing the vicinity of the core metal surface according to Comparative Example 3.

FIG. 11 is a cross-sectional view showing the vicinity of a core metal surface according to Comparative Example 4 and orthogonal to an axis after sandblasting at a projection angle of 80 degrees.

12A and 12B show the vicinity of the surface of a cored bar according to the fourth embodiment, and FIG.
Is a cross-sectional view orthogonal to the axis showing knurling, (b)
FIG. 3 is a cross-sectional view orthogonal to an axis showing a state after sandblasting.

13A and 13B show the vicinity of the core metal surface according to Example 5, and FIG.
FIG. 2 is a cross-sectional view orthogonal to the axis after knurling, and FIG. 2B is a cross-sectional view orthogonal to the axis after sandblasting.

14A and 14B are diagrams illustrating the eyes of a flat knurl used in Example 1, where FIG. 14A is a plan view and FIG. 14B is a view A in FIG.
It is -A sectional drawing.

FIGS. 15A and 15B are diagrams showing a saw-toothed and knurled knurl used in Example 5, wherein FIG. 15A is a plan view, FIG. 15B is a cross-sectional view taken along line CC in FIG. 15A, and FIG. ) DD sectional view in the figure,
(D) is a perspective view showing a main part of the saw-toothed and knurled knurl, and (e) is a perspective view showing a main part of the core metal surface provided by the saw-toothed and knurled knurl.

FIG. 16 is a diagram showing the eyes of a serrated knurl used in Example 4.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Fixing roller 2 Core metal 3 Adhesive layer 4 Release layer 5 Rotation direction of paper conveyance of a fixing roller in a fixing device 7 Projection angle of sandblast powder 8 Sandblast gun

Claims (8)

[Claims] In a fixing roller of a fixing device for fixing unfixed toner on a transfer sheet, a convex portion having a concave and convex shape formed on a surface of a metal core of the fixing roller is provided with a core when the fixing roller rotates for conveying the paper. A fixing roller having a shape in which a wedge is hit on an outer layer surrounding gold. 2. The fixing roller according to claim 1, wherein the outer layer is an adhesive layer. 3. The fixing roller according to claim 1, wherein the outer layer is a release layer. 4. A method of manufacturing a fixing roller of a fixing device for fixing an unfixed toner on a transfer sheet, comprising a step of sandblasting a surface of a metal core of the fixing roller, wherein the sandblasting is performed in a rotational direction of the fixing roller. A method for manufacturing a fixing roller, wherein the projection is performed by inclining the sandblast at a predetermined angle in a direction in which the projection direction approaches. 5. The projection angle θ of the sandblast is 0.
The method of claim 4, wherein (degree) <θ <80 (degree). 6. A method of manufacturing a fixing roller of a fixing device for fixing an unfixed toner on transfer paper, wherein a step of forming irregularities by knurling the surface of a core metal of the fixing roller, and the knurl after the knurling And a step of sand blasting to form irregularities smaller than the processing, wherein the convex-shaped projections formed on the surface of the core metal of the fixing roller are formed on the outer layer surrounding the core metal when the fixing roller is rotated for paper conveyance. A method of manufacturing a fixing roller, wherein the fixing roller is shaped to wedge. 7. The method according to claim 6, wherein the knurling process uses a knurl having a sawtooth shape. 8. The method of manufacturing a fixing roller according to claim 6, wherein the knurl processing uses a knurl having a sawtooth-like and twill-like composite shape.