JP2008256786A - Seamless belt and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide an endless belt which does not cause irregular transfer or irregular fixing due to meandering when rotating around a roller such as a transfer roller or a fixing roller, and which is more improved in fixing efficiency and transfer efficiency and excels in shape holding property and durability. <P>SOLUTION: The seamless belt 20 is reinforced with annular knitted cloth 7 formed of yarns 1 and 2 composed of many heat resistant fibers by garter stitch (purl stitch) and having a surface layer 5 and a back layer 6 constituted of a knit 3 and a purl 4. The seamless belt 20 is provided with a thin film 9 to which many heat resistant fibers constituting the yarns 1 and 2 are partially attached with an adhesive composed of hardened silicone resin and which is composed of the hardened silicone resin from the outside part of the back layer 6 of the annular knitted cloth 7 to a part appearing to the outer surface thereof. The thin film 9 is provided with many fine air holes 12 communicating with the outside surface, and is provided with a smooth surface 11 on its outside surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an endless belt used as a fixing transfer belt, a transfer belt, an intermediate transfer belt, a sublimation transfer belt or the like in an image forming apparatus such as a copying machine, a facsimile machine, or a printer.

Conventionally, as an endless belt, for example, a film belt composed of a thermoplastic resin and rubber or a thermoplastic elastomer is used as a seamless belt for an intermediate transfer belt of a copying machine / printer (see Patent Document 1). At least one of the annular woven fabrics obtained by bringing the resin into contact with the annular woven fabric in the form of a resin liquid, solution, dispersion, melt, etc. by means of impregnation, application, spraying, etc., drying, curing and solidifying. By providing a resin coating layer on the ring, a circular woven fabric used for applications such as fire hoses, escape sheets, bandages, rotary screens, conveyor belts, ink ribbons, tire tubes, etc. (see Patent Document 2). A knitted fabric, a woven fabric, a cut fiber, a pulp, paper, at least one component comprising a fiber composed of a melt anisotropic aromatic polyester polymer, To reinforce the film-like belt in what in any form of woven fabric, which the endless belt which is excellent in printing durability can be faster (see Patent Document 3.) Have been proposed.
Japanese Unexamined Patent Publication No. 2000-172088 JP-A-1-92445 JP-A-2005-292698

  In the seamless belt for an intermediate transfer belt of a copying machine / printer described in Patent Document 1, the seamless belt is composed of a thermoplastic resin as a hard material and rubber or a thermoplastic elastomer as a soft material. Therefore, this rubber or thermoplastic elastomer can stretch when the external force of the seamless belt is applied to compensate for a decrease in mechanical strength such as cracks, and can stabilize the dimensional accuracy of the seamless belt. However, it has not yet reached a point where it is possible to prevent a decrease in mechanical strength and a decrease in dimensional accuracy of the seamless belt caused by long-term use. Therefore, there was still a problem with the durability of the seamless belt.

  In the annular woven fabric described in Patent Document 2, the resin is brought into contact with the annular woven fabric in the form of a resin liquid, a solution, a dispersion, a melt, or the like by means of impregnation, application, spraying, and the like, and then dried and cured. Since the resin coating layer is provided on at least one of the annular woven fabrics, the durability of the annular woven fabric is improved by having the annular woven fabric. The surface of the annular woven fabric is covered with the problem that the unevenness of the transfer occurs due to meandering when rotating around the rollers such as the fixing roller, the transfer roller, and the fixing roller because the elasticity of the roller is insufficient. Since the resin coating layer is not smooth, the transferred toner image may be misaligned or an unnatural color pattern may be formed, and the resin coating layer coated on the surface of the annular woven fabric may be breathable. Thermal conductivity and heat preservation during heating The problem that the fixing efficiency and the transfer efficiency are lowered due to the inability to ensure sufficient, and the resin coating layer coated on the surface of the annular woven fabric is not breathable, so that the sublimation ink is not heated when heated. There was a problem that the ink escaped because there was no escape for vapor during sublimation.

  In the endless belt described in Patent Document 3, a knitted fabric, a woven fabric, a cut fiber, a pulp, a paper, or a nonwoven fabric, in which at least one component is composed of a fiber composed of a melt anisotropic aromatic polyester polymer. Since the film belt was reinforced with a belt, the durability of the endless belt was improved. However, like the one described in Patent Document 2, since the endless belt is not sufficiently stretchable, a fixing roller, a transfer roller, The problem is that unevenness of fixing and transfer occurs due to meandering when rotating around a roller such as a fixing roller, and the surface of the resin coating layer of the endless belt is not smooth, resulting in pattern deviation in the transferred toner image. And unnatural color patterns are formed, and the resin coating layer of the endless belt is not breathable. There is a problem that the temperature distribution may become impossible uniform fixing becomes uneven in order.

  The present invention aims to solve this problem.

  In other words, the present invention meanders when rotating around a roller such as a transfer roller or a fixing roller, causing transfer unevenness or fixing unevenness, or pattern deviation in the transferred toner image or unnatural color pattern. In addition, since there is no vent hole, there is no escape of vapor when the sublimation ink sublimates during heating, and the ink does not bleed, and the shape retention and the fixing efficiency and transfer efficiency are further improved. The purpose is to provide an endless belt with excellent durability at low cost.

In order to achieve the above-mentioned object, the invention described in claim 1 includes a surface layer and a back layer formed by garter knitting with yarns made of a large number of heat-resistant fibers. In having a seamless belt reinforced with an annular knitted fabric,
(A) A number of heat-resistant fibers constituting the yarn are partially bonded with an adhesive composed of a cured silicone resin,
(B) A thin film made of the cured silicone resin is provided from the outer part of the back layer of the annular knitted fabric to the part that protrudes to the outer surface,
(C) the thin film is provided with a number of fine vents leading to its outer surface; and
(D) A seamless belt characterized in that a smooth surface is provided on the outer surface of the thin film.

  The invention described in claim 2 is the invention described in claim 1, wherein the heat resistant fiber is an aromatic polyamide heat resistant fiber, a fluorine resin, a polyimide resin, a carbon fiber, and a polyarylate. It is characterized by being at least one heat-resistant fiber selected from fibers.

The invention described in claim 3 is the invention described in claim 1 or 2, wherein the air permeability of the seamless belt (JIS L1096 6.27.1) is ^{3 to} 8 cm ³ / cm ² / sec. It is characterized by this.

  The invention described in claim 4 is the invention described in any one of claims 1 to 3, wherein the seamless belt is a transfer belt having the smooth surface as a transfer surface. It is what.

  The invention described in claim 5 is the invention described in any one of claims 1 to 3, wherein the seamless belt is an intermediate transfer belt having the smooth surface as a transfer surface. It is a feature.

  The invention described in claim 6 is the invention described in any one of claims 1 to 3, wherein the seamless belt is a fixing belt.

The invention described in claim 7 is:
(A) An annular knitting having a surface layer and a back layer composed of a front surface and a back surface, which are formed by garter knitting with yarns made of a large number of heat-resistant fibers on the outer surface of a metal drum processed into a mirror surface Extrapolating the cloth,
(B) A coating liquid containing a silicone resin is applied to the outer surface of the surface layer of the annular knitted fabric extrapolated to the outer surface of the metal drum so as to have a coating amount of 1.9 to 3.2 Kg / m ^2. Applying with a doctor blade, the coating solution is impregnated into the yarn composed of a large number of heat-resistant fibers, and a coating thin film made of the coating solution is discharged from the outer part of the back layer of the annular knitted fabric onto the outer surface. Forming over the part,
(C) In a state where the annular knitted fabric coated with the coating liquid is extrapolated to the outer surface of the metal drum, the annular knitted fabric is subjected to a heat drying treatment at 60 to 70 ° C. Drying the solvent, and
(D) A number of heat-resistant fibers constituting the yarn were cured by subjecting the heat-dried annular knitted fabric to a heat-curing treatment at 130 to 140 ° C. to cure the silicone resin. Silicone partially bonded with an adhesive composed of a silicone-based resin and cured from the outer portion of the back layer of the annular knitted fabric on the side facing the outer surface of the metal drum to the portion protruding to the outer surface Characterized in that it has a step of forming a thin film composed of a resin, forming a number of fine vents leading to the outer surface of the thin film, and forming a smooth surface on the outer surface of the thin film. This is a seamless belt manufacturing method.

  The invention described in claim 8 is the invention described in claim 7, wherein the heat resistant fiber is an aromatic polyamide heat resistant fiber, a fluorine resin, a polyimide resin, a carbon fiber, and a polyarylate. It is characterized by being at least one heat-resistant fiber selected from fibers.

  The invention described in claim 9 is the invention described in claim 7 or 8, wherein the coating liquid containing the silicone resin is 4 to 6 parts by weight of a silicone resin and 0.5 to 1 weight of an inorganic filler. And 3 to 5 parts by weight of a solvent.

According to the invention described in claims 1, 4 to 6, it is formed by garter knitting with yarns composed of a large number of heat-resistant fibers, and has a surface layer and a back layer composed of a front surface and a back surface, In a seamless belt reinforced with an annular knitted fabric,
(A) A number of heat-resistant fibers constituting the yarn are partially bonded with an adhesive composed of a cured silicone resin,
(B) A thin film made of the cured silicone resin is provided from the outer part of the back layer of the annular knitted fabric to the part that protrudes to the outer surface,
(C) the thin film is provided with a number of fine vents leading to its outer surface; and
(D) Since a smooth surface is provided on the outer surface of the thin film, the film is meandered when rotating around a roller such as a transfer roller or a fixing roller, and transfer unevenness or fixing unevenness is generated or transferred. There is no pattern displacement in the toner image, an unnatural color pattern is formed, there is no air permeability, so there is no vapor escape when sublimation ink sublimates during heating, and ink does not bleed, An endless belt excellent in shape retention and durability with further improved fixing efficiency and transfer efficiency can be provided at low cost.

  According to the invention described in claims 2 and 8, the heat resistant fiber is at least one selected from aromatic polyamide heat resistant fiber, fluorine resin, polyimide resin, carbon fiber and polyarylate fiber. Since it is a seed heat-resistant fiber, it is not carbonized even when the heat-resistant fiber is heated to the fixing temperature.

According to the invention described in claim 3, since the air permeability (JIS L1096 6.27.1) of the seamless belt is ³ to 8 cm ³ / cm ² / sec, the outer surface thereof provided on the thin film The heated air easily moves through a large number of fine vent holes leading to the air, and therefore, the sublimation ink does not sublimate during heating and escapes through the large number of fine vent holes. Since the heat conductivity and heat storage stability during heating of the seamless belt can be sufficiently ensured, the fixing efficiency and the transfer efficiency are further improved.

According to the invention described in claims 7 and 9, (a) a front surface and a back surface formed by garter knitting with yarns made of a large number of heat-resistant fibers on the outer surface of a mirror-processed metal drum A step of extrapolating an annular knitted fabric having a surface layer and a back layer comprising: (b) containing a silicone resin on the outer surface of the outer layer of the annular knitted fabric extrapolated to the outer surface of the metal drum The coating liquid to be applied is applied with a doctor blade so as to have a coating amount of 1.9 to 3.2 kg / m ² , and the coating liquid is impregnated into the yarn composed of the plurality of heat-resistant fibers, and the coating is applied. Forming a coating thin film by a liquid from an outer portion of the back layer of the annular knitted fabric to a portion protruding to the outer surface; (c) the annular knitted fabric coated with the coating solution is formed on the outer surface of the metal drum. 60-70 in the annular knitted fabric in the state of being inserted. And (d) subjecting the annular knitted fabric subjected to the heat drying treatment to a heat curing treatment at 130 to 140 ° C. to form the silicone resin. By curing the heat-resistant fibers, the heat-resistant fibers constituting the yarn are partially adhered with an adhesive composed of a cured silicone resin, and the outer portion of the back layer of the annular knitted fabric is removed from the outside. Forming a thin film composed of a silicone-based resin cured over the portion exposed on the surface, forming a number of fine vents leading to the outer surface of the thin film, and providing a smooth surface on the outer surface of the thin film Since it has the process of forming sequentially, it may meander when rotating around the rollers such as the transfer roller and fixing roller, causing uneven transfer and fixing unevenness, and pattern deviation in the transferred toner image Unnatural Since there is no color pattern or no air permeability, there will be no vapor escape when sublimation ink sublimates during heating, and the ink will not bleed, and the fixing efficiency and transfer efficiency will be further improved. Become.

  Hereinafter, the present embodiment will be described with reference to the drawings.

  FIG. 1 is an enlarged cross-sectional view of a seamless belt showing an embodiment of the present invention. FIG. 2 is an enlarged plan view of a seamless belt showing an embodiment of the present invention. FIG. 3 is an enlarged explanatory view of a garter-knitted annular knitted fabric constituting a seamless belt showing an embodiment of the present invention.

  As shown in FIGS. 1 to 3, the seamless belt 20 of the present invention is formed by garter knitting (pearl knitting) with yarns 1 and 2 made of a large number of heat-resistant fibers. Are reinforced by an annular knitted fabric 7 having a surface layer 3 and a back layer 6 composed of As shown in FIG. 3, in this circular knitted fabric 7, the front surface 3 and the back surface 4 are alternately formed for each course, so that the surface layer 3 composed of the front surface 3 and the back surface 4 is formed. And a back layer 6 composed of the front face 3 and the back face 4. However, in the circular knitted fabric 7, the front surface 3 and the back surface 4 are provisionally determined, and when turned upside down, the front surface 3 becomes the back surface 4, and the back surface 4 becomes the front surface 3. It will be. In the present specification, the front surface 3 and the back surface 4 defined in this way are referred to as a front surface and a back surface. In the present invention, the annular knitted fabric 7 has the surface layer 5 and the back layer 6 constituted by the front surface 3 and the back surface 4, so that it is not wound like a flat knitted fabric. Thus, the flat belt shape can be maintained, and the strength can be improved. For this reason, the seamless belt 20 having the annular knitted fabric 7 has improved shape retention and durability. Become.

  In the seamless belt 20, a large number of heat-resistant fibers constituting the yarns 1 and 2 are partially bonded with an adhesive 8 made of a cured silicone resin. As described above, when a large number of heat-resistant fibers constituting the yarns 1 and 2 are partially bonded with the adhesive 8 made of a cured silicone resin, there is a slight difference between the heat-resistant fibers. Since the deviation is allowed, the portion having the surface layer 5 which is the back portion of the seamless belt 20 has flexibility. Therefore, since the seamless belt 20 having such an annular knitted fabric 7 is superior in flexibility to a conventional seamless belt mainly composed of resin and having an annular woven fabric as a reinforcing material, When rotating around a roller such as a fixing roller, the adhesiveness to the roller is improved and no meandering occurs. Therefore, uneven transfer or uneven fixing does not occur.

  Further, in the seamless belt 20, a thin film 9 made of the cured silicone resin is provided from the outer portion of the back layer 6 of the annular knitted fabric 7 to the portion protruding to the outer surface thereof, A smooth surface 11 is provided on the outer surface of the thin film 9. Thus, the thin film 9 made of the cured silicone resin is provided from the outer part of the back layer 6 of the annular knitted fabric 7 to the part that protrudes to the outer surface thereof. When the smooth surface 11 is provided on the surface, the thin film 9 is reinforced by the annular knitted cloth 7 and is not deformed, and the smoothness of the smooth surface 11 is maintained as it is. The resulting toner image will not be misaligned or an unnatural color pattern will not be formed.

  In the seamless belt 20, the thin film 9 is provided with a number of fine ventilation holes 12 that communicate with the outer surface thereof. As described above, when the thin film 9 is provided with a large number of fine ventilation holes 12 leading to the outer surface, the air heated by the seamless belt 20 can easily move through the fine ventilation holes. The sublimation ink sublimates during heating and escapes through a large number of fine ventilation holes, so that the ink does not bleed, and sufficient heat conductivity and heat storage stability during heating of the seamless belt 20 can be secured. As a result, the fixing efficiency and the transfer efficiency are further improved.

  Therefore, (a) a number of heat-resistant fibers constituting the yarns 1 and 2 are partially bonded with an adhesive made of a cured silicone resin, and (b) the back layer 5 of the annular knitted fabric 7 A thin film 9 composed of the cured silicone resin is provided from the outer part of the thin film 9 to the part exposed on the outer surface thereof. (C) The thin film 9 is provided with a large number of fine vent holes 12 leading to the outer surface. And (d) if the smooth surface 11 is provided on the outer surface of the thin film 9, it causes meandering when rotating around a roller such as a transfer roller or a fixing roller, thereby causing uneven transfer or uneven fixing. Or the transferred toner image may be misaligned, or an unnatural color pattern may be formed, or the air may not breathe and the ink will bleed when the sublimation ink sublimates when heated. There is no Also, an endless belt fixing efficiency and transfer efficiency was further improved can be provided at low cost.

  The heat-resistant fiber is preferably at least one heat-resistant fiber selected from aromatic polyamide-based heat-resistant fiber, fluorine-based resin, polyimide-based resin, carbon-based fiber, and polyarylate fiber. The conductive fiber is not carbonized even when heated to the fixing temperature.

When the air permeability (JIS L1096 6.27.1) of the seamless belt 20 is less than 3 cm ³ / cm ² / sec, the heated air moved through the fine air holes 12 that communicate with the outer surface of the thin film 9. Is insufficient to ensure sufficient thermal conductivity and heat preservation during heating of the seamless belt 20, and the air permeability of the seamless belt 20 (JIS L1096 6.27.1) is When it exceeds 8 cm ³ / cm ² / second, the fine ventilation hole 12 is formed. Therefore, in the present invention, the air permeability (JIS L1096 6.27.1) of the seamless belt 20 is preferably ^{3 to} 8 cm ³ / cm ² / sec. As described above, when the air permeability (JIS L1096 6.27.1) of the seamless belt 20 is ³ to 8 cm ³ / cm ² / sec, the seamless belt 20 is moved through the fine air holes 12 communicating with the outer surface of the thin film 9. Heated air becomes easy to move. For this reason, it is possible to sufficiently ensure the thermal conductivity and heat storage stability of the seamless belt 20 during heating, thereby further improving the fixing efficiency and the transfer efficiency. It becomes.

  The seamless belt 20 of the present invention is preferably a transfer belt having the smooth surface 11 as a transfer surface, an intermediate transfer belt having the smooth surface 11 as a transfer surface, or It is a fixing belt.

The seamless belt 20 of the present invention is
(A) A front surface 3 and a back surface 4 formed by garter knitting (pearl knitting) with yarns 1 and 2 made of a number of heat-resistant fibers on the outer surface of a metal drum (not shown) processed into a mirror surface A step of extrapolating an annular knitted fabric 7 having a surface layer 5 and a back layer 6 composed of
(B) 1.9 to 3.2 kg / m ^{2 of} a coating solution containing a silicone resin on the outer surface of the surface layer 5 of the annular knitted fabric 7 inserted on the outer surface of the metal drum (not shown). Is applied with a doctor blade (not shown) so that the coating amount is less than that, and the coating liquid is impregnated into the yarns 1 and 2 composed of a large number of heat-resistant fibers, and the coating thin film by the coating liquid is applied to the coating film. Forming from the outer part of the back layer 6 of the annular knitted fabric 7 to the part protruding to the outer surface;
(C) In a state where the annular knitted cloth 7 coated with the coating liquid is extrapolated to the outer surface of the metal drum (not shown), the annular knitted cloth 7 is subjected to a heat drying process at 60 to 70 ° C. Applying and drying the solvent of the coating solution, and
(D) A large number of heat-resistant fibers constituting the yarns 1 and 2 by subjecting the annular knitted fabric 7 subjected to the heat drying treatment to a heat curing treatment at 130 to 140 ° C. to cure the silicone resin. Is partially bonded with an adhesive 8 composed of a cured silicone resin, and is cured with a silicone resin cured from the outer portion of the back layer 6 of the annular knitted fabric 7 to the portion exposed to the outer surface. Forming a thin film 9 to be formed, forming a plurality of fine vent holes 12 leading to the outer surface of the thin film 9, and forming a smooth surface 11 on the outer surface of the thin film 9;
Are manufactured sequentially.

  The metal drum processed into a mirror surface used in the step (a) is preferably made of stainless steel, but may be a metal other than stainless steel as long as the object of the present invention is not violated. Further, the metal drum processed into the mirror surface may be coated on the surface with a resin having releasability, for example, a fluororesin. As described above, when the resin having releasability is coated on the surface of the metal drum processed into the mirror surface, the release of the seamless belt is further facilitated.

In the step (b), a coating solution containing a silicone resin is applied to the outer surface of the surface layer 5 of the annular knitted fabric 7 that is extrapolated to the outer surface of the metal drum (not shown). Although applied in .2Kg / m ² of coating amount and becomes as a doctor blade (not shown), thus, the coating amount of 1.9~3.2Kg / m ² a coating solution containing a silicone resin When applied with a doctor blade (not shown), the coating solution is first applied to the surface layer 5 while being handled by the doctor blade, and the yarns 1 and 2 are composed of a number of heat-resistant fibers. Next, it is applied from the outer part of the back layer 6 to the outer surface of the back layer 6 and applied to the surface of the mirror-finished metal drum to form a coating thin film by the coating solution. When the coating amount of the coating solution is less than 1.9 Kg / m ² , the coating film becomes too small to form the coating film, and the coating amount of the coating solution exceeds 3.2 Kg / m ² . In this case, the coating film is formed on the entire surface, so that the thin film 9 is difficult to be formed, and the fine ventilation holes 12 are not easily formed. Therefore, in the present invention, the coating amount of the coating solution is preferably 1.9 to 3.2 Kg / m ² .

  In the step (c), the annular knitted fabric 7 coated with the coating liquid is placed on the outer surface of the metal drum (not shown) while being inserted into the annular knitted fabric 7 at 60 to 70 ° C. The annular knitted cloth 7 coated with the coating liquid is subjected to a heat drying process at 60 to 70 ° C. in a state where the annular knitted cloth 7 is extrapolated to the outer surface of the metal drum. Then, the coating film is dried while being in contact with the surface of the metal drum processed into a mirror surface, so that the surface of the coating film in contact with the surface of the metal drum is a smooth surface.

  In the step (d), the annular knitted fabric 7 that has been subjected to the heat drying treatment is subjected to a heat curing treatment at 130 to 140 ° C. to cure the silicone-based resin. When heat-curing treatment is performed on the applied circular knitted fabric 7 at 130 to 140 ° C., a large number of heat-resistant fibers constituting the yarns 1 and 2 are partially formed with an adhesive 8 composed of a cured silicone resin. The thin film 9 made of a cured silicone resin is formed from the outer portion of the back layer 6 of the annular knitted fabric 7 to the portion that protrudes to the outer surface. A large number of fine ventilation holes 12 communicating with the outer surface of the thin film 9 are formed in the thin film 9, and a smooth surface 11 is formed on the outer surface of the thin film 9.

  Therefore, when the step (a), the step (b), the step (c), and the step (d) are sequentially provided, the rollers such as the transfer roller and the fixing roller are rotated. Vapor when sublimation ink sublimates during heating due to meandering causing uneven transfer or fixing, transferred toner image with pattern deviation or unnatural color pattern, or lack of air permeability Thus, the endless belt can be provided at a low cost without causing the ink to bleed and the ink from bleeding, and further improving the fixing efficiency and the transfer efficiency.

Example 1
(A) A yarn composed of a large number of meta-type polyamide-based heat-resistant fibers (manufactured by Teijin Ltd., Conex SF HT) is knitted with a garter knitting machine (manufactured by Shima Seiki Co., Ltd., SWG-X) to a thickness of 1.5 mm , A process of extrapolating the outer knitted fabric with a circumferential length of 1300 mm to the outer surface of a metal drum made of stainless steel with a circumferential length of 1830 mm processed into a mirror surface,
(B) 18.88 WET% silicone resin (Shin-Etsu Chemical Co., Ltd., KE-1950-70A), silicone resin (Shin-Etsu) on the outer surface of the surface layer of the annular knitted fabric extrapolated to the outer surface of the metal drum (Chemical Industry, KE-1950-70B) 18.88 WET%, silicon dioxide (Aerosil # 200, Aerosil # 200) 1.50 WET% and toluene 60.75 WET% coating solution 1.5Kg / m The coating is applied with a doctor blade so that the coating amount is ² , and the coating liquid is impregnated into the yarn composed of the plurality of heat-resistant fibers, and the coating thin film by the coating liquid is applied from the outer portion of the annular knitted fabric. Forming over the outer surface of the part,
(C) In a state where the annular knitted fabric coated with the coating liquid is extrapolated to the outer surface of the metal drum, the annular knitted fabric is subjected to a heat drying treatment at 60 to 70 ° C. Drying the solvent, and
(D) A number of heat-resistant fibers constituting the yarn were cured by subjecting the heat-dried annular knitted fabric to heat curing at 130 IS 140 ° C. to cure the silicone resin. A thin film composed of a silicone resin cured from the outer portion of the back layer of the annular knitted fabric to the portion exposed to the outer surface is formed while being partially adhered with an adhesive composed of a silicone resin. A seamless belt was obtained by sequentially forming a large number of fine ventilation holes on the outer surface of the thin film and forming a smooth surface on the outer surface of the thin film.

(Example 2)
A seamless belt was obtained in the same manner as in Example 1 except that, in (b), the coating solution was applied with a doctor blade so that the coating amount was 2 kg / m ² .

(Example 3)
A seamless belt was obtained in the same manner as in Example 1 except that, in (b), the coating solution was applied with a doctor blade so that the coating amount was 2.5 kg / m ² .

Example 4
A seamless belt was obtained in the same manner as in Example 1 except that, in (b), the coating solution was applied with a doctor blade so that the coating amount was 3 kg / m ² .

1 is an enlarged cross-sectional view of a seamless belt showing an embodiment of the present invention. It is an enlarged plan view of a seamless belt showing an embodiment of the present invention. FIG. 3 is an enlarged explanatory view of a garter-knitted annular knitted fabric constituting a seamless belt showing an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Yarn 3 Front surface 4 Back surface 5 Surface layer 6 Back layer 7 Circular knitted fabric 8 Adhesive 9 Thin film 11 Smooth surface 12 Fine ventilation hole 20 Seamless belt

Claims (9)

In a seamless belt reinforced with an annular knitted fabric, which is formed by garter knitting with yarns composed of a large number of heat-resistant fibers, and has a surface layer and a back layer composed of a front surface and a back surface,
(A) A number of heat-resistant fibers constituting the yarn are partially bonded with a cured silicone resin,
(B) A thin film made of the cured silicone resin is provided from the outer part of the back layer of the annular knitted fabric to the part that protrudes to the outer surface,
(C) the thin film is provided with a number of fine vents leading to its outer surface; and
(D) A seamless belt characterized in that a smooth surface is provided on the outer surface of the thin film.   The heat-resistant fiber is at least one heat-resistant fiber selected from an aromatic polyamide-based heat-resistant fiber, a fluorine-based resin, a polyimide-based resin, a carbon-based fiber, and a polyarylate fiber. The seamless belt according to 1. The seamless belt of the air permeability (JIS L1096 6.27.1) is, seamless belt according to claim 1 or 2, characterized in that a 3~8cm ³ / cm ² / sec.   The seamless belt according to any one of claims 1 to 3, wherein the seamless belt is a transfer belt having the smooth surface as a transfer surface.   The seamless belt according to any one of claims 1 to 3, wherein the seamless belt is an intermediate transfer belt having the smooth surface as a transfer surface.   The seamless belt according to any one of claims 1 to 3, wherein the seamless belt is a fixing belt. (A) An annular knitting having a surface layer and a back layer composed of a front surface and a back surface, which are formed by garter knitting with yarns made of a large number of heat-resistant fibers on the outer surface of a metal drum processed into a mirror surface Extrapolating the cloth,
(B) A coating liquid containing a silicone resin is applied to the outer surface of the surface layer of the annular knitted fabric extrapolated to the outer surface of the metal drum so as to have a coating amount of 1.9 to 3.2 Kg / m ^2. Applying with a doctor blade, the coating liquid is impregnated into a yarn composed of a large number of heat-resistant fibers, and a coating thin film by the coating liquid is exposed from the outer portion of the back layer of the annular knitted fabric to the outer surface thereof. Forming over the part,
(C) In a state where the annular knitted fabric coated with the coating liquid is extrapolated to the outer surface of the metal drum, the annular knitted fabric is subjected to a heat drying treatment at 60 to 70 ° C. Drying the solvent, and
(D) A number of heat-resistant fibers constituting the yarn were cured by subjecting the heat-dried annular knitted fabric to a heat-curing treatment at 130 to 140 ° C. to cure the silicone resin. It is composed of a silicone resin that is partially bonded with a silicone resin and cured from the outer portion of the back layer of the annular knitted fabric facing the outer surface of the metal drum to the portion that protrudes to the outer surface. A method for producing a seamless belt comprising the steps of forming a thin film, forming a plurality of fine vent holes leading to the outer surface of the thin film, and forming a smooth surface on the outer surface of the thin film. .   The heat-resistant fiber is at least one heat-resistant fiber selected from an aromatic polyamide-based heat-resistant fiber, a fluorine-based resin, a polyimide-based resin, a carbon-based fiber, and a polyarylate fiber. The method for producing a seamless belt according to claim 7.   The coating solution containing the silicone resin contains 4 to 6 parts by weight of a silicone resin, 0.5 to 1 part by weight of an inorganic filler, and 3 to 5 parts by weight of a solvent. The method for producing a seamless belt according to 7 or 8.

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