JPH11327347A - Cleaning sheet, cleaning material and cleaning device, for fixing roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning sheet, cleaning material and a cleaning device for fixing roll capable of excellently sweeping off unfixed toner, uniformly grinding the toner and the fixing roll surface without deeply scratching the fixing roll surface, satisfactorily holding swept toner, and easy to manufacture. SOLUTION: To this cleaning sheet for fixing roll, an oil is stuck to a fiber sheet, and powders are held by the oil. In this cleaning material for fixing roll, one end of the above cleaning sheet for the fixing roll is wound round a shaft, and the other end of the cleaning sheet for the fixing roll is fixed onto another shaft. This cleaning device for fixing roll is provided with a mechanism capable of unwinding the cleaning sheet for the fixing roll, holding the cleaning sheet in press contact with the fixing roll by pressurizing means, and thereafter, winding up the cleaning sheet for the fixing roll.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing roll cleaning sheet, a fixing roll cleaning material, and a fixing roll cleaning device.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic apparatus such as a copying machine, a laser beam printer, and a facsimile, a copying sheet such as paper carrying an unfixed toner image is passed between a fixing roll and a pressure roll to heat and heat. By the action of pressure,
The toner was fixed on the copy sheet surface. for that reason,
The toner is transferred to the surface of the fixing roll and / or the pressure roll, and the toner is transferred again to the trailing edge of the copy sheet or to the next copy sheet passing therethrough, causing a problem that the copy sheet is stained (so-called offset). .

[0003] In particular, recently developed color copying machines have been in a state of being easily offset due to the following reasons (1) to (5). (1) Since a plurality of types of toners are used, the amount of unfixed toner is much larger than the amount of unfixed toner in a conventional monochrome copying machine. (2) Since a toner having a low softening temperature and a narrow melting temperature range is often used, the cohesive force of the toner tends to be insufficient. As a result, the toner layer is easily broken. (3) Wax is mixed into the toner to improve the releasability, but since the melting point of the wax is high, a large amount of wax cannot be mixed because the toner is melted at a low temperature. (4) To enable faster copying, it is necessary to increase the rotation speed of the fixing roll and the pressure roll. (5) If oil adheres to the surface of the image formed on the copy sheet, there is a problem that the image is deteriorated, sticky, or cannot be rewritten, and the amount of oil to be applied tends to be reduced.

In order to solve such an offset problem, various fiber sheets are brought into contact with the surface of a fixing roll,
Unfixed toner was removed. For example, (1) a fiber sheet containing metal-plated fibers, and (2) a fiber sheet obtained by applying metal plating to a fiber sheet have been proposed. However, the fiber sheet containing the metal-plated fiber of (1)
The ratio of metal-plated fibers is low, such as the need to mix with adhesive fibers to form a fiber sheet,
In addition, it is difficult to uniformly disperse the metal-plated fibers throughout the fiber sheet, so that the unfixed toner has poor wiping properties. On the other hand, (2) in the case where the metal sheet is applied to the fiber sheet, the plating thickness tends to vary, that is, the plating thickness at the intersection of the fibers becomes thicker, and that portion is larger than the portion other than the intersection between the fibers. There was a tendency to be hard. As a result, deep flaws are partially generated on the surface of the fixing roll, thereby significantly reducing image quality and shortening the service life of the fixing roll.

[0005] Further, (3) a fiber sheet containing fibers into which abrasive grains are kneaded, and (4) a fiber sheet in which abrasive grains are fixed by a binder, have been proposed. However, the fiber sheet containing the fibers into which the abrasive grains are kneaded (3) has a poor wiping property of the unfixed toner because the amount of the abrasive grains exposed on the fiber surface is small. Further, since the strength of the fiber is reduced by kneading the abrasive grains, the possibility of breaking during use cannot be denied. On the other hand, (4) the fiber sheet in which the abrasive grains are fixed by the binder is one of the effective means for preventing the offset, but the abrasive grains are firmly fixed and the dispersibility of the abrasive grains becomes non-uniform. Abrasive grains tend to concentrate at the intersections of the fibers. Therefore, it is necessary to use abrasive grains having a relatively small particle diameter and to control the particle diameter to be uniform so that deep flaws are not partially generated on the fixing roll surface. An extremely difficult coating technique was required to make the state of adhesion of the abrasive grains in the same state as the state of adhesion at the intersection of the fibers.
Further, if abrasive particles having a relatively small particle diameter are fixed with a binder, the voids in the fiber sheet are filled, and it is difficult to hold the wiped toner. Therefore, there is a problem that the amount of the fiber sheet used must be increased so as to hold the toner.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is excellent in wiping off unfixed toner. An object of the present invention is to provide a fixing roll cleaning sheet, a fixing roll cleaning material, and a fixing roll cleaning device that can uniformly grind the surface and are excellent in holding the wiped toner and that are easy to manufacture. I do.

[0007]

The fixing roll cleaning sheet of the present invention (hereinafter simply referred to as "cleaning sheet")
No.) is an oil in which oil adheres to the fiber sheet, and the powder is held by the oil. Thus, since the cleaning sheet of the present invention contains powder,
Excellent toner wiping properties. Further, since the powder is in a state of high degree of freedom held by the oil, when the cleaning sheet is pressed against the surface of the fixing roll, no deep scratch is generated on the surface of the fixing roll. In addition,
Since the powder is not kneaded into the fiber and the strength of the fiber does not decrease, it does not break during use. Further, since the oil is transferred to the fixing roll and the toner can be held in the gap where the oil was present, the holding property of the wiped toner is excellent. Furthermore, since the powder is held by the oil and the powder can be uniformly dispersed, it can be easily manufactured.

[0008] In the cleaning material for fixing roll of the present invention, one end of the cleaning sheet for fixing roll is wound around a shaft, and the other end of the cleaning sheet for fixing roll is fixed to another shaft. . For this reason, a new cleaning sheet can always be brought into contact with the surface of the fixing roll, and the toner can be easily wiped off.

The fixing roll cleaning device of the present invention unwinds the fixing roll cleaning sheet from the fixing roll cleaning material, and presses the fixing roll cleaning sheet against the fixing roll by pressing means. It has a mechanism for winding up the cleaning sheet. For this reason, a new cleaning sheet can always be brought into contact with the surface of the fixing roll, and the toner can be easily wiped off.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The fiber sheet constituting the cleaning sheet of the present invention may be a woven fabric, a knitted fabric, a nonwoven fabric, or a composite thereof. Among these, non-woven fabrics that are excellent in oil and powder retention and toner wiping and retention due to micropores formed by the three-dimensional arrangement of fibers are included. preferable.

[0011] The fiber sheet of the present invention preferably contains heat-resistant fibers for contact with a high-temperature fixing roll. Examples of the heat-resistant fiber include meta-type or para-type aromatic polyamide fibers, polyamide-imide fibers, polytetrafluoroethylene fibers, aromatic polyetheramide fibers,
One or more kinds of polybenzimidazole fiber, polyphenylene sulfide fiber, aromatic polyester fiber and the like can be used. Among these, aromatic polyamide fibers can be suitably used because they have excellent wiping properties of the toner and hardly shrink.

[0012] The heat-resistant fiber is preferably contained in the fiber sheet in an amount of 10 mass% or more so that the cleaning sheet does not break even when the cleaning sheet comes into contact with the fixing roll.
More preferably, it is contained in an amount of 20 mass% or more. In addition, since it is preferable to contain an adhesive fiber so as to be excellent in form stability, the content is preferably 80 mass% or less.

[0013] The heat-resistant fiber preferably has an average fiber diameter of 20 µm or less, more preferably 15 µm or less, so that the heat-resistant fiber has excellent oil and powder holding properties. Although the lower limit is not particularly limited, about 5 μm is appropriate. When the cross-sectional shape of the heat-resistant fiber is non-circular, the diameter of a circle having the same area as the cross-sectional area is regarded as the fiber diameter.

[0014] The fiber sheet of the present invention, in addition to the above heat-resistant fiber,
It preferably contains adhesive fibers that can bond between the fibers. As the adhesive fiber, for example, undrawn polyethylene terephthalate fiber, undrawn polybutylene terephthalate fiber, undrawn polyphenylene sulfide fiber,
Nylon undrawn fibers such as 6 nylon and 66 nylon can be used. Among these, unstretched polyethylene terephthalate fiber (1) has a high melting point of 255 ° C., does not decrease the adhesive force even when it comes into contact with a fixing roll, does not break the cleaning sheet, and (2) has a relatively high temperature at the time of bonding. It is easy to manufacture because of the low temperature and wide bonding temperature range.
Therefore, it can be suitably used.

[0015] This adhesive fiber has excellent shape stability,
The fiber sheet preferably contains 20% by mass or more, more preferably 30% by mass or more. Further, in order to prevent heat resistance from being lowered, the content is preferably 90 mass% or less in the fiber sheet, and is preferably 80 mass% or less.
More preferably, it is ss% or less.

In the fiber sheet of the present invention, in addition to the heat-resistant fiber and the adhesive fiber, a fiber softened by the heat of the fixing roll (hereinafter, referred to as a "softened fiber") can be mixed. By mixing this softened fiber, the thickness of the fiber sheet can be reduced when it comes into contact with the fixing roll, so that a large amount of oil can be applied to the surface of the fixing roll. In addition, the softening deformation of the softening fibers increases the contact area between the cleaning sheet and the fixing roll, and also has the effect of making it difficult to damage the fixing roll.

Examples of the softened fibers include polyamide fibers such as 6 nylon fibers and 66 nylon fibers, polyester fibers such as drawn polyethylene terephthalate fibers and drawn polybutylene terephthalate fibers, acrylic fibers, vinylon fibers, and drawn polyphenylene. Sulfide fiber or the like can be used. Among them, the drawn polyethylene terephthalate fiber has a high melting point of about 255 ° C. and is hardly softened and melted at the ambient temperature of the fixing roll installation location, so that it can be suitably used. In addition, the above-mentioned adhesive fiber may act as a softening fiber in some cases. This softened fiber can be contained in the fiber sheet at 0 to 60 mass%.

The cross-sectional shape of the fibers constituting the fiber sheet of the present invention need not be circular, but may be polygonal (for example, triangular,
Squares, etc.) and alphabet shapes (eg, Y shape,
Non-circular shape such as X shape). When the cross-sectional shape of the heat-resistant fiber is non-circular, it is excellent in oil and powder retention and toner wiping and retention.

[0019] The fiber sheet of the present invention is preferably bonded with adhesive fibers, and is preferably bonded over the entire surface so as to have excellent form stability. Due to the entire surface being adhered, shrinkage hardly occurs upon contact with the fixing roll, and oil unevenness hardly occurs.

The surface density and thickness of the fiber sheet of the present invention are not particularly limited, but the surface density is 10 to 60 g / m 2.
It is preferably ² , and the thickness is preferably from 20 to 120 µm, more preferably from 30 to 100 µm.

In the cleaning sheet of the present invention, oil adheres to the above-described fiber sheet. This oil is transferred to the fixing roll, and has the effect of improving the releasability of the toner remaining on the surface of the fixing roll and the effect of holding the powder. In addition, the powder is easily dispersed uniformly by the oil, and the powder is hard to agglomerate.
Also has the effect.

Examples of the oil include methyl silicone oil, dimethyl silicone oil, ethyl silicone oil, phenyl silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, mercapto-modified silicone oil, 3,3,3-trifluoropropyl A silicone oil such as a silicone oil can be used alone or as a mixture. Among these, dimethyl silicone oil is suitable for use because of its excellent toner releasability.

The amount of oil adhesion depends on the thickness of the fiber sheet, etc.
Therefore, although different, 100 g / m ^TwoPreferably
No. In addition, the viscosity of the oil is
1 to improve the powder retention and powder retention.
Preferably between 0 and 30,000 centistokes
No.

[0024] The cleaning sheet of the present invention further contains a powder, which is held by oil and has a high degree of freedom. In addition to the effect of improving the wiping property of the toner remaining on the fixing roll surface, this powder also has the effect of increasing the viscosity of the oil and preventing the oil drop from occurring before the cleaning sheet comes into contact with the fixing roll surface. . Therefore, low-viscosity oil having excellent diffusibility can be applied to the surface of the fixing roll without causing oil drops.

Examples of the powder include inorganic powders (eg, feldspar, magnesia, diatomaceous earth, silica, silica alumina, mullite, alumina, aluminum hydroxide, zircon, zirconia, titanium oxide, magnesia, calcium oxide, Calcium silicate, magnesium silicate, shirasu, shirasu balloon, perlite, glass, glass balloon, dolomite, chamotte, mica, cordierite, silicon nitride, boron nitride, silicon carbide, boron carbide, metal powder, carbon powder And its colloidal powder, organic powder that does not melt at a temperature of 170 ° C. or less (nylon, polyester, acrylic, vinylon, polyvinyl chloride, polyurethane, polytetrafluoroethylene, meta-type or para-type aromatic polyamide, Polyamide imide, polytetrafluoro Ethylene, aromatic polyetheramide, polybenzimidazole, polyphenylene sulfide, aromatic polyester, etc.). Among them, silica and alumina can be preferably used because they are chemically stable, the particle size is easily adjusted, the hardness is excellent in polishing power, and the cost is low.

The average particle size of the powder is preferably 0.2 to 15 μm. If the average particle size of the powder is less than 0.2 μm, the dispersibility in oil tends to be poor, and if the average particle size exceeds 15 μm, the surface area tends to be small and the polishing power tends to be poor. And more preferably 1 to
7 μm. The average particle size is JISR 60
It refers to a value measured by a fine powder enlarged photograph test method specified in 02 (test method of particle size of abrasive).

It is preferable that the powder has a mass ratio to the oil (100) of 3 to 25 mass%. 3ma
If it is less than ss%, the wiping properties of the toner tend to decrease, and if it exceeds 25 mass%, the powder is likely to agglomerate and the surface of the fixing roll may be seriously damaged. 5 to 20 mass%.

Further, although the shape of the powder is not particularly limited, the non-spherical shape makes it easier to wipe off the toner.
It can be suitably used.

Next, a brief description will be given of a method of manufacturing a cleaning sheet in which oil and powder adhere to a nonwoven fabric suitable as a fiber sheet.

First, a fiber web containing the above-described heat-resistant fiber and adhesive fiber (preferably including softened fiber) is formed. As a method of forming the fiber web, for example, there are a dry method such as a card method and an air lay method, and a wet method.
Among them, it is preferable to orient the fibers in the length direction of the fiber web by the card method because the strength in the length direction of the cleaning sheet can be increased and the cleaning sheet is not easily broken when used. . The fiber web need not be a single layer, and two or more fiber webs of the same type or different types may be laminated.

Next, a nonwoven fabric can be produced by bonding the adhesive fibers constituting the fiber web.
The bonding of the adhesive fibers can be performed, for example, by passing the fiber web between hot calender rolls or by using a flat plate press. The former method is preferable because it is excellent in continuous production. The preferred conditions for passing between the heat calenders are as follows: a temperature of 170 to 250 ° C. and a linear pressure of 98 to 980 N / cm are preferable so that the adhesive can be firmly bonded and the thickness can be adjusted. It is more preferable to carry out at a temperature of 190 to 230 ° C. and a linear pressure of 294 to 686 N / cm.

On the other hand, a dispersion solution in which powder is dispersed in oil as described above is prepared. The powder is oil (100)
It is preferable to mix by 3 to 25 mass% in terms of mass ratio to the above.

Then, the cleaning sheet of the present invention can be produced by immersing the nonwoven fabric produced by the above-mentioned method in a dispersion solution or spraying or coating the nonwoven fabric with the dispersion solution. In order to adjust the amount of oil or powder, the dispersion solution may be applied to a nonwoven fabric and then passed between rolls.

[0034] In the cleaning material of the present invention, one end of the cleaning sheet as described above has a shaft (unwinding shaft).
, And the other end of the cleaning sheet is fixed to another shaft (winding shaft). Therefore, the cleaning material of the present invention can always bring a new cleaning sheet into contact with the fixing roll by sequentially unwinding the cleaning sheet from the unwinding shaft, and thus has excellent toner wiping properties and oil application properties.

The method for fixing the cleaning sheet to the shaft includes, for example, (1) fixing with a double-sided tape,
(2) fixing with an adhesive resin such as a hot melt resin,
(3) When the shaft is made of a thermoplastic resin, fixing by thermal bonding with a cleaning sheet; (4) Fixing by installing a pin or the like on the shaft and inserting the cleaning sheet; (5) Forming a groove in the shaft And fixing by inserting a cleaning sheet into the groove. In the case of fixing by the above methods (1) to (3), the shaft may be fixed to the entire surface of the shaft or may be partially fixed. Further, on the unwinding shaft side, the cleaning sheet does not necessarily have to be fixed, but may be simply wound on the shaft.

The cleaning device of the present invention has a mechanism for unwinding a cleaning sheet from the above-described cleaning material, pressing the cleaning sheet against a fixing roll by pressing means, and then winding the cleaning sheet. Therefore, the cleaning device of the present invention can always bring a new cleaning sheet into contact with the fixing roll by sequentially unwinding the cleaning sheet from the unwinding shaft, and thus has excellent toner wiping properties and oil application properties.

As a means for pressing the cleaning sheet of the cleaning device of the present invention to the fixing roll, for example, the cross section is circular or polygonal (for example, square or hexagonal).
Can be used. Among these, a rod-shaped body having a circular cross section is preferable because the cleaning sheet can be uniformly pressed to the fixing roll. Since this rod-shaped body preferably has excellent elasticity and heat resistance, it is preferably made of, for example, foamed or non-foamed silicone rubber. The pressing force applied to the fixing roll by the rod is such that an action width (nip width) between the rod and the fixing roll surface is 2 to 5 m so that the toner can be easily wiped off.
Preferably, the pressing force is m.

[0038] In the cleaning device of the present invention,
Since the cleaning sheet containing the powder is used, the possibility that the powder falls off and adheres to the fixing roll surface cannot be completely denied. Therefore, it is preferable to install the felt or the roll so that the felt or the roll can come into contact with the surface of the fixing roll after passing through the cleaning device so as to remove such dropped powder.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[0040]

(Example 1) Meta-type aromatic polyamide fiber (fiber diameter 12.3 μm, fiber length 51 mm, circular cross section) 5
0 mass%, drawn polyethylene terephthalate fiber (12.3 μm, fiber length 51, circular cross section) 10 mass
%, Undrawn polyethylene terephthalate fiber (22.6
μm, a fiber length of 51, and a circular cross section of 40 mass%), and opened by a carding machine to form a unidirectional fiber web in which the fibers were oriented in the length direction of the fiber web.

Next, the unidirectional fiber web was heated at a temperature of 21.
0 ° C between steel roll and cotton roll (linear pressure 3
92 N / cm), and the entire surface was bonded with undrawn polyethylene terephthalate fibers to produce a nonwoven fabric having an areal density of 26 g / m ² and a thickness of 55 μm.

On the other hand, dimethyl silicone oil (viscosity 300
cs), an alumina powder (non-spherical) having an average particle diameter of 2 μm was added to dimethyl silicone oil by 10 mass
% And stirred to prepare a dispersion liquid that was uniformly dispersed.

Next, after immersing the nonwoven fabric in the dispersion, excess oil and powder were removed between rolls to produce a cleaning sheet to which 20 g / m ^{2 of} oil and powder had adhered.

Comparative Example 1 A nonwoven fabric formed in the same manner as in Example 1 was subjected to nickel plating (3 g / m ² ) on the fiber surface by a conventional electroless plating method. Then, this nickel-plated nonwoven fabric was treated with dimethyl silicone oil (viscosity 30).
After immersion in 0 cs), excess oil was removed between the rolls to produce a cleaning sheet to which 20 g / m ^{2 of} oil had adhered.

(Comparative Example 2) A nonwoven fabric formed in the same manner as in Example 1 was immersed in dimethyl silicone oil (viscosity: 300 cs), and excess oil was removed between rolls to deposit 20 g / m ^{2 of} oil. A cleaning sheet was manufactured.

(Evaluation method of cleaning sheet)
A color copier including a fixing roll made of V silicone rubber (1 mm thick) and a pressure roll made of RTV silicone rubber (2 mm thick), both of which rolls have a fixing device with a built-in heater. Was prepared.

Next, the cleaning sheets of Examples and Comparative Examples 1 and 2 are supplied so as to move in the directions opposite to the rotation direction of the fixing roll, respectively, and supplied by a pressing member made of a columnar foamed silicone rubber. The pressed cleaning sheet is pressed against the fixing roll (nip width 3 mm, pressing force 0.
(05 kg / cm).

Then, the photograph was continuously copied, and the occurrence of the offset was visually observed with respect to the copied image. In addition, each time 10,000 copies were made, it was visually observed whether or not a deep streak was formed on the surface of the fixing roll. The results are shown in Table 1. From Table 1, it can be seen that the cleaning sheet of the present invention has excellent wiping properties and does not cause deep damage to the fixing roll.

[0049]

【table 1】

[0050]

The cleaning sheet for a fixing roll of the present invention (hereinafter, simply referred to as "cleaning sheet") is one in which oil adheres to a fiber sheet, and powder is held by the oil. Thus, since the cleaning sheet of the present invention contains powder, it is excellent in toner wiping properties. Further, since the powder is in a state of high degree of freedom held by the oil, when the cleaning sheet is pressed against the surface of the fixing roll, no deep scratch is generated on the surface of the fixing roll. In addition, the powder is not kneaded into the fibers, and the strength of the fibers does not decrease, so that the fibers do not break during use. Further, since the oil is transferred to the fixing roll and the toner can be held in the gap where the oil was present, the holding property of the wiped toner is excellent. Furthermore, since the powder is held by the oil and the powder can be uniformly dispersed, it can be easily manufactured.

The fixing roll cleaning material of the present invention is such that one end of the fixing roll cleaning sheet is wound around a shaft, and the other end of the fixing roll cleaning sheet is fixed to another shaft. . For this reason, a new cleaning sheet can always be brought into contact with the surface of the fixing roll, and the toner can be easily wiped off.

The fixing roll cleaning device of the present invention unwinds the fixing roll cleaning sheet from the fixing roll cleaning material, and presses the fixing roll cleaning sheet against the fixing roll by pressing means. It has a mechanism for winding up the cleaning sheet. For this reason, a new cleaning sheet can always be brought into contact with the surface of the fixing roll, and the toner can be easily wiped off.

Claims (3)

[Claims] 1. A cleaning sheet for a fixing roll, wherein oil adheres to a fiber sheet, and a powder is held by the oil. 2. The fixing roll according to claim 1, wherein one end of the fixing roll cleaning sheet is wound around a shaft, and the other end of the fixing roll cleaning sheet is fixed to another shaft. Cleaning material for rolls. 3. A fixing roll cleaning sheet is unwound from the fixing roll cleaning material according to claim 2,
A fixing roll cleaning device, comprising: a mechanism for pressing the fixing roll cleaning sheet against the fixing roll by pressing means, and then winding up the fixing roll cleaning sheet.