JPH11352802A - Transfer/conveyor belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer/conveyor belt where the wear of a belt surface is suppressed by a two-layer structure and also the occurrence of crack is prevented. SOLUTION: As for the transfer/conveyor belt used for a mechanism which feeds a transfer material to a transfer area and is provided with a cleaning means for removing stuck toner by sliding and having the two-layer structure where a wear resistant layer 12 is laminated on the surface of the belt main body 11 of a side on which the transfer material is placed, the thickness of the wear resistant layer 12 is set to be 1.0-15.0 μm, and also the surface roughness of the surface of the belt main body 11 where the wear resistant layer is laminated is set to be 1.8-15.0 μm, and the surface roughness of the wear resistant layer 12 is set to be 1.8-9.3 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer belt used in a transfer area of a copying machine, a printer, a facsimile or the like.

[0002]

2. Description of the Related Art In recent years,
As the speed of OA equipment such as copiers, printers, and facsimile machines has increased, belt transfer methods have come to be used in order to reliably transfer a transfer material such as paper and hold a toner image.

[0003] Here, the belt transfer system is, for example, as shown in FIG.
As shown in FIG. 1, the back surface of the endless transfer / transport belt 1 is charged by the transfer charger 2 (negatively charged in FIG. 1).
The transfer material (generally paper) 4 conveyed from the paper feed roller 3 is electrostatically attracted and conveyed to the transfer area by the charged charges, and the toner image formed on the photosensitive drum 5 in the transfer area is transferred to the transfer material 4.
Is transferred to the fixing roller 6 after being transferred to the fixing roller 6. In FIG. 1, reference numeral 7 denotes a drive roller for rotating the transfer / conveyance belt 1 in the direction of the arrow.

[0004] Such a belt transfer system is excellent in that transfer and paper transfer can be performed at the same time, but the toner adhering to the photosensitive drum 5 is not only transferred to the transfer material 4 but also to the transfer convey belt. 1 will also be adsorbed. The toner adsorbed on the transfer / conveyance belt adheres to the newly conveyed transfer material 4 and causes back contamination of the transfer material 4.
In particular, in the case of double-sided copying, the image formed on the back surface is stained or deteriorated. Therefore, in order to prevent the transfer material 4 from being stained on the back, a cleaning means 10 such as a blade or a brush is provided.

However, cleaning with a brush, a blade, or the like removes toner adhering to the belt 1 by sliding the cleaning means 10 against the surface of the transfer belt 1.
There is a problem of so-called abrasion, which causes wear and weight loss. The wear of the transfer conveyance belt 1 not only shortens the life of the transfer conveyance belt 1 but also causes the misalignment of the belt 1 to cause misalignment of the electrostatic attraction of the transfer material, which is transferred. Or cause image shift. For this reason, studies have been made on transfer conveyance belts having good cleaning performance.

The above problem is not limited to the case where the transfer / transport belt itself is charged. For example, as shown in FIG. 2, the transfer material 4 is transported to the transfer area, and the transfer charger 2 'is transferred to the transfer area. The transfer material 4 is charged with the photosensitive drum 5
The same applies to the transfer / conveyance belt 1 'used in the mechanism for transferring the toner image formed on the transfer belt. That is,
The transfer conveyance belt 1 'in such a mechanism is composed of a transfer material 4
Although the toner is not charged because it is used only as a means for transporting the toner, the toner adhering to the photosensitive drum 5 physically falls onto the belt 1 in many cases. Therefore, as in the case of the belt transfer method in which the belt 1 itself is charged, the cleaning unit 1 for removing the toner attached to the surface of the belt 1 is used.
In many cases, the belt 1 and the cleaning means 10 are rubbed with each other.

In order to solve the problem of wear of the transfer conveyance belt, it is conceivable to coat the belt surface with a material having good slipperiness, for example, a fluororesin-based material, or to use a hard material having excellent wear resistance. Can be On the other hand, since it is necessary to secure the tension as the transport belt, a transfer transport belt in which the belt main body is formed of an elastic body such as rubber and the above-described fluororesin-based material or hard material is laminated thereon is generally used. However, such a configuration has a problem in that the elasticity of the rubber body and the hardness of the surface portion are inconsistent, and cracks are generated in the surface portion.

Japanese Patent Application Laid-Open No. Hei 8-1 discloses a transfer / transport belt in which the occurrence of cracks is prevented while preventing wear of the belt surface.
Japanese Patent No. 60766 discloses that an inner layer is made of an elastic material to secure a tension as a conveyor belt, a surface to be cleaned (a surface layer) is made of a hard material having low friction, and a gap between the inner layer and the surface layer is formed. There has been proposed a transfer / transport belt having a three-layer structure in which an intermediate layer having a greater elongation than the surface layer is interposed. This transfer conveyance belt prevents an occurrence of cracks in the surface layer by interposing an intermediate layer having a larger elongation than the surface layer, and even if a crack occurs in the surface layer, the cracks are formed on the inner layer. Is prevented.

However, such a three-layer structure is complicated, and the surface layer is formed after the formation of the intermediate layer, so that the productivity is poor and the cost is increased. In particular, a transfer conveyance belt used for an inexpensive copying machine or the like which does not charge the belt itself is not profitable and cannot be applied.

The present invention has been made in view of such circumstances, and has a two-layer structure that suppresses abrasion of the belt surface,
In addition, it is an object of the present invention to provide a transfer / transport belt that can prevent the occurrence of cracks.

[0011]

The inventor of the present invention has determined that the surface roughness of the belt contributes to toner adhesion and releasability, and the surface roughness of the belt body contributes to abrasion and elongation of the belt surface. The present invention has been completed.

That is, the transfer / transport belt of the present invention is a transfer / transport belt used for a mechanism provided with a cleaning means for transporting a transfer material to a transfer area and removing adhered toner by rubbing. In a transfer transport belt having a two-layer structure in which a wear-resistant layer is laminated on a surface on which a transfer material is placed, the wear-resistant layer has a thickness of 1.
0 to 15.0 μm, the surface roughness of the surface of the belt body on which the wear-resistant layer is laminated is 1.8 to 15.0 μm, and the surface roughness of the wear-resistant layer is 1.8 to 9 .3 μm.

The surface roughness (Rz (main body)) of the surface of the belt body on which the wear-resistant layer is laminated is equal to or greater than the surface roughness (Rz (wear-resistant layer)) of the resin wear-resistant layer. Rz
(Abrasion resistant layer) ≦ Rz (body)).
Further, the belt main body is preferably made of vulcanized rubber, and the abrasion-resistant layer is preferably made of a water-based urethane resin containing a fluorinated resin.

The surface roughness (Rz) referred to here is JIS
It refers to the ten-point average roughness specified in B601.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A transfer conveyance belt according to the present invention is shown in FIG.
As shown in FIG.
2 is an endless belt having a two-layered structure in which two belts are laminated. Such a transfer conveyance belt is used in such a mechanism as shown in FIGS. 1 and 2 such that the wear-resistant layer 12 is on the side (surface) on which the transfer material (paper) is placed.

The constituent material of the belt main body 11 is not particularly limited as long as it is a material that can secure the tension as the transport belt.
Various types of rubbers and synthetic resins can be used, but they have elasticity and cushioning properties in terms of assembling to a copying machine, securing tension, and reducing shock when rubbing with the cleaning means. Vulcanized rubber is preferably used.

The rubber used for the belt body 1 includes:
Natural rubber (NR), isoprene rubber (IR), acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), polynorbornene rubber, ethylene-propylene-diene copolymer rubber (EPDM), chloroprene rubber (CR), Fluoro rubber (FKM), silicone rubber, epichlorohydrin rubber (ECO), polysulfide rubber, urethane rubber (UR), acrylonitrile-butadiene rubber hydride (HNBR), styrene-butadiene copolymer rubber hydride (HSBR) Butyl rubber (IIR), and the like, and mixtures thereof. Since the transfer conveyance belt is often used under high voltage, it is preferable to use a material containing chloroprene rubber having flame retardancy among the above rubbers.

The resin used for the rubber body 11 includes:
Polyethylene, polypropylene, polystyrene, fluorocarbon resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl acetal, methyl methacrylate, polyacrylate,
Polyamide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, ABS resin, polyacetal, polyether, modified polyphenylene ether, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyamideimide, polyetherimide, polyetheretherketone, polyimide, Thermoplastic resins such as polyaminobismaleimide; and thermosetting resins such as phenolic resins, urea resins, melamine resins, unsaturated polyester resins, epoxy resins, polyurethane resins, diallyl phthalate resins, alone or in combination of two or more. You may mix and use.

When used in a transfer belt system in which the transfer / transport belt itself is charged, the back surface of the transfer / transport belt (the side on which the transfer material is not placed) must have conductivity. That is, it is necessary to make the belt main body 11 corresponding to the back surface of the belt conductive, and it is preferable to add a conductivity imparting agent to the rubber or resin. Examples of the conductivity-imparting agent include carbon black, metal oxide, metal powder, and graphite. Of these, carbon black is preferably used. Examples of the type of carbon black serving as the conductivity imparting agent include channel black, furnace black, acetylene black, and the like.
Those having a particle size of 18 to 120 nm, preferably 22 to 90 nm are suitable. The filling amount of the conductivity-imparting agent may be appropriately selected depending on the required conductivity and the constituent material of the rubber body.

In addition to the conductivity-imparting agent, the belt body 11
If necessary, a filler such as a plasticizer, a filler, a reinforcing agent, a flame retardant, an antioxidant, and a crosslinking agent may be contained. In particular, when the belt body 11 is made of rubber, it is preferable that a vulcanization accelerator, a vulcanization acceleration auxiliary, an anti-scorch agent and the like are blended.

The surface roughness (Rz) of the surface of the belt body 11 (the surface on which the wear-resistant layer 12 is laminated) is 1.8 to 1
It is 5.0 μm. The moderate unevenness of the belt body surface exerts an anchor effect to enhance the adhesion of the wear-resistant layer 12, and the cleaning means such as a blade makes the wear-resistant layer 12
This is because the effect that the convexity on the surface of the belt main body 11 can absorb the stress caused by the rubbing is also expected. In other words, the belt main body 11 is made of a material having a certain degree of elasticity, and the surface of the belt is made to have cushioning properties, so that the contact of the blade with the wear-resistant layer 12 is soft, and It is considered that the attached toner can be scraped off while suppressing abrasion.

In order to keep the surface roughness (Rz) of the belt body 11 within the above range, one side surface may be polished with a grinder, a grindstone, sand or the like after molding. In such a polishing method, the surface roughness can be adjusted by the type of the abrasive, the polishing speed, and the like.

The abrasion resistant layer 12 is a layer made of a material having excellent abrasion resistance from the viewpoint of preventing damage to the cleaning means. It is preferable to use a material having excellent sliding properties such as bleed or the like having excellent sliding characteristics with a cleaning means. Further, it is preferable that the belt body 11 has a followability to the elongation of the belt body 11. The material is not particularly limited as long as it satisfies such requirements, and can be appropriately selected from resins used for the belt body 11, but is soft, rich in elasticity, and excellent in abrasion resistance. Urethane resins, particularly environmentally friendly water-based urethane resins, are preferably used. Here, the aqueous urethane resin refers to a urethane resin containing a hydrophilic group or a urethane resin made water dispersible using a dispersant. The urethane-based resin is a polymer having a urethane bond formed by reacting and curing a polyol and an isocyanate compound. When used in a state of being dispersed in water, it may not have a hydrophilic group. The urethane-based resin is three-dimensionally cured by using a polyol having three or more OH groups or a polyisocyanate compound having three or more isocyanate groups, or by moisture. May be used. Furthermore, the wear-resistant layer 1
In order to improve the slipperiness of No. 2, it is preferable to use a mixture with a fluorinated resin such as polytetrafluoroethylene. Since the surface roughness of the wear-resistant layer 12 is relatively small and smooth as described later, if the slipperiness is poor, the contact resistance with the blade increases, and in severe cases, the roughness of the wear-resistant layer 12 is increased. This is because the abrasion-resistant layer will be worn away in such a state that the temperature rises. The wear-resistant layer 12
When used in a belt transfer system in which the transfer / conveyor belt itself is charged, it also serves as an insulating layer for storing charges on the belt surface.

The surface roughness (Rz) of the wear-resistant layer 12 is as follows.
8 to 9.3 μm. Within this range, the roughness of the wear-resistant layer is preferably smaller than the roughness of the belt body.
In general, since the particle size of the toner particles is 5 to 10 μm, if the surface roughness of the wear-resistant layer 12 is too large, the toner particles enter the concave portions of the wear-resistant layer 12, and the toner particles that have entered This is because bleed, which is a cleaning means, cannot be removed. On the other hand, if the surface roughness is less than 1.8 μm, the surface becomes close to a mirror surface, and the contact area with the cleaning means becomes too large when viewed microscopically, which eventually increases the friction coefficient. Further, the surface roughness (Rz (body)) of the surface of the belt body 11 on which the wear-resistant layer 12 is laminated is equal to or greater than the surface roughness (Rz (wear-resistant layer)) of the wear-resistant layer 12. (R
It is preferable that z (abrasion resistant layer) ≦ Rz (body)). By satisfying such a relationship, a more effective cushioning effect of the belt body can be expected.

The thickness of the wear-resistant layer 12 is 1.0 μm or more,
Preferably it is 2.0 μm or more, 15.0 μm or less, preferably 10.0 μm or less, more preferably 6.0 μm or less. When the thickness is less than 1.0 μm, the surface roughness of the belt body 11 is easily affected. In particular, when the surface roughness of the belt body 11 is large, it is difficult to set the surface roughness of the wear-resistant layer 12 within the above range. This is because, in severe cases, the convex portions of the belt main body 11 are exposed. On the other hand, if it exceeds 15.0 μm, the wear-resistant layer 12 which is generally harder than the belt
This is because a crack cannot be produced due to the elongation of the belt 1 and the cushion effect due to the unevenness of the surface of the belt main body 11 is lost, and the contact with the blade tends to cause the abrasion of the wear-resistant layer 12. Therefore, it is preferable that the thickness of the wear-resistant layer 12 be appropriately selected within the above range according to the surface roughness of the belt main body 11. Generally, when it is desired to reduce the surface roughness of the wear-resistant layer 12, the thickness of the wear-resistant layer 12 may be increased.

The abrasion-resistant layer 12 is formed by applying a resin composition constituting the abrasion-resistant layer 12 to the surface of the belt body 11 having a predetermined surface roughness, and drying and curing the resin composition. As a coating method, a conventionally known coating method can be applied. However, when the belt body has conductivity, an electrostatic coating method is preferably used.

The surface roughness of the wear-resistant layer 12 is determined by adjusting the viscosity of the resin composition for forming the wear-resistant layer, the filler (for example, a leveling agent) of the resin composition, the coating method, the thickness of the wear-resistant layer, and the like. By appropriately setting, the wear-resistant layer 12 having a surface roughness within the above range can be formed. First, similarly to the case of the belt main body 11, after the formation of the wear-resistant layer 12, the surface roughness may be adjusted to be within the above range by polishing or the like.

[0028]

EXAMPLES [Preparation of transfer belt] A rubber composition prepared by mixing and kneading at the ratios shown in Table 1 was extruded into a belt shape by an extruder to obtain an unvulcanized rubber belt, which was then vulcanized. After the vulcanization, a foaming whetstone (Clenoton) is attached to a cylindrical grinder (manufactured by Mizuguchi Seisakusho), the polishing speed is changed, and the belt body having a surface roughness (Rz) of 2.2 to 14.7 μm. I got The size of the belt body is 51m inside diameter
m, width 340 mm, thickness 0.5 mm. The rubber used for the belt body is a rubber having a JIS A hardness of 65 in a sample having a thickness of 12 mm.

Next, the coating composition prepared by mixing at a ratio shown in Table 1 and uniformly stirring with a ball mill was coated on one surface of the belt main body with an average thickness of 5 μm on one side surface of the belt body using an electrostatic coating machine.
m. However, for Comparative Example 1, the average thickness was about 18 μm. As described above, Examples 1 to 3 in which the roughness of the belt body and the wear-resistant layer are different
4. Transfer transfer belts of Comparative Examples 1 to 3 were produced.

[0030]

[Table 1] [Evaluation] Each of the transfer / transport belts obtained as described above employs a belt transfer system as shown in FIG.
After being mounted on a Ricoh copying machine “SPIRIO-3550” and copying 30,000 sheets, the surface condition of the transfer belt was visually observed. In any case, no crack was recognized in the wear-resistant layer and the belt body. Further, durability and toner releasability were evaluated based on the surface condition of the transfer / conveying belt. Regarding the durability, the case where no change was observed on the surface of the transfer belt was evaluated as “○”, and the case where changes such as peeling of the abrasion-resistant layer and scraping were observed was evaluated as “X”. Regarding the toner releasability, whether or not the toner remained on the surface of the transfer / conveying belt was observed. The case where no toner remained was evaluated as “○”, and the case where the toner remained was evaluated as “×”. Table 2 shows the evaluation results together with the surface roughness of the belt body and the wear-resistant layer of Examples 1 to 4 and Comparative Examples 1 to 3.
Shown in

The surface roughness was measured using a surface roughness profile measuring machine Surfcom 570A manufactured by Tokyo Seimitsu Co., Ltd.
Measurement speed 0.3mm / sec, cutoff 0.8mm,
Needle tip 5μm, load 0.07g, measurement length 2.5mm
It measured on condition of.

[0032]

[Table 2] In the transfer conveyance belt in which both the surface roughness of the belt main body and the abrasion resistant layer were within the range of the present invention, no abrasion of the abrasion resistant layer was observed, and no residual toner was observed.

On the other hand, in Comparative Example 3, the toner adhered to the entire belt surface after the test. It is probable that the roughness of the wear-resistant layer was so rough that the toner entered the recess and could not be scraped off by the blade. On the other hand, in Comparative Example 1, although the wear-resistant layer was thicker than the others, the wear-resistant layer was worn away,
Exposure of the belt body was observed. Because the surface roughness of the wear-resistant layer was too small, the protrusions on the surface of the wear-resistant layer were quickly worn away,
This is probably due to the fact that the surface became more mirror-like and the wear further advanced. In Comparative Example 2, although the surface roughness of the wear-resistant layer was within the range of the present invention, the wear-resistant layer was worn away and the belt body was exposed. This is presumably because the roughness of the belt main body is small, and the effect of absorbing the stress when the blade slides due to the unevenness of the surface of the belt main body is small.

[0034]

According to the transfer conveyance belt of the present invention, the toner is hardly adhered by setting the surface roughness of the belt body and the wear-resistant layer in a predetermined range, and the adhered toner is easily peeled off by the cleaning means. Less wear due to cleaning means and excellent durability. Also, 2
Since it has a layer structure and the surface roughness is only within a predetermined range, it can be manufactured at a lower cost than before.

Therefore, by using the transfer conveyance belt of the present invention, it is possible to realize a transfer area with less back stain on the transfer material and excellent durability without increasing the cost.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an outline of a transfer mechanism using a transfer conveyance belt.

FIG. 2 is a diagram illustrating an outline of a transfer mechanism using a transfer conveyance belt.

FIG. 3 is a diagram illustrating a configuration of a transfer conveyance belt of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1 'Transfer conveyance belt 4 Transfer material 10 Cleaning means 11 Belt main body 12 Abrasion resistant layer

Claims (4)

[Claims] 1. A transfer conveyance belt used for a mechanism having a cleaning means for conveying a transfer material to a transfer area and removing adhered toner by rubbing, and a side of the belt body on which the transfer material is mounted. A transfer conveyance belt having a two-layer structure in which a wear-resistant layer is laminated on the surface, wherein the wear-resistant layer has a thickness of 1.0 to 15.0 μm, and a surface of the belt body on which the wear-resistant layer is laminated. Wherein the surface roughness of the abrasion-resistant layer is 1.8 to 9.3 μm. 2. The surface roughness (Rz (body)) of the surface of the belt body on which the wear-resistant layer is laminated is equal to the surface roughness (Rz (wear-resistant layer)) of the resin wear-resistant layer. (R
2. The transfer conveyance belt according to claim 1, wherein z (abrasion resistant layer) ≦ Rz (body)). 3. The transfer conveyance belt according to claim 1, wherein the belt main body is made of vulcanized rubber. 4. The transfer conveyance belt according to claim 1, wherein the wear-resistant layer is made of an aqueous urethane resin containing a fluorine-containing resin.