JPH10207242A - Transfer belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer belt which is constituted so that a copying paper is excellently carried, a toner image is excellently transferred and the copying paper is excellently separated and whose electric property is excellent. SOLUTION: This transfer belt 11 is provided with a surface layer 9 and a supporting layer 10 supporting the layer 9. Then, the layer 9 is formed of a material including a component A described hereunder and the layer 10 is formed of a material including a component B, a component C and a component D described hereunder. A is at least one of electrical conductive fluoro rubber and electrical conductive fluororesin. B is at least one of ethylene-propylene rubber and ethylene-propylene dien rubber. C is at least one synthetic rubber selected from a group consisting of acrylonitrile-butadiene rubber, hydroacrylonitrile-butadiene rubber and ethylene-acrylic rubber. D is peroxide curing agent.

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 section of an electrophotographic copying machine, a printer, a facsimile, or the like, for transferring a toner image on an image carrier to a sheet or conveying the sheet. is there.

[0002]

2. Description of the Related Art Generally, copying by an electrophotographic copying machine is
A document image is formed on a rotating photosensitive drum as an electrostatic latent image,
A toner image is formed by attaching toner to the toner, and the toner image is transferred to copy paper. In the step of transferring the toner image onto the copy paper, the toner image 2 on the surface of the photosensitive drum 1 is transferred to the copy paper 4 sandwiched between the photosensitive drum 1 and the transfer belt 3, as shown in FIG. It is designed to be transcribed. Reference numeral 5 denotes a driving roller for driving the transfer belt 3, and reference numeral 6 denotes a driven roller that can move with the driving. Reference numeral 7 denotes a cleaning blade that removes residual toner on the transfer belt 3, and reference numeral 8 denotes an electrode roller that charges the transfer belt 3 to transfer the toner image 2 on the surface of the photosensitive drum 1 to the copy paper 4.

In general, the transfer belt 3 used in such a transfer process has good functions such as conveying the copy paper 4, transferring the toner image 2 to the copy paper 4, and separating the transferred copy paper. Is required. And from the past,
A transfer belt made of at least one of ethylene-propylene rubber (hereinafter abbreviated as “EPM”) and ethylene-propylene-diene rubber (hereinafter abbreviated as “EPDM”) is used to substantially satisfy these functions.

[0004]

However, the above E
Since both PM and EPDM are electrically insulating substances, a transfer belt (hereinafter referred to as an “EPDM transfer belt”) produced using these materials generates a strong electrostatic force between the transfer belt and the copy paper 4. I do. For this reason, although the transfer belt made of EPDM is good for conveying the copy paper 4,
Conversely, when the transferred copy paper and the EPDM transfer belt are separated by the electrostatic force, a peeling discharge occurs, which causes a problem that the toner image (copy image) of the transferred copy paper is disturbed. Further, in the above-mentioned EPM and EPDM, there is a problem that the transfer of the toner image 2 from the photosensitive drum 1 to the copy paper is not performed uniformly because the electrical resistance greatly fluctuates with environmental changes.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transfer belt which improves the conveyance of a copy sheet, the transfer of a toner image and the separation of a copy sheet, and has excellent electrical characteristics. And

[0006]

In order to achieve the above object, a transfer belt according to the present invention comprises a surface layer and a support layer for supporting the same, wherein the surface layer contains the following component (A). And the support layer is formed of a material containing the following components (B), (C) and (D). (A) at least one of a conductive fluororubber and a conductive fluororesin. (B) at least one of ethylene-propylene rubber and ethylene-propylene-diene rubber. (C) at least one synthetic rubber selected from the group consisting of acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, and ethylene-acrylic rubber. (D) a peroxide vulcanizing agent.

That is, the inventors of the present invention convey copy paper,
A series of studies were conducted to obtain a transfer belt with good transfer of the toner image and good separation of the copy paper. In the process, in order to improve the copy image while maintaining the excellent copy paper conveyance force of the EPM and EPDM, it is necessary to use the EPM and EDM.
He recalled that a layer capable of forming a good toner image and transferring the toner image satisfactorily could be provided on the surface of the transfer belt made of PDM. As a result, it has been found that the intended purpose can be achieved by providing the surface layer containing the component (A) and the support layer containing the components (B), (C) and (D). Reached the present invention.

[0008]

Next, an embodiment of the present invention will be described.

The transfer belt of the present invention comprises a surface layer containing the fluorine-based material (component (A)), the EPDM-based material (component (B)), and the synthetic rubber (component (C)).
And a support layer containing the peroxide vulcanizing agent (component (D)).

An example is shown in FIG. This transfer belt 1
1 has a two-layer structure, the surface layer 9 is formed of a material containing the fluorine-based material [component (A)], and the support layer 10 laminated thereon is formed of the EPDM-based material [component (B). ]
And the synthetic rubber [(C) component] and the peroxide vulcanizing agent [(D) component].

As the fluorine-based material (component (A)) used as the material for forming the surface layer 9, a conductive fluorine-containing rubber or a conductive fluorine-containing resin is used. These may be used alone or in combination. Among them, a conductive fluororesin paint is preferred from the viewpoint of workability.
The “conductive” in the conductive fluororubber and the conductive fluororesin refers to a volume resistivity of 10 ⁷ to 10 ^12.
It means about Ω · cm.

As the conductive fluorine rubber, for example, a rubber obtained by blending ethylene-acryl rubber, carbon black and a peroxide vulcanizing agent with a fluorine rubber is used. The conductive fluorine-based rubber is used in a liquid form by dissolving it in a solvent such as ethyl acetate so as to facilitate spray coating.

As the conductive fluororesin, Eight Seal F20V (manufactured by Taihei Kasei Co., Ltd.), Lumiflon F600C
Commercially available conductive fluororesin paints such as (made by Asahi Glass Co., Ltd.) and LC950 (made by Daikin Industries, Ltd.) are used. These commercially available products are made conductive by adding a conductive filler such as carbon black to a fluorine-based material. The conductive fluororesin is also dissolved in a solvent or the like and used in a liquid state so as to be easily spray-coated.

EPDM materials (component (B)) used as a material for forming the support layer 10 include EPM and EPM.
PDM is used. These may be used alone or in combination.

The above-mentioned EPM is JSREP961S
A commercially available product such as P (manufactured by Nippon Synthetic Rubber Co., Ltd.) is used. When the EPM is used, the transfer belt 11 can be provided with characteristics such as weather resistance, heat aging resistance, and ozone resistance of the EPM itself.

The above EPDM is JSREP.
Commercial products such as E.51 (manufactured by Nippon Synthetic Rubber Co., Ltd.) and Esplen E514 (manufactured by Sumitomo Chemical Co., Ltd.) are used.
When not only is used, the same effect as the EPM is obtained, but also the effect of improving the mixing property with other synthetic rubbers is obtained.

The synthetic rubber [component (C)] used together with the above EPDM-based material [component (B)] includes acrylonitrile-butadiene rubber (hereinafter abbreviated as “NBR”) and hydrogenated acrylonitrile-butadiene rubber (hereinafter “H”). -NBR ") and ethylene-acrylic rubber (hereinafter abbreviated as" EMA "). These synthetic rubbers (component (C)) may be used alone or in combination of two or more. In addition, the above synthetic rubber [(C) component]
Of the EPDM-based material [component (B)] and 100 parts by weight of the synthetic rubber [component (C)].
It is preferable that the amount is set within the range of 30 to 30 parts by weight. That is, if it is less than 10 parts by weight, the effect of reducing the electric resistance and improving the electric resistance environmental stability obtained by co-vulcanization with the EPDM-based material [component (B)] may not be obtained. If the amount exceeds 30 parts by weight, characteristics derived from the EPDM-based material [component (B)], that is, excellent copy paper conveying force may not be obtained.

As the NBR, for example, JSRN2
Commercial products such as 41 (manufactured by Nippon Synthetic Rubber Co., Ltd.) are used. When these NBRs are used, characteristics such as wear resistance, high tensile strength and hardness of the NBR itself can be imparted to the transfer belt 11.

As the H-NBR, for example, commercially available products such as Zetpol 2030L, Zetpol 2020L, Zetpol 2010L, Zetpol 2000L (manufactured by Nippon Zeon Co., Ltd.) are used. When these H-NBRs are used, characteristics such as high durability and chemical stability of the H-NBR itself can be imparted to the transfer belt 11.

As the EMA, for example, commercially available products such as Esplen EMA2752 and Esplen EMA2152 (manufactured by Sumitomo Chemical Co., Ltd.) are used. When these EMAs are used, the EMA itself has characteristics such as weather resistance and chemical stability. It can be applied to the transfer belt 11. EMA is also very inexpensive and economically superior.

Further, the peroxide vulcanizing agent [component (D)] used together with the EPDM material [component (B)] and the synthetic rubber [component (C)] includes dicumyl peroxide, 1,3- Bis (t-butylperoxyisopropyl) benzene, 1,4-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 2,5-
Dimethyl-2,5-di-t (butylperoxy) hexine, n-butyl-4,4-bis (t-butylperoxy) valerate and the like. These may be used alone or in combination of two or more. The mixing ratio of the peroxide vulcanizing agent [(D) component] is 100% for the EPDM-based material [(B) component] and the synthetic rubber [(C) component].
It is preferable that the amount is set in the range of 1 to 10 parts by weight with respect to parts by weight. More preferably, it is 2 to 5 parts by weight. That is, if it is less than 1 part by weight, sufficient vulcanization may not be performed, and if it exceeds 10 parts by weight,
An unreacted peroxide vulcanizing agent remains in the obtained transfer belt 11, and when the transfer belt 11 is used in an electrophotographic copying machine, the obtained copied image may be defective. Because.

The material for forming the support layer 10 is as follows.
EPDM-based material [component (B)], synthetic rubber [(C)
Component), a peroxide vulcanizing agent [component (D)], and other additives such as a conductive filler such as carbon black, a filler, a softener, a crosslinking assistant, an antioxidant, and a processing assistant. It is appropriately blended.

The transfer belt 11 of the present invention uses the material for forming the surface layer 9 and the material for forming the support layer 10.
It is produced as follows. That is, first, the support layer 1
The 0-forming material is mixed with a closed mixer, an open roll or the like. Then, the mixture is put into a mold and heated in a nitrogen atmosphere to be peroxide-vulcanized to produce a molded body that becomes the support layer 10. On the other hand, the material for forming the surface layer 9 is mixed with a solvent, if necessary, so as to be in a liquid state.
The transfer belt 11 shown in FIG. 1 can be obtained by spray-coating on the surface of the molded article which becomes zero and co-vulcanizing (or baking) with the support layer 10 by heating in a nitrogen atmosphere. The transfer belt 11 includes the surface layer 9 having a relatively small thickness.

The transfer belt 11 thus obtained
Is to carry out peroxide vulcanization of synthetic rubber [(C) component] to suppress electrical insulation by EPDM-based material [(B) component] and to improve electrical characteristics such as reduction of electrical resistance. ing. In addition, excellent copy paper conveying force derived from the EPDM material [component (B)] is maintained. The support layer 10 containing the EPDM-based material [component (B)] and the like
Since the surface layer 9 containing the fluorine-based material [component (A)] is formed on the surface of the transfer belt 11, the transfer belt 11 has excellent toner releasability. When the surface layer 9 was formed, the surface layer 9 and the support layer 1 were formed by the action of the peroxide vulcanizing agent [component (D)] contained in the support layer 10.
0 is co-vulcanized and adheres strongly, so that there is no need to provide an adhesive layer between the surface layer 9 and the support layer 10. In addition, such co-vulcanization provides not only the support layer 10 but also the transfer belt 11 as a whole with excellent electrical characteristics.

The thickness of the support layer 10 is 0.4 to 0.4.
Preferably, it is set within the range of 0.6 mm.
That is, if the transfer belt 1 is not within the above range, the resulting transfer belt 1
This is because there is a possibility that excellent effects derived from the support layer 10 such as excellent copy paper conveying force cannot be provided.

The thickness of the surface layer 9 is 5 to 30 μm.
m is preferably set within the range of m. More preferably, it is 15 to 25 μm. That is, within the above range, the effect derived from the surface layer 9, that is, the effect such as the toner releasability, is favorably imparted to the transfer belt 11.

Further, as a characteristic of the entire transfer belt 11, it is preferable that its volume resistivity is set within a range of 10 ⁷ to 10 ¹¹ Ω · cm. More preferably 1
0 ⁸ to 10 ¹⁰ Ω · cm. That is, 10 ⁷ Ω · c
If it is less than m, the charge may decay too quickly and the capacity of the power supply may need to be increased. If it exceeds 10 ¹¹ Ω · cm, the charge may decay too slowly and a system for static elimination may be required. Because.

It is preferable that the variation of the surface electric resistance of the transfer belt 11 due to the environmental change is suppressed to about one digit. That is, if the surface electric resistance greatly varies due to a change in the environment, when the obtained transfer belt 11 is incorporated in an electrophotographic copying machine or the like, the copied image may be disturbed.

The transfer belt of the present invention can also be manufactured using the material for forming the surface layer 9 and the material for forming the support layer 10 as follows, for example. That is, first, a material for forming the surface layer 9 is prepared, and a molded body to be the surface layer 9 is prepared using an extruder or the like, and the support layer 10
A molded body to be the support layer 10 is manufactured using an extruder or the like using the same forming material. Then, by sticking them together and performing peroxide vulcanization, the transfer belt 11 shown in FIG.
Is obtained. In this case, also in this case, the surface layer 9 and the support layer 10
At the bonding interface of the above, co-vulcanization occurs due to the action of the peroxide vulcanizing agent [component (D)] in the material for forming the support layer 10 and the surface layer 9
The support layer 10 can be bonded without using an adhesive. The transfer belt 11 has a two-layer structure in which a surface layer 9 and a support layer 10 are laminated, similarly to the transfer belt obtained by the above-described manufacturing method. It becomes the belt 11.

Transfer belt 11 obtained by the above method
The thickness of the support layer 10 is preferably set in the range of 0.4 to 0.6 mm, similarly to the case where the support layer 10 is manufactured by the above-described manufacturing method.

The thickness of the surface layer 9 of the transfer belt 11 obtained by the above-described manufacturing method is preferably set in the range of 50 to 150 μm, unlike the case of manufacturing by the above-described manufacturing method. More preferably, 80
１２０120 μm. That is, if not within the above range,
This is because, in the case of this production method, there is a possibility that the surface layer 9 may be cracked during the production of the transfer belt 11. It goes without saying that even if the thickness of the surface layer 9 of the transfer belt 11 obtained by this manufacturing method becomes large, there is no problem in the operation of the transfer belt 11.

The transfer belt of the present invention is not limited to a transfer belt of an electrophotographic copying machine, but can be used as a transfer belt of a printer, a facsimile or the like.

Next, examples will be described together with comparative examples.

[0034]

Examples 1 to 10 First, materials for forming a support layer were blended at the blending ratios shown in Tables 1 and 2 below, and mixed with a closed mixer, an open roll, or the like. Then, the mixture is put into a mold and peroxide vulcanized (vulcanization conditions: 170 ° C. × 30 minutes).
In this way, a molded article to be a support layer was produced. Next, a liquid surface layer forming material is spray-coated on the molded article to be the support layer, and heated (140 to 160 ° C. × 30 to 60 ° C.).
), The surface layer was baked on the support layer to produce a target transfer belt.

[0035]

Example 11 In the same manner as in Example 1 except for the compounding ratio shown in Table 3 below, a molded article to be a support layer was produced. Then, the surface layer forming material dissolved in a solvent (ethyl acetate, 18 parts by weight) is spray-coated on the molded article to be the support layer, and co-vulcanized by heating (170 ° C. × 30 minutes) in a nitrogen atmosphere. Thus, an intended transfer belt was produced.

[0036]

Example 12 Similarly, a material for forming a support layer was compounded at the compounding ratio shown in Table 3 below, and a molded product to be a support layer was prepared using an extruder. A molded body to be a surface layer was produced using the material. Then, the molded body to be the surface layer and the molded body to be the support layer were bonded together and co-vulcanized by heating (160 ° C. × 60 minutes) to produce a target transfer belt.

With respect to the transfer belt thus manufactured, the thickness of the surface layer and the support layer, the surface electric resistance, the volume resistivity, and the toner releasability were examined. The results are shown in Tables 4 and 5 below. In addition, each measuring method is as follows.

[Thickness] The thickness was measured using a micrometer.

[Surface Electric Resistance and Volume Resistivity] JIS
The measurement was performed at an applied voltage of 500 V according to K6911.

[Toner Releasability] As shown in FIG. 4, a paper (Coffe 17 manufactured by KOKUYO Co., Ltd.) 20 coated with toner on the surface is used.
The transfer belt 21 was placed on the surface, and a weight W (400 g) was placed on the transfer belt 21. In this state, the transfer belt 21 is moved 500 mm / mi in the direction of arrow A.
Pulled with n. Next, the surface of the transfer belt 21 was wiped with white paper (Kimwipe), and the stain was visually observed.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

[0044]

[Table 4]

[0045]

[Table 5]

[0046]

Comparative Examples 1 and 2 Transfer belts were prepared in the same manner as in Example 1 except for the mixing ratios shown in Table 6 below. This transfer belt was evaluated in the same manner as in Example 1, and the results are shown in Table 7 below.

[0047]

Comparative Examples 3 and 4 Transfer belts were produced in the same manner as in Example 1 except that the surface layers were not formed at the compounding ratios shown in Table 6 below. This transfer belt was evaluated in the same manner as in Example 1, and the results are shown in Table 7 below.

[0048]

[Table 6]

[0049]

[Table 7]

The products of Examples 1 to 12 are all excellent in toner peelability. Further, the surface electric resistance does not fluctuate greatly with changes in the environment, and the fluctuation is suppressed to about one digit. The volume resistivity is also kept low. On the other hand, the products of Comparative Examples 1 and 2 are excellent in toner releasability, but have a large volume resistivity, so that the strength between the transfer belt and the copy paper is high. A strong electrostatic force is generated, and the copied image is disturbed. Further, Comparative Examples 3 and 4 do not have a surface layer containing a fluorine-based material (component (A)), and thus have poor toner releasability. And the volume resistivity is also large,
Therefore, as described above, the copied image is disturbed.

[0051]

As described above, the transfer belt of the present invention has a surface layer containing a fluorine-based material (component (A)), an EPDM-based material (component (B)) and a synthetic rubber [(C ) Component) and a support layer containing a peroxide vulcanizing agent [component (D) component]. For this reason, the transfer belt of the present invention has excellent electrical properties without impairing the excellent copying paper conveying force of the EPDM-based material (component (B)). In addition, since the fluorine-based material (component (A)) is used as the surface layer, the transfer belt has excellent toner releasability. The peroxide vulcanizing agent [component (D)] contained in the support layer shares the EPDM material [component (B)] and the synthetic rubber [(C) component] contained in the same support layer. In addition to vulcanizing (peroxide vulcanizing) to reduce the electrical resistance, it also co-vulcanizes with the fluorine-based material (component (A)) contained in the surface layer to strengthen the support layer and the surface layer. Therefore, there is an advantage that it is not necessary to separately provide an adhesive layer for bonding the two layers.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a transfer belt of the present invention.

FIG. 2 is a sectional view showing another example of the transfer belt of the present invention.

FIG. 3 is a configuration diagram illustrating a transfer process of the electrophotographic copying machine.

FIG. 4 is an explanatory view showing a method for measuring and evaluating toner releasability.

[Explanation of symbols]

 9 surface layer 10 support layer 11 transfer belt

Claims (1)

[Claims] A surface layer and a supporting layer for supporting the surface layer, wherein the surface layer is formed of a material containing the following component (A), and the supporting layer is formed of the following component (B), A) a transfer belt formed of a material containing component (A) and component (D); (A) at least one of a conductive fluororubber and a conductive fluororesin. (B) at least one of ethylene-propylene rubber and ethylene-propylene-diene rubber. (C) at least one synthetic rubber selected from the group consisting of acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, and ethylene-acrylic rubber. (D) a peroxide vulcanizing agent.