JPH0990736A - Manufacture of roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll manufacturing method which enables the manufacture of a roll prevented from producing toner filming. SOLUTION: In a roll manufacturing method of forming the fluororubber- made outermost layer 13 by vulcanizing this after an outer peripheral surface of a roll base body 10 is coated with a coating liquid of a fluororubber composition, the roller manufacturing method uses the following (A) material as a coating liquid of a fluororubber composition. (A) A coating liquid of a fluororubber composition is prepared by stopping agitation when viscosity becomes constant by raising the viscosity by agitating it at a heating temperature after at least one of reactive silicone oil and reactive fluorine oil is blended in fluororubber dissolved in a solvent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a roll such as a developing roll which comes into contact with a toner, and more specifically, it has an outermost layer excellent in toner releasability. The present invention relates to a roll manufacturing method capable of manufacturing a roll.

[0002]

2. Description of the Related Art In an electrophotographic copying machine or the like, for a roll which comes into contact with toner, such as a developing roll, it is required to prevent the toner from adhering to the roll surface as an important characteristic. Therefore, the outermost layer of such a roll is formed by using a fluororubber composition having excellent mold releasability, and in order to further improve the releasability, the fluororubber composition has a release agent. Contains silicone oil.

[0003]

However, since the fluororubber and the silicone oil have poor compatibility, the silicone oil may be present in the fluororubber matrix in the form of large aggregates. In such a state, for example, in the developing roll of an electrophotographic copying machine, the supply of silicone oil to the roll surface becomes uneven,
As a result, toner adheres to the portion where the silicone oil is deficient, and this causes the toner to spread further, and eventually toner filming occurs.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a roll manufacturing method capable of manufacturing a roll having an outermost layer excellent in toner releasability.

[0005]

In order to achieve the above object, the method of manufacturing a roll according to the present invention is such that a coating liquid of a fluororubber composition is applied to the outer peripheral surface of a roll substrate and then vulcanized to fluorinate the coating liquid. A method of manufacturing a roll for forming an outermost rubber layer, wherein a coating liquid of the above-mentioned fluororubber uses the following (A). (A) Fluorine rubber dissolved in a solvent is mixed with at least one of reactive silicone oil and reactive fluorine oil and stirred under heating to increase the viscosity, and when the viscosity becomes constant, the stirring is stopped. A coating liquid of the fluororubber composition prepared by.

[0006] The roll base is one in which the outermost layer is not formed. For example, in the case of only the shaft body or on the outer periphery of the shaft body,
It refers to those in which an elastic layer serving as an innermost layer or an intermediate layer is formed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the process for producing a roll of the present invention is characterized by using a coating solution of a special fluororubber composition for forming the outermost layer. The coating liquid of this special fluororubber composition will be described. This contains a fluororubber and at least one of the above-mentioned reactive silicone oil and reactive fluorooil. Then, when the above-mentioned fluororubber is dissolved in a solvent and the above-mentioned reactive silicone oil or the like is added thereto and stirred under a heating condition, the viscosity is increased. Then, when the increase in the viscosity becomes slow and becomes a constant value, the stirring is stopped to prepare a coating solution of the fluororubber composition. In the fluororubber composition coating liquid thus obtained, the particles of the above-mentioned reactive silicone oil and the like become fine particles having a particle size of about 50 μm or less, and react with fluororubber molecules to cause reaction fixation between fluororubber molecules. To be done. This reaction fixing is based on a chemical bonding reaction between a reactive group such as a reactive silicone oil and a fluororubber molecule. In this state, the fluororubber itself is unvulcanized and not crosslinked. Then, a vulcanizing agent dissolved in a solvent is added to the coating liquid of the fluororubber composition, the vulcanizing agent is applied to the outer peripheral surface of the roll substrate, dried if necessary, and then heat vulcanized to form the outermost layer. To form.
In the outermost layer of the roll thus obtained, fine particles of a reactive silicone oil or the like, which is a toner releasing agent, are uniformly dispersed in the fluororubber matrix and are fixed by reaction. This state is shown in the schematic diagram of FIG. 1. In the fluororubber matrix 1, particles 2 formed of a reactive silicone oil or the like react with the fluororubber molecule 1a and are chemically bonded. This chemical bond differs depending on the type of reactive group such as reactive silicone oil. In this reaction fixation, it is not necessary to chemically bond all the reactive silicone oils and the like, and the particles are reactively fixed mainly by chemically bonding the reactive silicone oils and the like located on the surface of the particles. Then, as described above, the particle size of the particles 2 is
It is about 50 μm or less, and is uniformly dispersed. In such a case, for example, in the developing roll having the outermost layer formed by using this rubber composition, the reactive silicone oil or the like, which is a release agent, does not exude into a large aggregate. As a result, this developing roll maintains high toner releasability for a long period of time, and toner filming is prevented from occurring.

Next, the present invention will be described in detail.

The rubber composition used in the roll manufacturing method of the present invention comprises fluororubber and reactive silicone oil (a component).
And at least one of reactive fluorine oil (component b).

The above-mentioned fluororubber is not particularly limited, and conventionally known ones may be used, but tetrafluoroethylene-polypropylene (TFE-) is used because of its low polymer viscosity and good dispersibility of the filler. It is preferable to use a PP) copolymer and the following general formula (1)
It is particularly preferable to use a random copolymer having the structure shown in.

[0011]

Embedded image

In the above formula (1), the ratio of each repeating portion m, n, p is a weight ratio of m: n: p = (30 to
60) :( 10-40): It is preferable to use those set to (10-40), and particularly preferably, m:
n: p = (30 to 50) :( 30 to 40) :( 20 to 3)
0).

Next, the above-mentioned reactive silicone oil (a component) and reactive fluorine oil (b component) compounded in the above-mentioned fluororubber are toner release agents, and both of the above-mentioned a-component and b-component are included. They may be blended, or either one of the above two components may be blended alone.

Both the reactive silicone oil (a component) and the reactive fluorine oil (b component) are at least selected from the group consisting of a hydroxyl group, an amino group, a mercapto group, an epoxy group, a carboxyl group and a methacryl group. It is preferable to have one reactive group. As mentioned above, these reactive groups react with the fluororubber, thereby fixing the particles formed from the oil in the fluororubber matrix. The manner of this reaction fixation is shown below for each of the above reaction groups.

[Hydroxyl group]

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[Amino group]

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[Mercapto group]

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[Epoxy group]

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[Carboxyl group]

[Chemical 6]

[Methacrylic group]

[Chemical 7]

Further, these reactive groups are located at the ends of the molecular chain (including both ends) and side chains, and differ depending on the type of oil and the like.

Of the above-mentioned reactive groups, a hydroxyl group, an amino group and a mercapto group are preferable because of their excellent reactivity, and an amino group is particularly preferable. For thermal stability, the reactive silicone oil (a component) preferably has an average molecular weight of 300 or more, and the reactive fluorine oil (b component) preferably has an average molecular weight of 200 or more,
Particularly preferably, both have an average molecular weight of 1500 to 200.
00. Further, the total blending ratio (a + b) of these reactive silicone oil (a component) and reactive fluorine oil (b component) is 0.5 to 100 relative to 100 parts by weight of the fluororubber (hereinafter abbreviated as "part"). The range of parts is preferable, and the range of 15 to 50 parts is particularly preferable.

Specific examples of such reactive silicone oil (a component) and reactive fluorine oil (b component) are shown below.

[Reactive Silicone Oil Having Hydroxyl Group]

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[Reactive Silicone Oil Having Amino Group]

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[Reactive Silicone Oil Having Mercapto Group]

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[Reactive Silicone Oil Having Epoxy Group]

Embedded image

[Reactive Silicone Oil Having Carboxyl Group]

[Chemical 12]

[Reactive Silicone Oil Having Methacrylic Group]

Embedded image

[Reactive Fluorine Oil Having Hydroxyl Group]

Embedded image

[Reactive Fluorine Oil Having Amino Group]

[Chemical 15]

[Reactive Fluorine Oil Having Mercapto Group]

Embedded image

[Reactive Fluorine Oil Having Epoxy Group]

Embedded image

[Reactive Fluorine Oil Having Carboxyl Group]

Embedded image

[Reactive Fluorine Oil Having Methacrylic Group]

Embedded image

Among the reactive silicone oils (component a) and reactive fluorine oils (component b) shown in the above specific examples, those having a hydroxyl group, an amino group or a mercapto group are preferable because of their good reactivity. It has at least one, and particularly preferably has an amino group.

Next, in the present invention, in addition to the above-mentioned reactive silicone oil (a component) and reactive fluorine oil (b component), a non-reactive silicone oil (c component) and a non-reactive substance are added to the fluororubber composition. Fluorine oil (component d) can be added. This non-reactive silicone oil or non-reactive fluoro oil does not have a reactive group for being reactively fixed in the fluoro rubber matrix, but when used in combination with the above reactive silicone oil, etc. Fixed. This is because the non-reactive silicone oil and the like are mixed in the particles formed from the reactive silicone oil and the like, and both are bonded by a hydrophobic bond,
As a result, it is assumed that non-reactive silicone oil and the like are fixed in the fluororubber matrix. Therefore, even if the non-reactive silicone oil or the non-reactive fluorine oil is used, no adverse effect such as generation of large agglomerates of the non-reactive silicone oil or the non-reactive fluorine oil occurs.

The above non-reactive silicone oil (component c)
Is preferably one having at least one organic group selected from the group consisting of an alkyl group, an aralkyl group, a higher alcohol ester group, and a polyether fluoroalkyl group. This is because the releasability is excellent.

Further, among the above-mentioned non-reactive silicone oils, because of their excellent releasability and thermal stability,
Those having an average molecular weight in the range of 500 to 100,000 are preferable, and particularly preferably, the average molecular weight is in the range of 2000 to 5000.
It is in the range of 0.

The total compounding ratio (c + d) of the non-reactive silicone oil (component c) and the non-reactive fluorine oil (d component) is usually set in the range of 10 to 100 parts per 100 parts of fluororubber. Preferably 2
It is in the range of 0 to 50 parts, particularly preferably in the range of 30 to 40 parts.

Specific examples of such a non-reactive silicone oil are shown below.

[Non-Reactive Silicone Oil Having Alkyl Group]

Embedded image

[Non-Reactive Silicone Oil Having Aralkyl Group]

[Chemical 21]

[Non-Reactive Silicone Oil Having Higher Alcohol Ester Group]

Embedded image

[Non-Reactive Silicone Oil Having Polyether Fluoroalkyl Group]

Embedded image

Among the non-reactive silicone oils shown as these specific examples, those having an alkyl group, a higher alcohol ester group or a polyether fluoroalkyl group are preferably used because of their excellent releasability. Those having a higher alcohol ester group are preferred.

As the non-reactive fluorine oil, perfluoropolyether or the like is used.

The rubber composition of the present invention contains the above-mentioned reactive silicone oil (a component), reactive fluorine oil (b component), non-reactive silicone oil (c component) and non-reactive fluorine oil (d). In addition to the (component), an ionic conductive agent can be added for the purpose of imparting an appropriate volume electric resistance (10 ⁷ to 10 ¹² Ω · cm). The characteristic relating to the volume electric resistance is important as the characteristic of the outermost layer of the developing roll, for example.

Examples of the ionic conductive agent include trimethyloctadecyl ammonium chloride, benzyl trimethyl ammonium chloride, trioctyl propylene ammonium chloride, trioctyl propyl ammonium bromide, trimethyl octadecyl ammonium perchlorate, tetrabutyl ammonium hydrogen sulfate, tetrabutyl ammonium. Quaternary ammonium compounds such as hydroxide and perchlorates and benzoates of these quaternary ammonium compounds,
Examples thereof include nitrite, sulfate, and hydroxide. These may be used alone or in combination of two or more. Above all,
It is preferable to use tetrabutylammonium hydrogen sulfate (TBAHS) or tetrabutylammonium hydroxide.

In addition to the above-mentioned ionic conductive agents, acid acceptors such as calcium hydroxide, magnesium oxide, calcium oxide, red lead and litharge, and vulcanizing agents such as peroxide, bisphenol A, bisphenol AF and hexamethylenediamine. Can be appropriately blended as necessary. As will be described later, the vulcanizing agent is preferably blended each time the coating liquid of the rubber composition of the present invention is used (before coating).

Next, the coating liquid of the rubber composition of the present invention is prepared by using the above materials, for example, by the following method.

That is, first, the fluororubber is dissolved in a solvent. Examples of the solvent include ethyl acetate, methyl ethyl ketone, methanol, toluene, isopropyl alcohol, methyl cellosolve, and dimethylformamide. These may be used alone or in combination of two or more. Then, in the dissolved fluororubber, at least one of the reactive silicone oil (a component) and the reactive fluoro oil (b component), and optionally a non-reactive silicone oil (c component) and a non-reactive fluoro oil. (D
Ingredients) and other ingredients. Then, stirring is performed under heating to increase the viscosity, and when the viscosity becomes constant, the stirring is stopped to prepare a coating liquid of the rubber composition. The heating conditions are preferably in the range of 40 ° C or higher and not higher than the boiling point of the solvent, and particularly preferably in the range of 50 to 80 ° C. At the time of this preparation, no vulcanizing agent was added,
It is preferable to mix before use (before coating). It is speculated that the increase in viscosity during stirring is due to the finer particles of the reactive silicone oil or the like (increasing the total surface area) and the chemical bonding between the reactive silicone oil and the fluororubber molecules. The viscosity having the above-mentioned constant value is usually 2000 to 20000 cps, and preferably 3000 to 5000 cps, although it varies depending on the material used.

In the coating liquid of the rubber composition thus obtained, the particles formed from the reactive silicone oil or the like (release agent) in the fluororubber matrix (between the fluororubber molecules) have a particle size of about 50 μm or less. The particles are uniformly dispersed in particle size and are reactively fixed in the fluororubber matrix (between fluororubber molecules) (see FIG. 1). As a result,
As described above, the mold releasability is maintained for a long time without the formation of large aggregates of reactive silicone oil or the like. The particle size of the particles is preferably 0.
1 to 20 μm, particularly preferably 0.1 to 5 μm
It is.

The particle size distribution of the particles formed from the above releasing agent is as follows. That is, when the cross-sectional area of the particles having a particle diameter of 0.1 μm or more is measured and these are sequentially accumulated from the smallest, 90% of the total accumulated cross-sectional area is measured.
The particle size at the point where the cumulative cross-sectional area becomes
m or less. In addition, the said particle size says the maximum particle size. For example, regarding the particle diameter of particles having a circular cross-sectional shape, the diameter of the circle is the particle diameter, and when the cross-sectional shape is elliptical, the major axis is the particle diameter.

The above-mentioned "case in which the cross-sectional area of the particles having a particle size of 0.1 μm or more is measured and sequentially accumulated from the smallest one" means the following case. That is, in the fluororubber composition, the cross-sectional area of particles having a particle size of 0.1 μm or more distributed therein is measured. This measurement can be performed, for example, by observing the fluororubber composition with a scanning electron microscope. This fluororubber composition may be in the state of a coating liquid or in the state of being the outermost layer of the roll. Further, this observation does not have to be performed for the entire rubber composition, and may be partially performed by deciding an observation location (sampling location). This sampling point is
It is preferably 4 to 30 places, particularly preferably 20 to 30 places. Further, the calculation of the cross-sectional area is performed according to the cross-sectional shape of the particles.For example, the cross-sectional area of each particle can be calculated by dividing the particle cross-section into small parts and calculating the area of each part. it can. Then, this cross-sectional area is sequentially accumulated from the smallest one, and the total cumulative cross-sectional area is calculated.

Then, the above "for this total cumulative cross-sectional area
The particle size at the point where the cumulative cross-sectional area is 90% is 30
“It is less than or equal to μm” means the following. That is,
Derived the cumulative cross-sectional area of 90% of the total cumulative cross-sectional area
I do. And the point where the cumulative cross-sectional area is 90%
Particle size (hereinafter referred to as "90% cumulative cross-sectional area particle size")
Ask for. An example of this is shown in the graph of FIG. This gra
In the figure, the vertical axis is the cumulative cross-sectional area ratio (%) and the horizontal axis is
Particle size (μm) and particle cross-sectional area (μm ²)
You. As shown in the figure, cumulative from the smallest particle cross-sectional area
As the particle size (cross-sectional area) increases,
A curve with a large cumulative area ratio is obtained. And the point
As shown by the line, 90% cumulative cross-sectional area
The particle size is obtained. And at this point the particle size of the particles
Is 30 μm or less, it is a roll according to the present invention.
Can be determined.

Next, an example in which the roll manufacturing method of the present invention using the coating liquid of the rubber composition is applied to a developing roll will be shown.

As the developing roll, there may be mentioned one having a three-layer structure as shown in FIG. As shown in the drawing, this developing roll is provided with an innermost layer 11 and an intermediate layer 12 formed of an elastic body and an outermost layer 13 formed of a fluororubber composition on the outer periphery of a shaft body 10 such as a cored bar. There is.

This developing roll having a three-layer structure is manufactured by the method of manufacturing a roll of the present invention as follows. That is, first, materials for forming the innermost layer and the intermediate layer are prepared.

The components of the material for forming the innermost layer and the intermediate layer are not particularly limited, and conventionally known ones are used.

For example, as the material for forming the innermost layer, there may be mentioned a mixture of ethylene propylene rubber (EPDM), styrene butadiene rubber (SBR), silicone rubber, polyurethane elastomer and the like with carbon black.

As the material for forming the intermediate layer, for example, EPDM, SBR, nitrile rubber, hydrogenated nitrile rubber, polyurethane elastomer, polyester, N
-Methoxymethylated nylon and the like mixed with a conductive agent such as carbon black, metal oxide, and quaternary ammonium salt.

As a method for preparing the materials for forming the innermost layer and the intermediate layer, a conventionally known method is applied. To give an example of this, first, the innermost layer forming material (compound)
Is prepared by kneading the above components with a kneader such as a kneader. In addition, the material for forming the intermediate layer (coating liquid)
Is prepared by kneading with a ball mill, rolls or the like, adding a solvent to this mixture, and mixing and stirring.

Then, the innermost layer and the intermediate layer are formed on the outer periphery of the shaft by a conventional method to prepare a roll substrate. For example, as shown in FIG. 7, the lower lid 15 on which the shaft body 10 is set
Then, a compound-like innermost layer forming material is cast into the cylindrical mold 16, and the upper lid 17 is fitted onto the cylindrical mold 16. In this state, the entire roll die is heated (vulcanization treatment, conditions: 150-
200 ° C. × 20 to 40 minutes) to form the innermost layer. Then, the shaft body on which the innermost layer is formed is released from the mold, and the residue of the vulcanizing agent is removed by evaporation if necessary. Then, the intermediate layer forming material (coating liquid) is applied to the outer peripheral surface of the innermost layer, and drying and heat treatment (vulcanization treatment, condition: 120 to 200 ° C. × 1)
0 to 30 minutes) to form an intermediate layer. The above coating is
Conventionally known coating methods such as a dipping method, a spray method and a roll coating method can be applied. In this way, a roll substrate having the innermost layer and the intermediate layer formed on the outer periphery of the shaft body is manufactured.

On the other hand, a vulcanizing agent is added to the rubber composition (coating liquid) of the present invention. Then, the rubber composition is applied to the outer peripheral surface of the intermediate layer of the roll substrate. This coating method is not particularly limited, and a conventional method such as a dipping method, a spray method or a roll coating method can be applied.
Then, after the coating, drying and heat treatment (vulcanization treatment, conditions: 150 to 200 ° C. × 20 to 40 minutes) are performed to remove the solvent in the rubber composition by evaporation and to crosslink the fluororubber component. . In this way, a developing roll having a three-layer structure as shown in FIG. 6 can be manufactured. In this developing roll, the thickness of each layer is appropriately determined, but the thickness of the innermost layer is preferably set in the range of 2 to 10 mm, particularly preferably 3 to 6 mm. The thickness of the intermediate layer is preferably set in the range of 3 to 90 μm, and particularly preferably 5 to 15 μm. The thickness of the outermost layer is preferably 20 to 100 μm, particularly preferably 30 to 70 μm.

In this way, a developing roll can be produced by the roll producing method of the present invention, but the present invention is not limited to this. That is, the manufacturing method of the roll of the present invention,
The present invention can be applied to any roll of the type in which the roll surface is in direct contact with the toner, because excellent toner releasability can be imparted to the roll surface for a long time. Examples of such a roll include a fixing roll and the like.

[0067]

As described above, the roll manufacturing method of the present invention uses a special fluororubber coating liquid. The coating liquid of the special fluororubber composition is obtained by the special production method. Therefore, in the coating solution of this fluororubber composition, particles formed of reactive silicone oil or the like are uniformly dispersed, the particle size of the particles is about 50 μm or less, and The reaction has been fixed. Then, the coating liquid of this special fluororubber composition is applied to the roll base to form the outermost layer, whereby the target roll is obtained. And, for example, if the roll manufacturing method of the present invention is applied to a developing roll,
It is possible to prevent the generation of large aggregates such as silicone oil which is a toner release agent and the exudation onto the roll surface, which are problems in the conventional developing roll. As a result, with this developing roll, the occurrence of toner filming is prevented, and a good quality copied image can be obtained for a long period of time.

Next, examples will be described together with comparative examples.

First, prior to Examples and Comparative Examples, a core metal (diameter 10 mm, made of SUS304) to be a shaft, a liquid silicone rubber to which carbon black was added as an innermost layer forming material, and an intermediate layer forming material A product prepared by adding carbon black to hydrogenated nitrile rubber was prepared.

Then, according to the above-mentioned method, the innermost layer and the intermediate layer were formed on the outer periphery of the shaft body to prepare a roll substrate.

[0071]

Examples 1 to 7 and Comparative Examples 1 to 4 The outermost layer was formed on the outer peripheral surface of the roll substrate by the method described above. That is, the materials shown in Tables 1 to 3 below were mixed in the proportions shown in the same table, and a coating solution of the fluororubber composition was prepared according to the method described above. Then, using this, the outermost layer was formed on the outer peripheral surface of the roll base by the above-mentioned method (coating method: roll coating method), and the intended developing roll was produced. The thickness of the innermost layer of this developing roll is 5 mm.
The thickness of the intermediate layer is 10 μm, and the thickness of the outermost layer is 50 μm.

The developing rolls of Examples 1 to 7 and Comparative Examples 1 to 4 thus obtained were examined for evaluation of copied images and occurrence of toner filming by the following method. The results are also shown in Tables 1 to 3 below. Further, in the same table, the average particle size of the particles and the 90% cumulative cross-sectional area particle size are also shown. The 90% cumulative cross-sectional area grain size was measured by the method described below.

[Evaluation of Copy Image] The developing roll was incorporated in an electrophotographic copying machine to actually perform copying. Then, the image quality of the copied image was visually evaluated at the initial stage of copying and after copying 30,000 sheets. That is, the characters are printed and there is no problem in the copied image,
The fine lines were clearly copied, and the fine lines and fogging were marked with x. It should be noted that the faint means that the fine line is broken, and the fog means that the toner is scattered in a place where there is no image. In addition, when toner filming occurred, evaluation was performed separately for a portion where toner filming occurred and a portion where toner filming did not occur.

[Toner Filming] In a portion where the toner thickly adheres to the surface of the developing roll, the charging property is deteriorated and a defective copy image occurs. Specifically, if a part of the toner component adheres to the surface of the developing roll with a thickness of 1 μm or more, the image is significantly deteriorated. Therefore, when the toner adhesion is 1 μm or more, the toner filming is considered to have occurred.

[90% cumulative cross-sectional area particle size] As shown in FIG. 9A, two breaks are made in the elastic body portion (inner layer, intermediate layer, outermost layer) of the developing roll 20 at right angles to the axial direction. To make a sample, and a slit was made in the axial direction to take out from the cored bar to prepare a sample 20a as shown in FIG. Then, as shown in the cross-sectional view of the sample 20a in FIG.
Observation was performed with a scanning electron microscope (S-4100, manufactured by Horiba, Ltd.). And 90% by using the image processor (Spica II, manufactured by Nippon Avionics Co., Ltd.) according to the procedure described above.
The cumulative cross-sectional area grain size was automatically determined.

[0076]

[Table 1]

[0077]

[Table 2]

[0078]

[Table 3]

From the above Tables 1 and 2, in Examples 1 to 7, the 90% cumulative cross-sectional area particle size of the particles of reactive silicone oil etc. was 30 μm or less. Further, each of the developing rolls of Examples 1 to 7 had no problem in copied images, fine lines were clearly copied, and toner filming did not occur. On the other hand, from Table 3 above, Comparative Example 1
In Nos. 4 to 9, the 90% cumulative cross-sectional area particle diameter of the particles of reactive silicone oil etc. exceeded 30 μm. Then, in the developing rolls of Comparative Examples 1 to 4, toner filming occurred, and the copied image was bad in this portion.

Next, the state of the particles formed from the reactive silicone oil in the outermost layer of the developing rolls of Example 1 and Comparative Example 1 was examined by using the scanning electron microscope, and the results are shown in FIGS. Shown in the photo.

FIG. 2 is a photograph (magnification: 10,000 times) showing the state of the surface of the outermost layer of the developing roll of Example 1, and FIG.
It is a photograph (magnification: 10,000 times) showing a state inside the same outermost layer (cross section in the axial direction). FIG. 4 is a photograph (magnification: 10,000 times) showing the state of the surface of the outermost layer of the developing roller of Comparative Example 1.
FIG. 5 is a photograph (magnification: 10,000 times) showing a state inside the same outermost layer (cross section in the axial direction). From the photographs of FIG. 2 and FIG.
In the developing roll of Example 1, the particles formed from the reactive silicone oil have a very small particle size of about 1 μm or less, and it can be seen that they are uniformly dispersed in the fluororubber matrix. On the other hand, from the photographs of FIGS. 4 and 5,
It can be seen that in the developing roll of Comparative Example 1, the particle size of the particles formed from the reactive silicone oil is large.

Judging from the results of these electron microscope observations and the results of Tables 1 to 3 (toner filming), the particles formed from the reactive silicone oil dispersed in the fluororubber matrix were evaluated. It can be said that the 90% cumulative cross-sectional area particle size is 30 μm or less, and this is reactively fixed in the fluororubber matrix, so that in the developing roller of the example, the occurrence of toner filming was prevented.

[Brief description of drawings]

FIG. 1 is a schematic view showing a microscopic structure of a fluororubber composition of the present invention.

FIG. 2 is a photograph showing the structure of particles formed from reactive silicone oil on the surface of the outermost layer of the developing roll that is an example of the present invention.

FIG. 3 is a photograph showing the structure of particles formed from a reactive silicone oil inside the outermost layer of the developing roll that is an example of the present invention.

FIG. 4 is a photograph showing the structure of particles formed from reactive silicone oil on the surface of the outermost layer of a conventional developing roll.

FIG. 5 is a photograph showing the structure of particles formed from a reactive silicone oil inside the outermost layer of a conventional developing roll.

FIG. 6 is a cross-sectional view showing the structure of a developing roll.

FIG. 7 is a cross-sectional view showing a method of manufacturing a developing roll.

FIG. 8 is a graph showing the relationship between the particle size of particles and the cumulative cross-sectional area ratio of particles.

9A is a perspective view showing a state in which a developing roll is cut, FIG. 9B is a perspective view of a sample cut out from the developing roll, and FIG. 9C is a sectional view of the sample. .

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[Procedure amendment]

[Submission date] October 2, 1995

[Procedure Amendment 1]

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[Procedure 3]

[Document name to be amended] Drawing

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[Figure 5]

Continuation of front page (72) Inventor Akihiko Kaji 3600 Gyokutsuyama, Komaki City, Aichi Tokai Rubber Industry Co., Ltd.

Claims (5)

[Claims] 1. A method for producing a roll, which comprises applying a coating solution of a fluororubber composition to the outer peripheral surface of a roll substrate and then vulcanizing the coating solution to form an outermost layer of fluororubber. A method for producing a roll, which comprises using the following (A) as a coating liquid. (A) Fluorine rubber dissolved in a solvent is mixed with at least one of reactive silicone oil and reactive fluorine oil and stirred under heating to increase the viscosity, and when the viscosity becomes constant, the stirring is stopped. A coating liquid of the fluororubber composition prepared by. 2. The reactive silicone oil is a reactive silicone oil having at least one reactive group selected from the group consisting of hydroxyl group, amino group, mercapto group, epoxy group, carboxyl group and methacryl group,
The roll of claim 1, wherein the reactive fluorine oil is a reactive fluorine oil having at least one reactive group selected from the group consisting of a hydroxyl group, an amino group, a mercapto group, an epoxy group, a carboxyl group and a methacryl group. Manufacturing method. 3. The method for producing a roll according to claim 1, wherein the heating condition is in the range of 40 to 150 ° C. 4. The roll according to claim 1, wherein the reactive silicone oil has an average molecular weight of 300 to 150,000 and the reactive fluorine oil has an average molecular weight of 200 to 20,000. Manufacturing method. 5. The total blending ratio of the reactive silicone oil and the reactive fluorine oil is such that the fluororubber 10
0.5 to 100 parts by weight with respect to 0 parts by weight.
4. The method for manufacturing the roll according to any one of 4 to 4.