KR20070033903A - Rubber member for electrophotographic image forming and electrophotographic image forming apparatus - Google Patents

Abstract

According to the invention,

(A) organopolysiloxane represented by the following formula (1),

(B) a filler having an average particle diameter of 2 to 200 µm having a shin morse hardness of 4.0 or less, and

(C) curing agent

A silicone rubber obtained by curing a silicone rubber composition containing a silicone rubber composition, wherein the rubber surface is subjected to polishing or cotton wear or surface friction in an environment of use, thereby crushing or dropping the filler of component (B), Rz ratio of the surface roughness (X) of the silicone rubber obtained by hardening the composition from which the (B) component was removed from the surface roughness (X) and the silicone rubber composition after the recessed hole of the said silicone rubber was formed ( The rubber member for electrophotographic image formation which has many recessed holes in the surface whose X / Y) is 1.2 or more can be provided.

R _n SiO _{(4-n) / 2}

In the formula, R is a monovalent hydrocarbon group and n is 1.95 to 2.05.

Moreover, according to this invention, the image forming rubber member for office equipment provided with many concave holes in the rubber surface can be provided.

 Organopolysiloxane, silicone rubber composition, rubber member for electrophotographic image formation

Description

Rubber member for electrophotographic image forming and electrophotographic image forming apparatus {RUBBER COMPONENTS FOR ELECTROPHOTOGRAPHIC IMAGING AND ELECTROPHOTOGRAPHIC IMAGING APPARATUS}

[Patent Document 1] Japanese Unexamined Patent Publication No. 6-221321

[Patent Document 2] Japanese Patent Application Laid-Open No. 2002-338808

The present invention provides an electrophotographic image forming rubber member in which a plurality of concave holes are provided on the rubber surface by grinding or surface wear of the cured silicone rubber or by surface friction in a use environment, whereby the blended filler is crushed or dropped. It is about. In particular, when used in the developing roll, the surface roughness becomes rough, and the physical conveyance force of the toner can be expected to increase, and even when the rubber member such as the toner blade or the paper feed roll, which may cause surface wear, is used continuously, the surface state changes. The present invention relates to a rubber member for electrophotographic image forming, which is low in number, can sustain initial characteristics, and can withstand long-term use, and an electrophotographic image forming apparatus using the same.

As a method of imparting irregularities to the surface of silicone rubber, various methods of imparting irregularities by adding a filler having a large particle size have been used. For example, pulverized quartz, spherical fused silica, calcined diatomaceous earth, spherical glass, alumina, or the like is added, and the surface roughness is roughened by polishing or abrasion of the rubber surface, or the mattness and the extrusion characteristics are improved. Usually, as a filler added in order to roughen such surface roughness, addition of the filler which has a particle diameter of about 2-500 micrometers is necessary. By the addition of such a filler having a large particle size, the rubber surface remains convex surface with the added filler remaining on the rubber surface, and the filler particles protrude from the rubber surface. Therefore, since the filler contacts the counterpart base material, the counterpart base material in contact with the rubber may be scratched or scraped, and there is a risk of scratching the resin such as plastic or the like.

Therefore, as a method of imparting concavities and convexities to the rubber surface without increasing scratches on the counterpart (OPC drum) in developing roll applications and increasing the toner conveying force, it is described in Japanese Patent Application Laid-Open No. 6-221321. Similarly, a material that satisfies the above characteristics by adding silicone rubber powder or the like has been proposed.

However, the rubber material to which the silicone rubber powder is added is an effective means for forming the surface irregularities, but has little effect on the wear resistance, and if the frictional state is maintained, the irregularities are eliminated or the particle size distribution of the added silicone rubber powder If the width becomes wider, the uniformity of the surface irregularities is lost and the surface roughness of the developing roll or the like becomes large, so that it may not be possible to cope with the recent high resolution of the printer.

Moreover, as a method aimed at improving the abrasiveness and wearability of the developing roll, a roll material having a roll durability by adding a filler having a Mohs hardness of 2 to 8 has been proposed, as in JP-A-2002-338808. .

However, these silicone materials are not intended to impart the surface roughness of the roll, and there is no description that surface roughness is imparted by the addition of the filler.

This invention is made | formed in view of the said situation, The surface roughness is improved by giving a uniform number of concave holes to a rubber surface, (i) Improvement of conveyance or adhesive force of physical powder etc. by a concave hole, (ii) The performance of providing slip property by the concave hole, securing a stable contact surface, (iii) removing the water film or oil film by the concave hole, improving the cleanability, and the like, and forming an electrophotographic image having a large number of concave holes in the surface An object of the present invention is to provide a rubber member for use and an electrophotographic image forming apparatus using the same.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to achieve the said objective, the present inventors mix | blended the filler which has a new Morse hardness of 5.0 or less and an average particle diameter of 2-200 micrometers, and hardened rubber surface is grind | polishing or cotton wear, or in the environment of use. By surface friction, the blended filler is pulverized or dropped, and a large number of concave holes are provided on the rubber surface, and it is found that the rubber member for electrophotographic image formation is useful for various rolls, especially a developing roll material, and the like. Came to complete.

That is, this invention provides the electrophotographic image forming rubber member which has a recessed hole in the following surface, and the electrophotographic image forming apparatus using the same.

[1] (A) organopolysiloxane represented by the following formula (1): 100 parts by mass,

(B) a filler having an average particle diameter of 2 to 200 µm having a new Morse hardness of 5.0 or less: 5 to 200 parts by mass, and

(C) Curing agent: Curing effective amount

And a silicone rubber obtained by curing a silicone rubber composition containing a silicone rubber composition, wherein the rubber surface is subjected to polishing or surface abrasion or surface friction in an environment of use so that the filler, which is the component (B), is pulverized or dropped. Rz ratio of the surface roughness (X) of the silicone rubber obtained by hardening the composition from which the (B) component was removed from the surface roughness (X) and the silicone rubber composition after the recessed hole of the said silicone rubber was formed ( X / Y) is 1.2 or more, The rubber member for electrophotographic image forming which has many recessed holes in the surface.

<Formula 1>

R _n SiO _{(4-n) / 2}

In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group, n is a positive number of 1.95 to 2.05.

[2] The rubber member for electrophotographic image forming according to the above [1], wherein the total area of the concave hole portions of the rubber surface is 15% or more of the entire rubber surface area when measured by an electron micrograph.

[3] The aforementioned [1] or [2], wherein the component (B) is adjusted so that the proportion of the filler having a particle size of 5 times or more to the average particle diameter of the filler measured by laser diffraction scattering is 2.3 mass% or less. It is a filler which has a particle size distribution, The rubber member for electrophotographic image forming characterized by the above-mentioned.

[4] The rubber member for electrophotographic image forming according to any one of [1] to [3], wherein the filler is calcium carbonate, sodium chloride or aluminum hydroxide and has an average particle diameter of 2 to 70 µm.

[5] The rubber member for electrophotographic image forming according to any one of the above [1] to [4], wherein the silicone rubber composition is a rubber material to which conductivity is imparted, further comprising (D) a conductive material.

[6] The electronic photograph according to any one of [1] to [5], for a toner blade, a developing roll, a toner conveying roll, a paper conveying roll, an intermediate transfer roll, a fixing roll, a developing belt, an intermediate transfer belt, or a fixing belt. Rubber member for type image formation.

[7] An electrophotographic image forming apparatus comprising the rubber member for electrophotographic image forming according to [6].

Best Mode for Carrying Out the Invention

In the present invention, the organopolysiloxane of the component (A) is represented by the following formula (1).

<Formula 1>

R _n SiO _{(4-n) / 2}

In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group, n is a positive number of 1.95 to 2.05.

In Formula 1, R is a substituted or unsubstituted monovalent hydrocarbon group, preferably having 1 to 12 carbon atoms, particularly 1 to 8 carbon atoms. Examples of the monovalent hydrocarbon group represented by R include, for example, a methyl group, an ethyl group, Alkyl groups, such as an alkyl group, such as a propyl group, a butyl group, a hexyl group, and a dodecyl group, a cycloalkyl group, such as a cyclohexyl group, a vinyl group, an allyl group, butenyl group, and a hexenyl group, an aryl group, such as a phenyl group and a tolyl group, and beta Aralkyl groups, such as -phenylpropyl group, or the chloromethyl group, trifluoropropyl group, cyanoethyl group, etc. which substituted some or all of the hydrogen atoms couple | bonded with the carbon atom of these groups by the halogen atom, the cyano group, etc. are mentioned. . In addition, n is a positive number of 1.95 to 2.05. It is preferable that the said organopolysiloxane has the molecular chain terminal blockade by the trimethylsilyl group, the dimethylvinyl silyl group, the dimethylhydroxy silyl group, the trivinyl silyl group, etc.

The organopolysiloxane preferably has two or more alkenyl groups in the molecule, and it is preferable that 0.001 to 5 mol%, particularly 0.01 to 0.5 mol%, in R is an alkenyl group, in particular a vinyl group. In particular, when a combination of a platinum-based catalyst and an organohydrogenpolysiloxane is used as a curing agent to be described later, an organopolysiloxane containing such an alkenyl group is usually used.

In addition, the organopolysiloxane is a co-hydrolytic condensation of one or two or more of the organohalogenosilanes that are usually selected, or an alkaline or acidic catalyst of a cyclic polysiloxane (such as a trimer or tetramer of siloxane). It can be obtained by ring-opening polymerization using, which is basically linear diorganopolysiloxane, but may be partially branched. Also, two or more kinds of mixtures having different molecular structures may be used. Moreover, it is preferable that the viscosity of the said organopolysiloxane is 100 mPa * s or more in 25 degreeC by JISK6249. More preferably, it is 100,000-10,000 mPa * s. It is preferable that polymerization degree is 100 or more, especially 3,000 or more, The upper limit becomes like this. Preferably it is 100,000, More preferably, it is 10,000.

Next, the filler of (B) component is demonstrated.

Unlike the reinforcing fillers, such as reinforcing silica, generally, the filler of this invention is added for the purpose of giving a uniform concave hole to a roll surface, and a new morse hardness (classified by 1-15 according to the level of hardness). The filler whose value is 5.0 or less is added to (A) component, and it mixes.

The present invention provides a plurality of recesses on the rubber surface by curing the silicone rubber composition to which the filler of component (B) is added, and then crushing or dropping the filler by grinding or polishing the surface of the rubber or by bringing the surface into rubbing in the use environment. It becomes possible to give a hole. Therefore, it is more preferable that the filler is easily separated and dropped from the silicone rubber, and the filler is crushed by polishing or abrasion. The shape, properties, and the like of the filler of component (B) are not particularly defined, but as the filler preferably used in the present invention, spherical or pulverized, tetrahedral or more crystalline, and prismatic particles are preferable. Specific examples include metal oxides such as aluminum hydroxide, calcium carbonate (calcite), sodium chloride, fluorite powder, rock salt powder, gypsum powder, amorphous graphite, spherical graphite, and metal aluminum powder, but more preferably polishing or surface abrasion. Preference is given to substances in which the particles can be ground, and calcium carbonate, sodium chloride and aluminum hydroxide are preferred. Substances that are characteristic of metals and the like are not particularly desirable. In addition, conductive fillers (metal fine particles, conductive metal oxide fine particles, graphite, etc.) can also be used.

In addition, it is preferable that the new Morse hardness is 5.0 or less, and, as for the hardness of the filler itself, it is more preferable that it is three or less. If the filler is too hard, the powder may be hardly dropped or pulverized by polishing or the like, and the filler may remain convex on the surface and scratch the counterpart material in contact with the silicone rubber.

The average particle diameter of the filler used here is a size of 2 to 200 μm, measured by laser diffraction scattering based on JIS R 6002, preferably 2 to 100 μm, more preferably 2 to 70 μm, particularly preferably 5 To 70 μm.

Moreover, in order to have a uniform concave hole, it is preferable to use a thing with narrow particle size distribution, and the ratio of the filler which has a particle size 5 times or more with respect to an average particle diameter is 2.3 mass% or less, More preferably, 1 mass% or less It is preferable that it is a filler which has a particle size distribution adjusted to be. By the addition of fillers having a narrow particle size distribution, more concave holes can be made in the surface with the addition of less fillers.

In particular, when the particle size distribution of the filler is determined to be a normal distribution N (μ, σ ² ), a powder having a dispersed state in which particles of 95.4% by mass or more of the filler is contained in a normal distribution range of N (μ, 2μ ² ) is preferable. More preferably, σ is a powder having a sharp normal distribution within 1 times the average particle diameter, provided that μ is the average particle diameter of the filler, and that the standard deviation σ of the normal distribution is 2 times the average particle diameter μ or 1 Within twice the value].

The method for producing the powder (filler) having the above-mentioned particle size distribution is not particularly defined, but a method of chemically pulverizing the filler obtained by pulverizing and classifying the process, the filler obtained by using the emulsion as a starting material, a metal, a resin, or the like by high temperature melting and pulverization Although the method by the crystal growth by synthesis | combination, etc. are mentioned, Especially the chemical synthetic product which can manage powder particle size distribution in a narrow range, the pulverized product which cut | disconnected the crude particle and the fine powder is used preferably.

Particularly preferably used as such fillers are powders such as calcium carbonate, aluminum hydroxide, sodium chloride and the like.

It is preferable that the addition amount of (B) component shall be 5-200 mass parts, especially 5-100 mass parts with respect to 100 mass parts of (A) component. More preferably, it is 10-70 mass parts. If it is less than 5 mass parts, sufficient concave hole cannot be obtained, and when it exceeds 200 mass parts, not only the fall of a rubber physical property is remarkable but it is also difficult to mix | blend itself.

The filler can also be surface treated with a silane, silicone oil, hydrocarbon oil, wax or the like for the purpose of more easily falling off the cured silicone rubber.

In this invention, a hardening | curing effective amount is mix | blended as a (C) component. As a hardening | curing agent of (C) component, the combination of a well-known platinum-type catalyst and organohydrogen polysiloxane, or an organic peroxide catalyst can be used. A well-known thing can be used as a platinum type catalyst, Specifically, a platinum element substance, a platinum compound, a platinum complex, a chloroplatinic acid, an alcohol compound of chloroplatinic acid, an aldehyde compound, an ether compound, complexes with various olefins, etc. are illustrated. It is preferable to make the addition amount of a platinum-type catalyst into the range of 1-2,000 ppm as a platinum atom with respect to the organopolysiloxane of (A) component.

The organohydrogenpolysiloxane used in combination with the platinum-based catalyst may be any one of linear, branched and cyclic, but preferably has a degree of polymerization of 300 or less, and diorganopolysiloxane and dimethyl end-blocked with dimethylhydrogensilyl groups. copolymer, dimethyl hydrogen siloxane units _{(H (CH 3) 2 SiO} 0 .5 ) of the siloxane units and methyl hydrogen siloxane units and terminal trimethylsiloxy units and SiO ₂ Low viscosity fluid comprising units, 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane, 1-propyl-3,5,7-trihydrogen-1, 3,5,7-tetramethylcyclotetrasiloxane, 1,5-dihydrogen-3,7-dihexyl-1,3,5,7-tetramethylcyclotetrasiloxane and the like are exemplified. The addition amount of organohydrogenpolysiloxane as said hardening | curing agent is used so that the hydrogen atom (SiH group) directly bonded to the silicon atom may be 50-500 mol% with respect to the alkenyl group of the organopolysiloxane of (A) component. desirable.

As the organic peroxide catalyst, organic peroxides such as alkyl peroxides such as di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and aralkyl peroxides such as dicumylperoxide Can be mentioned.

It is preferable that the usage-amount of an organic peroxide shall be 0.1-10 mass parts with respect to 100 mass parts of said (A) component.

Moreover, addition bridge | crosslinking and organic peroxide bridge | crosslinking can also be used together. As crosslinking agent for liquid materials, addition crosslinking is recommended.

In addition, it is arbitrary to add an electroconductive substance as (D) component, and to make it an electroconductive rubber composition. Although the kind and compounding quantity of a conductive material are not restrict | limited, Conductive carbon black, electroconductive metal oxide type particle | grains, for example, electroconductive galvanization, electroconductive titanium oxide, etc. can be used, A 1 type, or 2 or more types of conductive material can also be used together. .

As the carbon black, those commonly used in conductive rubber compositions can be used, and for example, acetylene black, conductive furnace black (CF), super conductive furnace black (SCF), extra conductive furnace black (XCF), Conductive channel black (CC), furnace black or channel black heat-treated at a high temperature of about 1,500 to 3,000 ° C. Specifically, as acetylene black, Denka Black (manufactured by Denki Chemical Industries, Ltd.), Shaungan Acetylene Black (manufactured by Shaungan Chemical Co., Ltd.), and the like, as Conductive Furnish Black, Continex CF (manufactured by Continental Carbon), Balkan C (manufactured by Cabot Co., Ltd.), Continex SCF (manufactured by Continental Carbon Co., Ltd.), Balkan SC (manufactured by Cabot Co., Ltd.), etc. as super conductive furnace black, and Asahi HS-500 (manufactured by Asahi Carbon Co., Ltd.) as extra conductive furnace black ) And Balkan XC-72 (manufactured by Cabot) include Kourax L (manufactured by Degussa) as the conductive channel black, and Ketjen Black EC and Ketjen Black EC-600JD (Ketjen Black), which are two types of furnace blacks. International Corporation) can also be used. The furnace black has an amount of impurities, in particular sulfur or sulfur compounds, of 6,000 ppm or less, more preferably 3,000 ppm or less, in the concentration of elemental sulfur. In addition, among these, acetylene black has a low impurity content and has a developed secondary structure structure, which is excellent in electroconductivity and is therefore particularly preferably used in the present invention. Moreover, Ketjen Black EC, Ketjen Black EC-600JD, etc. which show the electroconductivity excellent also in the low charge amount from the outstanding specific surface area can also be used preferably.

Although the addition amount of the said conductive substance should just be an amount which becomes the resistance value which the rubber | gum of a conductive silicone rubber composition becomes a conductive state, ie, a volume resistivity of 10 ¹⁴ ohm * m or less, 1-100 with respect to 100 mass parts of (A) component mentioned above. It is preferable to set it as mass parts, especially 5-50 mass parts. If the added amount is less than 1 part by mass, the desired conductivity may not be obtained. If it exceeds 100 parts by mass, physical mixing may be difficult or the mechanical strength may be lowered, so that the desired rubber elasticity may not be obtained.

It is preferable to add reinforcing silica fine powder to the rubber composition of this invention as needed. Fine silica powder is required to obtain a rubber composition having excellent mechanical strength, for which purpose, the specific surface area is at least 10 m ² / g, preferably 50 to 400 m ² / g. Examples of the fine silica powder include fumed silica (dry silica) and precipitated silica (wet silica), and fumed silica (dry silica) is preferable. When these usable reinforcing silicas are illustrated as a commercial item, Aerosil 130, 200, 300, 380 (made by Nippon Aerosil Co., Ltd. brand name), Cab-O-sil MS-5, MS-7, HS-5, HS- 7 (manufactured by Cabot, trade name), Santocel FRC, CS (manufactured by Monsanto Corporation, trade name), Nibsil VN-3 (manufactured by Nippon Silica Co., Ltd., trade name) and the like. Furthermore, these surfaces can also be hydrophobized by organopolysiloxane, organopolysilazane, chlorosilane, alkoxysilane, or the like. These silicas may be used alone or in combination of two or more. In addition, the addition amount of the said fine silica powder is not exact, Preferably it is the range of 5-200 mass parts per 100 mass parts of organopolysiloxane. If it is less than 5 parts by mass, too little to obtain a sufficient reinforcing effect, if more than 200 parts by mass, workability is poor, preferably 5 to 100 parts by mass, more preferably 5 to 90 parts by mass, particularly preferably 10 to 50 parts by mass.

In addition, it is optional to add a filler as an extender having a particle size smaller than that of the filler of component (B) having a new morse hardness greater than 5.0, for example, pulverized crystalline silica or fine diatomaceous earth powder.

As other additives, if necessary, additives such as heat improvers such as colorants and iron octylate, halogen compounds imparting flame retardancy, hydroxyl agents, iron oxides, cerium oxide, and thermal conductivity enhancers, mold release agents, alkoxysilanes, and polymerization degrees (A) component Dispersing agents such as lower dimethylsiloxane oil, silanol, for example, both terminal silanol-blocked low molecular siloxanes such as diphenylsilanediol, various carbon functional silanes for improving adhesion and molding processability, silicone crosslinking, etc. are inhibited. Although hardening and uncured olefin elastomers etc. which are not hardened | cured may be mixed and added, when adding is a particulate form, it is preferable that particle diameter is smaller than the filler of (B) component.

The rubber composition of the present invention can be obtained by uniformly mixing the above components using a mixer of polymer and powder such as a biaxial roll, a Benbury mixer, a dough mixer (kneader), a Shinagawa mixer, a planetary mixer, and the like. The rubber composition thus produced can be easily obtained by heat-curing by a known method. The curing method may be a method of applying heat required for crosslinking of the rubber, and the molding method is not particularly limited, such as continuous vulcanization by extrusion molding, press molding, or mold molding by injection. In this case, it is preferable that heating temperature is 70-500 degreeC, especially 120-300 degreeC, and time is several second-1 hour, especially 10 second-30 minutes. If necessary, the secondary vulcanization may be performed at 100 to 200 ° C. for about 1 to 20 hours.

After the rubber member of the present invention cures the silicone rubber composition to obtain a silicone rubber, the surface of the silicone rubber is polished or worn out, or the surface friction is used in an environment of use, so that the rubber component of the component (B) in the silicone rubber composition The filler is crushed or dropped to form a plurality of concave holes in the silicone rubber surface. In this case, it is effective that the surface is smooth, there are no projections, and the surface has a large number of concave holes.

Here, the grinding | polishing can employ | adopt methods, such as the cylindrical grinding machine used for grinding | polishing of rolls, a square cylindrical grinding machine, a circular disk board grinding | polishing apparatus, a roll film grinding | polishing apparatus, and a super finisher grinding | polishing apparatus. Surface wear can employ methods such as lap polishing with a polishing tape or sheet, polishing pads, belt polishing, barrel polishing, and the like.

In addition, surface rubbing in a use environment means that a flat surface such as a metal surface or a plastic surface and the rubber member are in contact with each other or constantly moving, and as a result, the rubber contact surface is worn.

In addition, the concave holes are formed uniformly on the rubber surface, in which case in the electron micrograph (preferably 50 to 5,000 times magnification, in particular 100 to 1,000 times), the total area of the concave hole portions of the rubber surface is the total surface area. Is 15% or more, more preferably 30 to 80%, still more preferably 50 to 70%. In addition, the said area ratio is an average of three measured values.

In addition, the measured value at the time of measuring the roughness Rz of the surface of the silicone rubber in which the said concave hole was formed as 10-point average roughness according to JIS B0601-1994, and of (B) component from the silicone rubber composition for obtaining the said silicone rubber When the measured value when the roughness Rz of the surface of the silicone rubber obtained by curing the composition excluding the filler under the same conditions as in the case of obtaining the above silicone rubber is measured in the same manner as above, the ratio of X and Y [Rz ratio = X / Y] is 1.2 or more, preferably 1.4 or more, more preferably 2.0 or more. If X / Y is smaller than 1.2, the hole is not in a sufficiently empty state.

Moreover, it is also useful to surface-treat or surface-coat with the various resin, elastomer, monomer, etc. on the surface which has the concave hole of the rubber member obtained by this invention. In the case of a thin film coating having a coating thickness of several μm or less, the concave holes of the rubber member become the remaining surface layer, and the characteristics of the surface roughness of the member remain, and in the case of a thick film coating having a coating thickness of several tens of micrometers or more, By the anchor effect and the effect of increasing the adhesion surface area, it becomes possible to form a coated surface that is firmly adhered and adhered.

The electrophotographic image forming rubber member of the present invention is preferably used as a toner blade, a developing roll, a toner conveying roll, a paper conveying roll, an intermediate transfer roll, a fixing roll, a developing belt, an intermediate transfer belt, a fixing belt, and the like.

<Example>

Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following Example. The part shown by the Example and the comparative example shows all a mass part, an average particle diameter is measured by the laser diffraction scattering based on JISR6002, and a viscosity is the viscosity in 25 degreeC measured based on JISK6249.

<Example 1>

100 parts of organopolysiloxane containing 99.825 mol% of dimethylsiloxane units and 0.15 mol% of methylvinylsiloxane units and having a viscosity of 1 × 10 ⁷ mPa · s sealed at both ends of the molecular chain with 0.025 mol% of dimethylvinylsilyl groups, acetylene 12 parts of denka black (40 nm, manufactured by Denki Chemical Industries, Ltd.) and 10 parts of fumed silica (200 aerosols, manufactured by Nippon Aerosil Co., Ltd.) having a specific surface area of 200 m ² / g, and a dispersant 2 parts of both terminal silanoldimethylpolysiloxane polymers having an average degree of polymerization of 3 to 10, and 40 parts of pulverized heavy calcium carbonate A (powder A) having an average particle diameter of 10 µm as a filler and a Shin Mohs hardness of 3.0 as a pressurized kneader. After kneading, 2 parts of 25 mass% silicone paste of 2,5-dimethyl-bis- (2,5-t-butylperoxy) hexane was added as a curing agent to 100 parts of the base compound to prepare a silicone rubber composition. .

The composition was then molded around a core 6 mm in diameter into a 6 mm thick, 18 mm diameter, 50 mm long roll and 2 mm thick sheet. In addition, the molding conditions at this time were postcure 200 degreeC / 4 hours and pressurization 170 degreeC / 15 minutes. The roll is polished to a diameter of 16 mm, divided into three times of 500 μm, two times of 250 μm, and five times with a roll grinder so that the surface roughness is extremely low, and then uniformly rotating the roll with # 5000 water-resistant paper. Surface treatment was performed so that the surface might be smooth, and the roll which has many recessed holes was obtained.

At this point, the surface roughness Rz of the roll was measured as a ten point average roughness in accordance with JIS B 0601-1994. In addition, the surface state was observed with the electron microscope to confirm the concave state. The area ratio (%) of the recessed part of the molded object surface in the whole area was calculated | required from the acquired electron micrograph. In addition, the sheet | seat of thickness 2mm was used for the measurement of hardness (durometer type A) etc. by the sheet according to JISK6249.

Further, assuming that the roll is for a developing roll using a nonmagnetic one-component toner having an average particle diameter of 8 mu m, the 8 mu m toner is sufficiently applied to the roll for the purpose of forming a uniform layer of the toner on the developing roll. As a toner peeling blade, 0.2 kg of thickness was applied to both ends of a SUS plate with a thickness of 0.2 kg to compress the roll, and after idling for 30 seconds, the toner remaining on the roll was transferred to the cellophane tape and the toner was attached to the cellophane tape. Carriability was investigated. The amount of toner adhered to the cellophane tape is 0.1 g / cm ² or more, ○, 0.05 g / cm ² or more 0.1 g / cm ² △ less than 0.05 g / cm ² Less was called x. In addition, the evaluation criteria of the light and shade of toner are as follows.

Toner adhered to the cellophane tape

(Circle): Toner adheres uniformly when seen with the naked eye, and there is no tint

(Triangle | delta): A thing with <5% (whole) stain

×: 5 to 20% (total) uneven

<Example 2>

A sheet and a roll were obtained in the same manner as in Example 1, except that instead of the pulverized calcium carbonate A described in Example 1, a pulverized aluminum hydroxide B (powder B) having an average particle diameter of 20 µm and a thin morse hardness of 3.0 was used.

<Example 3>

A sheet and a roll were obtained in the same manner as in Example 1, except that sodium chloride C (powder C) having an average particle diameter of 50 µm and a thin mortar hardness of 2.5 was used instead of the ground calcium carbonate A described in Example 1.

<Example 4>

A sheet and a roll were obtained in the same manner as in Example 1, except that instead of the pulverized calcium carbonate A described in Example 1, a hard synthetic calcium carbonate D (powder D) having an average particle diameter of 5 µm and a thin mortar hardness of 3.0 was used. .

Example 5

100 parts of dimethylpolysiloxane (polymerization degree 300) sealed at both ends with dimethylvinylsiloxy group, 1 part of aerosol 200, 40 parts of hard synthetic calcium carbonate D (powder D) having an average particle diameter of 5 µm, and a Shin Mohs hardness of 3.0, Five parts of acetylene black (Denka Black HS-100, manufactured by Denki Kagaku Kogyo Co., Ltd.) were placed in a planetary mixer, followed by stirring for 30 minutes, and then passed through a triaxial roll once. This was returned to the planetary mixer, 2.1 parts of methylhydrogenpolysiloxane (polymerization degree 17, Si-H content of 0.0060 mol / g) having Si—H groups at both ends and side chains as a crosslinking agent, 0.1 part of ethynylcyclohexanol as a reaction control agent, 0.1 part of platinum catalyst (Pt concentration 1 mass%) was added, stirring was continued for 15 minutes, and the completed composition was used as the silicone rubber composition (1). In addition, the viscosity at 25 degrees C of this composition (1) was 78 Pa.s.

The silicone rubber composition (1) was pressure-cured at 150 ° C. for 5 minutes within 30 minutes after completion of stirring, and further cured after 4 hours at 200 ° C. to obtain a roll and a sheet having a thickness of 2 mm in the same manner as in Example 1.

<Example 6>

A sheet and a roll were obtained in the same manner as in Example 1, except that 40 parts of the ground calcium carbonate A described in Example 1 was reduced to 5 parts.

<Example 7>

A sheet and a roll were obtained in the same manner as in Example 1 except that 40 parts of the ground calcium carbonate A described in Example 1 were reduced to 20 parts.

<Example 8>

A sheet and a roll were obtained in the same manner as in Example 1, except that 40 parts of the ground calcium carbonate A described in Example 1 was increased to 100 parts.

Comparative Example 1

A sheet and a roll were obtained in the same manner as in Example 1, except that 10 parts of aerosil 200 were added for the purpose of adjusting the rubber hardness instead of adding the pulverized calcium carbonate A described in Example 1.

Comparative Example 2

A sheet and a roll were obtained in the same manner as in Example 5, except that 10 parts of aerosil 200 were added for the purpose of adjusting the rubber hardness instead of adding the hard synthetic calcium carbonate D described in Example 5.

Comparative Example 3

Instead of the pulverized heavy calcium carbonate A described in Example 1, Example 1 except that it was changed to calcined diatomaceous earth off-lite W3005S (powder E) (offlite high school manufactured) having an average particle diameter of 5.4 µm and a new MOS hardness of 5.5. Similarly, sheets and rolls were obtained.

<Comparative Example 4>

Instead of the pulverized heavy calcium carbonate A described in Example 1, Crystallite VX-S (Powder F) (trade name, manufactured by Tatsumori Co., Ltd.) having an average particle diameter of 4 µm and coarse particles of 20 µm or more was about 1% or less was used. A sheet and a roll were obtained in the same manner as in Example 1 except that the resultant was changed to one.

Comparative Example 5

Instead of the pulverized heavy calcium carbonate A described in Example 1, Crystallite A-2 (Powder G) (trade name, manufactured by Tatsumori Co., Ltd.) having an average particle diameter of 28 μm and a coarse particle of 140 μm or more is about 4% or more is used. A sheet and a roll were obtained in the same manner as in Example 1 except that the resultant was changed to one.

Comparative Example 6

Alumina AS-50 (powder H) which is aluminum oxide whose average particle diameter is 10 micrometers and 50 micrometers or more of coarse particle | grains are about 3% or more instead of the pulverized heavy calcium carbonate A of Example 1 (made by Tatsumori Corporation, brand name) The sheet and the roll were obtained similarly to Example 1 except having changed to using.

Comparative Example 7

KMP-598 (Powder I) (Shin-Etsu Chemical Co., Ltd.), which is a silicone rubber powder having an average particle diameter of 13 μm and a coarse particle of 65 μm or more, instead of 40 parts of the ground heavy calcium carbonate A described in Example 1 Note) A sheet and a roll were obtained in the same manner as in Example 1, except that 20 parts of production) were changed to those used.

The results of the Examples and Comparative Examples are shown in Tables 1 and 2 below. In addition, the characteristic of the filler used by the Example and the comparative example was put together in Table 3, and is shown.

* 1: ratio of the coarse particles having a particle size of 5 times or more to the average particle diameter of the filler

* 2: 10-point average roughness according to JIS B 0601-1994

* 3: [(area of the part where the molding surface is concave) / (area of the entire surface)] × 100 (%)

It was found that a filler having a large proportion of coarse particles having a particle size of five times or more relative to the average particle diameter of the filler is likely to cause light toner.

According to the present invention, an electrophotographic image forming for which a plurality of concave holes are provided on a rubber surface by grinding or surface wear of a cured silicone rubber surface or by surface friction in an environment of use, whereby the blended filler is crushed or dropped. A rubber member can be provided, and when the rubber member is used for a developing roll, the surface roughness becomes rough and an increase in the physical conveyance force of the toner can be expected, and when used for the toner blade, the rubber member or other resin can be scratched. It is possible to have a stable peeling ability without. In addition, the rubber members, rolls, belts, etc., which have a possibility of wear on the surface, have a small change in the surface state even if they are used continuously, and can maintain their initial characteristics and withstand long-term use. Is particularly useful for office equipment members such as developing rolls, toner conveying rolls, paper feed rolls, intermediate transfer rolls, fixing rolls, toner blades, developing belts, intermediate transfer belts and fixing belts.

Claims (7)

(A) organopolysiloxane represented by the following general formula (1): 100 parts by mass, (B) a filler having an average particle diameter of 2 to 200 µm having a new Morse hardness of 5.0 or less: 5 to 200 parts by mass, and (C) Curing agent: Curing effective amount And a silicone rubber obtained by curing a silicone rubber composition containing a silicone rubber composition, wherein the rubber surface is subjected to polishing or surface abrasion or surface friction in an environment of use so that the filler, which is the component (B), is pulverized or dropped. Rz ratio of the surface roughness (X) of the silicone rubber obtained by hardening the composition from which the (B) component was removed from the surface roughness (X) and the silicone rubber composition after the recessed hole of the said silicone rubber was formed ( X / Y) is 1.2 or more, The rubber member for electrophotographic image forming which has many recessed holes in the surface. <Formula 1> R _n SiO _{(4-n) / 2} In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group, n is a positive number of 1.95 to 2.05. The rubber member for electrophotographic image forming according to claim 1, wherein the total area of the concave hole portions of the rubber surface is 15% or more of the entire rubber surface area when measured from an electron micrograph. The particle size distribution according to claim 1 or 2, wherein the component (B) has a particle size distribution adjusted so that the proportion of the filler having a particle size of 5 times or more to the average particle diameter of the filler measured by laser diffraction scattering is 2.3 mass% or less. It is a filler, The rubber member for electrophotographic image forming. The rubber member for electrophotographic image forming according to claim 1 or 2, wherein the filler is calcium carbonate, sodium chloride or aluminum hydroxide, and has an average particle diameter of 2 to 70 m. The rubber member for electrophotographic image forming according to claim 1 or 2, wherein the silicone rubber composition is a rubber material to which conductivity is imparted, further comprising (D) a conductive material. The rubber member for electrophotographic image forming according to claim 1 or 2, which is for a toner blade, a developing roll, a toner conveying roll, a paper conveying roll, an intermediate transfer roll, a fixing roll, a developing belt, an intermediate transfer belt, or a fixing belt. An electrophotographic image forming apparatus comprising the rubber member for electrophotographic image forming according to claim 6.