JP2003307895A - Ion conductive foaming silicone rubber composition, ion conductive foaming silicone rubber, ion conductive foaming silicone rubber roll and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion conductive foaming silicone rubber composition which suppresses and prevents contamination of a photoreceptor or the like and responds to high picture quality and to provide an ion conductive foaming silicone rubber, an ion conductive foaming silicone rubber roll and an image forming device. <P>SOLUTION: The composition is obtained by compounding 0.1 to 20.0 parts by mass of an ion conductive composition, 0.1 to 20.0 parts by mass of an aluminate coupling agent or 0.1 to 20.0 parts by mass of a titanate coupling agent, a necessary amount of a foaming agent, and a necessary amount of a vulcanizing agent in 100.0 parts by mass of a silicone rubber compound. By adding the aluminate or titanate coupling agent, bleeding of polymers having unshared electron pairs in thermal motion can be decreased. Thus, the composition suppresses and prevents an adverse effect on a printed image and responds to high picture quality of an image. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing roll, a charging roll, a toner transporting roll, a transfer roll, a photosensitive drum cleaning roll, or an ion beam for an OA device including a laser beam printer or a copying machine provided with these. The present invention relates to a conductive foamable silicone rubber composition, an ion conductive foamable silicone rubber, an ion conductive foamable silicone rubber roll, and an image forming apparatus.

[0002]

2. Description of the Related Art Although not shown, an image forming apparatus used in an electrophotographic copying machine or a laser beam printer obtains a printed matter by repeating charging, exposing, developing, transferring, cleaning and fixing steps. In these steps,
Charging rolls, toner transport rolls, developing rolls, photosensitive drum cleaning rolls, and transfer rolls are used, and these are printed by changing the applied voltage or current when the printing conditions, paper type, environment, etc. change. It functions to maintain a constant quality. Each of the rolls is a semi-conductive roll and is formed into a foamed structure using urethane rubber, NBR, EPDM, or silicone rubber.
Particularly, for the toner transport roll, the photosensitive drum cleaning roll, and the transfer roll, a semiconductive roll made of foamable rubber is used.

[0003]

As a method of making the above materials semi-conductive, an electron conductive method using a carbon-based conductive material as a main material is generally used. However, in the case of such a method, there is a limit in maintaining the stability of carbon, which is a conductive material, in an environment under a high voltage used in a laser beam printer or the like. There is a problem that the structure becomes disconnected and the resistance value deviates from the set value. This problem,
The higher the voltage becomes, and the more current is passed, the more obvious it becomes.

Further, it is known that when ordinary conductive carbon black is used, the tunnel effect due to the carbon structure causes the relationship between current and voltage to be non-linear, not according to Ohm's law. Such non-linearity of current and voltage is unreasonable as the characteristics of rolls around the photosensitive drum, such as highly accurate developing rolls and transfer rolls, so the method of making them conductive by ion conduction has been adopted recently. Has been done. The ionic conductivity as referred to herein means that a non-shared electron pair in a polymer that can freely move thermally and a metal ion such as lithium exchange electrons to become conductive.

In such a method, although the resistance value has little voltage dependency, it is necessary to add a polymer having a non-shared electron pair that thermally moves in order to make the material ionic conductive. It's polluted,
There is a problem that the image of the printed matter is adversely affected. As described above, it has been extremely difficult for the conventional ion conductive foamable roll to cope with the recent high image quality.

The present invention has been made in view of the above, and is an ion conductive foamable silicone rubber composition, an ion conductive foamable silicone rubber, which can prevent contamination of a photoreceptor or the like and can cope with high image quality. An object of the present invention is to provide an ionic conductive foamable silicone rubber roll and an image forming apparatus.

[0007]

The present inventor reduces the bleeding of a polymer having a non-covalent electron pair that thermally moves by adding an aluminate-based coupling agent or a titanate-based coupling agent to the composition. The inventors have found out what can be done and have completed the present invention. That is, in the invention according to claim 1, in order to achieve the above object, 0.1 to 20.0 parts by mass of the ion conductive composition and an aluminate coupling are used with respect to 100.0 parts by mass of the silicone rubber compound. 0.1 to 20.0 parts by mass of the agent or 0.1 to 20.0 parts by mass of a titanate coupling agent, a necessary amount of a foaming agent, and a necessary amount of a vulcanizing agent.

In order to achieve the above object, the invention according to claim 2 is characterized in that the ionic conductive foamable silicone rubber composition according to claim 1 is formed by foaming and curing. In order to achieve the above object, the invention according to claim 3 is characterized in that the ionic conductive foamable silicone rubber composition according to claim 1 is foamed and cured. Further, in order to achieve the above object, in the invention according to claim 4, an image forming roll is rotatably provided in the housing, and the roll is the ion conductive foamable silicone according to claim 1. It is characterized in that the rubber composition is an ionic conductive foamable silicone rubber roll which is foamed and cured.

The present invention will be described in detail below. The rubber composition according to the present invention comprises a silicone rubber compound 10
A foam with 0.0 part by mass is particularly preferable. The ion conductive foamable silicone rubber composition has a vinyl group-containing organopolysiloxane as a main component, a hydrogen polysiloxane as a cross-linking agent, and is further vulcanized. It contains an auxiliary agent, a reaction inhibitor, a physical property auxiliary agent, a platinum compound catalyst, an ion conductive composition, a foaming agent, a vulcanizing agent and the like.

The silicone rubber compound is a vinyl group-containing dimethyl silicone raw rubber, a vinyl group-containing phenyl silicone raw rubber, a vinyl group-containing fluorosilicone raw rubber, or a modified product thereof, such as an organopolysiloxane, and if necessary, fumed silica or It is formed by adding a reinforcing silica filler such as precipitated silica.

Organic peroxides are mainly used as vulcanization aids. If a peroxide is used together as the vulcanization aid, the physical properties can be expected to be improved. This includes benzoyl peroxide, bis 2,4 dichlorobenzoyl peroxide, dicumyl peroxide and di-t-butyl peroxide. Oxide, 2,5-dimethyl-2,5-bis (t-
Butyl peroxy) hexane etc. are applicable. Further, in order to adjust the heat resistance improver and hardness, non-reinforcing silica may be added, and the plasticity of the silicone rubber compound is adjusted by adjusting the addition amount of reinforcing silica or non-reinforcing silica. can do.

Examples of the reaction inhibitor include methylvinylcyclotetrasiloxane, acetylene alcohols, siloxane-modified acetylene alcohol and hydroperoxide. In addition, examples of the physical property auxiliary agent include non-reinforcing silica for adjusting hardness and improving heat resistance. Also,
The platinum compound catalyst functions as a curing accelerator for addition reaction. The platinum-based compound catalyst is not particularly limited, for example, chloroplatinic acid, alcohol-modified chloroplatinic acid, platinum supported on a solid catalyst such as platinum black, alumina, silica, carbon, platinum and olefin. , Ethylene, alcohol, vinyl siloxane, etc., chloroplatinic acid and olefin, ethylene, alcohol, vinyl siloxane, etc.

The ionic conductive substance of the ionic conductive composition that imparts conductivity may be a cationic substance, such as H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Ag ⁺ , Zn ₂ ⁺ . Any electrolyte having a cationic property may be used. As the inorganic electrolyte, LiBF ₄ , LiAlCl ₄ , NaBr, NaI,
KI, AgNO _{3 and the} like are listed, and as the organic electrolyte,
Examples thereof include primary, secondary and tertiary amine salts, quaternary ammonium salts and quaternary phosphonium salts.

The solvent for dissolving these is not limited to a low molecular weight substance, as long as the electrolyte can be dissolved, and a solvent for a high molecular weight substance may be used. Examples of the solvent for the high molecular weight substance include polyethers such as polyethylene oxide and polypropylene oxide, polyesters such as polyethylene succinate, and polyimines such as polyethyleneimine.

In the present invention, 0.1 to 20.0 parts by mass of a 10.0 wt% solution of an ion conductive composition in which LiClO ₄ (lithium perchlorate) as an ion conductive substance is dissolved in polyether. Added. This is because if the amount is less than 0.1 part by mass, the required amount of conductivity cannot be imparted to the silicone rubber compound. vice versa,
If it exceeds 20.0 parts by mass, the problem of conductivity does not occur, but the plasticity of the silicone rubber compound decreases,
This is because it cannot be formed into a roll.

The foaming agent is a chemical foaming agent whose decomposition temperature is close to the vulcanization temperature of silicone rubber and is easy to control.
1'-azobisisobutyronitrile (hereinafter abbreviated as AIBN) is preferably used. This chemical foaming agent generally has a decomposition temperature of 100 to 200 ° C. and is characterized in that it is easily balanced with the vulcanization method of the present invention when foaming simultaneously with heat vulcanization. The content of the chemical foaming agent may be an appropriate and necessary amount, but is preferably in the range of 0.1 to 30.0 parts by mass with respect to the silicone rubber compound before vulcanization. If this is less than 0.1 part by mass,
This is because if the foaming does not occur sufficiently and, conversely, if it exceeds 30.0 parts by mass, the foamed elastic body cannot retain its shape and the mechanical strength may decrease.

Further, as the vulcanizing agent, organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule is used. The required amount of the vulcanizing agent is 0.5 part by mass or more. This is because when the vulcanizing agent is less than 0.5 parts by mass, unreacted portions remain in the physical properties of the silicone rubber during vulcanization, and the general physical properties of the silicone rubber are not achieved.

In these formulations, a conductive metal oxide may be added to stabilize the semiconductive region and form uniform foam pores. Examples of such conductive metal oxides include conductive aluminum oxide, conductive titanium oxide, and conductive zinc oxide. Among these, particularly conductive zinc oxide improves the stability of the electric resistance value in the semi-conductive region, and can be expected to have a small time lag in heat conduction in the rubber composition when the foaming agent is decomposed. And the effect of obtaining a foam having uniform pores is enhanced.

In the present invention, spherical particles may be added for the purpose of reinforcing general physical properties and forming uniform foam pores. Examples of the spherical particles include silicone rubber balls and glass beads, but elastic silicone rubber balls that do not damage contact objects are preferable. Further, an inorganic filler such as crystallite may be added for adjusting the charge amount as long as the adverse effect is not caused.

Furthermore, an aluminate-based coupling agent or a titanate-based coupling agent is added to the ion conductive foamable silicone rubber composition according to the present invention. Aluminate coupling agent is

[Chemical 1] And the like.

The titanate coupling agent is

[Chemical 2] And the like. The addition amount of these aluminate-based coupling agent or titanate-based coupling agent depends on the plasticity of the silicone rubber composition in the initial stage and the addition amount of a liquid additive such as a dispersant.
A range of 20.0 parts by mass is preferred. This is because when the addition amount of the aluminate-based coupling agent or the titanate-based coupling agent is less than 0.1 parts by mass, the effect of reducing the bleeding of the polymer cannot be expected, and conversely 20
This is because if the amount is more than parts by mass, the plasticity of the silicone rubber compound becomes too high, and it cannot be formed into a roll.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of the present invention will be described below with reference to the drawings. An ion conductive foamable silicone rubber roll and an image forming apparatus according to the present embodiment are as shown in FIGS. The ionic conductive foamable silicone rubber composition is foamed and cured to form an ionic conductive foamable silicone rubber roll 1, and the ionic conductive foamable silicone rubber roll 1 is placed in a housing 11 of an image forming apparatus 10 including a laser beam printer. A rotatable charging roll 12, a toner transporting roll 15, a developing roll 16, a photosensitive drum cleaning roll 18, and / or a transfer roll 17, which are rotatably supported by the above, are used.

Ion conductive foamable silicone rubber roll 1
As shown in FIG. 1 and FIG. 2, is formed into a columnar shape having elasticity, and is penetrated and supported by a conductive rotating shaft 2 made of stainless steel or the like. Further, the image forming apparatus 10 prints a printed matter by attaching toner to an electrostatically formed image, transferring the toner to the paper P and thermally fixing the toner. Specifically, as shown in FIG. 3, the image forming apparatus 10 charges, exposes, develops, transfers, cleans,
The printed matter is printed by repeating the fixing process.

These steps will be described in order. First, in the charging step, the photosensitive drum 13 is exposed to corona discharge by the charging roll 12 to be charged, and the surface of the photosensitive drum 13 is uniformly charged and exposed. In the process, the LED array head 14 illuminates the original,
The reflected light is projected as a bright and dark image on the photosensitive drum 13 by an optical system such as a lens and a mirror to form an electrostatic latent image.

In the developing step, the toner conveyed from the toner cartridge by the toner conveying roller 15 is used to visualize the electrostatic latent image on the developing roller 16, and in the transferring step, the visualized image is transferred by the transfer roller 17. It is electrostatically transferred onto a sheet (for example, A4 copy sheet) P. Further, in the cleaning process, the toner remaining on the surface of the photosensitive drum 13 that has been used once is wiped by the photosensitive drum cleaning roll 18, and in the fixing process, the toner is heated and pressure-fixed on the paper P.

According to the above constitution, since the aluminate-based coupling agent or the titanate-based coupling agent is added to the composition of the ionic conductive foamable silicone rubber roll 1, the polymer having a non-covalent electron pair that thermally moves is used. Bleed can be reduced. Therefore, not only can the image be stabilized for a long period of time, but also it is possible to prevent the image of the printed matter from being adversely affected, and it is possible to very easily cope with the recent high image quality.

[0027]

EXAMPLES Examples of the ion conductive foamable silicone rubber roll and the image forming apparatus according to the present invention will be described below together with comparative examples. Example 1 First, with respect to 100.0 parts by mass of a silicone rubber compound [trade name KE-151U manufactured by Shin-Etsu Chemical Co., Ltd.], a 10.0 wt% solution of LiClO ₄ (lithium perchlorate) dissolved in polyether 5.0 parts by mass of an ion-conductive composition, 5.0 parts by mass of an aluminate-based coupling agent [Plainact AL-M manufactured by Ajinomoto Co., Inc.], 20.0 parts by mass of conductive zinc oxide, and organic peroxide. Vulcanizing agent [Shin-Etsu Chemical Co., Ltd., trade name C-3] 2.0
Blowing agent consisting of parts by mass and AIBN [same brand name KEP-1
3] 3.0 parts by mass, 3.0 parts by mass of a vulcanizing agent consisting of organohydrogenpolysiloxane [trade name C-153A manufactured by Shin-Etsu Chemical Co., Ltd.], chloroplatinic acid as a catalyst, and a reaction inhibitor are added in appropriate amounts. An ionic conductive foamable silicone rubber formulation was prepared.

Then, the conductive rotary shaft was washed with toluene and treated with a primer. As the axis of rotation, φ8 x 250
A shaft body in which electroless nickel plating was applied to SUS22 having a size of mm was used. The primer treatment is a treatment for adhering the ion conductive foamable silicone rubber compound and the rotating shaft. As a specific primer treatment, a rotating shaft coated with alkoxysilane as a main component was baked in a gear oven at a temperature of 150 ° C. for 30 minutes. When the rotating shaft is treated with a primer in this way,
What was cooled for more than an hour was dispensed together with the ion conductive foamable silicone rubber compound by an extruder and IR
A baking treatment was performed in a furnace at a temperature of 360 ° C. for 6 minutes to form an intermediate of an ionic conductive foamable silicone rubber roll.

Then, the intermediate body of the ionic conductive foamable silicone rubber roll is fired in a gear oven at a temperature of 200 ° C. for 6 hours and left at room temperature for 1 hour or more, and then,
Ion conductive foamable silicone rubber rolls were produced by grinding to φ16 mm with a cylindrical grinder. After the ion conductive foamable silicone rubber roll was prepared in this way, it was set in the printing tester shown in FIG. 3 and a printing test was carried out, and the results are summarized in Table 1.

Example 2 The same procedure as in Example 1 was carried out except that the amount of the aluminate-based coupling agent [Plainact AL-M manufactured by Ajinomoto Co., Inc.] added was 20.0 parts by mass. Example 3 The same procedure as in Example 1 was performed except that the addition amount of the same aluminate coupling agent as described above was 0.1 part by mass. Example 4 The same procedure as in Example 1 was carried out except that 5.0 parts by mass of a titanate coupling agent [trade name Plane Act KR-44 manufactured by Ajinomoto Co., Inc.] was added in place of the aluminate coupling agent.

Comparative Example 1 Aluminate coupling agent was not added,
The other conditions were the same as in Example 1. Comparative Example 2 The same amount of aluminate-based coupling agent as above was added in an amount of 22.0 parts by mass, and otherwise the same as in Example 1. Comparative Example 3 The same as Example 1 except that the ion conductive composition was not added.

Printing Test Each roll produced in the examples and comparative examples was set as a transfer roll in a laser beam type printing tester, and black solid printing was performed. Then, take out the 1000th printed matter and visually confirm whether the print is faint or not,
The results are summarized in Table 1 by symbols of ⊚, ○, Δ, and ×.

[0033]

[Table 1]

[0034]

As described above, according to the present invention, there is an effect that it is possible to suppress or prevent the contamination of the photoconductor or the like and cope with the high image quality.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of an ion conductive foamable silicone rubber roll according to the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a schematic cross-sectional explanatory view showing an embodiment of an image forming apparatus according to the present invention.

[Explanation of symbols]

1 Ion conductive foaming silicone rubber roll 10 image forming apparatus 11 housing 12 charging roll 13 Photosensitive drum 15 Toner transport roll 16 developing roll 17 Transfer roll 18 Photosensitive drum cleaning roll

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/08 501 501 G03G 15/08 501A 4F074 501D 15/16 103 15/16 103 21/10 C08L 83:04 // C08L 83:04 G03G 21/00 312 F-term (reference) 2H077 AC04 AD06 FA00 FA13 FA16 FA22 FA25 2H134 GA01 GB02 HA01 HA03 HA17 KD02 KD07 KD11 KD12 KG01 KG03 KG04 KG07 KG08 KH01 2H171 FA11 FA13 FA15 FA17 FA26 GA01 GA25 QB03 QB35 QC03 QC23 UA03 UA07 UA08 UA10 UA22 XA02 2H200 FA02 FA08 FA17 GB15 HA03 HA28 HB12 HB22 HB45 HB46 HB47 JA02 JA25 JA26 JA27 LC09 MA01 MA03 MA08 MA13 MA17 MA20 MB01 MB02 MC01 MC03 3J103 AA02 AA13 AA21 AA32 BA41 BA46 EA02 EA11 FA06 FA07 FA14 FA18 GA02 GA52 GA57 GA58 GA64 GA66 GA73 GA74 HA03 HA05 HA12 HA15 HA18 HA20 HA53 4F074 AA90 AC22 AD04 AG08 BA14 BB 01 CA21 CC04Y CC06Y DA17 DA47

Claims (4)

[Claims] 1. Silicone rubber compound 100.0
Ion conductive composition 0.1 to 20.0 with respect to parts by mass.
Parts by mass, aluminate coupling agent 0.1-20.
0 parts by mass or titanate coupling agent 0.1-2
An ion conductive foamable silicone rubber composition comprising 0.0 parts by mass, a required amount of a foaming agent, and a required amount of a vulcanizing agent. 2. An ion conductive foamable silicone rubber, which is formed by foaming and curing the ion conductive foamable silicone rubber composition according to claim 1. 3. An ion conductive foamable silicone rubber roll, which is formed by foaming and curing the ion conductive foamable silicone rubber composition according to claim 1. 4. An image forming apparatus in which a roll for image formation is rotatably provided in a housing, wherein the roll is formed by ion-foaming the ion-conductive foaming silicone rubber composition according to claim 1. An image forming apparatus using a silicone rubber roll.