JPH03100057A - Silicone rubber composition, and molding, elastic rotating body and fixing apparatus formed from same composition - Google Patents

Abstract

PURPOSE:To obtain a silicone rubber composition improved in mechanical strengths, resiliency, antistatic effect and antistatic effect by mixing a silicone rubber with a specified porous inorganic fine powder and a surface-modified synthetic fine silicic powder. CONSTITUTION:100 pts.wt. microporous fine powder of a particle diameter of 1-70mum, a mean particle diameter of 1-40mum and an oil absorption of 200-800ml/100g is impregnated with a silicone polyether having a polyoxyalkylene group as a side chain. Separately, a synthetic silicic acid of a primary particle diameter of 7-100mmu, and a specific surface area of 40-500m<2>/g is surface-treated with an alkyl-silane compound and/or dimethylsilicone and a silane compound having an unsaturated group reactive with an addition reaction-type silicone rubber. A silicone rubber whose main chain is composed of an organopolysiloxane of the formula (wherein R1-2 are each an alkyl, an aryl or a polyfluoroalkyl, and (m) is a positive integer) is mixed with the impregnated powder and surface-treated silicic acid prepared above.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a silicone rubber composition having a specific composition, a molded article formed from the composition, and an elastic article having a surface layer formed from the silicone rubber composition. The present invention relates to an elastic rotating body including a body and a fixing device having the elastic rotating body.

[Conventional technology]

2. Description of the Related Art In image forming apparatuses such as electronic copying machines, a conveyance roller that conveys a sheet-like transfer material or recording material such as plain paper along a predetermined path is generally required to have good conveyance performance, releasability, and durability.

In particular, fixing rollers and heat rollers that must apply heat under pressure to the unfixed toner image on the transfer paper and convey the transfer paper to a predetermined path while preventing the offset phenomenon of semi-melted or molten toner. A fixing device equipped with a pressure roller is required to have conveyance properties, release properties, abrasion resistance, fixing properties, and durability under more severe conditions.

Conventionally, this type of fixing device has a fixing roller and a pressure roller that is in pressure contact with the fixing roller and rotates drivenly. The fixing roller is made of aluminum, for example.

Polytetrafluoroethylene is placed on a hollow core made of iron, etc.
A layer of a material with good mold releasability such as a fluororesin such as a tetrafluoroethylene-fluoroalkoxyethylene copolymer or a silicone rubber is formed as a coating. Also,
The fixing roller is provided with a heater such as a halogen lamp, if necessary, to raise the temperature of the surface of the fixing roller to a specific temperature suitable for fixing. In addition, in the case of multiplexing, the surface temperature of the fixing roller is controlled using a sensor so that it always remains at a set temperature.Furthermore,
The outer peripheral surface of the fixing roller may be provided with a cleaner for removing offset toner and paper dust, and a separation claw for preventing the image bearing material from being wrapped around the fixing roller.

On the other hand, in the pressure roller, a core metal such as iron or stainless steel is coated with an elastic layer having release properties such as silicone rubber. The pressure roller is pressed against the fixing roller by a spring or the like.

(Thus, the image bearing material having the unfixed toner image is conveyed while being held under heat and pressure by the fixing roller and the pressure roller, so that the unfixed toner image is fixed under heat and pressure.

[Problem to be solved by the invention]

However, in the above-mentioned conventional apparatus, there is a problem in that the pressure roller becomes charged to, for example, 2 KV or more due to frictional electrification when paper is passed through the paper, and as a result, the paper wraps around the pressure roller. In addition, due to the electric field of the pressure roller, unfixed toner scatters and blurs the line image, and the toner adheres to the surface of the fixing roller, causing many offsets.

As a countermeasure to the above-mentioned problem, conventionally, a static elimination brush was brought into contact with the pressure roller to eliminate static electricity by grounding. However, even with this measure, the electric potential drops to only about 1 to 2 KV, which limits the static elimination effect and is not sufficient, and an improvement has been desired.

In addition, in the case of a fixing device that does not have a cleaning means for cleaning the surface of the fixing roller, if the surface of the pressure roller is highly charged, the amount of toner adhering to the surface of the fixing roller increases, and the toner is transferred to a transfer material such as paper. Alternatively, since the toner is transferred to the pressure roller surface, problems such as image defects such as offset and toner adhesion stains on the roller surface are likely to occur.

To solve these problems, there is a method in which a porous inorganic fine powder having micropores carrying a silicone polyether copolymer having a polyoxyalkylene group in the side chain is added to a liquid addition reaction type silicone rubber.

However, there were problems with the reinforcing properties of silicone rubber. Generally, a method of reinforcing silicone rubber is to add synthetic silicic acid (commonly known as white carbon) such as hydrous synthetic silicic acid or anhydrous synthetic silicic acid. The reinforcing effect cannot be achieved unless it is used in a considerably large amount (parts by weight), and there is also the problem that mold releasability is significantly reduced when a large amount is added.

In the case of anhydrous synthetic silicic acid, a reinforcing effect can be achieved when added in a smaller amount, for example, 10 to 20 parts by weight, compared to hydrous synthetic silicic acid, but there is still a problem in that the releasability is significantly reduced.

Therefore, in either case, fixing properties and mold release properties were not reduced (mechanical strength could not be significantly improved).

The present invention relates to silicone rubber obtained by treating the surface of synthetic silicic acid such as anhydrous synthetic silicic acid and hydrous synthetic silicic acid with at least one of alkylsilane and dimethyl silicone oil and an unsaturated group-containing silane compound. A surface-modified synthetic silicic acid containing a reactive functional group and a porous inorganic fine powder having micropores supporting a silicone polyether copolymer having a polyoxyalkylene group in the side chain are mixed into a silicone rubber. The above problem was solved by adding and mixing.

[Purpose of the invention]

The present invention provides a silicone rubber composition that has excellent mechanical strength and high impact resilience.

An object of the present invention is to provide a silicone rubber composition with excellent antistatic effect.

An object of the present invention is to provide a silicone rubber composition with excellent static elimination effect.

An object of the present invention is to provide an elastic rotating body that has excellent mechanical strength and high rebound resilience.

An object of the present invention is to provide an elastic rotating body with excellent antistatic effect.

An object of the present invention is to provide an elastic rotating body with excellent static elimination effect.

An object of the present invention is to provide an elastic rotating body whose surface is less likely to be contaminated.

An object of the present invention is to provide an elastic rotating body with excellent durability.

An object of the present invention is to provide a fixing device with excellent offset resistance.

An object of the present invention is to provide a fixing device with excellent durability.

[Summary of the invention]

Specifically, the present invention includes a silicone rubber, a porous inorganic fine powder having micropores supporting a silicone polyether copolymer having a polyoxyalkylene group in a side chain, an alkylane compound, dimethyl silicone oil, or the like. The present invention relates to a silicone rubber composition comprising a mixture of the above and a synthetic silicic acid fine powder whose surface has been modified with a silane compound containing an unsaturated group that is reactive with addition-reactive silicone rubber.

Furthermore, the present invention relates to a molded article, an elastic rotating body, and a fixing device formed from the silicone rubber composition.

The present invention provides at least one of (a) a porous inorganic fine powder having micropores supporting a silicone polyether copolymer having a polyoxyalkylene group in the side chain, and (b) an alkylsilane compound and dimethyl silicone oil. A silicone rubber composition contains synthetic silicic acid whose surface has been modified with one and a silane compound containing a functional group that is reactive with silicone rubber.

The silicone rubber composition of the present invention may be either an addition reaction type or a radical reaction type.

In addition, R1'+R2 is an alkyl group such as a methyl group or an ethyl group, an aryl group such as a phenyl group, a polyfluoroalkyl group such as a trifluoropropyl group, etc., which constitute the silicone rubber composition of the present invention. It is.

The silicone polyether copolymer having a polyoxyalkylene group in the side chain in the present invention has a nonionic surfactant structure in which the dimethylpolysiloxane part of the molecule is a hydrophobic group and the polyether part is a hydrophilic group. For example, it has the following.

As the porous fine powder having micropores in the present invention, an inorganic fine powder is preferable from the viewpoint of thermal stability, and the silicone polyether copolymer having a polyoxyalkylene group used in the present invention is supported in a large amount. It is preferable to use a material with a large amount of oil absorption. For example, gyrolite type calcium silicate (e.g. Fluorite manufactured by Tokuyama Soda), spherical porous silica (e.g. M, S, GEL manufactured by Dokai Chemical Industry Co., Ltd.)
, silica microbeads manufactured by Catalysts & Chemicals Co., Ltd., siloids manufactured by Fuji Davison Chemical Co., Ltd.), and Shirasu balloons. The fine powder has a particle size in the range of 1 to 70 μm, an average particle size in the range of 1 μm to 40 μm, and an oil absorption of 200 to 800 mf/100 g, preferably 300 to 600 m! ! /100g is suitable.

The impregnation ratio of the silicone polyether copolymer having a polyoxyalkylene group to the fine powder is as follows:
00 parts by weight is preferably 100 to 600 parts by weight,
In particular, a range of 200 to 500 parts by weight is preferred. The amount of the porous fine powder having micropores supporting the silicone polyether copolymer added to the silicone rubber composition is 0.1 to 20% by weight based on the actual amount of silicone polyether copolymer added based on the silicone rubber. %, preferably 1
．． Amounts corresponding to 5 to 10% by weight are suitable. Addition amount is 0.
If the amount is less than 5% by weight, the antistatic effect will not be exhibited, and if the amount is more than 20 parts by weight, the physical properties will deteriorate.

Synthetic silicic acid whose surface has been modified with at least one of an alkylsilane compound and dimethyl silicone oil and a silane compound containing a functional group that is reactive with silicone rubber in the present invention will be described.

Examples of the alkylsilane compounds used in the present invention include trimethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyljethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, and methyltrichlorosilane. , Dimethyl silicone oil has the following formula: The silane compound containing a functional group reactive with silicone rubber used in the present invention is one in which the functional group is an unsaturated group such as a vinyl group, allyl group, propenyl group, etc. This is an example.

For example, vinyltriethoxysilane, dimethylvinylmethoxysilane, dimethylvinylethoxysilane, methylvinyldimethoxysilane, methylvinyljethoxysilane, vinyltrichlorosilane, dimethylvinylchlorosilane, methylvinyldichlorosilane, γ-methacryloxypropyltrimethoxysilane, An example is γ-methacryloxypropyldimethoxysilane.

The synthetic silicic acid used in the present invention is a white ultrafine powder of silicic anhydride (SiO2.
nH20, SiO2 is 95% or more), hydrated silicic acid (Si
O26nH20, SiO2 is 80-95%), hydrated calcium silicate (x-8iO2・CaO・yH20, Si
O2 55-70%), hydrated silicic acid 7/l/l/miniram@5i02 ・A1203 *yH20,5i02
is 60 to 70%), has a secondary particle diameter of 7 to 100 mμ, and a specific surface area of 40 to 500 rrr/g.
It is within the range of . The surface modification of the synthetic silicic acid with the above-mentioned treatment agent is carried out by a known treatment method.

The silicone rubber composition of the present invention may contain finely powdered synthetic silica, crushed quartz powder, fused quartz powder, diatomaceous earth, calcium carbonate, etc. as a filler, and iron oxide as an additive, within a range that does not impair the purpose of the present invention. A heat resistance improver such as, a compression set improver such as titanium oxide or zinc oxide, a dispersant such as a low molecular weight siloxane, etc. may be used.

The addition reaction type silicone rubber composition of the present invention comprises (I)1
100 parts by weight of an organopolysiloxane having a small number (both of which have two silicon-bonded unsaturated groups) in the molecule.

(■) Organohydrodiene polysiloxane having at least three silicon-bonded hydrogen atoms in one molecule.

(m) A porous inorganic fine powder having micropores supporting a silicone polyether copolymer having a polyoxyalkylene group in its side chain.

(IV) Synthetic silicic acid whose surface has been modified with an alkylsilane compound, a small amount of dimethyl silicone oil (one of them, and a silane compound containing an unsaturated group).

(V) Platinum compound 0.1 to 5 based on the total amount of component (1) and CTI)
Consisting of 00 ppm.

Component (I), organopolysiloxane, is the main component of the composition of the present invention, and is cured by addition reaction with component (n), which is a crosslinking agent, due to the catalytic action of component (m). The unsaturated groups of the synthetic silicic acid whose surface has been modified with the unsaturated group-containing silane compound of component (rV) are also modified by the catalytic action of component (m).
I) Addition reaction with component. (1) As the organopolysiloxane component, methylvinylpolysiloxane, a copolymer of methylvinylsiloxane and dimethylsiloxane,
Dimethylpolysiloxane with dimethylvinylsiloxy groups blocked on both ends, dimethylsiloxane-methylphenylsiloxane copolymer with dimethylvinylsiloxy groups blocked on both ends, dimethylsiloxane-diphenylsiloxane-methylvinylsiloxane copolymer with dimethylvinylsiloxy groups blocked on both ends Dimethylsiloxane-methylvinylsiloxane copolymer with both ends blocked by trimethylsiloxy groups, dimethylsiloxane-methylphenylsiloxane-methylvinylsiloxane copolymer with both ends blocked with trimethylsiloxy groups, methyl (both ends blocked with dimethylvinylsiloxy groups)
3,3,3-)lifluoropropyl)polysiloxane, dimethylsiloxane-methyl(3,3,3-)lifluoropropyl)siloxane copolymer with dimethylvinylsiloxy groups capped at both ends, CH=CH(CH3)2 SiO+/
2 units and (CH3) 3 SiO+/2 units and S*
A polysiloxane consisting of 04/2 units is exemplified. In the present invention, the above organopolysiloxanes may be used in combination.

The organohydrodiene polysiloxane of component (n) has at least three silicon-bonded hydrogen atoms in one molecule. For example, methylhydrodienepolysiloxane with trimethylsiloxy groups blocked at both ends, dimethylsiloxane-7methylhydrodienesiloxane copolymer with both ends blocked with trimethylsiloxy groups, dimethylsiloxane-methylhydrosiloxane with both ends blocked with dimethylhydrodienesiloxy groups, etc. diene siloxane copolymer, dimethyl siloxane methylhydrogen siloxane cyclic copolymer, (C
H3) Copolymer consisting of 2 H3iO+/z units and S i O2/4 units, (CH3)3Sio172 units,
(CH3)2H3iO+/z unit and S i O4/
Examples include copolymers consisting of two units.

The platinum-based compound of component (V) is known chloroplatinic acid, a solution of this in alcohol or ketones, an aged solution of the same, a complex compound of chloroplatinic acid and olefins, and chloroplatinic acid. Examples include a complex compound of chloroplatinic acid and an alkenylsiloxane, a complex compound of chloroplatinic acid and a diketone, platinum black, and one in which platinum is supported on a carrier.

The amount of this component added is 0,000 ppm of the total amount of components (I) and (II).

(1), (n), (I[[), (rv),
The molar ratio of unsaturated groups to silicon-bonded hydrogen atoms in the composition of the present invention comprising component (v) is 0.5 to 1.8.
is within the range of

Preferably, the molar ratio is in the range of 0.8 to 1.2, and within this molar ratio range, the cured product has maximum mechanical strength, hardness, and impact resilience, and has minimum compression set, and has a good release property for toner. The moldability is also the best.

Although the compositions of the present invention can be prepared by simply mixing the various components together, the composition components (I
), (IV), and (V) component A solution,
(I), (n), (m), and (IV) components are prepared separately, and when converting the composition into a cured product, the two components of component A and B are separated into a predetermined amount. It is most convenient to mix at a mixing ratio of . In this case, the unsaturated group-containing component and =Si-H
Group-containing components and platinum catalyst components must not be included in the same package.

The elastic rotating body of the present invention comprises a porous inorganic fine powder having micropores supporting a silicone polyether copolymer having a polyoxyalkylene group in the side chain, at least one of an alkylsilane compound and dimethyl silicone oil, and a silicone rubber. The elastic body is made of a silicone rubber composition containing a silane compound containing an unsaturated group that is reactive with the silicone rubber composition, and a synthetic silicic acid whose surface has been modified with a silane compound that has an unsaturated group that is reactive with the silicone rubber composition. The fixing device of the present invention fixes a small amount of unfixed toner image formed on an image bearing material by heating and pressurizing the image bearing material by sandwiching and conveying the image bearing material between a pair of rollers.

Embodiments of the elastic rotating body and fixing device of the present invention will be described below based on the accompanying drawings.

FIG. 5 is a diagram mainly showing a vertical cross-sectional view showing a schematic configuration of a fixing device including the elastic rotating body of the present invention as a pressure roller. In the figure, reference numeral 1 denotes a fixing roller, and the fixing roller l has a heat-resistant and mold-releasing resin layer 3 made of PFA, PTFE, etc. formed on the outer surface of a core metal 2 made of aluminum, iron, stainless steel, etc. There is.

A heating means 9 such as a heater is included inside the core metal 2.

A pressure roller 4 is pressed against the fixing roller 1 by a spring or the like (not shown) and is driven to rotate. The pressure roller 4 has an elastic layer 6 made of a silicone rubber composition according to the present invention formed on a core metal 5 made of iron, stainless steel, or the like.

A thermistor 8 for detecting the temperature of the fixing roller 1 and a cleaner for cleaning the surface of the fixing roller 1 by contacting the fixing roller 1 may be provided around the fixing roller 1. An entrance guide 12 and the like for guiding the transfer material 11 between the fixing roller 1 and the pressure roller 4 are provided. On the other hand, a conductive leaf spring 13 for grounding is in contact with the core metal 5 of the pressure roller 4 .

In a fixing device including the above-mentioned elastic body of the present invention as a pressure roller, the elastic surface layer of the present invention can prevent or suppress charging, so that the amount of toner adhering to the surface of the fixing roller is significantly reduced; Problems such as image defects such as offset and contamination due to toner adhesion to the surface of the pressure roller are eliminated. Furthermore, transportation problems such as paper wrapping and paper curling are also solved.

In the accompanying drawings, FIG. 6 is a cross-sectional side view showing a very schematic configuration of an example of the device. Reference numerals 1 and 2 denote a heat roller (hereinafter referred to as a fixing roller) and a pressure roller, which are supported by bearings vertically in parallel and brought into moderate pressure contact with each other, and are driven to rotate in the direction of the arrow.

The fixing roller 1 is a hollow roller 11 made of metal such as aluminum.
The outer peripheral surface of the core metal has an elastic coating layer 12 coated with the silicone rubber composition of the present invention, and a heater 13 such as a halogen heater rod is inserted into the core metal, and the heat generated by the heater heated. Then, an automatic temperature control means (not shown) controls the power supply to the heater 13 on and off, or controls the amount of power supply, so that the temperature of the outer circumferential surface of the fixing roller is always maintained at a predetermined constant temperature. The pressure roller 2 has a core 21 made of a metal such as iron or aluminum, and its outer peripheral surface is covered with a relatively thick layer 22 of an elastic material such as rubber. The silicone rubber composition of the present invention may be used in the elastic material layer. 3 is a device for applying a release aid such as dimethyl silicone oil to the outer circumferential surface of the fixing roller l; this example uses a long web member 31 impregnated in advance with a release aid having a fairly high viscosity. The rolled web member is attached and held on the unwinding shaft 32, the free end of the rolled web member is locked to the winding shaft 33, and the portion of the web member between the unwinding shaft and the winding shaft is pressed and fixed by the roller 34. A configuration in which the roller 1 surface is pressed and the roll-wound web member on the feed-out shaft side is wound up little by little toward the take-up shaft side, thereby coating the outer circumferential surface of the fixing roller 1 with the impregnating release agent of the web member. belongs to. This web member also serves as a cleaning member for the outer surface of the fixing roller.

When the fixing roller 1 and the pressure roller 2 are in a rotationally driven state, an image forming mechanism (not shown) such as an electrophotographic method or an electrostatic recording method is used to remove unfixed images at the nip portion 4 between the two rollers. When an image support material (transfer material, electrofax paper, electrostatic recording paper, etc.) 5 on which a toner image T is formed and carried is introduced and passed with the toner image bearing surface side facing the fixing roller 1, the toner image T is The heat of the fixing roller 1 and the mutual pressing force of the fixing roller 1 and the pressure roller 2 are used to sequentially heat and pressure fix the image onto the surface of the image support material 5 as a permanently fixed image.

In addition, 6 is a separating claw member that is used to reliably separate the image support material 5 from the surface of the fixing roller 1, 7 is a sensor that detects the outer peripheral temperature of the fixing roller 1 in order to adjust the temperature of the fixing roller 1, and W is a fixing roller. The width dimension of the mutual contact portion of the roller 1 and the pressure roller 2 indicates the lub width.

In the fixing roller l, the layer thickness of the releasable material 12 covering the outer periphery of the core metal 11 is generally quite thin so that the heater heat can be quickly conducted and replenished to the outer surface of the material layer, that is, the outer peripheral surface of the fixing roller. (for example, about 0.5 mm).

When the silicone rubber composition of the present invention is used for the coating material layer 12 of the fixing roller 1, since the cured product of the composition is an elastic body, the surface unevenness of the support material 5 itself and the toner image T placed on the support layer are reduced. The outer surface of the elastic body coating layer is deformed in response to the unevenness of the toner image T, so that the outer surface of the elastic body covering layer is deformed to uniformly contact each part with the uneven toner image T. The fixed image, that is, the image quality is improved.Therefore, image collapse, gloss, toner scattering, etc. that occur when a rigid coating layer is used are improved.

Furthermore, since the composition of the present invention can prevent or suppress electrification, it can significantly reduce the amount of toner adhering to the roller surface, thereby preventing image defects such as offset and contamination due to toner adhesion to the roller surface. This also solves transportation problems such as paper wrapping and curling.

In addition, by gradually supplying the silicone polyether copolymer supported on the porous inorganic fine powder having micropores into the silicone rubber, good antistatic effect and antistatic effect are maintained over a long period of time. Conveyance problems such as contamination due to toner adhesion to the roller surface, paper wrapping around the roller, and paper curling can be prevented for a long time. Furthermore, at least one of the alkylsilane compound and dimethyl silicone oil in the composition and the unsaturated group of the synthetic silicic acid whose surface has been modified with the silane compound containing an unsaturated group react with the silicone rubber (crosslinking reaction). This improves mechanical strength and makes it possible to obtain sufficient durable strength.

〔Example〕

Next, the present invention will be explained based on examples.

[Example 1] (1); Total number of vinyl groups consisting of dimethylpolysiloxane end-blocked with vinyl groups and dimethylpolysiloxane end-blocked with vinyl groups in side chains is 8.0×10-”m o
Vinyl group-containing dimethylpolysiloxane with I/g...ioo parts by weight (
■): The number of silicon-bonded hydrogen atoms is 2. OXlo-amo
l/g of methylhydrodiene polysiloxane...
・7.15 parts by weight (■): Platinum catalyst ...0.001 parts by weight (■) Vinyl group-containing surface-modified hydrated synthetic silicic acid whose surface was modified with dimethyl silicone oil and a vinyl group-containing silane compound. ...10 parts by weight The above hydrous synthetic silicic acid was prepared as follows.

Average particle size is 8.6 μm, specific surface area is 114 rli'
Hydrophobic synthetic silicic acid whose surface has been treated with dimethyl silicone oil (Hydrophobic silica NIPSI manufactured by Nippon Silica)
100 parts by weight of L■5S30P) was introduced into a stirring device, and 12 parts by weight of vinyltriethoxysilane was gradually added dropwise with forced stirring.Then, the mixture was taken out from the stirring device and air-dried at 100°C for 1 hour to obtain the desired vinyl. A group-containing surface-modified hydrous synthetic silicic acid was obtained. The amount of vinyl groups in this powder was 3.8 x 10'' per gram of powder.

(V): Porous inorganic fine powder having micropores supporting a silicone polyether copolymer having a polyoxyalkylene group in the side chain...5 parts by weight The above porous inorganic fine powder was prepared as follows. did.

Average particle size 25 μm 1 pore size approx. O1~10μm1 oil absorption 500mI2/100g, apparent specific gravity 0.1, BE
100 parts by weight of gyrolite-type calcium silicate (Fluorite R manufactured by Tokuyama Soda) with a specific surface area of ttsrrf/g was introduced into a stirring device, and 100 parts by weight of a polyoxyalkylene group-containing silicone polyether copolymer (TSF manufactured by Toshiba Silicone) was introduced into a stirring device.
4452) was gradually dropped into the stirred calcium silicate fine powder, and after dropping all (400 parts),
After stirring was continued for a while, the mixture was taken out from the stirring device to obtain calcium silicate fine powder supporting a silicone polyether copolymer having a polyoxyalkylene group.

(■) Iron dioxide...1 weight fraction components (I), (n), (m), (rV), (V) and (
Vl) is a component constituting the composition according to the present invention, and was prepared so that the total amount of vinyl groups and silicon-bonded hydrogen atoms in the composition were equimolar. Each component was packaged in a two-component format as shown below.

Both A and B solutions were prepared by uniformly mixing them. The thus obtained liquid A and liquid B were mixed at a weight ratio of 100:110, defoamed, and then heated in a hot press at 150°C for 10 minutes to obtain a rubber-like elastic body. The rubber-like elastic body was further subjected to post-curing at 200° C. for 4 hours.

[Example 2 (I): Total number of vinyl groups consisting of dimethylpolysiloxane end-blocked with vinyl groups and dimethylpolysiloxane end-blocked with vinyl groups containing side chain vinyl groups is 8.0XIO-'m o
l/g of vinyl group-containing dimethylpolysiloxane.
...ioo parts by weight (■): The number of silicon-bonded hydrogen atoms is 2. OX 10-”
mol/g of methylhydrodienepolysiloxane...7.15 parts by weight (■): Platinum catalyst...0.001 parts by weight (■): The surface of hydrophobized anhydrous synthetic silicic acid is coated with a vinyl group-containing silane compound. Surface-modified synthetic silicic acid containing vinyl groups modified with...10 parts by weight
Prepared as below.

Hydrophobized anhydrous synthetic silicate Aerosil @ R812 manufactured by Degussa with a specific surface area of 200 d/g and a bulk specific gravity of 50 g/l
0 parts by weight was introduced into a stirring device, and 12 parts by weight of vinyltriethoxysilane was gradually added dropwise with forced stirring. After the dropwise addition was completed, the mixture was taken out from the stirring device and air-dried at 100°C for 1 hour to obtain the desired vinyl group. A containing surface-modified anhydrous synthetic silicic acid was obtained. The vinyl base weight of this powder was 3.8×10 2 o/(1 g of powder).

(V): Porous inorganic fine powder supporting silicone polyether copolymer...5 parts by weight (■)
: Iron oxide...1 weight iron component (
I), (n), (m), (IV), (V) and (Vl
) is a component constituting the composition according to the present invention, and was prepared so that the total amount of vinyl groups and silicon-bonded hydrogen atoms in the composition were equimolar. Each component was packaged in a two-component format as shown below.

Both A and B solutions were prepared by uniformly mixing them. The thus obtained liquid A and liquid B were mixed at a weight ratio of 100:110, defoamed, and then heated in a hot press at 150°C for 10 minutes to obtain a rubber-like elastic body. The rubber-like elastic body was further post-cured at 200° C. for 4 hours.

[Example 3] A composition according to the present invention was obtained from component (I), component (n), component (m), component (V), component (VT) of Example 1 and the component (■) shown below. Ta.

(■) Ingredient: Vinyl group-containing surface-modified hydrous synthetic silicic acid whose surface was modified with methyltrimethoxysilane and vinyl group-containing silane...10 parts by weight The above modified hydrous synthetic silicic acid was prepared as follows: did.

Hydrous synthetic silicic acid with an average particle diameter of 2 μm and a specific surface area of 170 rrf/g (NIPSILoN300A manufactured by Nippon Silica)
1 part by weight of 100 parts by weight was introduced into a stirring device, and 3 parts by weight of methyltrimethoxysilane was gradually added dropwise while stirring forcibly. After the addition was completed, 12 parts by weight of vinyltriethoxysilane was gradually added dropwise in the same manner. After the dropping, the powder was taken out from the stirring device, air-dried at 100°C for 1 hour, and -
The desired surface-modified hydrous synthetic silicic acid containing vinyl groups was obtained.

The amount of vinyl groups in this powder was 3.8 x 10'' per tg of powder.

Components (I), (II), (I[[), (V
), (VI), and (■) are components constituting the composition according to the present invention, and were prepared so that the total amount of vinyl groups and silicon-bonded hydrogen atoms in the composition were equimolar. Each component was packaged in a two-component format as shown below.

Both A and B solutions were prepared by uniformly mixing them. The thus obtained liquid A and liquid B were mixed at a weight ratio of 100:110, defoamed, and then heated in a hot press at f500c for 10 minutes to obtain a rubber-like elastic body. The rubber-like elastic body was further coated with 20
Post-curing was performed at 0°C for 4 hours.

[Comparative Example 1 Liquid A with a viscosity of 800 poise consisting of 100 parts by weight of covinyl group-containing dimethylpolysiloxane, 5 parts by weight of anhydrous synthetic silicic acid, 20 parts by weight of quartz powder, 1 part by weight of red iron and a platinum catalyst, and a vinyl group-containing solution 100 parts by weight of a mixture of diorganopolysiloxane and silicon-bonded hydrogen-containing siloxane, 5 parts by weight of anhydrous synthetic silicic acid, 20 parts by weight of quartz powder,
A liquid B having a viscosity of 600 poise and consisting of 1 part by weight of red red iron was mixed at a weight ratio of 100:100, and after defoaming treatment, it was heated in a hot press at 150° C. for 10 minutes to obtain a rubber-like elastic body.

The rubber-like elastic body was further post-cured at 200° C. for 4 hours.

[Comparative Example 2] Component (I): Dimethylpolysiloxane end-blocked with vinyl groups and dimethylpolysiloxane end-blocked with side chain vinyl groups, total number of vinyl groups is 8, OX 10-6
mol/g vinyl group-containing dimethylpolysiloxane
...10,000 parts by weight):
The number of silicon-bonded hydrogen atoms is 2.0X10-'mol
/g of methylhydrodiene polysiloxane
...7.15 parts by weight ingredients (
■): Platinum catalyst...0.00101 parts by weight Components I), (I[), and (m) are components constituting the composition according to the present invention, and the total amount of vinyl groups and silicon It was prepared so that the amount of bonded hydrogen atoms was approximately equimolar.

Each component was packaged in a two-component format as shown below.

υshi component (I) ... 50 parts by weight component (m) ... 0.001 part by weight Mouth component (I) ... 43.33 parts by weight component (n)
... 6.67 parts by weight Both solutions A and B were uniformly mixed and prepared respectively. The thus obtained liquid A and liquid B were mixed at a weight ratio of 100:100, and after defoaming treatment, the mixture was heated in a heat press at 150°C for 10 minutes to obtain a rubber-like elastic body formed from a silicone rubber composition. I got it. The rubber-like elastic body was further post-cured at 200° C. for 4 hours.

[Comparative Example 3] Component (I): Dimethylpolysiloxane end-blocked with vinyl groups and dimethylpolysiloxane end-blocked with side chain vinyl groups, total number of vinyl groups is 8, OX 10-6
mol/g vinyl group-containing dimethylpolysiloxane
...10,000 parts by weight);
The number of silicon-bonded hydrogen atoms is 2,0XIO-”mol
/g of methylhydrodiene polysiloxane
...7.15 parts by weight ingredients (
■): Platinum catalyst: 0.00101 parts by weight ■): Vinyl group-containing surface-modified hydrous synthetic silicic acid whose surface was modified with dimethyl silicone oil and a vinyl group-containing silane compound: 10 parts by weight ( V); Red Garla...1 part by weight acid content (rV) is
Prepared as below.

The average particle size is 8.6 μm and the specific surface area is 114rr?
/ g of dimethyl silicone oil (approximately 9% by weight
) 100 parts by weight of hydrated synthetic silicic acid fine powder (hydrophobic silica NIPSIL@5S30P manufactured by Nippon Silica) was introduced into a stirring device, and 12 parts by weight of vinyltriethoxysilane was gradually added dropwise with forced stirring. The mixture was taken out from the stirring device and air-dried at 100° C. for 1 hour to obtain a surface-modified hydrous synthetic silicic acid containing reactive vinyl groups. The amount of vinyl groups in this powder was approximately 3.8×10 2 o vinyl groups per gram of powder.

Components (1), (I), (m), (IV), and (V) are components constituting the composition according to the present invention, and the total amount of vinyl groups and silicon-bonded hydrogen atoms in the composition are Each component was prepared in a two-component format as shown below.

Component (I)...45.35 parts by weight component (It[)...0.00101 parts by weight component IV)
... 4.23 Weight part component (V) ... 0.43
Parts by weight Ingredients (I)...39.29 Parts by weight Ingredients (■)... 6.05 Parts by weight Ingredients (IV)... 4.23 Parts by weight Ingredients (V)...
- 0.43 parts by weight Both solutions A and B were mixed uniformly and prepared respectively.

The thus obtained liquid A and liquid B were mixed at a weight ratio of 100:100, and after defoaming treatment, the mixture was heated in a heat press at 150°C for 10 minutes to obtain a rubber-like elastic body formed from a silicone rubber composition. I got it. The rubber-like elastic body was further subjected to post-curing at 200°C for 4 hours.

Table 1 below shows the physical properties of the rubber-like elastic bodies and toner releasability in Examples 1 to 3 and Comparative Examples 1 to 3.

Table 1 (*) Toner releasability: Rubber test piece (20 x 60 x 15 m
50 circular toner images with a diameter of 2 mm and a thickness of 50 μm are formed on the substrate m), and the toner images are heated and melted at 180'C (ambient temperature) for 30 minutes, and then cooled to room temperature.

An adhesive tape is pasted on the melted and solidified toner image, and a roller with a constant load (1 kg weight) is moved back and forth 10 times over the adhesive tape, and then the tape is removed. The toner peeling state at this time is classified into 5 stages,
The number of particles at each stage was calculated and scored, and the sum of the scores at each stage was divided by the total score (50×4=200 points) to determine the toner releasability (%). The toner peeling state was classified as follows.

A: Completely peeled off (4 points) State between BAA and C (3 points) C: 1/2 of the total area peeled off (2 points) D: C and E
(1 point) E: Completely remaining state (0 points) The sample used in this test was aged at 200° C. for 4 hours.

Example 11 Regarding the rubber-like elastic body obtained in Comparative Example 1,
The antistatic and static neutralizing effects were investigated using the following methods. 20
After applying 15,000 V by corona discharge to a rubber test piece of mm x 60 mm x 2 mm for a predetermined time (1 second),
Immediately, changes in potential on the surface of the rubber test piece were measured with a surface electrometer using a sensitive plate probe. The results are shown in FIG.

[Example 4] The amount of the vinyl group-containing surface-modified hydrous synthetic silicic acid whose surface was modified with the dimethyl silicone oil and vinyl group-containing silane of Example 1 was adjusted to 100% by weight of the vinyl group-containing dimethylpolysiloxane of component (I). component (10 parts by weight)
The amount of methylhydrodiene polysiloxane (n) was varied. At this time, the total amount (total number of moles) of the silicon-bonded vinyl group of component (1) and the vinyl group of the vinyl group-containing surface-modified hydrous synthetic silicic acid whose surface was modified with dimethyl silicone oil and vinyl group-containing silane, and the component ( silicon-bonded hydrogen atom (-3
molar ratio -8i -H/V i (V
A composition corresponding to (i represents a vinyl group) was prepared and cured by heating at 150° C. for 10 minutes using a hot press to obtain a rubber-like elastic body. The rubber-like elastic body was post cured at 200° C. for 4 hours. The hardness and impact resilience of the rubber-like elastic body,
The results of toner releasability are shown in FIGS. 1 to 3. When the vinyl groups and silicon-bonded hydrogen atoms in the composition were substantially equimolar, the hardness and impact resilience showed the maximum values, and the toner releasability showed the maximum value.

[Example 5] A fixing roller for a thermopressure fixing device having the silicone rubber composition of the present invention as an elastic material layer was manufactured as follows.

First, the outer diameter of the central part is 58.3 mm (thickness 6.5 m).
m.

The surface of the aluminum core metal with a reverse crown depth of 150 μm was sandblasted, degreased and dried, and then a siloxane primer was applied to the surface, and the surface was heated at 130°C for 1
It was heated and air-dried for 5 minutes. Next, the core metal was placed in a cylindrical mold that had been preheated to 150°C.

The weight ratio of liquid A and liquid B prepared in Example 1 was 100:1.
The mixture was uniformly mixed at 10° C. and degassed, and then injected into a cylindrical mold and held at the same temperature (150° C.) for 5 minutes to harden. The silicone rubber coating layer thickness of the silicone rubber coated fixing roller taken out from the mold after curing is 0.5 m.
It was m.

Using the fixing roller obtained above, a heat fixing type fixing device shown in FIG. 6 was installed, and a continuous sheet feeding fixing process test was conducted under the following conditions.

・Surface control temperature of fixing roller 1...180 to 190°C
・Oil applicator 3...viscosity at 25℃ is 10,000C
Web type equipped with a web (product name Nomex Paper Web) impregnated with S dimethyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product number KF96), web feed speed 1 m / 10,000 sheets (A4 size) ).

- Passing paper: A4 size transfer paper on which an unfixed toner image of the test pattern was formed.

・Paper feeding speed: 70 sheets/min.

φ Nip width W between fixing roller 1 and pressure roller 2...9~
10 mm0 [Example 6] A fixing roller was manufactured in the same manner as in Example 5 except that the silicone rubber composition of the present invention prepared in Example 2 was used. Using the thus obtained fixing roller, the continuous paper passing fixing process test shown in Example 5 was conducted.

[Comparative Example 4] A fixing roller was manufactured in the same manner as in Example 5 except that the dimethyl silicone rubber composition prepared in Comparative Example 1 was used. Using the thus obtained fixing roller, the continuous paper passing fixing process test shown in Example 5 was conducted.

[Comparative Example 5] A fixing roller was manufactured in the same manner as in Example 5 except that the dimethyl silicone rubber composition prepared in Comparative Example 3 was used. Using the thus obtained fixing roller, the continuous paper passing fixing process test shown in Example 5 was conducted.

Table 2 below shows the results of the continuous paper feeding fixing process test for Examples 5, 6, Comparative Examples 4, and 5.

Table 1 [Effects of the Invention] The present invention provides a porous inorganic fine powder having micropores supporting a silicone polyether copolymer having a polyoxyalkylene group in its side chain, and at least one of an alkylsilane compound and a dimethyl silicone oil. By incorporating into a silicone rubber composition a synthetic silicic acid fine powder whose surface has been modified with a silane compound having an unsaturated group,
It has made it possible to prevent or suppress electrification of rubber molded products, and it has also made it possible to improve the mechanical strength of silicone rubber by adding a small amount of filler.

When the composition of the present invention is used, for example, as an elastic surface layer of a fixing roller of an image fixing device in an image forming apparatus such as an electronic copying machine, or a fixing roller such as a pressure roller, charging on the roller surface is prevented or controlled. As a result, the amount of toner adhering to the roller surface is significantly reduced, making it possible to prevent image defects such as offset and contamination due to toner adhesion to the roller surface. The problem will also be resolved. In addition, since the silicone polyether copolymer supported on the porous inorganic fine powder having micropores is gradually supplied into the silicone rubber, good antistatic effect and antistatic effect are maintained over a long period of time. As a result, transportation problems such as contamination due to toner adhesion to the roller surface, paper wrapping around the roller, and paper curling can be prevented for a long period of time, making it possible to dramatically improve the durability of the roller.

In addition, the composition of the present invention has excellent mechanical strength, making it possible to obtain sufficient roller durability strength.

A fixing device using a fixing roller coated with the silicone rubber composition of the present invention solves problems such as paper curl, paper wrinkles, paper jams, toner offset, and toner adhesion stains during conveyance and fixing, and has sufficient durability. It is possible to maintain excellent mold releasability and fixing power as well as properties.

The silicone rubber composition of the present invention may be used as a covering material for both the fixing roller and the pressure roller among the fixing rollers, or either one of the fixing roller and the pressure roller may be used.

[Brief explanation of drawings]

FIG. 1 shows a graph showing the relationship between the molar ratio of SiH/Vi and hardness in Example 4, and FIG. 2 shows a graph showing the relationship between the molar ratio of SiH/Vi and impact resilience. FIG. 3 shows a graph showing the relationship between the molar ratio of -3iH/Vi and toner releasability, and FIG.
3... Web type oil application device 105... Image support material 107... Temperature sensor 113... Heater T... Unfixed toner image A diagram showing a schematic configuration of an example of a toner image fixing device is shown. . 1... Fixing roller 2... Pressure roller 4... Pressure roller 6... Elastic layer 10... Toner image 11... Image support material 101... Fixing roller] 3rd ward Tokifu■ 0Δ ri8/・4!・2 15++/, c beg le ratio] /・0 -5 + H//V [lself le r and J 8kitP1 呵 (now)

Claims (9)

[Claims] (1) Silicone rubber, porous inorganic fine powder having micropores supporting a silicone polyether copolymer having a polyoxyalkylene group in the side chain, and addition with an alkylsilane compound, dimethylsilicone oil, or a mixture thereof 1. A silicone rubber composition comprising: a silane compound containing an unsaturated group that is reactive with reactive silicone rubber; and a synthetic silicic acid fine powder whose surface has been modified with a silane compound. (2) The silicone rubber composition according to claim 1, wherein the silicone rubber is a radical-reactive silicone rubber. (3) The main chain skeleton of the organopolysiloxane that makes up silicone rubber is a formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
In the formula, R_1 and R_2 represent an alkyl group, an aryl group, or a polyfluoroalkyl group, and m represents a positive integer. ] The silicone rubber composition according to claim 1 or 2. (4) A molded article formed from the silicone rubber composition according to claim 1. (5) The molded article according to claim 4, wherein the silicone rubber is a radical-reactive silicone rubber. (6) An elastic rotating body comprising an elastic body having a surface layer formed from the silicone rubber composition according to claim 1. (7) The elastic rotating body according to claim 6, wherein the silicone rubber is a radical-reactive silicone rubber. (8) In a fixing device that heats and presses an unfixed toner image formed on an image carrier by transporting the image carrier between at least a pair of rollers, the surface layer of at least one roller is made of an elastic material. A fixing device characterized in that the elastic body is made of the silicone rubber composition according to claim 1. (9) The fixing device according to claim 8, wherein the silicone rubber is a radical-reactive silicone rubber.