JP2006265340A - Nonconductive silicone rubber composition for fixing roll or fixing belt and fixing roll and fixing belt therefrom - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To relate to a fixing roll and a fixing belt which are used in a copying machine, a laser beam printer, a facsimile and the like; and provide a nonconductive silicone rubber composition for fixing roll or fixing belt having excellent antistatic property, can maintain the antistatic property even in the case where they are exposed to high temperature for a long time and causes no deterioration of rubber physical property, compression permanent deformation; and provide a fixing roll and fixing belt using the same. <P>SOLUTION: The nonconductive silicone rubber composition for fixing roll or fixing belt comprises 100 pts.mass of an organopolysiloxane bearing at least two alkenyl groups bonding to at least two silicon atoms in one molecule, an effective amount of a curing agent for curing the organopolysiloxane and 0.001 to 2 pts.mass of antistatic agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fixing roll and a fixing belt used in a copying machine, a laser beam printer, a FAX, and the like. Specifically, the antistatic performance is excellent and the antistatic performance can be maintained even when exposed to a high temperature for a long time. The present invention relates to an insulating silicone rubber composition for a fixing roll or a fixing belt that gives a cured product, and a fixing roll and a fixing belt using the same.

  Silicone rubber is excellent in electrical insulation, heat resistance, weather resistance, and flame retardancy, and has been used as a coating material for fixing rolls such as heater rolls and pressure rolls of copying machines and laser beam printers. Recently, as the speed of copying and color copying has become widespread, the fixing roll is also required to have low hardness, which cannot be handled with conventional metals or fluororesins. Many types of coating are used. In addition, mainly for heat roll rubber, not only the roll type coated on the core metal but also heat resistant resin such as polyimide, in order to shorten the waiting time when starting the machine and from the viewpoint of energy saving of the machine itself A fixing belt type in which a silicone rubber is coated on a metal belt such as aluminum, aluminum, nickel, etc., and a fluororesin layer is further provided thereon as a durable release layer is also widely used.

However, as the speed of these copying machines, laser beam printers, fax machines, etc. increases, the fixing device increases the time required for fixing, so that the rubber hardness is reduced and the fixing width (nip width) is increased or inorganic filling is performed. Rubber materials with high thermal conductivity that contain a large amount of the agent are used.
On the other hand, a low thermal conductive material is used for the pressure roll disposed relative to the heater roll or belt so as not to let the heat received from the heater roll or belt escape. As such a low heat conductive material, a method of blending a hollow filler with silicone rubber is known.

  However, as the fixing speed increases and the nip width increases, the static electricity that has been a problem in the past causes the paper not to leave the fixing device such as a roll or a belt, or the image is distorted. The problem such as has occurred.

In order to avoid such trouble, as an antistatic agent, a polyether-based compound (Japanese Patent Publication No. 2002-500237: Patent Document 1) or carbon (Japanese Patent Publication No. 2002-507240: Patent Document 2, Japanese Patent Laid-Open No. 2002-2002). No. 327122: Patent Document 3) is known to be blended. However, when a polyether-based compound is used, the polyether is decomposed at a high temperature, so that not only the antistatic effect is not exhibited, but also the physical properties of the rubber are deteriorated. When carbon is used, in addition to the problem that compression set deteriorates, high heat conductive material with a large amount of filler, and conversely with low heat conductive material with a large amount of hollow filler, It was difficult.
Japanese Patent Laid-Open No. 2003-82232 (Patent Document 4) exemplifies a silicone rubber for a semiconductive roller in which a lithium salt is blended, but this is not related to an insulating material, and is based on ionic conduction. In order to make the resistance semiconductive, a large amount of ionic conductive agent is required, so that the physical properties of rubber are greatly reduced. Actually, in the examples of Japanese Patent Application Laid-Open No. 2003-82232, there is only what is used in combination with carbon, and no mention is made of deterioration of compression set due to carbon.
Furthermore, Japanese Patent Application Laid-Open No. 10-48888 (Patent Document 5) describes a method for preventing charging by adding an organic phosphorus salt. However, the addition of an organic phosphorus salt has an adverse effect on compression set. In addition, when the rubber material is an addition-curing type, it becomes a catalyst poison and the rubber curing becomes insufficient.

Special Table 2002-500237 Special table 2002-507240 gazette JP 2002-327122 A JP 2003-82232 A Japanese Patent Laid-Open No. 10-48888

  The present invention has been made in view of the above circumstances, is excellent in antistatic performance, can maintain antistatic performance even when exposed to high temperature for a long time, and does not deteriorate rubber physical properties or compression set. It is an object of the present invention to provide a fixing roll or an insulating silicone rubber composition for a fixing belt that gives a cured product, and a fixing roll and a fixing belt using the same.

  As a result of intensive studies to achieve the above object, the present inventors have found that an insulating composition obtained by adding a specific amount of an antistatic agent to a conventional thermosetting organopolysiloxane composition is used as a copying machine. When used as a silicone rubber layer for fixing rolls and fixing belts such as laser beam printers and fax machines, it has excellent antistatic performance and can maintain antistatic performance even when exposed to high temperatures for long periods of time. Rubber properties and compression set As a result, the present invention has been found.

Accordingly, the present invention provides the following insulating silicone rubber composition for a fixing roll or fixing belt, as well as the fixing roll and fixing belt.
[1] An antistatic agent is added to 100 parts by mass of an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule and an effective amount of a curing agent for curing the organopolysiloxane. An insulating silicone rubber composition for a fixing roll or fixing belt containing 0.001 to 2 parts by mass.
[2] The insulating silicone rubber composition for a fixing roll or fixing belt according to [1], further comprising 0.1 to 100 parts by mass of a hollow filler having an average particle size of 200 μm or less.
[3] The insulating silicone rubber composition for a fixing roll or fixing belt according to [1] or [2], wherein the antistatic agent is a lithium salt.
(4) antistatic _{agents, LiBF 4, LiClO 4, LiPF} 6, LiAsF 6, LiSbF 6, LiSO 3 CF 3, LiN (SO 2 CF 3) 2, LiSO 3 C 4 F 9, LiC (SO 2 CF 3 3) The insulating silicone rubber composition for fixing rolls or fixing belts according to [3], which is one or more selected from ₃ and LiB (C ₆ H ₅ ) ₄ .
[5] The insulating silicone rubber composition for a fixing roll or fixing belt according to any one of [1] to [4], wherein the silicone rubber composition is an addition-curable silicone rubber composition.
[6] The insulating silicone rubber composition for a fixing roll or fixing belt according to any one of [1] to [4], wherein the silicone rubber composition is an organic peroxide curable silicone rubber composition.
[7] For the fixing roll or fixing belt according to any one of [1] to [6], wherein the volume resistivity of the cured product is 1 G (giga) Ω · m or more (that is, 1 × 10 ¹¹ Ω · cm or more). Insulating silicone rubber composition.
[8] A fixing roll having a silicone rubber layer formed on the outer peripheral surface of the roll shaft, wherein the silicone rubber forming the silicone rubber layer is the insulating silicone rubber composition according to any one of [1] to [7] A fixing roll characterized by being cured.
[9] A fixing roll in which a fluororesin layer or a fluororubber layer is formed on the outer peripheral surface of a roll shaft via a silicone rubber layer, and the silicone rubber forming the silicone rubber layer is [1] to [7] A fixing roll obtained by curing any of the insulating silicone rubber compositions.
[10] A fixing belt in which a silicone rubber layer is formed on a belt base material, wherein the silicone rubber forming the silicone rubber layer is the insulating silicone rubber composition according to any one of [1] to [7]. A fixing belt characterized by being cured.
[11] A fixing belt in which a fluororesin layer or a fluororubber layer is formed on a belt base material via a silicone rubber layer, and the silicone rubber forming the silicone rubber layer is any of [1] to [7] A fixing belt obtained by curing any of the insulating silicone rubber compositions.

  The insulating silicone rubber composition of the present invention is excellent in antistatic performance, can maintain antistatic performance even when exposed to high temperature for a long time, and has an insulating cured product that does not deteriorate rubber physical properties or compression set. The cured product can be suitably used as a silicone rubber layer of a fixing roll or fixing belt of a copying machine, a laser beam printer, a FAX, or the like.

  The insulating silicone rubber composition for a fixing roll or fixing belt of the present invention includes an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule, and a curing agent for curing the organopolysiloxane. Further, it contains an antistatic agent, preferably a hollow filler having an average particle diameter of 200 μm or less.

The antistatic agent used in the present invention, lithium salts are preferred, _{specifically, LiBF 4, LiClO 4, LiPF} 6, LiAsF 6, LiSbF 6, LiSO 3 CF 3, LiN (SO 2 CF 3) 2, Examples thereof include LiSO ₃ C ₄ F ₉ , LiC (SO ₂ CF ₃ ) ₃ , LiB (C ₆ H ₅ ) _{4 and the} like. These may be used alone or in combination of two or more.

In the present invention, other ionic conductive agents, electronic conductive agents such as carbon, and other organic polymer antistatic agents such as polyether are used in combination as long as the performance of the insulating silicone rubber composition is not impaired. You can also Here, in the present invention, the insulating property means that the volume resistivity of the composition and / or the cured product is 1 × 10 ¹¹ Ω · cm or more.

  The addition amount of the antistatic agent is 0.001 to 2 parts by mass, preferably 0.002 to 100 parts by mass of the organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule. 1 part by mass, more preferably 0.005 to 0.5 part by mass. When the amount is less than 0.001 part by mass, the antistatic effect is insufficient. When the amount is more than 2 parts by mass, the rubber physical properties, insulating properties, heat resistance, and the like of the silicone rubber are adversely affected.

  The insulating silicone rubber composition of the present invention preferably contains a hollow filler. As this hollow filler, any glass balloon, silica balloon, carbon balloon, phenol balloon, acrylonitrile balloon, vinylidene chloride balloon, alumina balloon, zirconia balloon, shirasu balloon and the like may be used. Further, an inorganic filler or the like may be attached to the surface for the purpose of giving the strength of the hollow filler.

The average particle size of the hollow filler is 200 μm or less, preferably 150 μm or less. If it is larger than 200 μm, the hollow filler is destroyed by the injection pressure at the time of molding, or the surface roughness after roller molding becomes large. The lower limit value of the average particle diameter is preferably 5 μm or more, particularly 10 μm or more.
In the present invention, the average particle diameter can be determined, for example, as a cumulative weight average value D ₅₀ (or median diameter) in a particle size distribution measuring apparatus using a technique such as a laser beam diffraction method.

  Moreover, it is preferable that the true specific gravity of a hollow filler is 0.01-1.0, More preferably, it is 0.02-0.50. If it is less than 0.01, not only is it difficult to mix and handle, but the pressure resistance of the hollow filler may be insufficient and may be destroyed during molding, and if it is greater than 1.0, the shell thickness of the hollow filler is large. Addition effects such as weight reduction and thermal conductivity reduction may not be obtained. Here, the true specific gravity is a value obtained by a particle density measurement method (calculated from the volume in isopropyl alcohol).

  The blending amount of the hollow filler is preferably 0.1 to 100 parts by weight, more preferably 100 parts by weight of organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule. 0.5-50 mass parts, More preferably, it is 1.0-30 mass parts. If the amount is less than 0.1 parts by mass, the effect of addition may not be obtained. If the amount exceeds 100 parts by mass, not only the physical properties of the rubber are adversely affected, but blending may be difficult.

  The silicone rubber composition of the present invention is preferably an addition reaction curable organopolysiloxane composition or an organic peroxide curable organopolysiloxane composition.

In this case, the addition reaction curable organopolysiloxane composition is
(A) an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule;
(B) an organohydrogenpolysiloxane containing hydrogen atoms bonded to at least three silicon atoms in one molecule;
(C) It is preferable to contain an addition reaction catalyst, and the organic peroxide curable organopolysiloxane composition is
(A) The following average composition formula (3)
R _n SiO _{(4-n) / 2} (3)
(In the formula, R is the same or different unsubstituted or substituted monovalent hydrocarbon group, and n is a positive number of 1.98 to 2.02.)
An organopolysiloxane having an alkenyl group bonded to at least two silicon atoms in one molecule,
(B) It is preferable to contain an organic peroxide.

The organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule of the component (A) used in the addition reaction curable organopolysiloxane composition is represented by the following average composition formula (1): What is shown can be used.
R ¹ _a SiO _{(4-a) / 2} (1)
Wherein R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having the same or different carbon number of 1 to 10, preferably 1 to 8, and a is 1.5 to 2.8, preferably 1. (It is a positive number in the range of 8 to 2.5, more preferably 1.95 to 2.05.)

Here, the unsubstituted or substituted monovalent hydrocarbon group represented by R ¹ includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, and a neopentyl group. Alkyl groups such as hexyl group, cyclohexyl group, octyl group, nonyl group, decyl group, aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, aralkyl groups such as benzyl group, phenylethyl group, phenylpropyl group, etc. , Vinyl groups, allyl groups, propenyl groups, isopropenyl groups, butenyl groups, hexenyl groups, cyclohexenyl groups, octenyl groups and other alkenyl groups, and some or all of the hydrogen atoms of these groups are fluorine, bromine, chlorine, etc. Substituted with a halogen atom, a cyano group, etc., such as chloromethyl group, chloropropyl group, bromoethyl Group, trifluoropropyl group, cyanoethyl group and the like.

In this case, at least two of R ¹ must be alkenyl groups (preferably having 2 to 8 carbon atoms, more preferably 2 to 6). In addition, it is preferable that content of an alkenyl group is 0.005-20 mol% in all the organic groups (namely, R < ¹ >), especially 0.01-10 mol%. This alkenyl group may be bonded to a silicon atom at the end of the molecular chain, may be bonded to a silicon atom in the middle of the molecular chain, or may be bonded to both.

  The structure of this organopolysiloxane basically has a linear structure in which the main chain is composed of repeating diorganosiloxane units, and both ends of the molecular chain are blocked with triorganosiloxy groups, but partially branched. The structure may be a ring structure or a ring structure. The molecular weight is not particularly limited, and can be used from a low-viscosity liquid to a high-viscosity raw rubber-like one. It is preferably about 20,000, more preferably about 150 to 2,000.

In addition, the organohydrogenpolysiloxane containing hydrogen atoms bonded to at least 2, preferably 3 or more silicon atoms in one molecule of the component (B) is represented by the following average composition formula (2): Those having at least 2, usually 2 to 300, preferably 3 or more, more preferably 3 to 150, silicon-bonded hydrogen atoms in one molecule are suitably used.
R ² _b H _c SiO _{(4-bc) / 2} (2)
(In the formula, R ² is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, which are the same or different from each other; b is 0.7 to 2.1; 001 to 1.0 and b + c is a positive number satisfying 0.8 to 3.0.)

Here, examples of the monovalent hydrocarbon group for R ² include the same groups as those exemplified above for R ¹ , but those having no aliphatic unsaturated group are preferred. Further, b is preferably 0.8 to 2.0, c is preferably 0.01 to 1.0, b + c is preferably 1.0 to 2.5, and the molecular structure of the organohydrogenpolysiloxane is: The structure may be any of linear, cyclic, branched, and three-dimensional network. In this case, the number of silicon atoms in one molecule (or the degree of polymerization) is preferably 2 to 300, particularly about 4 to 150 at room temperature (25 ° C.). In addition, the hydrogen atom couple | bonded with a silicon atom may be located in any of the molecular chain terminal and the middle of a molecular chain, and may be located in both.

Examples of the organohydrogenpolysiloxane of the component (B) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, tris (dimethylhydrogensiloxy) methylsilane, Tris (dimethylhydrogensiloxy) phenylsilane, trimethylsiloxy group-capped methylhydrogenpolysiloxane at both ends, trimethylsiloxy group-capped dimethylsiloxane / methylhydrogensiloxane copolymer, dimethylhydrogensiloxy group-capped dimethylpolysiloxane at both ends , Both ends dimethylhydrogensiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, both ends trimethylsiloxy group-blocked methylhydrogensiloxane / diphenylsilo San copolymers, both end trimethylsiloxy-blocked methylhydrogensiloxane-diphenylsiloxane-dimethylsiloxane copolymers, copolymers consisting of (CH _{3) 2} HSiO _1/2 units and SiO _4/2 units, (CH ₃ ) Copolymers composed of ₂ HSiO _1/2 units, SiO _4/2 units, and (C ₆ H ₅ ) SiO _3/2 units.

  The blending amount of the organohydrogenpolysiloxane of the component (B) is 0.1 to 50 parts by weight, particularly 0.3 to 30 parts by weight with respect to 100 parts by weight of the organopolysiloxane of the component (A). preferable. The organohydrogenpolysiloxane has a molar ratio of hydrogen atoms bonded to silicon atoms in the component (B) (that is, SiH groups) to alkenyl groups bonded to silicon atoms in the component (A) of 0.5. -5 mol / mol, preferably 0.8 to 4 mol / mol, more preferably 1 to 3 mol / mol.

  The addition reaction catalyst for component (C) is a catalyst for promoting the hydrosilylation addition reaction between the alkenyl group in component (A) and the SiH group in component (B). Black, platinum chloride, chloroplatinic acid, reaction product of chloroplatinic acid and monohydric alcohol, complex of chloroplatinic acid and olefins, platinum catalyst such as platinum bisacetoacetate, palladium catalyst, rhodium catalyst Platinum group metal catalysts such as In addition, although the compounding quantity of this addition reaction catalyst can be made into a catalyst amount, 0.5-1,000 ppm with respect to the total mass of (A) and (B) component as a platinum group metal normally, especially 1-. It is preferable to blend about 500 ppm.

In addition, the organopolysiloxane of component (a) used in the organic peroxide-curable organopolysiloxane composition is represented by the following average composition formula (3), and is bonded to at least two silicon atoms in one molecule. Having an alkenyl group.
R _n SiO _{(4-n) / 2} (3)
(In the formula, R is the same or different unsubstituted or substituted monovalent hydrocarbon group, and n is a positive number of 1.98 to 2.02.)

  In this case, as R, alkyl group such as methyl group, ethyl group, propyl group, butyl group, cycloalkyl group such as cyclohexyl group, alkenyl group such as vinyl group, allyl group, butenyl group, hexenyl group, phenyl group, An aryl group such as a tolyl group, an aralkyl group such as a β-phenylpropyl group, or a chloromethyl group in which part or all of the hydrogen atoms bonded to carbon atoms of these groups are substituted with a halogen atom, a cyano group, or the like, trifluoro The same or different, preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon unsubstituted or substituted monovalent hydrocarbon groups selected from a propyl group, a cyanoethyl group and the like. N is a positive number of 1.98 to 2.02, and this organopolysiloxane has molecular chain ends blocked with a trimethylsilyl group, a dimethylvinylsilyl group, a dimethylhydroxysilyl group, a trivinylsilyl group, or the like. In the present invention, the organopolysiloxane must have at least two alkenyl groups in one molecule, and 0.001 to 10 mol%, particularly 0.005 to 5 mol, of R. % Is preferably an alkenyl group, in particular a vinyl group. This alkenyl group may be bonded to a silicon atom at the end of the molecular chain, may be bonded to a silicon atom in the middle of the molecular chain, or may be bonded to both.

  The structure of this organopolysiloxane basically has a linear structure in which the main chain is composed of repeating diorganosiloxane units, and both ends of the molecular chain are blocked with triorganosiloxy groups, but partially branched. The structure may be a ring structure or a ring structure. The molecular weight is not particularly limited, and can be used from a low-viscosity liquid to a high-viscosity raw rubber-like one. It is preferable to be 20,000.

  The organic peroxide as component (b) may be any known one, and specific examples include benzoyl peroxide, paramethylbenzoyl peroxide, orthomethylbenzoyl peroxide, 2,5-dimethyl- An organic peroxide containing no chlorine atom, such as 2,5-di-t-butylperoxyhexane, t-butylperoxybenzoate, dicumyl peroxide, cumyl-t-butyl peroxide, is preferably used. For atmospheric pressure hot air vulcanization, acyl-based organic peroxides of benzoyl peroxide, paramethylbenzoyl peroxide, and orthomethylbenzoyl peroxide are preferable. These organic peroxides may be used alone or in combination of two or more.

  The amount of the organic peroxide added is preferably 0.1 to 10 parts by weight, particularly 0.3 to 5 parts by weight, based on 100 parts by weight of the organopolysiloxane of component (a). If the amount is less than 0.1 parts by mass, crosslinking may be insufficient. If the amount exceeds 10 parts by mass, there is a possibility that an improvement in the curing rate cannot be expected, which is disadvantageous in terms of cost.

  In addition to the above components, the insulating silicone rubber composition of the present invention includes, as necessary, reinforcing fillers such as fumed silica, precipitated silica, fumed titanium oxide, hydroxy group-containing organosiloxane, pulverized quartz, crystals Silica, diatomaceous earth, pearlite, alumina, calcium carbonate, zinc oxide, titanium oxide and other non-reinforcing fillers, carbon black such as acetylene black, furnace black, channel black, colorant, tear strength improver, iron oxide, oxidation Heat resistance improvers such as cerium, flame retardant improvers, acid acceptors, thermal conductivity improvers, acetylene alcohols such as ethynylcyclohexanol, siloxane-modified acetylene alcohol compounds, reaction control agents such as tetravinyltetramethylcyclotetrasiloxane For various additives, mold release agents, and fillers It is optional to add various alkoxysilanes, especially phenyl group-containing alkoxysilanes and hydrolysates thereof, diphenylsilanediol, carbon functional silane, silanol group-containing low molecular weight siloxane, etc., as powders as long as the object of the present invention is not impaired. is there. In addition, these fillers are preliminarily surfaced with various alkoxysilanes and hydrolysates thereof, diphenylsilanediol, carbon functional silane, silanol group-containing low molecular siloxane, silazanes such as hexamethyldisilazane, octamethylcyclotetrasiloxane, etc. You may use what was processed. Furthermore, various solvents such as toluene, xylene, hexane, industrial gasoline, rubber volatile oil, ethyl acetate, methyl butyl ketone, and diethyl ether may be added as appropriate for use in coating.

  The insulating silicone rubber composition of the present invention includes, for example, the components (A), (B), (C) or the components (a), (b), an antistatic agent, a hollow filler as necessary, and other components. Can be prepared by mixing according to a conventional method.

  The method for curing the insulating silicone rubber composition of the present invention may be any method as long as rolls and belts used in the fixing device can be molded. For example, various methods such as injection molding, compression molding, injection molding, calendar molding, extrusion molding, coating, and screen printing can be mentioned. The curing condition is preferably in the range of 10 to 4 hours at a temperature of 60 to 350 ° C. Adopted. Further, for the purpose of reducing the compression set of the cured product, reducing the low molecular siloxane component, or removing the decomposition product of the organic peroxide, the molding is further performed in an oven at 120 to 250 ° C. for 30 minutes. Post-curing (secondary curing) for about 70 hours may be performed.

  The volume resistivity of the cured product may be any range of insulating properties as long as it can be used for fixing rolls and fixing belts, but considering the influence on rubber properties, it is 1 GΩ · m or more, preferably 5 GΩ · m or more. . Here, the volume resistivity can be measured according to JIS K6249.

  In addition, as for the antistatic level of the cured product, after charging static electricity by corona discharge on the surface of the molded product using a static honestometer (manufactured by Sisid Electrostatic Co., Ltd.) 2 minutes or less, preferably 1 minute or less.

  The fixing roll or fixing belt of the present invention forms a cured product layer of the above insulating silicone rubber composition on a belt base material of a core metal such as stainless steel, iron, nickel, aluminum, or a heat resistant resin such as polyimide. However, in this case, the material and dimensions of the core metal and the belt can be appropriately selected according to the type of the roll and the belt. In addition, a method for molding and curing the silicone rubber composition can be appropriately selected. For example, the silicone rubber composition can be molded by a method such as injection molding, transfer molding, injection molding, or coating, and is cured by heating.

  The thickness of the silicone rubber layer is not particularly limited, but in the case of a fixing roll, it is preferably 0.2 mm to 100 mm, particularly preferably 0.5 mm to 30 mm. In the case of the fixing belt, it is preferably 0.05 mm to 2 mm, particularly preferably 0.1 mm to 1 mm.

  A fluororesin layer or a fluororubber layer may be further provided on the outer periphery of the silicone rubber layer. In this case, the fluororesin layer is formed of a fluororesin coating material, a fluororesin tube, or the like, and covers the silicone rubber layer.

  Here, examples of the fluorine resin coating material include latex of polytetrafluoroethylene resin (PTFE), Daiel latex (made by Daikin Industries, Ltd., fluorine latex), and examples of the fluorine resin tube. Commercially available products can be used, for example, polytetrafluoroethylene resin (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA), fluorinated ethylene-polypropylene copolymer resin (FEP), polyfluorinated Examples thereof include vinylidene resin (PVDF) and polyvinyl fluoride resin, and among these, PFA is particularly preferable.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. In the following examples, the average particle diameter indicates a value measured by a microtrack particle size distribution measuring apparatus (manufactured by Nikkiso Co., Ltd.) using a laser light diffraction scattering method, and the viscosity is at 25 ° C. measured by a rotary viscometer. Indicates the value. Regarding the volume resistivity in Tables 1 and 2, G, T, and M represent giga (= 10 ⁹ ), tera (= 10 ¹² ), and mega (= 10 ⁶ ), respectively.

[Example 1]
Hydrophobized fumed silica (R-manufactured by Nippon Aerosil Co., Ltd.) having 100 parts by mass of a side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 700, vinyl value 0.0094 mol / 100 g) and a BET specific surface area of 110 m ² / g. 972) 2 parts by mass and 1 part by mass of iron oxide were put in a planetary mixer and stirred for 30 minutes. Then, methylhydrogenpolysiloxane having Si—H groups at both ends and side chains as a crosslinking agent (degree of polymerization) 17, 3.8 parts by mass of Si—H amount 0.0030 mol / g), 0.05 part by mass of ethynylcyclohexanol as a reaction control agent was added, and the resulting mixture was stirred for 15 minutes to obtain a silicone rubber composition. (1).
In this silicone rubber composition (1), 0.1 part by mass of a 20 mass% adipic acid ester solution of LiN (SO ₂ CF ₃ ) ₂ as an antistatic agent, 0.1 part by mass of a platinum catalyst (Pt concentration 1 mass%) After being cured at 120 ° C. for 10 minutes, post-curing was performed at 200 ° C. for 4 hours, and the rubber density, hardness, compression set, volume resistivity, and charge amount were measured by the following methods.

Rubber density, hardness and compression set were measured according to JIS K6249. The compression set was measured at 25% compression and 180 ° C. × 22 hours.
Volume resistivity measurement Measured based on JIS K6249.
Using a static amount meter (Static Static Electricity Co., Ltd.), the surface of the molded product was charged with static electricity by corona discharge, and then the time during which the charged voltage was halved was measured.

[Example 2]
Side chain vinyl group-containing dimethylpolysiloxane (degree of polymerization 700, vinyl number 0.0094 mol / 100 g) 50 parts by mass, dimethylpolysiloxane (degree of polymerization 500) having both ends blocked with dimethylvinylsiloxy groups, average particle 30 parts by mass of quartz powder with a diameter of 1.5 μm, 100 parts by mass of alumina with an average particle diameter of 12 μm, and 0.5 parts by mass of cerium oxide were put into a planetary mixer and stirred for 30 minutes, then passed once through three rolls. did. Furthermore, 3.5 parts by mass of methyl hydrogen polysiloxane of Example 1 (degree of polymerization 17, Si—H amount 0.0030 mol / g) as a crosslinking agent and 0.05 parts by mass of ethynylcyclohexanol as a reaction control agent Was added, and stirring was continued for 15 minutes to obtain a silicone rubber composition (2).
In this silicone rubber composition (2), 0.05 parts by mass of 20% adipic acid ester solution of LiN (SO ₂ CF ₃ ) ₂ as an antistatic agent, 0.1 parts by mass of platinum catalyst (Pt concentration 1% by mass) Were mixed and cured in the same manner as in Example 1, and the rubber density, hardness, compression set, volume resistivity, and charge amount were measured.

[Example 3]
Composed of 99.825 mol% of dimethylsiloxane units, 0.15 mol% of methylvinylsiloxane units, 0.025 mol% of dimethylvinylsiloxane units, 100 parts by mass of organopolysiloxane having an average degree of polymerization of about 6000, 200 m BET specific surface area ² / g of silica (trade name: Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.), 30 parts by mass, dimethylpolysiloxane having a silanol group at both ends as a dispersant, an average degree of polymerization of 15 and a viscosity at 25 ° C. of 30 cs Part was added, kneaded with a kneader, and heat-treated at 170 ° C. for 2 hours to prepare a silicone rubber composition (3).
To this silicone rubber composition (3), 0.2 parts by mass of a 20% by weight adipic acid ester solution of LiN (SO ₂ CF ₃ ) ₂ as an antistatic agent and 2,5-dimethyl-2,5-bis as a crosslinking agent After adding 0.4 parts by mass of (t-butylperoxy) hexane and mixing uniformly, press cure for 10 minutes under the conditions of 165 ° C. and 70 kgf / cm ² , and then post cure in an oven at 200 ° C. for 4 hours. Carried out. Thereafter, in the same manner as in Example 1, the rubber density, hardness, compression set, volume resistivity, and charge amount were measured.

[Example 4]
Side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 300, vinyl value 0.0074 mol / 100 g) 40 parts by mass, both side ends blocked with dimethylvinylsiloxy groups, side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 500, vinyl No. 0.0115 mol / 100g) Fumed silica (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) having 40 parts by weight, 50 parts by weight of trimethylsiloxy group-blocked dimethylpolysiloxane (polymerization degree 500), and a BET specific surface area of 200 m ² / g 25 parts by mass of glass hollow filler (Cell Star Z-36, manufactured by Tokai Kogyo Co., Ltd.) having 0.5 parts by mass, specific gravity of 0.35 and average particle size of 56 μm was put into a planetary mixer and stirred for 30 minutes. As methyl hydrogen polysiloxane (degree of polymerization 45, Si-H amount 0.004 The composition obtained by adding 2.6 parts by mass of 5 mol / g) and 0.05 parts by mass of ethynylcyclohexanol as a reaction control agent and stirring the mixture for 15 minutes was used as a silicone rubber composition (4).
In this silicone rubber composition (4), 0.05 parts by mass of a 20 mass% adipic acid ester solution of LiN (SO ₂ CF ₃ ) ₂ as an antistatic agent, 0.1 parts by mass of a platinum catalyst (Pt concentration 1 mass%) Were mixed and cured in the same manner as in Example 1, and the rubber density, hardness, compression set, volume resistivity, and charge amount were measured.

[Example 5]
70 parts by mass of side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 700, vinyl value 0.0094 mol / 100 g), 30 parts by mass of dimethylpolysiloxane (polymerization degree 250) blocked at both ends with dimethylvinylsiloxy groups, BET ratio 5 parts by mass of hydrophobized fumed silica (R-972 manufactured by Nippon Aerosil Co., Ltd.) having a surface area of 110 m ² / g, 3 parts by mass of a hollow filler made of thermoplastic resin having a specific gravity of 0.02 and an average particle size of 90 μm, and 1 part by mass of a thermoplastic resin hollow filler having a specific gravity of 0.04 and an average particle size of 50 μm was put in a planetary mixer and stirred for 30 minutes. Further, the methyl hydrogen polysiloxane of Example 4 (degree of polymerization) was used as a crosslinking agent. 45, Si-H amount 0.0045 mol / g) 3.5 parts by mass, as a reaction control agent, hexavinyldisiloxane .3 parts by mass of the composition resulting and the stirring was continued for 15 minutes and the silicone rubber composition (5).
In this silicone rubber composition (5), 0.05 parts by mass of a 20 mass% adipic acid ester solution of LiN (SO ₂ CF ₃ ) ₂ as an antistatic agent, 0.1 parts by mass of a platinum catalyst (Pt concentration 1 mass%) Were mixed and cured in the same manner as in Example 1, and the rubber density, hardness, compression set, volume resistivity, and charge amount were measured.

[Comparative Example 1]
The silicone rubber composition (1) of Example 1 was produced by the same method as in Example 1 except that no antistatic agent was added, and the rubber density, hardness, compression set, volume resistivity, and charge amount were measured. .

[Comparative Example 2]
Except for blending 15 parts by mass of a 20 mass% adipic acid ester solution of LiN (SO ₂ CF ₃ ) ₂ as an antistatic agent in the silicone rubber composition (1) of Example 1, the same method as in Example 1 was used. The rubber density, hardness, compression set, volume resistivity, and charge amount were measured.

[Comparative Example 3]
The silicone rubber composition (3) of Example 3 was produced by the same method as in Example 3 except that no antistatic agent was added, and the rubber density, hardness, compression set, volume resistivity, and charge amount were measured. .

[Comparative Example 4]
Side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 300, vinyl value 0.0074 mol / 100 g) 40 parts by mass, both side ends blocked with dimethylvinylsiloxy groups, side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 500, vinyl No. 0.0115 mol / 100g) Fumed silica (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) having 40 parts by weight, 50 parts by weight of trimethylsiloxy group-blocked dimethylpolysiloxane (polymerization degree 500), and a BET specific surface area of 200 m ² / g 0.5 parts by mass, specific gravity 0.35, glass hollow filler (Cell Star Z-36 manufactured by Tokai Kogyo Co., Ltd.) with an average particle size of 56 μm, and 4 parts by mass of carbon black are placed in a planetary mixer and stirring is continued for 30 minutes. In addition, methyl hydrogen polysiloxane (degree of polymerization) 45, Si-H amount 0.0045 mol / g), 3.5 parts by mass of ethynylcyclohexanol as a reaction control agent and 0.05 parts by mass of stirring were continued for 15 minutes to obtain a silicone rubber composition. (6).
This silicone rubber composition (6) was mixed with 0.1 part by mass of a platinum catalyst (Pt concentration 1% by mass), cured in the same manner as in Example 1, and rubber density, hardness, compression set, volume resistivity. The amount of charge was measured.

  The results of Examples 1 to 5 are shown in Table 1, and the results of Comparative Examples 1 to 4 are shown in Table 2.

[Example 6]
Primer No. for addition reaction type liquid silicone rubber on the surface of an aluminum shaft having a diameter of 30 mm and a length of 300 mm. 101 A / B (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied. The composition of Example 1 was filled between a 50 μm fluorine PFA tube primer-treated on the inner surface and an aluminum shaft, heated and cured at 120 ° C. for 30 minutes, and further post-cured at 200 ° C. for 4 hours to obtain a rubber thickness. A PFA resin-coated silicone rubber roll having a length of 2 mm and a length of 250 mm was produced.
When this roll was incorporated as a fixing roll of a laser printer and paper was passed, there was no problem such as paper entrainment even when 100 sheets were passed continuously.

[Example 7]
On the outer peripheral surface of a polyimide belt base material (thickness 50 μm, shape: inner diameter φ55 mm, width 250 mm), an addition reaction type liquid silicone rubber primer No. A 1: 1 mixture of 4 (manufactured by Shin-Etsu Chemical Co., Ltd.) and primer C (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied and dried at room temperature for 1 hour. On this, the composition of Example 2 was coated (thickness: about 300 μm), heated at 150 ° C. for 15 minutes, and further post-cured at 200 ° C. for 2 hours. Dairy latex and silicone rubber primer GLP-103SR (manufactured by Daikin) are uniformly applied to the surface of the cured product, heated at 80 ° C. for 10 minutes, and further, Daiel latex GLS-213 is applied by spraying. And heated and baked at 320 ° C. for 1 hour to prepare a fixing belt made of fluororesin-coated silicone rubber.
The fixing belt was attached to an electrophotographic copying machine and 500 A4 size copying papers were continuously copied. However, all the copied images were clear and there were no problems such as paper entrainment.

[Example 8]
Primer No. for addition reaction type liquid silicone rubber on the surface of an aluminum shaft having a diameter of 50 mm and a length of 300 mm. 101 A / B (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied. Further, the composition of Example 4 was applied thereon, cured by heating at 130 ° C. for 30 minutes, and further post-cured at 180 ° C. for 2 hours. Dairy latex and silicone rubber primer GLP-103SR (manufactured by Daikin) are uniformly applied to the surface of the cured product, heated at 80 ° C. for 10 minutes, and further, Daiel latex GLS-213 is applied by spraying. , Apply Daiel latex and silicone rubber primer GLP-103SR (manufactured by Daikin) uniformly on the surface of the cured product, heat at 80 ° C. for 10 minutes, and then apply Daiel latex GLS-213 uniformly. Then, it was heated and fired at 300 ° C. for 1 hour to prepare a Daiel latex-coated silicone rubber roll having a rubber thickness of 1 mm and a length of 250 mm.
When this roll was incorporated as a fixing roll of a laser printer and paper was passed, there was no problem such as paper entrainment even when 100 sheets were passed continuously.

[Comparative Example 5]
In Example 6, in place of the composition of Example 1, the silicone rubber composition to which no antistatic agent of Comparative Example 1 was added was used, and similarly incorporated as a fixing roll, the image was somewhat distorted from the 51st sheet. The paper was caught in the roll at the 78th sheet and stopped.

[Comparative Example 6]
In Example 8, the composition of Comparative Example 5 was used in place of the composition of Example 4, and similarly incorporated as a fixing roll, the paper was caught in the roll at the 86th sheet and stopped.

Claims (11)

  An antistatic agent is added in an amount of 0.001 to 100 parts by mass of an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule and a curing effective amount of a curing agent for curing the organopolysiloxane. An insulating silicone rubber composition for fixing rolls or fixing belts containing 2 parts by mass.   The insulating silicone rubber composition for a fixing roll or fixing belt according to claim 1, further comprising 0.1 to 100 parts by mass of a hollow filler having an average particle diameter of 200 µm or less.   The insulating silicone rubber composition for fixing rolls or fixing belts according to claim 1 or 2, wherein the antistatic agent is a lithium salt. Antistatic agents are LiBF ₄ , LiClO ₄ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiSO ₃ CF ₃ , LiN (SO ₂ CF ₃ ) ₂ , LiSO ₃ C ₄ F ₉ , LiC (SO ₂ CF ₃ ) ₃ , And an insulating silicone rubber composition for a fixing roll or a fixing belt according to claim 3, wherein the insulating silicone rubber composition is one or more selected from LiB (C ₆ H ₅ ) ₄ .   The insulating silicone rubber composition for a fixing roll or fixing belt according to any one of claims 1 to 4, wherein the silicone rubber composition is an addition-curable silicone rubber composition.   The insulating silicone rubber composition for a fixing roll or fixing belt according to any one of claims 1 to 4, wherein the silicone rubber composition is an organic peroxide curable silicone rubber composition.   The insulating silicone rubber composition for a fixing roll or fixing belt according to any one of claims 1 to 6, wherein the volume resistivity of the cured product is 1 GΩ · m or more.   A fixing roll having a silicone rubber layer formed on the outer peripheral surface of a roll shaft, wherein the silicone rubber forming the silicone rubber layer is the insulating silicone rubber composition according to any one of claims 1 to 7. A fixing roll characterized by being cured.   8. A fixing roll in which a fluororesin layer or a fluororubber layer is formed on the outer peripheral surface of a roll shaft via a silicone rubber layer, and the silicone rubber forming the silicone rubber layer is any one of claims 1 to 7. A fixing roll obtained by curing the insulating silicone rubber composition described in 1.   A fixing belt having a silicone rubber layer formed on a belt base material, wherein the silicone rubber forming the silicone rubber layer cures the insulating silicone rubber composition according to any one of claims 1 to 7. A fixing belt characterized in that the fixing belt is formed. A fixing belt in which a fluororesin layer or a fluororubber layer is formed on a belt base material via a silicone rubber layer, and the silicone rubber forming the silicone rubber layer is any one of claims 1 to 7. A fixing belt obtained by curing the insulating silicone rubber composition described above.