JP4645802B2 - Fluorine resin-coated fixing belt - Google Patents

Description

The present invention is a copying machine, a printer, relates fluororesin to be Kutsugaejo wearing belt with a cured product of the fluorine-based resin to be Kutsugaejo deposition belt high thermal conductive silicone rubber composition for use in facsimiles, particularly, high fever Silicone rubber layer that is a cured product of an addition-curing liquid silicone rubber composition that has conductivity and is excellent in adhesion to a fluororesin that is a surface layer, and has little decrease in adhesion even in roll durability at high temperatures. the related fluororesin to be Kutsugaejo wearing belt provided between the outer peripheral surface of the surface layer and the base plate made of a fluororesin.

  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 types, and the core metal is covered with silicone rubber. In addition, a type in which a fluorine resin is further coated is used. On the other hand, in order to shorten the waiting time until the temperature rises and to make the printer more compact, the thickness of the rubber layer is becoming thinner. A fixing belt type is also used in which a thinner metal or heat-resistant resin is formed into an endless belt shape and a rubber layer or a release layer is covered.

  On the other hand, when a rubber material is used for a fixing roll or a fixing belt, it is required to have high thermal conductivity in order to shorten the waiting time when starting the machine or from the viewpoint of energy saving of the machine itself. Particularly recently, the rubber layer of the fixing roll has become thinner from the viewpoint of not only thermal conductivity but also miniaturization of the apparatus and energy saving. On the other hand, instead of the roll, a fixing belt having a thinner rubber layer has begun to be used.

  However, since silicone rubber does not have high thermal conductivity of the base rubber itself, a method of adding a filler having thermal conductivity has been generally performed in order to impart high thermal conductivity. Various proposals have been made for the liquid silicone rubber composition imparted with heat conductivity as a silicone rubber for a fixing roll to which such a filler is added. In particular, alumina is mixed into the liquid silicone rubber. It has been used favorably as a thermal conductivity imparting material because it is easy and can be formulated in large quantities. However, when a large amount of alumina is blended, the heat resistance of the silicone rubber decreases, and particularly in a fixing roll or fixing belt coated with a fluororesin, the adhesive strength decreases during use, and the resin peels off. There was a problem that.

  As a technique using a silicone rubber blended with alumina in a fluororesin-coated fixing roll material, there are JP-A-11-158383 (Patent Document 1) and JP-A-2002-72728 (Patent Document 2). However, they all specify the particle size and purity of the alumina to be filled, and the heat resistance imparting agent is not specific because it is only described that it may be optionally added, and is not specified in the examples. . Furthermore, there is no description about the adhesion to the surface layer. Japanese Patent Laid-Open No. 10-39666 (Patent Document 3) discloses a roller for a fixing device in which alumina is added to an addition-curing silicone rubber, and Bengala is added as a colorant in Examples. However, this roller is a silicone rubber single layer roll having no fluororesin surface layer, and there is no description of adhesion to the surface layer, and no mention is made of the particle size of Bengala.

JP-A-11-158383 JP 2002-72728 A JP-A-10-39666

The present invention has been made in view of the above circumstances, is excellent in thermal conductivity, heat resistance is good, a fluorine-based resin to be Kutsugaejo deposition belt is particularly good adhesion durability between the surface layer of fluororesin and to provide a fluorine-based resin to be Kutsugaejo wearing belt of the cured product is provided as an intermediate elastic layer of the liquid addition curing type silicone rubber composition.

As a result of intensive studies to achieve the above object, the present inventor,
(A) An alkenyl group bonded to at least two silicon atoms is contained in one molecule, and the content of the alkenyl group is 1.0 × 10 ^{−6 to} 5.0 × 10 ⁻³ mol in the organopolysiloxane. a / g, a liquid organopolysiloxane having a viscosity at 25 ° C. or less 100,000 mPa · s: 100 parts by weight,
(B) Liquid organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule and having a viscosity at 25 ° C. of 1,000 mPa · s or less: Alkenyl group in component (A) The amount by which the molar ratio of hydrogen atoms directly bonded to silicon atoms is 0.4 to 5,
(C) Alumina having an average particle size of 0.5 to 30 μm : 50 to 1,000 parts by mass,
(D) Crystalline silica having an average particle size of 0.5 to 30 μm : 0 to 500 parts by mass,
(E) Iron oxide having an average particle size of 0.01 to 0.3 μm: 0.5 to 30 parts by mass,
(F) Addition reaction catalyst: When a cured product of a liquid addition-curable silicone rubber composition containing a catalytic amount is used as an intermediate elastic layer of a fluororesin-coated fixing belt, it has excellent heat resistance, particularly in roll durability. The present inventors have found that it exhibits good adhesiveness with a surface layer material of a fluorine-based resin, and has reached the present invention.

Accordingly, the present invention provides the following fluororesin-coated fixing belt.
[1] A fixing belt in which a fluorine-based resin layer is formed on the outer peripheral surface of a substrate made of a heat-resistant resin or metal via a silicone rubber layer, and the silicone rubber forming the silicone rubber layer includes:
(A) An alkenyl group bonded to at least two silicon atoms is contained in one molecule, and the content of the alkenyl group is 1.0 × 10 ^{−6 to} 5.0 × 10 ⁻³ mol in the organopolysiloxane. a / g, a liquid organopolysiloxane having a viscosity at 25 ° C. or less 100,000 mPa · s: 100 parts by weight,
(B) Liquid organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule and having a viscosity at 25 ° C. of 1,000 mPa · s or less: Alkenyl group in component (A) The amount by which the molar ratio of hydrogen atoms directly bonded to silicon atoms is 0.4 to 5,
(C) Alumina having an average particle size of 0.5 to 30 μm : 50 to 1,000 parts by mass,
(D) Crystalline silica having an average particle size of 0.5 to 30 μm : 0 to 500 parts by mass,
(E) Iron oxide having an average particle size of 0.01 to 0.3 μm: 0.5 to 30 parts by mass,
(F) Addition reaction catalyst: A fluororesin-coated fixing belt obtained by curing a liquid addition-curable silicone rubber composition containing a catalyst amount.

According to the present invention is excellent in thermal conductivity, heat resistance is good, a fluorine-based resin to be Kutsugaejo deposition belt, particularly adhesion durability between the surface layer of fluororesin is provided a silicone rubber intermediate elastic layer is good Is obtained.

The liquid addition-curable silicone rubber composition for a fluororesin-coated fixing belt of the present invention contains the following components (A) to (F).
(A) An alkenyl group bonded to at least two silicon atoms is contained in one molecule, and the content of the alkenyl group is 1.0 × 10 ^{−6 to} 5.0 × 10 ⁻³ mol in the organopolysiloxane. / G, a liquid organopolysiloxane (B) whose viscosity at 25 ° C. is 100,000 mPa · s or less contains at least two hydrogen atoms bonded to silicon atoms, and the viscosity at 25 ° C. Liquid organohydrogenpolysiloxane (C) having an average particle diameter of 0.5 to 30 μm and crystalline silica (E) average particles having an average particle diameter of 0.5 to 30 μm Iron oxide (F) addition reaction catalyst having a diameter of 0.01 to 0.3 μm

  In the present invention, the liquid organopolysiloxane of component (A) has an alkenyl group bonded to at least two silicon atoms in one molecule, and has a viscosity at 25 ° C. of 100,000 mPa · s or less. .

  Here, the viscosity of the liquid organopolysiloxane at 25 ° C. is 100,000 mPa · s or less, preferably 100 to 50,000 mPa · s. When the viscosity at 25 ° C. is larger than 100,000 mPa · s, it becomes difficult to mix the filler, and the moldability is also adversely affected. The viscosity can be measured with a rotational viscometer such as BS type or BH type.

Examples of the organopolysiloxane include the following average composition formula (1):
R _a SiO _{(4-a) / 2} (1)
(In the formula, R 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.)
And R has at least two alkenyl groups (preferably 2 to 8 carbon atoms, particularly preferably 2 to 6 carbon atoms) in one molecule. Examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, a hexenyl group, a cyclohexenyl group, and an octenyl group, and a vinyl group is particularly preferable.

The content of the alkenyl group is an organopolysiloxane in ^{1.0 × 10 -6 ~5.0 × 10 -3} mol / g, 5.0 × 10 -6 ~1.0 × 10 -3 It is preferably mol / g. If the alkenyl group content is less than 1.0 × 10 ⁻⁶ mol / g, the crosslinking may be insufficient and gelation may occur, and if it exceeds 5.0 × 10 ⁻³ mol / g, the crosslinking density May become too high and become brittle rubber. The 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.

  On the other hand, among the unsubstituted or substituted monovalent hydrocarbon groups represented by R, those other than alkenyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl. Group, neopentyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, alkyl group such as decyl group, aryl group such as phenyl group, tolyl group, xylyl group, naphthyl group, benzyl group, phenylethyl group, phenylpropyl group Aralkyl groups such as those described above, or those in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, bromine and chlorine, cyano groups, etc., such as chloromethyl group, chloropropyl group, bromoethyl group, Examples include a fluoropropyl group and a cyanoethyl group. In addition, it is preferable that 90% or more of all R is a methyl group.

  In addition, the structure of the organopolysiloxane is basically a linear diorganopolysiloxane in which the main chain is composed of repeating diorganosiloxane units and both ends of the molecular chain are blocked with triorganosiloxy groups. However, a partially branched structure or a cyclic structure may be used. The number of silicon atoms in one molecule (or the degree of polymerization) is preferably 50 to 1,200, particularly about 100 to 800 at room temperature (25 ° C.).

  The liquid organohydrogenpolysiloxane of component (B) contains at least two hydrogen atoms (Si-H groups) that are bonded to silicon atoms in one molecule, preferably 3 or more, and has a viscosity of 1 at 25 ° C. , 000 mPa · s or less. This organohydrogenpolysiloxane cures the composition by crosslinking the Si-H group in the molecule and the alkenyl group bonded to the silicon atom of the organopolysiloxane in the component (A) by a hydrosilylation reaction. It acts as a curing agent.

  Here, the liquid organohydrogenpolysiloxane has a viscosity at 25 ° C. of 1,000 mPa · s or less, usually 0.1 to 1,000 mPa · s, preferably 0.5 to 500 mPa · s. When the viscosity at 25 ° C. is larger than 1,000 mPa · s, it is difficult to produce the organohydrogenpolysiloxane itself.

As the organohydrogenpolysiloxane of the component (B), for example, the following average composition formula (2)
R ′ _b H _c SiO _{{4- (b + c)} / 2} (2)
Wherein R ′ 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, and b and c are b = 0.7 to 2. 1, preferably 0.8 to 2.0, c = 0.001 to 1.0, preferably 0.01 to 1.0, and b + c = 0.8 to 3.0, preferably 1.0 to 2. A positive number satisfying .5.)
And having at least 2, preferably 3 or more (usually 3 to 300), more preferably 3 to 100 silicon atoms bonded to 3 to 100 silicon atoms in one molecule Is mentioned.

  Here, examples of the unsubstituted or substituted monovalent hydrocarbon group represented by R ′ include the same groups as those exemplified as R in the above average composition formula (1), but they do not have an aliphatic unsaturated group. Those are preferred. The molecular structure of the organohydrogenpolysiloxane may be any of linear, cyclic, branched, three-dimensional network, etc. The number of silicon atoms in one molecule (or the degree of polymerization) is A liquid form is suitably used at room temperature (25 ° C.) of 2 to 300 pieces, particularly about 4 to 150 pieces. 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.

More specifically, as such an organohydrogenpolysiloxane, 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, trimethylsiloxy group-capped methylhydroterminated at both terminals Genpolysiloxane, Trimethylsiloxy group-capped dimethylsiloxane / methylhydrogensiloxane copolymer, both ends dimethylhydrogensiloxy group-capped dimethylpolysiloxane, both ends dimethylhydrogensiloxy group-capped dimethylsiloxane / methylhydrogensiloxane copolymer Combined, trimethylsiloxy group-blocked methylhydrogensiloxane / diphenylsiloxane copolymer, both ends trimethylsiloxy group-blocked methylhydrogensiloxane / diphenylsiloxane / dimethyl Le copolymer, (CH _{3) 2} HSiO _1/2 units and copolymers comprising SiO _4/2 units, (CH _{3) 2} HSiO _1/2 units and (CH _{3) 3} SiO _1/2 units copolymers comprising SiO _4/2 units, and copolymers consisting of (CH _{3) 2} HSiO _1/2 units and SiO _4/2 units and (C ₆ H ₅₎ SiO _3/2 units mentioned and It is done.

  The blending amount of the organohydrogenpolysiloxane of the component (B) is such that the molar ratio of hydrogen atoms (Si—H groups) directly bonded to silicon atoms with respect to the alkenyl groups in the component (A) is 0.4 to 0.4. The amount is 5, preferably 0.5 to 2.5. If the molar ratio is less than 0.4, curing (crosslinking) is insufficient, and a cured product having sufficient rubber elasticity cannot be obtained. If the molar ratio is more than 5, the compression set of the cured product increases.

Component (C), alumina, is in the form of fine powder, and is a component for improving the thermal conductivity of silicone rubber obtained by curing the present composition. Preferably, the average particle size of the alumina used in the present invention is 0.5-30 μm , preferably 1-20 μm. If it is less than 0.5 μm, it may be difficult to blend in a large amount in order to improve the thermal conductivity, and if it exceeds 30 μm, the adverse effect of lowering the physical properties of the rubber may increase. The shape is not particularly limited, and may be spherical or indefinite.
In the present invention, the average particle diameter can be obtained as a weight average value (or median diameter) or the like by a particle size distribution meter using an analysis means such as a laser beam diffraction method.

  Moreover, what processed the surface by organosilicon compounds, such as organoalkoxysilane, organosilazane, silanol, or alkoxy group containing organopolysiloxane, as (C) component alumina may be used. In this case, a surface-treated product may be used, or it may be added at the same time when blended with the component (A).

  (C) The compounding quantity of a component is the range of 50-1,000 mass parts with respect to 100 mass parts of (A) component, Preferably it is the range of 100-800 mass parts. If it is less than 50 parts by mass, sufficient thermal conductivity cannot be obtained, and if it exceeds 1,000 parts by mass, not only the physical properties of the rubber are remarkably deteriorated, but also blending itself is difficult.

  The crystalline silica (quartz powder) of component (D) is in the form of fine powder and improves the physical properties of silicone rubber obtained by curing this composition, and also improves the thermal conductivity in the same way as alumina. There is also an effect. In particular, when used in combination with alumina, the heat resistance of the cured silicone rubber can also be improved.

The average particle diameter of such crystalline silica is 0.5 to 30 m, preferably 1 to 20 [mu] m. If it is less than 0.5 μm, it may be difficult to mix in a large amount, and if it exceeds 30 μm, the adverse effect of lowering the rubber physical properties may be increased. The shape is not particularly limited, and may be spherical or indefinite.

  Further, as the crystalline silica of the component (D), those whose surface is treated with an organosilicon compound such as organoalkoxysilane, organosilazane, silanol, or alkoxy group-containing organopolysiloxane may be used. In this case, a surface-treated product may be used, or it may be added at the same time when blended with the component (A).

The blending amount of the component (D) is optional because it is an auxiliary component of the role of the component (C), but is in the range of 0 to 500 parts by mass with respect to 100 parts by mass of the component (A) and blended. In this case, it is usually in the range of 1 to 500 parts by mass, preferably 5 to 200 parts by mass, more preferably 10 to 200 parts by mass. When the amount exceeds 500 parts by mass, not only the physical properties of the rubber are significantly lowered, but also the blending itself is difficult.
In addition, the total amount of the component (C) and the component (D) is preferably 1,000 parts by mass or less, more preferably 800 parts by mass or less, with respect to 100 parts by mass of the component (A).

(E) The iron oxide of a component is essential in order to improve the heat resistance of the silicone rubber obtained by hardening this composition. Particularly, by combination with alumina, thereby suppressing a decrease in the heat resistance due to alumina additive, fluorine-based resin when the Fixing belt coated, the effect of improving the adhesion durability of the fluorine-based resin layer is a surface layer There is.

As such iron oxide, the average particle size is 0.01 to 0.3 μm, preferably 0.02 to 0.25 μm, more preferably 0.05 to 0.20 μm. If it is less than 0.01 μm, blending / dispersing is difficult, and if it is more than 0.3 μm, the adhesion durability effect cannot be obtained. In this case, the iron oxide is an oxide (Fe ₃ O ₄ ) containing divalent iron and trivalent iron even though it is an oxide of divalent iron (FeO) or trivalent iron (Fe ₂ O ₃ ). May be.
In addition, this average particle diameter can be measured as, for example, the cumulative weight average value D ₅₀ (or median diameter) in the particle size distribution measurement by a laser light diffraction method.

  Moreover, what processed the surface by organosilicon compounds, such as organoalkoxysilane, organosilazane, silanol, or an alkoxy-group containing organopolysiloxane, as iron oxide of (E) component may be used. In this case, a surface-treated product may be used, or it may be added at the same time when blended with the component (A).

  (E) The compounding quantity of a component is the range of 0.5-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is the range of 1-20 mass parts. If the amount is less than 0.5 parts by mass, the heat resistance and adhesion durability are not effective. If the amount exceeds 30 parts by mass, the fluidity of the rubber composition is impaired, and the physical properties of the cured rubber product are also deteriorated.

  These inorganic powders of components (C), (D), and (E) can be mixed into the composition at room temperature using equipment such as a planetary mixer or a kneader. The mixing temperature may be room temperature or under heating, but before adding the organohydrogenpolysiloxane of the component (B) and the addition reaction catalyst of the component (F) described later, a high temperature of 100 to 200 ° C. It can also be mixed below.

  Examples of the addition reaction catalyst for component (F) include platinum black, platinous chloride, chloroplatinic acid, a reaction product of chloroplatinic acid and a monohydric alcohol, a complex of chloroplatinic acid and an olefin, platinum bisacetoacetate, etc. Platinum group metal catalysts such as platinum catalysts, palladium catalysts, rhodium catalysts, and the like. The addition amount of the addition reaction catalyst is a catalyst amount, that is, an amount necessary for curing the composition. Usually, the amount of metal is 0. 0 with respect to the total mass of the component (A) and the component (B). 5 to 1,000 ppm, particularly about 1 to 500 ppm is preferable.

In the silicone rubber composition of the present invention, dry silica (fumed silica or fumed silica) can be blended as necessary. This dry silica has the effect of improving the physical properties of rubber and improving the adhesion to the surface layer made of a fluororesin. Such fumed silica, usually, the specific surface area by BET method of 50 to 400 m ² / g, in particular 100 to 350 m ² / g approximately microparticles include hydrophilic silica and hydrophobic silica.

  The dry silica content is preferably 20 parts by mass or less, more preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the component (A). If the amount exceeds 20 parts by mass, not only the fluidity of the rubber composition may be lowered, but also the compression set of the cured product may be deteriorated.

  If necessary, the silicone rubber composition includes silica filler such as wet silica (precipitated silica) and diatomaceous earth, filler such as clay, calcium carbonate and titanium dioxide, heat resistance such as cerium oxide and cerium hydroxide. Improvement agents, reaction control agents such as acetylene alcohol compounds such as ethynylcyclohexanol, vinylsiloxanes such as tetravinyltetramethylcyclotetrasiloxane, and triazole compounds such as benzotriazole, and various carbon funks to improve adhesion and moldability You may add and mix a silane, the nitrogen compound which provides a flame retardance, a halogen compound, etc.

  The silicone rubber composition of the present invention can be prepared by a known method. The silicone rubber composition thus obtained has a viscosity of 10 to 5,000 Pa · s, particularly 20 to 1,000 Pa · s at 25 ° C. measured by a rotational viscometer such as BS type and BH type. Is preferred.

  The cured product of the silicone rubber composition has a thermal conductivity of 0.4 W / m · ° C. or higher, usually 0.4 to 2.5 W / m · ° C., particularly 0.45 to 2.0 W / m · ° C. In particular, 0.5 to 1.5 W / m · ° C. is preferable. If the thermal conductivity is less than 0.4 W / m · ° C., it may not be suitable as a fixing roll depending on the type of copying machine or printer. The thermal conductivity can be usually measured with a commercially available thermal conductivity meter (for example, QTM-3 manufactured by Kyoto Electronics Co., Ltd.).

The cured product of the liquid addition-curable silicone rubber composition of the present invention, the silicone rubber layer is interposed endless belt base made of heat resistance resin or metal thin film, a fluorine-based resin coating agent or fluorine silicone rubber layer fluororesin layer due system resin tube is used as the silicone rubber layer of fluororesin to be Kutsugaejo wear belt which is formed as a surface layer. In this case, the material of the belts, the dimensions and the like may suitably selected according to the kind of the roll. Also, the molding and curing method of the silicone rubber composition can be appropriately selected. For example, the silicone rubber composition can be molded by a molding method such as injection molding, transfer molding, injection molding or coating, and the composition can be cured by heating.

  The curing conditions of the liquid addition-curable silicone rubber composition of the present invention are not particularly limited, but are cured at 100 to 180 ° C, preferably 120 to 160 ° C for 3 minutes to 1 hour, and further at 180 to 220 ° C, 1 to 12 Time post cure is preferred.

Although the thickness of the silicone rubber layer of the fluorine-based resin to be Kutsugaejo attachment belts are suitably selected, usually, 0.02～1Mm, preferably 0.05～0.8Mm.

  The fluororesin layer can be formed of a fluororesin coating material, a fluororesin tube, or the like. However, when a fluororesin coating material is used, for example, polytetrafluoroethylene resin (PTFE) latex or Daiel latex ( What is necessary is just to laminate | stack on the outer peripheral surface of the said silicone rubber layer etc. by Daikin Industries Ltd., fluorine-type latex).

Commercially available products can be used as the fluororesin tube. In this case, for example, polytetrafluoroethylene resin (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA), fluorinated ethylene-propylene copolymer. Fluorine-based resin layer by a method of filling and curing the silicone rubber composition between a substrate and the tube using a tube made of polymer resin (FEP), polyvinylidene fluoride resin (PVDF), polyvinyl fluoride resin or the like A silicone rubber layer coated with can be formed. In addition, as said fluorine-type resin layer, the thing using a PFA tube is especially preferable.

  In addition, the contact surface of the fluororesin layer and the silicone rubber layer by the fluororesin coating agent or the fluororesin tube is formed by corona discharge treatment, sodium naphthalene method, liquid ammonia method, sputter etching method, excimer laser treatment, etc. It is preferable to favor the adhesion between the silicone rubber and the fluororesin. Furthermore, primer treatment may be used to improve the adhesion durability.

  The thickness of the fluororesin layer is appropriately selected, but it is preferably 0.1 to 100 μm, particularly preferably 1 to 50 μm. If it is thinner than 0.1 μm, the hardness of the roll becomes small and the supplied paper slips. If the thickness is greater than 100 μm, the hardness of the roll increases, the nip width cannot be obtained, and the image after fixing may be defective.

EXAMPLES Hereinafter, although an Example , a reference 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, all parts are parts by mass. The specific surface area is a value measured by the BET method, and the average particle diameter is a value at 25 ° C. measured by a cumulative weight average value D ₅₀ (or median diameter) in the particle size distribution measurement by the laser light diffraction method.

[ Reference Example 1]
100 parts of dimethylpolysiloxane (polymerization degree 200) blocked at both ends with dimethylvinylsiloxy groups, and hydrophobized fumed silica having a specific surface area of 110 m ² / g as a reinforcing silica filler (manufactured by Nippon Aerosil Co., Ltd.) , R-972) 2 parts, phenyltrimethoxysilane 5 parts, 170 parts alumina with an average particle diameter of 4 μm, 3 parts iron oxide (Fe ₂ O ₃ ) with an average particle diameter of 0.10 μm in a planetary mixer, 150 Stir for 2 hours at ° C.

  After cooling, the mixture was passed through three rolls, and the filler was further dispersed, and returned to the planetary mixer. The methyl hydrogen polysiloxane having a Si—H group at both ends and side chains (polymerization degree 17, Si—H 3.2 parts of a base amount of 0.0060 mol / g), 0.05 parts of ethynylcyclohexanol and 0.1 parts of a platinum catalyst (Pt concentration 1%) are added as reaction control agents, and stirred for 15 minutes to form a silicone rubber composition A product (1) was obtained.

  Using this silicone rubber composition (1), it was press-cured at 120 ° C. for 10 minutes, and further oven-cured at 200 ° C. for 4 hours to prepare a cured silicone rubber sample, and the thermal conductivity was measured with a thermal conductivity meter QTM-3 ( As a result of measurement by Kyoto Electronics Co., Ltd., it was 0.56 W / m · ° C.

  Next, an addition reaction type liquid silicone rubber primer No. An aluminum shaft having a diameter of 10 mm and a length of 300 mm coated with the above primer on the inside of a PFA resin tube having a diameter of 15 mm, a length of 250 mm and a thickness of 50 μm coated with 101A / B (manufactured by Shin-Etsu Chemical Co., Ltd.). The silicone rubber composition (1) is placed between the tube and the shaft and fixed at a position equidistant from the inner surface of the tube. The silicone rubber composition (1) is filled between the tube and the shaft, and is heated and cured at 150 ° C. for 30 minutes. Post-curing was performed to obtain a fixing roll in which a silicone rubber layer was formed on the outer peripheral surface of the aluminum shaft, and a fluororesin layer was further formed on the outer peripheral surface of the silicone rubber layer. At this time, the thickness of the silicone rubber layer was 2.5 mm. When this fixing roll was installed in an electrophotographic copying machine and 10,000 copies of A4 size copying paper were continuously copied, an attempt was made to peel off the fluororesin layer as the surface layer, resulting in 100% rubber cohesive failure in the silicone rubber layer. It was.

で示されるシロキサン化合物８部、平均粒子径が４μｍのアルミナ１８０部、平均粒子径が１２μｍの石英粉８０部、平均粒子径０．１６μｍの酸化鉄（Ｆｅ₃Ｏ₄）６部をプラネタリーミキサーに入れ、室温（２３℃）で２時間攪拌を行った。この混合物を３本ロールにかけて充填剤の分散を行った後、再びプラネタリーミキサーに戻し、両末端及び側鎖にＳｉ−Ｈ基を有するメチルハイドロジェンポリシロキサン（重合度１７、Ｓｉ−Ｈ基量０．００６０ｍｏｌ／ｇ）を３．８部、反応制御剤としてエチニルシクロヘキサノール０．０５部、白金触媒（Ｐｔ濃度１％）０．１部を添加し、１５分撹拌を続けてシリコーンゴム組成物（２）を得た。 [Example 1 ]
Hydrophobing treatment in which 100 parts of dimethylpolysiloxane having a vinyl group in the side chain blocked at both ends with trimethylsiloxy groups (polymerization degree 300, vinyl group content 0.0072 mol / 100 g) and specific surface area 110 m ² / g Fumed silica (Nippon Aerosil Co., Ltd., R-972) 0.5 part, the following general formula (I)

A planetary mixer containing 8 parts of a siloxane compound represented by the formula: 180 parts of alumina having an average particle diameter of 4 μm, 80 parts of quartz powder having an average particle diameter of 12 μm, and 6 parts of iron oxide (Fe ₃ O ₄ ) having an average particle diameter of 0.16 μm The mixture was stirred at room temperature (23 ° C.) for 2 hours. After the mixture was spread on three rolls to disperse the filler, it was returned to the planetary mixer again, and methylhydrogenpolysiloxane having a Si—H group at both ends and side chains (polymerization degree 17, Si—H group amount). 3.8 parts of 0.0060 mol / g), 0.05 part of ethynylcyclohexanol and 0.1 part of platinum catalyst (Pt concentration 1%) as reaction control agents were added, and stirring was continued for 15 minutes to obtain a silicone rubber composition. (2) was obtained.

  Using this silicone rubber composition (2), it was press-cured at 120 ° C. for 10 minutes, and further oven-cured at 200 ° C. for 4 hours to produce a cured silicone rubber sample. The thermal conductivity was measured by a thermal conductivity meter QTM-3 ( As a result of measurement by Kyoto Electronics Co., Ltd., it was 0.71 W / m · ° C.

  Next, this silicone rubber composition (2) was applied to a polyimide resin thin film endless belt having a width of 250 mm, a circumference of 150 mm, and a thickness of 100 μm by a ring coating method to a thickness of 0.4 mm, and 30 ° C. at 30 ° C. Heat cured for minutes. Also, a polyimide resin thin film belt in which silicone rubber is laminated on a 25 μm thick PFA tube that has been primed is inserted, heated at 120 ° C. for 60 minutes, and further post-cured in an oven at 200 ° C. for 4 hours to produce a fixing belt. did. When this fixing belt was mounted on an electronic copying machine and 10,000 sheets were copied, an attempt was made to peel off the surface fluororesin layer. As a result, 100% rubber cohesive failure occurred in the silicone rubber layer.

[ Reference Example 2 ]
80 parts of dimethylpolysiloxane blocked at both ends with dimethylvinylsiloxy groups (degree of polymerization 180), 20 parts of dimethylpolysiloxane blocked at both ends with dimethylvinylsiloxy groups (degree of polymerization 400), as reinforcing silica filler 1.5 parts of fumed silica (Aerosil 200, manufactured by Nippon Aerosil Co., Ltd.) having a specific surface area of 200 m ² / g, 5 parts of propyltrimethoxysilane, 200 parts of alumina having an average particle diameter of 4 μm, and 150 of alumina having an average particle diameter of 12 μm And 2.5 parts of iron oxide (Fe ₂ O ₃ ) having an average particle diameter of 0.20 μm were put into a planetary mixer and stirred at 100 ° C. for 2 hours.

  After cooling, the mixture was passed through three rolls, and the filler was further dispersed, and returned to the planetary mixer. The methyl hydrogen polysiloxane having a Si—H group at both ends and side chains (polymerization degree 17, Si—H 2.9 parts of a base amount of 0.0060 mol / g), 0.05 part of ethynylcyclohexanol and 0.1 part of a platinum catalyst (Pt concentration 1%) as reaction control agents are added, and stirred for 15 minutes to form a silicone rubber composition A product (3) was obtained.

  Using this silicone rubber composition (3), it was press-cured at 120 ° C. for 10 minutes, and further oven-cured at 200 ° C. for 4 hours to prepare a cured silicone rubber sample, and the thermal conductivity was measured by a thermal conductivity meter QTM-3 ( As a result of measurement by Kyoto Electronics Co., Ltd., it was 0.85 W / m · ° C.

  Next, an addition reaction type liquid silicone rubber primer No. An aluminum shaft having a diameter of 10 mm and a length of 300 mm coated with the above primer on the inside of a PFA resin tube having a diameter of 13 mm, a length of 250 mm, and a thickness of 50 μm coated with 101A / B (manufactured by Shin-Etsu Chemical Co., Ltd.). The silicone rubber composition (3) is filled between the tube and the shaft, fixed at a position that is equidistant from the inner surface of the tube, heated and cured at 150 ° C. for 30 minutes, and further at 200 ° C. for 4 hours. Post-curing was performed to obtain a fixing roll in which a silicone rubber layer was formed on the outer peripheral surface of the aluminum shaft, and a fluororesin layer was further formed on the outer peripheral surface of the silicone rubber layer. At this time, the thickness of the silicone rubber layer was 2.5 mm. When this fixing roll was installed in an electrophotographic copying machine and 10,000 copies of A4 size copying paper were continuously copied, an attempt was made to peel off the fluororesin layer as the surface layer, resulting in 100% rubber cohesive failure in the silicone rubber layer. It was.

[Comparative Example 1]
The silicone rubber composition (4) of Reference Example 1 which did not contain iron oxide was designated as a silicone rubber composition (4). Using this silicone rubber composition (4), press cure at 120 ° C. for 10 minutes and further oven cure at 200 ° C. for 4 hours to prepare a cured silicone rubber sample, and the thermal conductivity is measured by a thermal conductivity meter QTM-3 ( As a result of measurement by Kyoto Electronics Co., Ltd., it was 0.55 W / m · ° C.
Using this silicone rubber composition (4), a fixing roll was prepared in the same manner as in Reference Example 1. This fixing roll was mounted on an electrophotographic copying machine, and 10,000 sheets of A4 size copying paper were continuously copied, and then the surface layer. When the fluororesin layer was peeled off, about 20% was caused by rubber cohesive failure in the silicone rubber layer, and the other about 80% was caused by interfacial peeling between the silicone rubber layer and the fluororesin layer.

[Comparative Example 2]
A silicone rubber composition obtained by changing 6 parts of iron oxide having an average particle diameter of 0.16 μm to 6 parts of iron oxide (Fe ₃ O ₄ ) having an average particle diameter of 0.35 μm in the silicone rubber composition (2) of Example 1 . (5). Using this silicone rubber composition (5), press cure at 120 ° C. for 10 minutes and then oven cure at 200 ° C. for 4 hours to prepare a cured silicone rubber sample, and the thermal conductivity is measured by a thermal conductivity meter QTM-3 ( As a result of measurement by Kyoto Electronics Co., Ltd., it was 0.71 W / m · ° C.
Using this silicone rubber composition (5), a fixing belt was produced in the same manner as in Example 1. The fixing belt was mounted on an electrophotographic copying machine, and 10,000 sheets of A4 size copying paper were continuously copied. When the fluororesin layer was peeled off, about 80% was caused by rubber cohesive failure in the silicone rubber layer, and the other about 20% was caused by interfacial peeling between the silicone rubber layer and the fluororesin layer.

[Comparative Example 3]
In the silicone rubber composition (3) of Reference Example 2 , 2.5 parts of iron oxide having an average particle diameter of 0.20 μm were changed to 2.5 parts of iron oxide (Fe ₂ O ₃ ) having an average particle diameter of 0.50 μm. A silicone rubber composition (6) was obtained. Using this silicone rubber composition (6), it was press-cured at 120 ° C. for 10 minutes, and further oven-cured at 200 ° C. for 4 hours to prepare a cured silicone rubber sample. The thermal conductivity was measured by a thermal conductivity meter QTM-3 ( As a result of measurement by Kyoto Electronics Co., Ltd., it was 0.85 W / m · ° C.
Using this silicone rubber composition (6), a fixing roll was prepared in the same manner as in Reference Example 2. The fixing roll was mounted on an electrophotographic copying machine, and 10,000 sheets of A4 size copying paper were continuously copied, and then the surface layer. When the fluororesin layer was peeled off, there was no cohesive failure, and 100% interfacial delamination occurred between the silicone rubber layer and the fluororesin layer.

Claims (6)

A fixing belt in which a fluorine-based resin layer is formed on a peripheral surface of a substrate made of a heat-resistant resin or metal via a silicone rubber layer, and the silicone rubber forming the silicone rubber layer includes:
(A) An alkenyl group bonded to at least two silicon atoms is contained in one molecule, and the content of the alkenyl group is 1.0 × 10 ^{−6 to} 5.0 × 10 ⁻³ mol in the organopolysiloxane. a / g, a liquid organopolysiloxane having a viscosity at 25 ° C. or less 100,000 mPa · s: 100 parts by weight,
(B) Liquid organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule and having a viscosity at 25 ° C. of 1,000 mPa · s or less: Alkenyl group in component (A) The amount by which the molar ratio of hydrogen atoms directly bonded to silicon atoms is 0.4 to 5,
(C) Alumina having an average particle size of 0.5 to 30 μm : 50 to 1,000 parts by mass,
(D) Crystalline silica having an average particle size of 0.5 to 30 μm : 0 to 500 parts by mass,
(E) Iron oxide having an average particle size of 0.01 to 0.3 μm: 0.5 to 30 parts by mass,
(F) Addition reaction catalyst: A fluororesin-coated fixing belt obtained by curing a liquid addition-curable silicone rubber composition containing a catalyst amount.   The fluororesin-coated fixing belt according to claim 1, wherein the cured product of the silicone rubber composition has a thermal conductivity of 0.4 W / m · ° C or higher.   The fluororesin-coated fixing belt according to claim 1 or 2, wherein the silicone rubber composition further comprises 20 parts by mass or less of dry silica with respect to 100 parts by mass of the component (A).   The fluororesin-coated fixing belt according to any one of claims 1 to 3, wherein an average particle diameter of iron oxide as the component (E) of the silicone rubber composition is 0.01 to 0.2 µm.   The fluororesin-coated fixing belt according to any one of claims 1 to 3, wherein an average particle diameter of iron oxide as the component (E) of the silicone rubber composition is 0.01 to 0.16 µm. The average particle diameter of the alumina (C) component of the silicone rubber composition is 1 to 20 μm, and the average particle diameter of the crystalline silica (D) component is 1 to 20 μm. The fluorine resin-coated fixing belt described in the item.