JP4420231B2 - Fixing roll - Google Patents

Description

  The present invention relates to a fixing roll used for a copying machine, a laser beam printer, a FAX, and the like. More specifically, the present invention relates to a fixing roll that is excellent in durability without rupture of rubber even when the nip width between the rolls is increased for high-speed printing or color printing and the temperature of the toner fixing portion is increased.

  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. In recent years, with the speeding up of copying and the spread of color copying, it is necessary to melt and fix the toner in a short time, and the fixing roll is also required to have low hardness in order to increase the nip width. However, when the hardness of the silicone rubber is lowered, the toner releasability and the rubber strength are lowered. Therefore, a method using a fluororesin for the surface layer has been adopted.

  However, recently, the speed has further increased, and the hardness of the rubber layer has further decreased, and the temperature of the fixing portion has increased. When silicone rubber is present between the surface fluororesin and the core metal, that is, when subjected to high heat and repeated compression for a long time in a sealed state, the silicone rubber softens and deteriorates, resulting in rubber destruction. . In order to prevent such deterioration, there is a method of increasing the crosslinking density of the silicone rubber, but the rubber becomes hard and the nip width cannot be sufficiently obtained. Various methods for increasing the thermal conductivity of silicone rubber are also known in order to efficiently transfer the heat of the core metal to the toner so as not to raise the core metal temperature (Patent Document 1: Japanese Patent Laid-Open No. 10-39666). Patent Document 2: JP-A-11-158377) requires a large amount of inorganic filler to be added in order to increase the thermal conductivity of the silicone rubber, which increases the rubber hardness. The nip width cannot be removed. Alternatively, there is a method in which the rubber layer is thinned and heat is efficiently transferred to the surface layer. In this case as well, not only a sufficient nip width is obtained, but if the rubber elasticity is insufficient, the sharpness of the image is lowered.

  Furthermore, about a roll, there exists a proposal in Unexamined-Japanese-Patent No. 4-173328 (patent document 3) and Unexamined-Japanese-Patent No. 2002-304075 (patent document 4).

JP-A-10-39666 Japanese Patent Laid-Open No. 11-158377 JP-A-4-173328 JP 2002-304075 A

  The present invention has been made in view of the above circumstances, and provides a highly durable fixing roll in which the nip width between the rolls is increased, and even when the temperature of the toner fixing portion is increased, the silicone rubber layer is less susceptible to rubber breakage. The purpose is to do.

  As a result of intensive studies to achieve the above object, the present inventors have found that a silicone rubber layer in a fixing roll having an elastic layer made of silicone rubber around a conventional metal core and a surface layer made of a fluororesin around the elastic layer. By using two types of rubber with different hardness, that is, a silicone rubber having higher hardness than the second silicone rubber layer (outer layer) close to the surface layer as the first silicone rubber layer (inner layer) close to the core metal In particular, the present invention has been found to be suitable as a fixing roll for color and high-speed type copying machines and laser beam printers.

  In addition, about the roll which made such silicone rubber into two layers, although the method of providing a silicone rubber adhesive layer as an outer layer is shown by Unexamined-Japanese-Patent No. 4-173328, there is no specific illustration of hardness, Further, in the detailed description of the invention, the outer adhesive layer is “preferably equal to or higher by about 10” than the hardness of the inner silicone rubber layer, which is completely different from the present invention. Japanese Patent Application Laid-Open No. 2002-304075 exemplifies a method in which the inner layer is a phenyl group-containing silicone rubber, and in the examples, there is a description of the hardness of the roll. There is no description. Further, the present invention is completely different from the present invention in that the surface layer does not have a fluororesin.

Accordingly, the present invention provides the following fixing roll.
Claim 1:
A first silicone rubber layer (inner layer) is provided on the outer periphery of the roll shaft, a second silicone rubber layer (outer layer) is provided on the outer side of the first silicone rubber layer, and a surface layer made of a fluororesin is further provided on the outer side. In the fixing roll having a silicone rubber inner layer and an outer layer,
(A) 100 parts by mass of an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule ;
(B) 0.1 to 50 parts by mass of an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to at least a silicon atom in one molecule ;
(C) 0 to 1,000 parts by mass of an inorganic filler ,
(D) Amount of catalyst for addition reaction catalyst
And a molar ratio of the total amount of silicon-bonded hydrogen atoms of the component (B) to the alkenyl groups bonded to the silicon atoms of the component (A). A fixing roll having a silicone rubber inner layer of 0.5 to 2.0 and a silicone rubber outer layer of 0.3 to 1.5, wherein the silicone rubber inner layer is harder than the silicone rubber outer layer.
Claim 2:
The hardness of the silicone rubber inner layer by durometer A is 2 or more and 30 or less, the hardness of the silicone rubber outer layer is 15 or less, and the rubber hardness of the silicone rubber outer layer is 2 points or more lower than the rubber hardness of the silicone rubber inner layer. The fixing roll described.
Claim 3:
The thickness of the silicone rubber inner layer is 0.1 to 10 mm, the thickness of the silicone rubber outer layer is 0.3 to 30 mm, and the thickness of the silicone rubber inner layer is 2/3 or less of the thickness of the silicone rubber outer layer. The fixing roll according to claim 1 or 2, characterized in that
Claim 4 :
The fixing roll according to any one of claims 1 to 3 , wherein the inner layer and the outer layer of the silicone rubber are each formed of dimethyl silicone rubber.
Claim 5 :
The fixing roll is characterized in that the roll shaft (core metal) temperature during operation is 230 ° C. or higher, the temperature of the roll surface is 180 ° C. or higher, and the temperature difference between the core metal temperature and the roll surface is 30 ° C. or higher. The fixing roll according to any one of claims 1 to 4 .
Claim 6 :
Fixing roll, fuser roll of any one of claims 1-5, characterized in that a roll having a heat source therein metal core.
According to claim 7:
Fixing roll, the roll rotation speed during operation, A4 copies feeding speed for monochrome printing is 30 sheets / min or more, more of claims 1-6, characterized in that when it is 10 sheets / min or more color printing The fixing roll according to claim 1.

  The fixing roll of the present invention is excellent in durability because the nip width between the rolls is large and the temperature of the toner fixing portion is high, so that the silicone rubber layer is hardly damaged by rubber.

The fixing roll of the present invention has a first silicone rubber layer (inner layer) on the outer periphery of the roll shaft, and has a second silicone rubber layer (outer layer) outside the first silicone rubber layer. A fixing roll having a surface layer made of a fluororesin on the outside, wherein the inner layer silicone rubber has a higher hardness than the outer layer silicone rubber.
Such a fixing roll has very high durability without rubber breakage for a long time even when used at high temperature and high speed.

  In particular, the hardness of the silicone rubber inner layer by durometer A is 2 or more and 30 or less, preferably 2 or more and 25 or less, and more preferably 3 or more and 20 or less. If the hardness exceeds 30, the hardness may be too high to obtain a sufficient nip width necessary for toner fixing, and if it is less than 1, the rubber may be destroyed in a short time due to high heat. On the other hand, the hardness of the silicone rubber outer layer by durometer A is 15 or less, preferably 12 or less, more preferably 10 or less. If the hardness exceeds 15, the required nip width may not be obtained. In addition, although the minimum of the hardness of an outer layer is selected suitably, it is preferable that it is usually 0 or more, especially 1 or more, especially 2 or more.

  The rubber hardness of the outer layer must be lower than the rubber hardness of the inner layer, preferably 2 points or more, more preferably 3 points or more, particularly preferably 5 points or more in terms of durometer A hardness. This is because if the inner layer rubber hardness is lower than the outer layer rubber hardness, the inner layer rubber tends to break down due to softening deterioration due to heat and repeated compression, and the outer layer rubber is hard and the nip width becomes insufficient. It is because it ends. In this case, the outer layer hardness may be considerably lower than the inner layer hardness, but the outer layer is preferably 20 points or less, particularly 15 points or less lower than the inner layer.

  Moreover, it is preferable that the thickness of a silicone rubber layer is 0.1-10 mm in an inner layer, More preferably, it is 0.2-5 mm. If it is less than 0.1 mm, not only the heat resistance as a fixing roll cannot be provided sufficiently, but also molding may be difficult. If it exceeds 10 mm, a sufficient nip width may not be obtained. . Further, the thickness of the outer silicone rubber layer is preferably 0.3 to 30 mm, more preferably 0.5 to 5 mm. If it is less than 0.3 mm, the nip width may be insufficient. If it exceeds 30 mm, the heat conduction may be deteriorated, and it is economically disadvantageous. Further, the thickness of the inner layer of the silicone rubber is preferably 2/3 or less of the thickness of the outer layer, more preferably 1/2 or less. This is because if the thickness of the outer layer exceeds 2/3 of the thickness of the inner layer, the nip width may not be sufficient, and the entire rubber layer becomes thick, which is economically disadvantageous. is there.

As the silicone rubber for the inner layer and the outer layer, those obtained by curing a liquid addition-curable silicone rubber composition are preferable. In this case, it is more preferable that both the inner layer and the outer layer are dimethyl silicone rubber. In particular,
(A) 100 parts by mass of an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule;
(B) 0.1-50 parts by mass of an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to at least a silicon atom in one molecule;
(C) Inorganic filler 0 to 1,000 parts by mass,
(D) Addition reaction catalyst It is preferable that it is what hardened | cured the liquid addition-curable silicone rubber composition which uses a catalyst amount as a structural component.

  In addition, the hardness of the silicone rubber of the inner layer and the outer layer can be adjusted to a desired one depending on the types of the components (A) and (B), the use ratio thereof, the type and blending amount of the inorganic filler, and the like.

Here, as the organopolysiloxane having an alkenyl group bonded to at least two silicon atoms on average in one molecule of the component (A), those represented by the following average composition formula (1) can be used. .
R ¹ _a SiO _{(4-a) / 2} (1)

In the above formula (1), 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 Is a positive number in the range of 1.8 to 2.5, more preferably 1.95 to 2.02.

Here, as the unsubstituted or substituted monovalent hydrocarbon group bonded to the silicon atom represented by R ¹ , a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, 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 Aralkyl groups such as groups, 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. Substituted with halogen atoms such as bromine, chlorine, cyano groups, etc., such as chloromethyl group, chloropro 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). The content of alkenyl groups in the organic group R ¹ 0.005 to 20 mol%, it is particularly preferable to be 0.01 to 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. Incidentally, 90 mol% or more of R ¹ except alkenyl group (90 to 100 mole%), particularly 95 to 100 mol%, is preferably further 99 to 100 mol% are methyl groups.

  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 as long as it is liquid, but the degree of polymerization is preferably from 100 to 2,000, particularly from 150 to 1,000, in order to cure and become a rubbery elastic body. If it is less than 100, it may become a brittle rubber cured product, and if it is 2,000 or more, the viscosity may be too high and molding may be difficult.

The (B) component organohydrogenpolysiloxane reacts with the (A) component and acts as a cross-linking agent, and there is no particular limitation on its molecular structure, for example, linear, cyclic, branched, which has been conventionally produced. Various types of materials such as a shape and a three-dimensional network structure (resin-like) can be used, but a hydrogen atom (hydrosilyl group represented by SiH) bonded to two or more, preferably three or more silicon atoms in one molecule. In general, it is desirable to have about 2 to 500, preferably 3 to 200, more preferably about 3 to 150 SiH groups. As this organohydrogenpolysiloxane, those represented by the following average composition formula (2) are used.
R ² _b H _c SiO _{(4-bc) / 2} (2)

In the above formula (2), R ^2, excluding aliphatic unsaturated bond, preferably unsubstituted or substituted monovalent hydrocarbon groups bonded to the silicon atom having 1 to 10 carbon atoms, non-in the R ² Examples of the substituted or substituted monovalent hydrocarbon group include 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, a neopentyl group, a hexyl group, a cyclohexyl group, and an octyl group. Alkyl groups such as nonyl group and decyl group, aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group, aralkyl groups such as benzyl group, phenylethyl group and phenylpropyl group, and hydrogen atoms of these groups Some or all of them substituted with halogen atoms such as fluorine, bromine, chlorine, such as chloromethyl group, chloropropyl group, bromoethyl group, trifluoro And a ropropyl group. The unsubstituted or substituted monovalent hydrocarbon group for R ² is preferably an alkyl group or an aryl group, and more preferably a methyl group. B is 0.7 to 2.1, c is 0.001 to 1.0, and b + c is a positive number satisfying 0.8 to 3.0. Preferably, b is 1.0 to 1.0. 2.0 and c are 0.01 to 1.0, and b + c is 1.5 to 2.5.

  Two or more, preferably three or more SiH groups contained in one molecule may be located either at the end of the molecular chain or in the middle of the molecular chain, or may be located at both. The molecular structure of the organohydrogenpolysiloxane may be any of linear, cyclic, branched, and three-dimensional network structures, but the number of silicon atoms in one molecule (or the degree of polymerization) is usually 2 ˜500, preferably 3 to 300, more preferably about 3 to 150 are desirable, and the viscosity at 25 ° C. is usually 0.1 to 10,000 mPa · s, preferably 0.5 to 5, A liquid is used at room temperature (25 ° C.) of about 000 mPa · s.

Specific examples of the organohydrogenpolysiloxane of the above formula (2) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, tris (hydrogen Dimethylsiloxy) methylsilane, tris (hydrogendimethylsiloxy) phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane / dimethylsiloxane cyclic copolymer, both ends trimethylsiloxy group-blocked methylhydrogenpolysiloxane, both ends trimethylsiloxy Group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, both ends dimethylhydrogensiloxy group-blocked dimethylpolysiloxane, both ends dimethylhydrogensiloxy group-blocked dimethylsiloxa・ Methyl hydrogen siloxane copolymer, both ends trimethylsiloxy group-blocked methyl hydrogen siloxane ・ Diphenyl siloxane copolymer, both ends trimethylsiloxy group-blocked methyl hydrogen siloxane ・ Diphenyl siloxane ・ dimethyl siloxane copolymer, both ends trimethylsiloxy Blocked methylhydrogensiloxane / methylphenylsiloxane / dimethylsiloxane copolymer, both ends dimethylhydrogensiloxy group-blocked methylhydrogensiloxane / dimethylsiloxane / diphenylsiloxane copolymer, both ends dimethylhydrogensiloxy group-blocked methylhydrogen Siloxane / dimethylsiloxane / methylphenylsiloxane copolymer, (CH ₃ ) ₂ HSiO _1/2 unit and (CH ₃ ) ₃ SiO _1/2 unit Copolymers consisting of units and SiO _4/2 units, copolymers consisting of (CH ₃ ) ₂ HSiO _1/2 units and SiO _4/2 units, (CH ₃ ) ₂ HSiO _1/2 units and SiO _{4 And a} copolymer composed of _{/ 2} units and (C ₆ H ₅ ) SiO _3/2 units.

  The compounding amount of the organohydrogenpolysiloxane is preferably 0.1 to 50 parts by mass, particularly preferably 0.3 to 30 parts by mass with respect to 100 parts by mass of the organopolysiloxane as the component (A).

  In addition, this 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) is 0.3. To 2.0, particularly 0.5 to 2.0 for the inner layer, more preferably 0.7 to 1.87. On the other hand, for the outer layer, 0.3 to 1.5 is preferable, and 0.4 to 1.2 is more preferable.

  The inorganic filler of component (C) is blended for the purpose of reinforcing cured rubber, improving thermal conductivity, adjusting viscosity and rubber hardness, improving heat resistance, and coloring. Such materials include fumed silica, precipitated silica, diatomaceous earth, pulverized quartz, titanium oxide, iron oxide, cerium oxide, aluminum oxide, zinc oxide, and carbon black.

  The blending amount can be 0 to 1,000 parts by mass with respect to 100 parts by mass of the component (A), and for the purpose of reinforcement, 1 to 50 parts by mass. 1,000 parts by weight, 0.1 to 5 parts by weight for heat resistance and coloring purposes, and any other amount for viscosity and hardness adjustment purposes. However, in any case, it is 1,000 parts by mass or less, preferably 800 parts by mass or less. When it exceeds 1,000 parts by mass, not only the physical properties of the rubber are remarkably lowered but also the compounding becomes difficult. Such inorganic fillers include various alkoxysilanes and hydrolysates thereof, diphenylsilanediol, carbon functional silane, silanol group-containing low molecular siloxanes, silazanes such as hexamethyldisilazane, octamethylcyclotetrasiloxane, etc. Those surface-treated with a surface treatment agent may be used, or these surface treatment agents may be added simultaneously with the filler.

  The addition reaction catalyst for component (D) 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 catalytic quantity, 0.5-1,000 ppm with respect to the total mass of (A) component and (B) component as platinum group metal normally, especially 1 It is preferable to blend about ˜500 ppm.

  The silicone rubber composition according to the present invention may be cured by any method as long as the roll used in the fixing device can be molded. For example, there are various methods such as injection molding, compression molding, injection molding, and coating. As curing conditions, a range of 10 seconds to 4 hours at a temperature of 60 to 350 ° C. is preferably employed. Further, for the purpose of reducing the compression set of the cured product, reducing or removing the low molecular siloxane component, post-curing for about 30 minutes to 70 hours in an oven at 120 to 250 ° C. after molding (for example) A secondary cure may be performed. The two layers of silicone rubber are preferably molded by curing the inner layer by a method such as in-mold or coating, and then molding the outer-layer silicone rubber by further molding or coating. In this case, after the inner layer silicone rubber is cured, when the outer layer silicone rubber is cured, a method such as using a primer or applying an adhesive is used to more firmly bond the inner layer and outer layer silicone rubber. Also good.

  The fixing roll of the present invention forms two types of silicone rubber layers on a core metal such as stainless steel, iron, nickel, and aluminum. In this case, the material and dimensions of the core metal and the belt are the types of the roll. Can be selected as appropriate.

  The fluorine resin layer formed on the outer periphery of the silicone rubber layer is formed of a fluorine resin coating material, a fluorine resin tube, or the like. Here, examples of the fluorine resin coating material include latex of polytetrafluoroethylene resin (PTFE), Daiel latex (manufactured by Daikin Industries, Ltd., fluorine latex), and commercially available fluorine resin tubes. For example, polytetrafluoroethylene resin (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA), fluorinated ethylene-polypropylene copolymer resin (FEP), polyvinylidene fluoride resin ( PVDF), polyvinyl fluoride resin, and the like. Among these, PFA is particularly preferable.

  In addition, the fixing roll of the present invention can be used for fixing portions of any commonly used copying machines, laser printers, FAX machines, etc., but is particularly suitable for use in conditions where it has a heater inside and is exposed to high temperatures. it can. As the temperature of such a fixing portion, the temperature of the roll shaft (core metal) at the time of the toner fixing operation is preferably 230 ° C. or higher, more preferably 250 ° C. or higher, and the temperature of the roll surface is 180 ° C. It is preferable that it is more than ° C, and more preferably it is 200 ° C or more. Furthermore, when the temperature difference between the roll shaft and the roll surface is 30 ° C. or higher, more preferably 40 ° C. or higher, the fixing roll of the present invention is suitably used.

  Further, the fixing roll of the present invention is particularly suitable when the printing speed is high. In the case of monochrome, the A4 paper has a sheet feeding speed of 30 sheets / minute or more, preferably 40 sheets / minute or more. Similarly, when A4 paper is used and the paper feeding speed is 10 sheets / minute or more, preferably 15 sheets / minute or more, it is suitably used.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to a following example.

[Composition 1]
Hydrophobized fumed silica (manufactured by Nippon Aerosil Co., Ltd.) having 100 parts by mass of side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 700, vinyl value 0.0094 mol / 100 g) and specific surface area by BET method of 110 m ² / g R-972) 2 parts by mass, 1 part by mass of iron oxide, and 50 parts by mass of quartz powder having an average particle diameter of 5 μm were put into a planetary mixer and stirred for 30 minutes. SiH group-containing methyl hydrogen polysiloxane (degree of polymerization 17, SiH amount 0.0030 mol / g) 2.2 parts by mass (SiH / alkenyl = 0.7), ethynylcyclohexanol 0.05 parts by mass as a reaction control agent Then, 0.1 parts by mass of platinum catalyst (Pt concentration: 1% by mass) was added, and the resulting mixture was stirred for 15 minutes. (1), and it was.
This composition was press-cured at 120 ° C. for 10 minutes and then post-cured at 200 ° C. for 4 hours, and the rubber density, hardness, and tensile strength were measured in accordance with JIS K6249.

[Composition 2]
20 parts by mass of side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 700, vinyl value 0.0094 mol / 100 g), 80 parts by mass of dimethylpolysiloxane (polymerization degree 500) blocked at both ends with dimethylvinylsiloxy groups, average particle After 20 parts by mass of quartz powder having a diameter of 1.5 μm, 200 parts by mass of alumina having an average particle diameter of 12 μm, 1.0 part by mass of iron oxide, and 0.5 part by mass of cerium oxide are placed in a planetary mixer and stirring is continued for 30 minutes. Passed once through three rolls. Furthermore, 2.5 parts by mass (SiH / alkenyl = 1.1) of methyl hydrogen polysiloxane (degree of polymerization 17, SiH amount 0.0030 mol / g) of composition 1 as a crosslinking agent, and ethynyl as a reaction control agent A composition obtained by adding 0.05 parts by mass of cyclohexanol and 0.1 parts by mass of a platinum catalyst (Pt concentration: 1% by mass) and continuing stirring for 15 minutes was used as a silicone rubber composition (2).
This composition was press-cured at 120 ° C. for 10 minutes and then post-cured at 200 ° C. for 4 hours, and the rubber density, hardness, and tensile strength were measured in accordance with JIS K6249.

[Composition 3]
Hydrophobized fumed silica (manufactured by Nippon Aerosil Co., Ltd.) having 100 parts by mass of side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 700, vinyl value 0.0094 mol / 100 g) and specific surface area by BET method of 110 m ² / g R-972) 2 parts by mass, 1 part by mass of iron oxide, and 50 parts by mass of quartz powder having an average particle diameter of 5 μm were put into a planetary mixer and stirred for 30 minutes. SiH group-containing methyl hydrogen polysiloxane (degree of polymerization 17, SiH amount 0.0030 mol / g) 2.0 parts by mass (SiH / alkenyl = 0.52), ethynylcyclohexanol 0.05 parts by mass as a reaction control agent Then, 0.1 parts by mass of platinum catalyst (Pt concentration: 1% by mass) was added, and the resulting mixture was stirred for 15 minutes. It was the object (3).
This composition was press-cured at 120 ° C. for 10 minutes and then post-cured at 200 ° C. for 4 hours, and the rubber density, hardness, and tensile strength were measured in accordance with JIS K6249.

[Composition 4]
Hydrophobized fumed silica (manufactured by Nippon Aerosil Co., Ltd.) having 100 parts by mass of side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 700, vinyl value 0.0094 mol / 100 g) and specific surface area by BET method of 110 m ² / g R-972) 2 parts by mass, 1 part by mass of iron oxide, and 50 parts by mass of quartz powder having an average particle diameter of 5 μm were put into a planetary mixer and stirred for 30 minutes. 1.7 parts by mass (SiH / alkenyl = 0.65) of methyl hydrogen polysiloxane having a SiH group (degree of polymerization 17, SiH amount 0.0030 mol / g), 0.05 part by mass of ethynylcyclohexanol as a reaction control agent Then, 0.1 parts by mass of platinum catalyst (Pt concentration: 1% by mass) was added, and the resulting mixture was stirred for 15 minutes. It was the object (4).
This composition was press-cured at 120 ° C. for 10 minutes and then post-cured at 200 ° C. for 4 hours, and the rubber density, hardness, and tensile strength were measured in accordance with JIS K6249.

[Composition 5]
20 parts by mass of side chain vinyl group-containing dimethylpolysiloxane (polymerization degree 700, vinyl value 0.0094 mol / 100 g), 80 parts by mass of dimethylpolysiloxane (polymerization degree 500) blocked at both ends with dimethylvinylsiloxy groups, average particle After 20 parts by mass of quartz powder having a diameter of 1.5 μm, 200 parts by mass of alumina having an average particle diameter of 12 μm, 1.0 part by mass of iron oxide, and 0.5 part by mass of cerium oxide are placed in a planetary mixer and stirring is continued for 30 minutes. Passed once through three rolls. Further, 2.0 parts by mass (SiH / alkenyl = 0.9) of methylhydrogenpolysiloxane (degree of polymerization 17, SiH amount 0.0030 mol / g) of composition 1 as a crosslinking agent and ethynyl as a reaction control agent A silicone rubber composition (5) was obtained by adding 0.05 part by weight of cyclohexanol and 0.1 part by weight of a platinum catalyst (Pt concentration: 1% by weight) and continuing stirring for 15 minutes.
This composition was press-cured at 120 ° C. for 10 minutes and then post-cured at 200 ° C. for 4 hours, and the rubber density, hardness, and tensile strength were measured in accordance with JIS K6249.

  Table 1 shows the physical properties of a cured product (silicone rubber) obtained by curing the above composition.

[Example 1]
Primer No. for addition reaction type liquid silicone rubber on the surface of an aluminum shaft having a diameter of 20 mm and a length of 300 mm. 101 A / B (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied. The shaft was set at the center of the mold, and the silicone rubber composition (1) was poured into the mold and heat-cured at 140 ° C. for 20 minutes. This was taken out of the mold to obtain a roll having a thickness of 0.6 mm and a silicone rubber layer formed on the roll axis. This roll is further set at the center of a mold in which a 50 μm fluorine PFA tube whose inner surface has been primed is attached to the mold, and the silicone rubber composition (3) is injected between the roll and 120 ° C. for 30 minutes. Heat cured and removed from the mold. This was further post-cured at 200 ° C. for 4 hours to prepare a PFA resin-coated silicone rubber roll having a rubber thickness of 2.0 mm (inner layer 0.6 mm, outer layer 1.4 mm) and length of 250 mm. When this roll was incorporated as a fixing roll for a monochrome laser printer and paper was passed (45 sheets / minute, cored bar temperature 260 ° C., surface layer temperature 200 ° C.), even if 10,000 sheets were passed continuously, the image and the roll were completely removed. No abnormalities were found.

[Comparative Example 1]
Primer No. for addition reaction type liquid silicone rubber on the surface of an aluminum shaft having a diameter of 20 mm and a length of 300 mm. 101 A / B (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied. After setting the shaft in the center of the mold and mounting the 50 μm fluorine PFA tube with the primer on the inner surface of the mold, the silicone rubber composition (1) was poured between the shaft and the tube at 140 ° C. for 20 The mixture was heat-cured for minutes and removed from the mold. This was further post-cured at 200 ° C. for 4 hours to prepare a PFA resin-coated silicone rubber roll having a rubber thickness of 2.0 mm and a length of 250 mm. When this roll was incorporated as a fixing roll of a laser printer and paper was passed (40 sheets / min, cored bar temperature 260 ° C., surface layer temperature 200 ° C.), toner fixing was insufficient from the first sheet. By fixing the sheet passing speed to 20 sheets / min, toner fixing becomes possible.

[Comparative Example 2]
Primer No. for addition reaction type liquid silicone rubber on the surface of an aluminum shaft having a diameter of 20 mm and a length of 300 mm. 101 A / B (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied. After setting the shaft in the center of the mold and mounting a 50 μm fluorine PFA tube with the primer on the inner surface, the silicone rubber composition (3) was poured between the shaft and the tube at The mixture was heat-cured for minutes and removed from the mold. This was further post-cured at 200 ° C. for 4 hours to prepare a PFA resin-coated silicone rubber roll having a rubber thickness of 2 mm and a length of 250 mm. When this roll was incorporated as a fixing roll of a laser printer and paper was passed (45 sheets / min, cored bar temperature 260 ° C., surface layer temperature 200 ° C.), the image started to be distorted after passing 2,000 sheets. When the sheet was stopped and the roll was taken out, the rubber near the roll axis was broken.

[Comparative Example 3]
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 shaft was set at the center of the mold, and the silicone rubber composition (4) was poured into the mold and heat-cured at 140 ° C. for 20 minutes. This was taken out of the mold to obtain a roll having a thickness of 0.6 mm and a silicone rubber layer formed on the roll axis. This roll is further set at the center of a mold in which a 50 μm fluorine PFA tube whose inner surface is primed is attached to the mold, and the silicone rubber composition (1) is injected between the roll and 120 ° C. for 30 minutes. Heat cured and removed from the mold. This was further post-cured at 200 ° C. for 4 hours to prepare a PFA resin-coated silicone rubber roll having a rubber thickness of 2.0 mm (inner layer 0.6 mm, outer layer 1.4 mm) and length of 250 mm. When this roll was incorporated as a fixing roll of a laser printer and paper was passed (45 sheets / min, cored bar temperature 260 ° C., surface layer temperature 200 ° C.), fixing was insufficient from the first sheet. By fixing the sheet passing speed to 29 sheets / min, toner fixing becomes possible.

[Example 2]
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 shaft was set in the center of the mold, and the silicone rubber composition (2) was poured into the mold, followed by heat curing at 140 ° C. for 20 minutes. This was taken out of the mold to obtain a roll having a thickness of 1.0 mm and a silicone rubber layer formed on the roll axis. A primer prepared by diluting KF99 (manufactured by Shin-Etsu Chemical Co., Ltd.) to 10% by mass with toluene was applied as a primer and dried at 95 ° C. for 30 minutes. This roll was further set at the center of the mold, and the silicone rubber composition (5) was injected, cured by heating at 120 ° C. for 30 minutes, and taken out from the mold. This was further post-cured at 200 ° C. for 2 hours to prepare a silicone rubber roll having a rubber thickness of 5 mm (inner layer: 1.0 mm, outer layer: 4.0 mm) and length of 250 mm. Dairy latex and silicone rubber primer GLP-103SR (manufactured by Daikin) are evenly applied to the surface of the cured product, heated at 80 ° C. for 10 minutes, and then further, Daiel latex GLS-213 is spray applied. And heated and fired at 300 ° C. for 1 hour to prepare a Daiel latex-coated silicone rubber roll.
When this roll was incorporated as a fixing roll for a color laser printer and paper was passed (30 sheets / minute, cored bar temperature 280 ° C., surface temperature 220 ° C.) No abnormalities were found.

[Comparative Example 4]
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 shaft was set at the center of the mold, and the silicone rubber composition (5) was poured into the mold, which was cured by heating at 140 ° C. for 20 minutes, and then removed from the mold. This was further post-cured at 200 ° C. for 2 hours to produce a silicone rubber roll having a rubber thickness of 5 mm and a length of 250 mm. Dairy latex and silicone rubber primer GLP-103SR (manufactured by Daikin) are evenly applied to the surface of the cured product, heated at 80 ° C. for 10 minutes, and then further, Daiel latex GLS-213 is spray applied. And heated and fired at 300 ° C. for 1 hour to prepare a Daiel latex-coated silicone rubber roll.
When this roll was incorporated as a fixing roll for a color laser printer and paper was passed (30 sheets / min, cored bar temperature 280 ° C., surface temperature 220 ° C.), the image started to be distorted after passing 8,000 sheets. After stopping at 100 sheets and taking out the roll, the rubber near the roll axis was broken.

[Comparative Example 5]
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 shaft was set at the center of the mold, and the silicone rubber composition (2) was poured into the mold, which was heated and cured at 140 ° C. for 20 minutes, and then removed from the mold. This was further post-cured at 200 ° C. for 2 hours to produce a silicone rubber roll having a rubber thickness of 5 mm and a length of 250 mm. Dairy latex and silicone rubber primer GLP-103SR (manufactured by Daikin) are evenly applied to the surface of the cured product, heated at 80 ° C. for 10 minutes, and then further, Daiel latex GLS-213 is spray applied. And heated and fired at 300 ° C. for 1 hour to prepare a Daiel latex-coated silicone rubber roll.
When this roll was incorporated as a fixing roll of a color laser printer and paper was passed (30 sheets / min, cored bar temperature 280 ° C., surface temperature 220 ° C.), toner fixing was insufficient from the first sheet. Sufficient toner fixing was obtained by reducing the sheet passing speed to 9 sheets / min.

Claims (7)

A first silicone rubber layer (inner layer) is provided on the outer periphery of the roll shaft, a second silicone rubber layer (outer layer) is provided on the outer side of the first silicone rubber layer, and a surface layer made of a fluororesin is further provided on the outer side. In the fixing roll having a silicone rubber inner layer and an outer layer,
(A) 100 parts by mass of an organopolysiloxane containing an alkenyl group bonded to at least two silicon atoms in one molecule ;
(B) 0.1 to 50 parts by mass of an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to at least a silicon atom in one molecule ;
(C) 0 to 1,000 parts by mass of an inorganic filler ,
(D) Amount of catalyst for addition reaction catalyst
And a molar ratio of the total amount of silicon-bonded hydrogen atoms of the component (B) to the alkenyl groups bonded to the silicon atoms of the component (A). A fixing roll having a silicone rubber inner layer of 0.5 to 2.0 and a silicone rubber outer layer of 0.3 to 1.5, wherein the silicone rubber inner layer is harder than the silicone rubber outer layer.   The hardness of the silicone rubber inner layer by durometer A is 2 or more and 30 or less, the hardness of the silicone rubber outer layer is 15 or less, and the rubber hardness of the silicone rubber outer layer is 2 points or more lower than the rubber hardness of the silicone rubber inner layer. The fixing roll described.   The thickness of the silicone rubber inner layer is 0.1 to 10 mm, the thickness of the silicone rubber outer layer is 0.3 to 30 mm, and the thickness of the silicone rubber inner layer is 2/3 or less of the thickness of the silicone rubber outer layer. The fixing roll according to claim 1 or 2, characterized in that The fixing roll according to any one of claims 1 to 3 , wherein the inner layer and the outer layer of the silicone rubber are each formed of dimethyl silicone rubber. The fixing roll is characterized in that the roll shaft (core metal) temperature during operation is 230 ° C. or higher, the temperature of the roll surface is 180 ° C. or higher, and the temperature difference between the core metal temperature and the roll surface is 30 ° C. or higher. The fixing roll according to any one of claims 1 to 4 . Fixing roll, fuser roll of any one of claims 1-5, characterized in that a roll having a heat source therein metal core. Fixing roll, the roll rotation speed during operation, A4 copies feeding speed for monochrome printing is 30 sheets / min or more, more of claims 1-6, characterized in that when it is 10 sheets / min or more color printing The fixing roll according to claim 1.