JP2000321912A - Fixing roller using composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To-provide a fixing roller excellent in toner release property, scratching resistance and wear resistance. SOLUTION: In this fixing and/or pressurizing roller, a composite material of a polyorganosiloxane and a fluoroelastomer containing no fluorocarbon resin or having dispersion of a fluorocarbon resin is used for at least the elastic material of the outermost layer. The composite material has a sea-island structure containing the polyorganosiloxane as the sea phase and the fluoroelastomer containing no fluorocarbon resin or having dispersion of a fluorocarbon resin as the island phase. The particle size of the island phase ranges 1 to 10 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a fixing unit of an electrophotographic image forming apparatus such as a copying machine and an LBP, and particularly, a fixing roller which is required to have both toner releasing property, scratch resistance and abrasion resistance. And a method for manufacturing the same, and a fixing device using the same.

[0002]

2. Description of the Related Art In an electrophotographic apparatus, as a pair of rollers for fixing toner by heat and pressure, that is, a fixing roller and a pressure roller, an elastic layer having a single layer or a multilayer structure is formed on a cylindrical cored bar. What was done is used.
Polyorganosiloxane (silicone rubber), fluoroelastomer, or the like, which is excellent in heat resistance, chemical resistance, weather resistance, and the like, is used as a material for forming these elastic layers.

[0003] Important characteristics required when these materials are used as an elastic body of the outermost layer in a fixing or pressure roller mainly include toner releasability, scratch resistance and abrasion resistance. The toner releasability refers to the difficulty in adhering toner to the roller surface, which occurs when fixing an electrostatically formed toner image between a fixing and pressing roller by heat and pressure. If the material used for the outermost layer of the roller has poor toner releasability, the toner adheres to the roller surface, causing a toner offset such that a copy image is missing. Further, even when a material having relatively excellent toner releasability that does not cause toner offset is used, by repeatedly fixing the toner image,
In some cases, toner releasability is deteriorated and toner offset occurs when the number of copies is several hundred or several thousand.
Therefore, it is important for the performance of the roller to use a material having an excellent toner releasing property for the outermost layer. The scratch resistance and abrasion resistance refer to the difficulty of scratching on the roller surface caused by repeatedly fixing a toner image. By repeatedly fixing the toner image, a member in contact with the fixing or pressure roller, for example, in the case of a fixing roller, a web for applying silicone oil and cleaning the offset toner to prevent toner offset. In some cases, offset toner, paper powder, and the like adhere to the contact portion, and a flaw may be generated on the roller surface due to such an adhered substance. Further, in the case of a pressure roller, for example, a blade for scraping off excess silicon oil may be in pressure contact, and offset toner or paper powder or the like adheres to the pressure contact portion, and such an adhered substance causes Scratches may occur on the roller surface. If a flaw is generated on the roller surface, in the case of a fixing roller, the flaw has an adverse effect on a copy image. In the case of a pressure roller, offset toner may accumulate in the flaws, and the toner may adhere to the back surface of a recording material such as paper, thereby causing contamination. If a material with poor scratch resistance and abrasion resistance is used for the outermost layer, the roller surface is likely to be scratched and the above-mentioned problems will occur, so a material with excellent scratch resistance and abrasion resistance will be used. It is also important to use it for the outermost layer.

[0004] The main material properties that determine the toner releasability, scratch resistance and abrasion resistance include surface energy and hardness, respectively. It is considered that the lower the surface energy of the material, the better the toner releasability. It is also considered that the higher the hardness of the material, the better the scratch resistance and wear resistance. A polyorganosiloxane having relatively low surface energy and hardness is excellent in toner releasability, but is considered to be inferior in scratch resistance and abrasion resistance. On the other hand, the fluoroelastomer has relatively high surface energy and hardness, and is excellent in scratch resistance and abrasion resistance, contrary to polyorganosiloxane, but is considered to be inferior in toner releasability.

Conventionally, a polyorganosiloxane containing spherical fused silica having an average particle size of 0.5 to 20 μm has been used for the purpose of improving the scratch resistance and abrasion resistance of the polyorganosiloxane (Japanese Patent Laid-Open No. 8-193166)
Also, there has been proposed a polyorganosiloxane containing a spherical tetrafluoroethylene resin (JP-A-9-12893). However, in each of these conventional examples, a resin is blended with polyorganosiloxane, and the properties of the polyorganosiloxane as an elastic body are impaired to some extent. Therefore, in order to obtain a composite material having good properties as an elastic body, it is considered effective to include not a resin but an elastic body excellent in scratch resistance and wear resistance in the polyorganosiloxane, One of them is a fluoroelastomer.

For this reason, in order to obtain materials having both excellent properties of polyorganosiloxane and fluoroelastomer, composite materials in which both are mixed have been studied. For example, an elastic layer is formed around an aluminum core using a composite material obtained by mixing a polyorganosiloxane and a fluoroelastomer mechanically or by dissolving and dispersing in an organic solvent (Japanese Unexamined Patent Application Publication No. 147126) or a composite material using a fluoroelastomer as a matrix component in which particles comprising at least one of a reactive silicone oil and a reactive fluorine oil are dispersed in the fluoroelastomer matrix (JP-A-9-96981).
Alternatively, an amine coupler having a silane side group and a hydrolyzable silane compound such as tetraethoxysilane are added, and a homogenous composite material in which a chemical bond between a fluoroelastomer and a polyorganosiloxane is generated through the addition to the fixing member. The used one (JP-A-308848) and the like have been proposed.

[0007] However, in the conventional example of JP-A-5-147126, a method of preparing a composite material by mechanical mixing has been proposed. Generally, the dispersion state of the composite material obtained by mechanical mixing is proposed. In general, the viscosity of polyorganosiloxane is low, and the Mooney viscosity of flutroelastomer is high, and the difference between the viscosities is too large to be easily dispersed. To several hundred μm. Considering that the particle diameter of the toner is several μm, it can be said that a satisfactory dispersion state has not been obtained. As another means for preparing a composite material in the conventional example of JP-A-5-147126, a method of dissolving and dispersing in an organic solvent has been proposed. In the composite material, the polarity of the polyorganosiloxane and the fluoroelastomer are significantly different, and the compatibility of the two is poor. Depending on the evaporation rate of the solvent, one of the composite materials becomes a large aggregate of about several tens to several hundreds μm, and the matrix becomes a large aggregate. May be present therein, and their dispersion may be coarse as well. In addition, in a full-color machine which requires a toner releasability more than a monochrome machine, there is a problem that the releasability is slightly insufficient because the surface energy of the fluorine rubber as the island phase is high.

In the conventional example of Japanese Patent Application Laid-Open No. 9-96981, in consideration of such a problem, particles composed of reactive silicone oil or reactive fluorine oil are partially fixed in a fluoroelastomer matrix by reaction. The dispersion state is maintained so that the particle diameter is 30 μm or less. However, in the composite material thus obtained, although the dispersion state is improved, the fluoroelastomer having the higher surface energy is the sea phase, so that the sea phase and the island phase are opposite to the conventional example. That is, the latter is considered to be more advantageous from the viewpoint of toner releasability than the composite material in which the polyorganosiloxane is in the sea phase.

Furthermore, Japanese Patent Application Laid-Open No. 6-308848 describes that a composite material composed of a homogeneous polyorganosiloxane and a fluoroelastomer integrated at the polymer molecular level can be obtained. It does not disclose a form of a composite material which is a dispersion having a sea-island structure in which a sea phase and a fluoroelastomer are an island phase.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner mold release using a composite material in which a fluoroelastomer is evenly dispersed at a level of several microns in a polyorganosiloxane (silicone rubber) as at least an outermost layer elastic body. An object of the present invention is to provide a fixing roller having excellent heat resistance, scratch resistance and abrasion resistance.

Another object of the present invention is to provide a toner mold release using a composite material in which a fluoroelastomer in which a fluororesin is previously dispersed in a polyorganosiloxane is evenly dispersed at a level of several microns as at least an outermost elastic body. An object of the present invention is to provide a fixing roller which is excellent in both heat resistance, scratch resistance and abrasion resistance and is suitable for a full-color machine.

Still another object of the present invention is to provide a method of manufacturing such a fixing roller and a fixing device using such a fixing roller.

[0013]

The above object of the present invention is achieved by the following inventions.

(1) A roller in which an elastic layer having a single-layer or multilayer structure is formed on the outer periphery of a cylindrical shaft, and at least the outermost layer of the elastic layer is made of a composite material of polyorganosiloxane and fluoroelastomer. In the fixing roller, according to the present invention, the composite material has a sea-island structure in which a polyorganosiloxane is a sea phase and a fluoroelastomer is an island phase, and the particle size of the island phase is 1 to 1;
It is characterized by being in the range of 0 μm. In the present invention, the fixing roller is a fixing roller and / or a pressure roller.

(2) The fixing roller according to the above (1), wherein a fluororesin is dispersed in the fluoroelastomer which is the island phase, and the fluororesin is present only in the fluoroelastomer which is the island phase.

(3) The mixing ratio of the fluoroelastomer (B) and the fluororesin (C) is from 100: 0 to 40:60 by weight (B) / (C), and the polyorganosiloxane (A) The fixing roller according to the above (1) or (2), wherein the compounding ratio of the fluoroelastomer and the fluoroelastomer (B) is set in a weight ratio (A) / (B) of 80:20 to 20:80.

(4) When preparing the composite material used for the fixing roller, the polyorganosiloxane and the fluoroelastomer, or the polyorganosiloxane and the fluoroelastomer in which the fluororesin is dispersed in advance are kneaded. A method for manufacturing a fixing roller according to the above (1) or (2).

(5) Viscosity 100 Pa · s to 1000 Pa
The fusing method according to (4), wherein the liquid polyorganosiloxane having a s (25 ° C.) and a fluoroelastomer having a Mooney viscosity of 70 ML (1 + 10) 100 ° C. or less are kneaded under heating conditions of 160 ° C. to 220 ° C. Roller manufacturing method.

(6) The method for producing a fixing roller according to the above (4) or (5), wherein both the polyorganosiloxane and the fluoroelastomer are made of a material which can be vulcanized with an organic peroxide.

(7) A polyorganosiloxane and a fluoroelastomer, or a polyorganosiloxane and a fluoroelastomer in which a fluororesin is previously dispersed are kneaded under heating conditions, and then at least a vulcanizing agent is blended at a temperature lower than the vulcanization temperature. Applying the obtained composition so as to form at least the outermost layer of the elastic layer formed on the outer periphery of the cylindrical shaft, and then heating and curing at a temperature not lower than the vulcanization temperature (1) or (1). The method for manufacturing the fixing roller according to 2).

(8) A fixing device used in an electrophotographic image forming apparatus, wherein the fixing device has the fixing and / or pressure roller described in any one of (1) to (3) above. apparatus.

In the invention (1), the roller has an island structure composed of a fluoroelastomer having a relatively high hardness and a sea phase composed of a polyorganosiloxane having a relatively low hardness. The stress on the outermost layer of the roller due to the attachment to the members that are present can be reduced by being dispersed in the sea phase, and the elasticity against the stress is obtained in the island phase, so that it is difficult to deform, It is considered that scratch resistance and abrasion resistance can be exhibited. Further, it is considered that good toner releasability can be obtained because the polyorganosiloxane is in the sea phase and the particle size of the island phase made of the fluoroelastomer is kept in the range of 1 to 10 μm. Can be

In the invention of (2), the polyorganosiloxane has a sea-island structure in which the sea phase and the fluoroelastomer are the island phase.
Fluororesins having lower surface energy than polyorganosiloxane are present only in the fluoroelastomer which is the island phase. As a result, the relatively high surface energy of the fluoroelastomer that is the island phase can be efficiently improved, and even if the blending ratio of the fluororesin is smaller than the case where these three materials are simply dispersed, it is sufficient. In addition, it can function as a soft material having the flexibility required for obtaining high image quality. Therefore, it is possible to provide a fixing roller suitable for a full-color machine.

In the invention of (3), by blending at least 20% of the polyorganosiloxane and at least 20% of the fluoroelastomer, the polyorganosiloxane having a lower surface energy than that of the fluoroelastomer is added to the sea phase. This makes it easier to make the fluoroelastomer into an island phase. Further, by setting the upper limit of the blending amount of the fluororesin to 60 with respect to the fluoroelastomer 40, it becomes possible to obtain the flexibility required for toner releasability and high image quality.

In the invention of (4), when preparing the reconstituted material, by heating both the polyorganosiloxane and the fluoroelastomer which may contain a fluororesin, the respective viscosities are made lower than at room temperature, In addition, the difference in viscosity between the two can be reduced. Thereby, the dispersibility of each material at the time of kneading is improved, the polyorganosiloxane having a lower viscosity becomes a sea phase, the fluoroelastomer having a higher viscosity becomes an island phase, and the particle diameter of the island phase is 1 to 1. It is possible to prepare a composite material having a sea-island structure in the range of 10 μm.

In the invention of (5), the heating condition is set to 160
° to 220 ° C, even when using a liquid polyorganosiloxane, at a level of several microns,
It is possible to obtain a composite material in which a fluoroelastomer which may contain a fluororesin is evenly dispersed in a liquid polyorganosiloxane.

In the invention of (6), by selecting a peroxide reaction system as a vulcanization system for the polyorganosiloxane and a peroxide vulcanization system as a vulcanization system for the fluoroelastomer, the crosslinking between the polyorganosiloxane and the fluoroelastomer can be achieved. The reaction can be unified into a radical reaction system.

According to the invention (7), the fixing roller according to the above (1) or (2), which has good scratch resistance and abrasion resistance and excellent toner releasing property, can be easily produced.

In the invention (8), the above (1) to (1)
By using the fixing roller described in any of (3), the toner has releasability and scratch resistance of the roller.
It is possible to provide a fixing device used in an electrophotographic image forming apparatus which has excellent wear resistance and can obtain a high quality toner image.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the "particle size" of the island phase means that the maximum diameter portion of the particle is fixed as the long axis direction, and the short axis is newly set so that the area of the particles becomes equal. It means the average value of the diameter of the major axis and the diameter of the minor axis when the ellipse is set.

Examples of the polymer species of the polyorganosiloxane (silicone rubber) used in the present invention include dimethylsiloxane, methylvinylsiloxane, methylphenylsiloxane, methylfluoroalkylsiloxane and the like. However, a part thereof may be branched or form a three-dimensional structure, or a homopolymer, a copolymer or a mixture thereof may be used.

Further, the terminal of the molecular chain of the polyorganosiloxane may be substituted with, for example, an alkoxy group, a trimethylsilyl group, a dimethylvinylsilyl group, a methylphenylvinylsilyl group, a methyldiphenylsilyl group or the like. Among them, a dimethylvinylsilyl group is preferred.

The degree of polymerization of this polyorganosiloxane is
400 to 10,000, preferably 1,000 to 9.0
If it is less than 400, the mechanical strength and the like are not excellent, while if it exceeds 10,000, it is difficult to obtain. In addition, as a material form of these polyorganosiloxanes, a millable type or a liquid type can be mentioned, and either polyorganosiloxane can be used.

As the liquid polyorganosiloxane, those having a viscosity of 100 Pa · s to 1000 Pa · s (25 ° C.) are preferably used. If the viscosity of the liquid polyorganosiloxane is less than 100 Pa · s, the viscosity may be too low to obtain an evenly dispersed state during kneading with the fluoroelastomer by heating.

Next, as the polymer species of the fluoroelastomer used in the present invention, for example, vinylidene fluoride-based fluoroelastomer, vinylidene fluoride-hexafluoropropylene binary copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoropolymer Ethylene terpolymer, tetrafluoroethylene-
Propylene-based fluoroelastomer, fluorine-containing vinyl ether-based fluoroelastomer, tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer, fluorine-containing phosphazene rubber, and the like;
Vinylidene fluoride-hexafluoropropylene-
Tetrafluoroethylene terpolymer and vinylidene fluoride-hexafluoropropylene binary copolymer are preferably used. The peroxide vulcanized fluoroelastomer used in the present invention is of a type in which a halogen, particularly iodine and / or bromine is introduced into the terminal and / or the side chain of the molecular chain. It is performed by

The fluoroelastomer used in the present invention preferably has a Mooney viscosity of 70 ML (1 + 10) 100 ° C. or less. That is, when the Mooney viscosity is higher than that, a uniform dispersion state may not be obtained during the heating and kneading with the polyorganosiloxane.

The mixing ratio of the above-mentioned polyorganosiloxane (A) and fluoroelastomer (B) is expressed in terms of weight ratio.
(A): (B) = It is desirable to set in the range of 80:20 to 20:80. That is, by blending at least 20% of the polyorganosiloxane and at least 20% of the fluoroelastomer, the polyorganosiloxane having a lower surface energy than the fluoroelastomer can be used as the sea phase and the fluoroelastomer can be used as the island phase. It will be easier. Further, when the fluororesin (C) is contained in the fluoroelastomer (B), the mixing ratio is the weight ratio (B).
/ (C) is preferably in the range of 99: 1 to 40:60. In order to obtain the flexibility required for high image quality, it is preferable that the blending amount of the fluororesin is as small as possible.
It is particularly preferable that the weight ratio of (C) is 70:30 or less. Further, in order to make a polyorganosiloxane having a lower surface energy than a fluoroelastomer into a sea phase, a minimum of 20% of the polyorganosiloxane is required, and a minimum of 20% is required for the fluoroelastomer to improve durability and abrasion resistance. %is necessary. That is, it is preferable that the mixing ratio is such that the properties of the three materials described above are utilized.

As a method for preparing the composite material, a method in which a polyorganosiloxane and a fluoroelastomer or a fluoroelastomer in which a fluororesin is dispersed in advance is kneaded under heating conditions can be adopted. At this time, the heating temperature is preferably from 100 ° to 250 ° C., and the kneading time is preferably from 2 minutes to 1 hour. As the kneader, various extruders, mixers, Banbury mixers, kneaders, rolls, and the like are used, but are not limited thereto.

At this time, if the kneading temperature exceeds 250 ° C., the polyorganosiloxane and the fluoroelastomer may be thermally degraded. On the other hand, if the kneading time is shorter than 2 minutes, it is difficult to obtain a composite material having a uniform dispersion state. On the other hand, if the kneading time exceeds 1 hour, the kneading cost increases, which is not preferable.

Particularly, the viscosity is 100 Pa · s to 1000 Pa
When kneading a liquid polyorganosiloxane having a range of s (25 ° C.) and a fluoroelastomer having a Mooney viscosity of 70 ML (1 + 10) 100 ° C. or less, the heating conditions must be in the range of 160 ° C. to 220 ° C. From the viewpoint of workability, it is preferable to use an internal mixer such as a mixer, a Banbury mixer, or a kneader as a kneading method.

The composite material contains a vulcanizing agent and a vulcanizing aid in addition to the polyorganosiloxane and the fluoroelastomer, and may contain a reinforcing compound such as carbon black or silica.

As a method for preparing a composite material, besides the above-mentioned method, a pre-vulcanized fluoroelastomer may be shredded or finely divided, and the resulting particles and an unvulcanized polyorganosiloxane may be kneaded. May be.

The polyorganosiloxane vulcanization system used in the present invention includes a condensation reaction system, an addition reaction system, and a peroxide reaction system. In addition, the vulcanization system of fluoroelastomer includes
There are polyol vulcanization systems, polyamine vulcanization systems, and peroxide vulcanization systems.

When a peroxide reaction system is selected as the vulcanization system of the polyorganosiloxane and a peroxide vulcanization system is selected as the vulcanization system of the fluoroelastomer, both the crosslinking reaction between the polyorganosiloxane and the fluoroelastomer is a radical reaction. There is an advantage that the reaction system and the vulcanizing agent can be unified.

The vulcanizing agent used in this case is an organic peroxide such as diacyl peroxide, peroxyester,
It is roughly divided into four types: peroxyketals and dialkyl peroxides.

Examples of the diacyl peroxide include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, bis (p-chlorobenzoyl) peroxide, bis (o-methylbenzoyl) peroxide and the like. As peroxyester,
t-butyl peroxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-
Butyl peroxyisopropyl carbonate and the like can be mentioned.

The peroxyketal includes 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy)
Examples thereof include cyclohexane, 2,2-bios (t-butylperoxy) octane, and n-butyl4,4-bis (t-butylperoxy) valerate.

As the dialkyl peroxide,
Di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, α, α-bis (t
-Butyolperoxy-m-isopropyl) benzene,
2,5-dimethyl 2,5-di (t-butylperoxy)
Hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 and the like can be mentioned.

These organic peroxides are used in the form of industrial pure products, pastes using silicone gum or silicone oil as a binder, or powders obtained by dusting powder such as calcium carbonate.

The organic peroxide used for vulcanizing the composite material of the polyorganosiloxane and the fluoroelastomer is not particularly limited, but may be dicumyl peroxide or 2,5-dialkyl peroxide belonging to the above-mentioned dialkyl peroxides. Preferably, dimethyl-2,5-di (t-butylperoxy) hexane is used.

The compounding amounts of the organic peroxides are (A) and (B)
The amount is 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the mixed elastomer component composed of the components. If the amount is too small, crosslinking of the elastomer component becomes insufficient and sufficient mechanical If the strength is not obtained, on the other hand, if it is too large, the crosslink density of the elastomer component increases, and the elongation of the obtained composition decreases.

As the vulcanization aid, ethylene dimethacrylate, 1,3-butylene dimethacrylate, 1,4-butylene dimethacrylate, 1,6-
Hexanediol dimethacrylate, polyethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 2,2'-bis (4-methacryloyldiethoxyphenyl) propane, trimethylolpropane Trimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, divinylbenzene, N, N'-methylenebisacrylamide,
Polyfunctional vinyl monomers such as p-quinone dioxime, p, p'-dibenzoylquinone dioxime, triazinedithiol, triallyl cyanurate, triallyl isocyanurate, bismaleimide, and silicone oil having a high vinyl group content are used. In particular, triallyl isocyanurate is preferably used.

The amount of the vulcanization aid is 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the dispersion composite of the polyorganosiloxane and the fluoroelastomer.
Parts by weight.

The kneading temperature at the time of adding the vulcanization aid and the organic peroxide as the vulcanizing agent must be a temperature at which the vulcanization reaction does not take place, and is preferably 10 ° C. 8
0 ° C, more preferably 20 ° to 60 ° C.

When a polyol vulcanization system is used for the fluoroelastomer (B), the above-mentioned vulcanizing agent, vulcanization aid and the like cannot be used for the component (B). Therefore, a vulcanizing agent for the polyorganosiloxane (A) and a vulcanizing agent and a vulcanizing aid for (B) must be added.

Here, as the polyol vulcanizing agent, polyhydroxy aromatic compounds such as hydroquinone, bisphenol A, bisphenol AF and salts thereof, and fluorinated aliphatic diols are used.

The amount of these polyol crosslinking agents added is
(B) 0.1 to 20 parts by weight with respect to 100 parts by weight of the component,
It is preferably about 1 to 10 parts by weight.

Examples of polyol vulcanization accelerators include quaternary ammonium compounds such as benzyltriethylammonium chloride, methyltrioctylammonium chloride and tetrahexylammonium tetrafluoroborate; benzyltrioctylphosphonium bromide;
Examples thereof include quaternary phosphonium compounds such as benzyltriphenylphosphonium chloride and m-trifluoromethylbenzyltrioctylphosphonium chloride.

The amount of such a vulcanization accelerator added is (B)
It is usually about 0.2 to 10 parts by weight based on 100 parts by weight of the component.

The composite material used for the outermost layer of the elastic body of the fixing and / or pressure roller of the present invention is composed of a polyorganosiloxane (A) as a main component and a fluoroelastomer (B) component which may contain a fluororesin. In addition, various compounding agents can be contained.

These compounding agents may be added as needed at any stage before vulcanization of the dispersed composite, but preferably after heating and kneading (A) and (B). Stage is good.

Examples of the reinforcing filler include silica, carbon black, quartz powder and the like.

Examples of the anti-aging agent include quinolines, phosphates, phenylenediamines, cresols, phenols and metal salts of dithiocarbamates. Examples of the heat-resistant agent include cerium oxide, iron oxide and iron naphthenate. , Potassium hydroxide and potassium naphthenate may be blended. In addition, a coloring agent, an ultraviolet absorber, a foaming agent, and the like can be optionally added as needed.

The fixing and / or pressure roller of the present invention can be manufactured, for example, as follows. That is, the polyorganosiloxane and the fluoroelastomer, in which the fluororesin may be dispersed in advance, are kneaded under heating conditions as described above to make the fluoroelastomer 1 to 10
μm particles are uniformly dispersed, and then a vulcanizing agent, a vulcanization aid and the like are added and mixed at a temperature not higher than the vulcanization temperature as described above, and the resulting mixture is preliminarily coated with a primer. Press-molding by transfer using a mold is performed so as to be at least the outermost layer of the elastic layer formed on the outer periphery of the uniformly coated and dried cylindrical shaft (core bar), and vulcanization and demolding are performed. It is manufactured through a mold, secondary vulcanization and polishing processes. When a liquid polyorganosiloxane is used, the viscosity is 100 Pa as described above.
Liquid polyorganosiloxane having a Mooney viscosity of 70 ML (1+
10) Fluoroelastomer having a temperature of 100 ° C. or less
Kneading is performed under heating conditions of 0 ° C. to 220 ° C., and then a vulcanization aid and a vulcanizing agent are blended in a temperature range in which a vulcanization reaction does not occur. Prepare. Next, a cylindrical shaft body (roller core metal or a roller on which a heat-resistant elastic layer is formed) on which a primer has been uniformly applied and dried in advance is prepared, press-molded by transfer using a mold, and removed. A roller can be manufactured through a mold, a secondary vulcanization, and a polishing process.

FIGS. 1 and 2 show a roller having a single-layer structure thus obtained. 1 and 2, reference numeral 1 denotes a roller core, and reference numeral 2 denotes an elastic layer (outermost layer) made of a composite material of a fluoroelastomer which may contain a polyorganosiloxane and a fluororesin. Next, FIG. 3 shows a roller having a two-layer structure. In the roller having the two-layer structure, first, a heat-resistant elastic layer 3 made of a conventional silicone rubber or the like is formed on the outer periphery of the roller core 1, and an elastic material made of the composite material of the present invention is formed on the outer periphery of the elastic layer 3. The body layer 2 is formed. The roller of the present invention is not limited to the above-described roller having a single-layer or two-layer structure, and may have a multilayer structure having three or more layers.

The roller of the present invention can be used not only as a fixing and pressing roller as a fixing member of an electrophotographic image forming apparatus, but also as a fixing member.
The present invention can be applied to other uses such as an oil supply roller and an oil regulating blade as fixing members.

[0067]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Linear dimethylpolysiloxane 4 having a viscosity of 10,000 Pa · s at 25 ° C. and having a dimethylvinylsiloxy group at both ends blocked
0 parts by weight, a linear polysiloxane segment having a viscosity of 30 Pa · s at 25 ° C. and having about 300 continuous bifunctional dimethylsiloxane units, and one vinyl bonded to both ends thereof A liquid polyorganosiloxane having a viscosity of 700 Pa · s at 25 ° C. as a whole, comprising 60 parts by weight of a block polymer comprising a branched polymethylsiloxane segment having a group, and iodine as a reactive group, and having a Mooney viscosity of 60
Equal amounts (150 g) of a fluoroelastomer (trade name: G902, manufactured by Daikin Industries, Ltd.) having an ML (1 + 10) of 100 ° C. are mixed (universal mixing stirrer model 5D)
MV-01-r manufactured by Dalton Co., Ltd.)
After kneading with heating to about 50 ° C., at about 50 ° C., 6 g of triallyl isocyanurate as a vulcanizing aid and 2,2 as a vulcanizing agent
4.5 g of 5-dimethyl-2,5-di (t-butylperoxy) hexane was added and kneaded again. The composite material thus prepared was press-molded at 170 ° C. for 15 minutes to produce a 1 mm-thick rubber sheet, and then subjected to secondary vulcanization (180 ° C., 24 hours) in a heating oven. The dispersion state on the surface of the obtained sheet was examined by performing element mapping with an electron beam probe microanalyzer (EPMA) using a low vacuum scanning electron microscope (LV-SEM) (SEM: JEOL Ltd.). JSM-5800LV type, EPMA: DX-Prime type, manufactured by Philips Japan, acceleration voltage: 10 kV, measurement mode: low vacuum mode (about 40 Pa), measurement magnification: 1
000 times, detector: energy dispersive (EDS), mapping element: C, F, Si).

As a result, as shown in the dispersed state in FIG. 4, the sea phase is polyorganosiloxane, the island phase is fluoroelastomer, and the particle size of the island phase is 1 to 10 μm.
Was found to be in the range. The same dispersibility was obtained by using other kneading methods other than the mixer.

Comparative Example 1 A vinyl group was contained as a reactive group and the viscosity was 700 Pa · s.
Containing iodine as a reactive group with a polyorganosiloxane having a Mooney viscosity of 60 ML (1 + 10) at 100 ° C.
Of the fluoroelastomer is kneaded at room temperature using an open roll (manufactured by Kansai Roll Co., Ltd.) having a shearing force greater than that of a mixer, and then triallylisocyanurate as a vulcanization aid is used. 6g
And 4.5 g of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane as a vulcanizing agent, and kneaded again at room temperature using an open roll. The composite material thus prepared was press-molded at 170 ° C. for 15 minutes to produce a 1 mm-thick rubber sheet, and then subjected to secondary vulcanization (180 ° C., 24 hours) in a heating oven. The state of dispersion on the surface of this sheet was examined using the same method as in Example 1.

As a result, it was found that the sea phase was a polyorganosiloxane and the island phase was a fluoroelastomer, and the size of particles in the island phase was about 50 to 200 μm.

Example 2 A roller core (outer diameter φ) coated with a primer (Monicas V-16A / B manufactured by Yokohama Polymer Research Institute) uniformly and dried in advance.
Using a composite material prepared in the same manner as in Example 1 and press molding by transfer using a mold, demolding, and secondary vulcanizing in a heating oven, The roller (outside diameter φ59.
4, rubber thickness 250 μm). This roller was incorporated in a monochrome electrophotographic copying machine as a fixing roller, and a copy durability test was performed.

<Structure of Fixing Apparatus> FIG. 5 shows the structure of a fixing apparatus used for verifying the effect of the present invention. The fixing device includes a fixing roller 5 as an upper roller of the fixing device and a pressure roller 4 as a lower roller. At the center of the fixing roller 4, two heaters 6 composed of halogen lamps are incorporated. The fixing temperature is maintained at a set temperature by controlling the output of the heater 6 based on the surface temperature of the fixing roller 5 measured by the thermistor 7. The web 8 impregnated with silicone oil is brought into two-point contact with the fixing roller 4 in order to prevent toner offset, and while the contact surface of the web 8 is gradually moved by the winding mechanism, the silicone oil is applied to the fixing roller 4. And cleaning the offset toner. The roller manufactured by the above method was incorporated as a fixing roller 4 and a copy durability test was performed.

Comparative Example 2 A roller was finished in the same manner as in Example 2 except that a composite material was prepared in the same manner as in Comparative Example 1, and a copy durability test was performed.

Comparative Example 3 To 300 g of the polyorganosiloxane used in Example 1, 6 g of triallyl isocyanurate as a vulcanization aid and 2,5-dimethyl-2,5-di (t-butylper) as a vulcanizing agent were added. Using a material containing 4.5 g of oxy) hexane, a roller was manufactured in the same manner as in Example 2, and a copy durability test was performed.

Comparative Example 4 To 300 g of the fluoroelastomer used in Example 1, 6 g of triallyl isocyanurate as a vulcanizing aid and 2,5-dimethyl-2,5-di (t-butylperoxy) as a vulcanizing agent were added. A roller was manufactured in the same manner as in Example 2 using a material containing 4.5 g of hexane, and a copy durability test was performed.

From the results of Example 1 and Comparative Example 1, the viscosity was 1
A liquid polyorganosiloxane in the range of 00 Pa · s to 1000 Pa · s (25 ° C.);
When kneading a fluoroelastomer having ML (1 + 10) of 100 ° C. or less, by performing the heating under a heating condition of 160 ° C. to 220 ° C., the dispersion state can be reduced from one order as compared with the case of simply mechanically kneading without heating. Improved by two orders,
It can be seen that a composite material having a uniform dispersion state at a micron level can be obtained.

Next, the results of the copy durability test of Example 2 and Comparative Examples 2 to 4 are shown in Table 1.

[0079]

[Table 1] Table 1 is described below. First, in the case of Example 2, when 100,000 sheets were passed, no image omission or image unevenness due to toner offset was found in the copy image, and a good copy image was obtained. In addition, no scratches due to deposits on the web that would affect the copy image were observed on the roller surface after the durability. On the other hand, in the case of Comparative Example 2, an image omission occurred due to toner offset in the copied image when 50,000 sheets were passed. In the case of Comparative Example 3, 2
During the passing of many sheets, a large number of scratches were visually observed on the roller surface, and the scratches appeared as missing streaks on the copy image. In the case of Comparative Example 4, toner offset occurred when 20,000 sheets were passed.

Examples 3 and 4 The fluoroelastomer (B) and the fluororesin (C) were previously mixed at a weight ratio shown in Table 2 using an open roll.
Next, the mixture of (B) and (C) and the polyorganosiloxane (A) are mixed while being heated (about 200 ° C.) in an internal mixer, and then vulcanized at a vulcanization temperature or lower (about 50 ° C.). An auxiliary agent and a vulcanizing agent were added at the ratios shown in the same table and mixed again to prepare a rubber composition. Next, the rubber composition was vulcanized and polished together with an aluminum mandrel having an outer peripheral surface coated with an adhesive to form an elastic layer having a thickness of 250 μm. Then, by subjecting this to secondary vulcanization, the desired roller having a single-layer structure shown in FIGS. 1 and 2 was formed.

[0081]

[Table 2] * 1: G902 (peroxide vulcanized) manufactured by Daikin Industries, Ltd. * 2: Lubron L5F (PTF manufactured by Daikin Industries, Ltd.)
E) * 3: The total of (A) and (B) was taken as 100 parts by weight, and the compounding amount based on the total amount * 4: "TAIC" (triallyl isocyanurate) manufactured by Nippon Kasei Co., Ltd. * 5: Nippon Yushi Co., Ltd. ) Made “Perhexa 25B”
(2,5-dimethyl-2,5-di (t-butylperoxy) hexane)

The obtained roller was incorporated into an electrophotographic copying machine as a fixing roller, and a paper passing durability test was performed. As a result, each of the rollers of Examples 1 and 2 has a
There were no abnormalities in the rollers even at 00000 or more.

[0083]

The fixing and / or pressure roller of the present invention has a sea-island structure in which the polyorganosiloxane is in the sea phase and the fluoroelastomer which may contain a fluororesin is in the island phase, and the particles of the island phase A composite material of a polyorganosiloxane and a fluoroelastomer which may contain a fluororesin, which is evenly dispersed at a micron level in which the size of the particles is in the range of 1 to 10 μm, is used as at least the outermost layer elastic body. As is clear from the results of the copy durability test of the examples, toner release properties, scratch resistance, and abrasion resistance are both excellent. Further, in preparing the composite material, the kneading of a polyorganosiloxane and a fluoroelastomer which may contain a fluororesin under heating conditions improves the dispersibility of each material, thereby improving the dispersibility of each material. The material can be prepared. Further, the fixing device of the present invention is excellent in the toner releasability, scratch resistance, and abrasion resistance of the roller, and can obtain a high-quality image.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fixing roller having a single-layer structure according to the present invention.

FIG. 2 is a perspective view of a fixing roller having a single-layer structure according to the present invention, and an enlarged cross-sectional view of a part thereof.

FIG. 3 is a sectional view of a fixing roller having a two-layer structure according to the present invention.

FIG. 4 is a schematic plan view showing a dispersion state of a composite material used for a fixing roller according to the present invention.

FIG. 5 is a configuration diagram of a fixing device in a monochrome copying machine used to verify the effect of the present invention.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 83/04 C08L 83/04 F16C 13/00 F16C 13/00 AB E (72) Inventor Osamu May Ota-ku, Tokyo 3-30-2 Shimomaruko Canon Inc. (72) Inventor Masaaki Takahashi 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo (72) Inventor Kazuo Kishino 3-30 Shimomaruko, Ota-ku, Tokyo No. 2 Canon Inc.

Claims (8)

[Claims] 1. A roller in which an elastic layer having a single layer or a multilayer structure is formed on the outer periphery of a cylindrical shaft, and at least the outermost layer of the elastic layer is a fixing member made of a composite material of polyorganosiloxane and fluoroelastomer. And / or a pressure roller, wherein the composite material has a sea-island structure in which the polyorganosiloxane is a sea phase and the fluoroelastomer is an island phase, and the particle size of the island phase is 1 to 1.
A fixing roller having a range of 10 μm. 2. The fixing roller according to claim 1, wherein a fluororesin is dispersed in the fluoroelastomer which is the island phase, and the fluororesin is present only in the fluoroelastomer which is the island phase. 3. The mixing ratio of the fluoroelastomer (B) and the fluororesin (C) is 10 by weight (B) / (C).
0: 0 to 40:60, and the mixing ratio of the polyorganosiloxane (A) and the fluoroelastomer (B) is set to 80:20 to 20:80 by weight ratio (A) / (B). The fixing roller according to claim 1. 4. When preparing a composite material to be used for the fixing and / or pressure roller, a polyorganosiloxane and a fluoroelastomer, or a polyorganosiloxane and a fluoroelastomer in which a fluororesin is dispersed in advance, are heated under heating conditions. 2. The kneading method according to claim 1, wherein
3. The method for manufacturing a fixing roller according to item 2. 5. A viscosity of 100 Pa · s to 1000 Pa · s.
5. The production of the fixing roller according to claim 4, wherein the liquid polyorganosiloxane (25 ° C.) and the fluoroelastomer having a Mooney viscosity of 70 ML (1 + 10) 100 ° C. or less are kneaded under heating conditions of 160 ° C. to 220 ° C. 5. Method. 6. The method for producing a fixing roller according to claim 4, wherein both the polyorganosiloxane and the fluoroelastomer are made of a material that can be vulcanized with an organic peroxide. 7. Kneading a polyorganosiloxane and a fluoroelastomer, or a polyorganosiloxane and a fluoroelastomer in which a fluororesin is previously dispersed, under heating conditions, and then blending at least a vulcanizing agent at a temperature not higher than the vulcanization temperature, The obtained compound is applied so as to form at least the outermost layer of an elastic layer formed on the outer periphery of the cylindrical shaft, and then cured by heating at a temperature not lower than the vulcanization temperature. Manufacturing method of a fixed fixing roller. 8. A fixing device for use in an electrophotographic image forming apparatus, comprising a fixing roller according to claim 1. Description: