JP2013015683A - Fixing member and method for manufacturing the same, and fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing member having a release layer comprising a rubber that is excellent in toner releasability without inducing toner offset, since the rubber has high affinity with wax as a release agent component of a toner and has low affinity with a binder resin as a main component of a toner, and to provide a method for manufacturing a fixing member having a release layer comprising the rubber.SOLUTION: The fixing member has a toner release layer comprising a crosslinked rubber of a mixture of a least three components, which are: a fluorine rubber comprising a ternary copolymer of vinylidene fluoride, tetrafluoroethylene and perfluoroalkyl vinylether and having a fluorine concentration of 65 mass% or more; a silicone-based surfactant; and a fluorine-based surfactant having a hydrophilic group and an oleophilic group and having 4 to 6 carbon atoms in a perfluoroalkyl group.

Description

  The present invention relates to a fixing member used for fixing toner in an electrophotographic image forming apparatus, a manufacturing method thereof, and a fixing device.

  High toner releasability is required on the surface of the fixing member. That is, when a toner image electrostatically formed on a recording material such as paper is fixed by applying heat, pressure or the like, it is required to suppress toner adhesion to the surface of the fixing member. When the toner adheres to the surface of the fixing member, the toner image formed on the recording material is partially chipped. Further, the toner adhering to the surface of the fixing member is fixed to the recording material conveyed next, and the quality of the electrophotographic image of the recording material is lowered. Therefore, it can be said that how to improve the toner release property of the toner release layer constituting the surface of the fixing member is important in terms of the performance of the fixing member.

On the other hand, flexibility is required for the surface layer of the fixing member. That is, since the flexible surface layer has high followability to the unevenness of the paper fiber, it can transfer heat well to the toner that has entered the concave portion of the paper fiber. Therefore, some surface layers of the fixing member contain rubber.
However, since rubber generally has a higher surface energy than fluororesin, it is inferior in toner releasability. For this reason, in color oilless fixing, only a fluororesin is put into practical use as a material for the release layer, and a fixing member having a release layer containing rubber has not been put into practical use at present. Under such circumstances, proposals have been made for obtaining a fixing member having a surface layer having both excellent toner releasability and flexibility.

  In Patent Document 1, for the purpose of making the surface layer flexibility and toner releasability compatible at a high level, a polyrubber having excellent affinity for fluoro rubber having an ether bond in the molecule and wax of a color toner is disclosed. A fixing member having a release layer containing a silicone-based surfactant having an ether structure has been proposed. Patent Document 2 discloses a fixing layer having a surface layer that is flexible and has excellent toner releasability by containing a fluororubber and a nonionic fluorosurfactant in the surface layer. A member is disclosed.

JP 2007-058197 A JP 2005-215153 A

  However, the present inventors have recognized that further improvement in toner releasability of a flexible surface layer containing fluororubber is necessary in view of the recent trend of lowering the melting point of toner.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fixing member having a toner release layer containing fluororubber and a method for producing the same for which toner release properties are further improved. Another object of the present invention is to provide a fixing device that contributes to the formation of high-quality electrophotographic images.

  According to the present invention, there is provided a fixing member having a base material and a toner release layer, wherein the toner release layer is formed by crosslinking a mixture of fluororubber, silicone surfactant, and fluorosurfactant. The fluororubber comprises a terpolymer of vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl vinyl ether, and has a fluorine concentration of 65% by mass or more, and the fluorosurfactant is A fixing member having a hydrophilic group and a lipophilic group and having a perfluoroalkyl group having 4 to 6 carbon atoms is provided.

Further, according to the present invention, there is provided a method for producing the fixing member, comprising a terpolymer of vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl vinyl ether, and having a fluorine concentration of 65% by mass or more. A toner release layer comprising: a fluororubber, a silicone surfactant, and a fluorosurfactant having a hydrophilic group and a lipophilic group and having a perfluoroalkyl group having 4 to 6 carbon atoms There is provided a method for producing a fixing member having a step of forming a toner release layer by curing a coating film of a forming coating solution.
Furthermore, according to the present invention, there is provided a fixing device for use in an electrophotographic image forming apparatus, the fixing device having the fixing member described above.

  According to the present invention, it is possible to obtain a fixing member having a toner release layer that is flexible and has high toner release properties. Further, according to the present invention, it is possible to obtain a fixing device capable of forming a high-quality electrophotographic image.

It is a schematic diagram which shows an example of the cross-sectional layer structure of the fixing member which concerns on this invention. 1 is a schematic cross-sectional view showing an example of a low pressure type fixing device according to the present invention.

An example of a cross-sectional layer structure of the fixing member according to the present invention is shown in FIG. In FIG. 1, 1 is a toner release layer, 2 is a flexible heat conductive layer containing silicone rubber or the like, and 3 is a substrate.
The toner release layer according to the present invention includes a cross-linked product of a mixture of fluororubber, silicone surfactant, and fluorosurfactant.

<Fluorosurfactant>
In the present invention, the fluorosurfactant has a hydrophilic group and a lipophilic group, and the perfluoroalkyl group has 4 to 6 carbon atoms. The hydrophilic group is an ether group. Examples of the hydrocarbon having an ether group include alkylene oxides such as ethylene oxide and propylene oxide. In the present invention, the lipophilic group has an effect of supplementarily increasing the affinity with the wax, and specifically includes a hydrocarbon group. The carbon number of the perfluoroalkyl group greatly affects the exposure of the perfluoroalkyl group to the member surface. When the carbon number is 8 or more, the perfluoroalkyl group is easily exposed to the member surface. As a result, the perfluoroalkyl group is undesirably exposed on the rubber surface which is the release layer of the present invention, and the effect of improving the affinity of the silicone surfactant with the wax is hindered. Moreover, when the carbon number of the perfluoroalkyl group is less than 4, even if a fluorosurfactant is added to the fluororubber, it may be aggregated without being dispersed. Therefore, in the present invention, the carbon number of the perfluoroalkyl group is 4 or more and less than 8, particularly 6 or less because it is easily available.

  Further, the blending amount of the fluorosurfactant is more preferably 10 parts by mass or less with respect to a total of 100 parts by mass of the fluororubber and the silicone surfactant described later. By setting the blending amount to 10 parts by mass or less, the effect of repelling the binder resin of the toner main component by the fluororubber having a high fluorine concentration is surely expressed.

<Fluorine rubber>
The fluororubber according to the present invention is a cross-linked product of fluororubber composed of a terpolymer of vinylidene fluoride, tetrafluoroethylene and perfluoroalkyl vinyl ether, and having a fluorine concentration of 65% by mass or more.

  Specifically, the fluororubber comprises a terpolymer of vinylidene fluoride, tetrafluoroethylene, and perfluoromethyl vinyl ether, and a radical reaction point in which molecular chain terminal or side chain is substituted with iodine or bromine. Have This fluororubber is a radical reaction initiator such as an organic peroxide, or a reaction for extracting an iodine or bromine atom by irradiation with an electron beam, and a crosslinking aid such as triallyl isocyanurate. Crosslinking proceeds by a radical reaction to an allyl group.

  In the present invention, the fluorine concentration of the fluororubber is 65% by mass or more. This means that the fluorine rubber has a high fluorine concentration. By containing a cross-linked fluororubber having a high fluorine concentration in the toner release layer, the action of repelling the binder resin, which is the main component of the toner, on the surface of the toner release layer can be further enhanced. it can. As a result, better toner release properties can be imparted to the toner release layer.

<Silicone surfactant>
In the present invention, the silicone-based surfactant is a nonionic surfactant having a hydrophobic group composed of dimethylpolysiloxane and a hydrophilic group composed of polyalkylene oxide. It is considered that the silicone-based surfactant increases the affinity with the wax due to the dimethyl group, and the effect of improving the wettability of the wax can be obtained.

  Silicone surfactants can be mainly classified into three types of structures. That is, a side chain-modified type having a structure in which polyoxyalkylene is bonded to a side chain of a dimethylpolysiloxane skeleton represented by the following formula (1), a dimethylpolysiloxane skeleton represented by the following formula (2) A terminal-modified type having a structure in which a polyoxyalkylene is bonded to the terminal thereof, and a copolymer type having a structure in which dimethylpolysiloxane and polyoxyalkylene are alternately and repeatedly bonded as represented by the following formula (3). Among these, a copolymer type represented by the formula (3) is more preferable because it has the best dispersibility with respect to fluororubber.

  As a compounding quantity of a silicone type surfactant, it is more preferable that it is the range of 20-40 mass parts with respect to 100 mass parts of fluororubber. By setting the blending amount within the above range, an effect of improving the affinity with the wax can be obtained, and a decrease in dispersibility in the fluororubber due to aggregation of the silicone surfactant can be suppressed.

  The toner release layer according to the present invention preferably has a cross-linked product of fluororubber and silicone surfactant and a cross-linked product of fluorosurfactant on the surface. According to this configuration, the action of repelling the binder resin that is the main component of the toner can be obtained by including the fluororubber having a high fluorine concentration. Further, by including a crosslinked product of a silicone surfactant and a crosslinked product of a fluorine surfactant, an effect of improving the affinity with the wax component in the toner can be obtained.

Further, the fluorosurfactant according to the present invention also has an effect of improving the dispersibility between the fluororubber having a high fluorine concentration and the silicone surfactant in the toner release layer forming process of the present invention.
That is, the toner release layer according to the present invention is obtained by applying the coating liquid for forming the toner release layer by dissolving the above-described fluororubber, silicone surfactant, and fluorine surfactant in an organic solvent. The film can be formed by forming a film on the heat conductive layer and curing the coating film.

  At this time, when a fluorine-based surfactant is not blended in the coating liquid for forming the toner release layer, a silicone-based surfactant is added to the fluorine rubber having a high fluorine concentration in the coating film of the coating solution. Aggregates without dispersion, resulting in layer separation. As a result, the toner release layer obtained as a result is almost entirely composed of a crosslinked product of a silicone surfactant. However, when a fluorosurfactant is blended in the coating liquid for forming the toner release layer, the affinity between the fluorosurfactant perfluoroalkyl group and the fluororubber having a high fluorine concentration, and the fluorochemical Aggregation of the silicone surfactant in the coating film is suppressed by the affinity between the hydrophilic group of the surfactant and the hydrophilic group of the silicone surfactant. As a result, a toner release layer having a sea-island structure in which a domain (island phase) of a cross-linked silicone surfactant is dispersed in a fluororubber matrix (sea phase) having a high fluorine concentration. Here, the diameter of the island phase is preferably 20 μm or less.

  The surface of the toner release layer according to the present invention is characterized in that a fluorine rubber having a high fluorine concentration, a crosslinked product of a silicone surfactant, and a crosslinked product of a fluorine surfactant are present. Although the fluorine concentration of the fluororubber is high, the effect of repelling the binder resin, which is the main component of the toner, can be obtained, but the effect of improving the affinity with the wax by the silicone surfactant is somewhat inhibited. However, the action of the lipophilic group of the fluorosurfactant supplementally improves the affinity with the wax and maintains the action of repelling the binder resin even when the fluorine concentration of the fluororubber is increased. It was found in the present invention that the affinity with is not inhibited.

  In the present invention, a layer coated by solution coating is formed on a substrate, and then the layer is crosslinked and cured to form a toner release layer. At this time, since curing inhibition may occur due to oxygen present in the air, it is preferable to crosslink in a nitrogen atmosphere in order to block oxygen that causes curing inhibition. An organic peroxide can be preliminarily blended in the coating solution, and the organic peroxide can be decomposed and crosslinked by heating, or can be crosslinked by irradiation with an electron beam.

  From the viewpoint of surface energy, the toner release layer of the present invention does not contain various fillers, for example, reinforcing fillers at all, or a mixture 100 of a fluororubber having an ether group in the molecule and a silicone surfactant 100. It is preferable to blend 5 parts by mass or less of reinforcing filler with respect to parts by mass. If the release layer contains too much filler, toner releasability may deteriorate, which is not preferable.

  The fixing member having the toner release layer according to the present invention can be manufactured, for example, as follows. First, a fluororubber comprising a terpolymer of vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl vinyl ether and having a fluorine concentration of 65% by mass or more, a silicone surfactant, a hydrophilic group, and a lipophilic oil A fluorosurfactant having a group and a perfluoroalkyl group having 4 to 6 carbon atoms is dissolved in at least an organic solvent to prepare a coating solution for forming a toner release layer. Next, the coating solution is applied onto the surface of the belt or roller on which the heat conductive silicone rubber layer and the adhesive layer are formed in advance, and after drying, the coating film is crosslinked by electron beam irradiation. The fixing member can be produced through secondary crosslinking in a normal heating oven. Although it does not specifically limit as a coating method, For example, spray coating, slit coating, blade coating, roll coating, dip coating etc. can be mentioned. The thickness of the toner release layer may be appropriately determined as necessary, but it is usually preferably 10 μm or more in order to ensure sufficient scratch resistance and abrasion resistance. Moreover, it is desirable that it is 150 micrometers or less from points, such as thermal conductivity to the surface.

  In the case of forming a heat conductive silicone rubber layer, a known method, for example, a method in which a silicone rubber material is injected into a mold and heat-cured, or a silicone polymer layer is formed by coating and heated in a heating oven or the like. What is necessary is just to produce by the method of hardening. The thickness of the silicone rubber layer is preferably 50 μm or more for reasons such as ensuring followability to a recording material such as paper, and is preferably 5 mm or less from the viewpoint of thermal conductivity. The adhesive layer may be formed by a known method.

  The fixing member of the present invention may be in any form such as a fixing belt, a fixing roller, a pressure belt, or a pressure roller.

  Next, the fixing device of the present invention will be described. The fixing device of the present invention is a fixing device used in an electrophotographic image forming apparatus, and the fixing member of the present invention is disposed in the fixing device as a fixing belt or a fixing roller and / or a pressure belt or a pressure roller. It is what has been. The electrophotographic image forming apparatus includes a photosensitive member, a means for forming a latent image, a means for developing the formed latent image with toner, a means for transferring the developed toner image to a recording material, and a toner image on the recording material. Examples thereof include an electrophotographic image forming apparatus having a fixing means.

  An example of a low pressure type fixing device according to the present invention is shown schematically in FIG. In FIG. 2, reference numeral 4 denotes an endless belt-like fixing belt, which is inscribed with respect to the belt guide member 5 and the stay 6 with a margin in circumference. 7 is a heating substrate, and an electric resistance material such as silver palladium (Ag / Pd), which generates heat when current flows on the heating substrate made of alumina, ceramic, or the like, is applied in a linear or belt shape by screen printing or the like. There is a layer. Further, a glass coating layer having a thickness of about 10 μm is sequentially formed thereon in order to ensure the protection and insulation of the electric resistance material. Further, a thermistor is in contact with the back surface of the heating body substrate, and the surface temperature of the fixing belt 4 is maintained at a temperature at which fixing can be performed by controlling the power to the electric resistance material according to the temperature detected by the thermistor. Can do.

  The pressure roller 8 is in pressure contact with the heating body substrate via the fixing belt 4 and is rotationally driven by a pressure roller driving unit. The pressure roller 8 is driven to rotate, and the fixing belt 4 rotates following the rotation. A recording material such as paper on which an unfixed image is formed is nipped and conveyed between the fixing belt 4 and the pressure roller 8, whereby the unfixed image is heated and fixed to the recording material. This fixing device is a low pressure type fixing device.

  Here, the fixing device of the fixing belt and the pressure roller is taken as an example. However, the fixing device of the present invention uses the fixing member of the present invention as the fixing belt or the fixing roller and / or the pressure belt or the pressure. What is necessary is just to have as a roller, and is not restricted to what was shown in FIG.

  Hereinafter, details of the present invention will be described by way of examples.

The dispersion form of the rubber constituting the toner release layer was examined by observing the rubber surface with a scanning electron microscope (JSM-5600LV, manufactured by JEOL Ltd.) and energy dispersive X-ray analysis (EDS elemental analysis). . In the present invention, the diameter of the island phase is the elliptical major axis when the maximum diameter of the island phase is fixed as the major axis direction, the minor axis is newly set, and an elliptical shape equal to the area of the island phase is set. The average value with the minor axis was obtained as the average value of 50 island phases. The dispersion form of rubber was ranked as follows.
○: Confirmed dispersion of sea-island structure consisting of sea phase made of fluoro rubber and island phase made of cross-linked product of silicone surfactant ×: Made of cross-linked product of sea phase made of fluoro rubber and silicone-based surfactant Unidentified dispersion of sea-island structure consisting of islands

  In addition, the contact angle of the binder resin, which is the toner main component, and the wax, which is the toner release agent component, with respect to the rubber surface is the contact angle for each of the binder resin and wax of the color toner used in the evaluation of the toner releasability. Using a meter (DropMaster 500 (temperature controller connection), manufactured by Kyowa Interface Science Co., Ltd.), measurement was performed 5 times while heating at 200 ° C., and the average value was obtained.

The evaluation of toner releasability is based on the result of fixing a toner image by incorporating a fixing belt formed with rubber constituting the toner release layer of the present invention into a fixing device of a color printer (LBP5400, manufactured by Canon Inc.). did. The evaluation results were ranked as follows.
A: Even when 30,000 sheets are passed, there is no paper wrapping and no toner adhesion is observed.
○: Even when 20,000 sheets are passed, there is no paper wrapping and no toner adhesion is observed.
Δ: Toner adhesion occurred when the number of sheets passed was less than 1000.
X: Toner adhesion occurred on the first sheet.
XX: Paper wrapping occurred on the first sheet.

[Example 1]
14 g of fluororubber (trade name LT252, manufactured by Daikin Industries, Ltd.) consisting of a terpolymer of vinylidene fluoride, tetrafluoroethylene and perfluoromethyl vinyl ether and having a fluorine concentration of 66.5% by mass, silicone-based interface Activating agent (trade name FZ2207, manufactured by Toray Dow Corning Silicone Co., Ltd.) 4.2 g, fluorinated surfactant having a hydrophilic group and a lipophilic group, and having 6 perfluoroalkyl groups (Megafac F) -558, DIC Corporation, active ingredient approx. 30%) 3.0 g, triallyl isocyanurate (trade name Taik, Nippon Kasei Co., Ltd.) 0.9 g dissolved in 186 g of organic solvent methyl ethyl ketone. A liquid was prepared. This coating solution was spray-coated on a primer-treated rubber-coated base material (SUS-coated base material (thickness 35 μm) having a heat conductive silicone rubber thickness of 300 μm) and dried. Thereafter, the film is crosslinked by irradiating with an electron beam in a nitrogen atmosphere, and subjected to secondary crosslinking in a heating oven at 180 ° C. for 24 hours to form a toner release layer made of the rubber of the present invention having a thickness of 30 μm. Was made.

  The rubber was dispersed in a sea-island structure in which fluororubber was a sea phase and a cross-linked product of a silicone surfactant was an island phase, and the island phase had a diameter of 10 μm. The contact angle of the binder resin with respect to the rubber was 73 °, and the contact angle of the wax was 62 °.

  As a result of evaluating the toner releasability of the produced fixing belt, no initial toner offset or paper winding JAM occurred, and even when 30,000 sheets were passed, there was no practical problem and a high-quality toner fixed image was obtained.

[Example 2]
A fluorosurfactant having a hydrophilic group and a lipophilic group and having a perfluoroalkyl group having 4 carbon atoms (trade name: PF-7002, manufactured by OMNOVA Solutions, active ingredient: about 100 %) 0.91 g was mixed. Other than that was carried out similarly to Example 1, the toner release layer which consists of rubber | gum of this invention was formed, and the fixing belt was produced.

  The dispersion form of rubber was a sea-island structure in which fluororubber was a sea phase and a crosslinked product of a silicone-based surfactant was an island phase, and the diameter of the island phase was 20 μm. The contact angle of the binder resin with respect to the rubber was 73 °, and the contact angle of the wax was 64 °.

  As a result of evaluating the toner releasability of the produced fixing belt, no initial toner offset or paper winding JAM occurred, and even when 30,000 sheets were passed, there was no practical problem and a high-quality toner fixed image was obtained.

[Example 3]
Fluororubber is made of a terpolymer of vinylidene fluoride, tetrafluoroethylene, and perfluoromethyl vinyl ether and has a fluorine concentration of 66.0% by mass in 14 g of fluorine rubber (trade name Viton GFLT, manufactured by DuPont). did. Other than that was carried out similarly to Example 2, the toner release layer which consists of rubber | gum of this invention was formed, and the fixing belt was produced.

  The dispersion form of rubber was a sea-island structure in which fluororubber was a sea phase and a crosslinked product of a silicone surfactant was an island phase, and the diameter of the island phase was 15 μm. The contact angle of the binder resin with respect to the rubber was 72 °, and the contact angle of the wax was 63 °.

  As a result of evaluating the toner releasability of the produced fixing belt, no initial toner offset or paper winding JAM occurred, and even when 30,000 sheets were passed, there was no practical problem and a high-quality toner fixed image was obtained.

[Example 4]
Fluororubber is made of a terpolymer of vinylidene fluoride, tetrafluoroethylene, and perfluoromethyl vinyl ether and has a fluorine concentration of 65.0 mass% (trade name LT304, manufactured by Daikin Industries, Ltd.) 14 g did. Other than that was carried out similarly to Example 2, the toner release layer which consists of rubber | gum of this invention was formed, and the fixing belt was produced.

  The rubber was dispersed in a sea-island structure in which fluororubber was a sea phase and a cross-linked product of a silicone surfactant was an island phase, and the island phase had a diameter of 10 μm. The contact angle of the binder resin with respect to the rubber was 71 °, and the contact angle of the wax was 62 °.

  As a result of evaluating the toner releasability of the prepared fixing belt, no initial toner offset or paper wrapping JAM occurred, and a high-quality toner-fixed image was obtained with no practical problems even when 20,000 sheets were passed.

[Example 5]
The blending amount of the fluorosurfactant (Megafac F-558, manufactured by DIC Corporation, active ingredient about 30%) having a hydrophilic group and a lipophilic group and having 6 carbon atoms in the perfluoroalkyl group is 6 .1 g. Other than that was carried out similarly to Example 1, the toner release layer which consists of rubber | gum of this invention was formed, and the fixing belt was produced.

  The rubber was dispersed in a sea-island structure in which fluororubber was a sea phase and a cross-linked product of a silicone surfactant was an island phase, and the island phase had a diameter of 10 μm. The contact angle of the binder resin with respect to the rubber was 72 °, and the contact angle of the wax was 60 °.

  As a result of evaluating the toner releasability of the produced fixing belt, no initial toner offset or paper winding JAM occurred, and even when 30,000 sheets were passed, there was no practical problem and a high-quality toner fixed image was obtained.

[Example 6]
The blending amount of a fluorosurfactant having a hydrophilic group and a lipophilic group and having 6 carbon atoms of a perfluoroalkyl group (Megafac F-558, manufactured by DIC Corporation, active ingredient: about 30%) is 9 .1 g. Other than that was carried out similarly to Example 1, the toner release layer which consists of rubber | gum of this invention was formed, and the fixing belt was produced.

  The rubber was dispersed in a sea-island structure in which fluororubber was a sea phase and a cross-linked product of a silicone surfactant was an island phase, and the island phase had a diameter of 10 μm. The contact angle of the binder resin with respect to the rubber was 71 °, and the contact angle of the wax was 58 °.

  As a result of evaluating the toner releasability of the prepared fixing belt, no initial toner offset or paper wrapping JAM occurred, and a high-quality toner-fixed image was obtained with no practical problems even when 20,000 sheets were passed.

[Example 7]
A toner release layer made of the rubber of the present invention is formed in the same manner as in Example 1 except that the amount of the silicone surfactant (trade name FZ2207, manufactured by Toray Dow Corning Silicone Co., Ltd.) is 2.8 g. Thus, a fixing belt was produced.

  The dispersion form of rubber was a sea-island structure in which fluororubber was a sea phase and a crosslinked product of a silicone surfactant was an island phase, and the diameter of the island phase was 5 μm. The contact angle of the binder resin to this rubber was 74 °, and the contact angle of wax was 65 °.

  As a result of evaluating the toner releasability of the prepared fixing belt, no initial toner offset or paper wrapping JAM occurred, and a high-quality toner-fixed image was obtained with no practical problems even when 20,000 sheets were passed.

[Example 8]
A toner release layer made of the rubber of the present invention is formed in the same manner as in Example 1 except that the amount of the silicone-based surfactant (trade name FZ2207, manufactured by Toray Dow Corning Silicone Co., Ltd.) is 5.6 g. Thus, a fixing belt was produced.

  The dispersion form of rubber was a sea-island structure in which fluororubber was a sea phase and a crosslinked product of a silicone-based surfactant was an island phase, and the diameter of the island phase was 20 μm. The contact angle of the binder resin with respect to the rubber was 73 °, and the contact angle of the wax was 60 °.

  As a result of evaluating the toner releasability of the produced fixing belt, no initial toner offset or paper winding JAM occurred, and even when 30,000 sheets were passed, there was no practical problem and a high-quality toner fixed image was obtained.

[Comparative Example 1]
A fluorosurfactant having a hydrophilic group and a lipophilic group and having a perfluoroalkyl group having 8 carbon atoms (trade name: Megafax F-482, manufactured by DIC Corporation, active ingredient About 20%) 4.6 g was blended. Other than that was carried out similarly to Example 1, the toner release layer which consists of rubber | gum of this invention was formed, and the fixing belt was produced.

  The dispersion form of rubber was a sea-island structure in which fluororubber was a sea phase and a crosslinked product of a silicone-based surfactant was an island phase, and the diameter of the island phase was 20 μm. The contact angle of the binder resin with respect to the rubber was 75 °, and the contact angle of the wax was 69 °.

  As a result of evaluating the toner releasability of the produced fixing belt, toner offset occurred on the first sheet.

[Comparative Example 2]
A fluorosurfactant having a hydrophilic group and a lipophilic group and having a perfluoroalkyl group having 2 carbon atoms (trade name: PolyFox 6520, manufactured by OMNOVA Solutions, active ingredient: about 100%) 0.91 g was blended. Other than that was carried out similarly to Example 1, the toner release layer which consists of rubber | gum of this invention was formed, and the fixing belt was produced.

  As for the dispersion form of the rubber, the fluororubber and the silicone surfactant were not dispersed, and the rubber surface was almost a crosslinked product of the silicone surfactant. The contact angle of the binder resin with respect to the rubber was 65 °, and the contact angle of the wax was 50 °.

  As a result of evaluating the toner releasability of the produced fixing belt, paper wrap JAM occurred on the first sheet.

[Comparative Example 3]
The fluororubber was made of a terpolymer of vinylidene fluoride, tetrafluoroethylene and perfluoromethyl vinyl ether, and a fluororubber (trade name LT302, manufactured by Daikin Industries, Ltd.) having a fluorine concentration of 64.5% by mass. . Other than that was carried out similarly to Example 2, the toner release layer which consists of rubber | gum of this invention was formed, and the fixing belt was produced.

  The rubber was dispersed in a sea-island structure in which fluororubber was a sea phase and a crosslinked product of a silicone surfactant was an island phase, and the diameter of the island phase was 1 μm. The contact angle of the binder resin with respect to the rubber was 69 °, and the contact angle of the wax was 62 °.

  As a result of evaluating the toner releasability of the produced fixing belt, a toner offset occurred until 1000 sheets were passed.

[Comparative Example 4]
14 g of fluororubber (trade name LT252, manufactured by Daikin Industries, Ltd.) consisting of a terpolymer of vinylidene fluoride, tetrafluoroethylene and perfluoromethyl vinyl ether and having a fluorine concentration of 66.5% by mass, triallyl isocyan A coating solution was prepared by dissolving 0.56 g of nurate (trade name, manufactured by Nippon Kasei Co., Ltd.) in 86 g of methyl ethyl ketone, which is an organic solvent. This coating solution was spray-coated on a primer-treated rubber-coated base material (SUS-coated base material (thickness 35 μm) having a heat conductive silicone rubber thickness of 300 μm) and dried. After that, crosslinking was performed by irradiating with an electron beam in a nitrogen atmosphere, and secondary crosslinking was performed in a heating oven at 180 ° C. for 24 hours to form a toner release layer made of rubber having a thickness of 30 μm, and a fixing belt was manufactured. .

  The contact angle of the binder resin with respect to the rubber was 76 °, and the contact angle of the wax was 71 °.

  As a result of evaluating the toner releasability of the produced fixing belt, toner offset occurred on the first sheet.

[Comparative Example 5]
14 g of fluororubber (trade name LT252, manufactured by Daikin Industries, Ltd.) consisting of a terpolymer of vinylidene fluoride, tetrafluoroethylene and perfluoromethyl vinyl ether and having a fluorine concentration of 66.5% by mass, 2.3 g of a fluorosurfactant having a lipophilic group and a perfluoroalkyl group having 6 carbon atoms (Megafac F-558, manufactured by DIC Corporation, approximately 30% active ingredient), triallyl isocyanurate 0.56 g (trade name, manufactured by Nippon Chemical Co., Ltd.) was dissolved in 186 g of methyl ethyl ketone, which is an organic solvent. The dissolved solution was spray-coated on a primer-treated rubber-coated substrate (SUS-coated substrate (thickness 35 μm) having a thickness of 300 μm of thermally conductive silicone rubber) and dried. After that, crosslinking was performed by irradiating with an electron beam in a nitrogen atmosphere, and secondary crosslinking was performed in a heating oven at 180 ° C. for 24 hours to form a toner release layer made of rubber having a thickness of 30 μm, and a fixing belt was manufactured. .

  The contact angle of the binder resin with respect to the rubber was 76 °, and the contact angle of the wax was 66 °.

  As a result of evaluating the toner releasability of the produced fixing belt, a toner offset occurred until 1000 sheets were passed.

[Comparative Example 6]
14 g of fluororubber (trade name LT252, manufactured by Daikin Industries, Ltd.) consisting of a terpolymer of vinylidene fluoride, tetrafluoroethylene and perfluoromethyl vinyl ether and having a fluorine concentration of 66.5% by mass, silicone-based interface 4.2 g of an activator (trade name FZ2207, manufactured by Toray Dow Corning Silicone Co., Ltd.) and 0.9 g of triallyl isocyanurate (trade name Taike, manufactured by Nippon Kasei Chemical Co., Ltd.) were dissolved in 186 g of methyl ethyl ketone, which is an organic solvent. The dissolved solution was spray-coated on a primer-treated rubber-coated substrate (SUS-coated substrate (thickness 35 μm) having a thickness of 300 μm of thermally conductive silicone rubber) and dried. After that, crosslinking was performed by irradiating with an electron beam in a nitrogen atmosphere, and secondary crosslinking was performed in a heating oven at 180 ° C. for 24 hours to form a toner release layer made of rubber having a thickness of 30 μm, and a fixing belt was manufactured. .

  The rubber was dispersed in such a manner that the fluororubber and the silicone surfactant were not dispersed and the layers were almost separated, and the rubber surface was almost a crosslinked product of the silicone surfactant. The contact angle of the binder resin with respect to the rubber was 65 °, and the contact angle of the wax was 50 °.

  As a result of evaluating the toner releasability of the produced fixing belt, paper wrap JAM occurred on the first sheet.

  Table 1 shows the material blending amounts of Examples 1 to 8 and Comparative Examples 1 to 6.

  * Described in Table 1 indicates the blending amount (parts by mass) of the silicone surfactant with respect to 100 parts by mass of the fluororubber. ** indicates the carbon number of the perfluoroalkyl group. *** indicates the blending amount (parts by mass) of the fluorosurfactant with respect to 100 parts by mass in total of the fluororubber and the silicone surfactant.

  For example, when the type of fluorosurfactant is “C6” and the blending amount is “5 parts”, the perfluoroalkyl group has 6 carbon atoms and the blending amount of fluorosurfactant is fluororubber and silicone. It shows that it is 5 mass parts with respect to 100 mass parts in total with surfactant.

  Next, Table 2 shows the evaluation results of Examples 1 to 8 and Comparative Examples 1 to 6.

  Hereinafter, the evaluation result of an Example and a comparative example is demonstrated.

  When the carbon number of the perfluoroalkyl group of the fluorosurfactant is compared, it can be seen that Examples 1 and 2 have 6 or 4 carbon atoms and the wettability of the wax is good. On the other hand, in Comparative Example 1 having 8 carbon atoms, the perfluoroalkyl group is easily exposed on the rubber surface, which inhibits the effect of improving the wettability of the wax due to the incorporation of the silicone surfactant. It is considered that the wettability of the wax is not good.

  When Comparative Examples 4 and 5 are compared, it can be seen that adding a fluorosurfactant having 6 carbon atoms in the perfluoroalkyl group to fluororubber has an effect of improving wax wettability.

  However, with regard to the blending amount of the fluorosurfactant, it can be seen from Examples 1, 5, and 6 that when the blending amount is increased, the wettability of the wax is slightly improved, but the effect of repelling the binder resin is slightly decreased. .

  Comparing the fluorine concentration of the fluororubber, it can be seen that Examples 2 to 4 have a fluorine concentration of 65% by mass or more, and have an effect of repelling the binder resin as compared with Comparative Example 3 of less than 65% by mass.

  Comparing the silicone surfactants, the wettability of the wax is improved by blending 20 to 40 parts by mass of Examples 1, 7, and 8 with respect to Comparative Examples 4 and 5 which are not blended. I understand.

  From the above results, Examples 1 to 8 are fixing members having a toner release layer, and the toner release layer is a ternary copolymer of vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl vinyl ether. Fluorine rubber comprising a combination and having a fluorine concentration of 65% by mass or more, a silicone surfactant, a hydrophilic group and a lipophilic group, and a perfluoroalkyl group having 4 to 6 carbon atoms A fixing member, which is a crosslinked rubber of a mixture of at least three kinds with a surfactant. This fixing member is considered to have good toner releasability because it repels the binder resin that is the main component of the toner and has good wettability with the wax that is the toner release agent component.

  On the other hand, in Comparative Example 1, since the perfluoroalkyl group of the fluorosurfactant has 8 carbon atoms, the perfluoroalkyl group is easily exposed on the rubber surface, and a silicone surfactant is blended. This hinders the effect of improving the wettability of the wax. Therefore, it is considered that the toner releasability is not good. In Comparative Example 2, the perfluoroalkyl group of the fluorosurfactant has 2 carbon atoms, the fluororubber having a high fluorine concentration and the silicone surfactant are aggregated without being dispersed, and the rubber surface is almost silicone-based. It is a surfactant. For this reason, it is considered that the effect of repelling the binder resin of the toner main component cannot be obtained and the toner releasability is not good. In Comparative Example 3, since the fluorine concentration of the fluororubber is less than 65% by mass and the effect of repelling the binder resin of the toner main component is insufficient, it is considered that the toner releasability is not good. In Comparative Examples 4 and 5, since no silicone surfactant is blended and the wettability of the wax, which is a toner release agent component, is not good, it is considered that the toner release property is not good. In Comparative Example 6, no fluorosurfactant is blended, the fluororubber having a high fluorine concentration and the silicone surfactant are aggregated without being dispersed, and the rubber surface is almost a silicone surfactant. For this reason, it is considered that the effect of repelling the binder resin of the toner main component cannot be obtained and the toner releasability is not good.

DESCRIPTION OF SYMBOLS 1 Toner release layer 2 Heat conductive layer 3 Base material 4 Fixing belt 5 Belt guide member 6 Stay 7 Heating substrate 8 Pressure roller

Claims (7)

A fixing member having a base material and a toner release layer,
The toner release layer contains a cross-linked product of a mixture of fluororubber, silicone surfactant, and fluorosurfactant,
The fluororubber is composed of a terpolymer of vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl vinyl ether, and the fluorine concentration is 65% by mass or more.
The fixing member, wherein the fluorosurfactant has a hydrophilic group and a lipophilic group, and the perfluoroalkyl group has 4 to 6 carbon atoms. The toner release layer is
A sea phase containing the fluororubber;
And an island phase composed of a crosslinked product of the silicone-based surfactant, and the fluororubber, the crosslinked product of the silicone-based surfactant and the fluorine-based product on the surface of the toner release layer. The fixing member according to claim 1, wherein a cross-linked product of a surfactant is present.   The fixing member according to claim 2, wherein the island phase has a diameter of 20 μm or less. The toner release layer is
A fluororubber comprising a terpolymer of vinylidene fluoride, tetrafluoroethylene and perfluoroalkyl vinyl ether, and having a fluorine concentration of 65% by mass or more;
A silicone surfactant;
An electron beam is applied to a coating film of a coating liquid for forming a toner release layer, which includes a hydrophilic surfactant and a lipophilic group and a fluorosurfactant having a perfluoroalkyl group having 4 to 6 carbon atoms. The fixing member according to claim 1, wherein the fixing member is formed by irradiation and curing. A method for manufacturing a fixing member according to claim 1,
A fluororubber comprising a terpolymer of vinylidene fluoride, tetrafluoroethylene and perfluoroalkyl vinyl ether, and having a fluorine concentration of 65% by mass or more;
A silicone surfactant;
Curing a coating film of a coating liquid for forming a toner release layer, comprising a fluorosurfactant having a hydrophilic group and a lipophilic group and having a perfluoroalkyl group having 4 to 6 carbon atoms. A method for producing a fixing member, comprising a step of forming a toner release layer.   The method for producing a fixing member according to claim 5, wherein the coating film is cured by irradiating the coating film with an electron beam.   A fixing device used in an electrophotographic image forming apparatus, wherein the fixing device includes the fixing member according to claim 1.

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